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1#include <linux/kernel.h>
2#include <linux/module.h>
3#include <linux/interrupt.h>
4#include <linux/irq.h>
5#include <linux/spinlock.h>
6#include <linux/list.h>
7#include <linux/device.h>
8#include <linux/err.h>
9#include <linux/debugfs.h>
10#include <linux/seq_file.h>
11#include <linux/gpio.h>
12#include <linux/of_gpio.h>
13#include <linux/idr.h>
14#include <linux/slab.h>
15#include <linux/acpi.h>
16#include <linux/gpio/driver.h>
17#include <linux/gpio/machine.h>
18#include <linux/pinctrl/consumer.h>
19#include <linux/idr.h>
20#include <linux/cdev.h>
21#include <linux/fs.h>
22#include <linux/uaccess.h>
23#include <uapi/linux/gpio.h>
24
25#include "gpiolib.h"
26
27#define CREATE_TRACE_POINTS
28#include <trace/events/gpio.h>
29
30/* Implementation infrastructure for GPIO interfaces.
31 *
32 * The GPIO programming interface allows for inlining speed-critical
33 * get/set operations for common cases, so that access to SOC-integrated
34 * GPIOs can sometimes cost only an instruction or two per bit.
35 */
36
37
38/* When debugging, extend minimal trust to callers and platform code.
39 * Also emit diagnostic messages that may help initial bringup, when
40 * board setup or driver bugs are most common.
41 *
42 * Otherwise, minimize overhead in what may be bitbanging codepaths.
43 */
44#ifdef DEBUG
45#define extra_checks 1
46#else
47#define extra_checks 0
48#endif
49
50/* Device and char device-related information */
51static DEFINE_IDA(gpio_ida);
52static dev_t gpio_devt;
53#define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
54static struct bus_type gpio_bus_type = {
55 .name = "gpio",
56};
57
58/* gpio_lock prevents conflicts during gpio_desc[] table updates.
59 * While any GPIO is requested, its gpio_chip is not removable;
60 * each GPIO's "requested" flag serves as a lock and refcount.
61 */
62DEFINE_SPINLOCK(gpio_lock);
63
64static DEFINE_MUTEX(gpio_lookup_lock);
65static LIST_HEAD(gpio_lookup_list);
66LIST_HEAD(gpio_devices);
67
68static void gpiochip_free_hogs(struct gpio_chip *chip);
69static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
70
71static bool gpiolib_initialized;
72
73static inline void desc_set_label(struct gpio_desc *d, const char *label)
74{
75 d->label = label;
76}
77
78/**
79 * Convert a GPIO number to its descriptor
80 */
81struct gpio_desc *gpio_to_desc(unsigned gpio)
82{
83 struct gpio_device *gdev;
84 unsigned long flags;
85
86 spin_lock_irqsave(&gpio_lock, flags);
87
88 list_for_each_entry(gdev, &gpio_devices, list) {
89 if (gdev->base <= gpio &&
90 gdev->base + gdev->ngpio > gpio) {
91 spin_unlock_irqrestore(&gpio_lock, flags);
92 return &gdev->descs[gpio - gdev->base];
93 }
94 }
95
96 spin_unlock_irqrestore(&gpio_lock, flags);
97
98 if (!gpio_is_valid(gpio))
99 WARN(1, "invalid GPIO %d\n", gpio);
100
101 return NULL;
102}
103EXPORT_SYMBOL_GPL(gpio_to_desc);
104
105/**
106 * Get the GPIO descriptor corresponding to the given hw number for this chip.
107 */
108struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
109 u16 hwnum)
110{
111 struct gpio_device *gdev = chip->gpiodev;
112
113 if (hwnum >= gdev->ngpio)
114 return ERR_PTR(-EINVAL);
115
116 return &gdev->descs[hwnum];
117}
118
119/**
120 * Convert a GPIO descriptor to the integer namespace.
121 * This should disappear in the future but is needed since we still
122 * use GPIO numbers for error messages and sysfs nodes
123 */
124int desc_to_gpio(const struct gpio_desc *desc)
125{
126 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
127}
128EXPORT_SYMBOL_GPL(desc_to_gpio);
129
130
131/**
132 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
133 * @desc: descriptor to return the chip of
134 */
135struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
136{
137 if (!desc || !desc->gdev || !desc->gdev->chip)
138 return NULL;
139 return desc->gdev->chip;
140}
141EXPORT_SYMBOL_GPL(gpiod_to_chip);
142
143/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
144static int gpiochip_find_base(int ngpio)
145{
146 struct gpio_device *gdev;
147 int base = ARCH_NR_GPIOS - ngpio;
148
149 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
150 /* found a free space? */
151 if (gdev->base + gdev->ngpio <= base)
152 break;
153 else
154 /* nope, check the space right before the chip */
155 base = gdev->base - ngpio;
156 }
157
158 if (gpio_is_valid(base)) {
159 pr_debug("%s: found new base at %d\n", __func__, base);
160 return base;
161 } else {
162 pr_err("%s: cannot find free range\n", __func__);
163 return -ENOSPC;
164 }
165}
166
167/**
168 * gpiod_get_direction - return the current direction of a GPIO
169 * @desc: GPIO to get the direction of
170 *
171 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
172 *
173 * This function may sleep if gpiod_cansleep() is true.
174 */
175int gpiod_get_direction(struct gpio_desc *desc)
176{
177 struct gpio_chip *chip;
178 unsigned offset;
179 int status = -EINVAL;
180
181 chip = gpiod_to_chip(desc);
182 offset = gpio_chip_hwgpio(desc);
183
184 if (!chip->get_direction)
185 return status;
186
187 status = chip->get_direction(chip, offset);
188 if (status > 0) {
189 /* GPIOF_DIR_IN, or other positive */
190 status = 1;
191 clear_bit(FLAG_IS_OUT, &desc->flags);
192 }
193 if (status == 0) {
194 /* GPIOF_DIR_OUT */
195 set_bit(FLAG_IS_OUT, &desc->flags);
196 }
197 return status;
198}
199EXPORT_SYMBOL_GPL(gpiod_get_direction);
200
201/*
202 * Add a new chip to the global chips list, keeping the list of chips sorted
203 * by range(means [base, base + ngpio - 1]) order.
204 *
205 * Return -EBUSY if the new chip overlaps with some other chip's integer
206 * space.
207 */
208static int gpiodev_add_to_list(struct gpio_device *gdev)
209{
210 struct gpio_device *prev, *next;
211
212 if (list_empty(&gpio_devices)) {
213 /* initial entry in list */
214 list_add_tail(&gdev->list, &gpio_devices);
215 return 0;
216 }
217
218 next = list_entry(gpio_devices.next, struct gpio_device, list);
219 if (gdev->base + gdev->ngpio <= next->base) {
220 /* add before first entry */
221 list_add(&gdev->list, &gpio_devices);
222 return 0;
223 }
224
225 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
226 if (prev->base + prev->ngpio <= gdev->base) {
227 /* add behind last entry */
228 list_add_tail(&gdev->list, &gpio_devices);
229 return 0;
230 }
231
232 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
233 /* at the end of the list */
234 if (&next->list == &gpio_devices)
235 break;
236
237 /* add between prev and next */
238 if (prev->base + prev->ngpio <= gdev->base
239 && gdev->base + gdev->ngpio <= next->base) {
240 list_add(&gdev->list, &prev->list);
241 return 0;
242 }
243 }
244
245 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
246 return -EBUSY;
247}
248
249/**
250 * Convert a GPIO name to its descriptor
251 */
252static struct gpio_desc *gpio_name_to_desc(const char * const name)
253{
254 struct gpio_device *gdev;
255 unsigned long flags;
256
257 spin_lock_irqsave(&gpio_lock, flags);
258
259 list_for_each_entry(gdev, &gpio_devices, list) {
260 int i;
261
262 for (i = 0; i != gdev->ngpio; ++i) {
263 struct gpio_desc *desc = &gdev->descs[i];
264
265 if (!desc->name || !name)
266 continue;
267
268 if (!strcmp(desc->name, name)) {
269 spin_unlock_irqrestore(&gpio_lock, flags);
270 return desc;
271 }
272 }
273 }
274
275 spin_unlock_irqrestore(&gpio_lock, flags);
276
277 return NULL;
278}
279
280/*
281 * Takes the names from gc->names and checks if they are all unique. If they
282 * are, they are assigned to their gpio descriptors.
283 *
284 * Warning if one of the names is already used for a different GPIO.
285 */
286static int gpiochip_set_desc_names(struct gpio_chip *gc)
287{
288 struct gpio_device *gdev = gc->gpiodev;
289 int i;
290
291 if (!gc->names)
292 return 0;
293
294 /* First check all names if they are unique */
295 for (i = 0; i != gc->ngpio; ++i) {
296 struct gpio_desc *gpio;
297
298 gpio = gpio_name_to_desc(gc->names[i]);
299 if (gpio)
300 dev_warn(&gdev->dev,
301 "Detected name collision for GPIO name '%s'\n",
302 gc->names[i]);
303 }
304
305 /* Then add all names to the GPIO descriptors */
306 for (i = 0; i != gc->ngpio; ++i)
307 gdev->descs[i].name = gc->names[i];
308
309 return 0;
310}
311
312/**
313 * gpio_ioctl() - ioctl handler for the GPIO chardev
314 */
315static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
316{
317 struct gpio_device *gdev = filp->private_data;
318 struct gpio_chip *chip = gdev->chip;
319 int __user *ip = (int __user *)arg;
320
321 /* We fail any subsequent ioctl():s when the chip is gone */
322 if (!chip)
323 return -ENODEV;
324
325 /* Fill in the struct and pass to userspace */
326 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
327 struct gpiochip_info chipinfo;
328
329 strncpy(chipinfo.name, dev_name(&gdev->dev),
330 sizeof(chipinfo.name));
331 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
332 strncpy(chipinfo.label, gdev->label,
333 sizeof(chipinfo.label));
334 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
335 chipinfo.lines = gdev->ngpio;
336 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
337 return -EFAULT;
338 return 0;
339 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
340 struct gpioline_info lineinfo;
341 struct gpio_desc *desc;
342
343 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
344 return -EFAULT;
345 if (lineinfo.line_offset > gdev->ngpio)
346 return -EINVAL;
347
348 desc = &gdev->descs[lineinfo.line_offset];
349 if (desc->name) {
350 strncpy(lineinfo.name, desc->name,
351 sizeof(lineinfo.name));
352 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
353 } else {
354 lineinfo.name[0] = '\0';
355 }
356 if (desc->label) {
357 strncpy(lineinfo.consumer, desc->label,
358 sizeof(lineinfo.consumer));
359 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
360 } else {
361 lineinfo.consumer[0] = '\0';
362 }
363
364 /*
365 * Userspace only need to know that the kernel is using
366 * this GPIO so it can't use it.
367 */
368 lineinfo.flags = 0;
369 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
370 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
371 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
372 test_bit(FLAG_EXPORT, &desc->flags) ||
373 test_bit(FLAG_SYSFS, &desc->flags))
374 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
375 if (test_bit(FLAG_IS_OUT, &desc->flags))
376 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
377 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
378 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
379 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
380 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
381 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
382 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
383
384 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
385 return -EFAULT;
386 return 0;
387 }
388 return -EINVAL;
389}
390
391/**
392 * gpio_chrdev_open() - open the chardev for ioctl operations
393 * @inode: inode for this chardev
394 * @filp: file struct for storing private data
395 * Returns 0 on success
396 */
397static int gpio_chrdev_open(struct inode *inode, struct file *filp)
398{
399 struct gpio_device *gdev = container_of(inode->i_cdev,
400 struct gpio_device, chrdev);
401
402 /* Fail on open if the backing gpiochip is gone */
403 if (!gdev || !gdev->chip)
404 return -ENODEV;
405 get_device(&gdev->dev);
406 filp->private_data = gdev;
407 return 0;
408}
409
410/**
411 * gpio_chrdev_release() - close chardev after ioctl operations
412 * @inode: inode for this chardev
413 * @filp: file struct for storing private data
414 * Returns 0 on success
415 */
416static int gpio_chrdev_release(struct inode *inode, struct file *filp)
417{
418 struct gpio_device *gdev = container_of(inode->i_cdev,
419 struct gpio_device, chrdev);
420
421 if (!gdev)
422 return -ENODEV;
423 put_device(&gdev->dev);
424 return 0;
425}
426
427
428static const struct file_operations gpio_fileops = {
429 .release = gpio_chrdev_release,
430 .open = gpio_chrdev_open,
431 .owner = THIS_MODULE,
432 .llseek = noop_llseek,
433 .unlocked_ioctl = gpio_ioctl,
434 .compat_ioctl = gpio_ioctl,
435};
436
437static void gpiodevice_release(struct device *dev)
438{
439 struct gpio_device *gdev = dev_get_drvdata(dev);
440
441 cdev_del(&gdev->chrdev);
442 list_del(&gdev->list);
443 ida_simple_remove(&gpio_ida, gdev->id);
444 kfree(gdev->label);
445 kfree(gdev->descs);
446 kfree(gdev);
447}
448
449static int gpiochip_setup_dev(struct gpio_device *gdev)
450{
451 int status;
452
453 cdev_init(&gdev->chrdev, &gpio_fileops);
454 gdev->chrdev.owner = THIS_MODULE;
455 gdev->chrdev.kobj.parent = &gdev->dev.kobj;
456 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
457 status = cdev_add(&gdev->chrdev, gdev->dev.devt, 1);
458 if (status < 0)
459 chip_warn(gdev->chip, "failed to add char device %d:%d\n",
460 MAJOR(gpio_devt), gdev->id);
461 else
462 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
463 MAJOR(gpio_devt), gdev->id);
464 status = device_add(&gdev->dev);
465 if (status)
466 goto err_remove_chardev;
467
468 status = gpiochip_sysfs_register(gdev);
469 if (status)
470 goto err_remove_device;
471
472 /* From this point, the .release() function cleans up gpio_device */
473 gdev->dev.release = gpiodevice_release;
474 get_device(&gdev->dev);
475 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
476 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
477 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
478
479 return 0;
480
481err_remove_device:
482 device_del(&gdev->dev);
483err_remove_chardev:
484 cdev_del(&gdev->chrdev);
485 return status;
486}
487
488static void gpiochip_setup_devs(void)
489{
490 struct gpio_device *gdev;
491 int err;
492
493 list_for_each_entry(gdev, &gpio_devices, list) {
494 err = gpiochip_setup_dev(gdev);
495 if (err)
496 pr_err("%s: Failed to initialize gpio device (%d)\n",
497 dev_name(&gdev->dev), err);
498 }
499}
500
501/**
502 * gpiochip_add_data() - register a gpio_chip
503 * @chip: the chip to register, with chip->base initialized
504 * Context: potentially before irqs will work
505 *
506 * Returns a negative errno if the chip can't be registered, such as
507 * because the chip->base is invalid or already associated with a
508 * different chip. Otherwise it returns zero as a success code.
509 *
510 * When gpiochip_add_data() is called very early during boot, so that GPIOs
511 * can be freely used, the chip->parent device must be registered before
512 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
513 * for GPIOs will fail rudely.
514 *
515 * gpiochip_add_data() must only be called after gpiolib initialization,
516 * ie after core_initcall().
517 *
518 * If chip->base is negative, this requests dynamic assignment of
519 * a range of valid GPIOs.
520 */
521int gpiochip_add_data(struct gpio_chip *chip, void *data)
522{
523 unsigned long flags;
524 int status = 0;
525 unsigned i;
526 int base = chip->base;
527 struct gpio_device *gdev;
528
529 /*
530 * First: allocate and populate the internal stat container, and
531 * set up the struct device.
532 */
533 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
534 if (!gdev)
535 return -ENOMEM;
536 gdev->dev.bus = &gpio_bus_type;
537 gdev->chip = chip;
538 chip->gpiodev = gdev;
539 if (chip->parent) {
540 gdev->dev.parent = chip->parent;
541 gdev->dev.of_node = chip->parent->of_node;
542 } else {
543#ifdef CONFIG_OF_GPIO
544 /* If the gpiochip has an assigned OF node this takes precedence */
545 if (chip->of_node)
546 gdev->dev.of_node = chip->of_node;
547#endif
548 }
549 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
550 if (gdev->id < 0) {
551 status = gdev->id;
552 goto err_free_gdev;
553 }
554 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
555 device_initialize(&gdev->dev);
556 dev_set_drvdata(&gdev->dev, gdev);
557 if (chip->parent && chip->parent->driver)
558 gdev->owner = chip->parent->driver->owner;
559 else if (chip->owner)
560 /* TODO: remove chip->owner */
561 gdev->owner = chip->owner;
562 else
563 gdev->owner = THIS_MODULE;
564
565 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
566 if (!gdev->descs) {
567 status = -ENOMEM;
568 goto err_free_gdev;
569 }
570
571 if (chip->ngpio == 0) {
572 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
573 status = -EINVAL;
574 goto err_free_descs;
575 }
576
577 if (chip->label)
578 gdev->label = kstrdup(chip->label, GFP_KERNEL);
579 else
580 gdev->label = kstrdup("unknown", GFP_KERNEL);
581 if (!gdev->label) {
582 status = -ENOMEM;
583 goto err_free_descs;
584 }
585
586 gdev->ngpio = chip->ngpio;
587 gdev->data = data;
588
589 spin_lock_irqsave(&gpio_lock, flags);
590
591 /*
592 * TODO: this allocates a Linux GPIO number base in the global
593 * GPIO numberspace for this chip. In the long run we want to
594 * get *rid* of this numberspace and use only descriptors, but
595 * it may be a pipe dream. It will not happen before we get rid
596 * of the sysfs interface anyways.
597 */
598 if (base < 0) {
599 base = gpiochip_find_base(chip->ngpio);
600 if (base < 0) {
601 status = base;
602 spin_unlock_irqrestore(&gpio_lock, flags);
603 goto err_free_label;
604 }
605 /*
606 * TODO: it should not be necessary to reflect the assigned
607 * base outside of the GPIO subsystem. Go over drivers and
608 * see if anyone makes use of this, else drop this and assign
609 * a poison instead.
610 */
611 chip->base = base;
612 }
613 gdev->base = base;
614
615 status = gpiodev_add_to_list(gdev);
616 if (status) {
617 spin_unlock_irqrestore(&gpio_lock, flags);
618 goto err_free_label;
619 }
620
621 for (i = 0; i < chip->ngpio; i++) {
622 struct gpio_desc *desc = &gdev->descs[i];
623
624 desc->gdev = gdev;
625
626 /* REVISIT: most hardware initializes GPIOs as inputs (often
627 * with pullups enabled) so power usage is minimized. Linux
628 * code should set the gpio direction first thing; but until
629 * it does, and in case chip->get_direction is not set, we may
630 * expose the wrong direction in sysfs.
631 */
632 desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
633 }
634
635 spin_unlock_irqrestore(&gpio_lock, flags);
636
637#ifdef CONFIG_PINCTRL
638 INIT_LIST_HEAD(&gdev->pin_ranges);
639#endif
640
641 status = gpiochip_set_desc_names(chip);
642 if (status)
643 goto err_remove_from_list;
644
645 status = of_gpiochip_add(chip);
646 if (status)
647 goto err_remove_chip;
648
649 acpi_gpiochip_add(chip);
650
651 /*
652 * By first adding the chardev, and then adding the device,
653 * we get a device node entry in sysfs under
654 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
655 * coldplug of device nodes and other udev business.
656 * We can do this only if gpiolib has been initialized.
657 * Otherwise, defer until later.
658 */
659 if (gpiolib_initialized) {
660 status = gpiochip_setup_dev(gdev);
661 if (status)
662 goto err_remove_chip;
663 }
664 return 0;
665
666err_remove_chip:
667 acpi_gpiochip_remove(chip);
668 gpiochip_free_hogs(chip);
669 of_gpiochip_remove(chip);
670err_remove_from_list:
671 spin_lock_irqsave(&gpio_lock, flags);
672 list_del(&gdev->list);
673 spin_unlock_irqrestore(&gpio_lock, flags);
674err_free_label:
675 kfree(gdev->label);
676err_free_descs:
677 kfree(gdev->descs);
678err_free_gdev:
679 ida_simple_remove(&gpio_ida, gdev->id);
680 /* failures here can mean systems won't boot... */
681 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
682 gdev->base, gdev->base + gdev->ngpio - 1,
683 chip->label ? : "generic");
684 kfree(gdev);
685 return status;
686}
687EXPORT_SYMBOL_GPL(gpiochip_add_data);
688
689/**
690 * gpiochip_get_data() - get per-subdriver data for the chip
691 */
692void *gpiochip_get_data(struct gpio_chip *chip)
693{
694 return chip->gpiodev->data;
695}
696EXPORT_SYMBOL_GPL(gpiochip_get_data);
697
698/**
699 * gpiochip_remove() - unregister a gpio_chip
700 * @chip: the chip to unregister
701 *
702 * A gpio_chip with any GPIOs still requested may not be removed.
703 */
704void gpiochip_remove(struct gpio_chip *chip)
705{
706 struct gpio_device *gdev = chip->gpiodev;
707 struct gpio_desc *desc;
708 unsigned long flags;
709 unsigned i;
710 bool requested = false;
711
712 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
713 gpiochip_sysfs_unregister(gdev);
714 /* Numb the device, cancelling all outstanding operations */
715 gdev->chip = NULL;
716 gpiochip_irqchip_remove(chip);
717 acpi_gpiochip_remove(chip);
718 gpiochip_remove_pin_ranges(chip);
719 gpiochip_free_hogs(chip);
720 of_gpiochip_remove(chip);
721 /*
722 * We accept no more calls into the driver from this point, so
723 * NULL the driver data pointer
724 */
725 gdev->data = NULL;
726
727 spin_lock_irqsave(&gpio_lock, flags);
728 for (i = 0; i < gdev->ngpio; i++) {
729 desc = &gdev->descs[i];
730 if (test_bit(FLAG_REQUESTED, &desc->flags))
731 requested = true;
732 }
733 spin_unlock_irqrestore(&gpio_lock, flags);
734
735 if (requested)
736 dev_crit(&gdev->dev,
737 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
738
739 /*
740 * The gpiochip side puts its use of the device to rest here:
741 * if there are no userspace clients, the chardev and device will
742 * be removed, else it will be dangling until the last user is
743 * gone.
744 */
745 put_device(&gdev->dev);
746}
747EXPORT_SYMBOL_GPL(gpiochip_remove);
748
749static void devm_gpio_chip_release(struct device *dev, void *res)
750{
751 struct gpio_chip *chip = *(struct gpio_chip **)res;
752
753 gpiochip_remove(chip);
754}
755
756static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
757
758{
759 struct gpio_chip **r = res;
760
761 if (!r || !*r) {
762 WARN_ON(!r || !*r);
763 return 0;
764 }
765
766 return *r == data;
767}
768
769/**
770 * devm_gpiochip_add_data() - Resource manager piochip_add_data()
771 * @dev: the device pointer on which irq_chip belongs to.
772 * @chip: the chip to register, with chip->base initialized
773 * Context: potentially before irqs will work
774 *
775 * Returns a negative errno if the chip can't be registered, such as
776 * because the chip->base is invalid or already associated with a
777 * different chip. Otherwise it returns zero as a success code.
778 *
779 * The gpio chip automatically be released when the device is unbound.
780 */
781int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
782 void *data)
783{
784 struct gpio_chip **ptr;
785 int ret;
786
787 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
788 GFP_KERNEL);
789 if (!ptr)
790 return -ENOMEM;
791
792 ret = gpiochip_add_data(chip, data);
793 if (ret < 0) {
794 devres_free(ptr);
795 return ret;
796 }
797
798 *ptr = chip;
799 devres_add(dev, ptr);
800
801 return 0;
802}
803EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
804
805/**
806 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
807 * @dev: device for which which resource was allocated
808 * @chip: the chip to remove
809 *
810 * A gpio_chip with any GPIOs still requested may not be removed.
811 */
812void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
813{
814 int ret;
815
816 ret = devres_release(dev, devm_gpio_chip_release,
817 devm_gpio_chip_match, chip);
818 if (!ret)
819 WARN_ON(ret);
820}
821EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
822
823/**
824 * gpiochip_find() - iterator for locating a specific gpio_chip
825 * @data: data to pass to match function
826 * @callback: Callback function to check gpio_chip
827 *
828 * Similar to bus_find_device. It returns a reference to a gpio_chip as
829 * determined by a user supplied @match callback. The callback should return
830 * 0 if the device doesn't match and non-zero if it does. If the callback is
831 * non-zero, this function will return to the caller and not iterate over any
832 * more gpio_chips.
833 */
834struct gpio_chip *gpiochip_find(void *data,
835 int (*match)(struct gpio_chip *chip,
836 void *data))
837{
838 struct gpio_device *gdev;
839 struct gpio_chip *chip;
840 unsigned long flags;
841
842 spin_lock_irqsave(&gpio_lock, flags);
843 list_for_each_entry(gdev, &gpio_devices, list)
844 if (match(gdev->chip, data))
845 break;
846
847 /* No match? */
848 if (&gdev->list == &gpio_devices)
849 chip = NULL;
850 else
851 chip = gdev->chip;
852
853 spin_unlock_irqrestore(&gpio_lock, flags);
854
855 return chip;
856}
857EXPORT_SYMBOL_GPL(gpiochip_find);
858
859static int gpiochip_match_name(struct gpio_chip *chip, void *data)
860{
861 const char *name = data;
862
863 return !strcmp(chip->label, name);
864}
865
866static struct gpio_chip *find_chip_by_name(const char *name)
867{
868 return gpiochip_find((void *)name, gpiochip_match_name);
869}
870
871#ifdef CONFIG_GPIOLIB_IRQCHIP
872
873/*
874 * The following is irqchip helper code for gpiochips.
875 */
876
877/**
878 * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
879 * @gpiochip: the gpiochip to set the irqchip chain to
880 * @irqchip: the irqchip to chain to the gpiochip
881 * @parent_irq: the irq number corresponding to the parent IRQ for this
882 * chained irqchip
883 * @parent_handler: the parent interrupt handler for the accumulated IRQ
884 * coming out of the gpiochip. If the interrupt is nested rather than
885 * cascaded, pass NULL in this handler argument
886 */
887void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
888 struct irq_chip *irqchip,
889 int parent_irq,
890 irq_flow_handler_t parent_handler)
891{
892 unsigned int offset;
893
894 if (!gpiochip->irqdomain) {
895 chip_err(gpiochip, "called %s before setting up irqchip\n",
896 __func__);
897 return;
898 }
899
900 if (parent_handler) {
901 if (gpiochip->can_sleep) {
902 chip_err(gpiochip,
903 "you cannot have chained interrupts on a "
904 "chip that may sleep\n");
905 return;
906 }
907 /*
908 * The parent irqchip is already using the chip_data for this
909 * irqchip, so our callbacks simply use the handler_data.
