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_first_entry(&gpio_devices, 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_last_entry(&gpio_devices, 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++) {
427 * Allow overriding "fixed" names provided by the GPIO
428 * provider. The "fixed" names are more often than not
429 * generic and less informative than the names given in
432 if (names[chip->offset + i] && names[chip->offset + i][0])
433 gdev->descs[i].name = names[chip->offset + i];
441 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)
445 p = bitmap_alloc(gc->ngpio, GFP_KERNEL);
449 /* Assume by default all GPIOs are valid */
450 bitmap_fill(p, gc->ngpio);
455 static int gpiochip_alloc_valid_mask(struct gpio_chip *gc)
457 if (!(of_gpio_need_valid_mask(gc) || gc->init_valid_mask))
460 gc->valid_mask = gpiochip_allocate_mask(gc);
467 static int gpiochip_init_valid_mask(struct gpio_chip *gc)
469 if (gc->init_valid_mask)
470 return gc->init_valid_mask(gc,
477 static void gpiochip_free_valid_mask(struct gpio_chip *gc)
479 bitmap_free(gc->valid_mask);
480 gc->valid_mask = NULL;
483 static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
485 if (gc->add_pin_ranges)
486 return gc->add_pin_ranges(gc);
491 bool gpiochip_line_is_valid(const struct gpio_chip *gc,
494 /* No mask means all valid */
495 if (likely(!gc->valid_mask))
497 return test_bit(offset, gc->valid_mask);
499 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
501 static void gpiodevice_release(struct device *dev)
503 struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
506 spin_lock_irqsave(&gpio_lock, flags);
507 list_del(&gdev->list);
508 spin_unlock_irqrestore(&gpio_lock, flags);
510 ida_free(&gpio_ida, gdev->id);
511 kfree_const(gdev->label);
516 #ifdef CONFIG_GPIO_CDEV
517 #define gcdev_register(gdev, devt) gpiolib_cdev_register((gdev), (devt))
518 #define gcdev_unregister(gdev) gpiolib_cdev_unregister((gdev))
521 * gpiolib_cdev_register() indirectly calls device_add(), which is still
522 * required even when cdev is not selected.
524 #define gcdev_register(gdev, devt) device_add(&(gdev)->dev)
525 #define gcdev_unregister(gdev) device_del(&(gdev)->dev)
528 static int gpiochip_setup_dev(struct gpio_device *gdev)
532 ret = gcdev_register(gdev, gpio_devt);
536 ret = gpiochip_sysfs_register(gdev);
538 goto err_remove_device;
540 /* From this point, the .release() function cleans up gpio_device */
541 gdev->dev.release = gpiodevice_release;
542 dev_dbg(&gdev->dev, "registered GPIOs %d to %d on %s\n", gdev->base,
543 gdev->base + gdev->ngpio - 1, gdev->chip->label ? : "generic");
548 gcdev_unregister(gdev);
552 static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
554 struct gpio_desc *desc;
557 desc = gpiochip_get_desc(gc, hog->chip_hwnum);
559 chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,
564 if (test_bit(FLAG_IS_HOGGED, &desc->flags))
567 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
569 gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",
570 __func__, gc->label, hog->chip_hwnum, rv);
573 static void machine_gpiochip_add(struct gpio_chip *gc)
575 struct gpiod_hog *hog;
577 mutex_lock(&gpio_machine_hogs_mutex);
579 list_for_each_entry(hog, &gpio_machine_hogs, list) {
580 if (!strcmp(gc->label, hog->chip_label))
581 gpiochip_machine_hog(gc, hog);
584 mutex_unlock(&gpio_machine_hogs_mutex);
587 static void gpiochip_setup_devs(void)
589 struct gpio_device *gdev;
592 list_for_each_entry(gdev, &gpio_devices, list) {
593 ret = gpiochip_setup_dev(gdev);
596 "Failed to initialize gpio device (%d)\n", ret);
600 int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
601 struct lock_class_key *lock_key,
602 struct lock_class_key *request_key)
604 struct fwnode_handle *fwnode = NULL;
605 struct gpio_device *gdev;
615 fwnode = dev_fwnode(gc->parent);
618 * First: allocate and populate the internal stat container, and
619 * set up the struct device.
621 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
624 gdev->dev.bus = &gpio_bus_type;
625 gdev->dev.parent = gc->parent;
629 of_gpio_dev_init(gc, gdev);
630 acpi_gpio_dev_init(gc, gdev);
633 * Assign fwnode depending on the result of the previous calls,
634 * if none of them succeed, assign it to the parent's one.
636 gdev->dev.fwnode = dev_fwnode(&gdev->dev) ?: fwnode;
638 gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
644 ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
648 device_initialize(&gdev->dev);
649 if (gc->parent && gc->parent->driver)
650 gdev->owner = gc->parent->driver->owner;
652 /* TODO: remove chip->owner */
653 gdev->owner = gc->owner;
655 gdev->owner = THIS_MODULE;
657 gdev->descs = kcalloc(gc->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
660 goto err_free_dev_name;
664 * Try the device properties if the driver didn't supply the number
667 if (gc->ngpio == 0) {
668 ret = device_property_read_u32(&gdev->dev, "ngpios", &ngpios);
671 * -ENODATA means that there is no property found and
672 * we want to issue the error message to the user.
673 * Besides that, we want to return different error code
674 * to state that supplied value is not valid.
683 if (gc->ngpio == 0) {
684 chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
689 if (gc->ngpio > FASTPATH_NGPIO)
690 chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n",
691 gc->ngpio, FASTPATH_NGPIO);
693 gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
699 gdev->ngpio = gc->ngpio;
702 spin_lock_irqsave(&gpio_lock, flags);
705 * TODO: this allocates a Linux GPIO number base in the global
706 * GPIO numberspace for this chip. In the long run we want to
707 * get *rid* of this numberspace and use only descriptors, but
708 * it may be a pipe dream. It will not happen before we get rid
709 * of the sysfs interface anyways.
712 base = gpiochip_find_base(gc->ngpio);
715 spin_unlock_irqrestore(&gpio_lock, flags);
719 * TODO: it should not be necessary to reflect the assigned
720 * base outside of the GPIO subsystem. Go over drivers and
721 * see if anyone makes use of this, else drop this and assign
728 ret = gpiodev_add_to_list(gdev);
730 spin_unlock_irqrestore(&gpio_lock, flags);
734 for (i = 0; i < gc->ngpio; i++)
735 gdev->descs[i].gdev = gdev;
737 spin_unlock_irqrestore(&gpio_lock, flags);
739 BLOCKING_INIT_NOTIFIER_HEAD(&gdev->notifier);
741 #ifdef CONFIG_PINCTRL
742 INIT_LIST_HEAD(&gdev->pin_ranges);
746 ret = gpiochip_set_desc_names(gc);
748 goto err_remove_from_list;
750 ret = devprop_gpiochip_set_names(gc);
752 goto err_remove_from_list;
754 ret = gpiochip_alloc_valid_mask(gc);
756 goto err_remove_from_list;
758 ret = of_gpiochip_add(gc);
760 goto err_free_gpiochip_mask;
762 ret = gpiochip_init_valid_mask(gc);
764 goto err_remove_of_chip;
766 for (i = 0; i < gc->ngpio; i++) {
767 struct gpio_desc *desc = &gdev->descs[i];
769 if (gc->get_direction && gpiochip_line_is_valid(gc, i)) {
770 assign_bit(FLAG_IS_OUT,
771 &desc->flags, !gc->get_direction(gc, i));
773 assign_bit(FLAG_IS_OUT,
774 &desc->flags, !gc->direction_input);
778 ret = gpiochip_add_pin_ranges(gc);
780 goto err_remove_of_chip;
782 acpi_gpiochip_add(gc);
784 machine_gpiochip_add(gc);
786 ret = gpiochip_irqchip_init_valid_mask(gc);
788 goto err_remove_acpi_chip;
790 ret = gpiochip_irqchip_init_hw(gc);
792 goto err_remove_acpi_chip;
794 ret = gpiochip_add_irqchip(gc, lock_key, request_key);
796 goto err_remove_irqchip_mask;
799 * By first adding the chardev, and then adding the device,
800 * we get a device node entry in sysfs under
801 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
802 * coldplug of device nodes and other udev business.
803 * We can do this only if gpiolib has been initialized.
804 * Otherwise, defer until later.
806 if (gpiolib_initialized) {
807 ret = gpiochip_setup_dev(gdev);
809 goto err_remove_irqchip;
814 gpiochip_irqchip_remove(gc);
815 err_remove_irqchip_mask:
816 gpiochip_irqchip_free_valid_mask(gc);
817 err_remove_acpi_chip:
818 acpi_gpiochip_remove(gc);
820 gpiochip_free_hogs(gc);
821 of_gpiochip_remove(gc);
822 err_free_gpiochip_mask:
823 gpiochip_remove_pin_ranges(gc);
824 gpiochip_free_valid_mask(gc);
825 err_remove_from_list:
826 spin_lock_irqsave(&gpio_lock, flags);
827 list_del(&gdev->list);
828 spin_unlock_irqrestore(&gpio_lock, flags);
830 kfree_const(gdev->label);
834 kfree(dev_name(&gdev->dev));
836 ida_free(&gpio_ida, gdev->id);
838 /* failures here can mean systems won't boot... */
839 if (ret != -EPROBE_DEFER) {
840 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
841 gdev->base, gdev->base + gdev->ngpio - 1,
842 gc->label ? : "generic", ret);
847 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
850 * gpiochip_get_data() - get per-subdriver data for the chip
854 * The per-subdriver data for the chip.
856 void *gpiochip_get_data(struct gpio_chip *gc)
858 return gc->gpiodev->data;
860 EXPORT_SYMBOL_GPL(gpiochip_get_data);
863 * gpiochip_remove() - unregister a gpio_chip
864 * @gc: the chip to unregister
866 * A gpio_chip with any GPIOs still requested may not be removed.
868 void gpiochip_remove(struct gpio_chip *gc)
870 struct gpio_device *gdev = gc->gpiodev;
874 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
875 gpiochip_sysfs_unregister(gdev);
876 gpiochip_free_hogs(gc);
877 /* Numb the device, cancelling all outstanding operations */
879 gpiochip_irqchip_remove(gc);
880 acpi_gpiochip_remove(gc);
881 of_gpiochip_remove(gc);
882 gpiochip_remove_pin_ranges(gc);
883 gpiochip_free_valid_mask(gc);
885 * We accept no more calls into the driver from this point, so
886 * NULL the driver data pointer
890 spin_lock_irqsave(&gpio_lock, flags);
891 for (i = 0; i < gdev->ngpio; i++) {
892 if (gpiochip_is_requested(gc, i))
895 spin_unlock_irqrestore(&gpio_lock, flags);
897 if (i != gdev->ngpio)
899 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
902 * The gpiochip side puts its use of the device to rest here:
903 * if there are no userspace clients, the chardev and device will
904 * be removed, else it will be dangling until the last user is
907 gcdev_unregister(gdev);
908 put_device(&gdev->dev);
910 EXPORT_SYMBOL_GPL(gpiochip_remove);
913 * gpiochip_find() - iterator for locating a specific gpio_chip
914 * @data: data to pass to match function
915 * @match: Callback function to check gpio_chip
917 * Similar to bus_find_device. It returns a reference to a gpio_chip as
918 * determined by a user supplied @match callback. The callback should return
919 * 0 if the device doesn't match and non-zero if it does. If the callback is
920 * non-zero, this function will return to the caller and not iterate over any
923 struct gpio_chip *gpiochip_find(void *data,
924 int (*match)(struct gpio_chip *gc,
927 struct gpio_device *gdev;
928 struct gpio_chip *gc = NULL;
931 spin_lock_irqsave(&gpio_lock, flags);
932 list_for_each_entry(gdev, &gpio_devices, list)
933 if (gdev->chip && match(gdev->chip, data)) {
938 spin_unlock_irqrestore(&gpio_lock, flags);
942 EXPORT_SYMBOL_GPL(gpiochip_find);
944 static int gpiochip_match_name(struct gpio_chip *gc, void *data)
946 const char *name = data;
948 return !strcmp(gc->label, name);
951 static struct gpio_chip *find_chip_by_name(const char *name)
953 return gpiochip_find((void *)name, gpiochip_match_name);
956 #ifdef CONFIG_GPIOLIB_IRQCHIP
959 * The following is irqchip helper code for gpiochips.
