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