1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * GPIO testing driver based on configfs.
5 * Copyright (C) 2021 Bartosz Golaszewski <brgl@bgdev.pl>
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
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 */
44 static DEFINE_IDA(gpio_sim_ida);
46 struct gpio_sim_chip {
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;
55 const struct attribute_group **attr_groups;
58 struct gpio_sim_attribute {
59 struct device_attribute dev_attr;
63 static struct gpio_sim_attribute *
64 to_gpio_sim_attr(struct device_attribute *dev_attr)
66 return container_of(dev_attr, struct gpio_sim_attribute, dev_attr);
69 static int gpio_sim_apply_pull(struct gpio_sim_chip *chip,
70 unsigned int offset, int value)
72 int irq, irq_type, ret;
74 guard(mutex)(&chip->lock);
76 if (test_bit(offset, chip->request_map) &&
77 test_bit(offset, chip->direction_map)) {
78 if (value == !!test_bit(offset, chip->value_map))
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.
87 irq = irq_find_mapping(chip->irq_sim, offset);
91 irq_type = irq_get_trigger_type(irq);
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,
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);
109 __assign_bit(offset, chip->pull_map, value);
113 static int gpio_sim_get(struct gpio_chip *gc, unsigned int offset)
115 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
117 guard(mutex)(&chip->lock);
119 return !!test_bit(offset, chip->value_map);
122 static void gpio_sim_set(struct gpio_chip *gc, unsigned int offset, int value)
124 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
126 scoped_guard(mutex, &chip->lock)
127 __assign_bit(offset, chip->value_map, value);
130 static int gpio_sim_get_multiple(struct gpio_chip *gc,
131 unsigned long *mask, unsigned long *bits)
133 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
135 scoped_guard(mutex, &chip->lock)
136 bitmap_replace(bits, bits, chip->value_map, mask, gc->ngpio);
141 static void gpio_sim_set_multiple(struct gpio_chip *gc,
142 unsigned long *mask, unsigned long *bits)
144 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
146 scoped_guard(mutex, &chip->lock)
147 bitmap_replace(chip->value_map, chip->value_map, bits, mask,
151 static int gpio_sim_direction_output(struct gpio_chip *gc,
152 unsigned int offset, int value)
154 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
156 scoped_guard(mutex, &chip->lock) {
157 __clear_bit(offset, chip->direction_map);
158 __assign_bit(offset, chip->value_map, value);
164 static int gpio_sim_direction_input(struct gpio_chip *gc, unsigned int offset)
166 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
168 scoped_guard(mutex, &chip->lock)
169 __set_bit(offset, chip->direction_map);
174 static int gpio_sim_get_direction(struct gpio_chip *gc, unsigned int offset)
176 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
179 scoped_guard(mutex, &chip->lock)
180 direction = !!test_bit(offset, chip->direction_map);
182 return direction ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT;
185 static int gpio_sim_set_config(struct gpio_chip *gc, unsigned int offset,
186 unsigned long config)
188 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
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);
202 static int gpio_sim_to_irq(struct gpio_chip *gc, unsigned int offset)
204 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
206 return irq_create_mapping(chip->irq_sim, offset);
209 static int gpio_sim_request(struct gpio_chip *gc, unsigned int offset)
211 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
213 scoped_guard(mutex, &chip->lock)
214 __set_bit(offset, chip->request_map);
219 static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset)
221 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
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);
230 static void gpio_sim_dbg_show(struct seq_file *seq, struct gpio_chip *gc)
232 struct gpio_sim_chip *chip = gpiochip_get_data(gc);
236 guard(mutex)(&chip->lock);
238 for_each_hwgpio(gc, i, label)
239 seq_printf(seq, " gpio-%-3d (%s) %s,%s\n",
242 test_bit(i, chip->direction_map) ? "input" :
243 test_bit(i, chip->value_map) ? "output-high" :
245 test_bit(i, chip->pull_map) ? "pull-up" :
249 static ssize_t gpio_sim_sysfs_val_show(struct device *dev,
250 struct device_attribute *attr, char *buf)
252 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
253 struct gpio_sim_chip *chip = dev_get_drvdata(dev);
256 scoped_guard(mutex, &chip->lock)
257 val = !!test_bit(line_attr->offset, chip->value_map);
259 return sysfs_emit(buf, "%d\n", val);
262 static ssize_t gpio_sim_sysfs_val_store(struct device *dev,
263 struct device_attribute *attr,
264 const char *buf, size_t count)
267 * Not assigning this function will result in write() returning -EIO
268 * which is confusing. Return -EPERM explicitly.