962 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
964 struct gpio_irq_chip *girq = &gc->irq;
969 return girq->init_hw(gc);
972 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
974 struct gpio_irq_chip *girq = &gc->irq;
976 if (!girq->init_valid_mask)
979 girq->valid_mask = gpiochip_allocate_mask(gc);
980 if (!girq->valid_mask)
983 girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
988 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
990 bitmap_free(gc->irq.valid_mask);
991 gc->irq.valid_mask = NULL;
994 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
997 if (!gpiochip_line_is_valid(gc, offset))
999 /* No mask means all valid */
1000 if (likely(!gc->irq.valid_mask))
1002 return test_bit(offset, gc->irq.valid_mask);
1004 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1006 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1009 * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
1011 * @gc: the gpiochip to set the irqchip hierarchical handler to
1012 * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
1013 * will then percolate up to the parent
1015 static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
1016 struct irq_chip *irqchip)
1018 /* DT will deal with mapping each IRQ as we go along */
1019 if (is_of_node(gc->irq.fwnode))
1023 * This is for legacy and boardfile "irqchip" fwnodes: allocate
1024 * irqs upfront instead of dynamically since we don't have the
1025 * dynamic type of allocation that hardware description languages
1026 * provide. Once all GPIO drivers using board files are gone from
1027 * the kernel we can delete this code, but for a transitional period
1028 * it is necessary to keep this around.
1030 if (is_fwnode_irqchip(gc->irq.fwnode)) {
1034 for (i = 0; i < gc->ngpio; i++) {
1035 struct irq_fwspec fwspec;
1036 unsigned int parent_hwirq;
1037 unsigned int parent_type;
1038 struct gpio_irq_chip *girq = &gc->irq;
1041 * We call the child to parent translation function
1042 * only to check if the child IRQ is valid or not.
1043 * Just pick the rising edge type here as that is what
1044 * we likely need to support.
1046 ret = girq->child_to_parent_hwirq(gc, i,
1047 IRQ_TYPE_EDGE_RISING,
1051 chip_err(gc, "skip set-up on hwirq %d\n",
1056 fwspec.fwnode = gc->irq.fwnode;
1057 /* This is the hwirq for the GPIO line side of things */
1058 fwspec.param[0] = girq->child_offset_to_irq(gc, i);
1059 /* Just pick something */
1060 fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
1061 fwspec.param_count = 2;
1062 ret = __irq_domain_alloc_irqs(gc->irq.domain,
1063 /* just pick something */
1072 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
1079 chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
1084 static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
1085 struct irq_fwspec *fwspec,
1086 unsigned long *hwirq,
1089 /* We support standard DT translation */
1090 if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
1091 return irq_domain_translate_twocell(d, fwspec, hwirq, type);
1094 /* This is for board files and others not using DT */
1095 if (is_fwnode_irqchip(fwspec->fwnode)) {
1098 ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
1101 WARN_ON(*type == IRQ_TYPE_NONE);
1107 static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
1109 unsigned int nr_irqs,
1112 struct gpio_chip *gc = d->host_data;
1113 irq_hw_number_t hwirq;
1114 unsigned int type = IRQ_TYPE_NONE;
1115 struct irq_fwspec *fwspec = data;
1117 unsigned int parent_hwirq;
1118 unsigned int parent_type;
1119 struct gpio_irq_chip *girq = &gc->irq;
1123 * The nr_irqs parameter is always one except for PCI multi-MSI
1124 * so this should not happen.
1126 WARN_ON(nr_irqs != 1);
1128 ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
1132 chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
1134 ret = girq->child_to_parent_hwirq(gc, hwirq, type,
1135 &parent_hwirq, &parent_type);
1137 chip_err(gc, "can't look up hwirq %lu\n", hwirq);
1140 chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
1143 * We set handle_bad_irq because the .set_type() should
1144 * always be invoked and set the right type of handler.
1146 irq_domain_set_info(d,
1155 /* This parent only handles asserted level IRQs */
1156 parent_arg = girq->populate_parent_alloc_arg(gc, parent_hwirq, parent_type);
1160 chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
1162 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1163 ret = irq_domain_alloc_irqs_parent(d, irq, 1, parent_arg);
1165 * If the parent irqdomain is msi, the interrupts have already
1166 * been allocated, so the EEXIST is good.
1168 if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
1172 "failed to allocate parent hwirq %d for hwirq %lu\n",
1173 parent_hwirq, hwirq);
1179 static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
1180 unsigned int offset)
1185 static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
1187 ops->activate = gpiochip_irq_domain_activate;
1188 ops->deactivate = gpiochip_irq_domain_deactivate;
1189 ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
1190 ops->free = irq_domain_free_irqs_common;
1193 * We only allow overriding the translate() function for
1194 * hierarchical chips, and this should only be done if the user
1195 * really need something other than 1:1 translation.
1197 if (!ops->translate)
1198 ops->translate = gpiochip_hierarchy_irq_domain_translate;
1201 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1203 if (!gc->irq.child_to_parent_hwirq ||
1205 chip_err(gc, "missing irqdomain vital data\n");
1209 if (!gc->irq.child_offset_to_irq)
1210 gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
1212 if (!gc->irq.populate_parent_alloc_arg)
1213 gc->irq.populate_parent_alloc_arg =
1214 gpiochip_populate_parent_fwspec_twocell;
1216 gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
1218 gc->irq.domain = irq_domain_create_hierarchy(
1219 gc->irq.parent_domain,
1223 &gc->irq.child_irq_domain_ops,
1226 if (!gc->irq.domain)
1229 gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
1234 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1236 return !!gc->irq.parent_domain;
1239 void *gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
1240 unsigned int parent_hwirq,
1241 unsigned int parent_type)
1243 struct irq_fwspec *fwspec;
1245 fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
1249 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1250 fwspec->param_count = 2;
1251 fwspec->param[0] = parent_hwirq;
1252 fwspec->param[1] = parent_type;
1256 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
1258 void *gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
1259 unsigned int parent_hwirq,
1260 unsigned int parent_type)
1262 struct irq_fwspec *fwspec;
1264 fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
1268 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1269 fwspec->param_count = 4;
1270 fwspec->param[0] = 0;
1271 fwspec->param[1] = parent_hwirq;
1272 fwspec->param[2] = 0;
1273 fwspec->param[3] = parent_type;
1277 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
1281 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1286 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1291 #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
1294 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1295 * @d: the irqdomain used by this irqchip
1296 * @irq: the global irq number used by this GPIO irqchip irq
1297 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1299 * This function will set up the mapping for a certain IRQ line on a
1300 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1301 * stored inside the gpiochip.
1303 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1304 irq_hw_number_t hwirq)
1306 struct gpio_chip *gc = d->host_data;
1309 if (!gpiochip_irqchip_irq_valid(gc, hwirq))
1312 irq_set_chip_data(irq, gc);
1314 * This lock class tells lockdep that GPIO irqs are in a different
1315 * category than their parents, so it won't report false recursion.
1317 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1318 irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
1319 /* Chips that use nested thread handlers have them marked */
1320 if (gc->irq.threaded)
1321 irq_set_nested_thread(irq, 1);
1322 irq_set_noprobe(irq);
1324 if (gc->irq.num_parents == 1)
1325 ret = irq_set_parent(irq, gc->irq.parents[0]);
1326 else if (gc->irq.map)
1327 ret = irq_set_parent(irq, gc->irq.map[hwirq]);
1333 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1334 * is passed as default type.
1336 if (gc->irq.default_type != IRQ_TYPE_NONE)
1337 irq_set_irq_type(irq, gc->irq.default_type);
1341 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1343 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1345 struct gpio_chip *gc = d->host_data;
1347 if (gc->irq.threaded)
1348 irq_set_nested_thread(irq, 0);
1349 irq_set_chip_and_handler(irq, NULL, NULL);
1350 irq_set_chip_data(irq, NULL);
1352 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1354 static const struct irq_domain_ops gpiochip_domain_ops = {
1355 .map = gpiochip_irq_map,
1356 .unmap = gpiochip_irq_unmap,
1357 /* Virtually all GPIO irqchips are twocell:ed */
1358 .xlate = irq_domain_xlate_twocell,
1362 * TODO: move these activate/deactivate in under the hierarchicial
1363 * irqchip implementation as static once SPMI and SSBI (all external
1364 * users) are phased over.
1367 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1368 * @domain: The IRQ domain used by this IRQ chip
1369 * @data: Outermost irq_data associated with the IRQ
1370 * @reserve: If set, only reserve an interrupt vector instead of assigning one
1372 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1373 * used as the activate function for the &struct irq_domain_ops. The host_data
1374 * for the IRQ domain must be the &struct gpio_chip.
1376 int gpiochip_irq_domain_activate(struct irq_domain *domain,
1377 struct irq_data *data, bool reserve)
1379 struct gpio_chip *gc = domain->host_data;
1381 return gpiochip_lock_as_irq(gc, data->hwirq);
1383 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
1386 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1387 * @domain: The IRQ domain used by this IRQ chip
1388 * @data: Outermost irq_data associated with the IRQ
1390 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1391 * be used as the deactivate function for the &struct irq_domain_ops. The
1392 * host_data for the IRQ domain must be the &struct gpio_chip.
1394 void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1395 struct irq_data *data)
1397 struct gpio_chip *gc = domain->host_data;
1399 return gpiochip_unlock_as_irq(gc, data->hwirq);
1401 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
1403 static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)
1405 struct irq_domain *domain = gc->irq.domain;
1407 #ifdef CONFIG_GPIOLIB_IRQCHIP
1409 * Avoid race condition with other code, which tries to lookup
1410 * an IRQ before the irqchip has been properly registered,
1411 * i.e. while gpiochip is still being brought up.