910 */
911 irq_set_chained_handler_and_data(parent_irq, parent_handler,
912 gpiochip);
913
914 gpiochip->irq_parent = parent_irq;
915 }
916
917 /* Set the parent IRQ for all affected IRQs */
918 for (offset = 0; offset < gpiochip->ngpio; offset++)
919 irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
920 parent_irq);
921}
922EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
923
924/**
925 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
926 * @d: the irqdomain used by this irqchip
927 * @irq: the global irq number used by this GPIO irqchip irq
928 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
929 *
930 * This function will set up the mapping for a certain IRQ line on a
931 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
932 * stored inside the gpiochip.
933 */
934static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
935 irq_hw_number_t hwirq)
936{
937 struct gpio_chip *chip = d->host_data;
938
939 irq_set_chip_data(irq, chip);
940 /*
941 * This lock class tells lockdep that GPIO irqs are in a different
942 * category than their parents, so it won't report false recursion.
943 */
944 irq_set_lockdep_class(irq, chip->lock_key);
945 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
946 /* Chips that can sleep need nested thread handlers */
947 if (chip->can_sleep && !chip->irq_not_threaded)
948 irq_set_nested_thread(irq, 1);
949 irq_set_noprobe(irq);
950
951 /*
952 * No set-up of the hardware will happen if IRQ_TYPE_NONE
953 * is passed as default type.
954 */
955 if (chip->irq_default_type != IRQ_TYPE_NONE)
956 irq_set_irq_type(irq, chip->irq_default_type);
957
958 return 0;
959}
960
961static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
962{
963 struct gpio_chip *chip = d->host_data;
964
965 if (chip->can_sleep)
966 irq_set_nested_thread(irq, 0);
967 irq_set_chip_and_handler(irq, NULL, NULL);
968 irq_set_chip_data(irq, NULL);
969}
970
971static const struct irq_domain_ops gpiochip_domain_ops = {
972 .map = gpiochip_irq_map,
973 .unmap = gpiochip_irq_unmap,
974 /* Virtually all GPIO irqchips are twocell:ed */
975 .xlate = irq_domain_xlate_twocell,
976};
977
978static int gpiochip_irq_reqres(struct irq_data *d)
979{
980 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
981
982 if (!try_module_get(chip->gpiodev->owner))
983 return -ENODEV;
984
985 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
986 chip_err(chip,
987 "unable to lock HW IRQ %lu for IRQ\n",
988 d->hwirq);
989 module_put(chip->gpiodev->owner);
990 return -EINVAL;
991 }
992 return 0;
993}
994
995static void gpiochip_irq_relres(struct irq_data *d)
996{
997 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
998
999 gpiochip_unlock_as_irq(chip, d->hwirq);
1000 module_put(chip->gpiodev->owner);
1001}
1002
1003static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1004{
1005 return irq_find_mapping(chip->irqdomain, offset);
1006}
1007
1008/**
1009 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1010 * @gpiochip: the gpiochip to remove the irqchip from
1011 *
1012 * This is called only from gpiochip_remove()
1013 */
1014static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1015{
1016 unsigned int offset;
1017
1018 acpi_gpiochip_free_interrupts(gpiochip);
1019
1020 if (gpiochip->irq_parent) {
1021 irq_set_chained_handler(gpiochip->irq_parent, NULL);
1022 irq_set_handler_data(gpiochip->irq_parent, NULL);
1023 }
1024
1025 /* Remove all IRQ mappings and delete the domain */
1026 if (gpiochip->irqdomain) {
1027 for (offset = 0; offset < gpiochip->ngpio; offset++)
1028 irq_dispose_mapping(
1029 irq_find_mapping(gpiochip->irqdomain, offset));
1030 irq_domain_remove(gpiochip->irqdomain);
1031 }
1032
1033 if (gpiochip->irqchip) {
1034 gpiochip->irqchip->irq_request_resources = NULL;
1035 gpiochip->irqchip->irq_release_resources = NULL;
1036 gpiochip->irqchip = NULL;
1037 }
1038}
1039
1040/**
1041 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
1042 * @gpiochip: the gpiochip to add the irqchip to
1043 * @irqchip: the irqchip to add to the gpiochip
1044 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1045 * allocate gpiochip irqs from
1046 * @handler: the irq handler to use (often a predefined irq core function)
1047 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1048 * to have the core avoid setting up any default type in the hardware.
1049 * @lock_key: lockdep class
1050 *
1051 * This function closely associates a certain irqchip with a certain
1052 * gpiochip, providing an irq domain to translate the local IRQs to
1053 * global irqs in the gpiolib core, and making sure that the gpiochip
1054 * is passed as chip data to all related functions. Driver callbacks
1055 * need to use gpiochip_get_data() to get their local state containers back
1056 * from the gpiochip passed as chip data. An irqdomain will be stored
1057 * in the gpiochip that shall be used by the driver to handle IRQ number
1058 * translation. The gpiochip will need to be initialized and registered
1059 * before calling this function.
1060 *
1061 * This function will handle two cell:ed simple IRQs and assumes all
1062 * the pins on the gpiochip can generate a unique IRQ. Everything else
1063 * need to be open coded.
1064 */
1065int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
1066 struct irq_chip *irqchip,
1067 unsigned int first_irq,
1068 irq_flow_handler_t handler,
1069 unsigned int type,
1070 struct lock_class_key *lock_key)
1071{
1072 struct device_node *of_node;
1073 unsigned int offset;
1074 unsigned irq_base = 0;
1075
1076 if (!gpiochip || !irqchip)
1077 return -EINVAL;
1078
1079 if (!gpiochip->parent) {
1080 pr_err("missing gpiochip .dev parent pointer\n");
1081 return -EINVAL;
1082 }
1083 of_node = gpiochip->parent->of_node;
1084#ifdef CONFIG_OF_GPIO
1085 /*
1086 * If the gpiochip has an assigned OF node this takes precedence
1087 * FIXME: get rid of this and use gpiochip->parent->of_node
1088 * everywhere
1089 */
1090 if (gpiochip->of_node)
1091 of_node = gpiochip->of_node;
1092#endif
1093 gpiochip->irqchip = irqchip;
1094 gpiochip->irq_handler = handler;
1095 gpiochip->irq_default_type = type;
1096 gpiochip->to_irq = gpiochip_to_irq;
1097 gpiochip->lock_key = lock_key;
1098 gpiochip->irqdomain = irq_domain_add_simple(of_node,
1099 gpiochip->ngpio, first_irq,
1100 &gpiochip_domain_ops, gpiochip);
1101 if (!gpiochip->irqdomain) {
1102 gpiochip->irqchip = NULL;
1103 return -EINVAL;
1104 }
1105
1106 /*
1107 * It is possible for a driver to override this, but only if the
1108 * alternative functions are both implemented.
1109 */
1110 if (!irqchip->irq_request_resources &&
1111 !irqchip->irq_release_resources) {
1112 irqchip->irq_request_resources = gpiochip_irq_reqres;
1113 irqchip->irq_release_resources = gpiochip_irq_relres;
1114 }
1115
1116 /*
1117 * Prepare the mapping since the irqchip shall be orthogonal to
1118 * any gpiochip calls. If the first_irq was zero, this is
1119 * necessary to allocate descriptors for all IRQs.
1120 */
1121 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1122 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
1123 if (offset == 0)
1124 /*
1125 * Store the base into the gpiochip to be used when
1126 * unmapping the irqs.
1127 */
1128 gpiochip->irq_base = irq_base;
1129 }
1130
1131 acpi_gpiochip_request_interrupts(gpiochip);
1132
1133 return 0;
1134}
1135EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add);
1136
1137#else /* CONFIG_GPIOLIB_IRQCHIP */
1138
1139static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
1140
1141#endif /* CONFIG_GPIOLIB_IRQCHIP */
1142
1143/**
1144 * gpiochip_generic_request() - request the gpio function for a pin
1145 * @chip: the gpiochip owning the GPIO
1146 * @offset: the offset of the GPIO to request for GPIO function
1147 */
1148int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
1149{
1150 return pinctrl_request_gpio(chip->gpiodev->base + offset);
1151}
1152EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1153
1154/**
1155 * gpiochip_generic_free() - free the gpio function from a pin
1156 * @chip: the gpiochip to request the gpio function for
1157 * @offset: the offset of the GPIO to free from GPIO function
1158 */
1159void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
1160{
1161 pinctrl_free_gpio(chip->gpiodev->base + offset);
1162}
1163EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1164
1165#ifdef CONFIG_PINCTRL
1166
1167/**
1168 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1169 * @chip: the gpiochip to add the range for
1170 * @pctldev: the pin controller to map to
1171 * @gpio_offset: the start offset in the current gpio_chip number space
1172 * @pin_group: name of the pin group inside the pin controller
1173 */
1174int gpiochip_add_pingroup_range(struct gpio_chip *chip,
1175 struct pinctrl_dev *pctldev,
1176 unsigned int gpio_offset, const char *pin_group)
1177{
1178 struct gpio_pin_range *pin_range;
1179 struct gpio_device *gdev = chip->gpiodev;
1180 int ret;
1181
1182 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1183 if (!pin_range) {
1184 chip_err(chip, "failed to allocate pin ranges\n");
1185 return -ENOMEM;
1186 }
1187
1188 /* Use local offset as range ID */
1189 pin_range->range.id = gpio_offset;
1190 pin_range->range.gc = chip;
1191 pin_range->range.name = chip->label;
1192 pin_range->range.base = gdev->base + gpio_offset;
1193 pin_range->pctldev = pctldev;
1194
1195 ret = pinctrl_get_group_pins(pctldev, pin_group,
1196 &pin_range->range.pins,
1197 &pin_range->range.npins);
1198 if (ret < 0) {
1199 kfree(pin_range);
1200 return ret;
1201 }
1202
1203 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1204
1205 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1206 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1207 pinctrl_dev_get_devname(pctldev), pin_group);
1208
1209 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1210
1211 return 0;
1212}
1213EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1214
1215/**
1216 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1217 * @chip: the gpiochip to add the range for
1218 * @pinctrl_name: the dev_name() of the pin controller to map to
1219 * @gpio_offset: the start offset in the current gpio_chip number space
1220 * @pin_offset: the start offset in the pin controller number space
1221 * @npins: the number of pins from the offset of each pin space (GPIO and
1222 * pin controller) to accumulate in this range
1223 */
1224int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
1225 unsigned int gpio_offset, unsigned int pin_offset,
1226 unsigned int npins)
1227{
1228 struct gpio_pin_range *pin_range;
1229 struct gpio_device *gdev = chip->gpiodev;
1230 int ret;
1231
1232 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1233 if (!pin_range) {
1234 chip_err(chip, "failed to allocate pin ranges\n");
1235 return -ENOMEM;
1236 }
1237
1238 /* Use local offset as range ID */
1239 pin_range->range.id = gpio_offset;
1240 pin_range->range.gc = chip;
1241 pin_range->range.name = chip->label;
1242 pin_range->range.base = gdev->base + gpio_offset;
1243 pin_range->range.pin_base = pin_offset;
1244 pin_range->range.npins = npins;
1245 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1246 &pin_range->range);
1247 if (IS_ERR(pin_range->pctldev)) {
1248 ret = PTR_ERR(pin_range->pctldev);
1249 chip_err(chip, "could not create pin range\n");
1250 kfree(pin_range);
1251 return ret;
1252 }
1253 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1254 gpio_offset, gpio_offset + npins - 1,
1255 pinctl_name,
1256 pin_offset, pin_offset + npins - 1);
1257
1258 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1259
1260 return 0;
1261}
1262EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1263
1264/**
1265 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1266 * @chip: the chip to remove all the mappings for
1267 */
1268void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
1269{
1270 struct gpio_pin_range *pin_range, *tmp;
1271 struct gpio_device *gdev = chip->gpiodev;
1272
1273 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1274 list_del(&pin_range->node);
1275 pinctrl_remove_gpio_range(pin_range->pctldev,
1276 &pin_range->range);
1277 kfree(pin_range);
1278 }
1279}
1280EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1281
1282#endif /* CONFIG_PINCTRL */
1283
1284/* These "optional" allocation calls help prevent drivers from stomping
1285 * on each other, and help provide better diagnostics in debugfs.
1286 * They're called even less than the "set direction" calls.
1287 */
1288static int __gpiod_request(struct gpio_desc *desc, const char *label)
1289{
1290 struct gpio_chip *chip = desc->gdev->chip;
1291 int status;
1292 unsigned long flags;
1293
1294 spin_lock_irqsave(&gpio_lock, flags);
1295
1296 /* NOTE: gpio_request() can be called in early boot,
1297 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1298 */
1299
1300 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1301 desc_set_label(desc, label ? : "?");
1302 status = 0;
1303 } else {
1304 status = -EBUSY;
1305 goto done;
1306 }
1307
1308 if (chip->request) {
1309 /* chip->request may sleep */
1310 spin_unlock_irqrestore(&gpio_lock, flags);
1311 status = chip->request(chip, gpio_chip_hwgpio(desc));
1312 spin_lock_irqsave(&gpio_lock, flags);
1313
1314 if (status < 0) {
1315 desc_set_label(desc, NULL);
1316 clear_bit(FLAG_REQUESTED, &desc->flags);
1317 goto done;
1318 }
1319 }
1320 if (chip->get_direction) {
1321 /* chip->get_direction may sleep */
1322 spin_unlock_irqrestore(&gpio_lock, flags);
1323 gpiod_get_direction(desc);
1324 spin_lock_irqsave(&gpio_lock, flags);
1325 }
1326done:
1327 if (status < 0) {
1328 /* Clear flags that might have been set by the caller before
1329 * requesting the GPIO.
1330 */
1331 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
1332 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
1333 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
1334 }
1335 spin_unlock_irqrestore(&gpio_lock, flags);
1336 return status;
1337}
1338
1339/*
1340 * This descriptor validation needs to be inserted verbatim into each
1341 * function taking a descriptor, so we need to use a preprocessor
1342 * macro to avoid endless duplication.
1343 */
1344#define VALIDATE_DESC(desc) do { \
1345 if (!desc || !desc->gdev) { \
1346 pr_warn("%s: invalid GPIO\n", __func__); \
1347 return -EINVAL; \
1348 } \
1349 if ( !desc->gdev->chip ) { \
1350 dev_warn(&desc->gdev->dev, \
1351 "%s: backing chip is gone\n", __func__); \
1352 return 0; \
1353 } } while (0)
1354
1355#define VALIDATE_DESC_VOID(desc) do { \
1356 if (!desc || !desc->gdev) { \
1357 pr_warn("%s: invalid GPIO\n", __func__); \
1358 return; \
1359 } \
1360 if (!desc->gdev->chip) { \
1361 dev_warn(&desc->gdev->dev, \
1362 "%s: backing chip is gone\n", __func__); \
1363 return; \
1364 } } while (0)
1365
1366
1367int gpiod_request(struct gpio_desc *desc, const char *label)
1368{
1369 int status = -EPROBE_DEFER;
1370 struct gpio_device *gdev;
1371
1372 VALIDATE_DESC(desc);
1373 gdev = desc->gdev;
1374
1375 if (try_module_get(gdev->owner)) {
1376 status = __gpiod_request(desc, label);
1377 if (status < 0)
1378 module_put(gdev->owner);
1379 else
1380 get_device(&gdev->dev);
1381 }
1382
1383 if (status)
1384 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
1385
1386 return status;
1387}
1388
1389static bool __gpiod_free(struct gpio_desc *desc)
1390{
1391 bool ret = false;
1392 unsigned long flags;
1393 struct gpio_chip *chip;
1394
1395 might_sleep();
1396
1397 gpiod_unexport(desc);
1398
1399 spin_lock_irqsave(&gpio_lock, flags);
1400
1401 chip = desc->gdev->chip;
1402 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
1403 if (chip->free) {
1404 spin_unlock_irqrestore(&gpio_lock, flags);
1405 might_sleep_if(chip->can_sleep);
1406 chip->free(chip, gpio_chip_hwgpio(desc));
1407 spin_lock_irqsave(&gpio_lock, flags);
1408 }
1409 desc_set_label(desc, NULL);
1410 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
1411 clear_bit(FLAG_REQUESTED, &desc->flags);
1412 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
1413 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
1414 clear_bit(FLAG_IS_HOGGED, &desc->flags);
1415 ret = true;
1416 }
1417
1418 spin_unlock_irqrestore(&gpio_lock, flags);
1419 return ret;
1420}
1421
1422void gpiod_free(struct gpio_desc *desc)
1423{
1424 if (desc && desc->gdev && __gpiod_free(desc)) {
1425 module_put(desc->gdev->owner);
1426 put_device(&desc->gdev->dev);
1427 } else {
1428 WARN_ON(extra_checks);
1429 }
1430}
1431
1432/**
1433 * gpiochip_is_requested - return string iff signal was requested
1434 * @chip: controller managing the signal
1435 * @offset: of signal within controller's 0..(ngpio - 1) range
1436 *
1437 * Returns NULL if the GPIO is not currently requested, else a string.
1438 * The string returned is the label passed to gpio_request(); if none has been
1439 * passed it is a meaningless, non-NULL constant.
1440 *
1441 * This function is for use by GPIO controller drivers. The label can
1442 * help with diagnostics, and knowing that the signal is used as a GPIO
1443 * can help avoid accidentally multiplexing it to another controller.
1444 */
1445const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
1446{
1447 struct gpio_desc *desc;
1448
1449 if (offset >= chip->ngpio)
1450 return NULL;
1451
1452 desc = &chip->gpiodev->descs[offset];
1453
1454 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
1455 return NULL;
1456 return desc->label;
1457}
1458EXPORT_SYMBOL_GPL(gpiochip_is_requested);
1459
1460/**
1461 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
1462 * @desc: GPIO descriptor to request
1463 * @label: label for the GPIO
1464 *
1465 * Function allows GPIO chip drivers to request and use their own GPIO
1466 * descriptors via gpiolib API. Difference to gpiod_request() is that this
1467 * function will not increase reference count of the GPIO chip module. This
1468 * allows the GPIO chip module to be unloaded as needed (we assume that the
1469 * GPIO chip driver handles freeing the GPIOs it has requested).
1470 */
1471struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
1472 const char *label)
1473{
1474 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
1475 int err;
1476
1477 if (IS_ERR(desc)) {
1478 chip_err(chip, "failed to get GPIO descriptor\n");
1479 return desc;
1480 }
1481
1482 err = __gpiod_request(desc, label);
1483 if (err < 0)
1484 return ERR_PTR(err);
1485
1486 return desc;
1487}
1488EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
1489
1490/**
1491 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
1492 * @desc: GPIO descriptor to free
1493 *
1494 * Function frees the given GPIO requested previously with
1495 * gpiochip_request_own_desc().
1496 */
1497void gpiochip_free_own_desc(struct gpio_desc *desc)
1498{
1499 if (desc)
1500 __gpiod_free(desc);
1501}
1502EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
1503
1504/*
1505 * Drivers MUST set GPIO direction before making get/set calls. In
1506 * some cases this is done in early boot, before IRQs are enabled.
1507 *
1508 * As a rule these aren't called more than once (except for drivers
1509 * using the open-drain emulation idiom) so these are natural places
1510 * to accumulate extra debugging checks. Note that we can't (yet)
1511 * rely on gpio_request() having been called beforehand.
1512 */
1513
1514/**
1515 * gpiod_direction_input - set the GPIO direction to input
1516 * @desc: GPIO to set to input
1517 *
1518 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
1519 * be called safely on it.
1520 *
1521 * Return 0 in case of success, else an error code.
1522 */
1523int gpiod_direction_input(struct gpio_desc *desc)
1524{
1525 struct gpio_chip *chip;
1526 int status = -EINVAL;
1527
1528 VALIDATE_DESC(desc);
1529 chip = desc->gdev->chip;
1530
1531 if (!chip->get || !chip->direction_input) {
1532 gpiod_warn(desc,
1533 "%s: missing get() or direction_input() operations\n",
1534 __func__);
1535 return -EIO;
1536 }
1537
1538 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
1539 if (status == 0)
1540 clear_bit(FLAG_IS_OUT, &desc->flags);
1541
1542 trace_gpio_direction(desc_to_gpio(desc), 1, status);
1543
1544 return status;
1545}
1546EXPORT_SYMBOL_GPL(gpiod_direction_input);
1547
1548static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1549{
1550 struct gpio_chip *chip;
1551 int status = -EINVAL;
1552
1553 /* GPIOs used for IRQs shall not be set as output */
1554 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
1555 gpiod_err(desc,
1556 "%s: tried to set a GPIO tied to an IRQ as output\n",
1557 __func__);
1558 return -EIO;
1559 }
1560
1561 /* Open drain pin should not be driven to 1 */
1562 if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1563 return gpiod_direction_input(desc);
1564
1565 /* Open source pin should not be driven to 0 */
1566 if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1567 return gpiod_direction_input(desc);
1568
1569 chip = desc->gdev->chip;
1570 if (!chip->set || !chip->direction_output) {
1571 gpiod_warn(desc,
1572 "%s: missing set() or direction_output() operations\n",
1573 __func__);
1574 return -EIO;
1575 }
1576
1577 status = chip->direction_output(chip, gpio_chip_hwgpio(desc), value);
1578 if (status == 0)
1579 set_bit(FLAG_IS_OUT, &desc->flags);
1580 trace_gpio_value(desc_to_gpio(desc), 0, value);
1581 trace_gpio_direction(desc_to_gpio(desc), 0, status);
1582 return status;
1583}
1584
1585/**
1586 * gpiod_direction_output_raw - set the GPIO direction to output
1587 * @desc: GPIO to set to output
1588 * @value: initial output value of the GPIO
1589 *
1590 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1591 * be called safely on it. The initial value of the output must be specified
1592 * as raw value on the physical line without regard for the ACTIVE_LOW status.
1593 *
1594 * Return 0 in case of success, else an error code.
1595 */
1596int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1597{
1598 VALIDATE_DESC(desc);
1599 return _gpiod_direction_output_raw(desc, value);
1600}
1601EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
1602
1603/**
1604 * gpiod_direction_output - set the GPIO direction to output
1605 * @desc: GPIO to set to output
1606 * @value: initial output value of the GPIO
1607 *
1608 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1609 * be called safely on it. The initial value of the output must be specified
1610 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1611 * account.
1612 *
1613 * Return 0 in case of success, else an error code.
1614 */
1615int gpiod_direction_output(struct gpio_desc *desc, int value)
1616{
1617 VALIDATE_DESC(desc);
1618 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1619 value = !value;
1620 return _gpiod_direction_output_raw(desc, value);
1621}
1622EXPORT_SYMBOL_GPL(gpiod_direction_output);
1623
1624/**
1625 * gpiod_set_debounce - sets @debounce time for a @gpio
1626 * @gpio: the gpio to set debounce time
1627 * @debounce: debounce time is microseconds
1628 *
1629 * returns -ENOTSUPP if the controller does not support setting
1630 * debounce.
1631 */
1632int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
1633{
1634 struct gpio_chip *chip;
1635
1636 VALIDATE_DESC(desc);
1637 chip = desc->gdev->chip;
1638 if (!chip->set || !chip->set_debounce) {
1639 gpiod_dbg(desc,
1640 "%s: missing set() or set_debounce() operations\n",
1641 __func__);
1642 return -ENOTSUPP;
1643 }
1644
1645 return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);
1646}
1647EXPORT_SYMBOL_GPL(gpiod_set_debounce);
1648
1649/**
1650 * gpiod_is_active_low - test whether a GPIO is active-low or not
1651 * @desc: the gpio descriptor to test
1652 *
1653 * Returns 1 if the GPIO is active-low, 0 otherwise.
1654 */
1655int gpiod_is_active_low(const struct gpio_desc *desc)
1656{
1657 VALIDATE_DESC(desc);
1658 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
1659}
1660EXPORT_SYMBOL_GPL(gpiod_is_active_low);
1661
1662/* I/O calls are only valid after configuration completed; the relevant
1663 * "is this a valid GPIO" error checks should already have been done.
1664 *
1665 * "Get" operations are often inlinable as reading a pin value register,
1666 * and masking the relevant bit in that register.
1667 *
1668 * When "set" operations are inlinable, they involve writing that mask to
1669 * one register to set a low value, or a different register to set it high.
1670 * Otherwise locking is needed, so there may be little value to inlining.
1671 *
1672 *------------------------------------------------------------------------
1673 *
1674 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
1675 * have requested the GPIO. That can include implicit requesting by
1676 * a direction setting call. Marking a gpio as requested locks its chip
1677 * in memory, guaranteeing that these table lookups need no more locking
1678 * and that gpiochip_remove() will fail.
1679 *
1680 * REVISIT when debugging, consider adding some instrumentation to ensure
1681 * that the GPIO was actually requested.
1682 */
1683
1684static int _gpiod_get_raw_value(const struct gpio_desc *desc)
1685{
1686 struct gpio_chip *chip;
1687 int offset;
1688 int value;
1689
1690 chip = desc->gdev->chip;
1691 offset = gpio_chip_hwgpio(desc);
1692 value = chip->get ? chip->get(chip, offset) : -EIO;
1693 value = value < 0 ? value : !!value;
1694 trace_gpio_value(desc_to_gpio(desc), 1, value);
1695 return value;
1696}
1697
1698/**
1699 * gpiod_get_raw_value() - return a gpio's raw value
1700 * @desc: gpio whose value will be returned
1701 *
1702 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1703 * its ACTIVE_LOW status, or negative errno on failure.
1704 *
1705 * This function should be called from contexts where we cannot sleep, and will
1706 * complain if the GPIO chip functions potentially sleep.
1707 */
1708int gpiod_get_raw_value(const struct gpio_desc *desc)
1709{
1710 VALIDATE_DESC(desc);
1711 /* Should be using gpio_get_value_cansleep() */
1712 WARN_ON(desc->gdev->chip->can_sleep);
1713 return _gpiod_get_raw_value(desc);
1714}
1715EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
1716
1717/**
1718 * gpiod_get_value() - return a gpio's value
1719 * @desc: gpio whose value will be returned
1720 *
1721 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1722 * account, or negative errno on failure.
1723 *
1724 * This function should be called from contexts where we cannot sleep, and will
1725 * complain if the GPIO chip functions potentially sleep.
1726 */
1727int gpiod_get_value(const struct gpio_desc *desc)
1728{
1729 int value;
1730
1731 VALIDATE_DESC(desc);
1732 /* Should be using gpio_get_value_cansleep() */
1733 WARN_ON(desc->gdev->chip->can_sleep);
1734
1735 value = _gpiod_get_raw_value(desc);
1736 if (value < 0)
1737 return value;
1738
1739 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1740 value = !value;
1741
1742 return value;
1743}
1744EXPORT_SYMBOL_GPL(gpiod_get_value);
1745
1746/*
1747 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
1748 * @desc: gpio descriptor whose state need to be set.
