Loading...
Note: File does not exist in v4.6.
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/cleanup.h>
12#include <linux/completion.h>
13#include <linux/configfs.h>
14#include <linux/device.h>
15#include <linux/err.h>
16#include <linux/gpio/consumer.h>
17#include <linux/gpio/driver.h>
18#include <linux/gpio/machine.h>
19#include <linux/idr.h>
20#include <linux/interrupt.h>
21#include <linux/irq.h>
22#include <linux/irq_sim.h>
23#include <linux/kernel.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 void gpio_sim_dbg_show(struct seq_file *seq, struct gpio_chip *gc)
231{
232 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
233 const char *label;
234 int i;
235
236 guard(mutex)(&chip->lock);
237
238 for_each_hwgpio(gc, i, label)
239 seq_printf(seq, " gpio-%-3d (%s) %s,%s\n",
240 gc->base + i,
241 label ?: "<unused>",
242 test_bit(i, chip->direction_map) ? "input" :
243 test_bit(i, chip->value_map) ? "output-high" :
244 "output-low",
245 test_bit(i, chip->pull_map) ? "pull-up" :
246 "pull-down");
247}
248
249static ssize_t gpio_sim_sysfs_val_show(struct device *dev,
250 struct device_attribute *attr, char *buf)
251{
252 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
253 struct gpio_sim_chip *chip = dev_get_drvdata(dev);
254 int val;
255
256 scoped_guard(mutex, &chip->lock)
257 val = !!test_bit(line_attr->offset, chip->value_map);
258
259 return sysfs_emit(buf, "%d\n", val);
260}
261
262static ssize_t gpio_sim_sysfs_val_store(struct device *dev,
263 struct device_attribute *attr,
264 const char *buf, size_t count)
265{
266 /*
267 * Not assigning this function will result in write() returning -EIO
268 * which is confusing. Return -EPERM explicitly.
269 */
270 return -EPERM;
271}
272
273static const char *const gpio_sim_sysfs_pull_strings[] = {
274 [0] = "pull-down",
275 [1] = "pull-up",
276};
277
278static ssize_t gpio_sim_sysfs_pull_show(struct device *dev,
279 struct device_attribute *attr,
280 char *buf)
281{
282 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
283 struct gpio_sim_chip *chip = dev_get_drvdata(dev);
284 int pull;
285
286 scoped_guard(mutex, &chip->lock)
287 pull = !!test_bit(line_attr->offset, chip->pull_map);
288
289 return sysfs_emit(buf, "%s\n", gpio_sim_sysfs_pull_strings[pull]);
290}
291
292static ssize_t gpio_sim_sysfs_pull_store(struct device *dev,
293 struct device_attribute *attr,
294 const char *buf, size_t len)
295{
296 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
297 struct gpio_sim_chip *chip = dev_get_drvdata(dev);
298 int ret, pull;
299
300 pull = sysfs_match_string(gpio_sim_sysfs_pull_strings, buf);
301 if (pull < 0)
302 return pull;
303
304 ret = gpio_sim_apply_pull(chip, line_attr->offset, pull);
305 if (ret)
306 return ret;
307
308 return len;
309}
310
311static void gpio_sim_mutex_destroy(void *data)
312{
313 struct mutex *lock = data;
314
315 mutex_destroy(lock);
316}
317
318static void gpio_sim_put_device(void *data)
319{
320 struct device *dev = data;
321
322 put_device(dev);
323}
324
325static void gpio_sim_dispose_mappings(void *data)
326{
327 struct gpio_sim_chip *chip = data;
328 unsigned int i;
329
330 for (i = 0; i < chip->gc.ngpio; i++)
331 irq_dispose_mapping(irq_find_mapping(chip->irq_sim, i));
332}
333
334static void gpio_sim_sysfs_remove(void *data)
335{
336 struct gpio_sim_chip *chip = data;
337
338 sysfs_remove_groups(&chip->dev->kobj, chip->attr_groups);
339}
340
341static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip)
342{
343 struct device_attribute *val_dev_attr, *pull_dev_attr;
344 struct gpio_sim_attribute *val_attr, *pull_attr;
345 unsigned int num_lines = chip->gc.ngpio;
346 struct device *dev = chip->gc.parent;
347 struct attribute_group *attr_group;
348 struct attribute **attrs;
349 int i, ret;
350
351 chip->attr_groups = devm_kcalloc(dev, sizeof(*chip->attr_groups),
352 num_lines + 1, GFP_KERNEL);
353 if (!chip->attr_groups)
354 return -ENOMEM;
355
356 for (i = 0; i < num_lines; i++) {
357 attr_group = devm_kzalloc(dev, sizeof(*attr_group), GFP_KERNEL);
358 attrs = devm_kcalloc(dev, GPIO_SIM_NUM_ATTRS, sizeof(*attrs),
359 GFP_KERNEL);
360 val_attr = devm_kzalloc(dev, sizeof(*val_attr), GFP_KERNEL);
361 pull_attr = devm_kzalloc(dev, sizeof(*pull_attr), GFP_KERNEL);
362 if (!attr_group || !attrs || !val_attr || !pull_attr)
363 return -ENOMEM;
364
365 attr_group->name = devm_kasprintf(dev, GFP_KERNEL,
366 "sim_gpio%u", i);
367 if (!attr_group->name)
368 return -ENOMEM;
369
370 val_attr->offset = pull_attr->offset = i;
371
372 val_dev_attr = &val_attr->dev_attr;
