Loading...
Note: File does not exist in v3.5.6.
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/bitmap.h>
11#include <linux/completion.h>
12#include <linux/configfs.h>
13#include <linux/device.h>
14#include <linux/gpio/driver.h>
15#include <linux/gpio/machine.h>
16#include <linux/idr.h>
17#include <linux/interrupt.h>
18#include <linux/irq.h>
19#include <linux/irq_sim.h>
20#include <linux/list.h>
21#include <linux/mod_devicetable.h>
22#include <linux/module.h>
23#include <linux/mutex.h>
24#include <linux/notifier.h>
25#include <linux/platform_device.h>
26#include <linux/property.h>
27#include <linux/slab.h>
28#include <linux/string.h>
29#include <linux/string_helpers.h>
30#include <linux/sysfs.h>
31
32#include "gpiolib.h"
33
34#define GPIO_SIM_NGPIO_MAX 1024
35#define GPIO_SIM_PROP_MAX 4 /* Max 3 properties + sentinel. */
36#define GPIO_SIM_NUM_ATTRS 3 /* value, pull and sentinel */
37
38static DEFINE_IDA(gpio_sim_ida);
39
40struct gpio_sim_chip {
41 struct gpio_chip gc;
42 unsigned long *direction_map;
43 unsigned long *value_map;
44 unsigned long *pull_map;
45 struct irq_domain *irq_sim;
46 struct mutex lock;
47 const struct attribute_group **attr_groups;
48};
49
50struct gpio_sim_attribute {
51 struct device_attribute dev_attr;
52 unsigned int offset;
53};
54
55static struct gpio_sim_attribute *
56to_gpio_sim_attr(struct device_attribute *dev_attr)
57{
58 return container_of(dev_attr, struct gpio_sim_attribute, dev_attr);
59}
60
61static int gpio_sim_apply_pull(struct gpio_sim_chip *chip,
62 unsigned int offset, int value)
63{
64 int irq, irq_type, ret;
65 struct gpio_desc *desc;
66 struct gpio_chip *gc;
67
68 gc = &chip->gc;
69 desc = &gc->gpiodev->descs[offset];
70
71 mutex_lock(&chip->lock);
72
73 if (test_bit(FLAG_REQUESTED, &desc->flags) &&
74 !test_bit(FLAG_IS_OUT, &desc->flags)) {
75 if (value == !!test_bit(offset, chip->value_map))
76 goto set_pull;
77
78 /*
79 * This is fine - it just means, nobody is listening
80 * for interrupts on this line, otherwise
81 * irq_create_mapping() would have been called from
82 * the to_irq() callback.
83 */
84 irq = irq_find_mapping(chip->irq_sim, offset);
85 if (!irq)
86 goto set_value;
87
88 irq_type = irq_get_trigger_type(irq);
89
90 if ((value && (irq_type & IRQ_TYPE_EDGE_RISING)) ||
91 (!value && (irq_type & IRQ_TYPE_EDGE_FALLING))) {
92 ret = irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING,
93 true);
94 if (ret)
95 goto set_pull;
96 }
97 }
98
99set_value:
100 /* Change the value unless we're actively driving the line. */
101 if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
102 !test_bit(FLAG_IS_OUT, &desc->flags))
103 __assign_bit(offset, chip->value_map, value);
104
105set_pull:
106 __assign_bit(offset, chip->pull_map, value);
107 mutex_unlock(&chip->lock);
108 return 0;
109}
110
111static int gpio_sim_get(struct gpio_chip *gc, unsigned int offset)
112{
113 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
114 int ret;
115
116 mutex_lock(&chip->lock);
117 ret = !!test_bit(offset, chip->value_map);
118 mutex_unlock(&chip->lock);
119
120 return ret;
121}
122
123static void gpio_sim_set(struct gpio_chip *gc, unsigned int offset, int value)
124{
125 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
126
127 mutex_lock(&chip->lock);
128 __assign_bit(offset, chip->value_map, value);
129 mutex_unlock(&chip->lock);
130}
131
132static int gpio_sim_get_multiple(struct gpio_chip *gc,
133 unsigned long *mask, unsigned long *bits)
134{
135 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
136
137 mutex_lock(&chip->lock);
138 bitmap_replace(bits, bits, chip->value_map, mask, gc->ngpio);
139 mutex_unlock(&chip->lock);
140
141 return 0;
142}
143
144static void gpio_sim_set_multiple(struct gpio_chip *gc,
145 unsigned long *mask, unsigned long *bits)
146{
147 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
148
149 mutex_lock(&chip->lock);
150 bitmap_replace(chip->value_map, chip->value_map, bits, mask, gc->ngpio);
151 mutex_unlock(&chip->lock);
152}
153
154static int gpio_sim_direction_output(struct gpio_chip *gc,
155 unsigned int offset, int value)
156{
157 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
158
159 mutex_lock(&chip->lock);
160 __clear_bit(offset, chip->direction_map);
161 __assign_bit(offset, chip->value_map, value);
162 mutex_unlock(&chip->lock);
163
164 return 0;
165}
166
167static int gpio_sim_direction_input(struct gpio_chip *gc, unsigned int offset)
168{
169 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
170
171 mutex_lock(&chip->lock);
172 __set_bit(offset, chip->direction_map);
173 mutex_unlock(&chip->lock);
174
175 return 0;
176}
177
178static int gpio_sim_get_direction(struct gpio_chip *gc, unsigned int offset)
179{
180 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
181 int direction;
182
183 mutex_lock(&chip->lock);
184 direction = !!test_bit(offset, chip->direction_map);
185 mutex_unlock(&chip->lock);
186
187 return direction ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT;
188}
189
190static int gpio_sim_set_config(struct gpio_chip *gc,
191 unsigned int offset, unsigned long config)
192{
193 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
194
195 switch (pinconf_to_config_param(config)) {
196 case PIN_CONFIG_BIAS_PULL_UP:
197 return gpio_sim_apply_pull(chip, offset, 1);
198 case PIN_CONFIG_BIAS_PULL_DOWN:
199 return gpio_sim_apply_pull(chip, offset, 0);
200 default:
201 break;
202 }
203
204 return -ENOTSUPP;
205}
206
207static int gpio_sim_to_irq(struct gpio_chip *gc, unsigned int offset)
208{
209 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
210
211 return irq_create_mapping(chip->irq_sim, offset);
212}
213
214static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset)
215{
216 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
217
218 mutex_lock(&chip->lock);
219 __assign_bit(offset, chip->value_map, !!test_bit(offset, chip->pull_map));
220 mutex_unlock(&chip->lock);
221}
222
223static ssize_t gpio_sim_sysfs_val_show(struct device *dev,
224 struct device_attribute *attr, char *buf)
225{
226 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
227 struct gpio_sim_chip *chip = dev_get_drvdata(dev);
228 int val;
229
230 mutex_lock(&chip->lock);
231 val = !!test_bit(line_attr->offset, chip->value_map);
232 mutex_unlock(&chip->lock);
233
234 return sysfs_emit(buf, "%d\n", val);
235}
236
237static ssize_t gpio_sim_sysfs_val_store(struct device *dev,
238 struct device_attribute *attr,
239 const char *buf, size_t count)
240{
241 /*
242 * Not assigning this function will result in write() returning -EIO
243 * which is confusing. Return -EPERM explicitly.