1749 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1750 */
1751static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
1752{
1753 int err = 0;
1754 struct gpio_chip *chip = desc->gdev->chip;
1755 int offset = gpio_chip_hwgpio(desc);
1756
1757 if (value) {
1758 err = chip->direction_input(chip, offset);
1759 if (!err)
1760 clear_bit(FLAG_IS_OUT, &desc->flags);
1761 } else {
1762 err = chip->direction_output(chip, offset, 0);
1763 if (!err)
1764 set_bit(FLAG_IS_OUT, &desc->flags);
1765 }
1766 trace_gpio_direction(desc_to_gpio(desc), value, err);
1767 if (err < 0)
1768 gpiod_err(desc,
1769 "%s: Error in set_value for open drain err %d\n",
1770 __func__, err);
1771}
1772
1773/*
1774 * _gpio_set_open_source_value() - Set the open source gpio's value.
1775 * @desc: gpio descriptor whose state need to be set.
1776 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1777 */
1778static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
1779{
1780 int err = 0;
1781 struct gpio_chip *chip = desc->gdev->chip;
1782 int offset = gpio_chip_hwgpio(desc);
1783
1784 if (value) {
1785 err = chip->direction_output(chip, offset, 1);
1786 if (!err)
1787 set_bit(FLAG_IS_OUT, &desc->flags);
1788 } else {
1789 err = chip->direction_input(chip, offset);
1790 if (!err)
1791 clear_bit(FLAG_IS_OUT, &desc->flags);
1792 }
1793 trace_gpio_direction(desc_to_gpio(desc), !value, err);
1794 if (err < 0)
1795 gpiod_err(desc,
1796 "%s: Error in set_value for open source err %d\n",
1797 __func__, err);
1798}
1799
1800static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
1801{
1802 struct gpio_chip *chip;
1803
1804 chip = desc->gdev->chip;
1805 trace_gpio_value(desc_to_gpio(desc), 0, value);
1806 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1807 _gpio_set_open_drain_value(desc, value);
1808 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1809 _gpio_set_open_source_value(desc, value);
1810 else
1811 chip->set(chip, gpio_chip_hwgpio(desc), value);
1812}
1813
1814/*
1815 * set multiple outputs on the same chip;
1816 * use the chip's set_multiple function if available;
1817 * otherwise set the outputs sequentially;
1818 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
1819 * defines which outputs are to be changed
1820 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
1821 * defines the values the outputs specified by mask are to be set to
1822 */
1823static void gpio_chip_set_multiple(struct gpio_chip *chip,
1824 unsigned long *mask, unsigned long *bits)
1825{
1826 if (chip->set_multiple) {
1827 chip->set_multiple(chip, mask, bits);
1828 } else {
1829 int i;
1830 for (i = 0; i < chip->ngpio; i++) {
1831 if (mask[BIT_WORD(i)] == 0) {
1832 /* no more set bits in this mask word;
1833 * skip ahead to the next word */
1834 i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1;
1835 continue;
1836 }
1837 /* set outputs if the corresponding mask bit is set */
1838 if (__test_and_clear_bit(i, mask))
1839 chip->set(chip, i, test_bit(i, bits));
1840 }
1841 }
1842}
1843
1844static void gpiod_set_array_value_priv(bool raw, bool can_sleep,
1845 unsigned int array_size,
1846 struct gpio_desc **desc_array,
1847 int *value_array)
1848{
1849 int i = 0;
1850
1851 while (i < array_size) {
1852 struct gpio_chip *chip = desc_array[i]->gdev->chip;
1853 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
1854 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
1855 int count = 0;
1856
1857 if (!can_sleep)
1858 WARN_ON(chip->can_sleep);
1859
1860 memset(mask, 0, sizeof(mask));
1861 do {
1862 struct gpio_desc *desc = desc_array[i];
1863 int hwgpio = gpio_chip_hwgpio(desc);
1864 int value = value_array[i];
1865
1866 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1867 value = !value;
1868 trace_gpio_value(desc_to_gpio(desc), 0, value);
1869 /*
1870 * collect all normal outputs belonging to the same chip
1871 * open drain and open source outputs are set individually
1872 */
1873 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
1874 _gpio_set_open_drain_value(desc, value);
1875 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
1876 _gpio_set_open_source_value(desc, value);
1877 } else {
1878 __set_bit(hwgpio, mask);
1879 if (value)
1880 __set_bit(hwgpio, bits);
1881 else
1882 __clear_bit(hwgpio, bits);
1883 count++;
1884 }
1885 i++;
1886 } while ((i < array_size) &&
1887 (desc_array[i]->gdev->chip == chip));
1888 /* push collected bits to outputs */
1889 if (count != 0)
1890 gpio_chip_set_multiple(chip, mask, bits);
1891 }
1892}
1893
1894/**
1895 * gpiod_set_raw_value() - assign a gpio's raw value
1896 * @desc: gpio whose value will be assigned
1897 * @value: value to assign
1898 *
1899 * Set the raw value of the GPIO, i.e. the value of its physical line without
1900 * regard for its ACTIVE_LOW status.
1901 *
1902 * This function should be called from contexts where we cannot sleep, and will
1903 * complain if the GPIO chip functions potentially sleep.
1904 */
1905void gpiod_set_raw_value(struct gpio_desc *desc, int value)
1906{
1907 VALIDATE_DESC_VOID(desc);
1908 /* Should be using gpiod_set_value_cansleep() */
1909 WARN_ON(desc->gdev->chip->can_sleep);
1910 _gpiod_set_raw_value(desc, value);
1911}
1912EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
1913
1914/**
1915 * gpiod_set_value() - assign a gpio's value
1916 * @desc: gpio whose value will be assigned
1917 * @value: value to assign
1918 *
1919 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1920 * account
1921 *
1922 * This function should be called from contexts where we cannot sleep, and will
1923 * complain if the GPIO chip functions potentially sleep.
1924 */
1925void gpiod_set_value(struct gpio_desc *desc, int value)
1926{
1927 VALIDATE_DESC_VOID(desc);
1928 /* Should be using gpiod_set_value_cansleep() */
1929 WARN_ON(desc->gdev->chip->can_sleep);
1930 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1931 value = !value;
1932 _gpiod_set_raw_value(desc, value);
1933}
1934EXPORT_SYMBOL_GPL(gpiod_set_value);
1935
1936/**
1937 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
1938 * @array_size: number of elements in the descriptor / value arrays
1939 * @desc_array: array of GPIO descriptors whose values will be assigned
1940 * @value_array: array of values to assign
1941 *
1942 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1943 * without regard for their ACTIVE_LOW status.
1944 *
1945 * This function should be called from contexts where we cannot sleep, and will
1946 * complain if the GPIO chip functions potentially sleep.
1947 */
1948void gpiod_set_raw_array_value(unsigned int array_size,
1949 struct gpio_desc **desc_array, int *value_array)
1950{
1951 if (!desc_array)
1952 return;
1953 gpiod_set_array_value_priv(true, false, array_size, desc_array,
1954 value_array);
1955}
1956EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
1957
1958/**
1959 * gpiod_set_array_value() - assign values to an array of GPIOs
1960 * @array_size: number of elements in the descriptor / value arrays
1961 * @desc_array: array of GPIO descriptors whose values will be assigned
1962 * @value_array: array of values to assign
1963 *
1964 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
1965 * into account.
1966 *
1967 * This function should be called from contexts where we cannot sleep, and will
1968 * complain if the GPIO chip functions potentially sleep.
1969 */
1970void gpiod_set_array_value(unsigned int array_size,
1971 struct gpio_desc **desc_array, int *value_array)
1972{
1973 if (!desc_array)
1974 return;
1975 gpiod_set_array_value_priv(false, false, array_size, desc_array,
1976 value_array);
1977}
1978EXPORT_SYMBOL_GPL(gpiod_set_array_value);
1979
1980/**
1981 * gpiod_cansleep() - report whether gpio value access may sleep
1982 * @desc: gpio to check
1983 *
1984 */
1985int gpiod_cansleep(const struct gpio_desc *desc)
1986{
1987 VALIDATE_DESC(desc);
1988 return desc->gdev->chip->can_sleep;
1989}
1990EXPORT_SYMBOL_GPL(gpiod_cansleep);
1991
1992/**
1993 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
1994 * @desc: gpio whose IRQ will be returned (already requested)
1995 *
1996 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
1997 * error.
1998 */
1999int gpiod_to_irq(const struct gpio_desc *desc)
2000{
2001 struct gpio_chip *chip;
2002 int offset;
2003
2004 VALIDATE_DESC(desc);
2005 chip = desc->gdev->chip;
2006 offset = gpio_chip_hwgpio(desc);
2007 return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO;
2008}
2009EXPORT_SYMBOL_GPL(gpiod_to_irq);
2010
2011/**
2012 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
2013 * @chip: the chip the GPIO to lock belongs to
2014 * @offset: the offset of the GPIO to lock as IRQ
2015 *
2016 * This is used directly by GPIO drivers that want to lock down
2017 * a certain GPIO line to be used for IRQs.
2018 */
2019int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
2020{
2021 if (offset >= chip->ngpio)
2022 return -EINVAL;
2023
2024 if (test_bit(FLAG_IS_OUT, &chip->gpiodev->descs[offset].flags)) {
2025 chip_err(chip,
2026 "%s: tried to flag a GPIO set as output for IRQ\n",
2027 __func__);
2028 return -EIO;
2029 }
2030
2031 set_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2032 return 0;
2033}
2034EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
2035
2036/**
2037 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
2038 * @chip: the chip the GPIO to lock belongs to
2039 * @offset: the offset of the GPIO to lock as IRQ
2040 *
2041 * This is used directly by GPIO drivers that want to indicate
2042 * that a certain GPIO is no longer used exclusively for IRQ.
2043 */
2044void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
2045{
2046 if (offset >= chip->ngpio)
2047 return;
2048
2049 clear_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2050}
2051EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
2052
2053bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
2054{
2055 if (offset >= chip->ngpio)
2056 return false;
2057
2058 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2059}
2060EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
2061
2062bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
2063{
2064 if (offset >= chip->ngpio)
2065 return false;
2066
2067 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
2068}
2069EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
2070
2071bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
2072{
2073 if (offset >= chip->ngpio)
2074 return false;
2075
2076 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
2077}
2078EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
2079
2080/**
2081 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2082 * @desc: gpio whose value will be returned
2083 *
2084 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2085 * its ACTIVE_LOW status, or negative errno on failure.
2086 *
2087 * This function is to be called from contexts that can sleep.
2088 */
2089int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
2090{
2091 might_sleep_if(extra_checks);
2092 VALIDATE_DESC(desc);
2093 return _gpiod_get_raw_value(desc);
2094}
2095EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
2096
2097/**
2098 * gpiod_get_value_cansleep() - return a gpio's value
2099 * @desc: gpio whose value will be returned
2100 *
2101 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2102 * account, or negative errno on failure.
2103 *
2104 * This function is to be called from contexts that can sleep.
2105 */
2106int gpiod_get_value_cansleep(const struct gpio_desc *desc)
2107{
2108 int value;
2109
2110 might_sleep_if(extra_checks);
2111 VALIDATE_DESC(desc);
2112 value = _gpiod_get_raw_value(desc);
2113 if (value < 0)
2114 return value;
2115
2116 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2117 value = !value;
2118
2119 return value;
2120}
2121EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
2122
2123/**
2124 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2125 * @desc: gpio whose value will be assigned
2126 * @value: value to assign
2127 *
2128 * Set the raw value of the GPIO, i.e. the value of its physical line without
2129 * regard for its ACTIVE_LOW status.
2130 *
2131 * This function is to be called from contexts that can sleep.
2132 */
2133void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
2134{
2135 might_sleep_if(extra_checks);
2136 VALIDATE_DESC_VOID(desc);
2137 _gpiod_set_raw_value(desc, value);
2138}
2139EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
2140
2141/**
2142 * gpiod_set_value_cansleep() - assign a gpio's value
2143 * @desc: gpio whose value will be assigned
2144 * @value: value to assign
2145 *
2146 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2147 * account
2148 *
2149 * This function is to be called from contexts that can sleep.
2150 */
2151void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
2152{
2153 might_sleep_if(extra_checks);
2154 VALIDATE_DESC_VOID(desc);
2155 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2156 value = !value;
2157 _gpiod_set_raw_value(desc, value);
2158}
2159EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
2160
2161/**
2162 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2163 * @array_size: number of elements in the descriptor / value arrays
2164 * @desc_array: array of GPIO descriptors whose values will be assigned
2165 * @value_array: array of values to assign
2166 *
2167 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2168 * without regard for their ACTIVE_LOW status.
2169 *
2170 * This function is to be called from contexts that can sleep.
2171 */
2172void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
2173 struct gpio_desc **desc_array,
2174 int *value_array)
2175{
2176 might_sleep_if(extra_checks);
2177 if (!desc_array)
2178 return;
2179 gpiod_set_array_value_priv(true, true, array_size, desc_array,
2180 value_array);
2181}
2182EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
2183
2184/**
2185 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2186 * @array_size: number of elements in the descriptor / value arrays
2187 * @desc_array: array of GPIO descriptors whose values will be assigned
2188 * @value_array: array of values to assign
2189 *
2190 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2191 * into account.
2192 *
2193 * This function is to be called from contexts that can sleep.
2194 */
2195void gpiod_set_array_value_cansleep(unsigned int array_size,
2196 struct gpio_desc **desc_array,
2197 int *value_array)
2198{
2199 might_sleep_if(extra_checks);
2200 if (!desc_array)
2201 return;
2202 gpiod_set_array_value_priv(false, true, array_size, desc_array,
2203 value_array);
2204}
2205EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
2206
2207/**
2208 * gpiod_add_lookup_table() - register GPIO device consumers
2209 * @table: table of consumers to register
2210 */
2211void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
2212{
2213 mutex_lock(&gpio_lookup_lock);
2214
2215 list_add_tail(&table->list, &gpio_lookup_list);
2216
2217 mutex_unlock(&gpio_lookup_lock);
2218}
2219
2220/**
2221 * gpiod_remove_lookup_table() - unregister GPIO device consumers
2222 * @table: table of consumers to unregister
2223 */
2224void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
2225{
2226 mutex_lock(&gpio_lookup_lock);
2227
2228 list_del(&table->list);
2229
2230 mutex_unlock(&gpio_lookup_lock);
2231}
2232
2233static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
2234 unsigned int idx,
2235 enum gpio_lookup_flags *flags)
2236{
2237 char prop_name[32]; /* 32 is max size of property name */
2238 enum of_gpio_flags of_flags;
2239 struct gpio_desc *desc;
2240 unsigned int i;
2241
2242 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
2243 if (con_id)
2244 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
2245 gpio_suffixes[i]);
2246 else
2247 snprintf(prop_name, sizeof(prop_name), "%s",
2248 gpio_suffixes[i]);
2249
2250 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
2251 &of_flags);
2252 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
2253 break;
2254 }
2255
2256 if (IS_ERR(desc))
2257 return desc;
2258
2259 if (of_flags & OF_GPIO_ACTIVE_LOW)
2260 *flags |= GPIO_ACTIVE_LOW;
2261
2262 if (of_flags & OF_GPIO_SINGLE_ENDED) {
2263 if (of_flags & OF_GPIO_ACTIVE_LOW)
2264 *flags |= GPIO_OPEN_DRAIN;
2265 else
2266 *flags |= GPIO_OPEN_SOURCE;
2267 }
2268
2269 return desc;
2270}
2271
2272static struct gpio_desc *acpi_find_gpio(struct device *dev,
2273 const char *con_id,
2274 unsigned int idx,
2275 enum gpiod_flags flags,
2276 enum gpio_lookup_flags *lookupflags)
2277{
2278 struct acpi_device *adev = ACPI_COMPANION(dev);
2279 struct acpi_gpio_info info;
2280 struct gpio_desc *desc;
2281 char propname[32];
2282 int i;
2283
2284 /* Try first from _DSD */
2285 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
2286 if (con_id && strcmp(con_id, "gpios")) {
2287 snprintf(propname, sizeof(propname), "%s-%s",
2288 con_id, gpio_suffixes[i]);
2289 } else {
2290 snprintf(propname, sizeof(propname), "%s",
2291 gpio_suffixes[i]);
2292 }
2293
2294 desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
2295 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
2296 break;
2297 }
2298
2299 /* Then from plain _CRS GPIOs */
2300 if (IS_ERR(desc)) {
2301 if (!acpi_can_fallback_to_crs(adev, con_id))
2302 return ERR_PTR(-ENOENT);
2303
2304 desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
2305 if (IS_ERR(desc))
2306 return desc;
2307
2308 if ((flags == GPIOD_OUT_LOW || flags == GPIOD_OUT_HIGH) &&
2309 info.gpioint) {
2310 dev_dbg(dev, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n");
2311 return ERR_PTR(-ENOENT);
2312 }
2313 }
2314
2315 if (info.polarity == GPIO_ACTIVE_LOW)
2316 *lookupflags |= GPIO_ACTIVE_LOW;
2317
2318 return desc;
2319}
2320
2321static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
2322{
2323 const char *dev_id = dev ? dev_name(dev) : NULL;
2324 struct gpiod_lookup_table *table;
2325
2326 mutex_lock(&gpio_lookup_lock);
2327
2328 list_for_each_entry(table, &gpio_lookup_list, list) {
2329 if (table->dev_id && dev_id) {
2330 /*
2331 * Valid strings on both ends, must be identical to have
2332 * a match
2333 */
2334 if (!strcmp(table->dev_id, dev_id))
2335 goto found;
2336 } else {
2337 /*
2338 * One of the pointers is NULL, so both must be to have
2339 * a match
2340 */
2341 if (dev_id == table->dev_id)
2342 goto found;
2343 }
2344 }
2345 table = NULL;
2346
2347found:
2348 mutex_unlock(&gpio_lookup_lock);
2349 return table;
2350}
2351
2352static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
2353 unsigned int idx,
2354 enum gpio_lookup_flags *flags)
2355{
2356 struct gpio_desc *desc = ERR_PTR(-ENOENT);
2357 struct gpiod_lookup_table *table;
2358 struct gpiod_lookup *p;
2359
2360 table = gpiod_find_lookup_table(dev);
2361 if (!table)
2362 return desc;
2363
2364 for (p = &table->table[0]; p->chip_label; p++) {
2365 struct gpio_chip *chip;
2366
2367 /* idx must always match exactly */
2368 if (p->idx != idx)
2369 continue;
2370
2371 /* If the lookup entry has a con_id, require exact match */
2372 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
2373 continue;
2374
2375 chip = find_chip_by_name(p->chip_label);
2376
2377 if (!chip) {
2378 dev_err(dev, "cannot find GPIO chip %s\n",
2379 p->chip_label);
2380 return ERR_PTR(-ENODEV);
2381 }
2382
2383 if (chip->ngpio <= p->chip_hwnum) {
2384 dev_err(dev,
2385 "requested GPIO %d is out of range [0..%d] for chip %s\n",
2386 idx, chip->ngpio, chip->label);
2387 return ERR_PTR(-EINVAL);
2388 }
2389
2390 desc = gpiochip_get_desc(chip, p->chip_hwnum);
2391 *flags = p->flags;
2392
2393 return desc;
2394 }
2395
2396 return desc;
2397}
2398
2399static int dt_gpio_count(struct device *dev, const char *con_id)
2400{
2401 int ret;
2402 char propname[32];
2403 unsigned int i;
2404
2405 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
2406 if (con_id)
2407 snprintf(propname, sizeof(propname), "%s-%s",
2408 con_id, gpio_suffixes[i]);
2409 else
2410 snprintf(propname, sizeof(propname), "%s",
2411 gpio_suffixes[i]);
2412
2413 ret = of_gpio_named_count(dev->of_node, propname);
2414 if (ret >= 0)
2415 break;
2416 }
2417 return ret;
2418}
2419
2420static int platform_gpio_count(struct device *dev, const char *con_id)
2421{
2422 struct gpiod_lookup_table *table;
2423 struct gpiod_lookup *p;
2424 unsigned int count = 0;
2425
2426 table = gpiod_find_lookup_table(dev);
2427 if (!table)
2428 return -ENOENT;
2429
2430 for (p = &table->table[0]; p->chip_label; p++) {
2431 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
2432 (!con_id && !p->con_id))
2433 count++;
2434 }
2435 if (!count)
2436 return -ENOENT;
2437
2438 return count;
2439}
2440
2441/**
2442 * gpiod_count - return the number of GPIOs associated with a device / function
2443 * or -ENOENT if no GPIO has been assigned to the requested function
2444 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2445 * @con_id: function within the GPIO consumer
2446 */
2447int gpiod_count(struct device *dev, const char *con_id)
2448{
2449 int count = -ENOENT;
2450
2451 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
2452 count = dt_gpio_count(dev, con_id);
2453 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
2454 count = acpi_gpio_count(dev, con_id);
2455
2456 if (count < 0)
2457 count = platform_gpio_count(dev, con_id);
2458
2459 return count;
2460}
2461EXPORT_SYMBOL_GPL(gpiod_count);
2462
2463/**
2464 * gpiod_get - obtain a GPIO for a given GPIO function
2465 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2466 * @con_id: function within the GPIO consumer
2467 * @flags: optional GPIO initialization flags
2468 *
2469 * Return the GPIO descriptor corresponding to the function con_id of device
2470 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
2471 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
2472 */
2473struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
2474 enum gpiod_flags flags)
2475{
2476 return gpiod_get_index(dev, con_id, 0, flags);
2477}
2478EXPORT_SYMBOL_GPL(gpiod_get);
2479
2480/**
2481 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
2482 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2483 * @con_id: function within the GPIO consumer
2484 * @flags: optional GPIO initialization flags
2485 *
2486 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
2487 * the requested function it will return NULL. This is convenient for drivers
2488 * that need to handle optional GPIOs.
2489 */
2490struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
2491 const char *con_id,
2492 enum gpiod_flags flags)
2493{
2494 return gpiod_get_index_optional(dev, con_id, 0, flags);
2495}
2496EXPORT_SYMBOL_GPL(gpiod_get_optional);
2497
2498/**
2499 * gpiod_parse_flags - helper function to parse GPIO lookup flags
2500 * @desc: gpio to be setup
2501 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2502 * of_get_gpio_hog()
2503 *
2504 * Set the GPIO descriptor flags based on the given GPIO lookup flags.
2505 */
2506static void gpiod_parse_flags(struct gpio_desc *desc, unsigned long lflags)
2507{
2508 if (lflags & GPIO_ACTIVE_LOW)
2509 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
2510 if (lflags & GPIO_OPEN_DRAIN)
2511 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
2512 if (lflags & GPIO_OPEN_SOURCE)
2513 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
2514}
2515
2516/**
2517 * gpiod_configure_flags - helper function to configure a given GPIO
2518 * @desc: gpio whose value will be assigned
2519 * @con_id: function within the GPIO consumer
2520 * @dflags: gpiod_flags - optional GPIO initialization flags
2521 *
2522 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
2523 * requested function and/or index, or another IS_ERR() code if an error
2524 * occurred while trying to acquire the GPIO.
2525 */
2526static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
2527 enum gpiod_flags dflags)
2528{
2529 int status;
2530
2531 /* No particular flag request, return here... */
2532 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
2533 pr_debug("no flags found for %s\n", con_id);
2534 return 0;
2535 }
2536
2537 /* Process flags */
2538 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
2539 status = gpiod_direction_output(desc,
2540 dflags & GPIOD_FLAGS_BIT_DIR_VAL);
2541 else
2542 status = gpiod_direction_input(desc);
2543
2544 return status;
2545}
2546
2547/**
2548 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
2549 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2550 * @con_id: function within the GPIO consumer
2551 * @idx: index of the GPIO to obtain in the consumer
2552 * @flags: optional GPIO initialization flags
2553 *
2554 * This variant of gpiod_get() allows to access GPIOs other than the first
2555 * defined one for functions that define several GPIOs.
2556 *
2557 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
2558 * requested function and/or index, or another IS_ERR() code if an error
2559 * occurred while trying to acquire the GPIO.
2560 */
2561struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
2562 const char *con_id,
2563 unsigned int idx,
2564 enum gpiod_flags flags)
2565{
2566 struct gpio_desc *desc = NULL;
2567 int status;
2568 enum gpio_lookup_flags lookupflags = 0;
2569
2570 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
2571
2572 if (dev) {
2573 /* Using device tree? */
2574 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
2575 dev_dbg(dev, "using device tree for GPIO lookup\n");
2576 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
2577 } else if (ACPI_COMPANION(dev)) {
2578 dev_dbg(dev, "using ACPI for GPIO lookup\n");
2579 desc = acpi_find_gpio(dev, con_id, idx, flags, &lookupflags);
2580 }
2581 }
2582
2583 /*
2584 * Either we are not using DT or ACPI, or their lookup did not return
2585 * a result. In that case, use platform lookup as a fallback.
2586 */
2587 if (!desc || desc == ERR_PTR(-ENOENT)) {
2588 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
2589 desc = gpiod_find(dev, con_id, idx, &lookupflags);
2590 }
2591
2592 if (IS_ERR(desc)) {
2593 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
2594 return desc;
2595 }
2596
2597 gpiod_parse_flags(desc, lookupflags);
2598
2599 status = gpiod_request(desc, con_id);
2600 if (status < 0)
2601 return ERR_PTR(status);
2602
2603 status = gpiod_configure_flags(desc, con_id, flags);
2604 if (status < 0) {
2605 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
2606 gpiod_put(desc);
2607 return ERR_PTR(status);
2608 }
2609
2610 return desc;
2611}
2612EXPORT_SYMBOL_GPL(gpiod_get_index);
2613
2614/**
2615 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
2616 * @fwnode: handle of the firmware node
2617 * @propname: name of the firmware property representing the GPIO
2618 *
2619 * This function can be used for drivers that get their configuration
2620 * from firmware.
2621 *
2622 * Function properly finds the corresponding GPIO using whatever is the
2623 * underlying firmware interface and then makes sure that the GPIO
2624 * descriptor is requested before it is returned to the caller.
2625 *
2626 * In case of error an ERR_PTR() is returned.
2627 */
2628struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
2629 const char *propname)
2630{
2631 struct gpio_desc *desc = ERR_PTR(-ENODEV);
2632 bool active_low = false;
2633 bool single_ended = false;
2634 int ret;
2635
2636 if (!fwnode)
2637 return ERR_PTR(-EINVAL);
2638
2639 if (is_of_node(fwnode)) {
2640 enum of_gpio_flags flags;
2641
2642 desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0,
2643 &flags);
2644 if (!IS_ERR(desc)) {
2645 active_low = flags & OF_GPIO_ACTIVE_LOW;
2646 single_ended = flags & OF_GPIO_SINGLE_ENDED;
2647 }
2648 } else if (is_acpi_node(fwnode)) {
2649 struct acpi_gpio_info info;
2650
2651 desc = acpi_node_get_gpiod(fwnode, propname, 0, &info);
2652 if (!IS_ERR(desc))
2653 active_low = info.polarity == GPIO_ACTIVE_LOW;
2654 }
2655
2656 if (IS_ERR(desc))
2657 return desc;
2658
2659 if (active_low)
2660 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
2661
2662 if (single_ended) {
2663 if (active_low)
2664 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
2665 else
2666 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
2667 }
2668
2669 ret = gpiod_request(desc, NULL);
2670 if (ret)
2671 return ERR_PTR(ret);
2672
2673 return desc;
2674}
2675EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
2676
2677/**
2678 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
2679 * function
2680 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2681 * @con_id: function within the GPIO consumer
2682 * @index: index of the GPIO to obtain in the consumer
2683 * @flags: optional GPIO initialization flags
2684 *
2685 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
2686 * specified index was assigned to the requested function it will return NULL.