373 pull_dev_attr = &pull_attr->dev_attr;
374
375 sysfs_attr_init(&val_dev_attr->attr);
376 sysfs_attr_init(&pull_dev_attr->attr);
377
378 val_dev_attr->attr.name = "value";
379 pull_dev_attr->attr.name = "pull";
380
381 val_dev_attr->attr.mode = pull_dev_attr->attr.mode = 0644;
382
383 val_dev_attr->show = gpio_sim_sysfs_val_show;
384 val_dev_attr->store = gpio_sim_sysfs_val_store;
385 pull_dev_attr->show = gpio_sim_sysfs_pull_show;
386 pull_dev_attr->store = gpio_sim_sysfs_pull_store;
387
388 attrs[0] = &val_dev_attr->attr;
389 attrs[1] = &pull_dev_attr->attr;
390
391 attr_group->attrs = attrs;
392 chip->attr_groups[i] = attr_group;
393 }
394
395 ret = sysfs_create_groups(&chip->dev->kobj, chip->attr_groups);
396 if (ret)
397 return ret;
398
399 return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip);
400}
401
402static int gpio_sim_dev_match_fwnode(struct device *dev, void *data)
403{
404 return device_match_fwnode(dev, data);
405}
406
407static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
408{
409 struct gpio_sim_chip *chip;
410 struct gpio_chip *gc;
411 const char *label;
412 u32 num_lines;
413 int ret;
414
415 ret = fwnode_property_read_u32(swnode, "ngpios", &num_lines);
416 if (ret)
417 return ret;
418
419 if (num_lines > GPIO_SIM_NGPIO_MAX)
420 return -ERANGE;
421
422 ret = fwnode_property_read_string(swnode, "gpio-sim,label", &label);
423 if (ret) {
424 label = devm_kasprintf(dev, GFP_KERNEL, "%s:%pfwP",
425 dev_name(dev), swnode);
426 if (!label)
427 return -ENOMEM;
428 }
429
430 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
431 if (!chip)
432 return -ENOMEM;
433
434 chip->request_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL);
435 if (!chip->request_map)
436 return -ENOMEM;
437
438 chip->direction_map = devm_bitmap_alloc(dev, num_lines, GFP_KERNEL);
439 if (!chip->direction_map)
440 return -ENOMEM;
441
442 /* Default to input mode. */
443 bitmap_fill(chip->direction_map, num_lines);
444
445 chip->value_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL);
446 if (!chip->value_map)
447 return -ENOMEM;
448
449 chip->pull_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL);
450 if (!chip->pull_map)
451 return -ENOMEM;
452
453 chip->irq_sim = devm_irq_domain_create_sim(dev, swnode, num_lines);
454 if (IS_ERR(chip->irq_sim))
455 return PTR_ERR(chip->irq_sim);
456
457 ret = devm_add_action_or_reset(dev, gpio_sim_dispose_mappings, chip);
458 if (ret)
459 return ret;
460
461 mutex_init(&chip->lock);
462 ret = devm_add_action_or_reset(dev, gpio_sim_mutex_destroy,
463 &chip->lock);
464 if (ret)
465 return ret;
466
467 gc = &chip->gc;
468 gc->base = -1;
469 gc->ngpio = num_lines;
470 gc->label = label;
471 gc->owner = THIS_MODULE;
472 gc->parent = dev;
473 gc->fwnode = swnode;
474 gc->get = gpio_sim_get;
475 gc->set = gpio_sim_set;
476 gc->get_multiple = gpio_sim_get_multiple;
477 gc->set_multiple = gpio_sim_set_multiple;
478 gc->direction_output = gpio_sim_direction_output;
479 gc->direction_input = gpio_sim_direction_input;
480 gc->get_direction = gpio_sim_get_direction;
481 gc->set_config = gpio_sim_set_config;
482 gc->to_irq = gpio_sim_to_irq;
483 gc->request = gpio_sim_request;
484 gc->free = gpio_sim_free;
485 gc->dbg_show = PTR_IF(IS_ENABLED(CONFIG_DEBUG_FS), gpio_sim_dbg_show);
486 gc->can_sleep = true;
487
488 ret = devm_gpiochip_add_data(dev, gc, chip);
489 if (ret)
490 return ret;
491
492 chip->dev = device_find_child(dev, swnode, gpio_sim_dev_match_fwnode);
493 if (!chip->dev)
494 return -ENODEV;
495
496 ret = devm_add_action_or_reset(dev, gpio_sim_put_device, chip->dev);
497 if (ret)
498 return ret;
499
500 /* Used by sysfs callbacks. */
501 dev_set_drvdata(chip->dev, chip);
502
503 return gpio_sim_setup_sysfs(chip);
504}
505
506static int gpio_sim_probe(struct platform_device *pdev)
507{
508 struct device *dev = &pdev->dev;
509 struct fwnode_handle *swnode;
510 int ret;
511
512 device_for_each_child_node(dev, swnode) {
513 ret = gpio_sim_add_bank(swnode, dev);
514 if (ret) {
515 fwnode_handle_put(swnode);
516 return ret;
517 }
518 }
519
520 return 0;
521}
522
523static const struct of_device_id gpio_sim_of_match[] = {
524 { .compatible = "gpio-simulator" },
525 { }
526};
527MODULE_DEVICE_TABLE(of, gpio_sim_of_match);
528
529static struct platform_driver gpio_sim_driver = {
530 .driver = {
531 .name = "gpio-sim",
532 .of_match_table = gpio_sim_of_match,
533 },
534 .probe = gpio_sim_probe,
535};
536
537struct gpio_sim_device {
538 struct config_group group;
539
540 /*
541 * If pdev is NULL, the device is 'pending' (waiting for configuration).