244 */
245 return -EPERM;
246}
247
248static const char *const gpio_sim_sysfs_pull_strings[] = {
249 [0] = "pull-down",
250 [1] = "pull-up",
251};
252
253static ssize_t gpio_sim_sysfs_pull_show(struct device *dev,
254 struct device_attribute *attr,
255 char *buf)
256{
257 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
258 struct gpio_sim_chip *chip = dev_get_drvdata(dev);
259 int pull;
260
261 mutex_lock(&chip->lock);
262 pull = !!test_bit(line_attr->offset, chip->pull_map);
263 mutex_unlock(&chip->lock);
264
265 return sysfs_emit(buf, "%s\n", gpio_sim_sysfs_pull_strings[pull]);
266}
267
268static ssize_t gpio_sim_sysfs_pull_store(struct device *dev,
269 struct device_attribute *attr,
270 const char *buf, size_t len)
271{
272 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
273 struct gpio_sim_chip *chip = dev_get_drvdata(dev);
274 int ret, pull;
275
276 pull = sysfs_match_string(gpio_sim_sysfs_pull_strings, buf);
277 if (pull < 0)
278 return pull;
279
280 ret = gpio_sim_apply_pull(chip, line_attr->offset, pull);
281 if (ret)
282 return ret;
283
284 return len;
285}
286
287static void gpio_sim_mutex_destroy(void *data)
288{
289 struct mutex *lock = data;
290
291 mutex_destroy(lock);
292}
293
294static void gpio_sim_sysfs_remove(void *data)
295{
296 struct gpio_sim_chip *chip = data;
297
298 sysfs_remove_groups(&chip->gc.gpiodev->dev.kobj, chip->attr_groups);
299}
300
301static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip)
302{
303 struct device_attribute *val_dev_attr, *pull_dev_attr;
304 struct gpio_sim_attribute *val_attr, *pull_attr;
305 unsigned int num_lines = chip->gc.ngpio;
306 struct device *dev = chip->gc.parent;
307 struct attribute_group *attr_group;
308 struct attribute **attrs;
309 int i, ret;
310
311 chip->attr_groups = devm_kcalloc(dev, sizeof(*chip->attr_groups),
312 num_lines + 1, GFP_KERNEL);
313 if (!chip->attr_groups)
314 return -ENOMEM;
315
316 for (i = 0; i < num_lines; i++) {
317 attr_group = devm_kzalloc(dev, sizeof(*attr_group), GFP_KERNEL);
318 attrs = devm_kcalloc(dev, GPIO_SIM_NUM_ATTRS, sizeof(*attrs),
319 GFP_KERNEL);
320 val_attr = devm_kzalloc(dev, sizeof(*val_attr), GFP_KERNEL);
321 pull_attr = devm_kzalloc(dev, sizeof(*pull_attr), GFP_KERNEL);
322 if (!attr_group || !attrs || !val_attr || !pull_attr)
323 return -ENOMEM;
324
325 attr_group->name = devm_kasprintf(dev, GFP_KERNEL,
326 "sim_gpio%u", i);
327 if (!attr_group->name)
328 return -ENOMEM;
329
330 val_attr->offset = pull_attr->offset = i;
331
332 val_dev_attr = &val_attr->dev_attr;
333 pull_dev_attr = &pull_attr->dev_attr;
334
335 sysfs_attr_init(&val_dev_attr->attr);
336 sysfs_attr_init(&pull_dev_attr->attr);
337
338 val_dev_attr->attr.name = "value";
339 pull_dev_attr->attr.name = "pull";
340
341 val_dev_attr->attr.mode = pull_dev_attr->attr.mode = 0644;
342
343 val_dev_attr->show = gpio_sim_sysfs_val_show;
344 val_dev_attr->store = gpio_sim_sysfs_val_store;
345 pull_dev_attr->show = gpio_sim_sysfs_pull_show;
346 pull_dev_attr->store = gpio_sim_sysfs_pull_store;
347
348 attrs[0] = &val_dev_attr->attr;
349 attrs[1] = &pull_dev_attr->attr;
350
351 attr_group->attrs = attrs;
352 chip->attr_groups[i] = attr_group;
353 }
354
355 ret = sysfs_create_groups(&chip->gc.gpiodev->dev.kobj,
356 chip->attr_groups);
357 if (ret)
358 return ret;
359
360 return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip);
361}
362
363static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
364{
365 struct gpio_sim_chip *chip;
366 struct gpio_chip *gc;
367 const char *label;
368 u32 num_lines;
369 int ret;
370
371 ret = fwnode_property_read_u32(swnode, "ngpios", &num_lines);
372 if (ret)
373 return ret;
374
375 if (num_lines > GPIO_SIM_NGPIO_MAX)
376 return -ERANGE;
377
378 ret = fwnode_property_read_string(swnode, "gpio-sim,label", &label);
379 if (ret) {
380 label = devm_kasprintf(dev, GFP_KERNEL, "%s-%s",
381 dev_name(dev), fwnode_get_name(swnode));
382 if (!label)
383 return -ENOMEM;
384 }
385
386 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
387 if (!chip)
388 return -ENOMEM;
389
390 chip->direction_map = devm_bitmap_alloc(dev, num_lines, GFP_KERNEL);
391 if (!chip->direction_map)
392 return -ENOMEM;
393
394 /* Default to input mode. */
395 bitmap_fill(chip->direction_map, num_lines);
396
397 chip->value_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL);
398 if (!chip->value_map)
399 return -ENOMEM;
400
