1 // SPDX-License-Identifier: GPL-2.0
3 #include <linux/bitmap.h>
4 #include <linux/kernel.h>
5 #include <linux/module.h>
6 #include <linux/interrupt.h>
8 #include <linux/spinlock.h>
9 #include <linux/list.h>
10 #include <linux/device.h>
11 #include <linux/err.h>
12 #include <linux/debugfs.h>
13 #include <linux/seq_file.h>
14 #include <linux/gpio.h>
15 #include <linux/idr.h>
16 #include <linux/slab.h>
17 #include <linux/acpi.h>
18 #include <linux/gpio/driver.h>
19 #include <linux/gpio/machine.h>
20 #include <linux/pinctrl/consumer.h>
22 #include <linux/compat.h>
23 #include <linux/file.h>
24 #include <uapi/linux/gpio.h>
27 #include "gpiolib-of.h"
28 #include "gpiolib-acpi.h"
29 #include "gpiolib-cdev.h"
30 #include "gpiolib-sysfs.h"
32 #define CREATE_TRACE_POINTS
33 #include <trace/events/gpio.h>
35 /* Implementation infrastructure for GPIO interfaces.
37 * The GPIO programming interface allows for inlining speed-critical
38 * get/set operations for common cases, so that access to SOC-integrated
39 * GPIOs can sometimes cost only an instruction or two per bit.
43 /* When debugging, extend minimal trust to callers and platform code.
44 * Also emit diagnostic messages that may help initial bringup, when
45 * board setup or driver bugs are most common.
47 * Otherwise, minimize overhead in what may be bitbanging codepaths.
50 #define extra_checks 1
52 #define extra_checks 0
55 /* Device and char device-related information */
56 static DEFINE_IDA(gpio_ida);
57 static dev_t gpio_devt;
58 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
59 static int gpio_bus_match(struct device *dev, struct device_driver *drv);
60 static struct bus_type gpio_bus_type = {
62 .match = gpio_bus_match,
66 * Number of GPIOs to use for the fast path in set array
68 #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
70 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
71 * While any GPIO is requested, its gpio_chip is not removable;
72 * each GPIO's "requested" flag serves as a lock and refcount.
74 DEFINE_SPINLOCK(gpio_lock);
76 static DEFINE_MUTEX(gpio_lookup_lock);
77 static LIST_HEAD(gpio_lookup_list);
78 LIST_HEAD(gpio_devices);
80 static DEFINE_MUTEX(gpio_machine_hogs_mutex);
81 static LIST_HEAD(gpio_machine_hogs);
83 static void gpiochip_free_hogs(struct gpio_chip *gc);
84 static int gpiochip_add_irqchip(struct gpio_chip *gc,
85 struct lock_class_key *lock_key,
86 struct lock_class_key *request_key);
87 static void gpiochip_irqchip_remove(struct gpio_chip *gc);
88 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc);
89 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc);
90 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc);
92 static bool gpiolib_initialized;
94 static inline void desc_set_label(struct gpio_desc *d, const char *label)
100 * gpio_to_desc - Convert a GPIO number to its descriptor
101 * @gpio: global GPIO number
104 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
105 * with the given number exists in the system.
107 struct gpio_desc *gpio_to_desc(unsigned gpio)
109 struct gpio_device *gdev;
112 spin_lock_irqsave(&gpio_lock, flags);
114 list_for_each_entry(gdev, &gpio_devices, list) {
115 if (gdev->base <= gpio &&
116 gdev->base + gdev->ngpio > gpio) {
117 spin_unlock_irqrestore(&gpio_lock, flags);
118 return &gdev->descs[gpio - gdev->base];
122 spin_unlock_irqrestore(&gpio_lock, flags);
124 if (!gpio_is_valid(gpio))
125 pr_warn("invalid GPIO %d\n", gpio);
129 EXPORT_SYMBOL_GPL(gpio_to_desc);
132 * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
133 * hardware number for this chip
135 * @hwnum: hardware number of the GPIO for this chip
138 * A pointer to the GPIO descriptor or ``ERR_PTR(-EINVAL)`` if no GPIO exists
139 * in the given chip for the specified hardware number.
141 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc,
144 struct gpio_device *gdev = gc->gpiodev;
146 if (hwnum >= gdev->ngpio)
147 return ERR_PTR(-EINVAL);
149 return &gdev->descs[hwnum];
151 EXPORT_SYMBOL_GPL(gpiochip_get_desc);
154 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
155 * @desc: GPIO descriptor
157 * This should disappear in the future but is needed since we still
158 * use GPIO numbers for error messages and sysfs nodes.
161 * The global GPIO number for the GPIO specified by its descriptor.
163 int desc_to_gpio(const struct gpio_desc *desc)
165 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
167 EXPORT_SYMBOL_GPL(desc_to_gpio);
171 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
172 * @desc: descriptor to return the chip of
174 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
176 if (!desc || !desc->gdev)
178 return desc->gdev->chip;
180 EXPORT_SYMBOL_GPL(gpiod_to_chip);
182 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
183 static int gpiochip_find_base(int ngpio)
185 struct gpio_device *gdev;
186 int base = ARCH_NR_GPIOS - ngpio;
188 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
189 /* found a free space? */
190 if (gdev->base + gdev->ngpio <= base)
193 /* nope, check the space right before the chip */
194 base = gdev->base - ngpio;
197 if (gpio_is_valid(base)) {
198 pr_debug("%s: found new base at %d\n", __func__, base);
201 pr_err("%s: cannot find free range\n", __func__);
207 * gpiod_get_direction - return the current direction of a GPIO
208 * @desc: GPIO to get the direction of
210 * Returns 0 for output, 1 for input, or an error code in case of error.
212 * This function may sleep if gpiod_cansleep() is true.
214 int gpiod_get_direction(struct gpio_desc *desc)
216 struct gpio_chip *gc;
220 gc = gpiod_to_chip(desc);
221 offset = gpio_chip_hwgpio(desc);
224 * Open drain emulation using input mode may incorrectly report
225 * input here, fix that up.
227 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) &&
228 test_bit(FLAG_IS_OUT, &desc->flags))
231 if (!gc->get_direction)
234 ret = gc->get_direction(gc, offset);
238 /* GPIOF_DIR_IN or other positive, otherwise GPIOF_DIR_OUT */
242 assign_bit(FLAG_IS_OUT, &desc->flags, !ret);
246 EXPORT_SYMBOL_GPL(gpiod_get_direction);
249 * Add a new chip to the global chips list, keeping the list of chips sorted
250 * by range(means [base, base + ngpio - 1]) order.
252 * Return -EBUSY if the new chip overlaps with some other chip's integer
255 static int gpiodev_add_to_list(struct gpio_device *gdev)
257 struct gpio_device *prev, *next;
259 if (list_empty(&gpio_devices)) {
260 /* initial entry in list */
261 list_add_tail(&gdev->list, &gpio_devices);
265 next = list_entry(gpio_devices.next, struct gpio_device, list);
266 if (gdev->base + gdev->ngpio <= next->base) {
267 /* add before first entry */
268 list_add(&gdev->list, &gpio_devices);
272 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
273 if (prev->base + prev->ngpio <= gdev->base) {
274 /* add behind last entry */
275 list_add_tail(&gdev->list, &gpio_devices);
279 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
280 /* at the end of the list */
281 if (&next->list == &gpio_devices)
284 /* add between prev and next */
285 if (prev->base + prev->ngpio <= gdev->base
286 && gdev->base + gdev->ngpio <= next->base) {
287 list_add(&gdev->list, &prev->list);
292 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
297 * Convert a GPIO name to its descriptor
298 * Note that there is no guarantee that GPIO names are globally unique!
299 * Hence this function will return, if it exists, a reference to the first GPIO
300 * line found that matches the given name.
302 static struct gpio_desc *gpio_name_to_desc(const char * const name)
304 struct gpio_device *gdev;
310 spin_lock_irqsave(&gpio_lock, flags);
312 list_for_each_entry(gdev, &gpio_devices, list) {
315 for (i = 0; i != gdev->ngpio; ++i) {
316 struct gpio_desc *desc = &gdev->descs[i];
321 if (!strcmp(desc->name, name)) {
322 spin_unlock_irqrestore(&gpio_lock, flags);
328 spin_unlock_irqrestore(&gpio_lock, flags);
334 * Take the names from gc->names and assign them to their GPIO descriptors.
335 * Warn if a name is already used for a GPIO line on a different GPIO chip.
338 * 1. Non-unique names are still accepted,
339 * 2. Name collisions within the same GPIO chip are not reported.
341 static int gpiochip_set_desc_names(struct gpio_chip *gc)
343 struct gpio_device *gdev = gc->gpiodev;
346 /* First check all names if they are unique */
347 for (i = 0; i != gc->ngpio; ++i) {
348 struct gpio_desc *gpio;
350 gpio = gpio_name_to_desc(gc->names[i]);
353 "Detected name collision for GPIO name '%s'\n",
357 /* Then add all names to the GPIO descriptors */
358 for (i = 0; i != gc->ngpio; ++i)
359 gdev->descs[i].name = gc->names[i];
365 * devprop_gpiochip_set_names - Set GPIO line names using device properties
366 * @chip: GPIO chip whose lines should be named, if possible
368 * Looks for device property "gpio-line-names" and if it exists assigns
369 * GPIO line names for the chip. The memory allocated for the assigned
370 * names belong to the underlying firmware node and should not be released
373 static int devprop_gpiochip_set_names(struct gpio_chip *chip)
375 struct gpio_device *gdev = chip->gpiodev;
376 struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
381 count = fwnode_property_string_array_count(fwnode, "gpio-line-names");
386 * When offset is set in the driver side we assume the driver internally
387 * is using more than one gpiochip per the same device. We have to stop
388 * setting friendly names if the specified ones with 'gpio-line-names'
389 * are less than the offset in the device itself. This means all the
390 * lines are not present for every single pin within all the internal
393 if (count <= chip->offset) {
394 dev_warn(&gdev->dev, "gpio-line-names too short (length %d), cannot map names for the gpiochip at offset %u\n",
395 count, chip->offset);
399 names = kcalloc(count, sizeof(*names), GFP_KERNEL);
403 ret = fwnode_property_read_string_array(fwnode, "gpio-line-names",
406 dev_warn(&gdev->dev, "failed to read GPIO line names\n");
412 * When more that one gpiochip per device is used, 'count' can
413 * contain at most number gpiochips x chip->ngpio. We have to
414 * correctly distribute all defined lines taking into account
415 * chip->offset as starting point from where we will assign
416 * the names to pins from the 'names' array. Since property
417 * 'gpio-line-names' cannot contains gaps, we have to be sure
418 * we only assign those pins that really exists since chip->ngpio
419 * can be different of the chip->offset.
421 count = (count > chip->offset) ? count - chip->offset : count;
422 if (count > chip->ngpio)
425 for (i = 0; i < count; i++)
426 gdev->descs[i].name = names[chip->offset + i];
433 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)
437 p = bitmap_alloc(gc->ngpio, GFP_KERNEL);
441 /* Assume by default all GPIOs are valid */
442 bitmap_fill(p, gc->ngpio);
447 static int gpiochip_alloc_valid_mask(struct gpio_chip *gc)
449 if (!(of_gpio_need_valid_mask(gc) || gc->init_valid_mask))
452 gc->valid_mask = gpiochip_allocate_mask(gc);
459 static int gpiochip_init_valid_mask(struct gpio_chip *gc)
461 if (gc->init_valid_mask)
462 return gc->init_valid_mask(gc,
469 static void gpiochip_free_valid_mask(struct gpio_chip *gc)
471 bitmap_free(gc->valid_mask);
472 gc->valid_mask = NULL;
475 static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
477 if (gc->add_pin_ranges)
478 return gc->add_pin_ranges(gc);
483 bool gpiochip_line_is_valid(const struct gpio_chip *gc,
486 /* No mask means all valid */
487 if (likely(!gc->valid_mask))
489 return test_bit(offset, gc->valid_mask);
491 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
493 static void gpiodevice_release(struct device *dev)
495 struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
498 spin_lock_irqsave(&gpio_lock, flags);
499 list_del(&gdev->list);
500 spin_unlock_irqrestore(&gpio_lock, flags);
502 ida_free(&gpio_ida, gdev->id);
503 kfree_const(gdev->label);
508 #ifdef CONFIG_GPIO_CDEV
509 #define gcdev_register(gdev, devt) gpiolib_cdev_register((gdev), (devt))
510 #define gcdev_unregister(gdev) gpiolib_cdev_unregister((gdev))
513 * gpiolib_cdev_register() indirectly calls device_add(), which is still
514 * required even when cdev is not selected.