542 * Once the pointer is assigned, the device has been created and the
543 * item is 'live'.
544 */
545 struct platform_device *pdev;
546 int id;
547
548 /*
549 * Each configfs filesystem operation is protected with the subsystem
550 * mutex. Each separate attribute is protected with the buffer mutex.
551 * This structure however can be modified by callbacks of different
552 * attributes so we need another lock.
553 *
554 * We use this lock for protecting all data structures owned by this
555 * object too.
556 */
557 struct mutex lock;
558
559 /*
560 * This is used to synchronously wait for the driver's probe to complete
561 * and notify the user-space about any errors.
562 */
563 struct notifier_block bus_notifier;
564 struct completion probe_completion;
565 bool driver_bound;
566
567 struct gpiod_hog *hogs;
568
569 struct list_head bank_list;
570};
571
572/* This is called with dev->lock already taken. */
573static int gpio_sim_bus_notifier_call(struct notifier_block *nb,
574 unsigned long action, void *data)
575{
576 struct gpio_sim_device *simdev = container_of(nb,
577 struct gpio_sim_device,
578 bus_notifier);
579 struct device *dev = data;
580 char devname[32];
581
582 snprintf(devname, sizeof(devname), "gpio-sim.%u", simdev->id);
583
584 if (strcmp(dev_name(dev), devname) == 0) {
585 if (action == BUS_NOTIFY_BOUND_DRIVER)
586 simdev->driver_bound = true;
587 else if (action == BUS_NOTIFY_DRIVER_NOT_BOUND)
588 simdev->driver_bound = false;
589 else
590 return NOTIFY_DONE;
591
592 complete(&simdev->probe_completion);
593 return NOTIFY_OK;
594 }
595
596 return NOTIFY_DONE;
597}
598
599static struct gpio_sim_device *to_gpio_sim_device(struct config_item *item)
600{
601 struct config_group *group = to_config_group(item);
602
603 return container_of(group, struct gpio_sim_device, group);
604}
605
606struct gpio_sim_bank {
607 struct config_group group;
608
609 /*
610 * We could have used the ci_parent field of the config_item but
611 * configfs is stupid and calls the item's release callback after
612 * already having cleared the parent pointer even though the parent
613 * is guaranteed to survive the child...
614 *
615 * So we need to store the pointer to the parent struct here. We can
616 * dereference it anywhere we need with no checks and no locking as
617 * it's guaranteed to survive the children and protected by configfs
618 * locks.
619 *
620 * Same for other structures.
621 */
622 struct gpio_sim_device *parent;
623 struct list_head siblings;
624
625 char *label;
626 unsigned int num_lines;
627
628 struct list_head line_list;
629
630 struct fwnode_handle *swnode;
631};
632
633static struct gpio_sim_bank *to_gpio_sim_bank(struct config_item *item)
634{
635 struct config_group *group = to_config_group(item);
636
637 return container_of(group, struct gpio_sim_bank, group);
638}
639
640static bool gpio_sim_bank_has_label(struct gpio_sim_bank *bank)
641{
642 return bank->label && *bank->label;
643}
644
645static struct gpio_sim_device *
646gpio_sim_bank_get_device(struct gpio_sim_bank *bank)
647{
648 return bank->parent;
649}
650
651struct gpio_sim_hog;
652
653struct gpio_sim_line {
654 struct config_group group;
655
656 struct gpio_sim_bank *parent;
657 struct list_head siblings;
658
659 unsigned int offset;
660 char *name;
661
662 /* There can only be one hog per line. */
663 struct gpio_sim_hog *hog;
664};
665
666static struct gpio_sim_line *to_gpio_sim_line(struct config_item *item)
667{
668 struct config_group *group = to_config_group(item);
669
670 return container_of(group, struct gpio_sim_line, group);
671}
672
673static struct gpio_sim_device *
674gpio_sim_line_get_device(struct gpio_sim_line *line)
675{
676 struct gpio_sim_bank *bank = line->parent;
677
678 return gpio_sim_bank_get_device(bank);
679}
680
681struct gpio_sim_hog {
682 struct config_item item;
683 struct gpio_sim_line *parent;
684
685 char *name;
686 int dir;
687};
688
689static struct gpio_sim_hog *to_gpio_sim_hog(struct config_item *item)
690{
691 return container_of(item, struct gpio_sim_hog, item);
692}
693
694static struct gpio_sim_device *gpio_sim_hog_get_device(struct gpio_sim_hog *hog)
695{
696 struct gpio_sim_line *line = hog->parent;
697
698 return gpio_sim_line_get_device(line);
699}
700
701static bool gpio_sim_device_is_live(struct gpio_sim_device *dev)
702{
703 lockdep_assert_held(&dev->lock);
704
705 return !!dev->pdev;
706}
707
708static char *gpio_sim_strdup_trimmed(const char *str, size_t count)
709{
710 char *trimmed;
711
712 trimmed = kstrndup(skip_spaces(str), count, GFP_KERNEL);
713 if (!trimmed)
714 return NULL;
715
716 return strim(trimmed);
717}
718
719static ssize_t gpio_sim_device_config_dev_name_show(struct config_item *item,
720 char *page)
721{
722 struct gpio_sim_device *dev = to_gpio_sim_device(item);
723 struct platform_device *pdev;
724
725 guard(mutex)(&dev->lock);
726
727 pdev = dev->pdev;
728 if (pdev)
729 return sprintf(page, "%s\n", dev_name(&pdev->dev));
730
731 return sprintf(page, "gpio-sim.%d\n", dev->id);
732}
733
734CONFIGFS_ATTR_RO(gpio_sim_device_config_, dev_name);
735
736static ssize_t
737gpio_sim_device_config_live_show(struct config_item *item, char *page)
738{
739 struct gpio_sim_device *dev = to_gpio_sim_device(item);
