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 #define dont_test_bit(b,d) (0)
57 /* Device and char device-related information */
58 static DEFINE_IDA(gpio_ida);
59 static dev_t gpio_devt;
60 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
61 static int gpio_bus_match(struct device *dev, struct device_driver *drv);
62 static struct bus_type gpio_bus_type = {
64 .match = gpio_bus_match,
68 * Number of GPIOs to use for the fast path in set array
70 #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
72 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
73 * While any GPIO is requested, its gpio_chip is not removable;
74 * each GPIO's "requested" flag serves as a lock and refcount.
76 DEFINE_SPINLOCK(gpio_lock);
78 static DEFINE_MUTEX(gpio_lookup_lock);
79 static LIST_HEAD(gpio_lookup_list);
80 LIST_HEAD(gpio_devices);
82 static DEFINE_MUTEX(gpio_machine_hogs_mutex);
83 static LIST_HEAD(gpio_machine_hogs);
85 static void gpiochip_free_hogs(struct gpio_chip *gc);
86 static int gpiochip_add_irqchip(struct gpio_chip *gc,
87 struct lock_class_key *lock_key,
88 struct lock_class_key *request_key);
89 static void gpiochip_irqchip_remove(struct gpio_chip *gc);
90 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc);
91 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc);
92 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc);
94 static bool gpiolib_initialized;
96 static inline void desc_set_label(struct gpio_desc *d, const char *label)
102 * gpio_to_desc - Convert a GPIO number to its descriptor
103 * @gpio: global GPIO number
106 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
107 * with the given number exists in the system.
109 struct gpio_desc *gpio_to_desc(unsigned gpio)
111 struct gpio_device *gdev;
114 spin_lock_irqsave(&gpio_lock, flags);
116 list_for_each_entry(gdev, &gpio_devices, list) {
117 if (gdev->base <= gpio &&
118 gdev->base + gdev->ngpio > gpio) {
119 spin_unlock_irqrestore(&gpio_lock, flags);
120 return &gdev->descs[gpio - gdev->base];
124 spin_unlock_irqrestore(&gpio_lock, flags);
126 if (!gpio_is_valid(gpio))
127 pr_warn("invalid GPIO %d\n", gpio);
131 EXPORT_SYMBOL_GPL(gpio_to_desc);
134 * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
135 * hardware number for this chip
137 * @hwnum: hardware number of the GPIO for this chip
140 * A pointer to the GPIO descriptor or ``ERR_PTR(-EINVAL)`` if no GPIO exists
141 * in the given chip for the specified hardware number.
143 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc,
146 struct gpio_device *gdev = gc->gpiodev;
148 if (hwnum >= gdev->ngpio)
149 return ERR_PTR(-EINVAL);
151 return &gdev->descs[hwnum];
153 EXPORT_SYMBOL_GPL(gpiochip_get_desc);
156 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
157 * @desc: GPIO descriptor
159 * This should disappear in the future but is needed since we still
160 * use GPIO numbers for error messages and sysfs nodes.
163 * The global GPIO number for the GPIO specified by its descriptor.
165 int desc_to_gpio(const struct gpio_desc *desc)
167 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
169 EXPORT_SYMBOL_GPL(desc_to_gpio);
173 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
174 * @desc: descriptor to return the chip of
176 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
178 if (!desc || !desc->gdev)
180 return desc->gdev->chip;
182 EXPORT_SYMBOL_GPL(gpiod_to_chip);
184 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
185 static int gpiochip_find_base(int ngpio)
187 struct gpio_device *gdev;
188 int base = ARCH_NR_GPIOS - ngpio;
190 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
191 /* found a free space? */
192 if (gdev->base + gdev->ngpio <= base)
195 /* nope, check the space right before the chip */
196 base = gdev->base - ngpio;
199 if (gpio_is_valid(base)) {
200 pr_debug("%s: found new base at %d\n", __func__, base);
203 pr_err("%s: cannot find free range\n", __func__);
209 * gpiod_get_direction - return the current direction of a GPIO
210 * @desc: GPIO to get the direction of
212 * Returns 0 for output, 1 for input, or an error code in case of error.
214 * This function may sleep if gpiod_cansleep() is true.
216 int gpiod_get_direction(struct gpio_desc *desc)
218 struct gpio_chip *gc;
222 gc = gpiod_to_chip(desc);
223 offset = gpio_chip_hwgpio(desc);
226 * Open drain emulation using input mode may incorrectly report
227 * input here, fix that up.
229 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) &&
230 test_bit(FLAG_IS_OUT, &desc->flags))
233 if (!gc->get_direction)
236 ret = gc->get_direction(gc, offset);
240 /* GPIOF_DIR_IN or other positive, otherwise GPIOF_DIR_OUT */
244 assign_bit(FLAG_IS_OUT, &desc->flags, !ret);
248 EXPORT_SYMBOL_GPL(gpiod_get_direction);
251 * Add a new chip to the global chips list, keeping the list of chips sorted
252 * by range(means [base, base + ngpio - 1]) order.