273 static const char *const gpio_sim_sysfs_pull_strings[] = {
278 static ssize_t gpio_sim_sysfs_pull_show(struct device *dev,
279 struct device_attribute *attr,
282 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
283 struct gpio_sim_chip *chip = dev_get_drvdata(dev);
286 scoped_guard(mutex, &chip->lock)
287 pull = !!test_bit(line_attr->offset, chip->pull_map);
289 return sysfs_emit(buf, "%s\n", gpio_sim_sysfs_pull_strings[pull]);
292 static ssize_t gpio_sim_sysfs_pull_store(struct device *dev,
293 struct device_attribute *attr,
294 const char *buf, size_t len)
296 struct gpio_sim_attribute *line_attr = to_gpio_sim_attr(attr);
297 struct gpio_sim_chip *chip = dev_get_drvdata(dev);
300 pull = sysfs_match_string(gpio_sim_sysfs_pull_strings, buf);
304 ret = gpio_sim_apply_pull(chip, line_attr->offset, pull);
311 static void gpio_sim_mutex_destroy(void *data)
313 struct mutex *lock = data;
318 static void gpio_sim_put_device(void *data)
320 struct device *dev = data;
325 static void gpio_sim_dispose_mappings(void *data)
327 struct gpio_sim_chip *chip = data;
330 for (i = 0; i < chip->gc.ngpio; i++)
331 irq_dispose_mapping(irq_find_mapping(chip->irq_sim, i));
334 static void gpio_sim_sysfs_remove(void *data)
336 struct gpio_sim_chip *chip = data;
338 sysfs_remove_groups(&chip->dev->kobj, chip->attr_groups);
341 static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip)
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;
351 chip->attr_groups = devm_kcalloc(dev, sizeof(*chip->attr_groups),
352 num_lines + 1, GFP_KERNEL);
353 if (!chip->attr_groups)
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),
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)
365 attr_group->name = devm_kasprintf(dev, GFP_KERNEL,
367 if (!attr_group->name)
370 val_attr->offset = pull_attr->offset = i;
372 val_dev_attr = &val_attr->dev_attr;
373 pull_dev_attr = &pull_attr->dev_attr;
375 sysfs_attr_init(&val_dev_attr->attr);
376 sysfs_attr_init(&pull_dev_attr->attr);
378 val_dev_attr->attr.name = "value";
379 pull_dev_attr->attr.name = "pull";
381 val_dev_attr->attr.mode = pull_dev_attr->attr.mode = 0644;
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;
388 attrs[0] = &val_dev_attr->attr;
389 attrs[1] = &pull_dev_attr->attr;
391 attr_group->attrs = attrs;
392 chip->attr_groups[i] = attr_group;
395 ret = sysfs_create_groups(&chip->dev->kobj, chip->attr_groups);
399 return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip);
402 static int gpio_sim_dev_match_fwnode(struct device *dev, void *data)
404 return device_match_fwnode(dev, data);
407 static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
409 struct gpio_sim_chip *chip;
410 struct gpio_chip *gc;
415 ret = fwnode_property_read_u32(swnode, "ngpios", &num_lines);
419 if (num_lines > GPIO_SIM_NGPIO_MAX)
422 ret = fwnode_property_read_string(swnode, "gpio-sim,label", &label);
424 label = devm_kasprintf(dev, GFP_KERNEL, "%s:%pfwP",
425 dev_name(dev), swnode);
430 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
434 chip->request_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL);
435 if (!chip->request_map)
438 chip->direction_map = devm_bitmap_alloc(dev, num_lines, GFP_KERNEL);
439 if (!chip->direction_map)
442 /* Default to input mode. */
443 bitmap_fill(chip->direction_map, num_lines);
445 chip->value_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL);
446 if (!chip->value_map)
449 chip->pull_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL);
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);
457 ret = devm_add_action_or_reset(dev, gpio_sim_dispose_mappings, chip);
461 mutex_init(&chip->lock);
462 ret = devm_add_action_or_reset(dev, gpio_sim_mutex_destroy,
469 gc->ngpio = num_lines;
471 gc->owner = THIS_MODULE;
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;
488 ret = devm_gpiochip_add_data(dev, gc, chip);
492 chip->dev = device_find_child(dev, swnode, gpio_sim_dev_match_fwnode);
496 ret = devm_add_action_or_reset(dev, gpio_sim_put_device, chip->dev);
500 /* Used by sysfs callbacks. */
501 dev_set_drvdata(chip->dev, chip);
503 return gpio_sim_setup_sysfs(chip);
506 static int gpio_sim_probe(struct platform_device *pdev)
508 struct device *dev = &pdev->dev;
509 struct fwnode_handle *swnode;
512 device_for_each_child_node(dev, swnode) {
513 ret = gpio_sim_add_bank(swnode, dev);
515 fwnode_handle_put(swnode);
523 static const struct of_device_id gpio_sim_of_match[] = {
524 { .compatible = "gpio-simulator" },
527 MODULE_DEVICE_TABLE(of, gpio_sim_of_match);
529 static struct platform_driver gpio_sim_driver = {
532 .of_match_table = gpio_sim_of_match,
534 .probe = gpio_sim_probe,
537 struct gpio_sim_device {
538 struct config_group group;
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
545 struct platform_device *pdev;
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.