516 #define gcdev_register(gdev, devt) device_add(&(gdev)->dev)
517 #define gcdev_unregister(gdev) device_del(&(gdev)->dev)
520 static int gpiochip_setup_dev(struct gpio_device *gdev)
524 ret = gcdev_register(gdev, gpio_devt);
528 ret = gpiochip_sysfs_register(gdev);
530 goto err_remove_device;
532 /* From this point, the .release() function cleans up gpio_device */
533 gdev->dev.release = gpiodevice_release;
534 dev_dbg(&gdev->dev, "registered GPIOs %d to %d on %s\n", gdev->base,
535 gdev->base + gdev->ngpio - 1, gdev->chip->label ? : "generic");
540 gcdev_unregister(gdev);
544 static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
546 struct gpio_desc *desc;
549 desc = gpiochip_get_desc(gc, hog->chip_hwnum);
551 chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,
556 if (test_bit(FLAG_IS_HOGGED, &desc->flags))
559 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
561 gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",
562 __func__, gc->label, hog->chip_hwnum, rv);
565 static void machine_gpiochip_add(struct gpio_chip *gc)
567 struct gpiod_hog *hog;
569 mutex_lock(&gpio_machine_hogs_mutex);
571 list_for_each_entry(hog, &gpio_machine_hogs, list) {
572 if (!strcmp(gc->label, hog->chip_label))
573 gpiochip_machine_hog(gc, hog);
576 mutex_unlock(&gpio_machine_hogs_mutex);
579 static void gpiochip_setup_devs(void)
581 struct gpio_device *gdev;
584 list_for_each_entry(gdev, &gpio_devices, list) {
585 ret = gpiochip_setup_dev(gdev);
588 "Failed to initialize gpio device (%d)\n", ret);
592 int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
593 struct lock_class_key *lock_key,
594 struct lock_class_key *request_key)
596 struct fwnode_handle *fwnode = gc->parent ? dev_fwnode(gc->parent) : NULL;
601 struct gpio_device *gdev;
604 * First: allocate and populate the internal stat container, and
605 * set up the struct device.
607 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
610 gdev->dev.bus = &gpio_bus_type;
611 gdev->dev.parent = gc->parent;
615 of_gpio_dev_init(gc, gdev);
616 acpi_gpio_dev_init(gc, gdev);
619 * Assign fwnode depending on the result of the previous calls,
620 * if none of them succeed, assign it to the parent's one.
622 gdev->dev.fwnode = dev_fwnode(&gdev->dev) ?: fwnode;
624 gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
630 ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
634 device_initialize(&gdev->dev);
635 if (gc->parent && gc->parent->driver)
636 gdev->owner = gc->parent->driver->owner;
638 /* TODO: remove chip->owner */
639 gdev->owner = gc->owner;
641 gdev->owner = THIS_MODULE;
643 gdev->descs = kcalloc(gc->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
646 goto err_free_dev_name;
649 if (gc->ngpio == 0) {
650 chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
655 if (gc->ngpio > FASTPATH_NGPIO)
656 chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n",
657 gc->ngpio, FASTPATH_NGPIO);
659 gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
665 gdev->ngpio = gc->ngpio;
668 spin_lock_irqsave(&gpio_lock, flags);
671 * TODO: this allocates a Linux GPIO number base in the global
672 * GPIO numberspace for this chip. In the long run we want to
673 * get *rid* of this numberspace and use only descriptors, but
674 * it may be a pipe dream. It will not happen before we get rid
675 * of the sysfs interface anyways.
678 base = gpiochip_find_base(gc->ngpio);
681 spin_unlock_irqrestore(&gpio_lock, flags);
685 * TODO: it should not be necessary to reflect the assigned
686 * base outside of the GPIO subsystem. Go over drivers and
687 * see if anyone makes use of this, else drop this and assign
694 ret = gpiodev_add_to_list(gdev);
696 spin_unlock_irqrestore(&gpio_lock, flags);
700 for (i = 0; i < gc->ngpio; i++)
701 gdev->descs[i].gdev = gdev;
703 spin_unlock_irqrestore(&gpio_lock, flags);
705 BLOCKING_INIT_NOTIFIER_HEAD(&gdev->notifier);
707 #ifdef CONFIG_PINCTRL
708 INIT_LIST_HEAD(&gdev->pin_ranges);
712 ret = gpiochip_set_desc_names(gc);
714 ret = devprop_gpiochip_set_names(gc);
716 goto err_remove_from_list;
718 ret = gpiochip_alloc_valid_mask(gc);
720 goto err_remove_from_list;
722 ret = of_gpiochip_add(gc);
724 goto err_free_gpiochip_mask;
726 ret = gpiochip_init_valid_mask(gc);
728 goto err_remove_of_chip;
730 for (i = 0; i < gc->ngpio; i++) {
731 struct gpio_desc *desc = &gdev->descs[i];
733 if (gc->get_direction && gpiochip_line_is_valid(gc, i)) {
734 assign_bit(FLAG_IS_OUT,
735 &desc->flags, !gc->get_direction(gc, i));
737 assign_bit(FLAG_IS_OUT,
738 &desc->flags, !gc->direction_input);
742 ret = gpiochip_add_pin_ranges(gc);
744 goto err_remove_of_chip;
746 acpi_gpiochip_add(gc);
748 machine_gpiochip_add(gc);
750 ret = gpiochip_irqchip_init_valid_mask(gc);
752 goto err_remove_acpi_chip;
754 ret = gpiochip_irqchip_init_hw(gc);
756 goto err_remove_acpi_chip;
758 ret = gpiochip_add_irqchip(gc, lock_key, request_key);
760 goto err_remove_irqchip_mask;
763 * By first adding the chardev, and then adding the device,
764 * we get a device node entry in sysfs under
765 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
766 * coldplug of device nodes and other udev business.
767 * We can do this only if gpiolib has been initialized.
768 * Otherwise, defer until later.
770 if (gpiolib_initialized) {
771 ret = gpiochip_setup_dev(gdev);
773 goto err_remove_irqchip;
778 gpiochip_irqchip_remove(gc);
779 err_remove_irqchip_mask:
780 gpiochip_irqchip_free_valid_mask(gc);
781 err_remove_acpi_chip:
782 acpi_gpiochip_remove(gc);
784 gpiochip_free_hogs(gc);
785 of_gpiochip_remove(gc);
786 err_free_gpiochip_mask:
787 gpiochip_remove_pin_ranges(gc);
788 gpiochip_free_valid_mask(gc);
789 err_remove_from_list:
790 spin_lock_irqsave(&gpio_lock, flags);
791 list_del(&gdev->list);
792 spin_unlock_irqrestore(&gpio_lock, flags);
794 kfree_const(gdev->label);
798 kfree(dev_name(&gdev->dev));
800 ida_free(&gpio_ida, gdev->id);
802 /* failures here can mean systems won't boot... */
803 if (ret != -EPROBE_DEFER) {
804 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
805 gdev->base, gdev->base + gdev->ngpio - 1,
806 gc->label ? : "generic", ret);
811 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
814 * gpiochip_get_data() - get per-subdriver data for the chip
818 * The per-subdriver data for the chip.
820 void *gpiochip_get_data(struct gpio_chip *gc)
822 return gc->gpiodev->data;
824 EXPORT_SYMBOL_GPL(gpiochip_get_data);
827 * gpiochip_remove() - unregister a gpio_chip
828 * @gc: the chip to unregister
830 * A gpio_chip with any GPIOs still requested may not be removed.
832 void gpiochip_remove(struct gpio_chip *gc)
834 struct gpio_device *gdev = gc->gpiodev;
838 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
839 gpiochip_sysfs_unregister(gdev);
840 gpiochip_free_hogs(gc);
841 /* Numb the device, cancelling all outstanding operations */
843 gpiochip_irqchip_remove(gc);
844 acpi_gpiochip_remove(gc);
845 of_gpiochip_remove(gc);
846 gpiochip_remove_pin_ranges(gc);
847 gpiochip_free_valid_mask(gc);
849 * We accept no more calls into the driver from this point, so
850 * NULL the driver data pointer
854 spin_lock_irqsave(&gpio_lock, flags);
855 for (i = 0; i < gdev->ngpio; i++) {
856 if (gpiochip_is_requested(gc, i))
859 spin_unlock_irqrestore(&gpio_lock, flags);
861 if (i != gdev->ngpio)
863 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
866 * The gpiochip side puts its use of the device to rest here:
867 * if there are no userspace clients, the chardev and device will
868 * be removed, else it will be dangling until the last user is
871 gcdev_unregister(gdev);
872 put_device(&gdev->dev);
874 EXPORT_SYMBOL_GPL(gpiochip_remove);
877 * gpiochip_find() - iterator for locating a specific gpio_chip
878 * @data: data to pass to match function
879 * @match: Callback function to check gpio_chip
881 * Similar to bus_find_device. It returns a reference to a gpio_chip as
882 * determined by a user supplied @match callback. The callback should return
883 * 0 if the device doesn't match and non-zero if it does. If the callback is
884 * non-zero, this function will return to the caller and not iterate over any
887 struct gpio_chip *gpiochip_find(void *data,
888 int (*match)(struct gpio_chip *gc,
891 struct gpio_device *gdev;
892 struct gpio_chip *gc = NULL;
895 spin_lock_irqsave(&gpio_lock, flags);
896 list_for_each_entry(gdev, &gpio_devices, list)
897 if (gdev->chip && match(gdev->chip, data)) {
902 spin_unlock_irqrestore(&gpio_lock, flags);
906 EXPORT_SYMBOL_GPL(gpiochip_find);
908 static int gpiochip_match_name(struct gpio_chip *gc, void *data)
910 const char *name = data;
912 return !strcmp(gc->label, name);
915 static struct gpio_chip *find_chip_by_name(const char *name)
917 return gpiochip_find((void *)name, gpiochip_match_name);
920 #ifdef CONFIG_GPIOLIB_IRQCHIP
923 * The following is irqchip helper code for gpiochips.
926 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
928 struct gpio_irq_chip *girq = &gc->irq;
933 return girq->init_hw(gc);
936 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
938 struct gpio_irq_chip *girq = &gc->irq;
940 if (!girq->init_valid_mask)
943 girq->valid_mask = gpiochip_allocate_mask(gc);
944 if (!girq->valid_mask)
947 girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
952 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
954 bitmap_free(gc->irq.valid_mask);
955 gc->irq.valid_mask = NULL;
958 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
961 if (!gpiochip_line_is_valid(gc, offset))
963 /* No mask means all valid */
964 if (likely(!gc->irq.valid_mask))
966 return test_bit(offset, gc->irq.valid_mask);
968 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
970 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
973 * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
975 * @gc: the gpiochip to set the irqchip hierarchical handler to
976 * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
977 * will then percolate up to the parent
979 static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
980 struct irq_chip *irqchip)
982 /* DT will deal with mapping each IRQ as we go along */
983 if (is_of_node(gc->irq.fwnode))
987 * This is for legacy and boardfile "irqchip" fwnodes: allocate
988 * irqs upfront instead of dynamically since we don't have the
989 * dynamic type of allocation that hardware description languages
990 * provide. Once all GPIO drivers using board files are gone from
991 * the kernel we can delete this code, but for a transitional period
992 * it is necessary to keep this around.
994 if (is_fwnode_irqchip(gc->irq.fwnode)) {
998 for (i = 0; i < gc->ngpio; i++) {
999 struct irq_fwspec fwspec;
1000 unsigned int parent_hwirq;
1001 unsigned int parent_type;
1002 struct gpio_irq_chip *girq = &gc->irq;
1005 * We call the child to parent translation function
1006 * only to check if the child IRQ is valid or not.
1007 * Just pick the rising edge type here as that is what
1008 * we likely need to support.
1010 ret = girq->child_to_parent_hwirq(gc, i,
1011 IRQ_TYPE_EDGE_RISING,
1015 chip_err(gc, "skip set-up on hwirq %d\n",
1020 fwspec.fwnode = gc->irq.fwnode;
1021 /* This is the hwirq for the GPIO line side of things */
1022 fwspec.param[0] = girq->child_offset_to_irq(gc, i);
1023 /* Just pick something */
1024 fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
1025 fwspec.param_count = 2;
1026 ret = __irq_domain_alloc_irqs(gc->irq.domain,
1027 /* just pick something */
1036 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
1043 chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
1048 static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
1049 struct irq_fwspec *fwspec,
1050 unsigned long *hwirq,
1053 /* We support standard DT translation */
1054 if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
1055 return irq_domain_translate_twocell(d, fwspec, hwirq, type);
1058 /* This is for board files and others not using DT */
1059 if (is_fwnode_irqchip(fwspec->fwnode)) {
1062 ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
1065 WARN_ON(*type == IRQ_TYPE_NONE);
1071 static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
1073 unsigned int nr_irqs,
1076 struct gpio_chip *gc = d->host_data;
1077 irq_hw_number_t hwirq;
1078 unsigned int type = IRQ_TYPE_NONE;
1079 struct irq_fwspec *fwspec = data;
1081 unsigned int parent_hwirq;
1082 unsigned int parent_type;
1083 struct gpio_irq_chip *girq = &gc->irq;
1087 * The nr_irqs parameter is always one except for PCI multi-MSI
1088 * so this should not happen.