254 * Return -EBUSY if the new chip overlaps with some other chip's integer
257 static int gpiodev_add_to_list(struct gpio_device *gdev)
259 struct gpio_device *prev, *next;
261 if (list_empty(&gpio_devices)) {
262 /* initial entry in list */
263 list_add_tail(&gdev->list, &gpio_devices);
267 next = list_entry(gpio_devices.next, struct gpio_device, list);
268 if (gdev->base + gdev->ngpio <= next->base) {
269 /* add before first entry */
270 list_add(&gdev->list, &gpio_devices);
274 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
275 if (prev->base + prev->ngpio <= gdev->base) {
276 /* add behind last entry */
277 list_add_tail(&gdev->list, &gpio_devices);
281 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
282 /* at the end of the list */
283 if (&next->list == &gpio_devices)
286 /* add between prev and next */
287 if (prev->base + prev->ngpio <= gdev->base
288 && gdev->base + gdev->ngpio <= next->base) {
289 list_add(&gdev->list, &prev->list);
294 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
299 * Convert a GPIO name to its descriptor
300 * Note that there is no guarantee that GPIO names are globally unique!
301 * Hence this function will return, if it exists, a reference to the first GPIO
302 * line found that matches the given name.
304 static struct gpio_desc *gpio_name_to_desc(const char * const name)
306 struct gpio_device *gdev;
312 spin_lock_irqsave(&gpio_lock, flags);
314 list_for_each_entry(gdev, &gpio_devices, list) {
317 for (i = 0; i != gdev->ngpio; ++i) {
318 struct gpio_desc *desc = &gdev->descs[i];
323 if (!strcmp(desc->name, name)) {
324 spin_unlock_irqrestore(&gpio_lock, flags);
330 spin_unlock_irqrestore(&gpio_lock, flags);
336 * Take the names from gc->names and assign them to their GPIO descriptors.
337 * Warn if a name is already used for a GPIO line on a different GPIO chip.
340 * 1. Non-unique names are still accepted,
341 * 2. Name collisions within the same GPIO chip are not reported.
343 static int gpiochip_set_desc_names(struct gpio_chip *gc)
345 struct gpio_device *gdev = gc->gpiodev;
348 /* First check all names if they are unique */
349 for (i = 0; i != gc->ngpio; ++i) {
350 struct gpio_desc *gpio;
352 gpio = gpio_name_to_desc(gc->names[i]);
355 "Detected name collision for GPIO name '%s'\n",
359 /* Then add all names to the GPIO descriptors */
360 for (i = 0; i != gc->ngpio; ++i)
361 gdev->descs[i].name = gc->names[i];
367 * devprop_gpiochip_set_names - Set GPIO line names using device properties
368 * @chip: GPIO chip whose lines should be named, if possible
370 * Looks for device property "gpio-line-names" and if it exists assigns
371 * GPIO line names for the chip. The memory allocated for the assigned
372 * names belong to the underlying firmware node and should not be released
375 static int devprop_gpiochip_set_names(struct gpio_chip *chip)
377 struct gpio_device *gdev = chip->gpiodev;
378 struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
383 count = fwnode_property_string_array_count(fwnode, "gpio-line-names");
388 * When offset is set in the driver side we assume the driver internally
389 * is using more than one gpiochip per the same device. We have to stop
390 * setting friendly names if the specified ones with 'gpio-line-names'
391 * are less than the offset in the device itself. This means all the
392 * lines are not present for every single pin within all the internal
395 if (count <= chip->offset) {
396 dev_warn(&gdev->dev, "gpio-line-names too short (length %d), cannot map names for the gpiochip at offset %u\n",
397 count, chip->offset);
401 names = kcalloc(count, sizeof(*names), GFP_KERNEL);
405 ret = fwnode_property_read_string_array(fwnode, "gpio-line-names",
408 dev_warn(&gdev->dev, "failed to read GPIO line names\n");
414 * When more that one gpiochip per device is used, 'count' can
415 * contain at most number gpiochips x chip->ngpio. We have to
416 * correctly distribute all defined lines taking into account
417 * chip->offset as starting point from where we will assign
418 * the names to pins from the 'names' array. Since property
419 * 'gpio-line-names' cannot contains gaps, we have to be sure
420 * we only assign those pins that really exists since chip->ngpio
421 * can be different of the chip->offset.
