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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * GPIO testing driver based on configfs.
4 *
5 * Copyright (C) 2021 Bartosz Golaszewski <brgl@bgdev.pl>
6 */
7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/array_size.h>
11#include <linux/bitmap.h>
12#include <linux/cleanup.h>
13#include <linux/completion.h>
14#include <linux/configfs.h>
15#include <linux/device.h>
16#include <linux/err.h>
17#include <linux/gpio/consumer.h>
18#include <linux/gpio/driver.h>
19#include <linux/gpio/machine.h>
20#include <linux/idr.h>
21#include <linux/interrupt.h>
22#include <linux/irq.h>
23#include <linux/irq_sim.h>
24#include <linux/list.h>
25#include <linux/lockdep.h>
26#include <linux/minmax.h>
27#include <linux/mod_devicetable.h>
28#include <linux/module.h>
29#include <linux/mutex.h>
30#include <linux/notifier.h>
31#include <linux/platform_device.h>
32#include <linux/property.h>
33#include <linux/seq_file.h>
34#include <linux/slab.h>
35#include <linux/string.h>
36#include <linux/string_helpers.h>
37#include <linux/sysfs.h>
38#include <linux/types.h>
39
40#define GPIO_SIM_NGPIO_MAX 1024
41#define GPIO_SIM_PROP_MAX 4 /* Max 3 properties + sentinel. */
42#define GPIO_SIM_NUM_ATTRS 3 /* value, pull and sentinel */
43
44static DEFINE_IDA(gpio_sim_ida);
45
46struct gpio_sim_chip {
47 struct gpio_chip gc;
48 struct device *dev;
49 unsigned long *request_map;
50 unsigned long *direction_map;
51 unsigned long *value_map;
52 unsigned long *pull_map;
53 struct irq_domain *irq_sim;
54 struct mutex lock;
55 const struct attribute_group **attr_groups;
56};
57
58struct gpio_sim_attribute {
59 struct device_attribute dev_attr;
60 unsigned int offset;
61};
62
63static struct gpio_sim_attribute *
64to_gpio_sim_attr(struct device_attribute *dev_attr)
65{
66 return container_of(dev_attr, struct gpio_sim_attribute, dev_attr);
67}
68
69static int gpio_sim_apply_pull(struct gpio_sim_chip *chip,
70 unsigned int offset, int value)
71{
72 int irq, irq_type, ret;
73
74 guard(mutex)(&chip->lock);
75
76 if (test_bit(offset, chip->request_map) &&
77 test_bit(offset, chip->direction_map)) {
78 if (value == !!test_bit(offset, chip->value_map))
79 goto set_pull;
80
81 /*
82 * This is fine - it just means, nobody is listening
83 * for interrupts on this line, otherwise
84 * irq_create_mapping() would have been called from
85 * the to_irq() callback.
86 */
87 irq = irq_find_mapping(chip->irq_sim, offset);
88 if (!irq)
89 goto set_value;
90
91 irq_type = irq_get_trigger_type(irq);
92
93 if ((value && (irq_type & IRQ_TYPE_EDGE_RISING)) ||
94 (!value && (irq_type & IRQ_TYPE_EDGE_FALLING))) {
95 ret = irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING,
96 true);
97 if (ret)
98 goto set_pull;
99 }
100 }
101
102set_value:
103 /* Change the value unless we're actively driving the line. */
104 if (!test_bit(offset, chip->request_map) ||
105 test_bit(offset, chip->direction_map))
106 __assign_bit(offset, chip->value_map, value);
107
108set_pull:
109 __assign_bit(offset, chip->pull_map, value);
110 return 0;
111}
112
113static int gpio_sim_get(struct gpio_chip *gc, unsigned int offset)
114{
115 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
116
117 guard(mutex)(&chip->lock);
118
119 return !!test_bit(offset, chip->value_map);
120}
121
122static void gpio_sim_set(struct gpio_chip *gc, unsigned int offset, int value)
123{
124 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
125
126 scoped_guard(mutex, &chip->lock)
127 __assign_bit(offset, chip->value_map, value);
128}
129
130static int gpio_sim_get_multiple(struct gpio_chip *gc,
131 unsigned long *mask, unsigned long *bits)
132{
133 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
134
135 scoped_guard(mutex, &chip->lock)
136 bitmap_replace(bits, bits, chip->value_map, mask, gc->ngpio);
137
138 return 0;
139}
140
141static void gpio_sim_set_multiple(struct gpio_chip *gc,
142 unsigned long *mask, unsigned long *bits)
143{
144 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
145
146 scoped_guard(mutex, &chip->lock)
147 bitmap_replace(chip->value_map, chip->value_map, bits, mask,
148 gc->ngpio);
149}
150
151static int gpio_sim_direction_output(struct gpio_chip *gc,
152 unsigned int offset, int value)
153{
154 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
155
156 scoped_guard(mutex, &chip->lock) {
157 __clear_bit(offset, chip->direction_map);
158 __assign_bit(offset, chip->value_map, value);
159 }
160
161 return 0;
162}
163
164static int gpio_sim_direction_input(struct gpio_chip *gc, unsigned int offset)
165{
166 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
167
168 scoped_guard(mutex, &chip->lock)
169 __set_bit(offset, chip->direction_map);
170
171 return 0;
172}
173
174static int gpio_sim_get_direction(struct gpio_chip *gc, unsigned int offset)
175{
176 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
177 int direction;
178
179 scoped_guard(mutex, &chip->lock)
180 direction = !!test_bit(offset, chip->direction_map);
181
182 return direction ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT;
183}
184
185static int gpio_sim_set_config(struct gpio_chip *gc, unsigned int offset,
186 unsigned long config)
187{
188 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
189
190 switch (pinconf_to_config_param(config)) {
191 case PIN_CONFIG_BIAS_PULL_UP:
192 return gpio_sim_apply_pull(chip, offset, 1);
193 case PIN_CONFIG_BIAS_PULL_DOWN:
194 return gpio_sim_apply_pull(chip, offset, 0);
195 default:
196 break;
197 }
198
199 return -ENOTSUPP;
200}
201
202static int gpio_sim_to_irq(struct gpio_chip *gc, unsigned int offset)
203{
204 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
205
206 return irq_create_mapping(chip->irq_sim, offset);
207}
208
209static int gpio_sim_request(struct gpio_chip *gc, unsigned int offset)