1090 WARN_ON(nr_irqs != 1);
1092 ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
1096 chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
1098 ret = girq->child_to_parent_hwirq(gc, hwirq, type,
1099 &parent_hwirq, &parent_type);
1101 chip_err(gc, "can't look up hwirq %lu\n", hwirq);
1104 chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
1107 * We set handle_bad_irq because the .set_type() should
1108 * always be invoked and set the right type of handler.
1110 irq_domain_set_info(d,
1119 /* This parent only handles asserted level IRQs */
1120 parent_arg = girq->populate_parent_alloc_arg(gc, parent_hwirq, parent_type);
1124 chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
1126 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1127 ret = irq_domain_alloc_irqs_parent(d, irq, 1, parent_arg);
1129 * If the parent irqdomain is msi, the interrupts have already
1130 * been allocated, so the EEXIST is good.
1132 if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
1136 "failed to allocate parent hwirq %d for hwirq %lu\n",
1137 parent_hwirq, hwirq);
1143 static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
1144 unsigned int offset)
1149 static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
1151 ops->activate = gpiochip_irq_domain_activate;
1152 ops->deactivate = gpiochip_irq_domain_deactivate;
1153 ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
1154 ops->free = irq_domain_free_irqs_common;
1157 * We only allow overriding the translate() function for
1158 * hierarchical chips, and this should only be done if the user
1159 * really need something other than 1:1 translation.
1161 if (!ops->translate)
1162 ops->translate = gpiochip_hierarchy_irq_domain_translate;
1165 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1167 if (!gc->irq.child_to_parent_hwirq ||
1169 chip_err(gc, "missing irqdomain vital data\n");
1173 if (!gc->irq.child_offset_to_irq)
1174 gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
1176 if (!gc->irq.populate_parent_alloc_arg)
1177 gc->irq.populate_parent_alloc_arg =
1178 gpiochip_populate_parent_fwspec_twocell;
1180 gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
1182 gc->irq.domain = irq_domain_create_hierarchy(
1183 gc->irq.parent_domain,
1187 &gc->irq.child_irq_domain_ops,
1190 if (!gc->irq.domain)
1193 gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
1198 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1200 return !!gc->irq.parent_domain;
1203 void *gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
1204 unsigned int parent_hwirq,
1205 unsigned int parent_type)
1207 struct irq_fwspec *fwspec;
1209 fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
1213 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1214 fwspec->param_count = 2;
1215 fwspec->param[0] = parent_hwirq;
1216 fwspec->param[1] = parent_type;
1220 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
1222 void *gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
1223 unsigned int parent_hwirq,
1224 unsigned int parent_type)
1226 struct irq_fwspec *fwspec;
1228 fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
1232 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1233 fwspec->param_count = 4;
1234 fwspec->param[0] = 0;
1235 fwspec->param[1] = parent_hwirq;
1236 fwspec->param[2] = 0;
1237 fwspec->param[3] = parent_type;
1241 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
1245 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1250 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1255 #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
1258 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1259 * @d: the irqdomain used by this irqchip
1260 * @irq: the global irq number used by this GPIO irqchip irq
1261 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1263 * This function will set up the mapping for a certain IRQ line on a
1264 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1265 * stored inside the gpiochip.
1267 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1268 irq_hw_number_t hwirq)
1270 struct gpio_chip *gc = d->host_data;
1273 if (!gpiochip_irqchip_irq_valid(gc, hwirq))
1276 irq_set_chip_data(irq, gc);
1278 * This lock class tells lockdep that GPIO irqs are in a different
1279 * category than their parents, so it won't report false recursion.
1281 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1282 irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
1283 /* Chips that use nested thread handlers have them marked */
1284 if (gc->irq.threaded)
1285 irq_set_nested_thread(irq, 1);
1286 irq_set_noprobe(irq);
1288 if (gc->irq.num_parents == 1)
1289 ret = irq_set_parent(irq, gc->irq.parents[0]);
1290 else if (gc->irq.map)
1291 ret = irq_set_parent(irq, gc->irq.map[hwirq]);
1297 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1298 * is passed as default type.
1300 if (gc->irq.default_type != IRQ_TYPE_NONE)
1301 irq_set_irq_type(irq, gc->irq.default_type);
1305 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1307 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1309 struct gpio_chip *gc = d->host_data;
1311 if (gc->irq.threaded)
1312 irq_set_nested_thread(irq, 0);
1313 irq_set_chip_and_handler(irq, NULL, NULL);
1314 irq_set_chip_data(irq, NULL);
1316 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1318 static const struct irq_domain_ops gpiochip_domain_ops = {
1319 .map = gpiochip_irq_map,
1320 .unmap = gpiochip_irq_unmap,
1321 /* Virtually all GPIO irqchips are twocell:ed */
1322 .xlate = irq_domain_xlate_twocell,
1326 * TODO: move these activate/deactivate in under the hierarchicial
1327 * irqchip implementation as static once SPMI and SSBI (all external
1328 * users) are phased over.
1331 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1332 * @domain: The IRQ domain used by this IRQ chip
1333 * @data: Outermost irq_data associated with the IRQ
1334 * @reserve: If set, only reserve an interrupt vector instead of assigning one
1336 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1337 * used as the activate function for the &struct irq_domain_ops. The host_data
1338 * for the IRQ domain must be the &struct gpio_chip.
1340 int gpiochip_irq_domain_activate(struct irq_domain *domain,
1341 struct irq_data *data, bool reserve)
1343 struct gpio_chip *gc = domain->host_data;
1345 return gpiochip_lock_as_irq(gc, data->hwirq);
1347 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
1350 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1351 * @domain: The IRQ domain used by this IRQ chip
1352 * @data: Outermost irq_data associated with the IRQ
1354 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1355 * be used as the deactivate function for the &struct irq_domain_ops. The
1356 * host_data for the IRQ domain must be the &struct gpio_chip.
1358 void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1359 struct irq_data *data)
1361 struct gpio_chip *gc = domain->host_data;
1363 return gpiochip_unlock_as_irq(gc, data->hwirq);
1365 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
1367 static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)
1369 struct irq_domain *domain = gc->irq.domain;
1371 #ifdef CONFIG_GPIOLIB_IRQCHIP
1373 * Avoid race condition with other code, which tries to lookup
1374 * an IRQ before the irqchip has been properly registered,
1375 * i.e. while gpiochip is still being brought up.
1377 if (!gc->irq.initialized)
1378 return -EPROBE_DEFER;
1381 if (!gpiochip_irqchip_irq_valid(gc, offset))
1384 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1385 if (irq_domain_is_hierarchy(domain)) {
1386 struct irq_fwspec spec;
1388 spec.fwnode = domain->fwnode;
1389 spec.param_count = 2;
1390 spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
1391 spec.param[1] = IRQ_TYPE_NONE;
1393 return irq_create_fwspec_mapping(&spec);
1397 return irq_create_mapping(domain, offset);
1400 static int gpiochip_irq_reqres(struct irq_data *d)
1402 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1404 return gpiochip_reqres_irq(gc, d->hwirq);
1407 static void gpiochip_irq_relres(struct irq_data *d)
1409 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1411 gpiochip_relres_irq(gc, d->hwirq);
1414 static void gpiochip_irq_mask(struct irq_data *d)
1416 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1418 if (gc->irq.irq_mask)
1419 gc->irq.irq_mask(d);
1420 gpiochip_disable_irq(gc, d->hwirq);
1423 static void gpiochip_irq_unmask(struct irq_data *d)
1425 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1427 gpiochip_enable_irq(gc, d->hwirq);
1428 if (gc->irq.irq_unmask)
1429 gc->irq.irq_unmask(d);
1432 static void gpiochip_irq_enable(struct irq_data *d)
1434 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1436 gpiochip_enable_irq(gc, d->hwirq);
1437 gc->irq.irq_enable(d);
1440 static void gpiochip_irq_disable(struct irq_data *d)
1442 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1444 gc->irq.irq_disable(d);
1445 gpiochip_disable_irq(gc, d->hwirq);
1448 static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
1450 struct irq_chip *irqchip = gc->irq.chip;
1452 if (!irqchip->irq_request_resources &&
1453 !irqchip->irq_release_resources) {
1454 irqchip->irq_request_resources = gpiochip_irq_reqres;
1455 irqchip->irq_release_resources = gpiochip_irq_relres;
1457 if (WARN_ON(gc->irq.irq_enable))
1459 /* Check if the irqchip already has this hook... */
1460 if (irqchip->irq_enable == gpiochip_irq_enable ||
1461 irqchip->irq_mask == gpiochip_irq_mask) {
1463 * ...and if so, give a gentle warning that this is bad
1467 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1471 if (irqchip->irq_disable) {
1472 gc->irq.irq_disable = irqchip->irq_disable;
1473 irqchip->irq_disable = gpiochip_irq_disable;
1475 gc->irq.irq_mask = irqchip->irq_mask;
1476 irqchip->irq_mask = gpiochip_irq_mask;
1479 if (irqchip->irq_enable) {
1480 gc->irq.irq_enable = irqchip->irq_enable;
1481 irqchip->irq_enable = gpiochip_irq_enable;
1483 gc->irq.irq_unmask = irqchip->irq_unmask;
1484 irqchip->irq_unmask = gpiochip_irq_unmask;
1489 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1490 * @gc: the GPIO chip to add the IRQ chip to
1491 * @lock_key: lockdep class for IRQ lock
1492 * @request_key: lockdep class for IRQ request
1494 static int gpiochip_add_irqchip(struct gpio_chip *gc,
1495 struct lock_class_key *lock_key,
1496 struct lock_class_key *request_key)
1498 struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
1499 struct irq_chip *irqchip = gc->irq.chip;
1506 if (gc->irq.parent_handler && gc->can_sleep) {
1507 chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
1511 type = gc->irq.default_type;
1514 * Specifying a default trigger is a terrible idea if DT or ACPI is
1515 * used to configure the interrupts, as you may end up with
1516 * conflicting triggers. Tell the user, and reset to NONE.
1518 if (WARN(fwnode && type != IRQ_TYPE_NONE,
1519 "%pfw: Ignoring %u default trigger\n", fwnode, type))
1520 type = IRQ_TYPE_NONE;
1523 chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__);
1525 gc->to_irq = gpiochip_to_irq;
1526 gc->irq.default_type = type;
1527 gc->irq.lock_key = lock_key;
1528 gc->irq.request_key = request_key;
1530 /* If a parent irqdomain is provided, let's build a hierarchy */
1531 if (gpiochip_hierarchy_is_hierarchical(gc)) {
1532 int ret = gpiochip_hierarchy_add_domain(gc);
1536 /* Some drivers provide custom irqdomain ops */
1537 gc->irq.domain = irq_domain_create_simple(fwnode,
1540 gc->irq.domain_ops ?: &gpiochip_domain_ops,
1542 if (!gc->irq.domain)
1546 if (gc->irq.parent_handler) {
1547 void *data = gc->irq.parent_handler_data ?: gc;
1549 for (i = 0; i < gc->irq.num_parents; i++) {
1551 * The parent IRQ chip is already using the chip_data
1552 * for this IRQ chip, so our callbacks simply use the
1555 irq_set_chained_handler_and_data(gc->irq.parents[i],
1556 gc->irq.parent_handler,
1561 gpiochip_set_irq_hooks(gc);
1564 * Using barrier() here to prevent compiler from reordering
1565 * gc->irq.initialized before initialization of above
1566 * GPIO chip irq members.
1570 gc->irq.initialized = true;
1572 acpi_gpiochip_request_interrupts(gc);
1578 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1579 * @gc: the gpiochip to remove the irqchip from
1581 * This is called only from gpiochip_remove()
1583 static void gpiochip_irqchip_remove(struct gpio_chip *gc)
1585 struct irq_chip *irqchip = gc->irq.chip;
1586 unsigned int offset;
1588 acpi_gpiochip_free_interrupts(gc);
1590 if (irqchip && gc->irq.parent_handler) {
1591 struct gpio_irq_chip *irq = &gc->irq;
1594 for (i = 0; i < irq->num_parents; i++)
1595 irq_set_chained_handler_and_data(irq->parents[i],
1599 /* Remove all IRQ mappings and delete the domain */
1600 if (gc->irq.domain) {
1603 for (offset = 0; offset < gc->ngpio; offset++) {
1604 if (!gpiochip_irqchip_irq_valid(gc, offset))
1607 irq = irq_find_mapping(gc->irq.domain, offset);
1608 irq_dispose_mapping(irq);
1611 irq_domain_remove(gc->irq.domain);
1615 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
1616 irqchip->irq_request_resources = NULL;
1617 irqchip->irq_release_resources = NULL;
1619 if (irqchip->irq_enable == gpiochip_irq_enable) {
1620 irqchip->irq_enable = gc->irq.irq_enable;
1621 irqchip->irq_disable = gc->irq.irq_disable;
1624 gc->irq.irq_enable = NULL;
1625 gc->irq.irq_disable = NULL;
1626 gc->irq.chip = NULL;
1628 gpiochip_irqchip_free_valid_mask(gc);
1632 * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
1633 * @gc: the gpiochip to add the irqchip to
1634 * @domain: the irqdomain to add to the gpiochip
1636 * This function adds an IRQ domain to the gpiochip.