423 count = (count > chip->offset) ? count - chip->offset : count;
424 if (count > chip->ngpio)
427 for (i = 0; i < count; i++)
428 gdev->descs[i].name = names[chip->offset + i];
435 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)
439 p = bitmap_alloc(gc->ngpio, GFP_KERNEL);
443 /* Assume by default all GPIOs are valid */
444 bitmap_fill(p, gc->ngpio);
449 static int gpiochip_alloc_valid_mask(struct gpio_chip *gc)
451 if (!(of_gpio_need_valid_mask(gc) || gc->init_valid_mask))
454 gc->valid_mask = gpiochip_allocate_mask(gc);
461 static int gpiochip_init_valid_mask(struct gpio_chip *gc)
463 if (gc->init_valid_mask)
464 return gc->init_valid_mask(gc,
471 static void gpiochip_free_valid_mask(struct gpio_chip *gc)
473 bitmap_free(gc->valid_mask);
474 gc->valid_mask = NULL;
477 static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
479 if (gc->add_pin_ranges)
480 return gc->add_pin_ranges(gc);
485 bool gpiochip_line_is_valid(const struct gpio_chip *gc,
488 /* No mask means all valid */
489 if (likely(!gc->valid_mask))
491 return test_bit(offset, gc->valid_mask);
493 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
495 static void gpiodevice_release(struct device *dev)
497 struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
500 spin_lock_irqsave(&gpio_lock, flags);
501 list_del(&gdev->list);
502 spin_unlock_irqrestore(&gpio_lock, flags);
504 ida_free(&gpio_ida, gdev->id);
505 kfree_const(gdev->label);
510 #ifdef CONFIG_GPIO_CDEV
511 #define gcdev_register(gdev, devt) gpiolib_cdev_register((gdev), (devt))
512 #define gcdev_unregister(gdev) gpiolib_cdev_unregister((gdev))
515 * gpiolib_cdev_register() indirectly calls device_add(), which is still
516 * required even when cdev is not selected.
518 #define gcdev_register(gdev, devt) device_add(&(gdev)->dev)
519 #define gcdev_unregister(gdev) device_del(&(gdev)->dev)
522 static int gpiochip_setup_dev(struct gpio_device *gdev)
526 ret = gcdev_register(gdev, gpio_devt);
530 ret = gpiochip_sysfs_register(gdev);
532 goto err_remove_device;
534 /* From this point, the .release() function cleans up gpio_device */
535 gdev->dev.release = gpiodevice_release;
536 dev_dbg(&gdev->dev, "registered GPIOs %d to %d on %s\n", gdev->base,
537 gdev->base + gdev->ngpio - 1, gdev->chip->label ? : "generic");
542 gcdev_unregister(gdev);
546 static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
548 struct gpio_desc *desc;
551 desc = gpiochip_get_desc(gc, hog->chip_hwnum);
553 chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,
558 if (test_bit(FLAG_IS_HOGGED, &desc->flags))
561 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
563 gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",
564 __func__, gc->label, hog->chip_hwnum, rv);
567 static void machine_gpiochip_add(struct gpio_chip *gc)
569 struct gpiod_hog *hog;
571 mutex_lock(&gpio_machine_hogs_mutex);
573 list_for_each_entry(hog, &gpio_machine_hogs, list) {
574 if (!strcmp(gc->label, hog->chip_label))
575 gpiochip_machine_hog(gc, hog);
578 mutex_unlock(&gpio_machine_hogs_mutex);
581 static void gpiochip_setup_devs(void)
583 struct gpio_device *gdev;
586 list_for_each_entry(gdev, &gpio_devices, list) {
587 ret = gpiochip_setup_dev(gdev);
590 "Failed to initialize gpio device (%d)\n", ret);
594 int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
595 struct lock_class_key *lock_key,
596 struct lock_class_key *request_key)
598 struct fwnode_handle *fwnode = gc->parent ? dev_fwnode(gc->parent) : NULL;
603 struct gpio_device *gdev;
606 * First: allocate and populate the internal stat container, and
607 * set up the struct device.
609 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
612 gdev->dev.bus = &gpio_bus_type;
613 gdev->dev.parent = gc->parent;
617 of_gpio_dev_init(gc, gdev);
618 acpi_gpio_dev_init(gc, gdev);
621 * Assign fwnode depending on the result of the previous calls,
622 * if none of them succeed, assign it to the parent's one.
624 gdev->dev.fwnode = dev_fwnode(&gdev->dev) ?: fwnode;
626 gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
632 ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
636 device_initialize(&gdev->dev);
637 if (gc->parent && gc->parent->driver)
638 gdev->owner = gc->parent->driver->owner;
640 /* TODO: remove chip->owner */
641 gdev->owner = gc->owner;
643 gdev->owner = THIS_MODULE;
645 gdev->descs = kcalloc(gc->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
648 goto err_free_dev_name;
651 if (gc->ngpio == 0) {
652 chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
657 if (gc->ngpio > FASTPATH_NGPIO)
658 chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n",
659 gc->ngpio, FASTPATH_NGPIO);
661 gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
667 gdev->ngpio = gc->ngpio;
670 spin_lock_irqsave(&gpio_lock, flags);
673 * TODO: this allocates a Linux GPIO number base in the global
674 * GPIO numberspace for this chip. In the long run we want to
675 * get *rid* of this numberspace and use only descriptors, but
676 * it may be a pipe dream. It will not happen before we get rid
677 * of the sysfs interface anyways.