740 bool live;
741
742 scoped_guard(mutex, &dev->lock)
743 live = gpio_sim_device_is_live(dev);
744
745 return sprintf(page, "%c\n", live ? '1' : '0');
746}
747
748static unsigned int gpio_sim_get_line_names_size(struct gpio_sim_bank *bank)
749{
750 struct gpio_sim_line *line;
751 unsigned int size = 0;
752
753 list_for_each_entry(line, &bank->line_list, siblings) {
754 if (!line->name || (line->offset >= bank->num_lines))
755 continue;
756
757 size = max(size, line->offset + 1);
758 }
759
760 return size;
761}
762
763static void
764gpio_sim_set_line_names(struct gpio_sim_bank *bank, char **line_names)
765{
766 struct gpio_sim_line *line;
767
768 list_for_each_entry(line, &bank->line_list, siblings) {
769 if (!line->name || (line->offset >= bank->num_lines))
770 continue;
771
772 line_names[line->offset] = line->name;
773 }
774}
775
776static void gpio_sim_remove_hogs(struct gpio_sim_device *dev)
777{
778 struct gpiod_hog *hog;
779
780 if (!dev->hogs)
781 return;
782
783 gpiod_remove_hogs(dev->hogs);
784
785 for (hog = dev->hogs; hog->chip_label; hog++) {
786 kfree(hog->chip_label);
787 kfree(hog->line_name);
788 }
789
790 kfree(dev->hogs);
791 dev->hogs = NULL;
792}
793
794static int gpio_sim_add_hogs(struct gpio_sim_device *dev)
795{
796 unsigned int num_hogs = 0, idx = 0;
797 struct gpio_sim_bank *bank;
798 struct gpio_sim_line *line;
799 struct gpiod_hog *hog;
800
801 list_for_each_entry(bank, &dev->bank_list, siblings) {
802 list_for_each_entry(line, &bank->line_list, siblings) {
803 if (line->offset >= bank->num_lines)
804 continue;
805
806 if (line->hog)
807 num_hogs++;
808 }
809 }
810
811 if (!num_hogs)
812 return 0;
813
814 /* Allocate one more for the sentinel. */
815 dev->hogs = kcalloc(num_hogs + 1, sizeof(*dev->hogs), GFP_KERNEL);
816 if (!dev->hogs)
817 return -ENOMEM;
818
819 list_for_each_entry(bank, &dev->bank_list, siblings) {
820 list_for_each_entry(line, &bank->line_list, siblings) {
821 if (line->offset >= bank->num_lines)
822 continue;
823
824 if (!line->hog)
825 continue;
826
827 hog = &dev->hogs[idx++];
828
829 /*
830 * We need to make this string manually because at this
831 * point the device doesn't exist yet and so dev_name()
832 * is not available.
833 */
834 if (gpio_sim_bank_has_label(bank))
835 hog->chip_label = kstrdup(bank->label,
836 GFP_KERNEL);
837 else
838 hog->chip_label = kasprintf(GFP_KERNEL,
839 "gpio-sim.%u:%pfwP",
840 dev->id,
841 bank->swnode);
842 if (!hog->chip_label) {
843 gpio_sim_remove_hogs(dev);
844 return -ENOMEM;
845 }
846
847 /*
848 * We need to duplicate this because the hog config
849 * item can be removed at any time (and we can't block
850 * it) and gpiolib doesn't make a deep copy of the hog
851 * data.
852 */
853 if (line->hog->name) {
854 hog->line_name = kstrdup(line->hog->name,
855 GFP_KERNEL);
856 if (!hog->line_name) {
857 gpio_sim_remove_hogs(dev);
858 return -ENOMEM;
859 }
860 }
861
862 hog->chip_hwnum = line->offset;
863 hog->dflags = line->hog->dir;
864 }
865 }
866
867 gpiod_add_hogs(dev->hogs);
868
869 return 0;
870}
871
872static struct fwnode_handle *
873gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank,
874 struct fwnode_handle *parent)
875{
876 struct property_entry properties[GPIO_SIM_PROP_MAX];
877 unsigned int prop_idx = 0, line_names_size;
878 char **line_names __free(kfree) = NULL;
879
880 memset(properties, 0, sizeof(properties));
881
882 properties[prop_idx++] = PROPERTY_ENTRY_U32("ngpios", bank->num_lines);
883
884 if (gpio_sim_bank_has_label(bank))
885 properties[prop_idx++] = PROPERTY_ENTRY_STRING("gpio-sim,label",
886 bank->label);
887
888 line_names_size = gpio_sim_get_line_names_size(bank);
889 if (line_names_size) {
890 line_names = kcalloc(line_names_size, sizeof(*line_names),
891 GFP_KERNEL);
892 if (!line_names)
893 return ERR_PTR(-ENOMEM);
894
895 gpio_sim_set_line_names(bank, line_names);
896
897 properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
898 "gpio-line-names",
899 line_names, line_names_size);
900 }
901
902 return fwnode_create_software_node(properties, parent);
903}
904
905static void gpio_sim_remove_swnode_recursive(struct fwnode_handle *swnode)
906{
907 struct fwnode_handle *child;
908
909 fwnode_for_each_child_node(swnode, child)
910 fwnode_remove_software_node(child);
911
912 fwnode_remove_software_node(swnode);
913}
914
915static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev)
916{
917 struct gpio_sim_bank *this, *pos;
918
919 list_for_each_entry(this, &dev->bank_list, siblings) {
920 list_for_each_entry(pos, &dev->bank_list, siblings) {
921 if (this == pos || (!this->label || !pos->label))
922 continue;
923
924 if (strcmp(this->label, pos->label) == 0)
925 return true;
926 }
927 }
928
929 return false;
930}
931
932static int gpio_sim_device_activate(struct gpio_sim_device *dev)
933{
934 struct platform_device_info pdevinfo;
935 struct fwnode_handle *swnode;
936 struct platform_device *pdev;
937 struct gpio_sim_bank *bank;
938 int ret;
939
940 lockdep_assert_held(&dev->lock);
941
942 if (list_empty(&dev->bank_list))
943 return -ENODATA;
944
945 /*
946 * Non-unique GPIO device labels are a corner-case we don't support
947 * as it would interfere with machine hogging mechanism and has little
948 * use in real life.