1638 int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
1639 struct irq_domain *domain)
1644 gc->to_irq = gpiochip_to_irq;
1645 gc->irq.domain = domain;
1649 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
1651 #else /* CONFIG_GPIOLIB_IRQCHIP */
1653 static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
1654 struct lock_class_key *lock_key,
1655 struct lock_class_key *request_key)
1659 static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
1661 static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1666 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1670 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
1673 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1676 * gpiochip_generic_request() - request the gpio function for a pin
1677 * @gc: the gpiochip owning the GPIO
1678 * @offset: the offset of the GPIO to request for GPIO function
1680 int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)
1682 #ifdef CONFIG_PINCTRL
1683 if (list_empty(&gc->gpiodev->pin_ranges))
1687 return pinctrl_gpio_request(gc->gpiodev->base + offset);
1689 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1692 * gpiochip_generic_free() - free the gpio function from a pin
1693 * @gc: the gpiochip to request the gpio function for
1694 * @offset: the offset of the GPIO to free from GPIO function
1696 void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset)
1698 #ifdef CONFIG_PINCTRL
1699 if (list_empty(&gc->gpiodev->pin_ranges))
1703 pinctrl_gpio_free(gc->gpiodev->base + offset);
1705 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1708 * gpiochip_generic_config() - apply configuration for a pin
1709 * @gc: the gpiochip owning the GPIO
1710 * @offset: the offset of the GPIO to apply the configuration
1711 * @config: the configuration to be applied
1713 int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
1714 unsigned long config)
1716 return pinctrl_gpio_set_config(gc->gpiodev->base + offset, config);
1718 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
1720 #ifdef CONFIG_PINCTRL
1723 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1724 * @gc: the gpiochip to add the range for
1725 * @pctldev: the pin controller to map to
1726 * @gpio_offset: the start offset in the current gpio_chip number space
1727 * @pin_group: name of the pin group inside the pin controller
1729 * Calling this function directly from a DeviceTree-supported
1730 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
1731 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
1732 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
1734 int gpiochip_add_pingroup_range(struct gpio_chip *gc,
1735 struct pinctrl_dev *pctldev,
1736 unsigned int gpio_offset, const char *pin_group)
1738 struct gpio_pin_range *pin_range;
1739 struct gpio_device *gdev = gc->gpiodev;
1742 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1744 chip_err(gc, "failed to allocate pin ranges\n");
1748 /* Use local offset as range ID */
1749 pin_range->range.id = gpio_offset;
1750 pin_range->range.gc = gc;
1751 pin_range->range.name = gc->label;
1752 pin_range->range.base = gdev->base + gpio_offset;
1753 pin_range->pctldev = pctldev;
1755 ret = pinctrl_get_group_pins(pctldev, pin_group,
1756 &pin_range->range.pins,
1757 &pin_range->range.npins);
1763 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1765 chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1766 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1767 pinctrl_dev_get_devname(pctldev), pin_group);
1769 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1773 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1776 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1777 * @gc: the gpiochip to add the range for
1778 * @pinctl_name: the dev_name() of the pin controller to map to
1779 * @gpio_offset: the start offset in the current gpio_chip number space
1780 * @pin_offset: the start offset in the pin controller number space
1781 * @npins: the number of pins from the offset of each pin space (GPIO and
1782 * pin controller) to accumulate in this range
1785 * 0 on success, or a negative error-code on failure.
1787 * Calling this function directly from a DeviceTree-supported
1788 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
1789 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
1790 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
1792 int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
1793 unsigned int gpio_offset, unsigned int pin_offset,
1796 struct gpio_pin_range *pin_range;
1797 struct gpio_device *gdev = gc->gpiodev;
1800 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1802 chip_err(gc, "failed to allocate pin ranges\n");
1806 /* Use local offset as range ID */
1807 pin_range->range.id = gpio_offset;
1808 pin_range->range.gc = gc;
1809 pin_range->range.name = gc->label;
1810 pin_range->range.base = gdev->base + gpio_offset;
1811 pin_range->range.pin_base = pin_offset;
1812 pin_range->range.npins = npins;
1813 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1815 if (IS_ERR(pin_range->pctldev)) {
1816 ret = PTR_ERR(pin_range->pctldev);
1817 chip_err(gc, "could not create pin range\n");
1821 chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1822 gpio_offset, gpio_offset + npins - 1,
1824 pin_offset, pin_offset + npins - 1);
1826 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1830 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1833 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1834 * @gc: the chip to remove all the mappings for
1836 void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
1838 struct gpio_pin_range *pin_range, *tmp;
1839 struct gpio_device *gdev = gc->gpiodev;
1841 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1842 list_del(&pin_range->node);
1843 pinctrl_remove_gpio_range(pin_range->pctldev,
1848 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1850 #endif /* CONFIG_PINCTRL */
1852 /* These "optional" allocation calls help prevent drivers from stomping
1853 * on each other, and help provide better diagnostics in debugfs.
1854 * They're called even less than the "set direction" calls.
1856 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
1858 struct gpio_chip *gc = desc->gdev->chip;
1860 unsigned long flags;
1864 label = kstrdup_const(label, GFP_KERNEL);
1869 spin_lock_irqsave(&gpio_lock, flags);
1871 /* NOTE: gpio_request() can be called in early boot,
1872 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1875 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1876 desc_set_label(desc, label ? : "?");
1879 goto out_free_unlock;
1883 /* gc->request may sleep */
1884 spin_unlock_irqrestore(&gpio_lock, flags);
1885 offset = gpio_chip_hwgpio(desc);
1886 if (gpiochip_line_is_valid(gc, offset))
1887 ret = gc->request(gc, offset);
1890 spin_lock_irqsave(&gpio_lock, flags);
1893 desc_set_label(desc, NULL);
1894 clear_bit(FLAG_REQUESTED, &desc->flags);
1895 goto out_free_unlock;
1898 if (gc->get_direction) {
1899 /* gc->get_direction may sleep */
1900 spin_unlock_irqrestore(&gpio_lock, flags);
1901 gpiod_get_direction(desc);
1902 spin_lock_irqsave(&gpio_lock, flags);
1904 spin_unlock_irqrestore(&gpio_lock, flags);
1908 spin_unlock_irqrestore(&gpio_lock, flags);
1914 * This descriptor validation needs to be inserted verbatim into each
1915 * function taking a descriptor, so we need to use a preprocessor
1916 * macro to avoid endless duplication. If the desc is NULL it is an
1917 * optional GPIO and calls should just bail out.
1919 static int validate_desc(const struct gpio_desc *desc, const char *func)
1924 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
1925 return PTR_ERR(desc);
1928 pr_warn("%s: invalid GPIO (no device)\n", func);
1931 if (!desc->gdev->chip) {
1932 dev_warn(&desc->gdev->dev,
1933 "%s: backing chip is gone\n", func);
1939 #define VALIDATE_DESC(desc) do { \
1940 int __valid = validate_desc(desc, __func__); \
1945 #define VALIDATE_DESC_VOID(desc) do { \
1946 int __valid = validate_desc(desc, __func__); \
1951 int gpiod_request(struct gpio_desc *desc, const char *label)
1953 int ret = -EPROBE_DEFER;
1954 struct gpio_device *gdev;
1956 VALIDATE_DESC(desc);
1959 if (try_module_get(gdev->owner)) {
1960 ret = gpiod_request_commit(desc, label);
1962 module_put(gdev->owner);
1964 get_device(&gdev->dev);
1968 gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
1973 static bool gpiod_free_commit(struct gpio_desc *desc)
1976 unsigned long flags;
1977 struct gpio_chip *gc;
1981 gpiod_unexport(desc);
1983 spin_lock_irqsave(&gpio_lock, flags);
1985 gc = desc->gdev->chip;
1986 if (gc && test_bit(FLAG_REQUESTED, &desc->flags)) {
1988 spin_unlock_irqrestore(&gpio_lock, flags);
1989 might_sleep_if(gc->can_sleep);
1990 gc->free(gc, gpio_chip_hwgpio(desc));
1991 spin_lock_irqsave(&gpio_lock, flags);
1993 kfree_const(desc->label);
1994 desc_set_label(desc, NULL);
1995 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
1996 clear_bit(FLAG_REQUESTED, &desc->flags);
1997 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
1998 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
1999 clear_bit(FLAG_PULL_UP, &desc->flags);
2000 clear_bit(FLAG_PULL_DOWN, &desc->flags);
2001 clear_bit(FLAG_BIAS_DISABLE, &desc->flags);
2002 clear_bit(FLAG_EDGE_RISING, &desc->flags);
2003 clear_bit(FLAG_EDGE_FALLING, &desc->flags);
2004 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2005 #ifdef CONFIG_OF_DYNAMIC
2008 #ifdef CONFIG_GPIO_CDEV
2009 WRITE_ONCE(desc->debounce_period_us, 0);
2014 spin_unlock_irqrestore(&gpio_lock, flags);
2015 blocking_notifier_call_chain(&desc->gdev->notifier,
2016 GPIOLINE_CHANGED_RELEASED, desc);
2021 void gpiod_free(struct gpio_desc *desc)
2023 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2024 module_put(desc->gdev->owner);
2025 put_device(&desc->gdev->dev);
2027 WARN_ON(extra_checks);
2032 * gpiochip_is_requested - return string iff signal was requested
2033 * @gc: controller managing the signal
2034 * @offset: of signal within controller's 0..(ngpio - 1) range
2036 * Returns NULL if the GPIO is not currently requested, else a string.
2037 * The string returned is the label passed to gpio_request(); if none has been
2038 * passed it is a meaningless, non-NULL constant.
2040 * This function is for use by GPIO controller drivers. The label can
2041 * help with diagnostics, and knowing that the signal is used as a GPIO
2042 * can help avoid accidentally multiplexing it to another controller.
2044 const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset)
2046 struct gpio_desc *desc;
2048 desc = gpiochip_get_desc(gc, offset);
2052 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2056 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2059 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2061 * @hwnum: hardware number of the GPIO for which to request the descriptor
2062 * @label: label for the GPIO
2063 * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2064 * specify things like line inversion semantics with the machine flags
2065 * such as GPIO_OUT_LOW
2066 * @dflags: descriptor request flags for this GPIO or 0 if default, this
2067 * can be used to specify consumer semantics such as open drain
2069 * Function allows GPIO chip drivers to request and use their own GPIO
2070 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2071 * function will not increase reference count of the GPIO chip module. This
2072 * allows the GPIO chip module to be unloaded as needed (we assume that the
2073 * GPIO chip driver handles freeing the GPIOs it has requested).
2076 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2079 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
2082 enum gpio_lookup_flags lflags,
2083 enum gpiod_flags dflags)
2085 struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
2089 chip_err(gc, "failed to get GPIO descriptor\n");
2093 ret = gpiod_request_commit(desc, label);
2095 return ERR_PTR(ret);
2097 ret = gpiod_configure_flags(desc, label, lflags, dflags);
2099 chip_err(gc, "setup of own GPIO %s failed\n", label);
2100 gpiod_free_commit(desc);
2101 return ERR_PTR(ret);
2106 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2109 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2110 * @desc: GPIO descriptor to free
2112 * Function frees the given GPIO requested previously with
2113 * gpiochip_request_own_desc().
2115 void gpiochip_free_own_desc(struct gpio_desc *desc)
2118 gpiod_free_commit(desc);
2120 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2123 * Drivers MUST set GPIO direction before making get/set calls. In
2124 * some cases this is done in early boot, before IRQs are enabled.
2126 * As a rule these aren't called more than once (except for drivers
2127 * using the open-drain emulation idiom) so these are natural places
2128 * to accumulate extra debugging checks. Note that we can't (yet)
2129 * rely on gpio_request() having been called beforehand.
2132 static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset,
2133 unsigned long config)
2135 if (!gc->set_config)
2138 return gc->set_config(gc, offset, config);
2141 static int gpio_set_config_with_argument(struct gpio_desc *desc,
2142 enum pin_config_param mode,
2145 struct gpio_chip *gc = desc->gdev->chip;
2146 unsigned long config;
2148 config = pinconf_to_config_packed(mode, argument);
2149 return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
2152 static int gpio_set_config_with_argument_optional(struct gpio_desc *desc,
2153 enum pin_config_param mode,
2156 struct device *dev = &desc->gdev->dev;
2157 int gpio = gpio_chip_hwgpio(desc);
2160 ret = gpio_set_config_with_argument(desc, mode, argument);
2161 if (ret != -ENOTSUPP)
2165 case PIN_CONFIG_PERSIST_STATE:
2166 dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio);
2175 static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
2177 return gpio_set_config_with_argument(desc, mode, 0);
2180 static int gpio_set_bias(struct gpio_desc *desc)
2182 enum pin_config_param bias;
2185 if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
2186 bias = PIN_CONFIG_BIAS_DISABLE;
2187 else if (test_bit(FLAG_PULL_UP, &desc->flags))
2188 bias = PIN_CONFIG_BIAS_PULL_UP;
2189 else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
2190 bias = PIN_CONFIG_BIAS_PULL_DOWN;
2195 case PIN_CONFIG_BIAS_PULL_DOWN:
2196 case PIN_CONFIG_BIAS_PULL_UP:
2205 return gpio_set_config_with_argument_optional(desc, bias, arg);
2209 * gpio_set_debounce_timeout() - Set debounce timeout
2210 * @desc: GPIO descriptor to set the debounce timeout
2211 * @debounce: Debounce timeout in microseconds
2213 * The function calls the certain GPIO driver to set debounce timeout
2216 * Returns 0 on success, or negative error code otherwise.