680 base = gpiochip_find_base(gc->ngpio);
683 spin_unlock_irqrestore(&gpio_lock, flags);
687 * TODO: it should not be necessary to reflect the assigned
688 * base outside of the GPIO subsystem. Go over drivers and
689 * see if anyone makes use of this, else drop this and assign
696 ret = gpiodev_add_to_list(gdev);
698 spin_unlock_irqrestore(&gpio_lock, flags);
702 for (i = 0; i < gc->ngpio; i++)
703 gdev->descs[i].gdev = gdev;
705 spin_unlock_irqrestore(&gpio_lock, flags);
707 BLOCKING_INIT_NOTIFIER_HEAD(&gdev->notifier);
709 #ifdef CONFIG_PINCTRL
710 INIT_LIST_HEAD(&gdev->pin_ranges);
714 ret = gpiochip_set_desc_names(gc);
716 ret = devprop_gpiochip_set_names(gc);
718 goto err_remove_from_list;
720 ret = gpiochip_alloc_valid_mask(gc);
722 goto err_remove_from_list;
724 ret = of_gpiochip_add(gc);
726 goto err_free_gpiochip_mask;
728 ret = gpiochip_init_valid_mask(gc);
730 goto err_remove_of_chip;
732 for (i = 0; i < gc->ngpio; i++) {
733 struct gpio_desc *desc = &gdev->descs[i];
735 if (gc->get_direction && gpiochip_line_is_valid(gc, i)) {
736 assign_bit(FLAG_IS_OUT,
737 &desc->flags, !gc->get_direction(gc, i));
739 assign_bit(FLAG_IS_OUT,
740 &desc->flags, !gc->direction_input);
744 ret = gpiochip_add_pin_ranges(gc);
746 goto err_remove_of_chip;
748 acpi_gpiochip_add(gc);
750 machine_gpiochip_add(gc);
752 ret = gpiochip_irqchip_init_valid_mask(gc);
754 goto err_remove_acpi_chip;
756 ret = gpiochip_irqchip_init_hw(gc);
758 goto err_remove_acpi_chip;
760 ret = gpiochip_add_irqchip(gc, lock_key, request_key);
762 goto err_remove_irqchip_mask;
765 * By first adding the chardev, and then adding the device,
766 * we get a device node entry in sysfs under
767 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
768 * coldplug of device nodes and other udev business.
769 * We can do this only if gpiolib has been initialized.
770 * Otherwise, defer until later.
772 if (gpiolib_initialized) {
773 ret = gpiochip_setup_dev(gdev);
775 goto err_remove_irqchip;
780 gpiochip_irqchip_remove(gc);
781 err_remove_irqchip_mask:
782 gpiochip_irqchip_free_valid_mask(gc);
783 err_remove_acpi_chip:
784 acpi_gpiochip_remove(gc);
786 gpiochip_free_hogs(gc);
787 of_gpiochip_remove(gc);
788 err_free_gpiochip_mask:
789 gpiochip_remove_pin_ranges(gc);
790 gpiochip_free_valid_mask(gc);
791 err_remove_from_list:
792 spin_lock_irqsave(&gpio_lock, flags);
793 list_del(&gdev->list);
794 spin_unlock_irqrestore(&gpio_lock, flags);
796 kfree_const(gdev->label);
800 kfree(dev_name(&gdev->dev));
802 ida_free(&gpio_ida, gdev->id);
804 /* failures here can mean systems won't boot... */
805 if (ret != -EPROBE_DEFER) {
806 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
807 gdev->base, gdev->base + gdev->ngpio - 1,
808 gc->label ? : "generic", ret);
813 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
816 * gpiochip_get_data() - get per-subdriver data for the chip
820 * The per-subdriver data for the chip.
822 void *gpiochip_get_data(struct gpio_chip *gc)
824 return gc->gpiodev->data;
826 EXPORT_SYMBOL_GPL(gpiochip_get_data);
829 * gpiochip_remove() - unregister a gpio_chip
830 * @gc: the chip to unregister
832 * A gpio_chip with any GPIOs still requested may not be removed.