210{
211 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
212
213 scoped_guard(mutex, &chip->lock)
214 __set_bit(offset, chip->request_map);
215
216 return 0;
217}
218
219static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset)
220{
221 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
222
223 scoped_guard(mutex, &chip->lock) {
224 __assign_bit(offset, chip->value_map,
225 !!test_bit(offset, chip->pull_map));
226 __clear_bit(offset, chip->request_map);
227 }
228}
229
230static int gpio_sim_irq_requested(struct irq_domain *domain,
231 irq_hw_number_t hwirq, void *data)
232{
233 struct gpio_sim_chip *chip = data;
234
235 return gpiochip_lock_as_irq(&chip->gc, hwirq);
236}
237
238static void gpio_sim_irq_released(struct irq_domain *domain,
239 irq_hw_number_t hwirq, void *data)
240{
241 struct gpio_sim_chip *chip = data;
242
243 gpiochip_unlock_as_irq(&chip->gc, hwirq);
244}
245
246static const struct irq_sim_ops gpio_sim_irq_sim_ops = {
247 .irq_sim_irq_requested = gpio_sim_irq_requested,
248 .irq_sim_irq_released = gpio_sim_irq_released,
249};
250
251static void gpio_sim_dbg_show(struct seq_file *seq, struct gpio_chip *gc)
252{
253 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
254 const char *label;
255 int i;
256
257 guard(mutex)(&chip->lock);
258
259 for_each_hwgpio(gc, i, label)
260 seq_printf(seq, " gpio-%-3d (%s) %s,%s\n",
261 gc->base + i,
262 label ?: "<unused>",
263 test_bit(i, chip->direction_map) ? "input" :
264 test_bit(i, chip->value_map) ? "output-high" :
265 "output-low",
266 test_bit(i, chip->pull_map) ? "pull-up" :
267 "pull-down");
268}
269
270static ssize_t gpio_sim_sysfs_val_show(struct device *dev,
271 struct device_attribute *attr, char *buf)
272{
273 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
274 struct gpio_sim_chip *chip = dev_get_drvdata(dev);
275 int val;
276
277 scoped_guard(mutex, &chip->lock)
278 val = !!test_bit(line_attr->offset, chip->value_map);
279
280 return sysfs_emit(buf, "%d\n", val);
281}
282
283static ssize_t gpio_sim_sysfs_val_store(struct device *dev,
284 struct device_attribute *attr,
285 const char *buf, size_t count)
286{
287 /*
288 * Not assigning this function will result in write() returning -EIO
289 * which is confusing. Return -EPERM explicitly.
290 */
291 return -EPERM;
292}
293
294static const char *const gpio_sim_sysfs_pull_strings[] = {
295 [0] = "pull-down",
296 [1] = "pull-up",
297};
298
299static ssize_t gpio_sim_sysfs_pull_show(struct device *dev,
300 struct device_attribute *attr,
301 char *buf)
302{
303 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
304 struct gpio_sim_chip *chip = dev_get_drvdata(dev);
305 int pull;
306
307 scoped_guard(mutex, &chip->lock)
308 pull = !!test_bit(line_attr->offset, chip->pull_map);
309
310 return sysfs_emit(buf, "%s\n", gpio_sim_sysfs_pull_strings[pull]);
311}
312
313static ssize_t gpio_sim_sysfs_pull_store(struct device *dev,
314 struct device_attribute *attr,
315 const char *buf, size_t len)
316{
317 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
318 struct gpio_sim_chip *chip = dev_get_drvdata(dev);
319 int ret, pull;
320
321 pull = sysfs_match_string(gpio_sim_sysfs_pull_strings, buf);
322 if (pull < 0)
323 return pull;
324
325 ret = gpio_sim_apply_pull(chip, line_attr->offset, pull);
326 if (ret)
327 return ret;
328
329 return len;
330}
331
332static void gpio_sim_put_device(void *data)
333{
334 struct device *dev = data;
335
336 put_device(dev);
337}
338
339static void gpio_sim_dispose_mappings(void *data)
340{
341 struct gpio_sim_chip *chip = data;
342 unsigned int i;
343
344 for (i = 0; i < chip->gc.ngpio; i++)
345 irq_dispose_mapping(irq_find_mapping(chip->irq_sim, i));
346}
347
348static void gpio_sim_sysfs_remove(void *data)
349{
350 struct gpio_sim_chip *chip = data;
351
352 sysfs_remove_groups(&chip->dev->kobj, chip->attr_groups);
353}
354
355static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip)
356{
357 struct device_attribute *val_dev_attr, *pull_dev_attr;
358 struct gpio_sim_attribute *val_attr, *pull_attr;
359 unsigned int num_lines = chip->gc.ngpio;
360 struct device *dev = chip->gc.parent;
361 struct attribute_group *attr_group;
362 struct attribute **attrs;
363 int i, ret;
364
365 chip->attr_groups = devm_kcalloc(dev, sizeof(*chip->attr_groups),
366 num_lines + 1, GFP_KERNEL);
367 if (!chip->attr_groups)
368 return -ENOMEM;
369
370 for (i = 0; i < num_lines; i++) {
371 attr_group = devm_kzalloc(dev, sizeof(*attr_group), GFP_KERNEL);
372 attrs = devm_kcalloc(dev, GPIO_SIM_NUM_ATTRS, sizeof(*attrs),
373 GFP_KERNEL);
374 val_attr = devm_kzalloc(dev, sizeof(*val_attr), GFP_KERNEL);
375 pull_attr = devm_kzalloc(dev, sizeof(*pull_attr), GFP_KERNEL);
376 if (!attr_group || !attrs || !val_attr || !pull_attr)
377 return -ENOMEM;
378
379 attr_group->name = devm_kasprintf(dev, GFP_KERNEL,
380 "sim_gpio%u", i);
381 if (!attr_group->name)
382 return -ENOMEM;
383
384 val_attr->offset = pull_attr->offset = i;
385
386 val_dev_attr = &val_attr->dev_attr;
387 pull_dev_attr = &pull_attr->dev_attr;
388
389 sysfs_attr_init(&val_dev_attr->attr);
390 sysfs_attr_init(&pull_dev_attr->attr);
391
392 val_dev_attr->attr.name = "value";
393 pull_dev_attr->attr.name = "pull";
394
395 val_dev_attr->attr.mode = pull_dev_attr->attr.mode = 0644;
396
397 val_dev_attr->show = gpio_sim_sysfs_val_show;
398 val_dev_attr->store = gpio_sim_sysfs_val_store;
399 pull_dev_attr->show = gpio_sim_sysfs_pull_show;
400 pull_dev_attr->store = gpio_sim_sysfs_pull_store;
401
402 attrs[0] = &val_dev_attr->attr;
403 attrs[1] = &pull_dev_attr->attr;
404
405 attr_group->attrs = attrs;
406 chip->attr_groups[i] = attr_group;
407 }
408
409 ret = sysfs_create_groups(&chip->dev->kobj, chip->attr_groups);
410 if (ret)
411 return ret;
412
413 return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip);