1413 if (!gc->irq.initialized)
1414 return -EPROBE_DEFER;
1417 if (!gpiochip_irqchip_irq_valid(gc, offset))
1420 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1421 if (irq_domain_is_hierarchy(domain)) {
1422 struct irq_fwspec spec;
1424 spec.fwnode = domain->fwnode;
1425 spec.param_count = 2;
1426 spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
1427 spec.param[1] = IRQ_TYPE_NONE;
1429 return irq_create_fwspec_mapping(&spec);
1433 return irq_create_mapping(domain, offset);
1436 static int gpiochip_irq_reqres(struct irq_data *d)
1438 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1440 return gpiochip_reqres_irq(gc, d->hwirq);
1443 static void gpiochip_irq_relres(struct irq_data *d)
1445 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1447 gpiochip_relres_irq(gc, d->hwirq);
1450 static void gpiochip_irq_mask(struct irq_data *d)
1452 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1454 if (gc->irq.irq_mask)
1455 gc->irq.irq_mask(d);
1456 gpiochip_disable_irq(gc, d->hwirq);
1459 static void gpiochip_irq_unmask(struct irq_data *d)
1461 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1463 gpiochip_enable_irq(gc, d->hwirq);
1464 if (gc->irq.irq_unmask)
1465 gc->irq.irq_unmask(d);
1468 static void gpiochip_irq_enable(struct irq_data *d)
1470 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1472 gpiochip_enable_irq(gc, d->hwirq);
1473 gc->irq.irq_enable(d);
1476 static void gpiochip_irq_disable(struct irq_data *d)
1478 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1480 gc->irq.irq_disable(d);
1481 gpiochip_disable_irq(gc, d->hwirq);
1484 static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
1486 struct irq_chip *irqchip = gc->irq.chip;
1488 if (!irqchip->irq_request_resources &&
1489 !irqchip->irq_release_resources) {
1490 irqchip->irq_request_resources = gpiochip_irq_reqres;
1491 irqchip->irq_release_resources = gpiochip_irq_relres;
1493 if (WARN_ON(gc->irq.irq_enable))
1495 /* Check if the irqchip already has this hook... */
1496 if (irqchip->irq_enable == gpiochip_irq_enable ||
1497 irqchip->irq_mask == gpiochip_irq_mask) {
1499 * ...and if so, give a gentle warning that this is bad
1503 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1507 if (irqchip->irq_disable) {
1508 gc->irq.irq_disable = irqchip->irq_disable;
1509 irqchip->irq_disable = gpiochip_irq_disable;
1511 gc->irq.irq_mask = irqchip->irq_mask;
1512 irqchip->irq_mask = gpiochip_irq_mask;
1515 if (irqchip->irq_enable) {
1516 gc->irq.irq_enable = irqchip->irq_enable;
1517 irqchip->irq_enable = gpiochip_irq_enable;
1519 gc->irq.irq_unmask = irqchip->irq_unmask;
1520 irqchip->irq_unmask = gpiochip_irq_unmask;
1525 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1526 * @gc: the GPIO chip to add the IRQ chip to
1527 * @lock_key: lockdep class for IRQ lock
1528 * @request_key: lockdep class for IRQ request
1530 static int gpiochip_add_irqchip(struct gpio_chip *gc,
1531 struct lock_class_key *lock_key,
1532 struct lock_class_key *request_key)
1534 struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
1535 struct irq_chip *irqchip = gc->irq.chip;
1542 if (gc->irq.parent_handler && gc->can_sleep) {
1543 chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
1547 type = gc->irq.default_type;
1550 * Specifying a default trigger is a terrible idea if DT or ACPI is
1551 * used to configure the interrupts, as you may end up with
1552 * conflicting triggers. Tell the user, and reset to NONE.
1554 if (WARN(fwnode && type != IRQ_TYPE_NONE,
1555 "%pfw: Ignoring %u default trigger\n", fwnode, type))
1556 type = IRQ_TYPE_NONE;
1559 chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__);
1561 gc->to_irq = gpiochip_to_irq;
1562 gc->irq.default_type = type;
1563 gc->irq.lock_key = lock_key;
1564 gc->irq.request_key = request_key;
1566 /* If a parent irqdomain is provided, let's build a hierarchy */
1567 if (gpiochip_hierarchy_is_hierarchical(gc)) {
1568 int ret = gpiochip_hierarchy_add_domain(gc);
1572 /* Some drivers provide custom irqdomain ops */
1573 gc->irq.domain = irq_domain_create_simple(fwnode,
1576 gc->irq.domain_ops ?: &gpiochip_domain_ops,
1578 if (!gc->irq.domain)
1582 if (gc->irq.parent_handler) {
1583 for (i = 0; i < gc->irq.num_parents; i++) {
1586 if (gc->irq.per_parent_data)
1587 data = gc->irq.parent_handler_data_array[i];
1589 data = gc->irq.parent_handler_data ?: gc;
1592 * The parent IRQ chip is already using the chip_data
1593 * for this IRQ chip, so our callbacks simply use the
1596 irq_set_chained_handler_and_data(gc->irq.parents[i],
1597 gc->irq.parent_handler,
1602 gpiochip_set_irq_hooks(gc);
1605 * Using barrier() here to prevent compiler from reordering
1606 * gc->irq.initialized before initialization of above
1607 * GPIO chip irq members.
1611 gc->irq.initialized = true;
1613 acpi_gpiochip_request_interrupts(gc);
1619 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1620 * @gc: the gpiochip to remove the irqchip from
1622 * This is called only from gpiochip_remove()
1624 static void gpiochip_irqchip_remove(struct gpio_chip *gc)
1626 struct irq_chip *irqchip = gc->irq.chip;
1627 unsigned int offset;
1629 acpi_gpiochip_free_interrupts(gc);
1631 if (irqchip && gc->irq.parent_handler) {
1632 struct gpio_irq_chip *irq = &gc->irq;
1635 for (i = 0; i < irq->num_parents; i++)
1636 irq_set_chained_handler_and_data(irq->parents[i],
1640 /* Remove all IRQ mappings and delete the domain */
1641 if (gc->irq.domain) {
1644 for (offset = 0; offset < gc->ngpio; offset++) {
1645 if (!gpiochip_irqchip_irq_valid(gc, offset))
1648 irq = irq_find_mapping(gc->irq.domain, offset);
1649 irq_dispose_mapping(irq);
1652 irq_domain_remove(gc->irq.domain);
1656 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
1657 irqchip->irq_request_resources = NULL;
1658 irqchip->irq_release_resources = NULL;
1660 if (irqchip->irq_enable == gpiochip_irq_enable) {
1661 irqchip->irq_enable = gc->irq.irq_enable;
1662 irqchip->irq_disable = gc->irq.irq_disable;
1665 gc->irq.irq_enable = NULL;
1666 gc->irq.irq_disable = NULL;
1667 gc->irq.chip = NULL;
1669 gpiochip_irqchip_free_valid_mask(gc);
1673 * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
1674 * @gc: the gpiochip to add the irqchip to
1675 * @domain: the irqdomain to add to the gpiochip
1677 * This function adds an IRQ domain to the gpiochip.
1679 int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
1680 struct irq_domain *domain)
1685 gc->to_irq = gpiochip_to_irq;
1686 gc->irq.domain = domain;
1690 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
1692 #else /* CONFIG_GPIOLIB_IRQCHIP */
1694 static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
1695 struct lock_class_key *lock_key,
1696 struct lock_class_key *request_key)
1700 static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
1702 static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1707 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1711 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
1714 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1717 * gpiochip_generic_request() - request the gpio function for a pin
1718 * @gc: the gpiochip owning the GPIO
1719 * @offset: the offset of the GPIO to request for GPIO function
1721 int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)
1723 #ifdef CONFIG_PINCTRL
1724 if (list_empty(&gc->gpiodev->pin_ranges))
1728 return pinctrl_gpio_request(gc->gpiodev->base + offset);
1730 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1733 * gpiochip_generic_free() - free the gpio function from a pin
1734 * @gc: the gpiochip to request the gpio function for
1735 * @offset: the offset of the GPIO to free from GPIO function
1737 void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset)
1739 #ifdef CONFIG_PINCTRL
1740 if (list_empty(&gc->gpiodev->pin_ranges))
1744 pinctrl_gpio_free(gc->gpiodev->base + offset);
1746 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1749 * gpiochip_generic_config() - apply configuration for a pin
1750 * @gc: the gpiochip owning the GPIO
1751 * @offset: the offset of the GPIO to apply the configuration
1752 * @config: the configuration to be applied
1754 int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
1755 unsigned long config)
1757 return pinctrl_gpio_set_config(gc->gpiodev->base + offset, config);
1759 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
1761 #ifdef CONFIG_PINCTRL
1764 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1765 * @gc: the gpiochip to add the range for
1766 * @pctldev: the pin controller to map to
1767 * @gpio_offset: the start offset in the current gpio_chip number space
1768 * @pin_group: name of the pin group inside the pin controller
1770 * Calling this function directly from a DeviceTree-supported
1771 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
1772 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
1773 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
1775 int gpiochip_add_pingroup_range(struct gpio_chip *gc,
1776 struct pinctrl_dev *pctldev,
1777 unsigned int gpio_offset, const char *pin_group)
1779 struct gpio_pin_range *pin_range;
1780 struct gpio_device *gdev = gc->gpiodev;
1783 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1785 chip_err(gc, "failed to allocate pin ranges\n");
1789 /* Use local offset as range ID */
1790 pin_range->range.id = gpio_offset;
1791 pin_range->range.gc = gc;
1792 pin_range->range.name = gc->label;
1793 pin_range->range.base = gdev->base + gpio_offset;
1794 pin_range->pctldev = pctldev;
1796 ret = pinctrl_get_group_pins(pctldev, pin_group,
1797 &pin_range->range.pins,
1798 &pin_range->range.npins);
1804 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1806 chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1807 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1808 pinctrl_dev_get_devname(pctldev), pin_group);
1810 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1814 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1817 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1818 * @gc: the gpiochip to add the range for
1819 * @pinctl_name: the dev_name() of the pin controller to map to
1820 * @gpio_offset: the start offset in the current gpio_chip number space
1821 * @pin_offset: the start offset in the pin controller number space
1822 * @npins: the number of pins from the offset of each pin space (GPIO and
1823 * pin controller) to accumulate in this range
1826 * 0 on success, or a negative error-code on failure.
1828 * Calling this function directly from a DeviceTree-supported
1829 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
1830 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
1831 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
1833 int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
1834 unsigned int gpio_offset, unsigned int pin_offset,
1837 struct gpio_pin_range *pin_range;
1838 struct gpio_device *gdev = gc->gpiodev;
1841 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1843 chip_err(gc, "failed to allocate pin ranges\n");
1847 /* Use local offset as range ID */
1848 pin_range->range.id = gpio_offset;
1849 pin_range->range.gc = gc;
1850 pin_range->range.name = gc->label;
1851 pin_range->range.base = gdev->base + gpio_offset;
1852 pin_range->range.pin_base = pin_offset;
1853 pin_range->range.npins = npins;
1854 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1856 if (IS_ERR(pin_range->pctldev)) {
1857 ret = PTR_ERR(pin_range->pctldev);
1858 chip_err(gc, "could not create pin range\n");
1862 chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1863 gpio_offset, gpio_offset + npins - 1,
1865 pin_offset, pin_offset + npins - 1);
1867 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1871 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1874 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1875 * @gc: the chip to remove all the mappings for
1877 void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
1879 struct gpio_pin_range *pin_range, *tmp;
1880 struct gpio_device *gdev = gc->gpiodev;
1882 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1883 list_del(&pin_range->node);
1884 pinctrl_remove_gpio_range(pin_range->pctldev,
1889 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1891 #endif /* CONFIG_PINCTRL */
1893 /* These "optional" allocation calls help prevent drivers from stomping
1894 * on each other, and help provide better diagnostics in debugfs.
1895 * They're called even less than the "set direction" calls.
1897 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
1899 struct gpio_chip *gc = desc->gdev->chip;
1901 unsigned long flags;
1905 label = kstrdup_const(label, GFP_KERNEL);
1910 spin_lock_irqsave(&gpio_lock, flags);
1912 /* NOTE: gpio_request() can be called in early boot,
1913 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1916 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1917 desc_set_label(desc, label ? : "?");
1920 goto out_free_unlock;
1924 /* gc->request may sleep */
1925 spin_unlock_irqrestore(&gpio_lock, flags);
1926 offset = gpio_chip_hwgpio(desc);
1927 if (gpiochip_line_is_valid(gc, offset))
1928 ret = gc->request(gc, offset);
1931 spin_lock_irqsave(&gpio_lock, flags);
1934 desc_set_label(desc, NULL);
1935 clear_bit(FLAG_REQUESTED, &desc->flags);
1936 goto out_free_unlock;
1939 if (gc->get_direction) {
1940 /* gc->get_direction may sleep */
1941 spin_unlock_irqrestore(&gpio_lock, flags);
1942 gpiod_get_direction(desc);
1943 spin_lock_irqsave(&gpio_lock, flags);
1945 spin_unlock_irqrestore(&gpio_lock, flags);
1949 spin_unlock_irqrestore(&gpio_lock, flags);
1955 * This descriptor validation needs to be inserted verbatim into each
1956 * function taking a descriptor, so we need to use a preprocessor
1957 * macro to avoid endless duplication. If the desc is NULL it is an
1958 * optional GPIO and calls should just bail out.