554 * We use this lock for protecting all data structures owned by this
560 * This is used to synchronously wait for the driver's probe to complete
561 * and notify the user-space about any errors.
563 struct notifier_block bus_notifier;
564 struct completion probe_completion;
567 struct gpiod_hog *hogs;
569 struct list_head bank_list;
572 /* This is called with dev->lock already taken. */
573 static int gpio_sim_bus_notifier_call(struct notifier_block *nb,
574 unsigned long action, void *data)
576 struct gpio_sim_device *simdev = container_of(nb,
577 struct gpio_sim_device,
579 struct device *dev = data;
582 snprintf(devname, sizeof(devname), "gpio-sim.%u", simdev->id);
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;
592 complete(&simdev->probe_completion);
599 static struct gpio_sim_device *to_gpio_sim_device(struct config_item *item)
601 struct config_group *group = to_config_group(item);
603 return container_of(group, struct gpio_sim_device, group);
606 struct gpio_sim_bank {
607 struct config_group group;
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...
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
620 * Same for other structures.
622 struct gpio_sim_device *parent;
623 struct list_head siblings;
626 unsigned int num_lines;
628 struct list_head line_list;
630 struct fwnode_handle *swnode;
633 static struct gpio_sim_bank *to_gpio_sim_bank(struct config_item *item)
635 struct config_group *group = to_config_group(item);
637 return container_of(group, struct gpio_sim_bank, group);
640 static bool gpio_sim_bank_has_label(struct gpio_sim_bank *bank)
642 return bank->label && *bank->label;
645 static struct gpio_sim_device *
646 gpio_sim_bank_get_device(struct gpio_sim_bank *bank)
653 struct gpio_sim_line {
654 struct config_group group;
656 struct gpio_sim_bank *parent;
657 struct list_head siblings;
662 /* There can only be one hog per line. */
663 struct gpio_sim_hog *hog;
666 static struct gpio_sim_line *to_gpio_sim_line(struct config_item *item)
668 struct config_group *group = to_config_group(item);
670 return container_of(group, struct gpio_sim_line, group);
673 static struct gpio_sim_device *
674 gpio_sim_line_get_device(struct gpio_sim_line *line)
676 struct gpio_sim_bank *bank = line->parent;
678 return gpio_sim_bank_get_device(bank);
681 struct gpio_sim_hog {
682 struct config_item item;
683 struct gpio_sim_line *parent;
689 static struct gpio_sim_hog *to_gpio_sim_hog(struct config_item *item)
691 return container_of(item, struct gpio_sim_hog, item);
694 static struct gpio_sim_device *gpio_sim_hog_get_device(struct gpio_sim_hog *hog)
696 struct gpio_sim_line *line = hog->parent;
698 return gpio_sim_line_get_device(line);
701 static bool gpio_sim_device_is_live(struct gpio_sim_device *dev)
703 lockdep_assert_held(&dev->lock);
708 static char *gpio_sim_strdup_trimmed(const char *str, size_t count)
712 trimmed = kstrndup(skip_spaces(str), count, GFP_KERNEL);
716 return strim(trimmed);
719 static ssize_t gpio_sim_device_config_dev_name_show(struct config_item *item,
722 struct gpio_sim_device *dev = to_gpio_sim_device(item);
723 struct platform_device *pdev;
725 guard(mutex)(&dev->lock);
729 return sprintf(page, "%s\n", dev_name(&pdev->dev));
731 return sprintf(page, "gpio-sim.%d\n", dev->id);
734 CONFIGFS_ATTR_RO(gpio_sim_device_config_, dev_name);
737 gpio_sim_device_config_live_show(struct config_item *item, char *page)
739 struct gpio_sim_device *dev = to_gpio_sim_device(item);
742 scoped_guard(mutex, &dev->lock)
743 live = gpio_sim_device_is_live(dev);
745 return sprintf(page, "%c\n", live ? '1' : '0');
748 static unsigned int gpio_sim_get_line_names_size(struct gpio_sim_bank *bank)
750 struct gpio_sim_line *line;
751 unsigned int size = 0;
753 list_for_each_entry(line, &bank->line_list, siblings) {