414}
415
416static int gpio_sim_dev_match_fwnode(struct device *dev, void *data)
417{
418 return device_match_fwnode(dev, data);
419}
420
421static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
422{
423 struct gpio_sim_chip *chip;
424 struct gpio_chip *gc;
425 const char *label;
426 u32 num_lines;
427 int ret;
428
429 ret = fwnode_property_read_u32(swnode, "ngpios", &num_lines);
430 if (ret)
431 return ret;
432
433 if (num_lines > GPIO_SIM_NGPIO_MAX)
434 return -ERANGE;
435
436 ret = fwnode_property_read_string(swnode, "gpio-sim,label", &label);
437 if (ret) {
438 label = devm_kasprintf(dev, GFP_KERNEL, "%s:%pfwP",
439 dev_name(dev), swnode);
440 if (!label)
441 return -ENOMEM;
442 }
443
444 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
445 if (!chip)
446 return -ENOMEM;
447
448 chip->request_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL);
449 if (!chip->request_map)
450 return -ENOMEM;
451
452 chip->direction_map = devm_bitmap_alloc(dev, num_lines, GFP_KERNEL);
453 if (!chip->direction_map)
454 return -ENOMEM;
455
456 /* Default to input mode. */
457 bitmap_fill(chip->direction_map, num_lines);
458
459 chip->value_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL);
460 if (!chip->value_map)
461 return -ENOMEM;
462
463 chip->pull_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL);
464 if (!chip->pull_map)
465 return -ENOMEM;
466
467 chip->irq_sim = devm_irq_domain_create_sim_full(dev, swnode, num_lines,
468 &gpio_sim_irq_sim_ops,
469 chip);
470 if (IS_ERR(chip->irq_sim))
471 return PTR_ERR(chip->irq_sim);
472
473 ret = devm_add_action_or_reset(dev, gpio_sim_dispose_mappings, chip);
474 if (ret)
475 return ret;
476
477 ret = devm_mutex_init(dev, &chip->lock);
478 if (ret)
479 return ret;
480
481 gc = &chip->gc;
482 gc->base = -1;
483 gc->ngpio = num_lines;
484 gc->label = label;
485 gc->owner = THIS_MODULE;
486 gc->parent = dev;
487 gc->fwnode = swnode;
488 gc->get = gpio_sim_get;
489 gc->set = gpio_sim_set;
490 gc->get_multiple = gpio_sim_get_multiple;
491 gc->set_multiple = gpio_sim_set_multiple;
492 gc->direction_output = gpio_sim_direction_output;
493 gc->direction_input = gpio_sim_direction_input;
494 gc->get_direction = gpio_sim_get_direction;
495 gc->set_config = gpio_sim_set_config;
496 gc->to_irq = gpio_sim_to_irq;
497 gc->request = gpio_sim_request;
498 gc->free = gpio_sim_free;
499 gc->dbg_show = PTR_IF(IS_ENABLED(CONFIG_DEBUG_FS), gpio_sim_dbg_show);
500 gc->can_sleep = true;
501
502 ret = devm_gpiochip_add_data(dev, gc, chip);
503 if (ret)
504 return ret;
505
506 chip->dev = device_find_child(dev, swnode, gpio_sim_dev_match_fwnode);
507 if (!chip->dev)
508 return -ENODEV;
509
510 ret = devm_add_action_or_reset(dev, gpio_sim_put_device, chip->dev);
511 if (ret)
512 return ret;
513
514 /* Used by sysfs callbacks. */
515 dev_set_drvdata(chip->dev, chip);
516
517 return gpio_sim_setup_sysfs(chip);
518}
519
520static int gpio_sim_probe(struct platform_device *pdev)
521{
522 struct device *dev = &pdev->dev;
523 int ret;
524
525 device_for_each_child_node_scoped(dev, swnode) {
526 ret = gpio_sim_add_bank(swnode, dev);
527 if (ret)
528 return ret;
529 }
530
531 return 0;
532}
533
534static const struct of_device_id gpio_sim_of_match[] = {
535 { .compatible = "gpio-simulator" },
536 { }
537};
538MODULE_DEVICE_TABLE(of, gpio_sim_of_match);
539
540static struct platform_driver gpio_sim_driver = {
541 .driver = {
542 .name = "gpio-sim",
543 .of_match_table = gpio_sim_of_match,
544 },
545 .probe = gpio_sim_probe,
546};
547
548struct gpio_sim_device {
549 struct config_group group;
550
551 /*
552 * If pdev is NULL, the device is 'pending' (waiting for configuration).
553 * Once the pointer is assigned, the device has been created and the
554 * item is 'live'.
555 */
556 struct platform_device *pdev;
557 int id;
558
559 /*
560 * Each configfs filesystem operation is protected with the subsystem
561 * mutex. Each separate attribute is protected with the buffer mutex.
562 * This structure however can be modified by callbacks of different
563 * attributes so we need another lock.
564 *
565 * We use this lock for protecting all data structures owned by this
566 * object too.
567 */
568 struct mutex lock;
569
570 /*
571 * This is used to synchronously wait for the driver's probe to complete
572 * and notify the user-space about any errors.
573 */
574 struct notifier_block bus_notifier;
575 struct completion probe_completion;
576 bool driver_bound;
577
578 struct gpiod_hog *hogs;
579
580 struct list_head bank_list;
581};
582
583/* This is called with dev->lock already taken. */
584static int gpio_sim_bus_notifier_call(struct notifier_block *nb,
585 unsigned long action, void *data)
586{
587 struct gpio_sim_device *simdev = container_of(nb,
588 struct gpio_sim_device,
589 bus_notifier);
590 struct device *dev = data;
591 char devname[32];
592
593 snprintf(devname, sizeof(devname), "gpio-sim.%u", simdev->id);
594
595 if (!device_match_name(dev, devname))
596 return NOTIFY_DONE;
597
598 if (action == BUS_NOTIFY_BOUND_DRIVER)
599 simdev->driver_bound = true;
600 else if (action == BUS_NOTIFY_DRIVER_NOT_BOUND)
601 simdev->driver_bound = false;
602 else
603 return NOTIFY_DONE;
604
605 complete(&simdev->probe_completion);
606
607 return NOTIFY_OK;
608}
609
610static struct gpio_sim_device *to_gpio_sim_device(struct config_item *item)
611{
612 struct config_group *group = to_config_group(item);
613
614 return container_of(group, struct gpio_sim_device, group);
615}
616
617struct gpio_sim_bank {
618 struct config_group group;
619
620 /*
621 * We could have used the ci_parent field of the config_item but
622 * configfs is stupid and calls the item's release callback after
623 * already having cleared the parent pointer even though the parent
624 * is guaranteed to survive the child...