2218 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
2220 return gpio_set_config_with_argument_optional(desc,
2221 PIN_CONFIG_INPUT_DEBOUNCE,
2226 * gpiod_direction_input - set the GPIO direction to input
2227 * @desc: GPIO to set to input
2229 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2230 * be called safely on it.
2232 * Return 0 in case of success, else an error code.
2234 int gpiod_direction_input(struct gpio_desc *desc)
2236 struct gpio_chip *gc;
2239 VALIDATE_DESC(desc);
2240 gc = desc->gdev->chip;
2243 * It is legal to have no .get() and .direction_input() specified if
2244 * the chip is output-only, but you can't specify .direction_input()
2245 * and not support the .get() operation, that doesn't make sense.
2247 if (!gc->get && gc->direction_input) {
2249 "%s: missing get() but have direction_input()\n",
2255 * If we have a .direction_input() callback, things are simple,
2256 * just call it. Else we are some input-only chip so try to check the
2257 * direction (if .get_direction() is supported) else we silently
2258 * assume we are in input mode after this.
2260 if (gc->direction_input) {
2261 ret = gc->direction_input(gc, gpio_chip_hwgpio(desc));
2262 } else if (gc->get_direction &&
2263 (gc->get_direction(gc, gpio_chip_hwgpio(desc)) != 1)) {
2265 "%s: missing direction_input() operation and line is output\n",
2270 clear_bit(FLAG_IS_OUT, &desc->flags);
2271 ret = gpio_set_bias(desc);
2274 trace_gpio_direction(desc_to_gpio(desc), 1, ret);
2278 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2280 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2282 struct gpio_chip *gc = desc->gdev->chip;
2287 * It's OK not to specify .direction_output() if the gpiochip is
2288 * output-only, but if there is then not even a .set() operation it
2289 * is pretty tricky to drive the output line.
2291 if (!gc->set && !gc->direction_output) {
2293 "%s: missing set() and direction_output() operations\n",
2298 if (gc->direction_output) {
2299 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2301 /* Check that we are in output mode if we can */
2302 if (gc->get_direction &&
2303 gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
2305 "%s: missing direction_output() operation\n",
2310 * If we can't actively set the direction, we are some
2311 * output-only chip, so just drive the output as desired.
2313 gc->set(gc, gpio_chip_hwgpio(desc), val);
2317 set_bit(FLAG_IS_OUT, &desc->flags);
2318 trace_gpio_value(desc_to_gpio(desc), 0, val);
2319 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2324 * gpiod_direction_output_raw - set the GPIO direction to output
2325 * @desc: GPIO to set to output
2326 * @value: initial output value of the GPIO
2328 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2329 * be called safely on it. The initial value of the output must be specified
2330 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2332 * Return 0 in case of success, else an error code.
2334 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2336 VALIDATE_DESC(desc);
2337 return gpiod_direction_output_raw_commit(desc, value);
2339 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2342 * gpiod_direction_output - set the GPIO direction to output
2343 * @desc: GPIO to set to output
2344 * @value: initial output value of the GPIO
2346 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2347 * be called safely on it. The initial value of the output must be specified
2348 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2351 * Return 0 in case of success, else an error code.
2353 int gpiod_direction_output(struct gpio_desc *desc, int value)
2357 VALIDATE_DESC(desc);
2358 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2363 /* GPIOs used for enabled IRQs shall not be set as output */
2364 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
2365 test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
2367 "%s: tried to set a GPIO tied to an IRQ as output\n",
2372 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2373 /* First see if we can enable open drain in hardware */
2374 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
2376 goto set_output_value;
2377 /* Emulate open drain by not actively driving the line high */
2379 ret = gpiod_direction_input(desc);
2380 goto set_output_flag;
2383 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2384 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
2386 goto set_output_value;
2387 /* Emulate open source by not actively driving the line low */
2389 ret = gpiod_direction_input(desc);
2390 goto set_output_flag;
2393 gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
2397 ret = gpio_set_bias(desc);
2400 return gpiod_direction_output_raw_commit(desc, value);
2404 * When emulating open-source or open-drain functionalities by not
2405 * actively driving the line (setting mode to input) we still need to
2406 * set the IS_OUT flag or otherwise we won't be able to set the line
2410 set_bit(FLAG_IS_OUT, &desc->flags);
2413 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2416 * gpiod_set_config - sets @config for a GPIO
2417 * @desc: descriptor of the GPIO for which to set the configuration
2418 * @config: Same packed config format as generic pinconf
2421 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2424 int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
2426 struct gpio_chip *gc;
2428 VALIDATE_DESC(desc);
2429 gc = desc->gdev->chip;
2431 return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
2433 EXPORT_SYMBOL_GPL(gpiod_set_config);
2436 * gpiod_set_debounce - sets @debounce time for a GPIO
2437 * @desc: descriptor of the GPIO for which to set debounce time
2438 * @debounce: debounce time in microseconds
2441 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2444 int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce)
2446 unsigned long config;
2448 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2449 return gpiod_set_config(desc, config);
2451 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2454 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2455 * @desc: descriptor of the GPIO for which to configure persistence
2456 * @transitory: True to lose state on suspend or reset, false for persistence
2459 * 0 on success, otherwise a negative error code.
2461 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2463 VALIDATE_DESC(desc);
2465 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2466 * persistence state.
2468 assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
2470 /* If the driver supports it, set the persistence state now */
2471 return gpio_set_config_with_argument_optional(desc,
2472 PIN_CONFIG_PERSIST_STATE,
2475 EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2478 * gpiod_is_active_low - test whether a GPIO is active-low or not
2479 * @desc: the gpio descriptor to test
2481 * Returns 1 if the GPIO is active-low, 0 otherwise.
2483 int gpiod_is_active_low(const struct gpio_desc *desc)
2485 VALIDATE_DESC(desc);
2486 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2488 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2491 * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
2492 * @desc: the gpio descriptor to change
2494 void gpiod_toggle_active_low(struct gpio_desc *desc)
2496 VALIDATE_DESC_VOID(desc);
2497 change_bit(FLAG_ACTIVE_LOW, &desc->flags);
2499 EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
2501 /* I/O calls are only valid after configuration completed; the relevant
2502 * "is this a valid GPIO" error checks should already have been done.
2504 * "Get" operations are often inlinable as reading a pin value register,
2505 * and masking the relevant bit in that register.
2507 * When "set" operations are inlinable, they involve writing that mask to
2508 * one register to set a low value, or a different register to set it high.
2509 * Otherwise locking is needed, so there may be little value to inlining.
2511 *------------------------------------------------------------------------
2513 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2514 * have requested the GPIO. That can include implicit requesting by
2515 * a direction setting call. Marking a gpio as requested locks its chip
2516 * in memory, guaranteeing that these table lookups need no more locking
2517 * and that gpiochip_remove() will fail.
2519 * REVISIT when debugging, consider adding some instrumentation to ensure
2520 * that the GPIO was actually requested.
2523 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2525 struct gpio_chip *gc;
2529 gc = desc->gdev->chip;
2530 offset = gpio_chip_hwgpio(desc);
2531 value = gc->get ? gc->get(gc, offset) : -EIO;
2532 value = value < 0 ? value : !!value;
2533 trace_gpio_value(desc_to_gpio(desc), 1, value);
2537 static int gpio_chip_get_multiple(struct gpio_chip *gc,
2538 unsigned long *mask, unsigned long *bits)
2540 if (gc->get_multiple) {
2541 return gc->get_multiple(gc, mask, bits);
2542 } else if (gc->get) {
2545 for_each_set_bit(i, mask, gc->ngpio) {
2546 value = gc->get(gc, i);
2549 __assign_bit(i, bits, value);
2556 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2557 unsigned int array_size,
2558 struct gpio_desc **desc_array,
2559 struct gpio_array *array_info,
2560 unsigned long *value_bitmap)
2565 * Validate array_info against desc_array and its size.
2566 * It should immediately follow desc_array if both
2567 * have been obtained from the same gpiod_get_array() call.
2569 if (array_info && array_info->desc == desc_array &&
2570 array_size <= array_info->size &&
2571 (void *)array_info == desc_array + array_info->size) {
2573 WARN_ON(array_info->chip->can_sleep);
2575 ret = gpio_chip_get_multiple(array_info->chip,
2576 array_info->get_mask,
2581 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2582 bitmap_xor(value_bitmap, value_bitmap,
2583 array_info->invert_mask, array_size);
2585 i = find_first_zero_bit(array_info->get_mask, array_size);
2586 if (i == array_size)
2592 while (i < array_size) {
2593 struct gpio_chip *gc = desc_array[i]->gdev->chip;
2594 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
2595 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
2596 unsigned long *mask, *bits;
2599 if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
2600 mask = fastpath_mask;
2601 bits = fastpath_bits;
2603 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
2605 mask = bitmap_alloc(gc->ngpio, flags);
2609 bits = bitmap_alloc(gc->ngpio, flags);
2616 bitmap_zero(mask, gc->ngpio);
2619 WARN_ON(gc->can_sleep);
2621 /* collect all inputs belonging to the same chip */
2624 const struct gpio_desc *desc = desc_array[i];
2625 int hwgpio = gpio_chip_hwgpio(desc);
2627 __set_bit(hwgpio, mask);
2631 i = find_next_zero_bit(array_info->get_mask,
2633 } while ((i < array_size) &&
2634 (desc_array[i]->gdev->chip == gc));
2636 ret = gpio_chip_get_multiple(gc, mask, bits);
2638 if (mask != fastpath_mask)
2640 if (bits != fastpath_bits)
2645 for (j = first; j < i; ) {
2646 const struct gpio_desc *desc = desc_array[j];
2647 int hwgpio = gpio_chip_hwgpio(desc);
2648 int value = test_bit(hwgpio, bits);
2650 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2652 __assign_bit(j, value_bitmap, value);
2653 trace_gpio_value(desc_to_gpio(desc), 1, value);
2657 j = find_next_zero_bit(array_info->get_mask, i,
2661 if (mask != fastpath_mask)
2663 if (bits != fastpath_bits)
2670 * gpiod_get_raw_value() - return a gpio's raw value
2671 * @desc: gpio whose value will be returned
2673 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2674 * its ACTIVE_LOW status, or negative errno on failure.
2676 * This function can be called from contexts where we cannot sleep, and will
2677 * complain if the GPIO chip functions potentially sleep.
2679 int gpiod_get_raw_value(const struct gpio_desc *desc)
2681 VALIDATE_DESC(desc);
2682 /* Should be using gpiod_get_raw_value_cansleep() */
2683 WARN_ON(desc->gdev->chip->can_sleep);
2684 return gpiod_get_raw_value_commit(desc);
2686 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2689 * gpiod_get_value() - return a gpio's value
2690 * @desc: gpio whose value will be returned
2692 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2693 * account, or negative errno on failure.
2695 * This function can be called from contexts where we cannot sleep, and will
2696 * complain if the GPIO chip functions potentially sleep.
2698 int gpiod_get_value(const struct gpio_desc *desc)
2702 VALIDATE_DESC(desc);
2703 /* Should be using gpiod_get_value_cansleep() */
2704 WARN_ON(desc->gdev->chip->can_sleep);
2706 value = gpiod_get_raw_value_commit(desc);
2710 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2715 EXPORT_SYMBOL_GPL(gpiod_get_value);
2718 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
2719 * @array_size: number of elements in the descriptor array / value bitmap
2720 * @desc_array: array of GPIO descriptors whose values will be read
2721 * @array_info: information on applicability of fast bitmap processing path
2722 * @value_bitmap: bitmap to store the read values
2724 * Read the raw values of the GPIOs, i.e. the values of the physical lines
2725 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
2726 * else an error code.
2728 * This function can be called from contexts where we cannot sleep,
2729 * and it will complain if the GPIO chip functions potentially sleep.
2731 int gpiod_get_raw_array_value(unsigned int array_size,
2732 struct gpio_desc **desc_array,
2733 struct gpio_array *array_info,
2734 unsigned long *value_bitmap)
2738 return gpiod_get_array_value_complex(true, false, array_size,
2739 desc_array, array_info,
2742 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
2745 * gpiod_get_array_value() - read values from an array of GPIOs
2746 * @array_size: number of elements in the descriptor array / value bitmap
2747 * @desc_array: array of GPIO descriptors whose values will be read
2748 * @array_info: information on applicability of fast bitmap processing path
2749 * @value_bitmap: bitmap to store the read values
2751 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2752 * into account. Return 0 in case of success, else an error code.