401 chip->pull_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL);
402 if (!chip->pull_map)
403 return -ENOMEM;
404
405 chip->irq_sim = devm_irq_domain_create_sim(dev, NULL, num_lines);
406 if (IS_ERR(chip->irq_sim))
407 return PTR_ERR(chip->irq_sim);
408
409 mutex_init(&chip->lock);
410 ret = devm_add_action_or_reset(dev, gpio_sim_mutex_destroy,
411 &chip->lock);
412 if (ret)
413 return ret;
414
415 gc = &chip->gc;
416 gc->base = -1;
417 gc->ngpio = num_lines;
418 gc->label = label;
419 gc->owner = THIS_MODULE;
420 gc->parent = dev;
421 gc->fwnode = swnode;
422 gc->get = gpio_sim_get;
423 gc->set = gpio_sim_set;
424 gc->get_multiple = gpio_sim_get_multiple;
425 gc->set_multiple = gpio_sim_set_multiple;
426 gc->direction_output = gpio_sim_direction_output;
427 gc->direction_input = gpio_sim_direction_input;
428 gc->get_direction = gpio_sim_get_direction;
429 gc->set_config = gpio_sim_set_config;
430 gc->to_irq = gpio_sim_to_irq;
431 gc->free = gpio_sim_free;
432
433 ret = devm_gpiochip_add_data(dev, gc, chip);
434 if (ret)
435 return ret;
436
437 /* Used by sysfs and configfs callbacks. */
438 dev_set_drvdata(&gc->gpiodev->dev, chip);
439
440 return gpio_sim_setup_sysfs(chip);
441}
442
443static int gpio_sim_probe(struct platform_device *pdev)
444{
445 struct device *dev = &pdev->dev;
446 struct fwnode_handle *swnode;
447 int ret;
448
449 device_for_each_child_node(dev, swnode) {
450 ret = gpio_sim_add_bank(swnode, dev);
451 if (ret) {
452 fwnode_handle_put(swnode);
453 return ret;
454 }
455 }
456
457 return 0;
458}
459
460static const struct of_device_id gpio_sim_of_match[] = {
461 { .compatible = "gpio-simulator" },
462 { }
463};
464MODULE_DEVICE_TABLE(of, gpio_sim_of_match);
465
466static struct platform_driver gpio_sim_driver = {
467 .driver = {
468 .name = "gpio-sim",
469 .of_match_table = gpio_sim_of_match,
470 },
471 .probe = gpio_sim_probe,
472};
473
474struct gpio_sim_device {
475 struct config_group group;
476
477 /*
478 * If pdev is NULL, the device is 'pending' (waiting for configuration).
479 * Once the pointer is assigned, the device has been created and the
480 * item is 'live'.
481 */
482 struct platform_device *pdev;
483 int id;
484
485 /*
486 * Each configfs filesystem operation is protected with the subsystem
487 * mutex. Each separate attribute is protected with the buffer mutex.
488 * This structure however can be modified by callbacks of different
489 * attributes so we need another lock.
490 *
491 * We use this lock fo protecting all data structures owned by this
492 * object too.
493 */
494 struct mutex lock;
495
496 /*
497 * This is used to synchronously wait for the driver's probe to complete
498 * and notify the user-space about any errors.
499 */
500 struct notifier_block bus_notifier;
501 struct completion probe_completion;
502 bool driver_bound;
503
504 struct gpiod_hog *hogs;
505
506 struct list_head bank_list;
507};
508
509/* This is called with dev->lock already taken. */
510static int gpio_sim_bus_notifier_call(struct notifier_block *nb,
511 unsigned long action, void *data)
512{
513 struct gpio_sim_device *simdev = container_of(nb,
514 struct gpio_sim_device,
515 bus_notifier);
516 struct device *dev = data;
517 char devname[32];
518
519 snprintf(devname, sizeof(devname), "gpio-sim.%u", simdev->id);
520
521 if (strcmp(dev_name(dev), devname) == 0) {
522 if (action == BUS_NOTIFY_BOUND_DRIVER)
523 simdev->driver_bound = true;
524 else if (action == BUS_NOTIFY_DRIVER_NOT_BOUND)
525 simdev->driver_bound = false;
526 else
527 return NOTIFY_DONE;
528
529 complete(&simdev->probe_completion);
530 return NOTIFY_OK;
531 }
532
533 return NOTIFY_DONE;
534}
535
536static struct gpio_sim_device *to_gpio_sim_device(struct config_item *item)
537{
538 struct config_group *group = to_config_group(item);
539
540 return container_of(group, struct gpio_sim_device, group);
541}
542
543struct gpio_sim_bank {
544 struct config_group group;
545
546 /*
547 * We could have used the ci_parent field of the config_item but
548 * configfs is stupid and calls the item's release callback after
549 * already having cleared the parent pointer even though the parent
550 * is guaranteed to survive the child...
551 *
552 * So we need to store the pointer to the parent struct here. We can
553 * dereference it anywhere we need with no checks and no locking as
554 * it's guaranteed to survive the children and protected by configfs
555 * locks.
556 *
557 * Same for other structures.