2687 * This is convenient for drivers that need to handle optional GPIOs.
2688 */
2689struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
2690 const char *con_id,
2691 unsigned int index,
2692 enum gpiod_flags flags)
2693{
2694 struct gpio_desc *desc;
2695
2696 desc = gpiod_get_index(dev, con_id, index, flags);
2697 if (IS_ERR(desc)) {
2698 if (PTR_ERR(desc) == -ENOENT)
2699 return NULL;
2700 }
2701
2702 return desc;
2703}
2704EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
2705
2706/**
2707 * gpiod_hog - Hog the specified GPIO desc given the provided flags
2708 * @desc: gpio whose value will be assigned
2709 * @name: gpio line name
2710 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2711 * of_get_gpio_hog()
2712 * @dflags: gpiod_flags - optional GPIO initialization flags
2713 */
2714int gpiod_hog(struct gpio_desc *desc, const char *name,
2715 unsigned long lflags, enum gpiod_flags dflags)
2716{
2717 struct gpio_chip *chip;
2718 struct gpio_desc *local_desc;
2719 int hwnum;
2720 int status;
2721
2722 chip = gpiod_to_chip(desc);
2723 hwnum = gpio_chip_hwgpio(desc);
2724
2725 gpiod_parse_flags(desc, lflags);
2726
2727 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
2728 if (IS_ERR(local_desc)) {
2729 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed\n",
2730 name, chip->label, hwnum);
2731 return PTR_ERR(local_desc);
2732 }
2733
2734 status = gpiod_configure_flags(desc, name, dflags);
2735 if (status < 0) {
2736 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed\n",
2737 name, chip->label, hwnum);
2738 gpiochip_free_own_desc(desc);
2739 return status;
2740 }
2741
2742 /* Mark GPIO as hogged so it can be identified and removed later */
2743 set_bit(FLAG_IS_HOGGED, &desc->flags);
2744
2745 pr_info("GPIO line %d (%s) hogged as %s%s\n",
2746 desc_to_gpio(desc), name,
2747 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
2748 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
2749 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
2750
2751 return 0;
2752}
2753
2754/**
2755 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
2756 * @chip: gpio chip to act on
2757 *
2758 * This is only used by of_gpiochip_remove to free hogged gpios
2759 */
2760static void gpiochip_free_hogs(struct gpio_chip *chip)
2761{
2762 int id;
2763
2764 for (id = 0; id < chip->ngpio; id++) {
2765 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
2766 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
2767 }
2768}
2769
2770/**
2771 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
2772 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2773 * @con_id: function within the GPIO consumer
2774 * @flags: optional GPIO initialization flags
2775 *
2776 * This function acquires all the GPIOs defined under a given function.
2777 *
2778 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
2779 * no GPIO has been assigned to the requested function, or another IS_ERR()
2780 * code if an error occurred while trying to acquire the GPIOs.
2781 */
2782struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
2783 const char *con_id,
2784 enum gpiod_flags flags)
2785{
2786 struct gpio_desc *desc;
2787 struct gpio_descs *descs;
2788 int count;
2789
2790 count = gpiod_count(dev, con_id);
2791 if (count < 0)
2792 return ERR_PTR(count);
2793
2794 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
2795 GFP_KERNEL);
2796 if (!descs)
2797 return ERR_PTR(-ENOMEM);
2798
2799 for (descs->ndescs = 0; descs->ndescs < count; ) {
2800 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
2801 if (IS_ERR(desc)) {
2802 gpiod_put_array(descs);
2803 return ERR_CAST(desc);
2804 }
2805 descs->desc[descs->ndescs] = desc;
2806 descs->ndescs++;
2807 }
2808 return descs;
2809}
2810EXPORT_SYMBOL_GPL(gpiod_get_array);
2811
2812/**
2813 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
2814 * function
2815 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2816 * @con_id: function within the GPIO consumer
2817 * @flags: optional GPIO initialization flags
2818 *
2819 * This is equivalent to gpiod_get_array(), except that when no GPIO was
2820 * assigned to the requested function it will return NULL.
2821 */
2822struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
2823 const char *con_id,
2824 enum gpiod_flags flags)
2825{
2826 struct gpio_descs *descs;
2827
2828 descs = gpiod_get_array(dev, con_id, flags);
2829 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
2830 return NULL;
2831
2832 return descs;
2833}
2834EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
2835
2836/**
2837 * gpiod_put - dispose of a GPIO descriptor
2838 * @desc: GPIO descriptor to dispose of
2839 *
2840 * No descriptor can be used after gpiod_put() has been called on it.
2841 */
2842void gpiod_put(struct gpio_desc *desc)
2843{
2844 gpiod_free(desc);
2845}
2846EXPORT_SYMBOL_GPL(gpiod_put);
2847
2848/**
2849 * gpiod_put_array - dispose of multiple GPIO descriptors
2850 * @descs: struct gpio_descs containing an array of descriptors
2851 */
2852void gpiod_put_array(struct gpio_descs *descs)
2853{
2854 unsigned int i;
2855
2856 for (i = 0; i < descs->ndescs; i++)
2857 gpiod_put(descs->desc[i]);
2858
2859 kfree(descs);
2860}
2861EXPORT_SYMBOL_GPL(gpiod_put_array);
2862
2863static int __init gpiolib_dev_init(void)
2864{
2865 int ret;
2866
2867 /* Register GPIO sysfs bus */
2868 ret = bus_register(&gpio_bus_type);
2869 if (ret < 0) {
2870 pr_err("gpiolib: could not register GPIO bus type\n");
2871 return ret;
2872 }
2873
2874 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
2875 if (ret < 0) {
2876 pr_err("gpiolib: failed to allocate char dev region\n");
2877 bus_unregister(&gpio_bus_type);
2878 } else {
2879 gpiolib_initialized = true;
2880 gpiochip_setup_devs();
2881 }
2882 return ret;
2883}
2884core_initcall(gpiolib_dev_init);
2885
2886#ifdef CONFIG_DEBUG_FS
2887
2888static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
2889{
2890 unsigned i;
2891 struct gpio_chip *chip = gdev->chip;
2892 unsigned gpio = gdev->base;
2893 struct gpio_desc *gdesc = &gdev->descs[0];
2894 int is_out;
2895 int is_irq;
2896
2897 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
2898 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
2899 if (gdesc->name) {
2900 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
2901 gpio, gdesc->name);
2902 }
2903 continue;
2904 }
2905
2906 gpiod_get_direction(gdesc);
2907 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
2908 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
2909 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
2910 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
2911 is_out ? "out" : "in ",
2912 chip->get
2913 ? (chip->get(chip, i) ? "hi" : "lo")
2914 : "? ",
2915 is_irq ? "IRQ" : " ");
2916 seq_printf(s, "\n");
2917 }
2918}
2919
2920static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
2921{
2922 unsigned long flags;
2923 struct gpio_device *gdev = NULL;
2924 loff_t index = *pos;
2925
2926 s->private = "";
2927
2928 spin_lock_irqsave(&gpio_lock, flags);
2929 list_for_each_entry(gdev, &gpio_devices, list)
2930 if (index-- == 0) {
2931 spin_unlock_irqrestore(&gpio_lock, flags);
2932 return gdev;
2933 }
2934 spin_unlock_irqrestore(&gpio_lock, flags);
2935
2936 return NULL;
2937}
2938
2939static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
2940{
2941 unsigned long flags;
2942 struct gpio_device *gdev = v;
2943 void *ret = NULL;
2944
2945 spin_lock_irqsave(&gpio_lock, flags);
2946 if (list_is_last(&gdev->list, &gpio_devices))
2947 ret = NULL;
2948 else
2949 ret = list_entry(gdev->list.next, struct gpio_device, list);
2950 spin_unlock_irqrestore(&gpio_lock, flags);
2951
2952 s->private = "\n";
2953 ++*pos;
2954
2955 return ret;
2956}
2957
2958static void gpiolib_seq_stop(struct seq_file *s, void *v)
2959{
2960}
2961
2962static int gpiolib_seq_show(struct seq_file *s, void *v)
2963{
2964 struct gpio_device *gdev = v;
2965 struct gpio_chip *chip = gdev->chip;
2966 struct device *parent;
2967
2968 if (!chip) {
2969 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
2970 dev_name(&gdev->dev));
2971 return 0;
2972 }
2973
2974 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
2975 dev_name(&gdev->dev),
2976 gdev->base, gdev->base + gdev->ngpio - 1);
2977 parent = chip->parent;
2978 if (parent)
2979 seq_printf(s, ", parent: %s/%s",
2980 parent->bus ? parent->bus->name : "no-bus",
2981 dev_name(parent));
2982 if (chip->label)
2983 seq_printf(s, ", %s", chip->label);
2984 if (chip->can_sleep)
2985 seq_printf(s, ", can sleep");
2986 seq_printf(s, ":\n");
2987
2988 if (chip->dbg_show)
2989 chip->dbg_show(s, chip);
2990 else
2991 gpiolib_dbg_show(s, gdev);
2992
2993 return 0;
2994}
2995
2996static const struct seq_operations gpiolib_seq_ops = {
2997 .start = gpiolib_seq_start,
2998 .next = gpiolib_seq_next,
2999 .stop = gpiolib_seq_stop,
3000 .show = gpiolib_seq_show,
3001};
3002
3003static int gpiolib_open(struct inode *inode, struct file *file)
3004{
3005 return seq_open(file, &gpiolib_seq_ops);
3006}
3007
3008static const struct file_operations gpiolib_operations = {
3009 .owner = THIS_MODULE,
3010 .open = gpiolib_open,
3011 .read = seq_read,
3012 .llseek = seq_lseek,
3013 .release = seq_release,
3014};
3015
3016static int __init gpiolib_debugfs_init(void)
3017{
3018 /* /sys/kernel/debug/gpio */
3019 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
3020 NULL, NULL, &gpiolib_operations);
3021 return 0;
3022}
3023subsys_initcall(gpiolib_debugfs_init);
3024
3025#endif /* DEBUG_FS */
1#include <linux/bitmap.h>
2#include <linux/kernel.h>
3#include <linux/module.h>
4#include <linux/interrupt.h>
5#include <linux/irq.h>
6#include <linux/spinlock.h>
7#include <linux/list.h>
8#include <linux/device.h>
9#include <linux/err.h>
10#include <linux/debugfs.h>
11#include <linux/seq_file.h>
12#include <linux/gpio.h>
13#include <linux/of_gpio.h>
14#include <linux/idr.h>
15#include <linux/slab.h>
16#include <linux/acpi.h>
17#include <linux/gpio/driver.h>
18#include <linux/gpio/machine.h>
19#include <linux/pinctrl/consumer.h>
20#include <linux/cdev.h>
21#include <linux/fs.h>
22#include <linux/uaccess.h>
23#include <linux/compat.h>
24#include <linux/anon_inodes.h>
25#include <linux/file.h>
26#include <linux/kfifo.h>
27#include <linux/poll.h>
28#include <linux/timekeeping.h>
29#include <uapi/linux/gpio.h>
30
31#include "gpiolib.h"
32
33#define CREATE_TRACE_POINTS
34#include <trace/events/gpio.h>
35
36/* Implementation infrastructure for GPIO interfaces.
37 *
38 * The GPIO programming interface allows for inlining speed-critical
39 * get/set operations for common cases, so that access to SOC-integrated
40 * GPIOs can sometimes cost only an instruction or two per bit.
41 */
42
43
44/* When debugging, extend minimal trust to callers and platform code.
45 * Also emit diagnostic messages that may help initial bringup, when
46 * board setup or driver bugs are most common.
47 *
48 * Otherwise, minimize overhead in what may be bitbanging codepaths.
49 */
50#ifdef DEBUG
51#define extra_checks 1
52#else
53#define extra_checks 0
54#endif
55
56/* Device and char device-related information */
57static DEFINE_IDA(gpio_ida);
58static dev_t gpio_devt;
59#define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
60static struct bus_type gpio_bus_type = {
61 .name = "gpio",
62};
63
64/* gpio_lock prevents conflicts during gpio_desc[] table updates.
65 * While any GPIO is requested, its gpio_chip is not removable;
66 * each GPIO's "requested" flag serves as a lock and refcount.
67 */
68DEFINE_SPINLOCK(gpio_lock);
69
70static DEFINE_MUTEX(gpio_lookup_lock);
71static LIST_HEAD(gpio_lookup_list);
72LIST_HEAD(gpio_devices);
73
74static void gpiochip_free_hogs(struct gpio_chip *chip);
75static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
76 struct lock_class_key *lock_key,
77 struct lock_class_key *request_key);
78static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
79static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
80static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
81
82static bool gpiolib_initialized;
83
84static inline void desc_set_label(struct gpio_desc *d, const char *label)
85{
86 d->label = label;
87}
88
89/**
90 * gpio_to_desc - Convert a GPIO number to its descriptor
91 * @gpio: global GPIO number
92 *
93 * Returns:
94 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
95 * with the given number exists in the system.
96 */
97struct gpio_desc *gpio_to_desc(unsigned gpio)
98{
99 struct gpio_device *gdev;
100 unsigned long flags;
101
102 spin_lock_irqsave(&gpio_lock, flags);
103
104 list_for_each_entry(gdev, &gpio_devices, list) {
105 if (gdev->base <= gpio &&
106 gdev->base + gdev->ngpio > gpio) {
107 spin_unlock_irqrestore(&gpio_lock, flags);
108 return &gdev->descs[gpio - gdev->base];
109 }
110 }
111
112 spin_unlock_irqrestore(&gpio_lock, flags);
113
114 if (!gpio_is_valid(gpio))
115 WARN(1, "invalid GPIO %d\n", gpio);
116
117 return NULL;
118}
119EXPORT_SYMBOL_GPL(gpio_to_desc);
120
121/**
122 * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
123 * hardware number for this chip
124 * @chip: GPIO chip
125 * @hwnum: hardware number of the GPIO for this chip
126 *
127 * Returns:
128 * A pointer to the GPIO descriptor or %ERR_PTR(-EINVAL) if no GPIO exists
129 * in the given chip for the specified hardware number.
130 */
131struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
132 u16 hwnum)
133{
134 struct gpio_device *gdev = chip->gpiodev;
135
136 if (hwnum >= gdev->ngpio)
137 return ERR_PTR(-EINVAL);
138
139 return &gdev->descs[hwnum];
140}
141
142/**
143 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
144 * @desc: GPIO descriptor
145 *
146 * This should disappear in the future but is needed since we still
147 * use GPIO numbers for error messages and sysfs nodes.
148 *
149 * Returns:
150 * The global GPIO number for the GPIO specified by its descriptor.
151 */
152int desc_to_gpio(const struct gpio_desc *desc)
153{
154 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
155}
156EXPORT_SYMBOL_GPL(desc_to_gpio);
157
158
159/**
160 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
161 * @desc: descriptor to return the chip of
162 */
163struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
164{
165 if (!desc || !desc->gdev)
166 return NULL;
167 return desc->gdev->chip;
168}
169EXPORT_SYMBOL_GPL(gpiod_to_chip);
170
171/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
172static int gpiochip_find_base(int ngpio)
173{
174 struct gpio_device *gdev;
175 int base = ARCH_NR_GPIOS - ngpio;
176
177 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
178 /* found a free space? */
179 if (gdev->base + gdev->ngpio <= base)
180 break;
181 else
182 /* nope, check the space right before the chip */
183 base = gdev->base - ngpio;
184 }
185
186 if (gpio_is_valid(base)) {
187 pr_debug("%s: found new base at %d\n", __func__, base);
188 return base;
189 } else {
190 pr_err("%s: cannot find free range\n", __func__);
191 return -ENOSPC;
192 }
193}
194
195/**
196 * gpiod_get_direction - return the current direction of a GPIO
197 * @desc: GPIO to get the direction of
198 *
199 * Returns 0 for output, 1 for input, or an error code in case of error.
200 *
201 * This function may sleep if gpiod_cansleep() is true.
202 */
203int gpiod_get_direction(struct gpio_desc *desc)
204{
205 struct gpio_chip *chip;
206 unsigned offset;
207 int status = -EINVAL;
208
209 chip = gpiod_to_chip(desc);
210 offset = gpio_chip_hwgpio(desc);
211
212 if (!chip->get_direction)
213 return status;
214
215 status = chip->get_direction(chip, offset);
216 if (status > 0) {
217 /* GPIOF_DIR_IN, or other positive */
218 status = 1;
219 clear_bit(FLAG_IS_OUT, &desc->flags);
220 }
221 if (status == 0) {
222 /* GPIOF_DIR_OUT */
223 set_bit(FLAG_IS_OUT, &desc->flags);
224 }
225 return status;
226}
227EXPORT_SYMBOL_GPL(gpiod_get_direction);
228
229/*
230 * Add a new chip to the global chips list, keeping the list of chips sorted
231 * by range(means [base, base + ngpio - 1]) order.
232 *
233 * Return -EBUSY if the new chip overlaps with some other chip's integer
234 * space.
235 */
236static int gpiodev_add_to_list(struct gpio_device *gdev)
237{
238 struct gpio_device *prev, *next;
239
240 if (list_empty(&gpio_devices)) {
241 /* initial entry in list */
242 list_add_tail(&gdev->list, &gpio_devices);
243 return 0;
244 }
245
246 next = list_entry(gpio_devices.next, struct gpio_device, list);
247 if (gdev->base + gdev->ngpio <= next->base) {
248 /* add before first entry */
249 list_add(&gdev->list, &gpio_devices);
250 return 0;
251 }
252
253 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
254 if (prev->base + prev->ngpio <= gdev->base) {
255 /* add behind last entry */
256 list_add_tail(&gdev->list, &gpio_devices);
257 return 0;
258 }
259
260 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
261 /* at the end of the list */
262 if (&next->list == &gpio_devices)
263 break;
264
265 /* add between prev and next */
266 if (prev->base + prev->ngpio <= gdev->base
267 && gdev->base + gdev->ngpio <= next->base) {
268 list_add(&gdev->list, &prev->list);
269 return 0;
270 }
271 }
272
273 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
274 return -EBUSY;
275}
276
277/*
278 * Convert a GPIO name to its descriptor
279 */
280static struct gpio_desc *gpio_name_to_desc(const char * const name)
281{
282 struct gpio_device *gdev;
283 unsigned long flags;
284
285 spin_lock_irqsave(&gpio_lock, flags);
286
287 list_for_each_entry(gdev, &gpio_devices, list) {
288 int i;
289
290 for (i = 0; i != gdev->ngpio; ++i) {
291 struct gpio_desc *desc = &gdev->descs[i];
292
293 if (!desc->name || !name)
294 continue;
295
296 if (!strcmp(desc->name, name)) {
297 spin_unlock_irqrestore(&gpio_lock, flags);
298 return desc;
299 }
300 }
301 }
302
303 spin_unlock_irqrestore(&gpio_lock, flags);
304
305 return NULL;
306}
307
308/*
309 * Takes the names from gc->names and checks if they are all unique. If they
310 * are, they are assigned to their gpio descriptors.
311 *
312 * Warning if one of the names is already used for a different GPIO.
313 */
314static int gpiochip_set_desc_names(struct gpio_chip *gc)
315{
316 struct gpio_device *gdev = gc->gpiodev;
317 int i;
318
319 if (!gc->names)
320 return 0;
321
322 /* First check all names if they are unique */
323 for (i = 0; i != gc->ngpio; ++i) {
324 struct gpio_desc *gpio;
325
326 gpio = gpio_name_to_desc(gc->names[i]);
327 if (gpio)
328 dev_warn(&gdev->dev,
329 "Detected name collision for GPIO name '%s'\n",
330 gc->names[i]);
331 }
332
333 /* Then add all names to the GPIO descriptors */
334 for (i = 0; i != gc->ngpio; ++i)
335 gdev->descs[i].name = gc->names[i];
336
337 return 0;
338}
339
340static unsigned long *gpiochip_allocate_mask(struct gpio_chip *chip)
341{
342 unsigned long *p;
343
344 p = kmalloc_array(BITS_TO_LONGS(chip->ngpio), sizeof(*p), GFP_KERNEL);
345 if (!p)
346 return NULL;
347
348 /* Assume by default all GPIOs are valid */
349 bitmap_fill(p, chip->ngpio);
350
351 return p;
352}
353
354static int gpiochip_init_valid_mask(struct gpio_chip *gpiochip)
355{
356#ifdef CONFIG_OF_GPIO
357 int size;
358 struct device_node *np = gpiochip->of_node;
359
360 size = of_property_count_u32_elems(np, "gpio-reserved-ranges");
361 if (size > 0 && size % 2 == 0)
362 gpiochip->need_valid_mask = true;
363#endif
364
365 if (!gpiochip->need_valid_mask)
366 return 0;
367
368 gpiochip->valid_mask = gpiochip_allocate_mask(gpiochip);
369 if (!gpiochip->valid_mask)
370 return -ENOMEM;
371
372 return 0;
373}
374
375static void gpiochip_free_valid_mask(struct gpio_chip *gpiochip)
376{
377 kfree(gpiochip->valid_mask);
378 gpiochip->valid_mask = NULL;
379}
380
381bool gpiochip_line_is_valid(const struct gpio_chip *gpiochip,
382 unsigned int offset)
383{
384 /* No mask means all valid */
385 if (likely(!gpiochip->valid_mask))
386 return true;
387 return test_bit(offset, gpiochip->valid_mask);
388}
389EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
390
391/*
392 * GPIO line handle management
393 */
394
395/**
396 * struct linehandle_state - contains the state of a userspace handle
397 * @gdev: the GPIO device the handle pertains to
398 * @label: consumer label used to tag descriptors
399 * @descs: the GPIO descriptors held by this handle
400 * @numdescs: the number of descriptors held in the descs array
401 */
402struct linehandle_state {
403 struct gpio_device *gdev;
404 const char *label;
405 struct gpio_desc *descs[GPIOHANDLES_MAX];
406 u32 numdescs;
407};
408
409#define GPIOHANDLE_REQUEST_VALID_FLAGS \
410 (GPIOHANDLE_REQUEST_INPUT | \
411 GPIOHANDLE_REQUEST_OUTPUT | \
412 GPIOHANDLE_REQUEST_ACTIVE_LOW | \
413 GPIOHANDLE_REQUEST_OPEN_DRAIN | \
414 GPIOHANDLE_REQUEST_OPEN_SOURCE)
415
416static long linehandle_ioctl(struct file *filep, unsigned int cmd,
417 unsigned long arg)
418{
419 struct linehandle_state *lh = filep->private_data;
420 void __user *ip = (void __user *)arg;
421 struct gpiohandle_data ghd;
422 int vals[GPIOHANDLES_MAX];
423 int i;
424
425 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
426 /* TODO: check if descriptors are really input */
427 int ret = gpiod_get_array_value_complex(false,
428 true,
429 lh->numdescs,
430 lh->descs,
431 vals);
432 if (ret)
433 return ret;
434
435 memset(&ghd, 0, sizeof(ghd));
436 for (i = 0; i < lh->numdescs; i++)
437 ghd.values[i] = vals[i];
438
439 if (copy_to_user(ip, &ghd, sizeof(ghd)))
440 return -EFAULT;
441
442 return 0;
443 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
444 /* TODO: check if descriptors are really output */
445 if (copy_from_user(&ghd, ip, sizeof(ghd)))
446 return -EFAULT;
447
448 /* Clamp all values to [0,1] */
449 for (i = 0; i < lh->numdescs; i++)
450 vals[i] = !!ghd.values[i];
451
452 /* Reuse the array setting function */
453 gpiod_set_array_value_complex(false,
454 true,
455 lh->numdescs,
456 lh->descs,
457 vals);
458 return 0;
459 }
460 return -EINVAL;
461}
462
463#ifdef CONFIG_COMPAT
464static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
465 unsigned long arg)
466{
467 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
468}
469#endif
470
471static int linehandle_release(struct inode *inode, struct file *filep)
472{
473 struct linehandle_state *lh = filep->private_data;
474 struct gpio_device *gdev = lh->gdev;
475 int i;
476
477 for (i = 0; i < lh->numdescs; i++)
478 gpiod_free(lh->descs[i]);
479 kfree(lh->label);
480 kfree(lh);
481 put_device(&gdev->dev);
482 return 0;
483}
484
485static const struct file_operations linehandle_fileops = {
486 .release = linehandle_release,
487 .owner = THIS_MODULE,
488 .llseek = noop_llseek,
489 .unlocked_ioctl = linehandle_ioctl,
490#ifdef CONFIG_COMPAT
491 .compat_ioctl = linehandle_ioctl_compat,
492#endif
493};
494
495static int linehandle_create(struct gpio_device *gdev, void __user *ip)
496{
497 struct gpiohandle_request handlereq;
498 struct linehandle_state *lh;
499 struct file *file;
500 int fd, i, count = 0, ret;
501 u32 lflags;
502
503 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
504 return -EFAULT;
505 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
506 return -EINVAL;
507
508 lflags = handlereq.flags;
509
510 /* Return an error if an unknown flag is set */
511 if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
512 return -EINVAL;
513
514 /*
515 * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
516 * the hardware actually supports enabling both at the same time the
517 * electrical result would be disastrous.
518 */
519 if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
520 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
521 return -EINVAL;
522
523 /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
524 if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) &&
525 ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
526 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
527 return -EINVAL;
528
529 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
530 if (!lh)
531 return -ENOMEM;
532 lh->gdev = gdev;
533 get_device(&gdev->dev);
534
535 /* Make sure this is terminated */
536 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
537 if (strlen(handlereq.consumer_label)) {
538 lh->label = kstrdup(handlereq.consumer_label,
539 GFP_KERNEL);
540 if (!lh->label) {
541 ret = -ENOMEM;
542 goto out_free_lh;
543 }
544 }
545
546 /* Request each GPIO */
547 for (i = 0; i < handlereq.lines; i++) {
548 u32 offset = handlereq.lineoffsets[i];
549 struct gpio_desc *desc;
550
551 if (offset >= gdev->ngpio) {
552 ret = -EINVAL;
553 goto out_free_descs;
554 }
555
556 desc = &gdev->descs[offset];
557 ret = gpiod_request(desc, lh->label);
558 if (ret)
559 goto out_free_descs;
560 lh->descs[i] = desc;
561 count = i;
562
563 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
564 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
565 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
566 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
567 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
568 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
569
570 ret = gpiod_set_transitory(desc, false);
571 if (ret < 0)
572 goto out_free_descs;
573
574 /*
575 * Lines have to be requested explicitly for input
576 * or output, else the line will be treated "as is".