754 if (!line->name || (line->offset >= bank->num_lines))
757 size = max(size, line->offset + 1);
764 gpio_sim_set_line_names(struct gpio_sim_bank *bank, char **line_names)
766 struct gpio_sim_line *line;
768 list_for_each_entry(line, &bank->line_list, siblings) {
769 if (!line->name || (line->offset >= bank->num_lines))
772 line_names[line->offset] = line->name;
776 static void gpio_sim_remove_hogs(struct gpio_sim_device *dev)
778 struct gpiod_hog *hog;
783 gpiod_remove_hogs(dev->hogs);
785 for (hog = dev->hogs; hog->chip_label; hog++) {
786 kfree(hog->chip_label);
787 kfree(hog->line_name);
794 static int gpio_sim_add_hogs(struct gpio_sim_device *dev)
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;
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)
814 /* Allocate one more for the sentinel. */
815 dev->hogs = kcalloc(num_hogs + 1, sizeof(*dev->hogs), GFP_KERNEL);
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)
827 hog = &dev->hogs[idx++];
830 * We need to make this string manually because at this
831 * point the device doesn't exist yet and so dev_name()
834 if (gpio_sim_bank_has_label(bank))
835 hog->chip_label = kstrdup(bank->label,
838 hog->chip_label = kasprintf(GFP_KERNEL,
842 if (!hog->chip_label) {
843 gpio_sim_remove_hogs(dev);
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
853 if (line->hog->name) {
854 hog->line_name = kstrdup(line->hog->name,
856 if (!hog->line_name) {
857 gpio_sim_remove_hogs(dev);
862 hog->chip_hwnum = line->offset;
863 hog->dflags = line->hog->dir;
867 gpiod_add_hogs(dev->hogs);
872 static struct fwnode_handle *
873 gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank,
874 struct fwnode_handle *parent)
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;
880 memset(properties, 0, sizeof(properties));
882 properties[prop_idx++] = PROPERTY_ENTRY_U32("ngpios", bank->num_lines);
884 if (gpio_sim_bank_has_label(bank))
885 properties[prop_idx++] = PROPERTY_ENTRY_STRING("gpio-sim,label",
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),
893 return ERR_PTR(-ENOMEM);
895 gpio_sim_set_line_names(bank, line_names);
897 properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
899 line_names, line_names_size);
902 return fwnode_create_software_node(properties, parent);
905 static void gpio_sim_remove_swnode_recursive(struct fwnode_handle *swnode)
907 struct fwnode_handle *child;
909 fwnode_for_each_child_node(swnode, child)
910 fwnode_remove_software_node(child);
912 fwnode_remove_software_node(swnode);
915 static bool gpio_sim_bank_labels_non_unique(struct gpio_sim_device *dev)
917 struct gpio_sim_bank *this, *pos;
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))
924 if (strcmp(this->label, pos->label) == 0)
932 static int gpio_sim_device_activate(struct gpio_sim_device *dev)
934 struct platform_device_info pdevinfo;
935 struct fwnode_handle *swnode;
936 struct platform_device *pdev;
937 struct gpio_sim_bank *bank;
940 lockdep_assert_held(&dev->lock);
942 if (list_empty(&dev->bank_list))
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
950 if (gpio_sim_bank_labels_non_unique(dev))
953 memset(&pdevinfo, 0, sizeof(pdevinfo));
955 swnode = fwnode_create_software_node(NULL, NULL);
957 return PTR_ERR(swnode);
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);
968 ret = gpio_sim_add_hogs(dev);
970 gpio_sim_remove_swnode_recursive(swnode);
974 pdevinfo.name = "gpio-sim";
975 pdevinfo.fwnode = swnode;
976 pdevinfo.id = dev->id;
978 reinit_completion(&dev->probe_completion);
979 dev->driver_bound = false;
980 bus_register_notifier(&platform_bus_type, &dev->bus_notifier);
982 pdev = platform_device_register_full(&pdevinfo);
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);
990 wait_for_completion(&dev->probe_completion);