949 */
950 if (gpio_sim_bank_labels_non_unique(dev))
951 return -EINVAL;
952
953 memset(&pdevinfo, 0, sizeof(pdevinfo));
954
955 swnode = fwnode_create_software_node(NULL, NULL);
956 if (IS_ERR(swnode))
957 return PTR_ERR(swnode);
958
959 list_for_each_entry(bank, &dev->bank_list, siblings) {
960 bank->swnode = gpio_sim_make_bank_swnode(bank, swnode);
961 if (IS_ERR(bank->swnode)) {
962 ret = PTR_ERR(bank->swnode);
963 gpio_sim_remove_swnode_recursive(swnode);
964 return ret;
965 }
966 }
967
968 ret = gpio_sim_add_hogs(dev);
969 if (ret) {
970 gpio_sim_remove_swnode_recursive(swnode);
971 return ret;
972 }
973
974 pdevinfo.name = "gpio-sim";
975 pdevinfo.fwnode = swnode;
976 pdevinfo.id = dev->id;
977
978 reinit_completion(&dev->probe_completion);
979 dev->driver_bound = false;
980 bus_register_notifier(&platform_bus_type, &dev->bus_notifier);
981
982 pdev = platform_device_register_full(&pdevinfo);
983 if (IS_ERR(pdev)) {
984 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier);
985 gpio_sim_remove_hogs(dev);
986 gpio_sim_remove_swnode_recursive(swnode);
987 return PTR_ERR(pdev);
988 }
989
990 wait_for_completion(&dev->probe_completion);
991 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier);
992
993 if (!dev->driver_bound) {
994 /* Probe failed, check kernel log. */
995 platform_device_unregister(pdev);
996 gpio_sim_remove_hogs(dev);
997 gpio_sim_remove_swnode_recursive(swnode);
998 return -ENXIO;
999 }
1000
1001 dev->pdev = pdev;
1002
1003 return 0;
1004}
1005
1006static void gpio_sim_device_deactivate(struct gpio_sim_device *dev)
1007{
1008 struct fwnode_handle *swnode;
1009
1010 lockdep_assert_held(&dev->lock);
1011
1012 swnode = dev_fwnode(&dev->pdev->dev);
1013 platform_device_unregister(dev->pdev);
1014 gpio_sim_remove_hogs(dev);
1015 gpio_sim_remove_swnode_recursive(swnode);
1016 dev->pdev = NULL;
1017}
1018
1019static ssize_t
1020gpio_sim_device_config_live_store(struct config_item *item,
1021 const char *page, size_t count)
1022{
1023 struct gpio_sim_device *dev = to_gpio_sim_device(item);
1024 bool live;
1025 int ret;
1026
1027 ret = kstrtobool(page, &live);
1028 if (ret)
1029 return ret;
1030
1031 guard(mutex)(&dev->lock);
1032
1033 if (live == gpio_sim_device_is_live(dev))
1034 ret = -EPERM;
1035 else if (live)
1036 ret = gpio_sim_device_activate(dev);
1037 else
1038 gpio_sim_device_deactivate(dev);
1039
1040 return ret ?: count;
1041}
1042
1043CONFIGFS_ATTR(gpio_sim_device_config_, live);
1044
1045static struct configfs_attribute *gpio_sim_device_config_attrs[] = {
1046 &gpio_sim_device_config_attr_dev_name,
1047 &gpio_sim_device_config_attr_live,
1048 NULL
1049};
1050
1051struct gpio_sim_chip_name_ctx {
1052 struct fwnode_handle *swnode;
1053 char *page;
1054};
1055
1056static int gpio_sim_emit_chip_name(struct device *dev, void *data)
1057{
1058 struct gpio_sim_chip_name_ctx *ctx = data;
1059
1060 /* This would be the sysfs device exported in /sys/class/gpio. */
1061 if (dev->class)
1062 return 0;
1063
1064 if (device_match_fwnode(dev, ctx->swnode))
1065 return sprintf(ctx->page, "%s\n", dev_name(dev));
1066
1067 return 0;
1068}
1069
1070static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item,
1071 char *page)
1072{
1073 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1074 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1075 struct gpio_sim_chip_name_ctx ctx = { bank->swnode, page };
1076
1077 guard(mutex)(&dev->lock);
1078
1079 if (gpio_sim_device_is_live(dev))
1080 return device_for_each_child(&dev->pdev->dev, &ctx,
1081 gpio_sim_emit_chip_name);
1082
1083 return sprintf(page, "none\n");
1084}
1085
1086CONFIGFS_ATTR_RO(gpio_sim_bank_config_, chip_name);
1087
1088static ssize_t
1089gpio_sim_bank_config_label_show(struct config_item *item, char *page)
1090{
1091 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1092 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1093
1094 guard(mutex)(&dev->lock);
1095
1096 return sprintf(page, "%s\n", bank->label ?: "");
1097}
1098
1099static ssize_t gpio_sim_bank_config_label_store(struct config_item *item,
1100 const char *page, size_t count)
1101{
1102 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1103 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1104 char *trimmed;
1105