577 */
578 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
579 int val = !!handlereq.default_values[i];
580
581 ret = gpiod_direction_output(desc, val);
582 if (ret)
583 goto out_free_descs;
584 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
585 ret = gpiod_direction_input(desc);
586 if (ret)
587 goto out_free_descs;
588 }
589 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
590 offset);
591 }
592 /* Let i point at the last handle */
593 i--;
594 lh->numdescs = handlereq.lines;
595
596 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
597 if (fd < 0) {
598 ret = fd;
599 goto out_free_descs;
600 }
601
602 file = anon_inode_getfile("gpio-linehandle",
603 &linehandle_fileops,
604 lh,
605 O_RDONLY | O_CLOEXEC);
606 if (IS_ERR(file)) {
607 ret = PTR_ERR(file);
608 goto out_put_unused_fd;
609 }
610
611 handlereq.fd = fd;
612 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
613 /*
614 * fput() will trigger the release() callback, so do not go onto
615 * the regular error cleanup path here.
616 */
617 fput(file);
618 put_unused_fd(fd);
619 return -EFAULT;
620 }
621
622 fd_install(fd, file);
623
624 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
625 lh->numdescs);
626
627 return 0;
628
629out_put_unused_fd:
630 put_unused_fd(fd);
631out_free_descs:
632 for (i = 0; i < count; i++)
633 gpiod_free(lh->descs[i]);
634 kfree(lh->label);
635out_free_lh:
636 kfree(lh);
637 put_device(&gdev->dev);
638 return ret;
639}
640
641/*
642 * GPIO line event management
643 */
644
645/**
646 * struct lineevent_state - contains the state of a userspace event
647 * @gdev: the GPIO device the event pertains to
648 * @label: consumer label used to tag descriptors
649 * @desc: the GPIO descriptor held by this event
650 * @eflags: the event flags this line was requested with
651 * @irq: the interrupt that trigger in response to events on this GPIO
652 * @wait: wait queue that handles blocking reads of events
653 * @events: KFIFO for the GPIO events
654 * @read_lock: mutex lock to protect reads from colliding with adding
655 * new events to the FIFO
656 * @timestamp: cache for the timestamp storing it between hardirq
657 * and IRQ thread, used to bring the timestamp close to the actual
658 * event
659 */
660struct lineevent_state {
661 struct gpio_device *gdev;
662 const char *label;
663 struct gpio_desc *desc;
664 u32 eflags;
665 int irq;
666 wait_queue_head_t wait;
667 DECLARE_KFIFO(events, struct gpioevent_data, 16);
668 struct mutex read_lock;
669 u64 timestamp;
670};
671
672#define GPIOEVENT_REQUEST_VALID_FLAGS \
673 (GPIOEVENT_REQUEST_RISING_EDGE | \
674 GPIOEVENT_REQUEST_FALLING_EDGE)
675
676static __poll_t lineevent_poll(struct file *filep,
677 struct poll_table_struct *wait)
678{
679 struct lineevent_state *le = filep->private_data;
680 __poll_t events = 0;
681
682 poll_wait(filep, &le->wait, wait);
683
684 if (!kfifo_is_empty(&le->events))
685 events = EPOLLIN | EPOLLRDNORM;
686
687 return events;
688}
689
690
691static ssize_t lineevent_read(struct file *filep,
692 char __user *buf,
693 size_t count,
694 loff_t *f_ps)
695{
696 struct lineevent_state *le = filep->private_data;
697 unsigned int copied;
698 int ret;
699
700 if (count < sizeof(struct gpioevent_data))
701 return -EINVAL;
702
703 do {
704 if (kfifo_is_empty(&le->events)) {
705 if (filep->f_flags & O_NONBLOCK)
706 return -EAGAIN;
707
708 ret = wait_event_interruptible(le->wait,
709 !kfifo_is_empty(&le->events));
710 if (ret)
711 return ret;
712 }
713
714 if (mutex_lock_interruptible(&le->read_lock))
715 return -ERESTARTSYS;
716 ret = kfifo_to_user(&le->events, buf, count, &copied);
717 mutex_unlock(&le->read_lock);
718
719 if (ret)
720 return ret;
721
722 /*
723 * If we couldn't read anything from the fifo (a different
724 * thread might have been faster) we either return -EAGAIN if
725 * the file descriptor is non-blocking, otherwise we go back to
726 * sleep and wait for more data to arrive.
727 */
728 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
729 return -EAGAIN;
730
731 } while (copied == 0);
732
733 return copied;
734}
735
736static int lineevent_release(struct inode *inode, struct file *filep)
737{
738 struct lineevent_state *le = filep->private_data;
739 struct gpio_device *gdev = le->gdev;
740
741 free_irq(le->irq, le);
742 gpiod_free(le->desc);
743 kfree(le->label);
744 kfree(le);
745 put_device(&gdev->dev);
746 return 0;
747}
748
749static long lineevent_ioctl(struct file *filep, unsigned int cmd,
750 unsigned long arg)
751{
752 struct lineevent_state *le = filep->private_data;
753 void __user *ip = (void __user *)arg;
754 struct gpiohandle_data ghd;
755
756 /*
757 * We can get the value for an event line but not set it,
758 * because it is input by definition.
759 */
760 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
761 int val;
762
763 memset(&ghd, 0, sizeof(ghd));
764
765 val = gpiod_get_value_cansleep(le->desc);
766 if (val < 0)
767 return val;
768 ghd.values[0] = val;
769
770 if (copy_to_user(ip, &ghd, sizeof(ghd)))
771 return -EFAULT;
772
773 return 0;
774 }
775 return -EINVAL;
776}
777
778#ifdef CONFIG_COMPAT
779static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
780 unsigned long arg)
781{
782 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
783}
784#endif
785
786static const struct file_operations lineevent_fileops = {
787 .release = lineevent_release,
788 .read = lineevent_read,
789 .poll = lineevent_poll,
790 .owner = THIS_MODULE,
791 .llseek = noop_llseek,
792 .unlocked_ioctl = lineevent_ioctl,
793#ifdef CONFIG_COMPAT
794 .compat_ioctl = lineevent_ioctl_compat,
795#endif
796};
797
798static irqreturn_t lineevent_irq_thread(int irq, void *p)
799{
800 struct lineevent_state *le = p;
801 struct gpioevent_data ge;
802 int ret, level;
803
804 /* Do not leak kernel stack to userspace */
805 memset(&ge, 0, sizeof(ge));
806
807 ge.timestamp = le->timestamp;
808 level = gpiod_get_value_cansleep(le->desc);
809
810 if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
811 && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
812 if (level)
813 /* Emit low-to-high event */
814 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
815 else
816 /* Emit high-to-low event */
817 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
818 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE && level) {
819 /* Emit low-to-high event */
820 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
821 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE && !level) {
822 /* Emit high-to-low event */
823 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
824 } else {
825 return IRQ_NONE;
826 }
827
828 ret = kfifo_put(&le->events, ge);
829 if (ret != 0)
830 wake_up_poll(&le->wait, EPOLLIN);
831
832 return IRQ_HANDLED;
833}
834
835static irqreturn_t lineevent_irq_handler(int irq, void *p)
836{
837 struct lineevent_state *le = p;
838
839 /*
840 * Just store the timestamp in hardirq context so we get it as
841 * close in time as possible to the actual event.
842 */
843 le->timestamp = ktime_get_real_ns();
844
845 return IRQ_WAKE_THREAD;
846}
847
848static int lineevent_create(struct gpio_device *gdev, void __user *ip)
849{
850 struct gpioevent_request eventreq;
851 struct lineevent_state *le;
852 struct gpio_desc *desc;
853 struct file *file;
854 u32 offset;
855 u32 lflags;
856 u32 eflags;
857 int fd;
858 int ret;
859 int irqflags = 0;
860
861 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
862 return -EFAULT;
863
864 le = kzalloc(sizeof(*le), GFP_KERNEL);
865 if (!le)
866 return -ENOMEM;
867 le->gdev = gdev;
868 get_device(&gdev->dev);
869
870 /* Make sure this is terminated */
871 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
872 if (strlen(eventreq.consumer_label)) {
873 le->label = kstrdup(eventreq.consumer_label,
874 GFP_KERNEL);
875 if (!le->label) {
876 ret = -ENOMEM;
877 goto out_free_le;
878 }
879 }
880
881 offset = eventreq.lineoffset;
882 lflags = eventreq.handleflags;
883 eflags = eventreq.eventflags;
884
885 if (offset >= gdev->ngpio) {
886 ret = -EINVAL;
887 goto out_free_label;
888 }
889
890 /* Return an error if a unknown flag is set */
891 if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
892 (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
893 ret = -EINVAL;
894 goto out_free_label;
895 }
896
897 /* This is just wrong: we don't look for events on output lines */
898 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
899 ret = -EINVAL;
900 goto out_free_label;
901 }
902
903 desc = &gdev->descs[offset];
904 ret = gpiod_request(desc, le->label);
905 if (ret)
906 goto out_free_label;
907 le->desc = desc;
908 le->eflags = eflags;
909
910 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
911 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
912 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
913 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
914 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
915 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
916
917 ret = gpiod_direction_input(desc);
918 if (ret)
919 goto out_free_desc;
920
921 le->irq = gpiod_to_irq(desc);
922 if (le->irq <= 0) {
923 ret = -ENODEV;
924 goto out_free_desc;
925 }
926
927 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
928 irqflags |= IRQF_TRIGGER_RISING;
929 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
930 irqflags |= IRQF_TRIGGER_FALLING;
931 irqflags |= IRQF_ONESHOT;
932 irqflags |= IRQF_SHARED;
933
934 INIT_KFIFO(le->events);
935 init_waitqueue_head(&le->wait);
936 mutex_init(&le->read_lock);
937
938 /* Request a thread to read the events */
939 ret = request_threaded_irq(le->irq,
940 lineevent_irq_handler,
941 lineevent_irq_thread,
942 irqflags,
943 le->label,
944 le);
945 if (ret)
946 goto out_free_desc;
947
948 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
949 if (fd < 0) {
950 ret = fd;
951 goto out_free_irq;
952 }
953
954 file = anon_inode_getfile("gpio-event",
955 &lineevent_fileops,
956 le,
957 O_RDONLY | O_CLOEXEC);
958 if (IS_ERR(file)) {
959 ret = PTR_ERR(file);
960 goto out_put_unused_fd;
961 }
962
963 eventreq.fd = fd;
964 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
965 /*
966 * fput() will trigger the release() callback, so do not go onto
967 * the regular error cleanup path here.
968 */
969 fput(file);
970 put_unused_fd(fd);
971 return -EFAULT;
972 }
973
974 fd_install(fd, file);
975
976 return 0;
977
978out_put_unused_fd:
979 put_unused_fd(fd);
980out_free_irq:
981 free_irq(le->irq, le);
982out_free_desc:
983 gpiod_free(le->desc);
984out_free_label:
985 kfree(le->label);
986out_free_le:
987 kfree(le);
988 put_device(&gdev->dev);
989 return ret;
990}
991
992/*
993 * gpio_ioctl() - ioctl handler for the GPIO chardev
994 */
995static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
996{
997 struct gpio_device *gdev = filp->private_data;
998 struct gpio_chip *chip = gdev->chip;
999 void __user *ip = (void __user *)arg;
1000
1001 /* We fail any subsequent ioctl():s when the chip is gone */
1002 if (!chip)
1003 return -ENODEV;
1004
1005 /* Fill in the struct and pass to userspace */
1006 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
1007 struct gpiochip_info chipinfo;
1008
1009 memset(&chipinfo, 0, sizeof(chipinfo));
1010
1011 strncpy(chipinfo.name, dev_name(&gdev->dev),
1012 sizeof(chipinfo.name));
1013 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
1014 strncpy(chipinfo.label, gdev->label,
1015 sizeof(chipinfo.label));
1016 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
1017 chipinfo.lines = gdev->ngpio;
1018 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
1019 return -EFAULT;
1020 return 0;
1021 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
1022 struct gpioline_info lineinfo;
1023 struct gpio_desc *desc;
1024
1025 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
1026 return -EFAULT;
1027 if (lineinfo.line_offset >= gdev->ngpio)
1028 return -EINVAL;
1029
1030 desc = &gdev->descs[lineinfo.line_offset];
1031 if (desc->name) {
1032 strncpy(lineinfo.name, desc->name,
1033 sizeof(lineinfo.name));
1034 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
1035 } else {
1036 lineinfo.name[0] = '\0';
1037 }
1038 if (desc->label) {
1039 strncpy(lineinfo.consumer, desc->label,
1040 sizeof(lineinfo.consumer));
1041 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
1042 } else {
1043 lineinfo.consumer[0] = '\0';
1044 }
1045
1046 /*
1047 * Userspace only need to know that the kernel is using
1048 * this GPIO so it can't use it.
1049 */
1050 lineinfo.flags = 0;
1051 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
1052 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
1053 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
1054 test_bit(FLAG_EXPORT, &desc->flags) ||
1055 test_bit(FLAG_SYSFS, &desc->flags))
1056 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
1057 if (test_bit(FLAG_IS_OUT, &desc->flags))
1058 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
1059 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1060 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
1061 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1062 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
1063 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1064 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
1065
1066 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
1067 return -EFAULT;
1068 return 0;
1069 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
1070 return linehandle_create(gdev, ip);
1071 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
1072 return lineevent_create(gdev, ip);
1073 }
1074 return -EINVAL;
1075}
1076
1077#ifdef CONFIG_COMPAT
1078static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
1079 unsigned long arg)
1080{
1081 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
1082}
1083#endif
1084
1085/**
1086 * gpio_chrdev_open() - open the chardev for ioctl operations
1087 * @inode: inode for this chardev
1088 * @filp: file struct for storing private data
1089 * Returns 0 on success
1090 */
1091static int gpio_chrdev_open(struct inode *inode, struct file *filp)
1092{
1093 struct gpio_device *gdev = container_of(inode->i_cdev,
1094 struct gpio_device, chrdev);
1095
1096 /* Fail on open if the backing gpiochip is gone */
1097 if (!gdev->chip)
1098 return -ENODEV;
1099 get_device(&gdev->dev);
1100 filp->private_data = gdev;
1101
1102 return nonseekable_open(inode, filp);
1103}
1104
1105/**
1106 * gpio_chrdev_release() - close chardev after ioctl operations
1107 * @inode: inode for this chardev
1108 * @filp: file struct for storing private data
1109 * Returns 0 on success
1110 */
1111static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1112{
1113 struct gpio_device *gdev = container_of(inode->i_cdev,
1114 struct gpio_device, chrdev);
1115
1116 put_device(&gdev->dev);
1117 return 0;
1118}
1119
1120
1121static const struct file_operations gpio_fileops = {
1122 .release = gpio_chrdev_release,
1123 .open = gpio_chrdev_open,
1124 .owner = THIS_MODULE,
1125 .llseek = no_llseek,
1126 .unlocked_ioctl = gpio_ioctl,
1127#ifdef CONFIG_COMPAT
1128 .compat_ioctl = gpio_ioctl_compat,
1129#endif
1130};
1131
1132static void gpiodevice_release(struct device *dev)
1133{
1134 struct gpio_device *gdev = dev_get_drvdata(dev);
1135
1136 list_del(&gdev->list);
1137 ida_simple_remove(&gpio_ida, gdev->id);
1138 kfree_const(gdev->label);
1139 kfree(gdev->descs);
1140 kfree(gdev);
1141}
1142
1143static int gpiochip_setup_dev(struct gpio_device *gdev)
1144{
1145 int status;
1146
1147 cdev_init(&gdev->chrdev, &gpio_fileops);
1148 gdev->chrdev.owner = THIS_MODULE;
1149 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1150
1151 status = cdev_device_add(&gdev->chrdev, &gdev->dev);
1152 if (status)
1153 return status;
1154
1155 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1156 MAJOR(gpio_devt), gdev->id);
1157
1158 status = gpiochip_sysfs_register(gdev);
1159 if (status)
1160 goto err_remove_device;
1161
1162 /* From this point, the .release() function cleans up gpio_device */
1163 gdev->dev.release = gpiodevice_release;
1164 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1165 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1166 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1167
1168 return 0;
1169
1170err_remove_device:
1171 cdev_device_del(&gdev->chrdev, &gdev->dev);
1172 return status;
1173}
1174
1175static void gpiochip_setup_devs(void)
1176{
1177 struct gpio_device *gdev;
1178 int err;
1179
1180 list_for_each_entry(gdev, &gpio_devices, list) {
1181 err = gpiochip_setup_dev(gdev);
1182 if (err)
1183 pr_err("%s: Failed to initialize gpio device (%d)\n",
1184 dev_name(&gdev->dev), err);
1185 }
1186}
1187
1188int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
1189 struct lock_class_key *lock_key,
1190 struct lock_class_key *request_key)
1191{
1192 unsigned long flags;
1193 int status = 0;
1194 unsigned i;
1195 int base = chip->base;
1196 struct gpio_device *gdev;
1197
1198 /*
1199 * First: allocate and populate the internal stat container, and
1200 * set up the struct device.
1201 */
1202 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1203 if (!gdev)
1204 return -ENOMEM;
1205 gdev->dev.bus = &gpio_bus_type;
1206 gdev->chip = chip;
1207 chip->gpiodev = gdev;
1208 if (chip->parent) {
1209 gdev->dev.parent = chip->parent;
1210 gdev->dev.of_node = chip->parent->of_node;
1211 }
1212
1213#ifdef CONFIG_OF_GPIO
1214 /* If the gpiochip has an assigned OF node this takes precedence */
1215 if (chip->of_node)
1216 gdev->dev.of_node = chip->of_node;
1217#endif
1218
1219 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1220 if (gdev->id < 0) {
1221 status = gdev->id;
1222 goto err_free_gdev;
1223 }
1224 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1225 device_initialize(&gdev->dev);
1226 dev_set_drvdata(&gdev->dev, gdev);
1227 if (chip->parent && chip->parent->driver)
1228 gdev->owner = chip->parent->driver->owner;
1229 else if (chip->owner)
1230 /* TODO: remove chip->owner */
1231 gdev->owner = chip->owner;
1232 else
1233 gdev->owner = THIS_MODULE;
1234
1235 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1236 if (!gdev->descs) {
1237 status = -ENOMEM;
1238 goto err_free_gdev;
1239 }
1240
1241 if (chip->ngpio == 0) {
1242 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1243 status = -EINVAL;
1244 goto err_free_descs;
1245 }
1246
1247 gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
1248 if (!gdev->label) {
1249 status = -ENOMEM;
1250 goto err_free_descs;
1251 }
1252
1253 gdev->ngpio = chip->ngpio;
1254 gdev->data = data;
1255
1256 spin_lock_irqsave(&gpio_lock, flags);
1257
1258 /*
1259 * TODO: this allocates a Linux GPIO number base in the global
1260 * GPIO numberspace for this chip. In the long run we want to
1261 * get *rid* of this numberspace and use only descriptors, but
1262 * it may be a pipe dream. It will not happen before we get rid
1263 * of the sysfs interface anyways.
1264 */
1265 if (base < 0) {
1266 base = gpiochip_find_base(chip->ngpio);
1267 if (base < 0) {
1268 status = base;
1269 spin_unlock_irqrestore(&gpio_lock, flags);
1270 goto err_free_label;
1271 }
1272 /*
1273 * TODO: it should not be necessary to reflect the assigned
1274 * base outside of the GPIO subsystem. Go over drivers and
1275 * see if anyone makes use of this, else drop this and assign
1276 * a poison instead.
1277 */
1278 chip->base = base;
1279 }
1280 gdev->base = base;
1281
1282 status = gpiodev_add_to_list(gdev);
1283 if (status) {
1284 spin_unlock_irqrestore(&gpio_lock, flags);
1285 goto err_free_label;
1286 }
1287
1288 spin_unlock_irqrestore(&gpio_lock, flags);
1289
1290 for (i = 0; i < chip->ngpio; i++) {
1291 struct gpio_desc *desc = &gdev->descs[i];
1292
1293 desc->gdev = gdev;
1294
1295 /* REVISIT: most hardware initializes GPIOs as inputs (often
1296 * with pullups enabled) so power usage is minimized. Linux
1297 * code should set the gpio direction first thing; but until
1298 * it does, and in case chip->get_direction is not set, we may
1299 * expose the wrong direction in sysfs.
1300 */
1301 desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
1302 }
1303
1304#ifdef CONFIG_PINCTRL
1305 INIT_LIST_HEAD(&gdev->pin_ranges);
1306#endif
1307
1308 status = gpiochip_set_desc_names(chip);
1309 if (status)
1310 goto err_remove_from_list;
1311
1312 status = gpiochip_irqchip_init_valid_mask(chip);
1313 if (status)
1314 goto err_remove_from_list;
1315
1316 status = gpiochip_init_valid_mask(chip);
1317 if (status)
1318 goto err_remove_irqchip_mask;
1319
1320 status = gpiochip_add_irqchip(chip, lock_key, request_key);
1321 if (status)
1322 goto err_remove_chip;
1323
1324 status = of_gpiochip_add(chip);
1325 if (status)
1326 goto err_remove_chip;
1327
1328 acpi_gpiochip_add(chip);
1329
1330 /*
1331 * By first adding the chardev, and then adding the device,
1332 * we get a device node entry in sysfs under
1333 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1334 * coldplug of device nodes and other udev business.
1335 * We can do this only if gpiolib has been initialized.
1336 * Otherwise, defer until later.
1337 */
1338 if (gpiolib_initialized) {
1339 status = gpiochip_setup_dev(gdev);
1340 if (status)
1341 goto err_remove_chip;
1342 }
1343 return 0;
1344
1345err_remove_chip:
1346 acpi_gpiochip_remove(chip);
1347 gpiochip_free_hogs(chip);
1348 of_gpiochip_remove(chip);
1349 gpiochip_free_valid_mask(chip);
1350err_remove_irqchip_mask:
1351 gpiochip_irqchip_free_valid_mask(chip);
1352err_remove_from_list:
1353 spin_lock_irqsave(&gpio_lock, flags);
1354 list_del(&gdev->list);
1355 spin_unlock_irqrestore(&gpio_lock, flags);
1356err_free_label:
1357 kfree_const(gdev->label);
1358err_free_descs:
1359 kfree(gdev->descs);
1360err_free_gdev:
1361 ida_simple_remove(&gpio_ida, gdev->id);
1362 /* failures here can mean systems won't boot... */
1363 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
1364 gdev->base, gdev->base + gdev->ngpio - 1,
1365 chip->label ? : "generic");
1366 kfree(gdev);
1367 return status;
1368}
1369EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1370
1371/**
1372 * gpiochip_get_data() - get per-subdriver data for the chip
1373 * @chip: GPIO chip
1374 *
1375 * Returns:
1376 * The per-subdriver data for the chip.
1377 */
1378void *gpiochip_get_data(struct gpio_chip *chip)
1379{
1380 return chip->gpiodev->data;
1381}
1382EXPORT_SYMBOL_GPL(gpiochip_get_data);
1383
1384/**
1385 * gpiochip_remove() - unregister a gpio_chip
1386 * @chip: the chip to unregister
1387 *
1388 * A gpio_chip with any GPIOs still requested may not be removed.
1389 */
1390void gpiochip_remove(struct gpio_chip *chip)
1391{
1392 struct gpio_device *gdev = chip->gpiodev;
1393 struct gpio_desc *desc;
1394 unsigned long flags;
1395 unsigned i;
1396 bool requested = false;
1397
1398 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1399 gpiochip_sysfs_unregister(gdev);
1400 gpiochip_free_hogs(chip);
1401 /* Numb the device, cancelling all outstanding operations */
1402 gdev->chip = NULL;
1403 gpiochip_irqchip_remove(chip);
1404 acpi_gpiochip_remove(chip);
1405 gpiochip_remove_pin_ranges(chip);
1406 of_gpiochip_remove(chip);
1407 gpiochip_free_valid_mask(chip);
1408 /*
1409 * We accept no more calls into the driver from this point, so
1410 * NULL the driver data pointer
1411 */
1412 gdev->data = NULL;
1413
1414 spin_lock_irqsave(&gpio_lock, flags);
1415 for (i = 0; i < gdev->ngpio; i++) {
1416 desc = &gdev->descs[i];
1417 if (test_bit(FLAG_REQUESTED, &desc->flags))
1418 requested = true;
1419 }
1420 spin_unlock_irqrestore(&gpio_lock, flags);
1421
1422 if (requested)
1423 dev_crit(&gdev->dev,
1424 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1425
1426 /*
1427 * The gpiochip side puts its use of the device to rest here:
1428 * if there are no userspace clients, the chardev and device will
1429 * be removed, else it will be dangling until the last user is
1430 * gone.
1431 */
1432 cdev_device_del(&gdev->chrdev, &gdev->dev);
1433 put_device(&gdev->dev);
1434}
1435EXPORT_SYMBOL_GPL(gpiochip_remove);
1436
1437static void devm_gpio_chip_release(struct device *dev, void *res)
1438{
1439 struct gpio_chip *chip = *(struct gpio_chip **)res;
1440
1441 gpiochip_remove(chip);
1442}
1443
1444static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
1445
1446{
1447 struct gpio_chip **r = res;
1448
1449 if (!r || !*r) {
1450 WARN_ON(!r || !*r);
1451 return 0;
1452 }
1453
1454 return *r == data;
1455}
1456
1457/**
1458 * devm_gpiochip_add_data() - Resource manager gpiochip_add_data()
1459 * @dev: the device pointer on which irq_chip belongs to.
1460 * @chip: the chip to register, with chip->base initialized
1461 * @data: driver-private data associated with this chip
1462 *
1463 * Context: potentially before irqs will work
1464 *
1465 * The gpio chip automatically be released when the device is unbound.
1466 *
1467 * Returns:
1468 * A negative errno if the chip can't be registered, such as because the
1469 * chip->base is invalid or already associated with a different chip.
1470 * Otherwise it returns zero as a success code.
1471 */
1472int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1473 void *data)
1474{
1475 struct gpio_chip **ptr;
1476 int ret;
1477
1478 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1479 GFP_KERNEL);
1480 if (!ptr)
1481 return -ENOMEM;
1482
1483 ret = gpiochip_add_data(chip, data);
1484 if (ret < 0) {
1485 devres_free(ptr);
1486 return ret;
1487 }
1488
1489 *ptr = chip;
1490 devres_add(dev, ptr);
1491
1492 return 0;
1493}
1494EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1495
1496/**
1497 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1498 * @dev: device for which which resource was allocated
1499 * @chip: the chip to remove
1500 *
1501 * A gpio_chip with any GPIOs still requested may not be removed.
1502 */
1503void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
1504{
1505 int ret;
1506
1507 ret = devres_release(dev, devm_gpio_chip_release,
1508 devm_gpio_chip_match, chip);
1509 WARN_ON(ret);
1510}
1511EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
1512
1513/**
1514 * gpiochip_find() - iterator for locating a specific gpio_chip
1515 * @data: data to pass to match function
1516 * @match: Callback function to check gpio_chip
1517 *
1518 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1519 * determined by a user supplied @match callback. The callback should return
1520 * 0 if the device doesn't match and non-zero if it does. If the callback is
1521 * non-zero, this function will return to the caller and not iterate over any
1522 * more gpio_chips.