991 bus_unregister_notifier(&platform_bus_type, &dev->bus_notifier);
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);
1006 static void gpio_sim_device_deactivate(struct gpio_sim_device *dev)
1008 struct fwnode_handle *swnode;
1010 lockdep_assert_held(&dev->lock);
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);
1020 gpio_sim_device_config_live_store(struct config_item *item,
1021 const char *page, size_t count)
1023 struct gpio_sim_device *dev = to_gpio_sim_device(item);
1027 ret = kstrtobool(page, &live);
1031 guard(mutex)(&dev->lock);
1033 if (live == gpio_sim_device_is_live(dev))
1036 ret = gpio_sim_device_activate(dev);
1038 gpio_sim_device_deactivate(dev);
1040 return ret ?: count;
1043 CONFIGFS_ATTR(gpio_sim_device_config_, live);
1045 static struct configfs_attribute *gpio_sim_device_config_attrs[] = {
1046 &gpio_sim_device_config_attr_dev_name,
1047 &gpio_sim_device_config_attr_live,
1051 struct gpio_sim_chip_name_ctx {
1052 struct fwnode_handle *swnode;
1056 static int gpio_sim_emit_chip_name(struct device *dev, void *data)
1058 struct gpio_sim_chip_name_ctx *ctx = data;
1060 /* This would be the sysfs device exported in /sys/class/gpio. */
1064 if (device_match_fwnode(dev, ctx->swnode))
1065 return sprintf(ctx->page, "%s\n", dev_name(dev));
1070 static ssize_t gpio_sim_bank_config_chip_name_show(struct config_item *item,
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 };
1077 guard(mutex)(&dev->lock);
1079 if (gpio_sim_device_is_live(dev))
1080 return device_for_each_child(&dev->pdev->dev, &ctx,
1081 gpio_sim_emit_chip_name);
1083 return sprintf(page, "none\n");
1086 CONFIGFS_ATTR_RO(gpio_sim_bank_config_, chip_name);
1089 gpio_sim_bank_config_label_show(struct config_item *item, char *page)
1091 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1092 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1094 guard(mutex)(&dev->lock);
1096 return sprintf(page, "%s\n", bank->label ?: "");
1099 static ssize_t gpio_sim_bank_config_label_store(struct config_item *item,
1100 const char *page, size_t count)
1102 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1103 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1106 guard(mutex)(&dev->lock);
1108 if (gpio_sim_device_is_live(dev))
1111 trimmed = gpio_sim_strdup_trimmed(page, count);
1116 bank->label = trimmed;
1121 CONFIGFS_ATTR(gpio_sim_bank_config_, label);
1124 gpio_sim_bank_config_num_lines_show(struct config_item *item, char *page)
1126 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1127 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1129 guard(mutex)(&dev->lock);
1131 return sprintf(page, "%u\n", bank->num_lines);
1135 gpio_sim_bank_config_num_lines_store(struct config_item *item,
1136 const char *page, size_t count)
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;
1143 ret = kstrtouint(page, 0, &num_lines);
1150 guard(mutex)(&dev->lock);
1152 if (gpio_sim_device_is_live(dev))
1155 bank->num_lines = num_lines;
1160 CONFIGFS_ATTR(gpio_sim_bank_config_, num_lines);
1162 static 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,
1170 gpio_sim_line_config_name_show(struct config_item *item, char *page)
1172 struct gpio_sim_line *line = to_gpio_sim_line(item);
1173 struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
1175 guard(mutex)(&dev->lock);
1177 return sprintf(page, "%s\n", line->name ?: "");
1180 static ssize_t gpio_sim_line_config_name_store(struct config_item *item,
1181 const char *page, size_t count)
1183 struct gpio_sim_line *line = to_gpio_sim_line(item);
1184 struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
1187 guard(mutex)(&dev->lock);
1189 if (gpio_sim_device_is_live(dev))
1192 trimmed = gpio_sim_strdup_trimmed(page, count);
1197 line->name = trimmed;
1202 CONFIGFS_ATTR(gpio_sim_line_config_, name);