1106 guard(mutex)(&dev->lock);
1107
1108 if (gpio_sim_device_is_live(dev))
1109 return -EBUSY;
1110
1111 trimmed = gpio_sim_strdup_trimmed(page, count);
1112 if (!trimmed)
1113 return -ENOMEM;
1114
1115 kfree(bank->label);
1116 bank->label = trimmed;
1117
1118 return count;
1119}
1120
1121CONFIGFS_ATTR(gpio_sim_bank_config_, label);
1122
1123static ssize_t
1124gpio_sim_bank_config_num_lines_show(struct config_item *item, char *page)
1125{
1126 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1127 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1128
1129 guard(mutex)(&dev->lock);
1130
1131 return sprintf(page, "%u\n", bank->num_lines);
1132}
1133
1134static ssize_t
1135gpio_sim_bank_config_num_lines_store(struct config_item *item,
1136 const char *page, size_t count)
1137{
1138 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1139 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1140 unsigned int num_lines;
1141 int ret;
1142
1143 ret = kstrtouint(page, 0, &num_lines);
1144 if (ret)
1145 return ret;
1146
1147 if (num_lines == 0)
1148 return -EINVAL;
1149
1150 guard(mutex)(&dev->lock);
1151
1152 if (gpio_sim_device_is_live(dev))
1153 return -EBUSY;
1154
1155 bank->num_lines = num_lines;
1156
1157 return count;
1158}
1159
1160CONFIGFS_ATTR(gpio_sim_bank_config_, num_lines);
1161
1162static struct configfs_attribute *gpio_sim_bank_config_attrs[] = {
1163 &gpio_sim_bank_config_attr_chip_name,
1164 &gpio_sim_bank_config_attr_label,
1165 &gpio_sim_bank_config_attr_num_lines,
1166 NULL
1167};
1168
1169static ssize_t
1170gpio_sim_line_config_name_show(struct config_item *item, char *page)
1171{
1172 struct gpio_sim_line *line = to_gpio_sim_line(item);
1173 struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
1174
1175 guard(mutex)(&dev->lock);
1176
1177 return sprintf(page, "%s\n", line->name ?: "");
1178}
1179
1180static ssize_t gpio_sim_line_config_name_store(struct config_item *item,
1181 const char *page, size_t count)
1182{
1183 struct gpio_sim_line *line = to_gpio_sim_line(item);
1184 struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
1185 char *trimmed;
1186
1187 guard(mutex)(&dev->lock);
1188
1189 if (gpio_sim_device_is_live(dev))
1190 return -EBUSY;
1191
1192 trimmed = gpio_sim_strdup_trimmed(page, count);
1193 if (!trimmed)
1194 return -ENOMEM;
1195
1196 kfree(line->name);
1197 line->name = trimmed;
1198
1199 return count;
1200}
1201
1202CONFIGFS_ATTR(gpio_sim_line_config_, name);
1203
1204static struct configfs_attribute *gpio_sim_line_config_attrs[] = {
1205 &gpio_sim_line_config_attr_name,
1206 NULL
1207};
1208
1209static ssize_t gpio_sim_hog_config_name_show(struct config_item *item,
1210 char *page)
1211{
1212 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1213 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1214
1215 guard(mutex)(&dev->lock);
1216
1217 return sprintf(page, "%s\n", hog->name ?: "");
1218}
1219
1220static ssize_t gpio_sim_hog_config_name_store(struct config_item *item,
1221 const char *page, size_t count)
1222{
1223 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1224 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1225 char *trimmed;
1226
1227 guard(mutex)(&dev->lock);
1228
1229 if (gpio_sim_device_is_live(dev))
1230 return -EBUSY;
1231
1232 trimmed = gpio_sim_strdup_trimmed(page, count);
1233 if (!trimmed)
1234 return -ENOMEM;
1235
1236 kfree(hog->name);
1237 hog->name = trimmed;
1238
1239 return count;
1240}
1241
1242CONFIGFS_ATTR(gpio_sim_hog_config_, name);
1243
1244static ssize_t gpio_sim_hog_config_direction_show(struct config_item *item,
1245 char *page)
1246{
1247 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1248 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1249 char *repr;
1250 int dir;
1251
1252 scoped_guard(mutex, &dev->lock)
1253 dir = hog->dir;
1254
1255 switch (dir) {
1256 case GPIOD_IN:
1257 repr = "input";
1258 break;
1259 case GPIOD_OUT_HIGH:
1260 repr = "output-high";
1261 break;
1262 case GPIOD_OUT_LOW:
1263 repr = "output-low";
1264 break;
1265 default:
1266 /* This would be a programmer bug. */
1267 WARN(1, "Unexpected hog direction value: %d", dir);
1268 return -EINVAL;
1269 }
1270
1271 return sprintf(page, "%s\n", repr);
1272}
1273
1274static ssize_t
1275gpio_sim_hog_config_direction_store(struct config_item *item,