1960 static int validate_desc(const struct gpio_desc *desc, const char *func)
1965 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
1966 return PTR_ERR(desc);
1969 pr_warn("%s: invalid GPIO (no device)\n", func);
1972 if (!desc->gdev->chip) {
1973 dev_warn(&desc->gdev->dev,
1974 "%s: backing chip is gone\n", func);
1980 #define VALIDATE_DESC(desc) do { \
1981 int __valid = validate_desc(desc, __func__); \
1986 #define VALIDATE_DESC_VOID(desc) do { \
1987 int __valid = validate_desc(desc, __func__); \
1992 int gpiod_request(struct gpio_desc *desc, const char *label)
1994 int ret = -EPROBE_DEFER;
1995 struct gpio_device *gdev;
1997 VALIDATE_DESC(desc);
2000 if (try_module_get(gdev->owner)) {
2001 ret = gpiod_request_commit(desc, label);
2003 module_put(gdev->owner);
2005 get_device(&gdev->dev);
2009 gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
2014 static bool gpiod_free_commit(struct gpio_desc *desc)
2017 unsigned long flags;
2018 struct gpio_chip *gc;
2022 gpiod_unexport(desc);
2024 spin_lock_irqsave(&gpio_lock, flags);
2026 gc = desc->gdev->chip;
2027 if (gc && test_bit(FLAG_REQUESTED, &desc->flags)) {
2029 spin_unlock_irqrestore(&gpio_lock, flags);
2030 might_sleep_if(gc->can_sleep);
2031 gc->free(gc, gpio_chip_hwgpio(desc));
2032 spin_lock_irqsave(&gpio_lock, flags);
2034 kfree_const(desc->label);
2035 desc_set_label(desc, NULL);
2036 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2037 clear_bit(FLAG_REQUESTED, &desc->flags);
2038 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2039 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2040 clear_bit(FLAG_PULL_UP, &desc->flags);
2041 clear_bit(FLAG_PULL_DOWN, &desc->flags);
2042 clear_bit(FLAG_BIAS_DISABLE, &desc->flags);
2043 clear_bit(FLAG_EDGE_RISING, &desc->flags);
2044 clear_bit(FLAG_EDGE_FALLING, &desc->flags);
2045 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2046 #ifdef CONFIG_OF_DYNAMIC
2049 #ifdef CONFIG_GPIO_CDEV
2050 WRITE_ONCE(desc->debounce_period_us, 0);
2055 spin_unlock_irqrestore(&gpio_lock, flags);
2056 blocking_notifier_call_chain(&desc->gdev->notifier,
2057 GPIOLINE_CHANGED_RELEASED, desc);
2062 void gpiod_free(struct gpio_desc *desc)
2064 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2065 module_put(desc->gdev->owner);
2066 put_device(&desc->gdev->dev);
2068 WARN_ON(extra_checks);
2073 * gpiochip_is_requested - return string iff signal was requested
2074 * @gc: controller managing the signal
2075 * @offset: of signal within controller's 0..(ngpio - 1) range
2077 * Returns NULL if the GPIO is not currently requested, else a string.
2078 * The string returned is the label passed to gpio_request(); if none has been
2079 * passed it is a meaningless, non-NULL constant.
2081 * This function is for use by GPIO controller drivers. The label can
2082 * help with diagnostics, and knowing that the signal is used as a GPIO
2083 * can help avoid accidentally multiplexing it to another controller.
2085 const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset)
2087 struct gpio_desc *desc;
2089 desc = gpiochip_get_desc(gc, offset);
2093 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2097 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2100 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2102 * @hwnum: hardware number of the GPIO for which to request the descriptor
2103 * @label: label for the GPIO
2104 * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2105 * specify things like line inversion semantics with the machine flags
2106 * such as GPIO_OUT_LOW
2107 * @dflags: descriptor request flags for this GPIO or 0 if default, this
2108 * can be used to specify consumer semantics such as open drain
2110 * Function allows GPIO chip drivers to request and use their own GPIO
2111 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2112 * function will not increase reference count of the GPIO chip module. This
2113 * allows the GPIO chip module to be unloaded as needed (we assume that the
2114 * GPIO chip driver handles freeing the GPIOs it has requested).
2117 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2120 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
2123 enum gpio_lookup_flags lflags,
2124 enum gpiod_flags dflags)
2126 struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
2130 chip_err(gc, "failed to get GPIO descriptor\n");
2134 ret = gpiod_request_commit(desc, label);
2136 return ERR_PTR(ret);
2138 ret = gpiod_configure_flags(desc, label, lflags, dflags);
2140 chip_err(gc, "setup of own GPIO %s failed\n", label);
2141 gpiod_free_commit(desc);
2142 return ERR_PTR(ret);
2147 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2150 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2151 * @desc: GPIO descriptor to free
2153 * Function frees the given GPIO requested previously with
2154 * gpiochip_request_own_desc().
2156 void gpiochip_free_own_desc(struct gpio_desc *desc)
2159 gpiod_free_commit(desc);
2161 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2164 * Drivers MUST set GPIO direction before making get/set calls. In
2165 * some cases this is done in early boot, before IRQs are enabled.
2167 * As a rule these aren't called more than once (except for drivers
2168 * using the open-drain emulation idiom) so these are natural places
2169 * to accumulate extra debugging checks. Note that we can't (yet)
2170 * rely on gpio_request() having been called beforehand.
2173 static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset,
2174 unsigned long config)
2176 if (!gc->set_config)
2179 return gc->set_config(gc, offset, config);
2182 static int gpio_set_config_with_argument(struct gpio_desc *desc,
2183 enum pin_config_param mode,
2186 struct gpio_chip *gc = desc->gdev->chip;
2187 unsigned long config;
2189 config = pinconf_to_config_packed(mode, argument);
2190 return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
2193 static int gpio_set_config_with_argument_optional(struct gpio_desc *desc,
2194 enum pin_config_param mode,
2197 struct device *dev = &desc->gdev->dev;
2198 int gpio = gpio_chip_hwgpio(desc);
2201 ret = gpio_set_config_with_argument(desc, mode, argument);
2202 if (ret != -ENOTSUPP)
2206 case PIN_CONFIG_PERSIST_STATE:
2207 dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio);
2216 static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
2218 return gpio_set_config_with_argument(desc, mode, 0);
2221 static int gpio_set_bias(struct gpio_desc *desc)
2223 enum pin_config_param bias;
2226 if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
2227 bias = PIN_CONFIG_BIAS_DISABLE;
2228 else if (test_bit(FLAG_PULL_UP, &desc->flags))
2229 bias = PIN_CONFIG_BIAS_PULL_UP;
2230 else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
2231 bias = PIN_CONFIG_BIAS_PULL_DOWN;
2236 case PIN_CONFIG_BIAS_PULL_DOWN:
2237 case PIN_CONFIG_BIAS_PULL_UP:
2246 return gpio_set_config_with_argument_optional(desc, bias, arg);
2250 * gpio_set_debounce_timeout() - Set debounce timeout
2251 * @desc: GPIO descriptor to set the debounce timeout
2252 * @debounce: Debounce timeout in microseconds
2254 * The function calls the certain GPIO driver to set debounce timeout
2257 * Returns 0 on success, or negative error code otherwise.
2259 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
2261 return gpio_set_config_with_argument_optional(desc,
2262 PIN_CONFIG_INPUT_DEBOUNCE,
2267 * gpiod_direction_input - set the GPIO direction to input
2268 * @desc: GPIO to set to input
2270 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2271 * be called safely on it.
2273 * Return 0 in case of success, else an error code.
2275 int gpiod_direction_input(struct gpio_desc *desc)
2277 struct gpio_chip *gc;
2280 VALIDATE_DESC(desc);
2281 gc = desc->gdev->chip;
2284 * It is legal to have no .get() and .direction_input() specified if
2285 * the chip is output-only, but you can't specify .direction_input()
2286 * and not support the .get() operation, that doesn't make sense.
2288 if (!gc->get && gc->direction_input) {
2290 "%s: missing get() but have direction_input()\n",
2296 * If we have a .direction_input() callback, things are simple,
2297 * just call it. Else we are some input-only chip so try to check the
2298 * direction (if .get_direction() is supported) else we silently
2299 * assume we are in input mode after this.
2301 if (gc->direction_input) {
2302 ret = gc->direction_input(gc, gpio_chip_hwgpio(desc));
2303 } else if (gc->get_direction &&
2304 (gc->get_direction(gc, gpio_chip_hwgpio(desc)) != 1)) {
2306 "%s: missing direction_input() operation and line is output\n",
2311 clear_bit(FLAG_IS_OUT, &desc->flags);
2312 ret = gpio_set_bias(desc);
2315 trace_gpio_direction(desc_to_gpio(desc), 1, ret);
2319 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2321 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2323 struct gpio_chip *gc = desc->gdev->chip;
2328 * It's OK not to specify .direction_output() if the gpiochip is
2329 * output-only, but if there is then not even a .set() operation it
2330 * is pretty tricky to drive the output line.
2332 if (!gc->set && !gc->direction_output) {
2334 "%s: missing set() and direction_output() operations\n",
2339 if (gc->direction_output) {
2340 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2342 /* Check that we are in output mode if we can */
2343 if (gc->get_direction &&
2344 gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
2346 "%s: missing direction_output() operation\n",
2351 * If we can't actively set the direction, we are some
2352 * output-only chip, so just drive the output as desired.
2354 gc->set(gc, gpio_chip_hwgpio(desc), val);
2358 set_bit(FLAG_IS_OUT, &desc->flags);
2359 trace_gpio_value(desc_to_gpio(desc), 0, val);
2360 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2365 * gpiod_direction_output_raw - set the GPIO direction to output
2366 * @desc: GPIO to set to output
2367 * @value: initial output value of the GPIO
2369 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2370 * be called safely on it. The initial value of the output must be specified
2371 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2373 * Return 0 in case of success, else an error code.
2375 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2377 VALIDATE_DESC(desc);
2378 return gpiod_direction_output_raw_commit(desc, value);
2380 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2383 * gpiod_direction_output - set the GPIO direction to output
2384 * @desc: GPIO to set to output
2385 * @value: initial output value of the GPIO
2387 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2388 * be called safely on it. The initial value of the output must be specified
2389 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2392 * Return 0 in case of success, else an error code.
2394 int gpiod_direction_output(struct gpio_desc *desc, int value)
2398 VALIDATE_DESC(desc);
2399 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2404 /* GPIOs used for enabled IRQs shall not be set as output */
2405 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
2406 test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
2408 "%s: tried to set a GPIO tied to an IRQ as output\n",
2413 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2414 /* First see if we can enable open drain in hardware */
2415 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
2417 goto set_output_value;
2418 /* Emulate open drain by not actively driving the line high */
2420 ret = gpiod_direction_input(desc);
2421 goto set_output_flag;
2424 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2425 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
2427 goto set_output_value;
2428 /* Emulate open source by not actively driving the line low */
2430 ret = gpiod_direction_input(desc);
2431 goto set_output_flag;
2434 gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
2438 ret = gpio_set_bias(desc);
2441 return gpiod_direction_output_raw_commit(desc, value);
2445 * When emulating open-source or open-drain functionalities by not
2446 * actively driving the line (setting mode to input) we still need to
2447 * set the IS_OUT flag or otherwise we won't be able to set the line
2451 set_bit(FLAG_IS_OUT, &desc->flags);
2454 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2457 * gpiod_set_config - sets @config for a GPIO
2458 * @desc: descriptor of the GPIO for which to set the configuration
2459 * @config: Same packed config format as generic pinconf
2462 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2465 int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
2467 struct gpio_chip *gc;
2469 VALIDATE_DESC(desc);
2470 gc = desc->gdev->chip;
2472 return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
2474 EXPORT_SYMBOL_GPL(gpiod_set_config);
2477 * gpiod_set_debounce - sets @debounce time for a GPIO
2478 * @desc: descriptor of the GPIO for which to set debounce time
2479 * @debounce: debounce time in microseconds
2482 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2485 int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce)
2487 unsigned long config;
2489 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2490 return gpiod_set_config(desc, config);
2492 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2495 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2496 * @desc: descriptor of the GPIO for which to configure persistence
2497 * @transitory: True to lose state on suspend or reset, false for persistence
2500 * 0 on success, otherwise a negative error code.