2754 * This function can be called from contexts where we cannot sleep,
2755 * and it will complain if the GPIO chip functions potentially sleep.
2757 int gpiod_get_array_value(unsigned int array_size,
2758 struct gpio_desc **desc_array,
2759 struct gpio_array *array_info,
2760 unsigned long *value_bitmap)
2764 return gpiod_get_array_value_complex(false, false, array_size,
2765 desc_array, array_info,
2768 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
2771 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
2772 * @desc: gpio descriptor whose state need to be set.
2773 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2775 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
2778 struct gpio_chip *gc = desc->gdev->chip;
2779 int offset = gpio_chip_hwgpio(desc);
2782 ret = gc->direction_input(gc, offset);
2784 ret = gc->direction_output(gc, offset, 0);
2786 set_bit(FLAG_IS_OUT, &desc->flags);
2788 trace_gpio_direction(desc_to_gpio(desc), value, ret);
2791 "%s: Error in set_value for open drain err %d\n",
2796 * _gpio_set_open_source_value() - Set the open source gpio's value.
2797 * @desc: gpio descriptor whose state need to be set.
2798 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2800 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
2803 struct gpio_chip *gc = desc->gdev->chip;
2804 int offset = gpio_chip_hwgpio(desc);
2807 ret = gc->direction_output(gc, offset, 1);
2809 set_bit(FLAG_IS_OUT, &desc->flags);
2811 ret = gc->direction_input(gc, offset);
2813 trace_gpio_direction(desc_to_gpio(desc), !value, ret);
2816 "%s: Error in set_value for open source err %d\n",
2820 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
2822 struct gpio_chip *gc;
2824 gc = desc->gdev->chip;
2825 trace_gpio_value(desc_to_gpio(desc), 0, value);
2826 gc->set(gc, gpio_chip_hwgpio(desc), value);
2830 * set multiple outputs on the same chip;
2831 * use the chip's set_multiple function if available;
2832 * otherwise set the outputs sequentially;
2833 * @chip: the GPIO chip we operate on
2834 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2835 * defines which outputs are to be changed
2836 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2837 * defines the values the outputs specified by mask are to be set to
2839 static void gpio_chip_set_multiple(struct gpio_chip *gc,
2840 unsigned long *mask, unsigned long *bits)
2842 if (gc->set_multiple) {
2843 gc->set_multiple(gc, mask, bits);
2847 /* set outputs if the corresponding mask bit is set */
2848 for_each_set_bit(i, mask, gc->ngpio)
2849 gc->set(gc, i, test_bit(i, bits));
2853 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
2854 unsigned int array_size,
2855 struct gpio_desc **desc_array,
2856 struct gpio_array *array_info,
2857 unsigned long *value_bitmap)
2862 * Validate array_info against desc_array and its size.
2863 * It should immediately follow desc_array if both
2864 * have been obtained from the same gpiod_get_array() call.
2866 if (array_info && array_info->desc == desc_array &&
2867 array_size <= array_info->size &&
2868 (void *)array_info == desc_array + array_info->size) {
2870 WARN_ON(array_info->chip->can_sleep);
2872 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2873 bitmap_xor(value_bitmap, value_bitmap,
2874 array_info->invert_mask, array_size);
2876 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
2879 i = find_first_zero_bit(array_info->set_mask, array_size);
2880 if (i == array_size)
2886 while (i < array_size) {
2887 struct gpio_chip *gc = desc_array[i]->gdev->chip;
2888 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
2889 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
2890 unsigned long *mask, *bits;
2893 if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
2894 mask = fastpath_mask;
2895 bits = fastpath_bits;
2897 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
2899 mask = bitmap_alloc(gc->ngpio, flags);
2903 bits = bitmap_alloc(gc->ngpio, flags);
2910 bitmap_zero(mask, gc->ngpio);
2913 WARN_ON(gc->can_sleep);
2916 struct gpio_desc *desc = desc_array[i];
2917 int hwgpio = gpio_chip_hwgpio(desc);
2918 int value = test_bit(i, value_bitmap);
2921 * Pins applicable for fast input but not for
2922 * fast output processing may have been already
2923 * inverted inside the fast path, skip them.
2925 if (!raw && !(array_info &&
2926 test_bit(i, array_info->invert_mask)) &&
2927 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2929 trace_gpio_value(desc_to_gpio(desc), 0, value);
2931 * collect all normal outputs belonging to the same chip
2932 * open drain and open source outputs are set individually
2934 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
2935 gpio_set_open_drain_value_commit(desc, value);
2936 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
2937 gpio_set_open_source_value_commit(desc, value);
2939 __set_bit(hwgpio, mask);
2940 __assign_bit(hwgpio, bits, value);
2946 i = find_next_zero_bit(array_info->set_mask,
2948 } while ((i < array_size) &&
2949 (desc_array[i]->gdev->chip == gc));
2950 /* push collected bits to outputs */
2952 gpio_chip_set_multiple(gc, mask, bits);
2954 if (mask != fastpath_mask)
2956 if (bits != fastpath_bits)
2963 * gpiod_set_raw_value() - assign a gpio's raw value
2964 * @desc: gpio whose value will be assigned
2965 * @value: value to assign
2967 * Set the raw value of the GPIO, i.e. the value of its physical line without
2968 * regard for its ACTIVE_LOW status.
2970 * This function can be called from contexts where we cannot sleep, and will
2971 * complain if the GPIO chip functions potentially sleep.
2973 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
2975 VALIDATE_DESC_VOID(desc);
2976 /* Should be using gpiod_set_raw_value_cansleep() */
2977 WARN_ON(desc->gdev->chip->can_sleep);
2978 gpiod_set_raw_value_commit(desc, value);
2980 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
2983 * gpiod_set_value_nocheck() - set a GPIO line value without checking
2984 * @desc: the descriptor to set the value on
2985 * @value: value to set
2987 * This sets the value of a GPIO line backing a descriptor, applying
2988 * different semantic quirks like active low and open drain/source
2991 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
2993 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2995 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
2996 gpio_set_open_drain_value_commit(desc, value);
2997 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
2998 gpio_set_open_source_value_commit(desc, value);
3000 gpiod_set_raw_value_commit(desc, value);
3004 * gpiod_set_value() - assign a gpio's value
3005 * @desc: gpio whose value will be assigned
3006 * @value: value to assign
3008 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3009 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3011 * This function can be called from contexts where we cannot sleep, and will
3012 * complain if the GPIO chip functions potentially sleep.
3014 void gpiod_set_value(struct gpio_desc *desc, int value)
3016 VALIDATE_DESC_VOID(desc);
3017 /* Should be using gpiod_set_value_cansleep() */
3018 WARN_ON(desc->gdev->chip->can_sleep);
3019 gpiod_set_value_nocheck(desc, value);
3021 EXPORT_SYMBOL_GPL(gpiod_set_value);
3024 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3025 * @array_size: number of elements in the descriptor array / value bitmap
3026 * @desc_array: array of GPIO descriptors whose values will be assigned
3027 * @array_info: information on applicability of fast bitmap processing path
3028 * @value_bitmap: bitmap of values to assign
3030 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3031 * without regard for their ACTIVE_LOW status.
3033 * This function can be called from contexts where we cannot sleep, and will
3034 * complain if the GPIO chip functions potentially sleep.
3036 int gpiod_set_raw_array_value(unsigned int array_size,
3037 struct gpio_desc **desc_array,
3038 struct gpio_array *array_info,
3039 unsigned long *value_bitmap)
3043 return gpiod_set_array_value_complex(true, false, array_size,
3044 desc_array, array_info, value_bitmap);
3046 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3049 * gpiod_set_array_value() - assign values to an array of GPIOs
3050 * @array_size: number of elements in the descriptor array / value bitmap
3051 * @desc_array: array of GPIO descriptors whose values will be assigned
3052 * @array_info: information on applicability of fast bitmap processing path
3053 * @value_bitmap: bitmap of values to assign
3055 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3058 * This function can be called from contexts where we cannot sleep, and will
3059 * complain if the GPIO chip functions potentially sleep.
3061 int gpiod_set_array_value(unsigned int array_size,
3062 struct gpio_desc **desc_array,
3063 struct gpio_array *array_info,
3064 unsigned long *value_bitmap)
3068 return gpiod_set_array_value_complex(false, false, array_size,
3069 desc_array, array_info,
3072 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3075 * gpiod_cansleep() - report whether gpio value access may sleep
3076 * @desc: gpio to check
3079 int gpiod_cansleep(const struct gpio_desc *desc)
3081 VALIDATE_DESC(desc);
3082 return desc->gdev->chip->can_sleep;
3084 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3087 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3088 * @desc: gpio to set the consumer name on
3089 * @name: the new consumer name
3091 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3093 VALIDATE_DESC(desc);
3095 name = kstrdup_const(name, GFP_KERNEL);
3100 kfree_const(desc->label);
3101 desc_set_label(desc, name);
3105 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3108 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3109 * @desc: gpio whose IRQ will be returned (already requested)
3111 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3114 int gpiod_to_irq(const struct gpio_desc *desc)
3116 struct gpio_chip *gc;
3120 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3121 * requires this function to not return zero on an invalid descriptor
3122 * but rather a negative error number.
3124 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3127 gc = desc->gdev->chip;
3128 offset = gpio_chip_hwgpio(desc);
3130 int retirq = gc->to_irq(gc, offset);
3132 /* Zero means NO_IRQ */
3138 #ifdef CONFIG_GPIOLIB_IRQCHIP
3141 * Avoid race condition with other code, which tries to lookup
3142 * an IRQ before the irqchip has been properly registered,
3143 * i.e. while gpiochip is still being brought up.
3145 return -EPROBE_DEFER;
3150 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3153 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3154 * @gc: the chip the GPIO to lock belongs to
3155 * @offset: the offset of the GPIO to lock as IRQ
3157 * This is used directly by GPIO drivers that want to lock down
3158 * a certain GPIO line to be used for IRQs.
3160 int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
3162 struct gpio_desc *desc;
3164 desc = gpiochip_get_desc(gc, offset);
3166 return PTR_ERR(desc);
3169 * If it's fast: flush the direction setting if something changed
3172 if (!gc->can_sleep && gc->get_direction) {
3173 int dir = gpiod_get_direction(desc);
3176 chip_err(gc, "%s: cannot get GPIO direction\n",
3182 /* To be valid for IRQ the line needs to be input or open drain */
3183 if (test_bit(FLAG_IS_OUT, &desc->flags) &&
3184 !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
3186 "%s: tried to flag a GPIO set as output for IRQ\n",
3191 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3192 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3195 * If the consumer has not set up a label (such as when the
3196 * IRQ is referenced from .to_irq()) we set up a label here
3197 * so it is clear this is used as an interrupt.
3200 desc_set_label(desc, "interrupt");
3204 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3207 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3208 * @gc: the chip the GPIO to lock belongs to
3209 * @offset: the offset of the GPIO to lock as IRQ
3211 * This is used directly by GPIO drivers that want to indicate
3212 * that a certain GPIO is no longer used exclusively for IRQ.
3214 void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
3216 struct gpio_desc *desc;
3218 desc = gpiochip_get_desc(gc, offset);
3222 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3223 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3225 /* If we only had this marking, erase it */
3226 if (desc->label && !strcmp(desc->label, "interrupt"))
3227 desc_set_label(desc, NULL);
3229 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3231 void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
3233 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3235 if (!IS_ERR(desc) &&
3236 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3237 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3239 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3241 void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
3243 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3245 if (!IS_ERR(desc) &&
3246 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3248 * We must not be output when using IRQ UNLESS we are
3251 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
3252 !test_bit(FLAG_OPEN_DRAIN, &desc->flags));
3253 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3256 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3258 bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
3260 if (offset >= gc->ngpio)
3263 return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
3265 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3267 int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
3271 if (!try_module_get(gc->gpiodev->owner))
3274 ret = gpiochip_lock_as_irq(gc, offset);
3276 chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
3277 module_put(gc->gpiodev->owner);
3282 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3284 void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
3286 gpiochip_unlock_as_irq(gc, offset);
3287 module_put(gc->gpiodev->owner);
3289 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3291 bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
3293 if (offset >= gc->ngpio)
3296 return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
3298 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3300 bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
3302 if (offset >= gc->ngpio)
3305 return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
3307 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3309 bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
3311 if (offset >= gc->ngpio)
3314 return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
3316 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3319 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3320 * @desc: gpio whose value will be returned
3322 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3323 * its ACTIVE_LOW status, or negative errno on failure.
3325 * This function is to be called from contexts that can sleep.
3327 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3329 might_sleep_if(extra_checks);
3330 VALIDATE_DESC(desc);
3331 return gpiod_get_raw_value_commit(desc);
3333 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3336 * gpiod_get_value_cansleep() - return a gpio's value
3337 * @desc: gpio whose value will be returned
3339 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3340 * account, or negative errno on failure.
3342 * This function is to be called from contexts that can sleep.