1276 const char *page, size_t count)
1277{
1278 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1279 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1280 int dir;
1281
1282 guard(mutex)(&dev->lock);
1283
1284 if (gpio_sim_device_is_live(dev))
1285 return -EBUSY;
1286
1287 if (sysfs_streq(page, "input"))
1288 dir = GPIOD_IN;
1289 else if (sysfs_streq(page, "output-high"))
1290 dir = GPIOD_OUT_HIGH;
1291 else if (sysfs_streq(page, "output-low"))
1292 dir = GPIOD_OUT_LOW;
1293 else
1294 return -EINVAL;
1295
1296 hog->dir = dir;
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 scoped_guard(mutex, &dev->lock)
1316 line->hog = NULL;
1317
1318 kfree(hog->name);
1319 kfree(hog);
1320}
1321
1322static struct configfs_item_operations gpio_sim_hog_config_item_ops = {
1323 .release = gpio_sim_hog_config_item_release,
1324};
1325
1326static const struct config_item_type gpio_sim_hog_config_type = {
1327 .ct_item_ops = &gpio_sim_hog_config_item_ops,
1328 .ct_attrs = gpio_sim_hog_config_attrs,
1329 .ct_owner = THIS_MODULE,
1330};
1331
1332static struct config_item *
1333gpio_sim_line_config_make_hog_item(struct config_group *group, const char *name)
1334{
1335 struct gpio_sim_line *line = to_gpio_sim_line(&group->cg_item);
1336 struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
1337 struct gpio_sim_hog *hog;
1338
1339 if (strcmp(name, "hog") != 0)
1340 return ERR_PTR(-EINVAL);
1341
1342 guard(mutex)(&dev->lock);
1343
1344 hog = kzalloc(sizeof(*hog), GFP_KERNEL);
1345 if (!hog)
1346 return ERR_PTR(-ENOMEM);
1347
1348 config_item_init_type_name(&hog->item, name,
1349 &gpio_sim_hog_config_type);
1350
1351 hog->dir = GPIOD_IN;
1352 hog->name = NULL;
1353 hog->parent = line;
1354 line->hog = hog;
1355
1356 return &hog->item;
1357}
1358
1359static void gpio_sim_line_config_group_release(struct config_item *item)
1360{
1361 struct gpio_sim_line *line = to_gpio_sim_line(item);
1362 struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
1363
1364 scoped_guard(mutex, &dev->lock)
1365 list_del(&line->siblings);
1366
1367 kfree(line->name);
1368 kfree(line);
1369}
1370
1371static struct configfs_item_operations gpio_sim_line_config_item_ops = {
1372 .release = gpio_sim_line_config_group_release,
1373};
1374
1375static struct configfs_group_operations gpio_sim_line_config_group_ops = {
1376 .make_item = gpio_sim_line_config_make_hog_item,
1377};
1378
1379static const struct config_item_type gpio_sim_line_config_type = {
1380 .ct_item_ops = &gpio_sim_line_config_item_ops,
1381 .ct_group_ops = &gpio_sim_line_config_group_ops,
1382 .ct_attrs = gpio_sim_line_config_attrs,
1383 .ct_owner = THIS_MODULE,
1384};
1385
1386static struct config_group *
1387gpio_sim_bank_config_make_line_group(struct config_group *group,
1388 const char *name)
1389{
1390 struct gpio_sim_bank *bank = to_gpio_sim_bank(&group->cg_item);
1391 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1392 struct gpio_sim_line *line;
1393 unsigned int offset;
1394 int ret, nchar;
1395
1396 ret = sscanf(name, "line%u%n", &offset, &nchar);
1397 if (ret != 1 || nchar != strlen(name))
1398 return ERR_PTR(-EINVAL);
1399
1400 guard(mutex)(&dev->lock);
1401
1402 if (gpio_sim_device_is_live(dev))
1403 return ERR_PTR(-EBUSY);
1404
1405 line = kzalloc(sizeof(*line), GFP_KERNEL);
1406 if (!line)
1407 return ERR_PTR(-ENOMEM);
1408
1409 config_group_init_type_name(&line->group, name,
1410 &gpio_sim_line_config_type);
1411
1412 line->parent = bank;
1413 line->offset = offset;
1414 list_add_tail(&line->siblings, &bank->line_list);
1415
1416 return &line->group;
1417}
1418
1419static void gpio_sim_bank_config_group_release(struct config_item *item)
1420{
1421 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1422 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1423
1424 scoped_guard(mutex, &dev->lock)
1425 list_del(&bank->siblings);
1426
1427 kfree(bank->label);
1428 kfree(bank);
1429}
1430
1431static struct configfs_item_operations gpio_sim_bank_config_item_ops = {
1432 .release = gpio_sim_bank_config_group_release,
1433};
1434
1435static struct configfs_group_operations gpio_sim_bank_config_group_ops = {
1436 .make_group = gpio_sim_bank_config_make_line_group,
1437};
1438
1439static const struct config_item_type gpio_sim_bank_config_group_type = {