834 void gpiochip_remove(struct gpio_chip *gc)
836 struct gpio_device *gdev = gc->gpiodev;
840 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
841 gpiochip_sysfs_unregister(gdev);
842 gpiochip_free_hogs(gc);
843 /* Numb the device, cancelling all outstanding operations */
845 gpiochip_irqchip_remove(gc);
846 acpi_gpiochip_remove(gc);
847 of_gpiochip_remove(gc);
848 gpiochip_remove_pin_ranges(gc);
849 gpiochip_free_valid_mask(gc);
851 * We accept no more calls into the driver from this point, so
852 * NULL the driver data pointer
856 spin_lock_irqsave(&gpio_lock, flags);
857 for (i = 0; i < gdev->ngpio; i++) {
858 if (gpiochip_is_requested(gc, i))
861 spin_unlock_irqrestore(&gpio_lock, flags);
863 if (i != gdev->ngpio)
865 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
868 * The gpiochip side puts its use of the device to rest here:
869 * if there are no userspace clients, the chardev and device will
870 * be removed, else it will be dangling until the last user is
873 gcdev_unregister(gdev);
874 put_device(&gdev->dev);
876 EXPORT_SYMBOL_GPL(gpiochip_remove);
879 * gpiochip_find() - iterator for locating a specific gpio_chip
880 * @data: data to pass to match function
881 * @match: Callback function to check gpio_chip
883 * Similar to bus_find_device. It returns a reference to a gpio_chip as
884 * determined by a user supplied @match callback. The callback should return
885 * 0 if the device doesn't match and non-zero if it does. If the callback is
886 * non-zero, this function will return to the caller and not iterate over any
889 struct gpio_chip *gpiochip_find(void *data,
890 int (*match)(struct gpio_chip *gc,
893 struct gpio_device *gdev;
894 struct gpio_chip *gc = NULL;
897 spin_lock_irqsave(&gpio_lock, flags);
898 list_for_each_entry(gdev, &gpio_devices, list)
899 if (gdev->chip && match(gdev->chip, data)) {
904 spin_unlock_irqrestore(&gpio_lock, flags);
908 EXPORT_SYMBOL_GPL(gpiochip_find);
910 static int gpiochip_match_name(struct gpio_chip *gc, void *data)
912 const char *name = data;
914 return !strcmp(gc->label, name);
917 static struct gpio_chip *find_chip_by_name(const char *name)
919 return gpiochip_find((void *)name, gpiochip_match_name);
922 #ifdef CONFIG_GPIOLIB_IRQCHIP
925 * The following is irqchip helper code for gpiochips.
928 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
930 struct gpio_irq_chip *girq = &gc->irq;
935 return girq->init_hw(gc);
938 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
940 struct gpio_irq_chip *girq = &gc->irq;
942 if (!girq->init_valid_mask)
945 girq->valid_mask = gpiochip_allocate_mask(gc);
946 if (!girq->valid_mask)
949 girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
954 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
956 bitmap_free(gc->irq.valid_mask);
957 gc->irq.valid_mask = NULL;
960 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
963 if (!gpiochip_line_is_valid(gc, offset))
965 /* No mask means all valid */
966 if (likely(!gc->irq.valid_mask))
968 return test_bit(offset, gc->irq.valid_mask);
970 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
972 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
975 * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
977 * @gc: the gpiochip to set the irqchip hierarchical handler to
978 * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
979 * will then percolate up to the parent
981 static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
982 struct irq_chip *irqchip)
984 /* DT will deal with mapping each IRQ as we go along */
985 if (is_of_node(gc->irq.fwnode))
989 * This is for legacy and boardfile "irqchip" fwnodes: allocate
990 * irqs upfront instead of dynamically since we don't have the
991 * dynamic type of allocation that hardware description languages
992 * provide. Once all GPIO drivers using board files are gone from
993 * the kernel we can delete this code, but for a transitional period
994 * it is necessary to keep this around.
996 if (is_fwnode_irqchip(gc->irq.fwnode)) {
1000 for (i = 0; i < gc->ngpio; i++) {
1001 struct irq_fwspec fwspec;
1002 unsigned int parent_hwirq;
1003 unsigned int parent_type;
1004 struct gpio_irq_chip *girq = &gc->irq;
1007 * We call the child to parent translation function
1008 * only to check if the child IRQ is valid or not.
1009 * Just pick the rising edge type here as that is what
1010 * we likely need to support.