625 *
626 * So we need to store the pointer to the parent struct here. We can
627 * dereference it anywhere we need with no checks and no locking as
628 * it's guaranteed to survive the children and protected by configfs
629 * locks.
630 *
631 * Same for other structures.
632 */
633 struct gpio_sim_device *parent;
634 struct list_head siblings;
635
636 char *label;
637 unsigned int num_lines;
638
639 struct list_head line_list;
640
641 struct fwnode_handle *swnode;
642};
643
644static struct gpio_sim_bank *to_gpio_sim_bank(struct config_item *item)
645{
646 struct config_group *group = to_config_group(item);
647
648 return container_of(group, struct gpio_sim_bank, group);
649}
650
651static bool gpio_sim_bank_has_label(struct gpio_sim_bank *bank)
652{
653 return bank->label && *bank->label;
654}
655
656static struct gpio_sim_device *
657gpio_sim_bank_get_device(struct gpio_sim_bank *bank)
658{
659 return bank->parent;
660}
661
662struct gpio_sim_hog;
663
664struct gpio_sim_line {
665 struct config_group group;
666
667 struct gpio_sim_bank *parent;
668 struct list_head siblings;
669
670 unsigned int offset;
671 char *name;
672
673 /* There can only be one hog per line. */
674 struct gpio_sim_hog *hog;
675};
676
677static struct gpio_sim_line *to_gpio_sim_line(struct config_item *item)
678{
679 struct config_group *group = to_config_group(item);
680
681 return container_of(group, struct gpio_sim_line, group);
682}
683
684static struct gpio_sim_device *
685gpio_sim_line_get_device(struct gpio_sim_line *line)
686{
687 struct gpio_sim_bank *bank = line->parent;
688
689 return gpio_sim_bank_get_device(bank);
690}
691
692struct gpio_sim_hog {
693 struct config_item item;
694 struct gpio_sim_line *parent;
695
696 char *name;
697 int dir;
698};
699
700static struct gpio_sim_hog *to_gpio_sim_hog(struct config_item *item)
701{
702 return container_of(item, struct gpio_sim_hog, item);
703}
704
705static struct gpio_sim_device *gpio_sim_hog_get_device(struct gpio_sim_hog *hog)
706{
707 struct gpio_sim_line *line = hog->parent;
708
709 return gpio_sim_line_get_device(line);
710}
711
712static bool gpio_sim_device_is_live(struct gpio_sim_device *dev)
713{
714 lockdep_assert_held(&dev->lock);
715
716 return !!dev->pdev;
717}
718
719static char *gpio_sim_strdup_trimmed(const char *str, size_t count)
720{
721 char *trimmed;
722
723 trimmed = kstrndup(skip_spaces(str), count, GFP_KERNEL);
724 if (!trimmed)
725 return NULL;
726
727 return strim(trimmed);
728}
729
730static ssize_t gpio_sim_device_config_dev_name_show(struct config_item *item,
731 char *page)
732{
733 struct gpio_sim_device *dev = to_gpio_sim_device(item);
734 struct platform_device *pdev;
735
736 guard(mutex)(&dev->lock);
737
738 pdev = dev->pdev;
739 if (pdev)
740 return sprintf(page, "%s\n", dev_name(&pdev->dev));
741
742 return sprintf(page, "gpio-sim.%d\n", dev->id);
743}
744
745CONFIGFS_ATTR_RO(gpio_sim_device_config_, dev_name);
746
747static ssize_t
748gpio_sim_device_config_live_show(struct config_item *item, char *page)
749{
750 struct gpio_sim_device *dev = to_gpio_sim_device(item);
751 bool live;
752
753 scoped_guard(mutex, &dev->lock)
754 live = gpio_sim_device_is_live(dev);
755
756 return sprintf(page, "%c\n", live ? '1' : '0');
757}
758
759static unsigned int gpio_sim_get_line_names_size(struct gpio_sim_bank *bank)
760{
761 struct gpio_sim_line *line;
762 unsigned int size = 0;
763
764 list_for_each_entry(line, &bank->line_list, siblings) {
765 if (!line->name || (line->offset >= bank->num_lines))
766 continue;
767
768 size = max(size, line->offset + 1);
769 }
770
771 return size;
772}
773
774static void
775gpio_sim_set_line_names(struct gpio_sim_bank *bank, char **line_names)
776{
777 struct gpio_sim_line *line;
778
779 list_for_each_entry(line, &bank->line_list, siblings) {
780 if (!line->name || (line->offset >= bank->num_lines))
781 continue;
782
783 line_names[line->offset] = line->name;
784 }
785}
786
787static void gpio_sim_remove_hogs(struct gpio_sim_device *dev)
788{
789 struct gpiod_hog *hog;
790
791 if (!dev->hogs)
792 return;
793
794 gpiod_remove_hogs(dev->hogs);
795
796 for (hog = dev->hogs; hog->chip_label; hog++) {
797 kfree(hog->chip_label);
798 kfree(hog->line_name);
799 }
800
801 kfree(dev->hogs);
802 dev->hogs = NULL;
803}
804
805static int gpio_sim_add_hogs(struct gpio_sim_device *dev)
806{
807 unsigned int num_hogs = 0, idx = 0;
808 struct gpio_sim_bank *bank;
809 struct gpio_sim_line *line;
810 struct gpiod_hog *hog;
811
812 list_for_each_entry(bank, &dev->bank_list, siblings) {
813 list_for_each_entry(line, &bank->line_list, siblings) {
814 if (line->offset >= bank->num_lines)
815 continue;
816
817 if (line->hog)
818 num_hogs++;
819 }
820 }
821
822 if (!num_hogs)
823 return 0;
824
825 /* Allocate one more for the sentinel. */
826 dev->hogs = kcalloc(num_hogs + 1, sizeof(*dev->hogs), GFP_KERNEL);
827 if (!dev->hogs)
828 return -ENOMEM;
829
830 list_for_each_entry(bank, &dev->bank_list, siblings) {
831 list_for_each_entry(line, &bank->line_list, siblings) {
832 if (line->offset >= bank->num_lines)
833 continue;
834
835 if (!line->hog)
836 continue;
837
838 hog = &dev->hogs[idx++];
839
840 /*
841 * We need to make this string manually because at this
842 * point the device doesn't exist yet and so dev_name()
843 * is not available.