558 */
559 struct gpio_sim_device *parent;
560 struct list_head siblings;
561
562 char *label;
563 unsigned int num_lines;
564
565 struct list_head line_list;
566
567 struct fwnode_handle *swnode;
568};
569
570static struct gpio_sim_bank *to_gpio_sim_bank(struct config_item *item)
571{
572 struct config_group *group = to_config_group(item);
573
574 return container_of(group, struct gpio_sim_bank, group);
575}
576
577static bool gpio_sim_bank_has_label(struct gpio_sim_bank *bank)
578{
579 return bank->label && *bank->label;
580}
581
582static struct gpio_sim_device *
583gpio_sim_bank_get_device(struct gpio_sim_bank *bank)
584{
585 return bank->parent;
586}
587
588struct gpio_sim_hog;
589
590struct gpio_sim_line {
591 struct config_group group;
592
593 struct gpio_sim_bank *parent;
594 struct list_head siblings;
595
596 unsigned int offset;
597 char *name;
598
599 /* There can only be one hog per line. */
600 struct gpio_sim_hog *hog;
601};
602
603static struct gpio_sim_line *to_gpio_sim_line(struct config_item *item)
604{
605 struct config_group *group = to_config_group(item);
606
607 return container_of(group, struct gpio_sim_line, group);
608}
609
610static struct gpio_sim_device *
611gpio_sim_line_get_device(struct gpio_sim_line *line)
612{
613 struct gpio_sim_bank *bank = line->parent;
614
615 return gpio_sim_bank_get_device(bank);
616}
617
618struct gpio_sim_hog {
619 struct config_item item;
620 struct gpio_sim_line *parent;
621
622 char *name;
623 int dir;
624};
625
626static struct gpio_sim_hog *to_gpio_sim_hog(struct config_item *item)
627{
628 return container_of(item, struct gpio_sim_hog, item);
629}
630
631static struct gpio_sim_device *gpio_sim_hog_get_device(struct gpio_sim_hog *hog)
632{
633 struct gpio_sim_line *line = hog->parent;
634
635 return gpio_sim_line_get_device(line);
636}
637
638static bool gpio_sim_device_is_live_unlocked(struct gpio_sim_device *dev)
639{
640 return !!dev->pdev;
641}
642
643static char *gpio_sim_strdup_trimmed(const char *str, size_t count)
644{
645 char *dup, *trimmed;
646
647 dup = kstrndup(str, count, GFP_KERNEL);
648 if (!dup)
649 return NULL;
650
651 trimmed = strstrip(dup);
652 memmove(dup, trimmed, strlen(trimmed) + 1);
653
654 return dup;
655}
656
657static ssize_t gpio_sim_device_config_dev_name_show(struct config_item *item,
658 char *page)
659{
660 struct gpio_sim_device *dev = to_gpio_sim_device(item);
661 struct platform_device *pdev;
662 int ret;
663
664 mutex_lock(&dev->lock);
665 pdev = dev->pdev;
666 if (pdev)
667 ret = sprintf(page, "%s\n", dev_name(&pdev->dev));
668 else
669 ret = sprintf(page, "gpio-sim.%d\n", dev->id);
670 mutex_unlock(&dev->lock);
671
672 return ret;
673}
674
675CONFIGFS_ATTR_RO(gpio_sim_device_config_, dev_name);
676
677static ssize_t
678gpio_sim_device_config_live_show(struct config_item *item, char *page)
679{
680 struct gpio_sim_device *dev = to_gpio_sim_device(item);
681 bool live;
682
683 mutex_lock(&dev->lock);
684 live = gpio_sim_device_is_live_unlocked(dev);
685 mutex_unlock(&dev->lock);
686
687 return sprintf(page, "%c\n", live ? '1' : '0');
688}
689
690static char **gpio_sim_make_line_names(struct gpio_sim_bank *bank,
691 unsigned int *line_names_size)
692{
693 unsigned int max_offset = 0;
694 bool has_line_names = false;
695 struct gpio_sim_line *line;
696 char **line_names;
697
698 list_for_each_entry(line, &bank->line_list, siblings) {
699 if (line->name) {
700 if (line->offset > max_offset)
701 max_offset = line->offset;
702
703 /*
704 * max_offset can stay at 0 so it's not an indicator
705 * of whether line names were configured at all.
706 */
707 has_line_names = true;
708 }
709 }
710
711 if (!has_line_names)
712 /*
713 * This is not an error - NULL means, there are no line
714 * names configured.
715 */
716 return NULL;
717
718 *line_names_size = max_offset + 1;
719
720 line_names = kcalloc(*line_names_size, sizeof(*line_names), GFP_KERNEL);
721 if (!line_names)
722 return ERR_PTR(-ENOMEM);
723
724 list_for_each_entry(line, &bank->line_list, siblings)
725 line_names[line->offset] = line->name;
726
727 return line_names;
728}
729
730static void gpio_sim_remove_hogs(struct gpio_sim_device *dev)
731{
732 struct gpiod_hog *hog;
733
734 if (!dev->hogs)
735 return;
736
737 gpiod_remove_hogs(dev->hogs);
738
739 for (hog = dev->hogs; hog->chip_label; hog++) {
740 kfree(hog->chip_label);
741 kfree(hog->line_name);
742 }
743
744 kfree(dev->hogs);
745 dev->hogs = NULL;
746}
747
748static int gpio_sim_add_hogs(struct gpio_sim_device *dev)
749{
750 unsigned int num_hogs = 0, idx = 0;
751 struct gpio_sim_bank *bank;
752 struct gpio_sim_line *line;
753 struct gpiod_hog *hog;
754
755 list_for_each_entry(bank, &dev->bank_list, siblings) {
756 list_for_each_entry(line, &bank->line_list, siblings) {
757 if (line->hog)
758 num_hogs++;
759 }
760 }
761
762 if (!num_hogs)
763 return 0;
764
765 /* Allocate one more for the sentinel. */
766 dev->hogs = kcalloc(num_hogs + 1, sizeof(*dev->hogs), GFP_KERNEL);
767 if (!dev->hogs)
768 return -ENOMEM;
769
770 list_for_each_entry(bank, &dev->bank_list, siblings) {
771 list_for_each_entry(line, &bank->line_list, siblings) {
772 if (!line->hog)
773 continue;
774
775 hog = &dev->hogs[idx++];
776
777 /*
778 * We need to make this string manually because at this
779 * point the device doesn't exist yet and so dev_name()
780 * is not available.
781 */
782 if (gpio_sim_bank_has_label(bank))
783 hog->chip_label = kstrdup(bank->label,
784 GFP_KERNEL);
785 else
786 hog->chip_label = kasprintf(GFP_KERNEL,
787 "gpio-sim.%u-%s",
788 dev->id,
789 fwnode_get_name(
790 bank->swnode));
791 if (!hog->chip_label) {
792 gpio_sim_remove_hogs(dev);
793 return -ENOMEM;
794 }
795
796 /*
797 * We need to duplicate this because the hog config
798 * item can be removed at any time (and we can't block
799 * it) and gpiolib doesn't make a deep copy of the hog
800 * data.