1012 ret = girq->child_to_parent_hwirq(gc, i,
1013 IRQ_TYPE_EDGE_RISING,
1017 chip_err(gc, "skip set-up on hwirq %d\n",
1022 fwspec.fwnode = gc->irq.fwnode;
1023 /* This is the hwirq for the GPIO line side of things */
1024 fwspec.param[0] = girq->child_offset_to_irq(gc, i);
1025 /* Just pick something */
1026 fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
1027 fwspec.param_count = 2;
1028 ret = __irq_domain_alloc_irqs(gc->irq.domain,
1029 /* just pick something */
1038 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
1045 chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
1050 static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
1051 struct irq_fwspec *fwspec,
1052 unsigned long *hwirq,
1055 /* We support standard DT translation */
1056 if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
1057 return irq_domain_translate_twocell(d, fwspec, hwirq, type);
1060 /* This is for board files and others not using DT */
1061 if (is_fwnode_irqchip(fwspec->fwnode)) {
1064 ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
1067 WARN_ON(*type == IRQ_TYPE_NONE);
1073 static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
1075 unsigned int nr_irqs,
1078 struct gpio_chip *gc = d->host_data;
1079 irq_hw_number_t hwirq;
1080 unsigned int type = IRQ_TYPE_NONE;
1081 struct irq_fwspec *fwspec = data;
1083 unsigned int parent_hwirq;
1084 unsigned int parent_type;
1085 struct gpio_irq_chip *girq = &gc->irq;
1089 * The nr_irqs parameter is always one except for PCI multi-MSI
1090 * so this should not happen.
1092 WARN_ON(nr_irqs != 1);
1094 ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
1098 chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
1100 ret = girq->child_to_parent_hwirq(gc, hwirq, type,
1101 &parent_hwirq, &parent_type);
1103 chip_err(gc, "can't look up hwirq %lu\n", hwirq);
1106 chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
1109 * We set handle_bad_irq because the .set_type() should
1110 * always be invoked and set the right type of handler.
1112 irq_domain_set_info(d,
1121 /* This parent only handles asserted level IRQs */
1122 parent_arg = girq->populate_parent_alloc_arg(gc, parent_hwirq, parent_type);
1126 chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
1128 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1129 ret = irq_domain_alloc_irqs_parent(d, irq, 1, parent_arg);
1131 * If the parent irqdomain is msi, the interrupts have already
1132 * been allocated, so the EEXIST is good.
1134 if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
1138 "failed to allocate parent hwirq %d for hwirq %lu\n",
1139 parent_hwirq, hwirq);
1145 static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
1146 unsigned int offset)
1151 static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
1153 ops->activate = gpiochip_irq_domain_activate;
1154 ops->deactivate = gpiochip_irq_domain_deactivate;
1155 ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
1156 ops->free = irq_domain_free_irqs_common;
1159 * We only allow overriding the translate() function for
1160 * hierarchical chips, and this should only be done if the user
1161 * really need something other than 1:1 translation.
1163 if (!ops->translate)
1164 ops->translate = gpiochip_hierarchy_irq_domain_translate;
1167 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1169 if (!gc->irq.child_to_parent_hwirq ||
1171 chip_err(gc, "missing irqdomain vital data\n");
1175 if (!gc->irq.child_offset_to_irq)
1176 gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
1178 if (!gc->irq.populate_parent_alloc_arg)
1179 gc->irq.populate_parent_alloc_arg =
1180 gpiochip_populate_parent_fwspec_twocell;
1182 gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
1184 gc->irq.domain = irq_domain_create_hierarchy(
1185 gc->irq.parent_domain,
1189 &gc->irq.child_irq_domain_ops,
1192 if (!gc->irq.domain)
1195 gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
1200 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1202 return !!gc->irq.parent_domain;
1205 void *gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
1206 unsigned int parent_hwirq,
1207 unsigned int parent_type)
1209 struct irq_fwspec *fwspec;
1211 fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
1215 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1216 fwspec->param_count = 2;
1217 fwspec->param[0] = parent_hwirq;
1218 fwspec->param[1] = parent_type;
1222 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
1224 void *gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
1225 unsigned int parent_hwirq,
1226 unsigned int parent_type)
1228 struct irq_fwspec *fwspec;
1230 fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
1234 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1235 fwspec->param_count = 4;
1236 fwspec->param[0] = 0;
1237 fwspec->param[1] = parent_hwirq;
1238 fwspec->param[2] = 0;
1239 fwspec->param[3] = parent_type;
1243 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
1247 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1252 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1257 #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
1260 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1261 * @d: the irqdomain used by this irqchip
1262 * @irq: the global irq number used by this GPIO irqchip irq
1263 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1265 * This function will set up the mapping for a certain IRQ line on a
1266 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1267 * stored inside the gpiochip.
1269 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1270 irq_hw_number_t hwirq)
1272 struct gpio_chip *gc = d->host_data;
1275 if (!gpiochip_irqchip_irq_valid(gc, hwirq))
1278 irq_set_chip_data(irq, gc);
1280 * This lock class tells lockdep that GPIO irqs are in a different
1281 * category than their parents, so it won't report false recursion.