1523 */
1524struct gpio_chip *gpiochip_find(void *data,
1525 int (*match)(struct gpio_chip *chip,
1526 void *data))
1527{
1528 struct gpio_device *gdev;
1529 struct gpio_chip *chip = NULL;
1530 unsigned long flags;
1531
1532 spin_lock_irqsave(&gpio_lock, flags);
1533 list_for_each_entry(gdev, &gpio_devices, list)
1534 if (gdev->chip && match(gdev->chip, data)) {
1535 chip = gdev->chip;
1536 break;
1537 }
1538
1539 spin_unlock_irqrestore(&gpio_lock, flags);
1540
1541 return chip;
1542}
1543EXPORT_SYMBOL_GPL(gpiochip_find);
1544
1545static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1546{
1547 const char *name = data;
1548
1549 return !strcmp(chip->label, name);
1550}
1551
1552static struct gpio_chip *find_chip_by_name(const char *name)
1553{
1554 return gpiochip_find((void *)name, gpiochip_match_name);
1555}
1556
1557#ifdef CONFIG_GPIOLIB_IRQCHIP
1558
1559/*
1560 * The following is irqchip helper code for gpiochips.
1561 */
1562
1563static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1564{
1565 if (!gpiochip->irq.need_valid_mask)
1566 return 0;
1567
1568 gpiochip->irq.valid_mask = gpiochip_allocate_mask(gpiochip);
1569 if (!gpiochip->irq.valid_mask)
1570 return -ENOMEM;
1571
1572 return 0;
1573}
1574
1575static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1576{
1577 kfree(gpiochip->irq.valid_mask);
1578 gpiochip->irq.valid_mask = NULL;
1579}
1580
1581bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1582 unsigned int offset)
1583{
1584 if (!gpiochip_line_is_valid(gpiochip, offset))
1585 return false;
1586 /* No mask means all valid */
1587 if (likely(!gpiochip->irq.valid_mask))
1588 return true;
1589 return test_bit(offset, gpiochip->irq.valid_mask);
1590}
1591EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1592
1593/**
1594 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1595 * @gpiochip: the gpiochip to set the irqchip chain to
1596 * @irqchip: the irqchip to chain to the gpiochip
1597 * @parent_irq: the irq number corresponding to the parent IRQ for this
1598 * chained irqchip
1599 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1600 * coming out of the gpiochip. If the interrupt is nested rather than
1601 * cascaded, pass NULL in this handler argument
1602 */
1603static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
1604 struct irq_chip *irqchip,
1605 unsigned int parent_irq,
1606 irq_flow_handler_t parent_handler)
1607{
1608 unsigned int offset;
1609
1610 if (!gpiochip->irq.domain) {
1611 chip_err(gpiochip, "called %s before setting up irqchip\n",
1612 __func__);
1613 return;
1614 }
1615
1616 if (parent_handler) {
1617 if (gpiochip->can_sleep) {
1618 chip_err(gpiochip,
1619 "you cannot have chained interrupts on a "
1620 "chip that may sleep\n");
1621 return;
1622 }
1623 /*
1624 * The parent irqchip is already using the chip_data for this
1625 * irqchip, so our callbacks simply use the handler_data.
1626 */
1627 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1628 gpiochip);
1629
1630 gpiochip->irq.parents = &parent_irq;
1631 gpiochip->irq.num_parents = 1;
1632 }
1633
1634 /* Set the parent IRQ for all affected IRQs */
1635 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1636 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1637 continue;
1638 irq_set_parent(irq_find_mapping(gpiochip->irq.domain, offset),
1639 parent_irq);
1640 }
1641}
1642
1643/**
1644 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1645 * @gpiochip: the gpiochip to set the irqchip chain to
1646 * @irqchip: the irqchip to chain to the gpiochip
1647 * @parent_irq: the irq number corresponding to the parent IRQ for this
1648 * chained irqchip
1649 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1650 * coming out of the gpiochip. If the interrupt is nested rather than
1651 * cascaded, pass NULL in this handler argument
1652 */
1653void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1654 struct irq_chip *irqchip,
1655 unsigned int parent_irq,
1656 irq_flow_handler_t parent_handler)
1657{
1658 if (gpiochip->irq.threaded) {
1659 chip_err(gpiochip, "tried to chain a threaded gpiochip\n");
1660 return;
1661 }
1662
1663 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1664 parent_handler);
1665}
1666EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1667
1668/**
1669 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1670 * @gpiochip: the gpiochip to set the irqchip nested handler to
1671 * @irqchip: the irqchip to nest to the gpiochip
1672 * @parent_irq: the irq number corresponding to the parent IRQ for this
1673 * nested irqchip
1674 */
1675void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1676 struct irq_chip *irqchip,
1677 unsigned int parent_irq)
1678{
1679 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1680 NULL);
1681}
1682EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1683
1684/**
1685 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1686 * @d: the irqdomain used by this irqchip
1687 * @irq: the global irq number used by this GPIO irqchip irq
1688 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1689 *
1690 * This function will set up the mapping for a certain IRQ line on a
1691 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1692 * stored inside the gpiochip.
1693 */
1694int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1695 irq_hw_number_t hwirq)
1696{
1697 struct gpio_chip *chip = d->host_data;
1698 int err = 0;
1699
1700 if (!gpiochip_irqchip_irq_valid(chip, hwirq))
1701 return -ENXIO;
1702
1703 irq_set_chip_data(irq, chip);
1704 /*
1705 * This lock class tells lockdep that GPIO irqs are in a different
1706 * category than their parents, so it won't report false recursion.
1707 */
1708 irq_set_lockdep_class(irq, chip->irq.lock_key, chip->irq.request_key);
1709 irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
1710 /* Chips that use nested thread handlers have them marked */
1711 if (chip->irq.threaded)
1712 irq_set_nested_thread(irq, 1);
1713 irq_set_noprobe(irq);
1714
1715 if (chip->irq.num_parents == 1)
1716 err = irq_set_parent(irq, chip->irq.parents[0]);
1717 else if (chip->irq.map)
1718 err = irq_set_parent(irq, chip->irq.map[hwirq]);
1719
1720 if (err < 0)
1721 return err;
1722
1723 /*
1724 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1725 * is passed as default type.
1726 */
1727 if (chip->irq.default_type != IRQ_TYPE_NONE)
1728 irq_set_irq_type(irq, chip->irq.default_type);
1729
1730 return 0;
1731}
1732EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1733
1734void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1735{
1736 struct gpio_chip *chip = d->host_data;
1737
1738 if (chip->irq.threaded)
1739 irq_set_nested_thread(irq, 0);
1740 irq_set_chip_and_handler(irq, NULL, NULL);
1741 irq_set_chip_data(irq, NULL);
1742}
1743EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1744
1745static const struct irq_domain_ops gpiochip_domain_ops = {
1746 .map = gpiochip_irq_map,
1747 .unmap = gpiochip_irq_unmap,
1748 /* Virtually all GPIO irqchips are twocell:ed */
1749 .xlate = irq_domain_xlate_twocell,
1750};
1751
1752static int gpiochip_irq_reqres(struct irq_data *d)
1753{
1754 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1755
1756 if (!try_module_get(chip->gpiodev->owner))
1757 return -ENODEV;
1758
1759 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
1760 chip_err(chip,
1761 "unable to lock HW IRQ %lu for IRQ\n",
1762 d->hwirq);
1763 module_put(chip->gpiodev->owner);
1764 return -EINVAL;
1765 }
1766 return 0;
1767}
1768
1769static void gpiochip_irq_relres(struct irq_data *d)
1770{
1771 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1772
1773 gpiochip_unlock_as_irq(chip, d->hwirq);
1774 module_put(chip->gpiodev->owner);
1775}
1776
1777static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1778{
1779 if (!gpiochip_irqchip_irq_valid(chip, offset))
1780 return -ENXIO;
1781
1782 return irq_create_mapping(chip->irq.domain, offset);
1783}
1784
1785/**
1786 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1787 * @gpiochip: the GPIO chip to add the IRQ chip to
1788 * @lock_key: lockdep class for IRQ lock
1789 * @request_key: lockdep class for IRQ request
1790 */
1791static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
1792 struct lock_class_key *lock_key,
1793 struct lock_class_key *request_key)
1794{
1795 struct irq_chip *irqchip = gpiochip->irq.chip;
1796 const struct irq_domain_ops *ops;
1797 struct device_node *np;
1798 unsigned int type;
1799 unsigned int i;
1800
1801 if (!irqchip)
1802 return 0;
1803
1804 if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {
1805 chip_err(gpiochip, "you cannot have chained interrupts on a "
1806 "chip that may sleep\n");
1807 return -EINVAL;
1808 }
1809
1810 np = gpiochip->gpiodev->dev.of_node;
1811 type = gpiochip->irq.default_type;
1812
1813 /*
1814 * Specifying a default trigger is a terrible idea if DT or ACPI is
1815 * used to configure the interrupts, as you may end up with
1816 * conflicting triggers. Tell the user, and reset to NONE.
1817 */
1818 if (WARN(np && type != IRQ_TYPE_NONE,
1819 "%s: Ignoring %u default trigger\n", np->full_name, type))
1820 type = IRQ_TYPE_NONE;
1821
1822 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1823 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1824 "Ignoring %u default trigger\n", type);
1825 type = IRQ_TYPE_NONE;
1826 }
1827
1828 gpiochip->to_irq = gpiochip_to_irq;
1829 gpiochip->irq.default_type = type;
1830 gpiochip->irq.lock_key = lock_key;
1831 gpiochip->irq.request_key = request_key;
1832
1833 if (gpiochip->irq.domain_ops)
1834 ops = gpiochip->irq.domain_ops;
1835 else
1836 ops = &gpiochip_domain_ops;
1837
1838 gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
1839 gpiochip->irq.first,
1840 ops, gpiochip);
1841 if (!gpiochip->irq.domain)
1842 return -EINVAL;
1843
1844 /*
1845 * It is possible for a driver to override this, but only if the
1846 * alternative functions are both implemented.
1847 */
1848 if (!irqchip->irq_request_resources &&
1849 !irqchip->irq_release_resources) {
1850 irqchip->irq_request_resources = gpiochip_irq_reqres;
1851 irqchip->irq_release_resources = gpiochip_irq_relres;
1852 }
1853
1854 if (gpiochip->irq.parent_handler) {
1855 void *data = gpiochip->irq.parent_handler_data ?: gpiochip;
1856
1857 for (i = 0; i < gpiochip->irq.num_parents; i++) {
1858 /*
1859 * The parent IRQ chip is already using the chip_data
1860 * for this IRQ chip, so our callbacks simply use the
1861 * handler_data.
1862 */
1863 irq_set_chained_handler_and_data(gpiochip->irq.parents[i],
1864 gpiochip->irq.parent_handler,
1865 data);
1866 }
1867 }
1868
1869 acpi_gpiochip_request_interrupts(gpiochip);
1870
1871 return 0;
1872}
1873
1874/**
1875 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1876 * @gpiochip: the gpiochip to remove the irqchip from
1877 *
1878 * This is called only from gpiochip_remove()
1879 */
1880static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1881{
1882 unsigned int offset;
1883
1884 acpi_gpiochip_free_interrupts(gpiochip);
1885
1886 if (gpiochip->irq.chip && gpiochip->irq.parent_handler) {
1887 struct gpio_irq_chip *irq = &gpiochip->irq;
1888 unsigned int i;
1889
1890 for (i = 0; i < irq->num_parents; i++)
1891 irq_set_chained_handler_and_data(irq->parents[i],
1892 NULL, NULL);
1893 }
1894
1895 /* Remove all IRQ mappings and delete the domain */
1896 if (gpiochip->irq.domain) {
1897 unsigned int irq;
1898
1899 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1900 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1901 continue;
1902
1903 irq = irq_find_mapping(gpiochip->irq.domain, offset);
1904 irq_dispose_mapping(irq);
1905 }
1906
1907 irq_domain_remove(gpiochip->irq.domain);
1908 }
1909
1910 if (gpiochip->irq.chip) {
1911 gpiochip->irq.chip->irq_request_resources = NULL;
1912 gpiochip->irq.chip->irq_release_resources = NULL;
1913 gpiochip->irq.chip = NULL;
1914 }
1915
1916 gpiochip_irqchip_free_valid_mask(gpiochip);
1917}
1918
1919/**
1920 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
1921 * @gpiochip: the gpiochip to add the irqchip to
1922 * @irqchip: the irqchip to add to the gpiochip
1923 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1924 * allocate gpiochip irqs from
1925 * @handler: the irq handler to use (often a predefined irq core function)
1926 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1927 * to have the core avoid setting up any default type in the hardware.
1928 * @threaded: whether this irqchip uses a nested thread handler
1929 * @lock_key: lockdep class for IRQ lock
1930 * @request_key: lockdep class for IRQ request
1931 *
1932 * This function closely associates a certain irqchip with a certain
1933 * gpiochip, providing an irq domain to translate the local IRQs to
1934 * global irqs in the gpiolib core, and making sure that the gpiochip
1935 * is passed as chip data to all related functions. Driver callbacks
1936 * need to use gpiochip_get_data() to get their local state containers back
1937 * from the gpiochip passed as chip data. An irqdomain will be stored
1938 * in the gpiochip that shall be used by the driver to handle IRQ number
1939 * translation. The gpiochip will need to be initialized and registered
1940 * before calling this function.
1941 *
1942 * This function will handle two cell:ed simple IRQs and assumes all
1943 * the pins on the gpiochip can generate a unique IRQ. Everything else
1944 * need to be open coded.
1945 */
1946int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
1947 struct irq_chip *irqchip,
1948 unsigned int first_irq,
1949 irq_flow_handler_t handler,
1950 unsigned int type,
1951 bool threaded,
1952 struct lock_class_key *lock_key,
1953 struct lock_class_key *request_key)
1954{
1955 struct device_node *of_node;
1956
1957 if (!gpiochip || !irqchip)
1958 return -EINVAL;
1959
1960 if (!gpiochip->parent) {
1961 pr_err("missing gpiochip .dev parent pointer\n");
1962 return -EINVAL;
1963 }
1964 gpiochip->irq.threaded = threaded;
1965 of_node = gpiochip->parent->of_node;
1966#ifdef CONFIG_OF_GPIO
1967 /*
1968 * If the gpiochip has an assigned OF node this takes precedence
1969 * FIXME: get rid of this and use gpiochip->parent->of_node
1970 * everywhere
1971 */
1972 if (gpiochip->of_node)
1973 of_node = gpiochip->of_node;
1974#endif
1975 /*
1976 * Specifying a default trigger is a terrible idea if DT or ACPI is
1977 * used to configure the interrupts, as you may end-up with
1978 * conflicting triggers. Tell the user, and reset to NONE.
1979 */
1980 if (WARN(of_node && type != IRQ_TYPE_NONE,
1981 "%pOF: Ignoring %d default trigger\n", of_node, type))
1982 type = IRQ_TYPE_NONE;
1983 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1984 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1985 "Ignoring %d default trigger\n", type);
1986 type = IRQ_TYPE_NONE;
1987 }
1988
1989 gpiochip->irq.chip = irqchip;
1990 gpiochip->irq.handler = handler;
1991 gpiochip->irq.default_type = type;
1992 gpiochip->to_irq = gpiochip_to_irq;
1993 gpiochip->irq.lock_key = lock_key;
1994 gpiochip->irq.request_key = request_key;
1995 gpiochip->irq.domain = irq_domain_add_simple(of_node,
1996 gpiochip->ngpio, first_irq,
1997 &gpiochip_domain_ops, gpiochip);
1998 if (!gpiochip->irq.domain) {
1999 gpiochip->irq.chip = NULL;
2000 return -EINVAL;
2001 }
2002
2003 /*
2004 * It is possible for a driver to override this, but only if the
2005 * alternative functions are both implemented.
2006 */
2007 if (!irqchip->irq_request_resources &&
2008 !irqchip->irq_release_resources) {
2009 irqchip->irq_request_resources = gpiochip_irq_reqres;
2010 irqchip->irq_release_resources = gpiochip_irq_relres;
2011 }
2012
2013 acpi_gpiochip_request_interrupts(gpiochip);
2014
2015 return 0;
2016}
2017EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
2018
2019#else /* CONFIG_GPIOLIB_IRQCHIP */
2020
2021static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
2022 struct lock_class_key *lock_key,
2023 struct lock_class_key *request_key)
2024{
2025 return 0;
2026}
2027
2028static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
2029static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
2030{
2031 return 0;
2032}
2033static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
2034{ }
2035
2036#endif /* CONFIG_GPIOLIB_IRQCHIP */
2037
2038/**
2039 * gpiochip_generic_request() - request the gpio function for a pin
2040 * @chip: the gpiochip owning the GPIO
2041 * @offset: the offset of the GPIO to request for GPIO function
2042 */
2043int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
2044{
2045 return pinctrl_gpio_request(chip->gpiodev->base + offset);
2046}
2047EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2048
2049/**
2050 * gpiochip_generic_free() - free the gpio function from a pin
2051 * @chip: the gpiochip to request the gpio function for
2052 * @offset: the offset of the GPIO to free from GPIO function
2053 */
2054void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
2055{
2056 pinctrl_gpio_free(chip->gpiodev->base + offset);
2057}
2058EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2059
2060/**
2061 * gpiochip_generic_config() - apply configuration for a pin
2062 * @chip: the gpiochip owning the GPIO
2063 * @offset: the offset of the GPIO to apply the configuration
2064 * @config: the configuration to be applied
2065 */
2066int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
2067 unsigned long config)
2068{
2069 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
2070}
2071EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2072
2073#ifdef CONFIG_PINCTRL
2074
2075/**
2076 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2077 * @chip: the gpiochip to add the range for
2078 * @pctldev: the pin controller to map to
2079 * @gpio_offset: the start offset in the current gpio_chip number space
2080 * @pin_group: name of the pin group inside the pin controller
2081 */
2082int gpiochip_add_pingroup_range(struct gpio_chip *chip,
2083 struct pinctrl_dev *pctldev,
2084 unsigned int gpio_offset, const char *pin_group)
2085{
2086 struct gpio_pin_range *pin_range;
2087 struct gpio_device *gdev = chip->gpiodev;
2088 int ret;
2089
2090 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2091 if (!pin_range) {
2092 chip_err(chip, "failed to allocate pin ranges\n");
2093 return -ENOMEM;
2094 }
2095
2096 /* Use local offset as range ID */
2097 pin_range->range.id = gpio_offset;
2098 pin_range->range.gc = chip;
2099 pin_range->range.name = chip->label;
2100 pin_range->range.base = gdev->base + gpio_offset;
2101 pin_range->pctldev = pctldev;
2102
2103 ret = pinctrl_get_group_pins(pctldev, pin_group,
2104 &pin_range->range.pins,
2105 &pin_range->range.npins);
2106 if (ret < 0) {
2107 kfree(pin_range);
2108 return ret;
2109 }
2110
2111 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2112
2113 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2114 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2115 pinctrl_dev_get_devname(pctldev), pin_group);
2116
2117 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2118
2119 return 0;
2120}
2121EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2122
2123/**
2124 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2125 * @chip: the gpiochip to add the range for
2126 * @pinctl_name: the dev_name() of the pin controller to map to
2127 * @gpio_offset: the start offset in the current gpio_chip number space
2128 * @pin_offset: the start offset in the pin controller number space
2129 * @npins: the number of pins from the offset of each pin space (GPIO and
2130 * pin controller) to accumulate in this range
2131 *
2132 * Returns:
2133 * 0 on success, or a negative error-code on failure.
2134 */
2135int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
2136 unsigned int gpio_offset, unsigned int pin_offset,
2137 unsigned int npins)
2138{
2139 struct gpio_pin_range *pin_range;
2140 struct gpio_device *gdev = chip->gpiodev;
2141 int ret;
2142
2143 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2144 if (!pin_range) {
2145 chip_err(chip, "failed to allocate pin ranges\n");
2146 return -ENOMEM;
2147 }
2148
2149 /* Use local offset as range ID */
2150 pin_range->range.id = gpio_offset;
2151 pin_range->range.gc = chip;
2152 pin_range->range.name = chip->label;
2153 pin_range->range.base = gdev->base + gpio_offset;
2154 pin_range->range.pin_base = pin_offset;
2155 pin_range->range.npins = npins;
2156 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2157 &pin_range->range);
2158 if (IS_ERR(pin_range->pctldev)) {
2159 ret = PTR_ERR(pin_range->pctldev);
2160 chip_err(chip, "could not create pin range\n");
2161 kfree(pin_range);
2162 return ret;
2163 }
2164 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2165 gpio_offset, gpio_offset + npins - 1,
2166 pinctl_name,
2167 pin_offset, pin_offset + npins - 1);
2168
2169 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2170
2171 return 0;
2172}
2173EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2174
2175/**
2176 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2177 * @chip: the chip to remove all the mappings for
2178 */
2179void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
2180{
2181 struct gpio_pin_range *pin_range, *tmp;
2182 struct gpio_device *gdev = chip->gpiodev;
2183
2184 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2185 list_del(&pin_range->node);
2186 pinctrl_remove_gpio_range(pin_range->pctldev,
2187 &pin_range->range);
2188 kfree(pin_range);
2189 }
2190}
2191EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2192
2193#endif /* CONFIG_PINCTRL */
2194
2195/* These "optional" allocation calls help prevent drivers from stomping
2196 * on each other, and help provide better diagnostics in debugfs.
2197 * They're called even less than the "set direction" calls.
2198 */
2199static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2200{
2201 struct gpio_chip *chip = desc->gdev->chip;
2202 int status;
2203 unsigned long flags;
2204
2205 spin_lock_irqsave(&gpio_lock, flags);
2206
2207 /* NOTE: gpio_request() can be called in early boot,
2208 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2209 */
2210
2211 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2212 desc_set_label(desc, label ? : "?");
2213 status = 0;
2214 } else {
2215 status = -EBUSY;
2216 goto done;
2217 }
2218
2219 if (chip->request) {
2220 /* chip->request may sleep */
2221 spin_unlock_irqrestore(&gpio_lock, flags);
2222 status = chip->request(chip, gpio_chip_hwgpio(desc));
2223 spin_lock_irqsave(&gpio_lock, flags);
2224
2225 if (status < 0) {
2226 desc_set_label(desc, NULL);
2227 clear_bit(FLAG_REQUESTED, &desc->flags);
2228 goto done;
2229 }
2230 }
2231 if (chip->get_direction) {
2232 /* chip->get_direction may sleep */
2233 spin_unlock_irqrestore(&gpio_lock, flags);
2234 gpiod_get_direction(desc);
2235 spin_lock_irqsave(&gpio_lock, flags);
2236 }
2237done:
2238 spin_unlock_irqrestore(&gpio_lock, flags);
2239 return status;
2240}
2241
2242/*
2243 * This descriptor validation needs to be inserted verbatim into each
2244 * function taking a descriptor, so we need to use a preprocessor
2245 * macro to avoid endless duplication. If the desc is NULL it is an
2246 * optional GPIO and calls should just bail out.
2247 */
2248static int validate_desc(const struct gpio_desc *desc, const char *func)
2249{
2250 if (!desc)
2251 return 0;
2252 if (IS_ERR(desc)) {
2253 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2254 return PTR_ERR(desc);
2255 }
2256 if (!desc->gdev) {
2257 pr_warn("%s: invalid GPIO (no device)\n", func);
2258 return -EINVAL;
2259 }
2260 if (!desc->gdev->chip) {
2261 dev_warn(&desc->gdev->dev,
2262 "%s: backing chip is gone\n", func);
2263 return 0;
2264 }
2265 return 1;
2266}
2267
2268#define VALIDATE_DESC(desc) do { \
2269 int __valid = validate_desc(desc, __func__); \
2270 if (__valid <= 0) \
2271 return __valid; \
2272 } while (0)
2273
2274#define VALIDATE_DESC_VOID(desc) do { \
2275 int __valid = validate_desc(desc, __func__); \
2276 if (__valid <= 0) \
2277 return; \
2278 } while (0)
2279
2280int gpiod_request(struct gpio_desc *desc, const char *label)
2281{
2282 int status = -EPROBE_DEFER;
2283 struct gpio_device *gdev;
2284
2285 VALIDATE_DESC(desc);
2286 gdev = desc->gdev;
2287
2288 if (try_module_get(gdev->owner)) {
2289 status = gpiod_request_commit(desc, label);
2290 if (status < 0)
2291 module_put(gdev->owner);
2292 else
2293 get_device(&gdev->dev);
2294 }
2295
2296 if (status)
2297 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2298
2299 return status;
2300}
2301
2302static bool gpiod_free_commit(struct gpio_desc *desc)
2303{
2304 bool ret = false;
2305 unsigned long flags;
2306 struct gpio_chip *chip;
2307
2308 might_sleep();
2309
2310 gpiod_unexport(desc);
2311
2312 spin_lock_irqsave(&gpio_lock, flags);
2313
2314 chip = desc->gdev->chip;
2315 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2316 if (chip->free) {
2317 spin_unlock_irqrestore(&gpio_lock, flags);
2318 might_sleep_if(chip->can_sleep);
2319 chip->free(chip, gpio_chip_hwgpio(desc));
2320 spin_lock_irqsave(&gpio_lock, flags);
2321 }
2322 desc_set_label(desc, NULL);
2323 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2324 clear_bit(FLAG_REQUESTED, &desc->flags);
2325 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2326 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2327 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2328 ret = true;
2329 }
2330
2331 spin_unlock_irqrestore(&gpio_lock, flags);
2332 return ret;
2333}
2334
2335void gpiod_free(struct gpio_desc *desc)
2336{
2337 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2338 module_put(desc->gdev->owner);
2339 put_device(&desc->gdev->dev);
2340 } else {
2341 WARN_ON(extra_checks);
2342 }
2343}
2344
2345/**
2346 * gpiochip_is_requested - return string iff signal was requested
2347 * @chip: controller managing the signal
2348 * @offset: of signal within controller's 0..(ngpio - 1) range
2349 *
2350 * Returns NULL if the GPIO is not currently requested, else a string.
2351 * The string returned is the label passed to gpio_request(); if none has been
2352 * passed it is a meaningless, non-NULL constant.
2353 *
2354 * This function is for use by GPIO controller drivers. The label can
2355 * help with diagnostics, and knowing that the signal is used as a GPIO
2356 * can help avoid accidentally multiplexing it to another controller.
2357 */
2358const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2359{
2360 struct gpio_desc *desc;
2361
2362 if (offset >= chip->ngpio)
2363 return NULL;
2364
2365 desc = &chip->gpiodev->descs[offset];
2366
2367 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2368 return NULL;
2369 return desc->label;
2370}
2371EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2372
2373/**
2374 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2375 * @chip: GPIO chip
2376 * @hwnum: hardware number of the GPIO for which to request the descriptor
2377 * @label: label for the GPIO
2378 *
2379 * Function allows GPIO chip drivers to request and use their own GPIO
2380 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2381 * function will not increase reference count of the GPIO chip module. This
2382 * allows the GPIO chip module to be unloaded as needed (we assume that the
2383 * GPIO chip driver handles freeing the GPIOs it has requested).