2502 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2504 VALIDATE_DESC(desc);
2506 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2507 * persistence state.
2509 assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
2511 /* If the driver supports it, set the persistence state now */
2512 return gpio_set_config_with_argument_optional(desc,
2513 PIN_CONFIG_PERSIST_STATE,
2516 EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2519 * gpiod_is_active_low - test whether a GPIO is active-low or not
2520 * @desc: the gpio descriptor to test
2522 * Returns 1 if the GPIO is active-low, 0 otherwise.
2524 int gpiod_is_active_low(const struct gpio_desc *desc)
2526 VALIDATE_DESC(desc);
2527 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2529 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2532 * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
2533 * @desc: the gpio descriptor to change
2535 void gpiod_toggle_active_low(struct gpio_desc *desc)
2537 VALIDATE_DESC_VOID(desc);
2538 change_bit(FLAG_ACTIVE_LOW, &desc->flags);
2540 EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
2542 /* I/O calls are only valid after configuration completed; the relevant
2543 * "is this a valid GPIO" error checks should already have been done.
2545 * "Get" operations are often inlinable as reading a pin value register,
2546 * and masking the relevant bit in that register.
2548 * When "set" operations are inlinable, they involve writing that mask to
2549 * one register to set a low value, or a different register to set it high.
2550 * Otherwise locking is needed, so there may be little value to inlining.
2552 *------------------------------------------------------------------------
2554 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2555 * have requested the GPIO. That can include implicit requesting by
2556 * a direction setting call. Marking a gpio as requested locks its chip
2557 * in memory, guaranteeing that these table lookups need no more locking
2558 * and that gpiochip_remove() will fail.
2560 * REVISIT when debugging, consider adding some instrumentation to ensure
2561 * that the GPIO was actually requested.
2564 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2566 struct gpio_chip *gc;
2570 gc = desc->gdev->chip;
2571 offset = gpio_chip_hwgpio(desc);
2572 value = gc->get ? gc->get(gc, offset) : -EIO;
2573 value = value < 0 ? value : !!value;
2574 trace_gpio_value(desc_to_gpio(desc), 1, value);
2578 static int gpio_chip_get_multiple(struct gpio_chip *gc,
2579 unsigned long *mask, unsigned long *bits)
2581 if (gc->get_multiple) {
2582 return gc->get_multiple(gc, mask, bits);
2583 } else if (gc->get) {
2586 for_each_set_bit(i, mask, gc->ngpio) {
2587 value = gc->get(gc, i);
2590 __assign_bit(i, bits, value);
2597 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2598 unsigned int array_size,
2599 struct gpio_desc **desc_array,
2600 struct gpio_array *array_info,
2601 unsigned long *value_bitmap)
2606 * Validate array_info against desc_array and its size.
2607 * It should immediately follow desc_array if both
2608 * have been obtained from the same gpiod_get_array() call.
2610 if (array_info && array_info->desc == desc_array &&
2611 array_size <= array_info->size &&
2612 (void *)array_info == desc_array + array_info->size) {
2614 WARN_ON(array_info->chip->can_sleep);
2616 ret = gpio_chip_get_multiple(array_info->chip,
2617 array_info->get_mask,
2622 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2623 bitmap_xor(value_bitmap, value_bitmap,
2624 array_info->invert_mask, array_size);
2626 i = find_first_zero_bit(array_info->get_mask, array_size);
2627 if (i == array_size)
2633 while (i < array_size) {
2634 struct gpio_chip *gc = desc_array[i]->gdev->chip;
2635 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
2636 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
2637 unsigned long *mask, *bits;
2640 if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
2641 mask = fastpath_mask;
2642 bits = fastpath_bits;
2644 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
2646 mask = bitmap_alloc(gc->ngpio, flags);
2650 bits = bitmap_alloc(gc->ngpio, flags);
2657 bitmap_zero(mask, gc->ngpio);
2660 WARN_ON(gc->can_sleep);
2662 /* collect all inputs belonging to the same chip */
2665 const struct gpio_desc *desc = desc_array[i];
2666 int hwgpio = gpio_chip_hwgpio(desc);
2668 __set_bit(hwgpio, mask);
2672 i = find_next_zero_bit(array_info->get_mask,
2674 } while ((i < array_size) &&
2675 (desc_array[i]->gdev->chip == gc));
2677 ret = gpio_chip_get_multiple(gc, mask, bits);
2679 if (mask != fastpath_mask)
2681 if (bits != fastpath_bits)
2686 for (j = first; j < i; ) {
2687 const struct gpio_desc *desc = desc_array[j];
2688 int hwgpio = gpio_chip_hwgpio(desc);
2689 int value = test_bit(hwgpio, bits);
2691 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2693 __assign_bit(j, value_bitmap, value);
2694 trace_gpio_value(desc_to_gpio(desc), 1, value);
2698 j = find_next_zero_bit(array_info->get_mask, i,
2702 if (mask != fastpath_mask)
2704 if (bits != fastpath_bits)
2711 * gpiod_get_raw_value() - return a gpio's raw value
2712 * @desc: gpio whose value will be returned
2714 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2715 * its ACTIVE_LOW status, or negative errno on failure.
2717 * This function can be called from contexts where we cannot sleep, and will
2718 * complain if the GPIO chip functions potentially sleep.
2720 int gpiod_get_raw_value(const struct gpio_desc *desc)
2722 VALIDATE_DESC(desc);
2723 /* Should be using gpiod_get_raw_value_cansleep() */
2724 WARN_ON(desc->gdev->chip->can_sleep);
2725 return gpiod_get_raw_value_commit(desc);
2727 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2730 * gpiod_get_value() - return a gpio's value
2731 * @desc: gpio whose value will be returned
2733 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2734 * account, or negative errno on failure.
2736 * This function can be called from contexts where we cannot sleep, and will
2737 * complain if the GPIO chip functions potentially sleep.
2739 int gpiod_get_value(const struct gpio_desc *desc)
2743 VALIDATE_DESC(desc);
2744 /* Should be using gpiod_get_value_cansleep() */
2745 WARN_ON(desc->gdev->chip->can_sleep);
2747 value = gpiod_get_raw_value_commit(desc);
2751 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2756 EXPORT_SYMBOL_GPL(gpiod_get_value);
2759 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
2760 * @array_size: number of elements in the descriptor array / value bitmap
2761 * @desc_array: array of GPIO descriptors whose values will be read
2762 * @array_info: information on applicability of fast bitmap processing path
2763 * @value_bitmap: bitmap to store the read values
2765 * Read the raw values of the GPIOs, i.e. the values of the physical lines
2766 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
2767 * else an error code.
2769 * This function can be called from contexts where we cannot sleep,
2770 * and it will complain if the GPIO chip functions potentially sleep.
2772 int gpiod_get_raw_array_value(unsigned int array_size,
2773 struct gpio_desc **desc_array,
2774 struct gpio_array *array_info,
2775 unsigned long *value_bitmap)
2779 return gpiod_get_array_value_complex(true, false, array_size,
2780 desc_array, array_info,
2783 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
2786 * gpiod_get_array_value() - read values from an array of GPIOs
2787 * @array_size: number of elements in the descriptor array / value bitmap
2788 * @desc_array: array of GPIO descriptors whose values will be read
2789 * @array_info: information on applicability of fast bitmap processing path
2790 * @value_bitmap: bitmap to store the read values
2792 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2793 * into account. Return 0 in case of success, else an error code.
2795 * This function can be called from contexts where we cannot sleep,
2796 * and it will complain if the GPIO chip functions potentially sleep.
2798 int gpiod_get_array_value(unsigned int array_size,
2799 struct gpio_desc **desc_array,
2800 struct gpio_array *array_info,
2801 unsigned long *value_bitmap)
2805 return gpiod_get_array_value_complex(false, false, array_size,
2806 desc_array, array_info,
2809 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
2812 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
2813 * @desc: gpio descriptor whose state need to be set.
2814 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2816 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
2819 struct gpio_chip *gc = desc->gdev->chip;
2820 int offset = gpio_chip_hwgpio(desc);
2823 ret = gc->direction_input(gc, offset);
2825 ret = gc->direction_output(gc, offset, 0);
2827 set_bit(FLAG_IS_OUT, &desc->flags);
2829 trace_gpio_direction(desc_to_gpio(desc), value, ret);
2832 "%s: Error in set_value for open drain err %d\n",
2837 * _gpio_set_open_source_value() - Set the open source gpio's value.
2838 * @desc: gpio descriptor whose state need to be set.
2839 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2841 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
2844 struct gpio_chip *gc = desc->gdev->chip;
2845 int offset = gpio_chip_hwgpio(desc);
2848 ret = gc->direction_output(gc, offset, 1);
2850 set_bit(FLAG_IS_OUT, &desc->flags);
2852 ret = gc->direction_input(gc, offset);
2854 trace_gpio_direction(desc_to_gpio(desc), !value, ret);
2857 "%s: Error in set_value for open source err %d\n",
2861 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
2863 struct gpio_chip *gc;
2865 gc = desc->gdev->chip;
2866 trace_gpio_value(desc_to_gpio(desc), 0, value);
2867 gc->set(gc, gpio_chip_hwgpio(desc), value);
2871 * set multiple outputs on the same chip;
2872 * use the chip's set_multiple function if available;
2873 * otherwise set the outputs sequentially;
2874 * @chip: the GPIO chip we operate on
2875 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2876 * defines which outputs are to be changed
2877 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2878 * defines the values the outputs specified by mask are to be set to
2880 static void gpio_chip_set_multiple(struct gpio_chip *gc,
2881 unsigned long *mask, unsigned long *bits)
2883 if (gc->set_multiple) {
2884 gc->set_multiple(gc, mask, bits);
2888 /* set outputs if the corresponding mask bit is set */
2889 for_each_set_bit(i, mask, gc->ngpio)
2890 gc->set(gc, i, test_bit(i, bits));
2894 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
2895 unsigned int array_size,
2896 struct gpio_desc **desc_array,
2897 struct gpio_array *array_info,
2898 unsigned long *value_bitmap)
2903 * Validate array_info against desc_array and its size.
2904 * It should immediately follow desc_array if both
2905 * have been obtained from the same gpiod_get_array() call.
2907 if (array_info && array_info->desc == desc_array &&
2908 array_size <= array_info->size &&
2909 (void *)array_info == desc_array + array_info->size) {
2911 WARN_ON(array_info->chip->can_sleep);
2913 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2914 bitmap_xor(value_bitmap, value_bitmap,
2915 array_info->invert_mask, array_size);
2917 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
2920 i = find_first_zero_bit(array_info->set_mask, array_size);
2921 if (i == array_size)
2927 while (i < array_size) {
2928 struct gpio_chip *gc = desc_array[i]->gdev->chip;
2929 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
2930 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
2931 unsigned long *mask, *bits;
2934 if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
2935 mask = fastpath_mask;
2936 bits = fastpath_bits;
2938 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
2940 mask = bitmap_alloc(gc->ngpio, flags);
2944 bits = bitmap_alloc(gc->ngpio, flags);
2951 bitmap_zero(mask, gc->ngpio);
2954 WARN_ON(gc->can_sleep);
2957 struct gpio_desc *desc = desc_array[i];
2958 int hwgpio = gpio_chip_hwgpio(desc);
2959 int value = test_bit(i, value_bitmap);
2962 * Pins applicable for fast input but not for
2963 * fast output processing may have been already
2964 * inverted inside the fast path, skip them.