1283 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1284 irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
1285 /* Chips that use nested thread handlers have them marked */
1286 if (gc->irq.threaded)
1287 irq_set_nested_thread(irq, 1);
1288 irq_set_noprobe(irq);
1290 if (gc->irq.num_parents == 1)
1291 ret = irq_set_parent(irq, gc->irq.parents[0]);
1292 else if (gc->irq.map)
1293 ret = irq_set_parent(irq, gc->irq.map[hwirq]);
1299 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1300 * is passed as default type.
1302 if (gc->irq.default_type != IRQ_TYPE_NONE)
1303 irq_set_irq_type(irq, gc->irq.default_type);
1307 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1309 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1311 struct gpio_chip *gc = d->host_data;
1313 if (gc->irq.threaded)
1314 irq_set_nested_thread(irq, 0);
1315 irq_set_chip_and_handler(irq, NULL, NULL);
1316 irq_set_chip_data(irq, NULL);
1318 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1320 static const struct irq_domain_ops gpiochip_domain_ops = {
1321 .map = gpiochip_irq_map,
1322 .unmap = gpiochip_irq_unmap,
1323 /* Virtually all GPIO irqchips are twocell:ed */
1324 .xlate = irq_domain_xlate_twocell,
1328 * TODO: move these activate/deactivate in under the hierarchicial
1329 * irqchip implementation as static once SPMI and SSBI (all external
1330 * users) are phased over.
1333 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1334 * @domain: The IRQ domain used by this IRQ chip
1335 * @data: Outermost irq_data associated with the IRQ
1336 * @reserve: If set, only reserve an interrupt vector instead of assigning one
1338 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1339 * used as the activate function for the &struct irq_domain_ops. The host_data
1340 * for the IRQ domain must be the &struct gpio_chip.
1342 int gpiochip_irq_domain_activate(struct irq_domain *domain,
1343 struct irq_data *data, bool reserve)
1345 struct gpio_chip *gc = domain->host_data;
1347 return gpiochip_lock_as_irq(gc, data->hwirq);
1349 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
1352 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1353 * @domain: The IRQ domain used by this IRQ chip
1354 * @data: Outermost irq_data associated with the IRQ
1356 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1357 * be used as the deactivate function for the &struct irq_domain_ops. The
1358 * host_data for the IRQ domain must be the &struct gpio_chip.
1360 void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1361 struct irq_data *data)
1363 struct gpio_chip *gc = domain->host_data;
1365 return gpiochip_unlock_as_irq(gc, data->hwirq);
1367 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
1369 static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)
1371 struct irq_domain *domain = gc->irq.domain;
1373 #ifdef CONFIG_GPIOLIB_IRQCHIP
1375 * Avoid race condition with other code, which tries to lookup
1376 * an IRQ before the irqchip has been properly registered,
1377 * i.e. while gpiochip is still being brought up.
1379 if (!gc->irq.initialized)
1380 return -EPROBE_DEFER;
1383 if (!gpiochip_irqchip_irq_valid(gc, offset))
1386 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1387 if (irq_domain_is_hierarchy(domain)) {
1388 struct irq_fwspec spec;
1390 spec.fwnode = domain->fwnode;
1391 spec.param_count = 2;
1392 spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
1393 spec.param[1] = IRQ_TYPE_NONE;
1395 return irq_create_fwspec_mapping(&spec);
1399 return irq_create_mapping(domain, offset);
1402 static int gpiochip_irq_reqres(struct irq_data *d)
1404 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1406 return gpiochip_reqres_irq(gc, d->hwirq);
1409 static void gpiochip_irq_relres(struct irq_data *d)
1411 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1413 gpiochip_relres_irq(gc, d->hwirq);
1416 static void gpiochip_irq_mask(struct irq_data *d)
1418 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1420 if (gc->irq.irq_mask)
1421 gc->irq.irq_mask(d);
1422 gpiochip_disable_irq(gc, d->hwirq);
1425 static void gpiochip_irq_unmask(struct irq_data *d)
1427 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1429 gpiochip_enable_irq(gc, d->hwirq);
1430 if (gc->irq.irq_unmask)
1431 gc->irq.irq_unmask(d);
1434 static void gpiochip_irq_enable(struct irq_data *d)
1436 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1438 gpiochip_enable_irq(gc, d->hwirq);
1439 gc->irq.irq_enable(d);
1442 static void gpiochip_irq_disable(struct irq_data *d)