2384 *
2385 * Returns:
2386 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2387 * code on failure.
2388 */
2389struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2390 const char *label)
2391{
2392 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2393 int err;
2394
2395 if (IS_ERR(desc)) {
2396 chip_err(chip, "failed to get GPIO descriptor\n");
2397 return desc;
2398 }
2399
2400 err = gpiod_request_commit(desc, label);
2401 if (err < 0)
2402 return ERR_PTR(err);
2403
2404 return desc;
2405}
2406EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2407
2408/**
2409 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2410 * @desc: GPIO descriptor to free
2411 *
2412 * Function frees the given GPIO requested previously with
2413 * gpiochip_request_own_desc().
2414 */
2415void gpiochip_free_own_desc(struct gpio_desc *desc)
2416{
2417 if (desc)
2418 gpiod_free_commit(desc);
2419}
2420EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2421
2422/*
2423 * Drivers MUST set GPIO direction before making get/set calls. In
2424 * some cases this is done in early boot, before IRQs are enabled.
2425 *
2426 * As a rule these aren't called more than once (except for drivers
2427 * using the open-drain emulation idiom) so these are natural places
2428 * to accumulate extra debugging checks. Note that we can't (yet)
2429 * rely on gpio_request() having been called beforehand.
2430 */
2431
2432/**
2433 * gpiod_direction_input - set the GPIO direction to input
2434 * @desc: GPIO to set to input
2435 *
2436 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2437 * be called safely on it.
2438 *
2439 * Return 0 in case of success, else an error code.
2440 */
2441int gpiod_direction_input(struct gpio_desc *desc)
2442{
2443 struct gpio_chip *chip;
2444 int status = -EINVAL;
2445
2446 VALIDATE_DESC(desc);
2447 chip = desc->gdev->chip;
2448
2449 if (!chip->get || !chip->direction_input) {
2450 gpiod_warn(desc,
2451 "%s: missing get() or direction_input() operations\n",
2452 __func__);
2453 return -EIO;
2454 }
2455
2456 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2457 if (status == 0)
2458 clear_bit(FLAG_IS_OUT, &desc->flags);
2459
2460 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2461
2462 return status;
2463}
2464EXPORT_SYMBOL_GPL(gpiod_direction_input);
2465
2466static int gpio_set_drive_single_ended(struct gpio_chip *gc, unsigned offset,
2467 enum pin_config_param mode)
2468{
2469 unsigned long config = { PIN_CONF_PACKED(mode, 0) };
2470
2471 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2472}
2473
2474static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2475{
2476 struct gpio_chip *gc = desc->gdev->chip;
2477 int val = !!value;
2478 int ret;
2479
2480 if (!gc->set || !gc->direction_output) {
2481 gpiod_warn(desc,
2482 "%s: missing set() or direction_output() operations\n",
2483 __func__);
2484 return -EIO;
2485 }
2486
2487 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2488 if (!ret)
2489 set_bit(FLAG_IS_OUT, &desc->flags);
2490 trace_gpio_value(desc_to_gpio(desc), 0, val);
2491 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2492 return ret;
2493}
2494
2495/**
2496 * gpiod_direction_output_raw - set the GPIO direction to output
2497 * @desc: GPIO to set to output
2498 * @value: initial output value of the GPIO
2499 *
2500 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2501 * be called safely on it. The initial value of the output must be specified
2502 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2503 *
2504 * Return 0 in case of success, else an error code.
2505 */
2506int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2507{
2508 VALIDATE_DESC(desc);
2509 return gpiod_direction_output_raw_commit(desc, value);
2510}
2511EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2512
2513/**
2514 * gpiod_direction_output - set the GPIO direction to output
2515 * @desc: GPIO to set to output
2516 * @value: initial output value of the GPIO
2517 *
2518 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2519 * be called safely on it. The initial value of the output must be specified
2520 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2521 * account.
2522 *
2523 * Return 0 in case of success, else an error code.
2524 */
2525int gpiod_direction_output(struct gpio_desc *desc, int value)
2526{
2527 struct gpio_chip *gc;
2528 int ret;
2529
2530 VALIDATE_DESC(desc);
2531 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2532 value = !value;
2533 else
2534 value = !!value;
2535
2536 /* GPIOs used for IRQs shall not be set as output */
2537 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
2538 gpiod_err(desc,
2539 "%s: tried to set a GPIO tied to an IRQ as output\n",
2540 __func__);
2541 return -EIO;
2542 }
2543
2544 gc = desc->gdev->chip;
2545 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2546 /* First see if we can enable open drain in hardware */
2547 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2548 PIN_CONFIG_DRIVE_OPEN_DRAIN);
2549 if (!ret)
2550 goto set_output_value;
2551 /* Emulate open drain by not actively driving the line high */
2552 if (value)
2553 return gpiod_direction_input(desc);
2554 }
2555 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2556 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2557 PIN_CONFIG_DRIVE_OPEN_SOURCE);
2558 if (!ret)
2559 goto set_output_value;
2560 /* Emulate open source by not actively driving the line low */
2561 if (!value)
2562 return gpiod_direction_input(desc);
2563 } else {
2564 gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2565 PIN_CONFIG_DRIVE_PUSH_PULL);
2566 }
2567
2568set_output_value:
2569 return gpiod_direction_output_raw_commit(desc, value);
2570}
2571EXPORT_SYMBOL_GPL(gpiod_direction_output);
2572
2573/**
2574 * gpiod_set_debounce - sets @debounce time for a GPIO
2575 * @desc: descriptor of the GPIO for which to set debounce time
2576 * @debounce: debounce time in microseconds
2577 *
2578 * Returns:
2579 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2580 * debounce time.
2581 */
2582int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2583{
2584 struct gpio_chip *chip;
2585 unsigned long config;
2586
2587 VALIDATE_DESC(desc);
2588 chip = desc->gdev->chip;
2589 if (!chip->set || !chip->set_config) {
2590 gpiod_dbg(desc,
2591 "%s: missing set() or set_config() operations\n",
2592 __func__);
2593 return -ENOTSUPP;
2594 }
2595
2596 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2597 return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
2598}
2599EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2600
2601/**
2602 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2603 * @desc: descriptor of the GPIO for which to configure persistence
2604 * @transitory: True to lose state on suspend or reset, false for persistence
2605 *
2606 * Returns:
2607 * 0 on success, otherwise a negative error code.
2608 */
2609int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2610{
2611 struct gpio_chip *chip;
2612 unsigned long packed;
2613 int gpio;
2614 int rc;
2615
2616 VALIDATE_DESC(desc);
2617 /*
2618 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2619 * persistence state.
2620 */
2621 if (transitory)
2622 set_bit(FLAG_TRANSITORY, &desc->flags);
2623 else
2624 clear_bit(FLAG_TRANSITORY, &desc->flags);
2625
2626 /* If the driver supports it, set the persistence state now */
2627 chip = desc->gdev->chip;
2628 if (!chip->set_config)
2629 return 0;
2630
2631 packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
2632 !transitory);
2633 gpio = gpio_chip_hwgpio(desc);
2634 rc = chip->set_config(chip, gpio, packed);
2635 if (rc == -ENOTSUPP) {
2636 dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
2637 gpio);
2638 return 0;
2639 }
2640
2641 return rc;
2642}
2643EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2644
2645/**
2646 * gpiod_is_active_low - test whether a GPIO is active-low or not
2647 * @desc: the gpio descriptor to test
2648 *
2649 * Returns 1 if the GPIO is active-low, 0 otherwise.
2650 */
2651int gpiod_is_active_low(const struct gpio_desc *desc)
2652{
2653 VALIDATE_DESC(desc);
2654 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2655}
2656EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2657
2658/* I/O calls are only valid after configuration completed; the relevant
2659 * "is this a valid GPIO" error checks should already have been done.
2660 *
2661 * "Get" operations are often inlinable as reading a pin value register,
2662 * and masking the relevant bit in that register.
2663 *
2664 * When "set" operations are inlinable, they involve writing that mask to
2665 * one register to set a low value, or a different register to set it high.
2666 * Otherwise locking is needed, so there may be little value to inlining.
2667 *
2668 *------------------------------------------------------------------------
2669 *
2670 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2671 * have requested the GPIO. That can include implicit requesting by
2672 * a direction setting call. Marking a gpio as requested locks its chip
2673 * in memory, guaranteeing that these table lookups need no more locking
2674 * and that gpiochip_remove() will fail.
2675 *
2676 * REVISIT when debugging, consider adding some instrumentation to ensure
2677 * that the GPIO was actually requested.
2678 */
2679
2680static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2681{
2682 struct gpio_chip *chip;
2683 int offset;
2684 int value;
2685
2686 chip = desc->gdev->chip;
2687 offset = gpio_chip_hwgpio(desc);
2688 value = chip->get ? chip->get(chip, offset) : -EIO;
2689 value = value < 0 ? value : !!value;
2690 trace_gpio_value(desc_to_gpio(desc), 1, value);
2691 return value;
2692}
2693
2694static int gpio_chip_get_multiple(struct gpio_chip *chip,
2695 unsigned long *mask, unsigned long *bits)
2696{
2697 if (chip->get_multiple) {
2698 return chip->get_multiple(chip, mask, bits);
2699 } else if (chip->get) {
2700 int i, value;
2701
2702 for_each_set_bit(i, mask, chip->ngpio) {
2703 value = chip->get(chip, i);
2704 if (value < 0)
2705 return value;
2706 __assign_bit(i, bits, value);
2707 }
2708 return 0;
2709 }
2710 return -EIO;
2711}
2712
2713int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2714 unsigned int array_size,
2715 struct gpio_desc **desc_array,
2716 int *value_array)
2717{
2718 int i = 0;
2719
2720 while (i < array_size) {
2721 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2722 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
2723 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
2724 int first, j, ret;
2725
2726 if (!can_sleep)
2727 WARN_ON(chip->can_sleep);
2728
2729 /* collect all inputs belonging to the same chip */
2730 first = i;
2731 memset(mask, 0, sizeof(mask));
2732 do {
2733 const struct gpio_desc *desc = desc_array[i];
2734 int hwgpio = gpio_chip_hwgpio(desc);
2735
2736 __set_bit(hwgpio, mask);
2737 i++;
2738 } while ((i < array_size) &&
2739 (desc_array[i]->gdev->chip == chip));
2740
2741 ret = gpio_chip_get_multiple(chip, mask, bits);
2742 if (ret)
2743 return ret;
2744
2745 for (j = first; j < i; j++) {
2746 const struct gpio_desc *desc = desc_array[j];
2747 int hwgpio = gpio_chip_hwgpio(desc);
2748 int value = test_bit(hwgpio, bits);
2749
2750 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2751 value = !value;
2752 value_array[j] = value;
2753 trace_gpio_value(desc_to_gpio(desc), 1, value);
2754 }
2755 }
2756 return 0;
2757}
2758
2759/**
2760 * gpiod_get_raw_value() - return a gpio's raw value
2761 * @desc: gpio whose value will be returned
2762 *
2763 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2764 * its ACTIVE_LOW status, or negative errno on failure.
2765 *
2766 * This function should be called from contexts where we cannot sleep, and will
2767 * complain if the GPIO chip functions potentially sleep.
2768 */
2769int gpiod_get_raw_value(const struct gpio_desc *desc)
2770{
2771 VALIDATE_DESC(desc);
2772 /* Should be using gpio_get_value_cansleep() */
2773 WARN_ON(desc->gdev->chip->can_sleep);
2774 return gpiod_get_raw_value_commit(desc);
2775}
2776EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2777
2778/**
2779 * gpiod_get_value() - return a gpio's value
2780 * @desc: gpio whose value will be returned
2781 *
2782 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2783 * account, or negative errno on failure.
2784 *
2785 * This function should be called from contexts where we cannot sleep, and will
2786 * complain if the GPIO chip functions potentially sleep.
2787 */
2788int gpiod_get_value(const struct gpio_desc *desc)
2789{
2790 int value;
2791
2792 VALIDATE_DESC(desc);
2793 /* Should be using gpio_get_value_cansleep() */
2794 WARN_ON(desc->gdev->chip->can_sleep);
2795
2796 value = gpiod_get_raw_value_commit(desc);
2797 if (value < 0)
2798 return value;
2799
2800 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2801 value = !value;
2802
2803 return value;
2804}
2805EXPORT_SYMBOL_GPL(gpiod_get_value);
2806
2807/**
2808 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
2809 * @array_size: number of elements in the descriptor / value arrays
2810 * @desc_array: array of GPIO descriptors whose values will be read
2811 * @value_array: array to store the read values
2812 *
2813 * Read the raw values of the GPIOs, i.e. the values of the physical lines
2814 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
2815 * else an error code.
2816 *
2817 * This function should be called from contexts where we cannot sleep,
2818 * and it will complain if the GPIO chip functions potentially sleep.
2819 */
2820int gpiod_get_raw_array_value(unsigned int array_size,
2821 struct gpio_desc **desc_array, int *value_array)
2822{
2823 if (!desc_array)
2824 return -EINVAL;
2825 return gpiod_get_array_value_complex(true, false, array_size,
2826 desc_array, value_array);
2827}
2828EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
2829
2830/**
2831 * gpiod_get_array_value() - read values from an array of GPIOs
2832 * @array_size: number of elements in the descriptor / value arrays
2833 * @desc_array: array of GPIO descriptors whose values will be read
2834 * @value_array: array to store the read values
2835 *
2836 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2837 * into account. Return 0 in case of success, else an error code.
2838 *
2839 * This function should be called from contexts where we cannot sleep,
2840 * and it will complain if the GPIO chip functions potentially sleep.
2841 */
2842int gpiod_get_array_value(unsigned int array_size,
2843 struct gpio_desc **desc_array, int *value_array)
2844{
2845 if (!desc_array)
2846 return -EINVAL;
2847 return gpiod_get_array_value_complex(false, false, array_size,
2848 desc_array, value_array);
2849}
2850EXPORT_SYMBOL_GPL(gpiod_get_array_value);
2851
2852/*
2853 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
2854 * @desc: gpio descriptor whose state need to be set.
2855 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2856 */
2857static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
2858{
2859 int err = 0;
2860 struct gpio_chip *chip = desc->gdev->chip;
2861 int offset = gpio_chip_hwgpio(desc);
2862
2863 if (value) {
2864 err = chip->direction_input(chip, offset);
2865 if (!err)
2866 clear_bit(FLAG_IS_OUT, &desc->flags);
2867 } else {
2868 err = chip->direction_output(chip, offset, 0);
2869 if (!err)
2870 set_bit(FLAG_IS_OUT, &desc->flags);
2871 }
2872 trace_gpio_direction(desc_to_gpio(desc), value, err);
2873 if (err < 0)
2874 gpiod_err(desc,
2875 "%s: Error in set_value for open drain err %d\n",
2876 __func__, err);
2877}
2878
2879/*
2880 * _gpio_set_open_source_value() - Set the open source gpio's value.
2881 * @desc: gpio descriptor whose state need to be set.
2882 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2883 */
2884static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
2885{
2886 int err = 0;
2887 struct gpio_chip *chip = desc->gdev->chip;
2888 int offset = gpio_chip_hwgpio(desc);
2889
2890 if (value) {
2891 err = chip->direction_output(chip, offset, 1);
2892 if (!err)
2893 set_bit(FLAG_IS_OUT, &desc->flags);
2894 } else {
2895 err = chip->direction_input(chip, offset);
2896 if (!err)
2897 clear_bit(FLAG_IS_OUT, &desc->flags);
2898 }
2899 trace_gpio_direction(desc_to_gpio(desc), !value, err);
2900 if (err < 0)
2901 gpiod_err(desc,
2902 "%s: Error in set_value for open source err %d\n",
2903 __func__, err);
2904}
2905
2906static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
2907{
2908 struct gpio_chip *chip;
2909
2910 chip = desc->gdev->chip;
2911 trace_gpio_value(desc_to_gpio(desc), 0, value);
2912 chip->set(chip, gpio_chip_hwgpio(desc), value);
2913}
2914
2915/*
2916 * set multiple outputs on the same chip;
2917 * use the chip's set_multiple function if available;
2918 * otherwise set the outputs sequentially;
2919 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2920 * defines which outputs are to be changed
2921 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2922 * defines the values the outputs specified by mask are to be set to
2923 */
2924static void gpio_chip_set_multiple(struct gpio_chip *chip,
2925 unsigned long *mask, unsigned long *bits)
2926{
2927 if (chip->set_multiple) {
2928 chip->set_multiple(chip, mask, bits);
2929 } else {
2930 unsigned int i;
2931
2932 /* set outputs if the corresponding mask bit is set */
2933 for_each_set_bit(i, mask, chip->ngpio)
2934 chip->set(chip, i, test_bit(i, bits));
2935 }
2936}
2937
2938void gpiod_set_array_value_complex(bool raw, bool can_sleep,
2939 unsigned int array_size,
2940 struct gpio_desc **desc_array,
2941 int *value_array)
2942{
2943 int i = 0;
2944
2945 while (i < array_size) {
2946 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2947 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
2948 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
2949 int count = 0;
2950
2951 if (!can_sleep)
2952 WARN_ON(chip->can_sleep);
2953
2954 memset(mask, 0, sizeof(mask));
2955 do {
2956 struct gpio_desc *desc = desc_array[i];
2957 int hwgpio = gpio_chip_hwgpio(desc);
2958 int value = value_array[i];
2959
2960 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2961 value = !value;
2962 trace_gpio_value(desc_to_gpio(desc), 0, value);
2963 /*
2964 * collect all normal outputs belonging to the same chip
2965 * open drain and open source outputs are set individually
2966 */
2967 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
2968 gpio_set_open_drain_value_commit(desc, value);
2969 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
2970 gpio_set_open_source_value_commit(desc, value);
2971 } else {
2972 __set_bit(hwgpio, mask);
2973 if (value)
2974 __set_bit(hwgpio, bits);
2975 else
2976 __clear_bit(hwgpio, bits);
2977 count++;
2978 }
2979 i++;
2980 } while ((i < array_size) &&
2981 (desc_array[i]->gdev->chip == chip));
2982 /* push collected bits to outputs */
2983 if (count != 0)
2984 gpio_chip_set_multiple(chip, mask, bits);
2985 }
2986}
2987
2988/**
2989 * gpiod_set_raw_value() - assign a gpio's raw value
2990 * @desc: gpio whose value will be assigned
2991 * @value: value to assign
2992 *
2993 * Set the raw value of the GPIO, i.e. the value of its physical line without
2994 * regard for its ACTIVE_LOW status.
2995 *
2996 * This function should be called from contexts where we cannot sleep, and will
2997 * complain if the GPIO chip functions potentially sleep.
2998 */
2999void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3000{
3001 VALIDATE_DESC_VOID(desc);
3002 /* Should be using gpiod_set_value_cansleep() */
3003 WARN_ON(desc->gdev->chip->can_sleep);
3004 gpiod_set_raw_value_commit(desc, value);
3005}
3006EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3007
3008/**
3009 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3010 * @desc: the descriptor to set the value on
3011 * @value: value to set
3012 *
3013 * This sets the value of a GPIO line backing a descriptor, applying
3014 * different semantic quirks like active low and open drain/source
3015 * handling.
3016 */
3017static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3018{
3019 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3020 value = !value;
3021 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3022 gpio_set_open_drain_value_commit(desc, value);
3023 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3024 gpio_set_open_source_value_commit(desc, value);
3025 else
3026 gpiod_set_raw_value_commit(desc, value);
3027}
3028
3029/**
3030 * gpiod_set_value() - assign a gpio's value
3031 * @desc: gpio whose value will be assigned
3032 * @value: value to assign
3033 *
3034 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3035 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3036 *
3037 * This function should be called from contexts where we cannot sleep, and will
3038 * complain if the GPIO chip functions potentially sleep.
3039 */
3040void gpiod_set_value(struct gpio_desc *desc, int value)
3041{
3042 VALIDATE_DESC_VOID(desc);
3043 WARN_ON(desc->gdev->chip->can_sleep);
3044 gpiod_set_value_nocheck(desc, value);
3045}
3046EXPORT_SYMBOL_GPL(gpiod_set_value);
3047
3048/**
3049 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3050 * @array_size: number of elements in the descriptor / value arrays
3051 * @desc_array: array of GPIO descriptors whose values will be assigned
3052 * @value_array: array of values to assign
3053 *
3054 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3055 * without regard for their ACTIVE_LOW status.
3056 *
3057 * This function should be called from contexts where we cannot sleep, and will
3058 * complain if the GPIO chip functions potentially sleep.
3059 */
3060void gpiod_set_raw_array_value(unsigned int array_size,
3061 struct gpio_desc **desc_array, int *value_array)
3062{
3063 if (!desc_array)
3064 return;
3065 gpiod_set_array_value_complex(true, false, array_size, desc_array,
3066 value_array);
3067}
3068EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3069
3070/**
3071 * gpiod_set_array_value() - assign values to an array of GPIOs
3072 * @array_size: number of elements in the descriptor / value arrays
3073 * @desc_array: array of GPIO descriptors whose values will be assigned
3074 * @value_array: array of values to assign
3075 *
3076 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3077 * into account.
3078 *
3079 * This function should be called from contexts where we cannot sleep, and will
3080 * complain if the GPIO chip functions potentially sleep.
3081 */
3082void gpiod_set_array_value(unsigned int array_size,
3083 struct gpio_desc **desc_array, int *value_array)
3084{
3085 if (!desc_array)
3086 return;
3087 gpiod_set_array_value_complex(false, false, array_size, desc_array,
3088 value_array);
3089}
3090EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3091
3092/**
3093 * gpiod_cansleep() - report whether gpio value access may sleep
3094 * @desc: gpio to check
3095 *
3096 */
3097int gpiod_cansleep(const struct gpio_desc *desc)
3098{
3099 VALIDATE_DESC(desc);
3100 return desc->gdev->chip->can_sleep;
3101}
3102EXPORT_SYMBOL_GPL(gpiod_cansleep);
3103
3104/**
3105 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3106 * @desc: gpio whose IRQ will be returned (already requested)
3107 *
3108 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3109 * error.
3110 */
3111int gpiod_to_irq(const struct gpio_desc *desc)
3112{
3113 struct gpio_chip *chip;
3114 int offset;
3115
3116 /*
3117 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3118 * requires this function to not return zero on an invalid descriptor
3119 * but rather a negative error number.
3120 */
3121 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3122 return -EINVAL;
3123
3124 chip = desc->gdev->chip;
3125 offset = gpio_chip_hwgpio(desc);
3126 if (chip->to_irq) {
3127 int retirq = chip->to_irq(chip, offset);
3128
3129 /* Zero means NO_IRQ */
3130 if (!retirq)
3131 return -ENXIO;
3132
3133 return retirq;
3134 }
3135 return -ENXIO;
3136}
3137EXPORT_SYMBOL_GPL(gpiod_to_irq);
3138
3139/**
3140 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3141 * @chip: the chip the GPIO to lock belongs to
3142 * @offset: the offset of the GPIO to lock as IRQ
3143 *
3144 * This is used directly by GPIO drivers that want to lock down
3145 * a certain GPIO line to be used for IRQs.
3146 */
3147int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
3148{
3149 struct gpio_desc *desc;
3150
3151 desc = gpiochip_get_desc(chip, offset);
3152 if (IS_ERR(desc))
3153 return PTR_ERR(desc);
3154
3155 /*
3156 * If it's fast: flush the direction setting if something changed
3157 * behind our back
3158 */
3159 if (!chip->can_sleep && chip->get_direction) {
3160 int dir = chip->get_direction(chip, offset);
3161
3162 if (dir)
3163 clear_bit(FLAG_IS_OUT, &desc->flags);
3164 else
3165 set_bit(FLAG_IS_OUT, &desc->flags);
3166 }
3167
3168 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
3169 chip_err(chip,
3170 "%s: tried to flag a GPIO set as output for IRQ\n",
3171 __func__);
3172 return -EIO;
3173 }
3174
3175 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3176
3177 /*
3178 * If the consumer has not set up a label (such as when the
3179 * IRQ is referenced from .to_irq()) we set up a label here
3180 * so it is clear this is used as an interrupt.
3181 */
3182 if (!desc->label)
3183 desc_set_label(desc, "interrupt");
3184
3185 return 0;
3186}
3187EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3188
3189/**
3190 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3191 * @chip: the chip the GPIO to lock belongs to
3192 * @offset: the offset of the GPIO to lock as IRQ
3193 *
3194 * This is used directly by GPIO drivers that want to indicate
3195 * that a certain GPIO is no longer used exclusively for IRQ.
3196 */
3197void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
3198{
3199 struct gpio_desc *desc;
3200
3201 desc = gpiochip_get_desc(chip, offset);
3202 if (IS_ERR(desc))
3203 return;
3204
3205 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3206
3207 /* If we only had this marking, erase it */
3208 if (desc->label && !strcmp(desc->label, "interrupt"))
3209 desc_set_label(desc, NULL);
3210}
3211EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3212
3213bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
3214{
3215 if (offset >= chip->ngpio)
3216 return false;
3217
3218 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
3219}
3220EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3221
3222bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
3223{
3224 if (offset >= chip->ngpio)
3225 return false;
3226
3227 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
3228}
3229EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3230
3231bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
3232{
3233 if (offset >= chip->ngpio)
3234 return false;
3235
3236 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
3237}
3238EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3239
3240bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
3241{
3242 if (offset >= chip->ngpio)
3243 return false;
3244
3245 return !test_bit(FLAG_TRANSITORY, &chip->gpiodev->descs[offset].flags);
3246}
3247EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3248
3249/**
3250 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3251 * @desc: gpio whose value will be returned
3252 *
3253 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3254 * its ACTIVE_LOW status, or negative errno on failure.
3255 *
3256 * This function is to be called from contexts that can sleep.
3257 */
3258int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3259{
3260 might_sleep_if(extra_checks);
3261 VALIDATE_DESC(desc);
3262 return gpiod_get_raw_value_commit(desc);
3263}
3264EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3265
3266/**
3267 * gpiod_get_value_cansleep() - return a gpio's value
3268 * @desc: gpio whose value will be returned
3269 *
3270 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3271 * account, or negative errno on failure.
3272 *
3273 * This function is to be called from contexts that can sleep.
3274 */
3275int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3276{
3277 int value;
3278
3279 might_sleep_if(extra_checks);
3280 VALIDATE_DESC(desc);
3281 value = gpiod_get_raw_value_commit(desc);
3282 if (value < 0)
3283 return value;
3284
3285 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3286 value = !value;
3287
3288 return value;
3289}
3290EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3291
3292/**
3293 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3294 * @array_size: number of elements in the descriptor / value arrays
3295 * @desc_array: array of GPIO descriptors whose values will be read
3296 * @value_array: array to store the read values
3297 *
3298 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3299 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3300 * else an error code.
3301 *
3302 * This function is to be called from contexts that can sleep.