801 */
802 if (line->hog->name) {
803 hog->line_name = kstrdup(line->hog->name,
804 GFP_KERNEL);
805 if (!hog->line_name) {
806 gpio_sim_remove_hogs(dev);
807 return -ENOMEM;
808 }
809 }
810
811 hog->chip_hwnum = line->offset;
812 hog->dflags = line->hog->dir;
813 }
814 }
815
816 gpiod_add_hogs(dev->hogs);
817
818 return 0;
819}
820
821static struct fwnode_handle *
822gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank,
823 struct fwnode_handle *parent)
824{
825 struct property_entry properties[GPIO_SIM_PROP_MAX];
826 unsigned int prop_idx = 0, line_names_size = 0;
827 struct fwnode_handle *swnode;
828 char **line_names;
829
830 memset(properties, 0, sizeof(properties));
831
832 properties[prop_idx++] = PROPERTY_ENTRY_U32("ngpios", bank->num_lines);
833
834 if (gpio_sim_bank_has_label(bank))
835 properties[prop_idx++] = PROPERTY_ENTRY_STRING("gpio-sim,label",
836 bank->label);
837
838 line_names = gpio_sim_make_line_names(bank, &line_names_size);
839 if (IS_ERR(line_names))
840 return ERR_CAST(line_names);
841
842 if (line_names)
843 properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
844 "gpio-line-names",
845 line_names, line_names_size);
846
847 swnode = fwnode_create_software_node(properties, parent);
848 kfree(line_names);
849 return swnode;
850}
851
852static void gpio_sim_remove_swnode_recursive(struct fwnode_handle *swnode)
853{
854 struct fwnode_handle *child;
855
856 fwnode_for_each_child_node(swnode, child)
857 fwnode_remove_software_node(child);
858
859 fwnode_remove_software_node(swnode);
860}
861
862static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev)
863{
864 struct gpio_sim_bank *this, *pos;
865
866 list_for_each_entry(this, &dev->bank_list, siblings) {
867 list_for_each_entry(pos, &dev->bank_list, siblings) {
868 if (this == pos || (!this->label || !pos->label))
869 continue;
870
871 if (strcmp(this->label, pos->label) == 0)
872 return true;
873 }
874 }
875
876 return false;
877}
878
879static int gpio_sim_device_activate_unlocked(struct gpio_sim_device *dev)
880{
881 struct platform_device_info pdevinfo;
882 struct fwnode_handle *swnode;
883 struct platform_device *pdev;
884 struct gpio_sim_bank *bank;
885 int ret;
886
887 if (list_empty(&dev->bank_list))
888 return -ENODATA;
889
890 /*
891 * Non-unique GPIO device labels are a corner-case we don't support
892 * as it would interfere with machine hogging mechanism and has little
893 * use in real life.
894 */
895 if (gpio_sim_bank_labels_non_unique(dev))
896 return -EINVAL;
897
898 memset(&pdevinfo, 0, sizeof(pdevinfo));
899
900 swnode = fwnode_create_software_node(NULL, NULL);
901 if (IS_ERR(swnode))
902 return PTR_ERR(swnode);
903
904 list_for_each_entry(bank, &dev->bank_list, siblings) {
905 bank->swnode = gpio_sim_make_bank_swnode(bank, swnode);
906 if (IS_ERR(bank->swnode)) {
907 ret = PTR_ERR(bank->swnode);
908 gpio_sim_remove_swnode_recursive(swnode);
909 return ret;
910 }
911 }
912
913 ret = gpio_sim_add_hogs(dev);
914 if (ret) {
915 gpio_sim_remove_swnode_recursive(swnode);
916 return ret;
917 }
918
919 pdevinfo.name = "gpio-sim";
920 pdevinfo.fwnode = swnode;
921 pdevinfo.id = dev->id;
922
923 reinit_completion(&dev->probe_completion);
924 dev->driver_bound = false;
925 bus_register_notifier(&platform_bus_type, &dev->bus_notifier);
926
927 pdev = platform_device_register_full(&pdevinfo);
928 if (IS_ERR(pdev)) {
929 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier);
930 gpio_sim_remove_hogs(dev);
931 gpio_sim_remove_swnode_recursive(swnode);
932 return PTR_ERR(pdev);
933 }
934
935 wait_for_completion(&dev->probe_completion);
936 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier);
937
938 if (!dev->driver_bound) {
939 /* Probe failed, check kernel log. */
940 platform_device_unregister(pdev);
941 gpio_sim_remove_hogs(dev);
942 gpio_sim_remove_swnode_recursive(swnode);
943 return -ENXIO;
944 }
945
946 dev->pdev = pdev;
947
948 return 0;
949}
950
951static void gpio_sim_device_deactivate_unlocked(struct gpio_sim_device *dev)
952{
953 struct fwnode_handle *swnode;
954
955 swnode = dev_fwnode(&dev->pdev->dev);
956 platform_device_unregister(dev->pdev);
957 gpio_sim_remove_swnode_recursive(swnode);
958 dev->pdev = NULL;
959 gpio_sim_remove_hogs(dev);
960}
961
962static ssize_t
963gpio_sim_device_config_live_store(struct config_item *item,
964 const char *page, size_t count)
965{
966 struct gpio_sim_device *dev = to_gpio_sim_device(item);
967 bool live;
968 int ret;
969
970 ret = kstrtobool(page, &live);
971 if (ret)
972 return ret;
973
974 mutex_lock(&dev->lock);
975
976 if ((!live && !gpio_sim_device_is_live_unlocked(dev)) ||
977 (live && gpio_sim_device_is_live_unlocked(dev)))
978 ret = -EPERM;
979 else if (live)
980 ret = gpio_sim_device_activate_unlocked(dev);
981 else
982 gpio_sim_device_deactivate_unlocked(dev);
983
984 mutex_unlock(&dev->lock);
985
986 return ret ?: count;
987}
988
989CONFIGFS_ATTR(gpio_sim_device_config_, live);
990
991static struct configfs_attribute *gpio_sim_device_config_attrs[] = {
992 &gpio_sim_device_config_attr_dev_name,
993 &gpio_sim_device_config_attr_live,
994 NULL
995};
996
997struct gpio_sim_chip_name_ctx {
998 struct fwnode_handle *swnode;
999 char *page;
1000};
1001
1002static int gpio_sim_emit_chip_name(struct device *dev, void *data)
1003{
1004 struct gpio_sim_chip_name_ctx *ctx = data;
1005
1006 /* This would be the sysfs device exported in /sys/class/gpio. */