1440 .ct_item_ops = &gpio_sim_bank_config_item_ops,
1441 .ct_group_ops = &gpio_sim_bank_config_group_ops,
1442 .ct_attrs = gpio_sim_bank_config_attrs,
1443 .ct_owner = THIS_MODULE,
1444};
1445
1446static struct config_group *
1447gpio_sim_device_config_make_bank_group(struct config_group *group,
1448 const char *name)
1449{
1450 struct gpio_sim_device *dev = to_gpio_sim_device(&group->cg_item);
1451 struct gpio_sim_bank *bank;
1452
1453 guard(mutex)(&dev->lock);
1454
1455 if (gpio_sim_device_is_live(dev))
1456 return ERR_PTR(-EBUSY);
1457
1458 bank = kzalloc(sizeof(*bank), GFP_KERNEL);
1459 if (!bank)
1460 return ERR_PTR(-ENOMEM);
1461
1462 config_group_init_type_name(&bank->group, name,
1463 &gpio_sim_bank_config_group_type);
1464 bank->num_lines = 1;
1465 bank->parent = dev;
1466 INIT_LIST_HEAD(&bank->line_list);
1467 list_add_tail(&bank->siblings, &dev->bank_list);
1468
1469 return &bank->group;
1470}
1471
1472static void gpio_sim_device_config_group_release(struct config_item *item)
1473{
1474 struct gpio_sim_device *dev = to_gpio_sim_device(item);
1475
1476 scoped_guard(mutex, &dev->lock) {
1477 if (gpio_sim_device_is_live(dev))
1478 gpio_sim_device_deactivate(dev);
1479 }
1480
1481 mutex_destroy(&dev->lock);
1482 ida_free(&gpio_sim_ida, dev->id);
1483 kfree(dev);
1484}
1485
1486static struct configfs_item_operations gpio_sim_device_config_item_ops = {
1487 .release = gpio_sim_device_config_group_release,
1488};
1489
1490static struct configfs_group_operations gpio_sim_device_config_group_ops = {
1491 .make_group = gpio_sim_device_config_make_bank_group,
1492};
1493
1494static const struct config_item_type gpio_sim_device_config_group_type = {
1495 .ct_item_ops = &gpio_sim_device_config_item_ops,
1496 .ct_group_ops = &gpio_sim_device_config_group_ops,
1497 .ct_attrs = gpio_sim_device_config_attrs,
1498 .ct_owner = THIS_MODULE,
1499};
1500
1501static struct config_group *
1502gpio_sim_config_make_device_group(struct config_group *group, const char *name)
1503{
1504 int id;
1505
1506 struct gpio_sim_device *dev __free(kfree) = kzalloc(sizeof(*dev),
1507 GFP_KERNEL);
1508 if (!dev)
1509 return ERR_PTR(-ENOMEM);
1510
1511 id = ida_alloc(&gpio_sim_ida, GFP_KERNEL);
1512 if (id < 0)
1513 return ERR_PTR(id);
1514
1515 config_group_init_type_name(&dev->group, name,
1516 &gpio_sim_device_config_group_type);
1517 dev->id = id;
1518 mutex_init(&dev->lock);
1519 INIT_LIST_HEAD(&dev->bank_list);
1520
1521 dev->bus_notifier.notifier_call = gpio_sim_bus_notifier_call;
1522 init_completion(&dev->probe_completion);
1523
1524 return &no_free_ptr(dev)->group;
1525}
1526
1527static struct configfs_group_operations gpio_sim_config_group_ops = {
1528 .make_group = gpio_sim_config_make_device_group,
1529};
1530
1531static const struct config_item_type gpio_sim_config_type = {
1532 .ct_group_ops = &gpio_sim_config_group_ops,
1533 .ct_owner = THIS_MODULE,
1534};
1535
1536static struct configfs_subsystem gpio_sim_config_subsys = {
1537 .su_group = {
1538 .cg_item = {
1539 .ci_namebuf = "gpio-sim",
1540 .ci_type = &gpio_sim_config_type,
1541 },
1542 },
1543};
1544
1545static int __init gpio_sim_init(void)
1546{
1547 int ret;
1548
1549 ret = platform_driver_register(&gpio_sim_driver);
1550 if (ret) {
1551 pr_err("Error %d while registering the platform driver\n", ret);
1552 return ret;
1553 }
1554
1555 config_group_init(&gpio_sim_config_subsys.su_group);
1556 mutex_init(&gpio_sim_config_subsys.su_mutex);
1557 ret = configfs_register_subsystem(&gpio_sim_config_subsys);
1558 if (ret) {
1559 pr_err("Error %d while registering the configfs subsystem %s\n",
1560 ret, gpio_sim_config_subsys.su_group.cg_item.ci_namebuf);
1561 mutex_destroy(&gpio_sim_config_subsys.su_mutex);
1562 platform_driver_unregister(&gpio_sim_driver);
1563 return ret;
1564 }
1565
1566 return 0;
1567}
1568module_init(gpio_sim_init);
1569
1570static void __exit gpio_sim_exit(void)
1571{
1572 configfs_unregister_subsystem(&gpio_sim_config_subsys);
1573 mutex_destroy(&gpio_sim_config_subsys.su_mutex);
1574 platform_driver_unregister(&gpio_sim_driver);
1575}
1576module_exit(gpio_sim_exit);
1577
1578MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>");
1579MODULE_DESCRIPTION("GPIO Simulator Module");
1580MODULE_LICENSE("GPL");