3344 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3348 might_sleep_if(extra_checks);
3349 VALIDATE_DESC(desc);
3350 value = gpiod_get_raw_value_commit(desc);
3354 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3359 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3362 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3363 * @array_size: number of elements in the descriptor array / value bitmap
3364 * @desc_array: array of GPIO descriptors whose values will be read
3365 * @array_info: information on applicability of fast bitmap processing path
3366 * @value_bitmap: bitmap to store the read values
3368 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3369 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3370 * else an error code.
3372 * This function is to be called from contexts that can sleep.
3374 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3375 struct gpio_desc **desc_array,
3376 struct gpio_array *array_info,
3377 unsigned long *value_bitmap)
3379 might_sleep_if(extra_checks);
3382 return gpiod_get_array_value_complex(true, true, array_size,
3383 desc_array, array_info,
3386 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3389 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3390 * @array_size: number of elements in the descriptor array / value bitmap
3391 * @desc_array: array of GPIO descriptors whose values will be read
3392 * @array_info: information on applicability of fast bitmap processing path
3393 * @value_bitmap: bitmap to store the read values
3395 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3396 * into account. Return 0 in case of success, else an error code.
3398 * This function is to be called from contexts that can sleep.
3400 int gpiod_get_array_value_cansleep(unsigned int array_size,
3401 struct gpio_desc **desc_array,
3402 struct gpio_array *array_info,
3403 unsigned long *value_bitmap)
3405 might_sleep_if(extra_checks);
3408 return gpiod_get_array_value_complex(false, true, array_size,
3409 desc_array, array_info,
3412 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3415 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3416 * @desc: gpio whose value will be assigned
3417 * @value: value to assign
3419 * Set the raw value of the GPIO, i.e. the value of its physical line without
3420 * regard for its ACTIVE_LOW status.
3422 * This function is to be called from contexts that can sleep.
3424 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3426 might_sleep_if(extra_checks);
3427 VALIDATE_DESC_VOID(desc);
3428 gpiod_set_raw_value_commit(desc, value);
3430 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3433 * gpiod_set_value_cansleep() - assign a gpio's value
3434 * @desc: gpio whose value will be assigned
3435 * @value: value to assign
3437 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3440 * This function is to be called from contexts that can sleep.
3442 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3444 might_sleep_if(extra_checks);
3445 VALIDATE_DESC_VOID(desc);
3446 gpiod_set_value_nocheck(desc, value);
3448 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3451 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3452 * @array_size: number of elements in the descriptor array / value bitmap
3453 * @desc_array: array of GPIO descriptors whose values will be assigned
3454 * @array_info: information on applicability of fast bitmap processing path
3455 * @value_bitmap: bitmap of values to assign
3457 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3458 * without regard for their ACTIVE_LOW status.
3460 * This function is to be called from contexts that can sleep.
3462 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3463 struct gpio_desc **desc_array,
3464 struct gpio_array *array_info,
3465 unsigned long *value_bitmap)
3467 might_sleep_if(extra_checks);
3470 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3471 array_info, value_bitmap);
3473 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3476 * gpiod_add_lookup_tables() - register GPIO device consumers
3477 * @tables: list of tables of consumers to register
3478 * @n: number of tables in the list
3480 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3484 mutex_lock(&gpio_lookup_lock);
3486 for (i = 0; i < n; i++)
3487 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3489 mutex_unlock(&gpio_lookup_lock);
3493 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3494 * @array_size: number of elements in the descriptor array / value bitmap
3495 * @desc_array: array of GPIO descriptors whose values will be assigned
3496 * @array_info: information on applicability of fast bitmap processing path
3497 * @value_bitmap: bitmap of values to assign
3499 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3502 * This function is to be called from contexts that can sleep.
3504 int gpiod_set_array_value_cansleep(unsigned int array_size,
3505 struct gpio_desc **desc_array,
3506 struct gpio_array *array_info,
3507 unsigned long *value_bitmap)
3509 might_sleep_if(extra_checks);
3512 return gpiod_set_array_value_complex(false, true, array_size,
3513 desc_array, array_info,
3516 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3519 * gpiod_add_lookup_table() - register GPIO device consumers
3520 * @table: table of consumers to register
3522 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3524 mutex_lock(&gpio_lookup_lock);
3526 list_add_tail(&table->list, &gpio_lookup_list);
3528 mutex_unlock(&gpio_lookup_lock);
3530 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3533 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3534 * @table: table of consumers to unregister
3536 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3538 /* Nothing to remove */
3542 mutex_lock(&gpio_lookup_lock);
3544 list_del(&table->list);
3546 mutex_unlock(&gpio_lookup_lock);
3548 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3551 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
3552 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
3554 void gpiod_add_hogs(struct gpiod_hog *hogs)
3556 struct gpio_chip *gc;
3557 struct gpiod_hog *hog;
3559 mutex_lock(&gpio_machine_hogs_mutex);
3561 for (hog = &hogs[0]; hog->chip_label; hog++) {
3562 list_add_tail(&hog->list, &gpio_machine_hogs);
3565 * The chip may have been registered earlier, so check if it
3566 * exists and, if so, try to hog the line now.
3568 gc = find_chip_by_name(hog->chip_label);
3570 gpiochip_machine_hog(gc, hog);
3573 mutex_unlock(&gpio_machine_hogs_mutex);
3575 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
3577 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3579 const char *dev_id = dev ? dev_name(dev) : NULL;
3580 struct gpiod_lookup_table *table;
3582 mutex_lock(&gpio_lookup_lock);
3584 list_for_each_entry(table, &gpio_lookup_list, list) {
3585 if (table->dev_id && dev_id) {
3587 * Valid strings on both ends, must be identical to have
3590 if (!strcmp(table->dev_id, dev_id))
3594 * One of the pointers is NULL, so both must be to have
3597 if (dev_id == table->dev_id)
3604 mutex_unlock(&gpio_lookup_lock);
3608 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3609 unsigned int idx, unsigned long *flags)
3611 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3612 struct gpiod_lookup_table *table;
3613 struct gpiod_lookup *p;
3615 table = gpiod_find_lookup_table(dev);
3619 for (p = &table->table[0]; p->key; p++) {
3620 struct gpio_chip *gc;
3622 /* idx must always match exactly */
3626 /* If the lookup entry has a con_id, require exact match */
3627 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3630 if (p->chip_hwnum == U16_MAX) {
3631 desc = gpio_name_to_desc(p->key);
3637 dev_warn(dev, "cannot find GPIO line %s, deferring\n",
3639 return ERR_PTR(-EPROBE_DEFER);
3642 gc = find_chip_by_name(p->key);
3646 * As the lookup table indicates a chip with
3647 * p->key should exist, assume it may
3648 * still appear later and let the interested
3649 * consumer be probed again or let the Deferred
3650 * Probe infrastructure handle the error.
3652 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
3654 return ERR_PTR(-EPROBE_DEFER);
3657 if (gc->ngpio <= p->chip_hwnum) {
3659 "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
3660 idx, p->chip_hwnum, gc->ngpio - 1,
3662 return ERR_PTR(-EINVAL);
3665 desc = gpiochip_get_desc(gc, p->chip_hwnum);
3674 static int platform_gpio_count(struct device *dev, const char *con_id)
3676 struct gpiod_lookup_table *table;
3677 struct gpiod_lookup *p;
3678 unsigned int count = 0;
3680 table = gpiod_find_lookup_table(dev);
3684 for (p = &table->table[0]; p->key; p++) {
3685 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3686 (!con_id && !p->con_id))
3696 * fwnode_gpiod_get_index - obtain a GPIO from firmware node
3697 * @fwnode: handle of the firmware node
3698 * @con_id: function within the GPIO consumer
3699 * @index: index of the GPIO to obtain for the consumer
3700 * @flags: GPIO initialization flags
3701 * @label: label to attach to the requested GPIO
3703 * This function can be used for drivers that get their configuration
3704 * from opaque firmware.
3706 * The function properly finds the corresponding GPIO using whatever is the
3707 * underlying firmware interface and then makes sure that the GPIO
3708 * descriptor is requested before it is returned to the caller.
3711 * On successful request the GPIO pin is configured in accordance with
3714 * In case of error an ERR_PTR() is returned.
3716 struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
3717 const char *con_id, int index,
3718 enum gpiod_flags flags,
3721 struct gpio_desc *desc;
3722 char prop_name[32]; /* 32 is max size of property name */
3725 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3727 snprintf(prop_name, sizeof(prop_name), "%s-%s",
3728 con_id, gpio_suffixes[i]);
3730 snprintf(prop_name, sizeof(prop_name), "%s",
3733 desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
3735 if (!gpiod_not_found(desc))
3741 EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
3744 * gpiod_count - return the number of GPIOs associated with a device / function
3745 * or -ENOENT if no GPIO has been assigned to the requested function
3746 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3747 * @con_id: function within the GPIO consumer
3749 int gpiod_count(struct device *dev, const char *con_id)
3751 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
3752 int count = -ENOENT;
3754 if (is_of_node(fwnode))
3755 count = of_gpio_get_count(dev, con_id);
3756 else if (is_acpi_node(fwnode))
3757 count = acpi_gpio_count(dev, con_id);
3760 count = platform_gpio_count(dev, con_id);
3764 EXPORT_SYMBOL_GPL(gpiod_count);
3767 * gpiod_get - obtain a GPIO for a given GPIO function
3768 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3769 * @con_id: function within the GPIO consumer
3770 * @flags: optional GPIO initialization flags
3772 * Return the GPIO descriptor corresponding to the function con_id of device
3773 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3774 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3776 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3777 enum gpiod_flags flags)
3779 return gpiod_get_index(dev, con_id, 0, flags);
3781 EXPORT_SYMBOL_GPL(gpiod_get);
3784 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3785 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3786 * @con_id: function within the GPIO consumer
3787 * @flags: optional GPIO initialization flags
3789 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3790 * the requested function it will return NULL. This is convenient for drivers
3791 * that need to handle optional GPIOs.
3793 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3795 enum gpiod_flags flags)
3797 return gpiod_get_index_optional(dev, con_id, 0, flags);
3799 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3803 * gpiod_configure_flags - helper function to configure a given GPIO
3804 * @desc: gpio whose value will be assigned
3805 * @con_id: function within the GPIO consumer
3806 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
3807 * of_find_gpio() or of_get_gpio_hog()
3808 * @dflags: gpiod_flags - optional GPIO initialization flags
3810 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3811 * requested function and/or index, or another IS_ERR() code if an error
3812 * occurred while trying to acquire the GPIO.
3814 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3815 unsigned long lflags, enum gpiod_flags dflags)
3819 if (lflags & GPIO_ACTIVE_LOW)
3820 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3822 if (lflags & GPIO_OPEN_DRAIN)
3823 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3824 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
3826 * This enforces open drain mode from the consumer side.
3827 * This is necessary for some busses like I2C, but the lookup
3828 * should *REALLY* have specified them as open drain in the
3829 * first place, so print a little warning here.
3831 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3833 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
3836 if (lflags & GPIO_OPEN_SOURCE)
3837 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3839 if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
3841 "both pull-up and pull-down enabled, invalid configuration\n");
3845 if (lflags & GPIO_PULL_UP)
3846 set_bit(FLAG_PULL_UP, &desc->flags);
3847 else if (lflags & GPIO_PULL_DOWN)
3848 set_bit(FLAG_PULL_DOWN, &desc->flags);
3850 ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
3854 /* No particular flag request, return here... */
3855 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3856 gpiod_dbg(desc, "no flags found for %s\n", con_id);
3861 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3862 ret = gpiod_direction_output(desc,
3863 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3865 ret = gpiod_direction_input(desc);
3871 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3872 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3873 * @con_id: function within the GPIO consumer
3874 * @idx: index of the GPIO to obtain in the consumer
3875 * @flags: optional GPIO initialization flags
3877 * This variant of gpiod_get() allows to access GPIOs other than the first
3878 * defined one for functions that define several GPIOs.
3880 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3881 * requested function and/or index, or another IS_ERR() code if an error
3882 * occurred while trying to acquire the GPIO.
3884 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3887 enum gpiod_flags flags)
3889 unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
3890 struct gpio_desc *desc = NULL;
3892 /* Maybe we have a device name, maybe not */
3893 const char *devname = dev ? dev_name(dev) : "?";
3894 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
3896 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3898 /* Using device tree? */
3899 if (is_of_node(fwnode)) {
3900 dev_dbg(dev, "using device tree for GPIO lookup\n");
3901 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3902 } else if (is_acpi_node(fwnode)) {
3903 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3904 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
3908 * Either we are not using DT or ACPI, or their lookup did not return
3909 * a result. In that case, use platform lookup as a fallback.
3911 if (!desc || gpiod_not_found(desc)) {
3912 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3913 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3917 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
3922 * If a connection label was passed use that, else attempt to use
3923 * the device name as label
3925 ret = gpiod_request(desc, con_id ? con_id : devname);
3927 if (ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
3929 * This happens when there are several consumers for
3930 * the same GPIO line: we just return here without
3931 * further initialization. It is a bit if a hack.