1007 if (dev->class)
1008 return 0;
1009
1010 if (device_match_fwnode(dev, ctx->swnode))
1011 return sprintf(ctx->page, "%s\n", dev_name(dev));
1012
1013 return 0;
1014}
1015
1016static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item,
1017 char *page)
1018{
1019 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1020 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1021 struct gpio_sim_chip_name_ctx ctx = { bank->swnode, page };
1022 int ret;
1023
1024 mutex_lock(&dev->lock);
1025 if (gpio_sim_device_is_live_unlocked(dev))
1026 ret = device_for_each_child(&dev->pdev->dev, &ctx,
1027 gpio_sim_emit_chip_name);
1028 else
1029 ret = sprintf(page, "none\n");
1030 mutex_unlock(&dev->lock);
1031
1032 return ret;
1033}
1034
1035CONFIGFS_ATTR_RO(gpio_sim_bank_config_, chip_name);
1036
1037static ssize_t
1038gpio_sim_bank_config_label_show(struct config_item *item, char *page)
1039{
1040 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1041 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1042 int ret;
1043
1044 mutex_lock(&dev->lock);
1045 ret = sprintf(page, "%s\n", bank->label ?: "");
1046 mutex_unlock(&dev->lock);
1047
1048 return ret;
1049}
1050
1051static ssize_t gpio_sim_bank_config_label_store(struct config_item *item,
1052 const char *page, size_t count)
1053{
1054 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1055 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1056 char *trimmed;
1057
1058 mutex_lock(&dev->lock);
1059
1060 if (gpio_sim_device_is_live_unlocked(dev)) {
1061 mutex_unlock(&dev->lock);
1062 return -EBUSY;
1063 }
1064
1065 trimmed = gpio_sim_strdup_trimmed(page, count);
1066 if (!trimmed) {
1067 mutex_unlock(&dev->lock);
1068 return -ENOMEM;
1069 }
1070
1071 kfree(bank->label);
1072 bank->label = trimmed;
1073
1074 mutex_unlock(&dev->lock);
1075 return count;
1076}
1077
1078CONFIGFS_ATTR(gpio_sim_bank_config_, label);
1079
1080static ssize_t
1081gpio_sim_bank_config_num_lines_show(struct config_item *item, char *page)
1082{
1083 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1084 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1085 int ret;
1086
1087 mutex_lock(&dev->lock);
1088 ret = sprintf(page, "%u\n", bank->num_lines);
1089 mutex_unlock(&dev->lock);
1090
1091 return ret;
1092}
1093
1094static ssize_t
1095gpio_sim_bank_config_num_lines_store(struct config_item *item,
1096 const char *page, size_t count)
1097{
1098 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1099 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1100 unsigned int num_lines;
1101 int ret;
1102
1103 ret = kstrtouint(page, 0, &num_lines);
1104 if (ret)
1105 return ret;
1106
1107 if (num_lines == 0)
1108 return -EINVAL;
1109
1110 mutex_lock(&dev->lock);
1111
1112 if (gpio_sim_device_is_live_unlocked(dev)) {
1113 mutex_unlock(&dev->lock);
1114 return -EBUSY;
1115 }
1116
1117 bank->num_lines = num_lines;
1118
1119 mutex_unlock(&dev->lock);
1120 return count;
1121}
1122
1123CONFIGFS_ATTR(gpio_sim_bank_config_, num_lines);
1124
1125static struct configfs_attribute *gpio_sim_bank_config_attrs[] = {
1126 &gpio_sim_bank_config_attr_chip_name,
1127 &gpio_sim_bank_config_attr_label,
1128 &gpio_sim_bank_config_attr_num_lines,
1129 NULL
1130};
1131
1132static ssize_t
1133gpio_sim_line_config_name_show(struct config_item *item, char *page)
1134{
1135 struct gpio_sim_line *line = to_gpio_sim_line(item);
1136 struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
1137 int ret;
1138
1139 mutex_lock(&dev->lock);
1140 ret = sprintf(page, "%s\n", line->name ?: "");
1141 mutex_unlock(&dev->lock);
1142
1143 return ret;
1144}
1145
1146static ssize_t gpio_sim_line_config_name_store(struct config_item *item,
1147 const char *page, size_t count)
1148{
1149 struct gpio_sim_line *line = to_gpio_sim_line(item);
1150 struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
1151 char *trimmed;
1152
1153 mutex_lock(&dev->lock);
1154
1155 if (gpio_sim_device_is_live_unlocked(dev)) {
1156 mutex_unlock(&dev->lock);
1157 return -EBUSY;
1158 }
1159
1160 trimmed = gpio_sim_strdup_trimmed(page, count);
1161 if (!trimmed) {
1162 mutex_unlock(&dev->lock);
1163 return -ENOMEM;
1164 }
1165
1166 kfree(line->name);
1167 line->name = trimmed;
1168
1169 mutex_unlock(&dev->lock);
1170
1171 return count;
1172}
1173
1174CONFIGFS_ATTR(gpio_sim_line_config_, name);
1175
1176static struct configfs_attribute *gpio_sim_line_config_attrs[] = {
1177 &gpio_sim_line_config_attr_name,
1178 NULL
1179};
1180
1181static ssize_t gpio_sim_hog_config_name_show(struct config_item *item,
1182 char *page)
1183{
1184 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1185 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1186 int ret;
1187
1188 mutex_lock(&dev->lock);
1189 ret = sprintf(page, "%s\n", hog->name ?: "");
1190 mutex_unlock(&dev->lock);
1191
1192 return ret;
1193}
1194
1195static ssize_t gpio_sim_hog_config_name_store(struct config_item *item,
1196 const char *page, size_t count)
1197{
1198 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1199 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1200 char *trimmed;
1201
1202 mutex_lock(&dev->lock);
1203
1204 if (gpio_sim_device_is_live_unlocked(dev)) {
1205 mutex_unlock(&dev->lock);
1206 return -EBUSY;
1207 }
1208
1209 trimmed = gpio_sim_strdup_trimmed(page, count);
1210 if (!trimmed) {