3303 */
3304int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3305 struct gpio_desc **desc_array,
3306 int *value_array)
3307{
3308 might_sleep_if(extra_checks);
3309 if (!desc_array)
3310 return -EINVAL;
3311 return gpiod_get_array_value_complex(true, true, array_size,
3312 desc_array, value_array);
3313}
3314EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3315
3316/**
3317 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3318 * @array_size: number of elements in the descriptor / value arrays
3319 * @desc_array: array of GPIO descriptors whose values will be read
3320 * @value_array: array to store the read values
3321 *
3322 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3323 * into account. Return 0 in case of success, else an error code.
3324 *
3325 * This function is to be called from contexts that can sleep.
3326 */
3327int gpiod_get_array_value_cansleep(unsigned int array_size,
3328 struct gpio_desc **desc_array,
3329 int *value_array)
3330{
3331 might_sleep_if(extra_checks);
3332 if (!desc_array)
3333 return -EINVAL;
3334 return gpiod_get_array_value_complex(false, true, array_size,
3335 desc_array, value_array);
3336}
3337EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3338
3339/**
3340 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3341 * @desc: gpio whose value will be assigned
3342 * @value: value to assign
3343 *
3344 * Set the raw value of the GPIO, i.e. the value of its physical line without
3345 * regard for its ACTIVE_LOW status.
3346 *
3347 * This function is to be called from contexts that can sleep.
3348 */
3349void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3350{
3351 might_sleep_if(extra_checks);
3352 VALIDATE_DESC_VOID(desc);
3353 gpiod_set_raw_value_commit(desc, value);
3354}
3355EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3356
3357/**
3358 * gpiod_set_value_cansleep() - assign a gpio's value
3359 * @desc: gpio whose value will be assigned
3360 * @value: value to assign
3361 *
3362 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3363 * account
3364 *
3365 * This function is to be called from contexts that can sleep.
3366 */
3367void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3368{
3369 might_sleep_if(extra_checks);
3370 VALIDATE_DESC_VOID(desc);
3371 gpiod_set_value_nocheck(desc, value);
3372}
3373EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3374
3375/**
3376 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3377 * @array_size: number of elements in the descriptor / value arrays
3378 * @desc_array: array of GPIO descriptors whose values will be assigned
3379 * @value_array: array of values to assign
3380 *
3381 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3382 * without regard for their ACTIVE_LOW status.
3383 *
3384 * This function is to be called from contexts that can sleep.
3385 */
3386void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3387 struct gpio_desc **desc_array,
3388 int *value_array)
3389{
3390 might_sleep_if(extra_checks);
3391 if (!desc_array)
3392 return;
3393 gpiod_set_array_value_complex(true, true, array_size, desc_array,
3394 value_array);
3395}
3396EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3397
3398/**
3399 * gpiod_add_lookup_tables() - register GPIO device consumers
3400 * @tables: list of tables of consumers to register
3401 * @n: number of tables in the list
3402 */
3403void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3404{
3405 unsigned int i;
3406
3407 mutex_lock(&gpio_lookup_lock);
3408
3409 for (i = 0; i < n; i++)
3410 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3411
3412 mutex_unlock(&gpio_lookup_lock);
3413}
3414
3415/**
3416 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3417 * @array_size: number of elements in the descriptor / value arrays
3418 * @desc_array: array of GPIO descriptors whose values will be assigned
3419 * @value_array: array of values to assign
3420 *
3421 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3422 * into account.
3423 *
3424 * This function is to be called from contexts that can sleep.
3425 */
3426void gpiod_set_array_value_cansleep(unsigned int array_size,
3427 struct gpio_desc **desc_array,
3428 int *value_array)
3429{
3430 might_sleep_if(extra_checks);
3431 if (!desc_array)
3432 return;
3433 gpiod_set_array_value_complex(false, true, array_size, desc_array,
3434 value_array);
3435}
3436EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3437
3438/**
3439 * gpiod_add_lookup_table() - register GPIO device consumers
3440 * @table: table of consumers to register
3441 */
3442void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3443{
3444 mutex_lock(&gpio_lookup_lock);
3445
3446 list_add_tail(&table->list, &gpio_lookup_list);
3447
3448 mutex_unlock(&gpio_lookup_lock);
3449}
3450EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3451
3452/**
3453 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3454 * @table: table of consumers to unregister
3455 */
3456void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3457{
3458 mutex_lock(&gpio_lookup_lock);
3459
3460 list_del(&table->list);
3461
3462 mutex_unlock(&gpio_lookup_lock);
3463}
3464EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3465
3466static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3467{
3468 const char *dev_id = dev ? dev_name(dev) : NULL;
3469 struct gpiod_lookup_table *table;
3470
3471 mutex_lock(&gpio_lookup_lock);
3472
3473 list_for_each_entry(table, &gpio_lookup_list, list) {
3474 if (table->dev_id && dev_id) {
3475 /*
3476 * Valid strings on both ends, must be identical to have
3477 * a match
3478 */
3479 if (!strcmp(table->dev_id, dev_id))
3480 goto found;
3481 } else {
3482 /*
3483 * One of the pointers is NULL, so both must be to have
3484 * a match
3485 */
3486 if (dev_id == table->dev_id)
3487 goto found;
3488 }
3489 }
3490 table = NULL;
3491
3492found:
3493 mutex_unlock(&gpio_lookup_lock);
3494 return table;
3495}
3496
3497static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3498 unsigned int idx,
3499 enum gpio_lookup_flags *flags)
3500{
3501 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3502 struct gpiod_lookup_table *table;
3503 struct gpiod_lookup *p;
3504
3505 table = gpiod_find_lookup_table(dev);
3506 if (!table)
3507 return desc;
3508
3509 for (p = &table->table[0]; p->chip_label; p++) {
3510 struct gpio_chip *chip;
3511
3512 /* idx must always match exactly */
3513 if (p->idx != idx)
3514 continue;
3515
3516 /* If the lookup entry has a con_id, require exact match */
3517 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3518 continue;
3519
3520 chip = find_chip_by_name(p->chip_label);
3521
3522 if (!chip) {
3523 dev_err(dev, "cannot find GPIO chip %s\n",
3524 p->chip_label);
3525 return ERR_PTR(-ENODEV);
3526 }
3527
3528 if (chip->ngpio <= p->chip_hwnum) {
3529 dev_err(dev,
3530 "requested GPIO %d is out of range [0..%d] for chip %s\n",
3531 idx, chip->ngpio, chip->label);
3532 return ERR_PTR(-EINVAL);
3533 }
3534
3535 desc = gpiochip_get_desc(chip, p->chip_hwnum);
3536 *flags = p->flags;
3537
3538 return desc;
3539 }
3540
3541 return desc;
3542}
3543
3544static int dt_gpio_count(struct device *dev, const char *con_id)
3545{
3546 int ret;
3547 char propname[32];
3548 unsigned int i;
3549
3550 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3551 if (con_id)
3552 snprintf(propname, sizeof(propname), "%s-%s",
3553 con_id, gpio_suffixes[i]);
3554 else
3555 snprintf(propname, sizeof(propname), "%s",
3556 gpio_suffixes[i]);
3557
3558 ret = of_gpio_named_count(dev->of_node, propname);
3559 if (ret > 0)
3560 break;
3561 }
3562 return ret ? ret : -ENOENT;
3563}
3564
3565static int platform_gpio_count(struct device *dev, const char *con_id)
3566{
3567 struct gpiod_lookup_table *table;
3568 struct gpiod_lookup *p;
3569 unsigned int count = 0;
3570
3571 table = gpiod_find_lookup_table(dev);
3572 if (!table)
3573 return -ENOENT;
3574
3575 for (p = &table->table[0]; p->chip_label; p++) {
3576 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3577 (!con_id && !p->con_id))
3578 count++;
3579 }
3580 if (!count)
3581 return -ENOENT;
3582
3583 return count;
3584}
3585
3586/**
3587 * gpiod_count - return the number of GPIOs associated with a device / function
3588 * or -ENOENT if no GPIO has been assigned to the requested function
3589 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3590 * @con_id: function within the GPIO consumer
3591 */
3592int gpiod_count(struct device *dev, const char *con_id)
3593{
3594 int count = -ENOENT;
3595
3596 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
3597 count = dt_gpio_count(dev, con_id);
3598 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
3599 count = acpi_gpio_count(dev, con_id);
3600
3601 if (count < 0)
3602 count = platform_gpio_count(dev, con_id);
3603
3604 return count;
3605}
3606EXPORT_SYMBOL_GPL(gpiod_count);
3607
3608/**
3609 * gpiod_get - obtain a GPIO for a given GPIO function
3610 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3611 * @con_id: function within the GPIO consumer
3612 * @flags: optional GPIO initialization flags
3613 *
3614 * Return the GPIO descriptor corresponding to the function con_id of device
3615 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3616 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3617 */
3618struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3619 enum gpiod_flags flags)
3620{
3621 return gpiod_get_index(dev, con_id, 0, flags);
3622}
3623EXPORT_SYMBOL_GPL(gpiod_get);
3624
3625/**
3626 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3627 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3628 * @con_id: function within the GPIO consumer
3629 * @flags: optional GPIO initialization flags
3630 *
3631 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3632 * the requested function it will return NULL. This is convenient for drivers
3633 * that need to handle optional GPIOs.
3634 */
3635struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3636 const char *con_id,
3637 enum gpiod_flags flags)
3638{
3639 return gpiod_get_index_optional(dev, con_id, 0, flags);
3640}
3641EXPORT_SYMBOL_GPL(gpiod_get_optional);
3642
3643
3644/**
3645 * gpiod_configure_flags - helper function to configure a given GPIO
3646 * @desc: gpio whose value will be assigned
3647 * @con_id: function within the GPIO consumer
3648 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3649 * of_get_gpio_hog()
3650 * @dflags: gpiod_flags - optional GPIO initialization flags
3651 *
3652 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3653 * requested function and/or index, or another IS_ERR() code if an error
3654 * occurred while trying to acquire the GPIO.
3655 */
3656int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3657 unsigned long lflags, enum gpiod_flags dflags)
3658{
3659 int status;
3660
3661 if (lflags & GPIO_ACTIVE_LOW)
3662 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3663
3664 if (lflags & GPIO_OPEN_DRAIN)
3665 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3666 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
3667 /*
3668 * This enforces open drain mode from the consumer side.
3669 * This is necessary for some busses like I2C, but the lookup
3670 * should *REALLY* have specified them as open drain in the
3671 * first place, so print a little warning here.
3672 */
3673 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3674 gpiod_warn(desc,
3675 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
3676 }
3677
3678 if (lflags & GPIO_OPEN_SOURCE)
3679 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3680
3681 status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
3682 if (status < 0)
3683 return status;
3684
3685 /* No particular flag request, return here... */
3686 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3687 pr_debug("no flags found for %s\n", con_id);
3688 return 0;
3689 }
3690
3691 /* Process flags */
3692 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3693 status = gpiod_direction_output(desc,
3694 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3695 else
3696 status = gpiod_direction_input(desc);
3697
3698 return status;
3699}
3700
3701/**
3702 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3703 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3704 * @con_id: function within the GPIO consumer
3705 * @idx: index of the GPIO to obtain in the consumer
3706 * @flags: optional GPIO initialization flags
3707 *
3708 * This variant of gpiod_get() allows to access GPIOs other than the first
3709 * defined one for functions that define several GPIOs.
3710 *
3711 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3712 * requested function and/or index, or another IS_ERR() code if an error
3713 * occurred while trying to acquire the GPIO.
3714 */
3715struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3716 const char *con_id,
3717 unsigned int idx,
3718 enum gpiod_flags flags)
3719{
3720 struct gpio_desc *desc = NULL;
3721 int status;
3722 enum gpio_lookup_flags lookupflags = 0;
3723 /* Maybe we have a device name, maybe not */
3724 const char *devname = dev ? dev_name(dev) : "?";
3725
3726 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3727
3728 if (dev) {
3729 /* Using device tree? */
3730 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
3731 dev_dbg(dev, "using device tree for GPIO lookup\n");
3732 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3733 } else if (ACPI_COMPANION(dev)) {
3734 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3735 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
3736 }
3737 }
3738
3739 /*
3740 * Either we are not using DT or ACPI, or their lookup did not return
3741 * a result. In that case, use platform lookup as a fallback.
3742 */
3743 if (!desc || desc == ERR_PTR(-ENOENT)) {
3744 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3745 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3746 }
3747
3748 if (IS_ERR(desc)) {
3749 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
3750 return desc;
3751 }
3752
3753 /*
3754 * If a connection label was passed use that, else attempt to use
3755 * the device name as label
3756 */
3757 status = gpiod_request(desc, con_id ? con_id : devname);
3758 if (status < 0)
3759 return ERR_PTR(status);
3760
3761 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3762 if (status < 0) {
3763 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3764 gpiod_put(desc);
3765 return ERR_PTR(status);
3766 }
3767
3768 return desc;
3769}
3770EXPORT_SYMBOL_GPL(gpiod_get_index);
3771
3772/**
3773 * gpiod_get_from_of_node() - obtain a GPIO from an OF node
3774 * @node: handle of the OF node
3775 * @propname: name of the DT property representing the GPIO
3776 * @index: index of the GPIO to obtain for the consumer
3777 * @dflags: GPIO initialization flags
3778 * @label: label to attach to the requested GPIO
3779 *
3780 * Returns:
3781 * On successful request the GPIO pin is configured in accordance with
3782 * provided @dflags. If the node does not have the requested GPIO
3783 * property, NULL is returned.
3784 *
3785 * In case of error an ERR_PTR() is returned.
3786 */
3787struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
3788 const char *propname, int index,
3789 enum gpiod_flags dflags,
3790 const char *label)
3791{
3792 struct gpio_desc *desc;
3793 unsigned long lflags = 0;
3794 enum of_gpio_flags flags;
3795 bool active_low = false;
3796 bool single_ended = false;
3797 bool open_drain = false;
3798 bool transitory = false;
3799 int ret;
3800
3801 desc = of_get_named_gpiod_flags(node, propname,
3802 index, &flags);
3803
3804 if (!desc || IS_ERR(desc)) {
3805 /* If it is not there, just return NULL */
3806 if (PTR_ERR(desc) == -ENOENT)
3807 return NULL;
3808 return desc;
3809 }
3810
3811 active_low = flags & OF_GPIO_ACTIVE_LOW;
3812 single_ended = flags & OF_GPIO_SINGLE_ENDED;
3813 open_drain = flags & OF_GPIO_OPEN_DRAIN;
3814 transitory = flags & OF_GPIO_TRANSITORY;
3815
3816 ret = gpiod_request(desc, label);
3817 if (ret)
3818 return ERR_PTR(ret);
3819
3820 if (active_low)
3821 lflags |= GPIO_ACTIVE_LOW;
3822
3823 if (single_ended) {
3824 if (open_drain)
3825 lflags |= GPIO_OPEN_DRAIN;
3826 else
3827 lflags |= GPIO_OPEN_SOURCE;
3828 }
3829
3830 if (transitory)
3831 lflags |= GPIO_TRANSITORY;
3832
3833 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
3834 if (ret < 0) {
3835 gpiod_put(desc);
3836 return ERR_PTR(ret);
3837 }
3838
3839 return desc;
3840}
3841EXPORT_SYMBOL(gpiod_get_from_of_node);
3842
3843/**
3844 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3845 * @fwnode: handle of the firmware node
3846 * @propname: name of the firmware property representing the GPIO
3847 * @index: index of the GPIO to obtain for the consumer
3848 * @dflags: GPIO initialization flags
3849 * @label: label to attach to the requested GPIO
3850 *
3851 * This function can be used for drivers that get their configuration
3852 * from opaque firmware.
3853 *
3854 * The function properly finds the corresponding GPIO using whatever is the
3855 * underlying firmware interface and then makes sure that the GPIO
3856 * descriptor is requested before it is returned to the caller.
3857 *
3858 * Returns:
3859 * On successful request the GPIO pin is configured in accordance with
3860 * provided @dflags.
3861 *
3862 * In case of error an ERR_PTR() is returned.
3863 */
3864struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
3865 const char *propname, int index,
3866 enum gpiod_flags dflags,
3867 const char *label)
3868{
3869 struct gpio_desc *desc = ERR_PTR(-ENODEV);
3870 unsigned long lflags = 0;
3871 int ret;
3872
3873 if (!fwnode)
3874 return ERR_PTR(-EINVAL);
3875
3876 if (is_of_node(fwnode)) {
3877 desc = gpiod_get_from_of_node(to_of_node(fwnode),
3878 propname, index,
3879 dflags,
3880 label);
3881 return desc;
3882 } else if (is_acpi_node(fwnode)) {
3883 struct acpi_gpio_info info;
3884
3885 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
3886 if (IS_ERR(desc))
3887 return desc;
3888
3889 acpi_gpio_update_gpiod_flags(&dflags, &info);
3890
3891 if (info.polarity == GPIO_ACTIVE_LOW)
3892 lflags |= GPIO_ACTIVE_LOW;
3893 }
3894
3895 /* Currently only ACPI takes this path */
3896 ret = gpiod_request(desc, label);
3897 if (ret)
3898 return ERR_PTR(ret);
3899
3900 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
3901 if (ret < 0) {
3902 gpiod_put(desc);
3903 return ERR_PTR(ret);
3904 }
3905
3906 return desc;
3907}
3908EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
3909
3910/**
3911 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
3912 * function
3913 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3914 * @con_id: function within the GPIO consumer
3915 * @index: index of the GPIO to obtain in the consumer
3916 * @flags: optional GPIO initialization flags
3917 *
3918 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
3919 * specified index was assigned to the requested function it will return NULL.
3920 * This is convenient for drivers that need to handle optional GPIOs.
3921 */
3922struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
3923 const char *con_id,
3924 unsigned int index,
3925 enum gpiod_flags flags)
3926{
3927 struct gpio_desc *desc;
3928
3929 desc = gpiod_get_index(dev, con_id, index, flags);
3930 if (IS_ERR(desc)) {
3931 if (PTR_ERR(desc) == -ENOENT)
3932 return NULL;
3933 }
3934
3935 return desc;
3936}
3937EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
3938
3939/**
3940 * gpiod_hog - Hog the specified GPIO desc given the provided flags
3941 * @desc: gpio whose value will be assigned
3942 * @name: gpio line name
3943 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3944 * of_get_gpio_hog()
3945 * @dflags: gpiod_flags - optional GPIO initialization flags
3946 */
3947int gpiod_hog(struct gpio_desc *desc, const char *name,
3948 unsigned long lflags, enum gpiod_flags dflags)
3949{
3950 struct gpio_chip *chip;
3951 struct gpio_desc *local_desc;
3952 int hwnum;
3953 int status;
3954
3955 chip = gpiod_to_chip(desc);
3956 hwnum = gpio_chip_hwgpio(desc);
3957
3958 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
3959 if (IS_ERR(local_desc)) {
3960 status = PTR_ERR(local_desc);
3961 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
3962 name, chip->label, hwnum, status);
3963 return status;
3964 }
3965
3966 status = gpiod_configure_flags(desc, name, lflags, dflags);
3967 if (status < 0) {
3968 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
3969 name, chip->label, hwnum, status);
3970 gpiochip_free_own_desc(desc);
3971 return status;
3972 }
3973
3974 /* Mark GPIO as hogged so it can be identified and removed later */
3975 set_bit(FLAG_IS_HOGGED, &desc->flags);
3976
3977 pr_info("GPIO line %d (%s) hogged as %s%s\n",
3978 desc_to_gpio(desc), name,
3979 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
3980 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
3981 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
3982
3983 return 0;
3984}
3985
3986/**
3987 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
3988 * @chip: gpio chip to act on
3989 *
3990 * This is only used by of_gpiochip_remove to free hogged gpios
3991 */
3992static void gpiochip_free_hogs(struct gpio_chip *chip)
3993{
3994 int id;
3995
3996 for (id = 0; id < chip->ngpio; id++) {
3997 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
3998 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
3999 }
4000}
4001
4002/**
4003 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4004 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4005 * @con_id: function within the GPIO consumer
4006 * @flags: optional GPIO initialization flags
4007 *
4008 * This function acquires all the GPIOs defined under a given function.
4009 *
4010 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4011 * no GPIO has been assigned to the requested function, or another IS_ERR()
4012 * code if an error occurred while trying to acquire the GPIOs.
4013 */
4014struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4015 const char *con_id,
4016 enum gpiod_flags flags)
4017{
4018 struct gpio_desc *desc;
4019 struct gpio_descs *descs;
4020 int count;
4021
4022 count = gpiod_count(dev, con_id);
4023 if (count < 0)
4024 return ERR_PTR(count);
4025
4026 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
4027 GFP_KERNEL);
4028 if (!descs)
4029 return ERR_PTR(-ENOMEM);
4030
4031 for (descs->ndescs = 0; descs->ndescs < count; ) {
4032 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4033 if (IS_ERR(desc)) {
4034 gpiod_put_array(descs);
4035 return ERR_CAST(desc);
4036 }
4037 descs->desc[descs->ndescs] = desc;
4038 descs->ndescs++;
4039 }
4040 return descs;
4041}
4042EXPORT_SYMBOL_GPL(gpiod_get_array);
4043
4044/**
4045 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4046 * function
4047 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4048 * @con_id: function within the GPIO consumer
4049 * @flags: optional GPIO initialization flags
4050 *
4051 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4052 * assigned to the requested function it will return NULL.
4053 */
4054struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4055 const char *con_id,
4056 enum gpiod_flags flags)
4057{
4058 struct gpio_descs *descs;
4059
4060 descs = gpiod_get_array(dev, con_id, flags);
4061 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
4062 return NULL;
4063
4064 return descs;
4065}
4066EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4067
4068/**
4069 * gpiod_put - dispose of a GPIO descriptor
4070 * @desc: GPIO descriptor to dispose of
4071 *
4072 * No descriptor can be used after gpiod_put() has been called on it.
4073 */
4074void gpiod_put(struct gpio_desc *desc)
4075{
4076 gpiod_free(desc);
4077}
4078EXPORT_SYMBOL_GPL(gpiod_put);
4079
4080/**
4081 * gpiod_put_array - dispose of multiple GPIO descriptors
4082 * @descs: struct gpio_descs containing an array of descriptors
4083 */
4084void gpiod_put_array(struct gpio_descs *descs)
4085{
4086 unsigned int i;
4087
4088 for (i = 0; i < descs->ndescs; i++)
4089 gpiod_put(descs->desc[i]);
4090
4091 kfree(descs);
4092}
4093EXPORT_SYMBOL_GPL(gpiod_put_array);
4094
4095static int __init gpiolib_dev_init(void)
4096{
4097 int ret;
4098
4099 /* Register GPIO sysfs bus */
4100 ret = bus_register(&gpio_bus_type);
4101 if (ret < 0) {
4102 pr_err("gpiolib: could not register GPIO bus type\n");
4103 return ret;
4104 }
4105
4106 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
4107 if (ret < 0) {
4108 pr_err("gpiolib: failed to allocate char dev region\n");
4109 bus_unregister(&gpio_bus_type);
4110 } else {
4111 gpiolib_initialized = true;
4112 gpiochip_setup_devs();
4113 }
4114 return ret;
4115}
4116core_initcall(gpiolib_dev_init);
4117
4118#ifdef CONFIG_DEBUG_FS
4119
4120static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4121{
4122 unsigned i;
4123 struct gpio_chip *chip = gdev->chip;
4124 unsigned gpio = gdev->base;
4125 struct gpio_desc *gdesc = &gdev->descs[0];
4126 int is_out;
4127 int is_irq;
4128
4129 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4130 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4131 if (gdesc->name) {
4132 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4133 gpio, gdesc->name);
4134 }
4135 continue;
4136 }
4137
4138 gpiod_get_direction(gdesc);
4139 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4140 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4141 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
4142 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4143 is_out ? "out" : "in ",
4144 chip->get
4145 ? (chip->get(chip, i) ? "hi" : "lo")
4146 : "? ",
4147 is_irq ? "IRQ" : " ");
4148 seq_printf(s, "\n");
4149 }
4150}
4151
4152static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4153{
4154 unsigned long flags;
4155 struct gpio_device *gdev = NULL;
4156 loff_t index = *pos;
4157
4158 s->private = "";
4159
4160 spin_lock_irqsave(&gpio_lock, flags);
4161 list_for_each_entry(gdev, &gpio_devices, list)
4162 if (index-- == 0) {
4163 spin_unlock_irqrestore(&gpio_lock, flags);
4164 return gdev;
4165 }
4166 spin_unlock_irqrestore(&gpio_lock, flags);
4167
4168 return NULL;
4169}
4170
4171static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4172{
4173 unsigned long flags;
4174 struct gpio_device *gdev = v;
4175 void *ret = NULL;
4176
4177 spin_lock_irqsave(&gpio_lock, flags);
4178 if (list_is_last(&gdev->list, &gpio_devices))
4179 ret = NULL;
4180 else
4181 ret = list_entry(gdev->list.next, struct gpio_device, list);
4182 spin_unlock_irqrestore(&gpio_lock, flags);
4183
4184 s->private = "\n";
4185 ++*pos;
4186
4187 return ret;
4188}
4189
4190static void gpiolib_seq_stop(struct seq_file *s, void *v)
4191{
4192}
4193
4194static int gpiolib_seq_show(struct seq_file *s, void *v)
4195{
4196 struct gpio_device *gdev = v;
4197 struct gpio_chip *chip = gdev->chip;
4198 struct device *parent;
4199
4200 if (!chip) {
4201 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4202 dev_name(&gdev->dev));
4203 return 0;
4204 }
4205
4206 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4207 dev_name(&gdev->dev),
4208 gdev->base, gdev->base + gdev->ngpio - 1);
4209 parent = chip->parent;
4210 if (parent)
4211 seq_printf(s, ", parent: %s/%s",
4212 parent->bus ? parent->bus->name : "no-bus",
4213 dev_name(parent));
4214 if (chip->label)
4215 seq_printf(s, ", %s", chip->label);
4216 if (chip->can_sleep)
4217 seq_printf(s, ", can sleep");
4218 seq_printf(s, ":\n");
4219
4220 if (chip->dbg_show)
4221 chip->dbg_show(s, chip);
4222 else
4223 gpiolib_dbg_show(s, gdev);
4224
4225 return 0;
4226}
4227
4228static const struct seq_operations gpiolib_seq_ops = {
4229 .start = gpiolib_seq_start,
4230 .next = gpiolib_seq_next,
4231 .stop = gpiolib_seq_stop,
4232 .show = gpiolib_seq_show,
4233};
4234
4235static int gpiolib_open(struct inode *inode, struct file *file)
4236{
4237 return seq_open(file, &gpiolib_seq_ops);
4238}
4239
4240static const struct file_operations gpiolib_operations = {
4241 .owner = THIS_MODULE,
4242 .open = gpiolib_open,
4243 .read = seq_read,
4244 .llseek = seq_lseek,
4245 .release = seq_release,
4246};
4247
4248static int __init gpiolib_debugfs_init(void)
4249{
4250 /* /sys/kernel/debug/gpio */
4251 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
4252 NULL, NULL, &gpiolib_operations);
4253 return 0;
4254}
4255subsys_initcall(gpiolib_debugfs_init);
4256
4257#endif /* DEBUG_FS */