2966 if (!raw && !(array_info &&
2967 test_bit(i, array_info->invert_mask)) &&
2968 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2970 trace_gpio_value(desc_to_gpio(desc), 0, value);
2972 * collect all normal outputs belonging to the same chip
2973 * open drain and open source outputs are set individually
2975 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
2976 gpio_set_open_drain_value_commit(desc, value);
2977 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
2978 gpio_set_open_source_value_commit(desc, value);
2980 __set_bit(hwgpio, mask);
2981 __assign_bit(hwgpio, bits, value);
2987 i = find_next_zero_bit(array_info->set_mask,
2989 } while ((i < array_size) &&
2990 (desc_array[i]->gdev->chip == gc));
2991 /* push collected bits to outputs */
2993 gpio_chip_set_multiple(gc, mask, bits);
2995 if (mask != fastpath_mask)
2997 if (bits != fastpath_bits)
3004 * gpiod_set_raw_value() - assign a gpio's raw value
3005 * @desc: gpio whose value will be assigned
3006 * @value: value to assign
3008 * Set the raw value of the GPIO, i.e. the value of its physical line without
3009 * regard for its ACTIVE_LOW status.
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_raw_value(struct gpio_desc *desc, int value)
3016 VALIDATE_DESC_VOID(desc);
3017 /* Should be using gpiod_set_raw_value_cansleep() */
3018 WARN_ON(desc->gdev->chip->can_sleep);
3019 gpiod_set_raw_value_commit(desc, value);
3021 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3024 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3025 * @desc: the descriptor to set the value on
3026 * @value: value to set
3028 * This sets the value of a GPIO line backing a descriptor, applying
3029 * different semantic quirks like active low and open drain/source
3032 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3034 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3036 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3037 gpio_set_open_drain_value_commit(desc, value);
3038 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3039 gpio_set_open_source_value_commit(desc, value);
3041 gpiod_set_raw_value_commit(desc, value);
3045 * gpiod_set_value() - assign a gpio's value
3046 * @desc: gpio whose value will be assigned
3047 * @value: value to assign
3049 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3050 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3052 * This function can be called from contexts where we cannot sleep, and will
3053 * complain if the GPIO chip functions potentially sleep.
3055 void gpiod_set_value(struct gpio_desc *desc, int value)
3057 VALIDATE_DESC_VOID(desc);
3058 /* Should be using gpiod_set_value_cansleep() */
3059 WARN_ON(desc->gdev->chip->can_sleep);
3060 gpiod_set_value_nocheck(desc, value);
3062 EXPORT_SYMBOL_GPL(gpiod_set_value);
3065 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3066 * @array_size: number of elements in the descriptor array / value bitmap
3067 * @desc_array: array of GPIO descriptors whose values will be assigned
3068 * @array_info: information on applicability of fast bitmap processing path
3069 * @value_bitmap: bitmap of values to assign
3071 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3072 * without regard for their ACTIVE_LOW status.
3074 * This function can be called from contexts where we cannot sleep, and will
3075 * complain if the GPIO chip functions potentially sleep.
3077 int gpiod_set_raw_array_value(unsigned int array_size,
3078 struct gpio_desc **desc_array,
3079 struct gpio_array *array_info,
3080 unsigned long *value_bitmap)
3084 return gpiod_set_array_value_complex(true, false, array_size,
3085 desc_array, array_info, value_bitmap);
3087 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3090 * gpiod_set_array_value() - assign values to an array of GPIOs
3091 * @array_size: number of elements in the descriptor array / value bitmap
3092 * @desc_array: array of GPIO descriptors whose values will be assigned
3093 * @array_info: information on applicability of fast bitmap processing path
3094 * @value_bitmap: bitmap of values to assign
3096 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3099 * This function can be called from contexts where we cannot sleep, and will
3100 * complain if the GPIO chip functions potentially sleep.
3102 int gpiod_set_array_value(unsigned int array_size,
3103 struct gpio_desc **desc_array,
3104 struct gpio_array *array_info,
3105 unsigned long *value_bitmap)
3109 return gpiod_set_array_value_complex(false, false, array_size,
3110 desc_array, array_info,
3113 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3116 * gpiod_cansleep() - report whether gpio value access may sleep
3117 * @desc: gpio to check
3120 int gpiod_cansleep(const struct gpio_desc *desc)
3122 VALIDATE_DESC(desc);
3123 return desc->gdev->chip->can_sleep;
3125 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3128 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3129 * @desc: gpio to set the consumer name on
3130 * @name: the new consumer name
3132 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3134 VALIDATE_DESC(desc);
3136 name = kstrdup_const(name, GFP_KERNEL);
3141 kfree_const(desc->label);
3142 desc_set_label(desc, name);
3146 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3149 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3150 * @desc: gpio whose IRQ will be returned (already requested)
3152 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3155 int gpiod_to_irq(const struct gpio_desc *desc)
3157 struct gpio_chip *gc;
3161 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3162 * requires this function to not return zero on an invalid descriptor
3163 * but rather a negative error number.
3165 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3168 gc = desc->gdev->chip;
3169 offset = gpio_chip_hwgpio(desc);
3171 int retirq = gc->to_irq(gc, offset);
3173 /* Zero means NO_IRQ */
3179 #ifdef CONFIG_GPIOLIB_IRQCHIP
3182 * Avoid race condition with other code, which tries to lookup
3183 * an IRQ before the irqchip has been properly registered,
3184 * i.e. while gpiochip is still being brought up.
3186 return -EPROBE_DEFER;
3191 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3194 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3195 * @gc: the chip the GPIO to lock belongs to
3196 * @offset: the offset of the GPIO to lock as IRQ
3198 * This is used directly by GPIO drivers that want to lock down
3199 * a certain GPIO line to be used for IRQs.
3201 int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
3203 struct gpio_desc *desc;
3205 desc = gpiochip_get_desc(gc, offset);
3207 return PTR_ERR(desc);
3210 * If it's fast: flush the direction setting if something changed
3213 if (!gc->can_sleep && gc->get_direction) {
3214 int dir = gpiod_get_direction(desc);
3217 chip_err(gc, "%s: cannot get GPIO direction\n",
3223 /* To be valid for IRQ the line needs to be input or open drain */
3224 if (test_bit(FLAG_IS_OUT, &desc->flags) &&
3225 !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
3227 "%s: tried to flag a GPIO set as output for IRQ\n",
3232 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3233 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3236 * If the consumer has not set up a label (such as when the
3237 * IRQ is referenced from .to_irq()) we set up a label here
3238 * so it is clear this is used as an interrupt.
3241 desc_set_label(desc, "interrupt");
3245 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3248 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3249 * @gc: the chip the GPIO to lock belongs to
3250 * @offset: the offset of the GPIO to lock as IRQ
3252 * This is used directly by GPIO drivers that want to indicate
3253 * that a certain GPIO is no longer used exclusively for IRQ.
3255 void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
3257 struct gpio_desc *desc;
3259 desc = gpiochip_get_desc(gc, offset);
3263 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3264 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3266 /* If we only had this marking, erase it */
3267 if (desc->label && !strcmp(desc->label, "interrupt"))
3268 desc_set_label(desc, NULL);
3270 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3272 void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
3274 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3276 if (!IS_ERR(desc) &&
3277 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3278 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3280 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3282 void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
3284 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3286 if (!IS_ERR(desc) &&
3287 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3289 * We must not be output when using IRQ UNLESS we are
3292 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
3293 !test_bit(FLAG_OPEN_DRAIN, &desc->flags));
3294 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3297 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3299 bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
3301 if (offset >= gc->ngpio)
3304 return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
3306 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3308 int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
3312 if (!try_module_get(gc->gpiodev->owner))
3315 ret = gpiochip_lock_as_irq(gc, offset);
3317 chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
3318 module_put(gc->gpiodev->owner);
3323 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3325 void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
3327 gpiochip_unlock_as_irq(gc, offset);
3328 module_put(gc->gpiodev->owner);
3330 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3332 bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
3334 if (offset >= gc->ngpio)
3337 return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
3339 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3341 bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
3343 if (offset >= gc->ngpio)
3346 return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
3348 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3350 bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
3352 if (offset >= gc->ngpio)
3355 return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
3357 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3360 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3361 * @desc: gpio whose value will be returned
3363 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3364 * its ACTIVE_LOW status, or negative errno on failure.
3366 * This function is to be called from contexts that can sleep.
3368 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3370 might_sleep_if(extra_checks);
3371 VALIDATE_DESC(desc);
3372 return gpiod_get_raw_value_commit(desc);
3374 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3377 * gpiod_get_value_cansleep() - return a gpio's value
3378 * @desc: gpio whose value will be returned
3380 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3381 * account, or negative errno on failure.
3383 * This function is to be called from contexts that can sleep.
3385 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3389 might_sleep_if(extra_checks);
3390 VALIDATE_DESC(desc);
3391 value = gpiod_get_raw_value_commit(desc);
3395 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3400 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3403 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3404 * @array_size: number of elements in the descriptor array / value bitmap
3405 * @desc_array: array of GPIO descriptors whose values will be read
3406 * @array_info: information on applicability of fast bitmap processing path
3407 * @value_bitmap: bitmap to store the read values
3409 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3410 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3411 * else an error code.
3413 * This function is to be called from contexts that can sleep.
3415 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3416 struct gpio_desc **desc_array,
3417 struct gpio_array *array_info,
3418 unsigned long *value_bitmap)
3420 might_sleep_if(extra_checks);
3423 return gpiod_get_array_value_complex(true, true, array_size,
3424 desc_array, array_info,
3427 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3430 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3431 * @array_size: number of elements in the descriptor array / value bitmap
3432 * @desc_array: array of GPIO descriptors whose values will be read
3433 * @array_info: information on applicability of fast bitmap processing path
3434 * @value_bitmap: bitmap to store the read values
3436 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3437 * into account. Return 0 in case of success, else an error code.
3439 * This function is to be called from contexts that can sleep.
3441 int gpiod_get_array_value_cansleep(unsigned int array_size,
3442 struct gpio_desc **desc_array,
3443 struct gpio_array *array_info,
3444 unsigned long *value_bitmap)
3446 might_sleep_if(extra_checks);
3449 return gpiod_get_array_value_complex(false, true, array_size,
3450 desc_array, array_info,
3453 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3456 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3457 * @desc: gpio whose value will be assigned
3458 * @value: value to assign
3460 * Set the raw value of the GPIO, i.e. the value of its physical line without
3461 * regard for its ACTIVE_LOW status.
3463 * This function is to be called from contexts that can sleep.
3465 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3467 might_sleep_if(extra_checks);
3468 VALIDATE_DESC_VOID(desc);
3469 gpiod_set_raw_value_commit(desc, value);
3471 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3474 * gpiod_set_value_cansleep() - assign a gpio's value
3475 * @desc: gpio whose value will be assigned
3476 * @value: value to assign
3478 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3481 * This function is to be called from contexts that can sleep.
3483 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3485 might_sleep_if(extra_checks);
3486 VALIDATE_DESC_VOID(desc);
3487 gpiod_set_value_nocheck(desc, value);
3489 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3492 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3493 * @array_size: number of elements in the descriptor array / value bitmap
3494 * @desc_array: array of GPIO descriptors whose values will be assigned
3495 * @array_info: information on applicability of fast bitmap processing path
3496 * @value_bitmap: bitmap of values to assign
3498 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3499 * without regard for their ACTIVE_LOW status.
3501 * This function is to be called from contexts that can sleep.