1211 mutex_unlock(&dev->lock);
1212 return -ENOMEM;
1213 }
1214
1215 kfree(hog->name);
1216 hog->name = trimmed;
1217
1218 mutex_unlock(&dev->lock);
1219
1220 return count;
1221}
1222
1223CONFIGFS_ATTR(gpio_sim_hog_config_, name);
1224
1225static ssize_t gpio_sim_hog_config_direction_show(struct config_item *item,
1226 char *page)
1227{
1228 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1229 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1230 char *repr;
1231 int dir;
1232
1233 mutex_lock(&dev->lock);
1234 dir = hog->dir;
1235 mutex_unlock(&dev->lock);
1236
1237 switch (dir) {
1238 case GPIOD_IN:
1239 repr = "input";
1240 break;
1241 case GPIOD_OUT_HIGH:
1242 repr = "output-high";
1243 break;
1244 case GPIOD_OUT_LOW:
1245 repr = "output-low";
1246 break;
1247 default:
1248 /* This would be a programmer bug. */
1249 WARN(1, "Unexpected hog direction value: %d", dir);
1250 return -EINVAL;
1251 }
1252
1253 return sprintf(page, "%s\n", repr);
1254}
1255
1256static ssize_t
1257gpio_sim_hog_config_direction_store(struct config_item *item,
1258 const char *page, size_t count)
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 char *trimmed;
1263 int dir;
1264
1265 mutex_lock(&dev->lock);
1266
1267 if (gpio_sim_device_is_live_unlocked(dev)) {
1268 mutex_unlock(&dev->lock);
1269 return -EBUSY;
1270 }
1271
1272 trimmed = gpio_sim_strdup_trimmed(page, count);
1273 if (!trimmed) {
1274 mutex_unlock(&dev->lock);
1275 return -ENOMEM;
1276 }
1277
1278 if (strcmp(trimmed, "input") == 0)
1279 dir = GPIOD_IN;
1280 else if (strcmp(trimmed, "output-high") == 0)
1281 dir = GPIOD_OUT_HIGH;
1282 else if (strcmp(trimmed, "output-low") == 0)
1283 dir = GPIOD_OUT_LOW;
1284 else
1285 dir = -EINVAL;
1286
1287 kfree(trimmed);
1288
1289 if (dir < 0) {
1290 mutex_unlock(&dev->lock);
1291 return dir;
1292 }
1293
1294 hog->dir = dir;
1295
1296 mutex_unlock(&dev->lock);
1297
1298 return count;
1299}
1300
1301CONFIGFS_ATTR(gpio_sim_hog_config_, direction);
1302
1303static struct configfs_attribute *gpio_sim_hog_config_attrs[] = {
1304 &gpio_sim_hog_config_attr_name,
1305 &gpio_sim_hog_config_attr_direction,
1306 NULL
1307};
1308
1309static void gpio_sim_hog_config_item_release(struct config_item *item)
1310{
1311 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1312 struct gpio_sim_line *line = hog->parent;
1313 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1314
1315 mutex_lock(&dev->lock);
1316 line->hog = NULL;
1317 mutex_unlock(&dev->lock);
1318
1319 kfree(hog->name);
1320 kfree(hog);
1321}
1322
1323static struct configfs_item_operations gpio_sim_hog_config_item_ops = {
1324 .release = gpio_sim_hog_config_item_release,
1325};
1326
1327static const struct config_item_type gpio_sim_hog_config_type = {
1328 .ct_item_ops = &gpio_sim_hog_config_item_ops,
1329 .ct_attrs = gpio_sim_hog_config_attrs,
1330 .ct_owner = THIS_MODULE,
1331};
1332
1333static struct config_item *
1334gpio_sim_line_config_make_hog_item(struct config_group *group, const char *name)
1335{
1336 struct gpio_sim_line *line = to_gpio_sim_line(&group->cg_item);
1337 struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
1338 struct gpio_sim_hog *hog;
1339
1340 if (strcmp(name, "hog") != 0)
1341 return ERR_PTR(-EINVAL);
1342
1343 mutex_lock(&dev->lock);
1344
1345 hog = kzalloc(sizeof(*hog), GFP_KERNEL);
1346 if (!hog) {
1347 mutex_unlock(&dev->lock);
1348 return ERR_PTR(-ENOMEM);
1349 }
1350
1351 config_item_init_type_name(&hog->item, name,
1352 &gpio_sim_hog_config_type);
1353
1354 hog->dir = GPIOD_IN;
1355 hog->name = NULL;
1356 hog->parent = line;
1357 line->hog = hog;
1358
1359 mutex_unlock(&dev->lock);
1360
1361 return &hog->item;
1362}
1363
1364static void gpio_sim_line_config_group_release(struct config_item *item)
1365{
1366 struct gpio_sim_line *line = to_gpio_sim_line(item);
1367 struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
1368
1369 mutex_lock(&dev->lock);
1370 list_del(&line->siblings);
1371 mutex_unlock(&dev->lock);
1372
1373 kfree(line->name);
1374 kfree(line);
1375}
1376
1377static struct configfs_item_operations gpio_sim_line_config_item_ops = {
1378 .release = gpio_sim_line_config_group_release,
1379};
1380
1381static struct configfs_group_operations gpio_sim_line_config_group_ops = {
1382 .make_item = gpio_sim_line_config_make_hog_item,
1383};
1384
1385static const struct config_item_type gpio_sim_line_config_type = {
1386 .ct_item_ops = &gpio_sim_line_config_item_ops,
1387 .ct_group_ops = &gpio_sim_line_config_group_ops,
1388 .ct_attrs = gpio_sim_line_config_attrs,
1389 .ct_owner = THIS_MODULE,
1390};
1391
1392static struct config_group *
1393gpio_sim_bank_config_make_line_group(struct config_group *group,
1394 const char *name)
1395{
1396 struct gpio_sim_bank *bank = to_gpio_sim_bank(&group->cg_item);
1397 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1398 struct gpio_sim_line *line;
1399 unsigned int offset;
1400 int ret, nchar;
1401
1402 ret = sscanf(name, "line%u%n", &offset, &nchar);
1403 if (ret != 1 || nchar != strlen(name))
1404 return ERR_PTR(-EINVAL);
1405
1406 mutex_lock(&dev->lock);
1407
1408 if (gpio_sim_device_is_live_unlocked(dev)) {
1409 mutex_unlock(&dev->lock);
1410 return ERR_PTR(-EBUSY);
1411 }
1412
1413 line = kzalloc(sizeof(*line), GFP_KERNEL);
1414 if (!line) {
1415 mutex_unlock(&dev->lock);
1416 return ERR_PTR(-ENOMEM);
1417 }
1418
1419 config_group_init_type_name(&line->group, name,