3932 * This is necessary to support fixed regulators.
3934 * FIXME: Make this more sane and safe.
3936 dev_info(dev, "nonexclusive access to GPIO for %s\n",
3937 con_id ? con_id : devname);
3940 return ERR_PTR(ret);
3944 ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3946 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3948 return ERR_PTR(ret);
3951 blocking_notifier_call_chain(&desc->gdev->notifier,
3952 GPIOLINE_CHANGED_REQUESTED, desc);
3956 EXPORT_SYMBOL_GPL(gpiod_get_index);
3959 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3960 * @fwnode: handle of the firmware node
3961 * @propname: name of the firmware property representing the GPIO
3962 * @index: index of the GPIO to obtain for the consumer
3963 * @dflags: GPIO initialization flags
3964 * @label: label to attach to the requested GPIO
3966 * This function can be used for drivers that get their configuration
3967 * from opaque firmware.
3969 * The function properly finds the corresponding GPIO using whatever is the
3970 * underlying firmware interface and then makes sure that the GPIO
3971 * descriptor is requested before it is returned to the caller.
3974 * On successful request the GPIO pin is configured in accordance with
3977 * In case of error an ERR_PTR() is returned.
3979 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
3980 const char *propname, int index,
3981 enum gpiod_flags dflags,
3984 unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
3985 struct gpio_desc *desc = ERR_PTR(-ENODEV);
3988 if (is_of_node(fwnode)) {
3989 desc = gpiod_get_from_of_node(to_of_node(fwnode),
3994 } else if (is_acpi_node(fwnode)) {
3995 struct acpi_gpio_info info;
3997 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4001 acpi_gpio_update_gpiod_flags(&dflags, &info);
4002 acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
4004 return ERR_PTR(-EINVAL);
4006 /* Currently only ACPI takes this path */
4007 ret = gpiod_request(desc, label);
4009 return ERR_PTR(ret);
4011 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4014 return ERR_PTR(ret);
4017 blocking_notifier_call_chain(&desc->gdev->notifier,
4018 GPIOLINE_CHANGED_REQUESTED, desc);
4022 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4025 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4027 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4028 * @con_id: function within the GPIO consumer
4029 * @index: index of the GPIO to obtain in the consumer
4030 * @flags: optional GPIO initialization flags
4032 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4033 * specified index was assigned to the requested function it will return NULL.
4034 * This is convenient for drivers that need to handle optional GPIOs.
4036 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4039 enum gpiod_flags flags)
4041 struct gpio_desc *desc;
4043 desc = gpiod_get_index(dev, con_id, index, flags);
4044 if (gpiod_not_found(desc))
4049 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4052 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4053 * @desc: gpio whose value will be assigned
4054 * @name: gpio line name
4055 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4056 * of_find_gpio() or of_get_gpio_hog()
4057 * @dflags: gpiod_flags - optional GPIO initialization flags
4059 int gpiod_hog(struct gpio_desc *desc, const char *name,
4060 unsigned long lflags, enum gpiod_flags dflags)
4062 struct gpio_chip *gc;
4063 struct gpio_desc *local_desc;
4067 gc = gpiod_to_chip(desc);
4068 hwnum = gpio_chip_hwgpio(desc);
4070 local_desc = gpiochip_request_own_desc(gc, hwnum, name,
4072 if (IS_ERR(local_desc)) {
4073 ret = PTR_ERR(local_desc);
4074 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4075 name, gc->label, hwnum, ret);
4079 /* Mark GPIO as hogged so it can be identified and removed later */
4080 set_bit(FLAG_IS_HOGGED, &desc->flags);
4082 gpiod_info(desc, "hogged as %s%s\n",
4083 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4084 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
4085 (dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : "");
4091 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4092 * @gc: gpio chip to act on
4094 static void gpiochip_free_hogs(struct gpio_chip *gc)
4098 for (id = 0; id < gc->ngpio; id++) {
4099 if (test_bit(FLAG_IS_HOGGED, &gc->gpiodev->descs[id].flags))
4100 gpiochip_free_own_desc(&gc->gpiodev->descs[id]);
4105 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4106 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4107 * @con_id: function within the GPIO consumer
4108 * @flags: optional GPIO initialization flags
4110 * This function acquires all the GPIOs defined under a given function.
4112 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4113 * no GPIO has been assigned to the requested function, or another IS_ERR()
4114 * code if an error occurred while trying to acquire the GPIOs.
4116 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4118 enum gpiod_flags flags)
4120 struct gpio_desc *desc;
4121 struct gpio_descs *descs;
4122 struct gpio_array *array_info = NULL;
4123 struct gpio_chip *gc;
4124 int count, bitmap_size;
4126 count = gpiod_count(dev, con_id);
4128 return ERR_PTR(count);
4130 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4132 return ERR_PTR(-ENOMEM);
4134 for (descs->ndescs = 0; descs->ndescs < count; ) {
4135 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4137 gpiod_put_array(descs);
4138 return ERR_CAST(desc);
4141 descs->desc[descs->ndescs] = desc;
4143 gc = gpiod_to_chip(desc);
4145 * If pin hardware number of array member 0 is also 0, select
4146 * its chip as a candidate for fast bitmap processing path.
4148 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4149 struct gpio_descs *array;
4151 bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?
4154 array = kzalloc(struct_size(descs, desc, count) +
4155 struct_size(array_info, invert_mask,
4156 3 * bitmap_size), GFP_KERNEL);
4158 gpiod_put_array(descs);
4159 return ERR_PTR(-ENOMEM);
4162 memcpy(array, descs,
4163 struct_size(descs, desc, descs->ndescs + 1));
4167 array_info = (void *)(descs->desc + count);
4168 array_info->get_mask = array_info->invert_mask +
4170 array_info->set_mask = array_info->get_mask +
4173 array_info->desc = descs->desc;
4174 array_info->size = count;
4175 array_info->chip = gc;
4176 bitmap_set(array_info->get_mask, descs->ndescs,
4177 count - descs->ndescs);
4178 bitmap_set(array_info->set_mask, descs->ndescs,
4179 count - descs->ndescs);
4180 descs->info = array_info;
4182 /* Unmark array members which don't belong to the 'fast' chip */
4183 if (array_info && array_info->chip != gc) {
4184 __clear_bit(descs->ndescs, array_info->get_mask);
4185 __clear_bit(descs->ndescs, array_info->set_mask);
4188 * Detect array members which belong to the 'fast' chip
4189 * but their pins are not in hardware order.
4191 else if (array_info &&
4192 gpio_chip_hwgpio(desc) != descs->ndescs) {
4194 * Don't use fast path if all array members processed so
4195 * far belong to the same chip as this one but its pin
4196 * hardware number is different from its array index.
4198 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4201 __clear_bit(descs->ndescs,
4202 array_info->get_mask);
4203 __clear_bit(descs->ndescs,
4204 array_info->set_mask);
4206 } else if (array_info) {
4207 /* Exclude open drain or open source from fast output */
4208 if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||
4209 gpiochip_line_is_open_source(gc, descs->ndescs))
4210 __clear_bit(descs->ndescs,
4211 array_info->set_mask);
4212 /* Identify 'fast' pins which require invertion */
4213 if (gpiod_is_active_low(desc))
4214 __set_bit(descs->ndescs,
4215 array_info->invert_mask);
4222 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4223 array_info->chip->label, array_info->size,
4224 *array_info->get_mask, *array_info->set_mask,
4225 *array_info->invert_mask);
4228 EXPORT_SYMBOL_GPL(gpiod_get_array);
4231 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4233 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4234 * @con_id: function within the GPIO consumer
4235 * @flags: optional GPIO initialization flags
4237 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4238 * assigned to the requested function it will return NULL.
4240 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4242 enum gpiod_flags flags)
4244 struct gpio_descs *descs;
4246 descs = gpiod_get_array(dev, con_id, flags);
4247 if (gpiod_not_found(descs))
4252 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4255 * gpiod_put - dispose of a GPIO descriptor
4256 * @desc: GPIO descriptor to dispose of
4258 * No descriptor can be used after gpiod_put() has been called on it.
4260 void gpiod_put(struct gpio_desc *desc)
4265 EXPORT_SYMBOL_GPL(gpiod_put);
4268 * gpiod_put_array - dispose of multiple GPIO descriptors
4269 * @descs: struct gpio_descs containing an array of descriptors
4271 void gpiod_put_array(struct gpio_descs *descs)
4275 for (i = 0; i < descs->ndescs; i++)
4276 gpiod_put(descs->desc[i]);
4280 EXPORT_SYMBOL_GPL(gpiod_put_array);
4283 static int gpio_bus_match(struct device *dev, struct device_driver *drv)
4285 struct fwnode_handle *fwnode = dev_fwnode(dev);
4288 * Only match if the fwnode doesn't already have a proper struct device
4291 if (fwnode && fwnode->dev != dev)
4296 static int gpio_stub_drv_probe(struct device *dev)
4299 * The DT node of some GPIO chips have a "compatible" property, but
4300 * never have a struct device added and probed by a driver to register
4301 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
4302 * the consumers of the GPIO chip to get probe deferred forever because
4303 * they will be waiting for a device associated with the GPIO chip
4304 * firmware node to get added and bound to a driver.
4306 * To allow these consumers to probe, we associate the struct
4307 * gpio_device of the GPIO chip with the firmware node and then simply
4308 * bind it to this stub driver.
4313 static struct device_driver gpio_stub_drv = {
4314 .name = "gpio_stub_drv",
4315 .bus = &gpio_bus_type,
4316 .probe = gpio_stub_drv_probe,
4319 static int __init gpiolib_dev_init(void)
4323 /* Register GPIO sysfs bus */
4324 ret = bus_register(&gpio_bus_type);
4326 pr_err("gpiolib: could not register GPIO bus type\n");
4330 ret = driver_register(&gpio_stub_drv);
4332 pr_err("gpiolib: could not register GPIO stub driver\n");
4333 bus_unregister(&gpio_bus_type);
4337 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
4339 pr_err("gpiolib: failed to allocate char dev region\n");
4340 driver_unregister(&gpio_stub_drv);
4341 bus_unregister(&gpio_bus_type);
4345 gpiolib_initialized = true;
4346 gpiochip_setup_devs();
4348 #if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
4349 WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
4350 #endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
4354 core_initcall(gpiolib_dev_init);
4356 #ifdef CONFIG_DEBUG_FS
4358 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4361 struct gpio_chip *gc = gdev->chip;
4362 unsigned gpio = gdev->base;
4363 struct gpio_desc *gdesc = &gdev->descs[0];
4368 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4369 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4371 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4377 gpiod_get_direction(gdesc);
4378 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4379 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4380 active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
4381 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
4382 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4383 is_out ? "out" : "in ",
4384 gc->get ? (gc->get(gc, i) ? "hi" : "lo") : "? ",
4385 is_irq ? "IRQ " : "",
4386 active_low ? "ACTIVE LOW" : "");
4387 seq_printf(s, "\n");
4391 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4393 unsigned long flags;
4394 struct gpio_device *gdev = NULL;
4395 loff_t index = *pos;
4399 spin_lock_irqsave(&gpio_lock, flags);
4400 list_for_each_entry(gdev, &gpio_devices, list)
4402 spin_unlock_irqrestore(&gpio_lock, flags);
4405 spin_unlock_irqrestore(&gpio_lock, flags);
4410 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4412 unsigned long flags;
4413 struct gpio_device *gdev = v;
4416 spin_lock_irqsave(&gpio_lock, flags);
4417 if (list_is_last(&gdev->list, &gpio_devices))
4420 ret = list_entry(gdev->list.next, struct gpio_device, list);
4421 spin_unlock_irqrestore(&gpio_lock, flags);
4429 static void gpiolib_seq_stop(struct seq_file *s, void *v)
4433 static int gpiolib_seq_show(struct seq_file *s, void *v)
4435 struct gpio_device *gdev = v;
4436 struct gpio_chip *gc = gdev->chip;
4437 struct device *parent;
4440 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4441 dev_name(&gdev->dev));
4445 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4446 dev_name(&gdev->dev),
4447 gdev->base, gdev->base + gdev->ngpio - 1);
4448 parent = gc->parent;
4450 seq_printf(s, ", parent: %s/%s",
4451 parent->bus ? parent->bus->name : "no-bus",
4454 seq_printf(s, ", %s", gc->label);
4456 seq_printf(s, ", can sleep");
4457 seq_printf(s, ":\n");
4460 gc->dbg_show(s, gc);
4462 gpiolib_dbg_show(s, gdev);
4467 static const struct seq_operations gpiolib_sops = {
4468 .start = gpiolib_seq_start,
4469 .next = gpiolib_seq_next,
4470 .stop = gpiolib_seq_stop,
4471 .show = gpiolib_seq_show,
4473 DEFINE_SEQ_ATTRIBUTE(gpiolib);
4475 static int __init gpiolib_debugfs_init(void)
4477 /* /sys/kernel/debug/gpio */
4478 debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);
4481 subsys_initcall(gpiolib_debugfs_init);
4483 #endif /* DEBUG_FS */