1204 static struct configfs_attribute *gpio_sim_line_config_attrs[] = {
1205 &gpio_sim_line_config_attr_name,
1209 static ssize_t gpio_sim_hog_config_name_show(struct config_item *item,
1212 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1213 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1215 guard(mutex)(&dev->lock);
1217 return sprintf(page, "%s\n", hog->name ?: "");
1220 static ssize_t gpio_sim_hog_config_name_store(struct config_item *item,
1221 const char *page, size_t count)
1223 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1224 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1227 guard(mutex)(&dev->lock);
1229 if (gpio_sim_device_is_live(dev))
1232 trimmed = gpio_sim_strdup_trimmed(page, count);
1237 hog->name = trimmed;
1242 CONFIGFS_ATTR(gpio_sim_hog_config_, name);
1244 static ssize_t gpio_sim_hog_config_direction_show(struct config_item *item,
1247 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1248 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1252 scoped_guard(mutex, &dev->lock)
1259 case GPIOD_OUT_HIGH:
1260 repr = "output-high";
1263 repr = "output-low";
1266 /* This would be a programmer bug. */
1267 WARN(1, "Unexpected hog direction value: %d", dir);
1271 return sprintf(page, "%s\n", repr);
1275 gpio_sim_hog_config_direction_store(struct config_item *item,
1276 const char *page, size_t count)
1278 struct gpio_sim_hog *hog = to_gpio_sim_hog(item);
1279 struct gpio_sim_device *dev = gpio_sim_hog_get_device(hog);
1282 guard(mutex)(&dev->lock);
1284 if (gpio_sim_device_is_live(dev))
1287 if (sysfs_streq(page, "input"))
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;
1301 CONFIGFS_ATTR(gpio_sim_hog_config_, direction);
1303 static struct configfs_attribute *gpio_sim_hog_config_attrs[] = {
1304 &gpio_sim_hog_config_attr_name,
1305 &gpio_sim_hog_config_attr_direction,
1309 static void gpio_sim_hog_config_item_release(struct config_item *item)
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);
1315 scoped_guard(mutex, &dev->lock)
1322 static struct configfs_item_operations gpio_sim_hog_config_item_ops = {
1323 .release = gpio_sim_hog_config_item_release,
1326 static 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,
1332 static struct config_item *
1333 gpio_sim_line_config_make_hog_item(struct config_group *group, const char *name)
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;
1339 if (strcmp(name, "hog") != 0)
1340 return ERR_PTR(-EINVAL);
1342 guard(mutex)(&dev->lock);
1344 hog = kzalloc(sizeof(*hog), GFP_KERNEL);
1346 return ERR_PTR(-ENOMEM);
1348 config_item_init_type_name(&hog->item, name,
1349 &gpio_sim_hog_config_type);
1351 hog->dir = GPIOD_IN;
1359 static void gpio_sim_line_config_group_release(struct config_item *item)
1361 struct gpio_sim_line *line = to_gpio_sim_line(item);
1362 struct gpio_sim_device *dev = gpio_sim_line_get_device(line);
1364 scoped_guard(mutex, &dev->lock)
1365 list_del(&line->siblings);
1371 static struct configfs_item_operations gpio_sim_line_config_item_ops = {
1372 .release = gpio_sim_line_config_group_release,
1375 static struct configfs_group_operations gpio_sim_line_config_group_ops = {
1376 .make_item = gpio_sim_line_config_make_hog_item,
1379 static 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,
1386 static struct config_group *
1387 gpio_sim_bank_config_make_line_group(struct config_group *group,
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;
1396 ret = sscanf(name, "line%u%n", &offset, &nchar);
1397 if (ret != 1 || nchar != strlen(name))
1398 return ERR_PTR(-EINVAL);
1400 guard(mutex)(&dev->lock);
1402 if (gpio_sim_device_is_live(dev))
1403 return ERR_PTR(-EBUSY);
1405 line = kzalloc(sizeof(*line), GFP_KERNEL);
1407 return ERR_PTR(-ENOMEM);