1420 &gpio_sim_line_config_type);
1421
1422 line->parent = bank;
1423 line->offset = offset;
1424 list_add_tail(&line->siblings, &bank->line_list);
1425
1426 mutex_unlock(&dev->lock);
1427
1428 return &line->group;
1429}
1430
1431static void gpio_sim_bank_config_group_release(struct config_item *item)
1432{
1433 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1434 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1435
1436 mutex_lock(&dev->lock);
1437 list_del(&bank->siblings);
1438 mutex_unlock(&dev->lock);
1439
1440 kfree(bank->label);
1441 kfree(bank);
1442}
1443
1444static struct configfs_item_operations gpio_sim_bank_config_item_ops = {
1445 .release = gpio_sim_bank_config_group_release,
1446};
1447
1448static struct configfs_group_operations gpio_sim_bank_config_group_ops = {
1449 .make_group = gpio_sim_bank_config_make_line_group,
1450};
1451
1452static const struct config_item_type gpio_sim_bank_config_group_type = {
1453 .ct_item_ops = &gpio_sim_bank_config_item_ops,
1454 .ct_group_ops = &gpio_sim_bank_config_group_ops,
1455 .ct_attrs = gpio_sim_bank_config_attrs,
1456 .ct_owner = THIS_MODULE,
1457};
1458
1459static struct config_group *
1460gpio_sim_device_config_make_bank_group(struct config_group *group,
1461 const char *name)
1462{
1463 struct gpio_sim_device *dev = to_gpio_sim_device(&group->cg_item);
1464 struct gpio_sim_bank *bank;
1465
1466 mutex_lock(&dev->lock);
1467
1468 if (gpio_sim_device_is_live_unlocked(dev)) {
1469 mutex_unlock(&dev->lock);
1470 return ERR_PTR(-EBUSY);
1471 }
1472
1473 bank = kzalloc(sizeof(*bank), GFP_KERNEL);
1474 if (!bank) {
1475 mutex_unlock(&dev->lock);
1476 return ERR_PTR(-ENOMEM);
1477 }
1478
1479 config_group_init_type_name(&bank->group, name,
1480 &gpio_sim_bank_config_group_type);
1481 bank->num_lines = 1;
1482 bank->parent = dev;
1483 INIT_LIST_HEAD(&bank->line_list);
1484 list_add_tail(&bank->siblings, &dev->bank_list);
1485
1486 mutex_unlock(&dev->lock);
1487
1488 return &bank->group;
1489}
1490
1491static void gpio_sim_device_config_group_release(struct config_item *item)
1492{
1493 struct gpio_sim_device *dev = to_gpio_sim_device(item);
1494
1495 mutex_lock(&dev->lock);
1496 if (gpio_sim_device_is_live_unlocked(dev))
1497 gpio_sim_device_deactivate_unlocked(dev);
1498 mutex_unlock(&dev->lock);
1499
1500 mutex_destroy(&dev->lock);
1501 ida_free(&gpio_sim_ida, dev->id);
1502 kfree(dev);
1503}
1504
1505static struct configfs_item_operations gpio_sim_device_config_item_ops = {
1506 .release = gpio_sim_device_config_group_release,
1507};
1508
1509static struct configfs_group_operations gpio_sim_device_config_group_ops = {
1510 .make_group = gpio_sim_device_config_make_bank_group,
1511};
1512
1513static const struct config_item_type gpio_sim_device_config_group_type = {
1514 .ct_item_ops = &gpio_sim_device_config_item_ops,
1515 .ct_group_ops = &gpio_sim_device_config_group_ops,
1516 .ct_attrs = gpio_sim_device_config_attrs,
1517 .ct_owner = THIS_MODULE,
1518};
1519
1520static struct config_group *
1521gpio_sim_config_make_device_group(struct config_group *group, const char *name)
1522{
1523 struct gpio_sim_device *dev;
1524 int id;
1525
1526 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1527 if (!dev)
1528 return ERR_PTR(-ENOMEM);
1529
1530 id = ida_alloc(&gpio_sim_ida, GFP_KERNEL);
1531 if (id < 0) {
1532 kfree(dev);
1533 return ERR_PTR(id);
1534 }
1535
1536 config_group_init_type_name(&dev->group, name,
1537 &gpio_sim_device_config_group_type);
1538 dev->id = id;
1539 mutex_init(&dev->lock);
1540 INIT_LIST_HEAD(&dev->bank_list);
1541
1542 dev->bus_notifier.notifier_call = gpio_sim_bus_notifier_call;
1543 init_completion(&dev->probe_completion);
1544
1545 return &dev->group;
1546}
1547
1548static struct configfs_group_operations gpio_sim_config_group_ops = {
1549 .make_group = gpio_sim_config_make_device_group,
1550};
1551
1552static const struct config_item_type gpio_sim_config_type = {
1553 .ct_group_ops = &gpio_sim_config_group_ops,
1554 .ct_owner = THIS_MODULE,
1555};
1556
1557static struct configfs_subsystem gpio_sim_config_subsys = {
1558 .su_group = {
1559 .cg_item = {
1560 .ci_namebuf = "gpio-sim",
1561 .ci_type = &gpio_sim_config_type,
1562 },
1563 },
1564};
1565
1566static int __init gpio_sim_init(void)
1567{
1568 int ret;
1569
1570 ret = platform_driver_register(&gpio_sim_driver);
1571 if (ret) {
1572 pr_err("Error %d while registering the platform driver\n", ret);
1573 return ret;
1574 }
1575
1576 config_group_init(&gpio_sim_config_subsys.su_group);
1577 mutex_init(&gpio_sim_config_subsys.su_mutex);
1578 ret = configfs_register_subsystem(&gpio_sim_config_subsys);
1579 if (ret) {
1580 pr_err("Error %d while registering the configfs subsystem %s\n",
1581 ret, gpio_sim_config_subsys.su_group.cg_item.ci_namebuf);
1582 mutex_destroy(&gpio_sim_config_subsys.su_mutex);
1583 platform_driver_unregister(&gpio_sim_driver);
1584 return ret;
1585 }
1586
1587 return 0;
1588}
1589module_init(gpio_sim_init);
1590
1591static void __exit gpio_sim_exit(void)
1592{
1593 configfs_unregister_subsystem(&gpio_sim_config_subsys);
1594 mutex_destroy(&gpio_sim_config_subsys.su_mutex);
1595 platform_driver_unregister(&gpio_sim_driver);
1596}
1597module_exit(gpio_sim_exit);
1598
1599MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl");
1600MODULE_DESCRIPTION("GPIO Simulator Module");
1601MODULE_LICENSE("GPL");