3503 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3504 struct gpio_desc **desc_array,
3505 struct gpio_array *array_info,
3506 unsigned long *value_bitmap)
3508 might_sleep_if(extra_checks);
3511 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3512 array_info, value_bitmap);
3514 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3517 * gpiod_add_lookup_tables() - register GPIO device consumers
3518 * @tables: list of tables of consumers to register
3519 * @n: number of tables in the list
3521 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3525 mutex_lock(&gpio_lookup_lock);
3527 for (i = 0; i < n; i++)
3528 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3530 mutex_unlock(&gpio_lookup_lock);
3534 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3535 * @array_size: number of elements in the descriptor array / value bitmap
3536 * @desc_array: array of GPIO descriptors whose values will be assigned
3537 * @array_info: information on applicability of fast bitmap processing path
3538 * @value_bitmap: bitmap of values to assign
3540 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3543 * This function is to be called from contexts that can sleep.
3545 int gpiod_set_array_value_cansleep(unsigned int array_size,
3546 struct gpio_desc **desc_array,
3547 struct gpio_array *array_info,
3548 unsigned long *value_bitmap)
3550 might_sleep_if(extra_checks);
3553 return gpiod_set_array_value_complex(false, true, array_size,
3554 desc_array, array_info,
3557 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3560 * gpiod_add_lookup_table() - register GPIO device consumers
3561 * @table: table of consumers to register
3563 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3565 gpiod_add_lookup_tables(&table, 1);
3567 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3570 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3571 * @table: table of consumers to unregister
3573 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3575 /* Nothing to remove */
3579 mutex_lock(&gpio_lookup_lock);
3581 list_del(&table->list);
3583 mutex_unlock(&gpio_lookup_lock);
3585 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3588 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
3589 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
3591 void gpiod_add_hogs(struct gpiod_hog *hogs)
3593 struct gpio_chip *gc;
3594 struct gpiod_hog *hog;
3596 mutex_lock(&gpio_machine_hogs_mutex);
3598 for (hog = &hogs[0]; hog->chip_label; hog++) {
3599 list_add_tail(&hog->list, &gpio_machine_hogs);
3602 * The chip may have been registered earlier, so check if it
3603 * exists and, if so, try to hog the line now.
3605 gc = find_chip_by_name(hog->chip_label);
3607 gpiochip_machine_hog(gc, hog);
3610 mutex_unlock(&gpio_machine_hogs_mutex);
3612 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
3614 void gpiod_remove_hogs(struct gpiod_hog *hogs)
3616 struct gpiod_hog *hog;
3618 mutex_lock(&gpio_machine_hogs_mutex);
3619 for (hog = &hogs[0]; hog->chip_label; hog++)
3620 list_del(&hog->list);
3621 mutex_unlock(&gpio_machine_hogs_mutex);
3623 EXPORT_SYMBOL_GPL(gpiod_remove_hogs);
3625 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3627 const char *dev_id = dev ? dev_name(dev) : NULL;
3628 struct gpiod_lookup_table *table;
3630 mutex_lock(&gpio_lookup_lock);
3632 list_for_each_entry(table, &gpio_lookup_list, list) {
3633 if (table->dev_id && dev_id) {
3635 * Valid strings on both ends, must be identical to have
3638 if (!strcmp(table->dev_id, dev_id))
3642 * One of the pointers is NULL, so both must be to have
3645 if (dev_id == table->dev_id)
3652 mutex_unlock(&gpio_lookup_lock);
3656 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3657 unsigned int idx, unsigned long *flags)
3659 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3660 struct gpiod_lookup_table *table;
3661 struct gpiod_lookup *p;
3663 table = gpiod_find_lookup_table(dev);
3667 for (p = &table->table[0]; p->key; p++) {
3668 struct gpio_chip *gc;
3670 /* idx must always match exactly */
3674 /* If the lookup entry has a con_id, require exact match */
3675 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3678 if (p->chip_hwnum == U16_MAX) {
3679 desc = gpio_name_to_desc(p->key);
3685 dev_warn(dev, "cannot find GPIO line %s, deferring\n",
3687 return ERR_PTR(-EPROBE_DEFER);
3690 gc = find_chip_by_name(p->key);
3694 * As the lookup table indicates a chip with
3695 * p->key should exist, assume it may
3696 * still appear later and let the interested
3697 * consumer be probed again or let the Deferred
3698 * Probe infrastructure handle the error.
3700 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
3702 return ERR_PTR(-EPROBE_DEFER);
3705 if (gc->ngpio <= p->chip_hwnum) {
3707 "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
3708 idx, p->chip_hwnum, gc->ngpio - 1,
3710 return ERR_PTR(-EINVAL);
3713 desc = gpiochip_get_desc(gc, p->chip_hwnum);
3722 static int platform_gpio_count(struct device *dev, const char *con_id)
3724 struct gpiod_lookup_table *table;
3725 struct gpiod_lookup *p;
3726 unsigned int count = 0;
3728 table = gpiod_find_lookup_table(dev);
3732 for (p = &table->table[0]; p->key; p++) {
3733 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3734 (!con_id && !p->con_id))
3744 * fwnode_gpiod_get_index - obtain a GPIO from firmware node
3745 * @fwnode: handle of the firmware node
3746 * @con_id: function within the GPIO consumer
3747 * @index: index of the GPIO to obtain for the consumer
3748 * @flags: GPIO initialization flags
3749 * @label: label to attach to the requested GPIO
3751 * This function can be used for drivers that get their configuration
3752 * from opaque firmware.
3754 * The function properly finds the corresponding GPIO using whatever is the
3755 * underlying firmware interface and then makes sure that the GPIO
3756 * descriptor is requested before it is returned to the caller.
3759 * On successful request the GPIO pin is configured in accordance with
3762 * In case of error an ERR_PTR() is returned.
3764 struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
3765 const char *con_id, int index,
3766 enum gpiod_flags flags,
3769 struct gpio_desc *desc;
3770 char prop_name[32]; /* 32 is max size of property name */
3773 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3775 snprintf(prop_name, sizeof(prop_name), "%s-%s",
3776 con_id, gpio_suffixes[i]);
3778 snprintf(prop_name, sizeof(prop_name), "%s",
3781 desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
3783 if (!gpiod_not_found(desc))
3789 EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
3792 * gpiod_count - return the number of GPIOs associated with a device / function
3793 * or -ENOENT if no GPIO has been assigned to the requested function
3794 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3795 * @con_id: function within the GPIO consumer
3797 int gpiod_count(struct device *dev, const char *con_id)
3799 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
3800 int count = -ENOENT;
3802 if (is_of_node(fwnode))
3803 count = of_gpio_get_count(dev, con_id);
3804 else if (is_acpi_node(fwnode))
3805 count = acpi_gpio_count(dev, con_id);
3808 count = platform_gpio_count(dev, con_id);
3812 EXPORT_SYMBOL_GPL(gpiod_count);
3815 * gpiod_get - obtain a GPIO for a given GPIO function
3816 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3817 * @con_id: function within the GPIO consumer
3818 * @flags: optional GPIO initialization flags
3820 * Return the GPIO descriptor corresponding to the function con_id of device
3821 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3822 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3824 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3825 enum gpiod_flags flags)
3827 return gpiod_get_index(dev, con_id, 0, flags);
3829 EXPORT_SYMBOL_GPL(gpiod_get);
3832 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3833 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3834 * @con_id: function within the GPIO consumer
3835 * @flags: optional GPIO initialization flags
3837 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3838 * the requested function it will return NULL. This is convenient for drivers
3839 * that need to handle optional GPIOs.
3841 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3843 enum gpiod_flags flags)
3845 return gpiod_get_index_optional(dev, con_id, 0, flags);
3847 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3851 * gpiod_configure_flags - helper function to configure a given GPIO
3852 * @desc: gpio whose value will be assigned
3853 * @con_id: function within the GPIO consumer
3854 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
3855 * of_find_gpio() or of_get_gpio_hog()
3856 * @dflags: gpiod_flags - optional GPIO initialization flags
3858 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3859 * requested function and/or index, or another IS_ERR() code if an error
3860 * occurred while trying to acquire the GPIO.
3862 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3863 unsigned long lflags, enum gpiod_flags dflags)
3867 if (lflags & GPIO_ACTIVE_LOW)
3868 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3870 if (lflags & GPIO_OPEN_DRAIN)
3871 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3872 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
3874 * This enforces open drain mode from the consumer side.
3875 * This is necessary for some busses like I2C, but the lookup
3876 * should *REALLY* have specified them as open drain in the
3877 * first place, so print a little warning here.
3879 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3881 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
3884 if (lflags & GPIO_OPEN_SOURCE)
3885 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3887 if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
3889 "both pull-up and pull-down enabled, invalid configuration\n");
3893 if (lflags & GPIO_PULL_UP)
3894 set_bit(FLAG_PULL_UP, &desc->flags);
3895 else if (lflags & GPIO_PULL_DOWN)
3896 set_bit(FLAG_PULL_DOWN, &desc->flags);
3898 ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
3902 /* No particular flag request, return here... */
3903 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3904 gpiod_dbg(desc, "no flags found for %s\n", con_id);
3909 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3910 ret = gpiod_direction_output(desc,
3911 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3913 ret = gpiod_direction_input(desc);
3919 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3920 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3921 * @con_id: function within the GPIO consumer
3922 * @idx: index of the GPIO to obtain in the consumer
3923 * @flags: optional GPIO initialization flags
3925 * This variant of gpiod_get() allows to access GPIOs other than the first
3926 * defined one for functions that define several GPIOs.
3928 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3929 * requested function and/or index, or another IS_ERR() code if an error
3930 * occurred while trying to acquire the GPIO.
3932 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3935 enum gpiod_flags flags)
3937 unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
3938 struct gpio_desc *desc = NULL;
3940 /* Maybe we have a device name, maybe not */
3941 const char *devname = dev ? dev_name(dev) : "?";
3942 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
3944 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3946 /* Using device tree? */
3947 if (is_of_node(fwnode)) {
3948 dev_dbg(dev, "using device tree for GPIO lookup\n");
3949 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3950 } else if (is_acpi_node(fwnode)) {
3951 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3952 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
3956 * Either we are not using DT or ACPI, or their lookup did not return
3957 * a result. In that case, use platform lookup as a fallback.
3959 if (!desc || gpiod_not_found(desc)) {
3960 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3961 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3965 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
3970 * If a connection label was passed use that, else attempt to use
3971 * the device name as label
3973 ret = gpiod_request(desc, con_id ?: devname);
3975 if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
3976 return ERR_PTR(ret);
3979 * This happens when there are several consumers for
3980 * the same GPIO line: we just return here without
3981 * further initialization. It is a bit of a hack.
3982 * This is necessary to support fixed regulators.
3984 * FIXME: Make this more sane and safe.
3986 dev_info(dev, "nonexclusive access to GPIO for %s\n", con_id ?: devname);
3990 ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3992 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3994 return ERR_PTR(ret);
3997 blocking_notifier_call_chain(&desc->gdev->notifier,
3998 GPIOLINE_CHANGED_REQUESTED, desc);
4002 EXPORT_SYMBOL_GPL(gpiod_get_index);
4005 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
4006 * @fwnode: handle of the firmware node
4007 * @propname: name of the firmware property representing the GPIO
4008 * @index: index of the GPIO to obtain for the consumer
4009 * @dflags: GPIO initialization flags
4010 * @label: label to attach to the requested GPIO
4012 * This function can be used for drivers that get their configuration
4013 * from opaque firmware.
4015 * The function properly finds the corresponding GPIO using whatever is the
4016 * underlying firmware interface and then makes sure that the GPIO
4017 * descriptor is requested before it is returned to the caller.
4020 * On successful request the GPIO pin is configured in accordance with
4023 * In case of error an ERR_PTR() is returned.