1409 config_group_init_type_name(&line->group, name,
1410 &gpio_sim_line_config_type);
1412 line->parent = bank;
1413 line->offset = offset;
1414 list_add_tail(&line->siblings, &bank->line_list);
1416 return &line->group;
1419 static void gpio_sim_bank_config_group_release(struct config_item *item)
1421 struct gpio_sim_bank *bank = to_gpio_sim_bank(item);
1422 struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
1424 scoped_guard(mutex, &dev->lock)
1425 list_del(&bank->siblings);
1431 static struct configfs_item_operations gpio_sim_bank_config_item_ops = {
1432 .release = gpio_sim_bank_config_group_release,
1435 static struct configfs_group_operations gpio_sim_bank_config_group_ops = {
1436 .make_group = gpio_sim_bank_config_make_line_group,
1439 static 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,
1446 static struct config_group *
1447 gpio_sim_device_config_make_bank_group(struct config_group *group,
1450 struct gpio_sim_device *dev = to_gpio_sim_device(&group->cg_item);
1451 struct gpio_sim_bank *bank;
1453 guard(mutex)(&dev->lock);
1455 if (gpio_sim_device_is_live(dev))
1456 return ERR_PTR(-EBUSY);
1458 bank = kzalloc(sizeof(*bank), GFP_KERNEL);
1460 return ERR_PTR(-ENOMEM);
1462 config_group_init_type_name(&bank->group, name,
1463 &gpio_sim_bank_config_group_type);
1464 bank->num_lines = 1;
1466 INIT_LIST_HEAD(&bank->line_list);
1467 list_add_tail(&bank->siblings, &dev->bank_list);
1469 return &bank->group;
1472 static void gpio_sim_device_config_group_release(struct config_item *item)
1474 struct gpio_sim_device *dev = to_gpio_sim_device(item);
1476 scoped_guard(mutex, &dev->lock) {
1477 if (gpio_sim_device_is_live(dev))
1478 gpio_sim_device_deactivate(dev);
1481 mutex_destroy(&dev->lock);
1482 ida_free(&gpio_sim_ida, dev->id);
1486 static struct configfs_item_operations gpio_sim_device_config_item_ops = {
1487 .release = gpio_sim_device_config_group_release,
1490 static struct configfs_group_operations gpio_sim_device_config_group_ops = {
1491 .make_group = gpio_sim_device_config_make_bank_group,
1494 static 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,
1501 static struct config_group *
1502 gpio_sim_config_make_device_group(struct config_group *group, const char *name)
1506 struct gpio_sim_device *dev __free(kfree) = kzalloc(sizeof(*dev),
1509 return ERR_PTR(-ENOMEM);
1511 id = ida_alloc(&gpio_sim_ida, GFP_KERNEL);
1515 config_group_init_type_name(&dev->group, name,
1516 &gpio_sim_device_config_group_type);
1518 mutex_init(&dev->lock);
1519 INIT_LIST_HEAD(&dev->bank_list);
1521 dev->bus_notifier.notifier_call = gpio_sim_bus_notifier_call;
1522 init_completion(&dev->probe_completion);
1524 return &no_free_ptr(dev)->group;
1527 static struct configfs_group_operations gpio_sim_config_group_ops = {
1528 .make_group = gpio_sim_config_make_device_group,
1531 static const struct config_item_type gpio_sim_config_type = {
1532 .ct_group_ops = &gpio_sim_config_group_ops,
1533 .ct_owner = THIS_MODULE,
1536 static struct configfs_subsystem gpio_sim_config_subsys = {
1539 .ci_namebuf = "gpio-sim",
1540 .ci_type = &gpio_sim_config_type,
1545 static int __init gpio_sim_init(void)
1549 ret = platform_driver_register(&gpio_sim_driver);
1551 pr_err("Error %d while registering the platform driver\n", ret);
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);
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);
1568 module_init(gpio_sim_init);
1570 static void __exit gpio_sim_exit(void)
1572 configfs_unregister_subsystem(&gpio_sim_config_subsys);
1573 mutex_destroy(&gpio_sim_config_subsys.su_mutex);
1574 platform_driver_unregister(&gpio_sim_driver);
1576 module_exit(gpio_sim_exit);
1578 MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>");
1579 MODULE_DESCRIPTION("GPIO Simulator Module");
1580 MODULE_LICENSE("GPL");