844 */
845 if (gpio_sim_bank_has_label(bank))
846 hog->chip_label = kstrdup(bank->label,
847 GFP_KERNEL);
848 else
849 hog->chip_label = kasprintf(GFP_KERNEL,
850 "gpio-sim.%u:%pfwP",
851 dev->id,
852 bank->swnode);
853 if (!hog->chip_label) {
854 gpio_sim_remove_hogs(dev);
855 return -ENOMEM;
856 }
857
858 /*
859 * We need to duplicate this because the hog config
860 * item can be removed at any time (and we can't block
861 * it) and gpiolib doesn't make a deep copy of the hog
862 * data.
863 */
864 if (line->hog->name) {
865 hog->line_name = kstrdup(line->hog->name,
866 GFP_KERNEL);
867 if (!hog->line_name) {
868 gpio_sim_remove_hogs(dev);
869 return -ENOMEM;
870 }
871 }
872
873 hog->chip_hwnum = line->offset;
874 hog->dflags = line->hog->dir;
875 }
876 }
877
878 gpiod_add_hogs(dev->hogs);
879
880 return 0;
881}
882
883static struct fwnode_handle *
884gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank,
885 struct fwnode_handle *parent)
886{
887 struct property_entry properties[GPIO_SIM_PROP_MAX];
888 unsigned int prop_idx = 0, line_names_size;
889 char **line_names __free(kfree) = NULL;
890
891 memset(properties, 0, sizeof(properties));
892
893 properties[prop_idx++] = PROPERTY_ENTRY_U32("ngpios", bank->num_lines);
894
895 if (gpio_sim_bank_has_label(bank))
896 properties[prop_idx++] = PROPERTY_ENTRY_STRING("gpio-sim,label",
897 bank->label);
898
899 line_names_size = gpio_sim_get_line_names_size(bank);
900 if (line_names_size) {
901 line_names = kcalloc(line_names_size, sizeof(*line_names),
902 GFP_KERNEL);
903 if (!line_names)
904 return ERR_PTR(-ENOMEM);
905
906 gpio_sim_set_line_names(bank, line_names);
907
908 properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
909 "gpio-line-names",
910 line_names, line_names_size);
911 }
912
913 return fwnode_create_software_node(properties, parent);
914}
915
916static void gpio_sim_remove_swnode_recursive(struct fwnode_handle *swnode)
917{
918 struct fwnode_handle *child;
919
920 fwnode_for_each_child_node(swnode, child)
921 fwnode_remove_software_node(child);
922
923 fwnode_remove_software_node(swnode);
924}
925
926static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev)
927{
928 struct gpio_sim_bank *this, *pos;
929
930 list_for_each_entry(this, &dev->bank_list, siblings) {
931 list_for_each_entry(pos, &dev->bank_list, siblings) {
932 if (this == pos || (!this->label || !pos->label))
933 continue;
934
935 if (strcmp(this->label, pos->label) == 0)
936 return true;
937 }
938 }
939
940 return false;
941}
942
943static int gpio_sim_device_activate(struct gpio_sim_device *dev)
944{
945 struct platform_device_info pdevinfo;
946 struct fwnode_handle *swnode;
947 struct platform_device *pdev;
948 struct gpio_sim_bank *bank;
949 int ret;
950
951 lockdep_assert_held(&dev->lock);
952
953 if (list_empty(&dev->bank_list))
954 return -ENODATA;
955
956 /*
957 * Non-unique GPIO device labels are a corner-case we don't support
958 * as it would interfere with machine hogging mechanism and has little
959 * use in real life.
960 */
961 if (gpio_sim_bank_labels_non_unique(dev))
962 return -EINVAL;
963
964 memset(&pdevinfo, 0, sizeof(pdevinfo));
965
966 swnode = fwnode_create_software_node(NULL, NULL);
967 if (IS_ERR(swnode))
968 return PTR_ERR(swnode);
969
970 list_for_each_entry(bank, &dev->bank_list, siblings) {
971 bank->swnode = gpio_sim_make_bank_swnode(bank, swnode);
972 if (IS_ERR(bank->swnode)) {
973 ret = PTR_ERR(bank->swnode);
974 gpio_sim_remove_swnode_recursive(swnode);
975 return ret;
976 }
977 }
978
979 ret = gpio_sim_add_hogs(dev);
980 if (ret) {
981 gpio_sim_remove_swnode_recursive(swnode);
982 return ret;
983 }
984
985 pdevinfo.name = "gpio-sim";
986 pdevinfo.fwnode = swnode;
987 pdevinfo.id = dev->id;
988
989 reinit_completion(&dev->probe_completion);
990 dev->driver_bound = false;
991 bus_register_notifier(&platform_bus_type, &dev->bus_notifier);
992
993 pdev = platform_device_register_full(&pdevinfo);
994 if (IS_ERR(pdev)) {
995 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier);
996 gpio_sim_remove_hogs(dev);
997 gpio_sim_remove_swnode_recursive(swnode);
998 return PTR_ERR(pdev);
999 }
1000
1001 wait_for_completion(&dev->probe_completion);
1002 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier);
1003
1004 if (!dev->driver_bound) {
1005 /* Probe failed, check kernel log. */
1006 platform_device_unregister(pdev);
1007 gpio_sim_remove_hogs(dev);
1008 gpio_sim_remove_swnode_recursive(swnode);
1009 return -ENXIO;
1010 }
1011
1012 dev->pdev = pdev;
1013
1014 return 0;
1015}
1016
1017static void gpio_sim_device_deactivate(struct gpio_sim_device *dev)
1018{
1019 struct fwnode_handle *swnode;
1020
1021 lockdep_assert_held(&dev->lock);
1022
1023 swnode = dev_fwnode(&dev->pdev->dev);
1024 platform_device_unregister(dev->pdev);
1025 gpio_sim_remove_hogs(dev);
1026 gpio_sim_remove_swnode_recursive(swnode);
1027 dev->pdev = NULL;
1028}
1029
1030static void
1031gpio_sim_device_lockup_configfs(struct gpio_sim_device *dev, bool lock)
1032{
1033 struct configfs_subsystem *subsys = dev->group.cg_subsys;
1034 struct gpio_sim_bank *bank;
1035 struct gpio_sim_line *line;
1036 struct config_item *item;
1037
1038 /*
1039 * The device only needs to depend on leaf entries. This is
1040 * sufficient to lock up all the configfs entries that the
1041 * instantiated, alive device depends on.