4025 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
4026 const char *propname, int index,
4027 enum gpiod_flags dflags,
4030 unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4031 struct gpio_desc *desc = ERR_PTR(-ENODEV);
4034 if (is_of_node(fwnode)) {
4035 desc = gpiod_get_from_of_node(to_of_node(fwnode),
4040 } else if (is_acpi_node(fwnode)) {
4041 struct acpi_gpio_info info;
4043 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4047 acpi_gpio_update_gpiod_flags(&dflags, &info);
4048 acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
4050 return ERR_PTR(-EINVAL);
4052 /* Currently only ACPI takes this path */
4053 ret = gpiod_request(desc, label);
4055 return ERR_PTR(ret);
4057 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4060 return ERR_PTR(ret);
4063 blocking_notifier_call_chain(&desc->gdev->notifier,
4064 GPIOLINE_CHANGED_REQUESTED, desc);
4068 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4071 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4073 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4074 * @con_id: function within the GPIO consumer
4075 * @index: index of the GPIO to obtain in the consumer
4076 * @flags: optional GPIO initialization flags
4078 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4079 * specified index was assigned to the requested function it will return NULL.
4080 * This is convenient for drivers that need to handle optional GPIOs.
4082 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4085 enum gpiod_flags flags)
4087 struct gpio_desc *desc;
4089 desc = gpiod_get_index(dev, con_id, index, flags);
4090 if (gpiod_not_found(desc))
4095 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4098 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4099 * @desc: gpio whose value will be assigned
4100 * @name: gpio line name
4101 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4102 * of_find_gpio() or of_get_gpio_hog()
4103 * @dflags: gpiod_flags - optional GPIO initialization flags
4105 int gpiod_hog(struct gpio_desc *desc, const char *name,
4106 unsigned long lflags, enum gpiod_flags dflags)
4108 struct gpio_chip *gc;
4109 struct gpio_desc *local_desc;
4113 gc = gpiod_to_chip(desc);
4114 hwnum = gpio_chip_hwgpio(desc);
4116 local_desc = gpiochip_request_own_desc(gc, hwnum, name,
4118 if (IS_ERR(local_desc)) {
4119 ret = PTR_ERR(local_desc);
4120 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4121 name, gc->label, hwnum, ret);
4125 /* Mark GPIO as hogged so it can be identified and removed later */
4126 set_bit(FLAG_IS_HOGGED, &desc->flags);
4128 gpiod_info(desc, "hogged as %s%s\n",
4129 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4130 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
4131 (dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : "");
4137 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4138 * @gc: gpio chip to act on
4140 static void gpiochip_free_hogs(struct gpio_chip *gc)
4142 struct gpio_desc *desc;
4145 for_each_gpio_desc_with_flag(id, gc, desc, FLAG_IS_HOGGED)
4146 gpiochip_free_own_desc(desc);
4150 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4151 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4152 * @con_id: function within the GPIO consumer
4153 * @flags: optional GPIO initialization flags
4155 * This function acquires all the GPIOs defined under a given function.
4157 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4158 * no GPIO has been assigned to the requested function, or another IS_ERR()
4159 * code if an error occurred while trying to acquire the GPIOs.
4161 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4163 enum gpiod_flags flags)
4165 struct gpio_desc *desc;
4166 struct gpio_descs *descs;
4167 struct gpio_array *array_info = NULL;
4168 struct gpio_chip *gc;
4169 int count, bitmap_size;
4171 count = gpiod_count(dev, con_id);
4173 return ERR_PTR(count);
4175 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4177 return ERR_PTR(-ENOMEM);
4179 for (descs->ndescs = 0; descs->ndescs < count; ) {
4180 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4182 gpiod_put_array(descs);
4183 return ERR_CAST(desc);
4186 descs->desc[descs->ndescs] = desc;
4188 gc = gpiod_to_chip(desc);
4190 * If pin hardware number of array member 0 is also 0, select
4191 * its chip as a candidate for fast bitmap processing path.
4193 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4194 struct gpio_descs *array;
4196 bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?
4199 array = kzalloc(struct_size(descs, desc, count) +
4200 struct_size(array_info, invert_mask,
4201 3 * bitmap_size), GFP_KERNEL);
4203 gpiod_put_array(descs);
4204 return ERR_PTR(-ENOMEM);
4207 memcpy(array, descs,
4208 struct_size(descs, desc, descs->ndescs + 1));
4212 array_info = (void *)(descs->desc + count);
4213 array_info->get_mask = array_info->invert_mask +
4215 array_info->set_mask = array_info->get_mask +
4218 array_info->desc = descs->desc;
4219 array_info->size = count;
4220 array_info->chip = gc;
4221 bitmap_set(array_info->get_mask, descs->ndescs,
4222 count - descs->ndescs);
4223 bitmap_set(array_info->set_mask, descs->ndescs,
4224 count - descs->ndescs);
4225 descs->info = array_info;
4227 /* Unmark array members which don't belong to the 'fast' chip */
4228 if (array_info && array_info->chip != gc) {
4229 __clear_bit(descs->ndescs, array_info->get_mask);
4230 __clear_bit(descs->ndescs, array_info->set_mask);
4233 * Detect array members which belong to the 'fast' chip
4234 * but their pins are not in hardware order.
4236 else if (array_info &&
4237 gpio_chip_hwgpio(desc) != descs->ndescs) {
4239 * Don't use fast path if all array members processed so
4240 * far belong to the same chip as this one but its pin
4241 * hardware number is different from its array index.
4243 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4246 __clear_bit(descs->ndescs,
4247 array_info->get_mask);
4248 __clear_bit(descs->ndescs,
4249 array_info->set_mask);
4251 } else if (array_info) {
4252 /* Exclude open drain or open source from fast output */
4253 if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||
4254 gpiochip_line_is_open_source(gc, descs->ndescs))
4255 __clear_bit(descs->ndescs,
4256 array_info->set_mask);
4257 /* Identify 'fast' pins which require invertion */
4258 if (gpiod_is_active_low(desc))
4259 __set_bit(descs->ndescs,
4260 array_info->invert_mask);
4267 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4268 array_info->chip->label, array_info->size,
4269 *array_info->get_mask, *array_info->set_mask,
4270 *array_info->invert_mask);
4273 EXPORT_SYMBOL_GPL(gpiod_get_array);
4276 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4278 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4279 * @con_id: function within the GPIO consumer
4280 * @flags: optional GPIO initialization flags
4282 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4283 * assigned to the requested function it will return NULL.
4285 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4287 enum gpiod_flags flags)
4289 struct gpio_descs *descs;
4291 descs = gpiod_get_array(dev, con_id, flags);
4292 if (gpiod_not_found(descs))
4297 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4300 * gpiod_put - dispose of a GPIO descriptor
4301 * @desc: GPIO descriptor to dispose of
4303 * No descriptor can be used after gpiod_put() has been called on it.
4305 void gpiod_put(struct gpio_desc *desc)
4310 EXPORT_SYMBOL_GPL(gpiod_put);
4313 * gpiod_put_array - dispose of multiple GPIO descriptors
4314 * @descs: struct gpio_descs containing an array of descriptors
4316 void gpiod_put_array(struct gpio_descs *descs)
4320 for (i = 0; i < descs->ndescs; i++)
4321 gpiod_put(descs->desc[i]);
4325 EXPORT_SYMBOL_GPL(gpiod_put_array);
4328 static int gpio_bus_match(struct device *dev, struct device_driver *drv)
4330 struct fwnode_handle *fwnode = dev_fwnode(dev);
4333 * Only match if the fwnode doesn't already have a proper struct device
4336 if (fwnode && fwnode->dev != dev)
4341 static int gpio_stub_drv_probe(struct device *dev)
4344 * The DT node of some GPIO chips have a "compatible" property, but
4345 * never have a struct device added and probed by a driver to register
4346 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
4347 * the consumers of the GPIO chip to get probe deferred forever because
4348 * they will be waiting for a device associated with the GPIO chip
4349 * firmware node to get added and bound to a driver.
4351 * To allow these consumers to probe, we associate the struct
4352 * gpio_device of the GPIO chip with the firmware node and then simply
4353 * bind it to this stub driver.
4358 static struct device_driver gpio_stub_drv = {
4359 .name = "gpio_stub_drv",
4360 .bus = &gpio_bus_type,
4361 .probe = gpio_stub_drv_probe,
4364 static int __init gpiolib_dev_init(void)
4368 /* Register GPIO sysfs bus */
4369 ret = bus_register(&gpio_bus_type);
4371 pr_err("gpiolib: could not register GPIO bus type\n");
4375 ret = driver_register(&gpio_stub_drv);
4377 pr_err("gpiolib: could not register GPIO stub driver\n");
4378 bus_unregister(&gpio_bus_type);
4382 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
4384 pr_err("gpiolib: failed to allocate char dev region\n");
4385 driver_unregister(&gpio_stub_drv);
4386 bus_unregister(&gpio_bus_type);
4390 gpiolib_initialized = true;
4391 gpiochip_setup_devs();
4393 #if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
4394 WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
4395 #endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
4399 core_initcall(gpiolib_dev_init);
4401 #ifdef CONFIG_DEBUG_FS
4403 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4406 struct gpio_chip *gc = gdev->chip;
4407 unsigned gpio = gdev->base;
4408 struct gpio_desc *gdesc = &gdev->descs[0];
4413 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4414 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4416 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4422 gpiod_get_direction(gdesc);
4423 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4424 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4425 active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
4426 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
4427 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4428 is_out ? "out" : "in ",
4429 gc->get ? (gc->get(gc, i) ? "hi" : "lo") : "? ",
4430 is_irq ? "IRQ " : "",
4431 active_low ? "ACTIVE LOW" : "");
4432 seq_printf(s, "\n");
4436 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4438 unsigned long flags;
4439 struct gpio_device *gdev = NULL;
4440 loff_t index = *pos;
4444 spin_lock_irqsave(&gpio_lock, flags);
4445 list_for_each_entry(gdev, &gpio_devices, list)
4447 spin_unlock_irqrestore(&gpio_lock, flags);
4450 spin_unlock_irqrestore(&gpio_lock, flags);
4455 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4457 unsigned long flags;
4458 struct gpio_device *gdev = v;
4461 spin_lock_irqsave(&gpio_lock, flags);
4462 if (list_is_last(&gdev->list, &gpio_devices))
4465 ret = list_first_entry(&gdev->list, struct gpio_device, list);
4466 spin_unlock_irqrestore(&gpio_lock, flags);
4474 static void gpiolib_seq_stop(struct seq_file *s, void *v)
4478 static int gpiolib_seq_show(struct seq_file *s, void *v)
4480 struct gpio_device *gdev = v;
4481 struct gpio_chip *gc = gdev->chip;
4482 struct device *parent;
4485 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4486 dev_name(&gdev->dev));
4490 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4491 dev_name(&gdev->dev),
4492 gdev->base, gdev->base + gdev->ngpio - 1);
4493 parent = gc->parent;
4495 seq_printf(s, ", parent: %s/%s",
4496 parent->bus ? parent->bus->name : "no-bus",
4499 seq_printf(s, ", %s", gc->label);
4501 seq_printf(s, ", can sleep");
4502 seq_printf(s, ":\n");
4505 gc->dbg_show(s, gc);
4507 gpiolib_dbg_show(s, gdev);
4512 static const struct seq_operations gpiolib_sops = {
4513 .start = gpiolib_seq_start,
4514 .next = gpiolib_seq_next,
4515 .stop = gpiolib_seq_stop,
4516 .show = gpiolib_seq_show,
4518 DEFINE_SEQ_ATTRIBUTE(gpiolib);
4520 static int __init gpiolib_debugfs_init(void)
4522 /* /sys/kernel/debug/gpio */
4523 debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);
4526 subsys_initcall(gpiolib_debugfs_init);
4528 #endif /* DEBUG_FS */