1042 */
1043 list_for_each_entry(bank, &dev->bank_list, siblings) {
1044 list_for_each_entry(line, &bank->line_list, siblings) {
1045 item = line->hog ? &line->hog->item
1046 : &line->group.cg_item;
1047
1048 if (lock)
1049 WARN_ON(configfs_depend_item_unlocked(subsys,
1050 item));
1051 else
1052 configfs_undepend_item_unlocked(item);
1053 }
1054 }
1055}
1056
1057static ssize_t
1058gpio_sim_device_config_live_store(struct config_item *item,
1059 const char *page, size_t count)
1060{
1061 struct gpio_sim_device *dev = to_gpio_sim_device(item);
1062 bool live;
1063 int ret;
1064
1065 ret = kstrtobool(page, &live);
1066 if (ret)
1067 return ret;
1068
1069 if (live)
1070 gpio_sim_device_lockup_configfs(dev, true);
1071
1072 scoped_guard(mutex, &dev->lock) {
1073 if (live == gpio_sim_device_is_live(dev))
1074 ret = -EPERM;
1075 else if (live)
1076 ret = gpio_sim_device_activate(dev);
1077 else
1078 gpio_sim_device_deactivate(dev);
1079 }
1080
1081 /*
1082 * Undepend is required only if device disablement (live == 0)
1083 * succeeds or if device enablement (live == 1) fails.
1084 */
1085 if (live == !!ret)
1086 gpio_sim_device_lockup_configfs(dev, false);
1087
1088 return ret ?: count;
1089}
1090
1091CONFIGFS_ATTR(gpio_sim_device_config_, live);
1092
1093static struct configfs_attribute *gpio_sim_device_config_attrs[] = {
1094 &gpio_sim_device_config_attr_dev_name,
1095 &gpio_sim_device_config_attr_live,
1096 NULL
1097};
1098
1099struct gpio_sim_chip_name_ctx {
1100 struct fwnode_handle *swnode;
1101 char *page;
1102};
1103
1104static int gpio_sim_emit_chip_name(struct device *dev, void *data)
1105{
1106 struct gpio_sim_chip_name_ctx *ctx = data;
1107
1108 /* This would be the sysfs device exported in /sys/class/gpio. */
1109 if (dev->class)
1110 return 0;
1111
1112 if (device_match_fwnode(dev, ctx->swnode))
1113 return sprintf(ctx->page, "%s\n", dev_name(dev));
1114
1115 return 0;
1116}
1117
1118static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item,
1119 char *page)
1120{
1121 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1122 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1123 struct gpio_sim_chip_name_ctx ctx = { bank->swnode, page };
1124
1125 guard(mutex)(&dev->lock);
1126
1127 if (gpio_sim_device_is_live(dev))
1128 return device_for_each_child(&dev->pdev->dev, &ctx,
1129 gpio_sim_emit_chip_name);
1130
1131 return sprintf(page, "none\n");
1132}
1133
1134CONFIGFS_ATTR_RO(gpio_sim_bank_config_, chip_name);
1135
1136static ssize_t
1137gpio_sim_bank_config_label_show(struct config_item *item, char *page)
1138{
1139 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1140 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1141
1142 guard(mutex)(&dev->lock);
1143
1144 return sprintf(page, "%s\n", bank->label ?: "");
1145}
1146
1147static ssize_t gpio_sim_bank_config_label_store(struct config_item *item,
1148 const char *page, size_t count)
1149{
1150 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1151 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1152 char *trimmed;
1153
1154 guard(mutex)(&dev->lock);
1155
1156 if (gpio_sim_device_is_live(dev))
1157 return -EBUSY;
1158
1159 trimmed = gpio_sim_strdup_trimmed(page, count);
1160 if (!trimmed)
1161 return -ENOMEM;
1162
1163 kfree(bank->label);
1164 bank->label = trimmed;
1165
1166 return count;
1167}
1168
1169CONFIGFS_ATTR(gpio_sim_bank_config_, label);
1170
1171static ssize_t
1172gpio_sim_bank_config_num_lines_show(struct config_item *item, char *page)
1173{
1174 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1175 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1176
1177 guard(mutex)(&dev->lock);
1178
1179 return sprintf(page, "%u\n", bank->num_lines);
1180}
1181
1182static ssize_t
1183gpio_sim_bank_config_num_lines_store(struct config_item *item,
1184 const char *page, size_t count)
1185{
1186 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1187 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1188 unsigned int num_lines;
1189 int ret;
1190
1191 ret = kstrtouint(page, 0, &num_lines);
1192 if (ret)
1193 return ret;
1194
1195 if (num_lines == 0)
1196 return -EINVAL;
1197
1198 guard(mutex)(&dev->lock);
1199
1200 if (gpio_sim_device_is_live(dev))
1201 return -EBUSY;
1202
1203 bank->num_lines = num_lines;
1204
1205 return count;
1206}
1207
1208CONFIGFS_ATTR(gpio_sim_bank_config_, num_lines);
1209
1210static struct configfs_attribute *gpio_sim_bank_config_attrs[] = {
1211 &gpio_sim_bank_config_attr_chip_name,
1212 &gpio_sim_bank_config_attr_label,
1213 &gpio_sim_bank_config_attr_num_lines,
1214 NULL
1215};
1216
1217static ssize_t
1218gpio_sim_line_config_name_show(struct config_item *item, char *page)
1219{
1220 struct gpio_sim_line *line = to_gpio_sim_line(item);
1221 struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
1222
1223 guard(mutex)(&dev->lock);
1224
1225 return sprintf(page, "%s\n", line->name ?: "");
1226}
1227
1228static ssize_t gpio_sim_line_config_name_store(struct config_item *item,
1229 const char *page, size_t count)
1230{
1231 struct gpio_sim_line *line = to_gpio_sim_line(item);
1232 struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
1233 char *trimmed;
1234
1235 guard(mutex)(&dev->lock);
1236
1237 if (gpio_sim_device_is_live(dev))
1238 return -EBUSY;
1239
1240 trimmed = gpio_sim_strdup_trimmed(page, count);
1241 if (!trimmed)
1242 return -ENOMEM;
1243
1244 kfree(line->name);
1245 line->name = trimmed;
1246
1247 return count;
1248}
1249
1250CONFIGFS_ATTR(gpio_sim_line_config_, name);
1251
1252static struct configfs_attribute *gpio_sim_line_config_attrs[] = {
1253 &gpio_sim_line_config_attr_name,
1254 NULL
1255};
1256
1257static ssize_t gpio_sim_hog_config_name_show(struct config_item *item,
1258 char *page)
1259{
1260 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1261 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1262
1263 guard(mutex)(&dev->lock);
1264
1265 return sprintf(page, "%s\n", hog->name ?: "");
1266}
1267
1268static ssize_t gpio_sim_hog_config_name_store(struct config_item *item,
1269 const char *page, size_t count)
1270{
1271 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1272 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1273 char *trimmed;
1274
1275 guard(mutex)(&dev->lock);
1276
1277 if (gpio_sim_device_is_live(dev))
1278 return -EBUSY;
1279
1280 trimmed = gpio_sim_strdup_trimmed(page, count);
1281 if (!trimmed)
1282 return -ENOMEM;
1283
1284 kfree(hog->name);
1285 hog->name = trimmed;
1286
1287 return count;
1288}
1289
1290CONFIGFS_ATTR(gpio_sim_hog_config_, name);
1291
1292static ssize_t gpio_sim_hog_config_direction_show(struct config_item *item,
1293 char *page)
1294{
1295 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1296 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1297 char *repr;
1298 int dir;
1299
1300 scoped_guard(mutex, &dev->lock)
1301 dir = hog->dir;
1302
1303 switch (dir) {
1304 case GPIOD_IN:
1305 repr = "input";
1306 break;
1307 case GPIOD_OUT_HIGH:
1308 repr = "output-high";
1309 break;
1310 case GPIOD_OUT_LOW:
1311 repr = "output-low";
1312 break;
1313 default:
1314 /* This would be a programmer bug. */
1315 WARN(1, "Unexpected hog direction value: %d", dir);
1316 return -EINVAL;
1317 }
1318
1319 return sprintf(page, "%s\n", repr);
1320}
1321
1322static ssize_t
1323gpio_sim_hog_config_direction_store(struct config_item *item,
1324 const char *page, size_t count)
1325{
1326 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1327 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1328 int dir;
1329
1330 guard(mutex)(&dev->lock);
1331
1332 if (gpio_sim_device_is_live(dev))
1333 return -EBUSY;
1334
1335 if (sysfs_streq(page, "input"))
1336 dir = GPIOD_IN;
1337 else if (sysfs_streq(page, "output-high"))
1338 dir = GPIOD_OUT_HIGH;
1339 else if (sysfs_streq(page, "output-low"))
1340 dir = GPIOD_OUT_LOW;
1341 else
1342 return -EINVAL;
1343
1344 hog->dir = dir;
1345
1346 return count;
1347}
1348
1349CONFIGFS_ATTR(gpio_sim_hog_config_, direction);
1350
1351static struct configfs_attribute *gpio_sim_hog_config_attrs[] = {
1352 &gpio_sim_hog_config_attr_name,
1353 &gpio_sim_hog_config_attr_direction,
1354 NULL
1355};
1356
1357static void gpio_sim_hog_config_item_release(struct config_item *item)
1358{
1359 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1360 struct gpio_sim_line *line = hog->parent;
1361 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1362
1363 scoped_guard(mutex, &dev->lock)
1364 line->hog = NULL;
1365
1366 kfree(hog->name);
1367 kfree(hog);
1368}
1369
1370static struct configfs_item_operations gpio_sim_hog_config_item_ops = {
1371 .release = gpio_sim_hog_config_item_release,
1372};
1373
1374static const struct config_item_type gpio_sim_hog_config_type = {
1375 .ct_item_ops = &gpio_sim_hog_config_item_ops,
1376 .ct_attrs = gpio_sim_hog_config_attrs,
1377 .ct_owner = THIS_MODULE,
1378};
1379
1380static struct config_item *
1381gpio_sim_line_config_make_hog_item(struct config_group *group, const char *name)
1382{
1383 struct gpio_sim_line *line = to_gpio_sim_line(&group->cg_item);
1384 struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
1385 struct gpio_sim_hog *hog;
1386
1387 if (strcmp(name, "hog") != 0)
1388 return ERR_PTR(-EINVAL);
1389
1390 guard(mutex)(&dev->lock);
1391
1392 hog = kzalloc(sizeof(*hog), GFP_KERNEL);
1393 if (!hog)
1394 return ERR_PTR(-ENOMEM);
1395
1396 config_item_init_type_name(&hog->item, name,
1397 &gpio_sim_hog_config_type);
1398
1399 hog->dir = GPIOD_IN;
1400 hog->name = NULL;
1401 hog->parent = line;
1402 line->hog = hog;
1403
1404 return &hog->item;
1405}
1406
1407static void gpio_sim_line_config_group_release(struct config_item *item)
1408{
1409 struct gpio_sim_line *line = to_gpio_sim_line(item);
1410 struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
1411
1412 scoped_guard(mutex, &dev->lock)
1413 list_del(&line->siblings);
1414
1415 kfree(line->name);
1416 kfree(line);
1417}
1418
1419static struct configfs_item_operations gpio_sim_line_config_item_ops = {
1420 .release = gpio_sim_line_config_group_release,
1421};
1422
1423static struct configfs_group_operations gpio_sim_line_config_group_ops = {
1424 .make_item = gpio_sim_line_config_make_hog_item,
1425};
1426
1427static const struct config_item_type gpio_sim_line_config_type = {
1428 .ct_item_ops = &gpio_sim_line_config_item_ops,
1429 .ct_group_ops = &gpio_sim_line_config_group_ops,
1430 .ct_attrs = gpio_sim_line_config_attrs,
1431 .ct_owner = THIS_MODULE,
1432};
1433
1434static struct config_group *
1435gpio_sim_bank_config_make_line_group(struct config_group *group,
1436 const char *name)
1437{
1438 struct gpio_sim_bank *bank = to_gpio_sim_bank(&group->cg_item);
1439 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1440 struct gpio_sim_line *line;
1441 unsigned int offset;
1442 int ret, nchar;
1443
1444 ret = sscanf(name, "line%u%n", &offset, &nchar);
1445 if (ret != 1 || nchar != strlen(name))
1446 return ERR_PTR(-EINVAL);
1447
1448 guard(mutex)(&dev->lock);
1449
1450 if (gpio_sim_device_is_live(dev))
1451 return ERR_PTR(-EBUSY);
1452
1453 line = kzalloc(sizeof(*line), GFP_KERNEL);
1454 if (!line)
1455 return ERR_PTR(-ENOMEM);
1456
1457 config_group_init_type_name(&line->group, name,
1458 &gpio_sim_line_config_type);
1459
1460 line->parent = bank;
1461 line->offset = offset;
1462 list_add_tail(&line->siblings, &bank->line_list);
1463
1464 return &line->group;
1465}
1466
1467static void gpio_sim_bank_config_group_release(struct config_item *item)
1468{
1469 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1470 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1471
1472 scoped_guard(mutex, &dev->lock)
1473 list_del(&bank->siblings);
1474
1475 kfree(bank->label);
1476 kfree(bank);
1477}
1478
1479static struct configfs_item_operations gpio_sim_bank_config_item_ops = {
1480 .release = gpio_sim_bank_config_group_release,
1481};
1482
1483static struct configfs_group_operations gpio_sim_bank_config_group_ops = {
1484 .make_group = gpio_sim_bank_config_make_line_group,
1485};
1486
1487static const struct config_item_type gpio_sim_bank_config_group_type = {
1488 .ct_item_ops = &gpio_sim_bank_config_item_ops,
1489 .ct_group_ops = &gpio_sim_bank_config_group_ops,
1490 .ct_attrs = gpio_sim_bank_config_attrs,
1491 .ct_owner = THIS_MODULE,
1492};
1493
1494static struct config_group *
1495gpio_sim_device_config_make_bank_group(struct config_group *group,
1496 const char *name)
1497{
1498 struct gpio_sim_device *dev = to_gpio_sim_device(&group->cg_item);
1499 struct gpio_sim_bank *bank;
1500
1501 guard(mutex)(&dev->lock);
1502
1503 if (gpio_sim_device_is_live(dev))
1504 return ERR_PTR(-EBUSY);
1505
1506 bank = kzalloc(sizeof(*bank), GFP_KERNEL);
1507 if (!bank)
1508 return ERR_PTR(-ENOMEM);
1509
1510 config_group_init_type_name(&bank->group, name,
1511 &gpio_sim_bank_config_group_type);
1512 bank->num_lines = 1;
1513 bank->parent = dev;
1514 INIT_LIST_HEAD(&bank->line_list);
1515 list_add_tail(&bank->siblings, &dev->bank_list);
1516
1517 return &bank->group;
1518}
1519
1520static void gpio_sim_device_config_group_release(struct config_item *item)
1521{
1522 struct gpio_sim_device *dev = to_gpio_sim_device(item);
1523
1524 scoped_guard(mutex, &dev->lock) {
1525 if (gpio_sim_device_is_live(dev))
1526 gpio_sim_device_deactivate(dev);
1527 }
1528
1529 mutex_destroy(&dev->lock);
1530 ida_free(&gpio_sim_ida, dev->id);
1531 kfree(dev);
1532}
1533
1534static struct configfs_item_operations gpio_sim_device_config_item_ops = {
1535 .release = gpio_sim_device_config_group_release,
1536};
1537
1538static struct configfs_group_operations gpio_sim_device_config_group_ops = {
1539 .make_group = gpio_sim_device_config_make_bank_group,
1540};
1541
1542static const struct config_item_type gpio_sim_device_config_group_type = {
1543 .ct_item_ops = &gpio_sim_device_config_item_ops,
1544 .ct_group_ops = &gpio_sim_device_config_group_ops,
1545 .ct_attrs = gpio_sim_device_config_attrs,
1546 .ct_owner = THIS_MODULE,
1547};
1548
1549static struct config_group *
1550gpio_sim_config_make_device_group(struct config_group *group, const char *name)
1551{
1552 int id;
1553
1554 struct gpio_sim_device *dev __free(kfree) = kzalloc(sizeof(*dev),
1555 GFP_KERNEL);
1556 if (!dev)
1557 return ERR_PTR(-ENOMEM);
1558
1559 id = ida_alloc(&gpio_sim_ida, GFP_KERNEL);
1560 if (id < 0)
1561 return ERR_PTR(id);
1562
1563 config_group_init_type_name(&dev->group, name,
1564 &gpio_sim_device_config_group_type);
1565 dev->id = id;
1566 mutex_init(&dev->lock);
1567 INIT_LIST_HEAD(&dev->bank_list);
1568
1569 dev->bus_notifier.notifier_call = gpio_sim_bus_notifier_call;
1570 init_completion(&dev->probe_completion);
1571
1572 return &no_free_ptr(dev)->group;
1573}
1574
1575static struct configfs_group_operations gpio_sim_config_group_ops = {
1576 .make_group = gpio_sim_config_make_device_group,
1577};
1578
1579static const struct config_item_type gpio_sim_config_type = {
1580 .ct_group_ops = &gpio_sim_config_group_ops,
1581 .ct_owner = THIS_MODULE,
1582};
1583
1584static struct configfs_subsystem gpio_sim_config_subsys = {
1585 .su_group = {
1586 .cg_item = {
1587 .ci_namebuf = "gpio-sim",
1588 .ci_type = &gpio_sim_config_type,
1589 },
1590 },
1591};
1592
1593static int __init gpio_sim_init(void)
1594{
1595 int ret;
1596
1597 ret = platform_driver_register(&gpio_sim_driver);
1598 if (ret) {
1599 pr_err("Error %d while registering the platform driver\n", ret);
1600 return ret;
1601 }
1602
1603 config_group_init(&gpio_sim_config_subsys.su_group);
1604 mutex_init(&gpio_sim_config_subsys.su_mutex);
1605 ret = configfs_register_subsystem(&gpio_sim_config_subsys);
1606 if (ret) {
1607 pr_err("Error %d while registering the configfs subsystem %s\n",
1608 ret, gpio_sim_config_subsys.su_group.cg_item.ci_namebuf);
1609 mutex_destroy(&gpio_sim_config_subsys.su_mutex);
1610 platform_driver_unregister(&gpio_sim_driver);
1611 return ret;
1612 }
1613
1614 return 0;
1615}
1616module_init(gpio_sim_init);
1617
1618static void __exit gpio_sim_exit(void)
1619{
1620 configfs_unregister_subsystem(&gpio_sim_config_subsys);
1621 mutex_destroy(&gpio_sim_config_subsys.su_mutex);
1622 platform_driver_unregister(&gpio_sim_driver);
1623}
1624module_exit(gpio_sim_exit);
1625
1626MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>");
1627MODULE_DESCRIPTION("GPIO Simulator Module");
1628MODULE_LICENSE("GPL");