1444 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1446 gc->irq.irq_disable(d);
1447 gpiochip_disable_irq(gc, d->hwirq);
1450 static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
1452 struct irq_chip *irqchip = gc->irq.chip;
1454 if (!irqchip->irq_request_resources &&
1455 !irqchip->irq_release_resources) {
1456 irqchip->irq_request_resources = gpiochip_irq_reqres;
1457 irqchip->irq_release_resources = gpiochip_irq_relres;
1459 if (WARN_ON(gc->irq.irq_enable))
1461 /* Check if the irqchip already has this hook... */
1462 if (irqchip->irq_enable == gpiochip_irq_enable ||
1463 irqchip->irq_mask == gpiochip_irq_mask) {
1465 * ...and if so, give a gentle warning that this is bad
1469 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1473 if (irqchip->irq_disable) {
1474 gc->irq.irq_disable = irqchip->irq_disable;
1475 irqchip->irq_disable = gpiochip_irq_disable;
1477 gc->irq.irq_mask = irqchip->irq_mask;
1478 irqchip->irq_mask = gpiochip_irq_mask;
1481 if (irqchip->irq_enable) {
1482 gc->irq.irq_enable = irqchip->irq_enable;
1483 irqchip->irq_enable = gpiochip_irq_enable;
1485 gc->irq.irq_unmask = irqchip->irq_unmask;
1486 irqchip->irq_unmask = gpiochip_irq_unmask;
1491 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1492 * @gc: the GPIO chip to add the IRQ chip to
1493 * @lock_key: lockdep class for IRQ lock
1494 * @request_key: lockdep class for IRQ request
1496 static int gpiochip_add_irqchip(struct gpio_chip *gc,
1497 struct lock_class_key *lock_key,
1498 struct lock_class_key *request_key)
1500 struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
1501 struct irq_chip *irqchip = gc->irq.chip;
1508 if (gc->irq.parent_handler && gc->can_sleep) {
1509 chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
1513 type = gc->irq.default_type;
1516 * Specifying a default trigger is a terrible idea if DT or ACPI is
1517 * used to configure the interrupts, as you may end up with
1518 * conflicting triggers. Tell the user, and reset to NONE.
1520 if (WARN(fwnode && type != IRQ_TYPE_NONE,
1521 "%pfw: Ignoring %u default trigger\n", fwnode, type))
1522 type = IRQ_TYPE_NONE;
1525 chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__);
1527 gc->to_irq = gpiochip_to_irq;
1528 gc->irq.default_type = type;
1529 gc->irq.lock_key = lock_key;
1530 gc->irq.request_key = request_key;
1532 /* If a parent irqdomain is provided, let's build a hierarchy */
1533 if (gpiochip_hierarchy_is_hierarchical(gc)) {
1534 int ret = gpiochip_hierarchy_add_domain(gc);
1538 /* Some drivers provide custom irqdomain ops */
1539 gc->irq.domain = irq_domain_create_simple(fwnode,
1542 gc->irq.domain_ops ?: &gpiochip_domain_ops,
1544 if (!gc->irq.domain)
1548 if (gc->irq.parent_handler) {
1549 void *data = gc->irq.parent_handler_data ?: gc;
1551 for (i = 0; i < gc->irq.num_parents; i++) {
1553 * The parent IRQ chip is already using the chip_data
1554 * for this IRQ chip, so our callbacks simply use the
1557 irq_set_chained_handler_and_data(gc->irq.parents[i],
1558 gc->irq.parent_handler,
1563 gpiochip_set_irq_hooks(gc);
1566 * Using barrier() here to prevent compiler from reordering
1567 * gc->irq.initialized before initialization of above
1568 * GPIO chip irq members.
1572 gc->irq.initialized = true;
1574 acpi_gpiochip_request_interrupts(gc);
1580 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1581 * @gc: the gpiochip to remove the irqchip from
1583 * This is called only from gpiochip_remove()
1585 static void gpiochip_irqchip_remove(struct gpio_chip *gc)
1587 struct irq_chip *irqchip = gc->irq.chip;
1588 unsigned int offset;
1590 acpi_gpiochip_free_interrupts(gc);
1592 if (irqchip && gc->irq.parent_handler) {
1593 struct gpio_irq_chip *irq = &gc->irq;
1596 for (i = 0; i < irq->num_parents; i++)
1597 irq_set_chained_handler_and_data(irq->parents[i],
1601 /* Remove all IRQ mappings and delete the domain */
1602 if (gc->irq.domain) {
1605 for (offset = 0; offset < gc->ngpio; offset++) {
1606 if (!gpiochip_irqchip_irq_valid(gc, offset))
1609 irq = irq_find_mapping(gc->irq.domain, offset);
1610 irq_dispose_mapping(irq);
1613 irq_domain_remove(gc->irq.domain);
1617 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
1618 irqchip->irq_request_resources = NULL;
1619 irqchip->irq_release_resources = NULL;
1621 if (irqchip->irq_enable == gpiochip_irq_enable) {
1622 irqchip->irq_enable = gc->irq.irq_enable;
1623 irqchip->irq_disable = gc->irq.irq_disable;
1626 gc->irq.irq_enable = NULL;
1627 gc->irq.irq_disable = NULL;
1628 gc->irq.chip = NULL;
1630 gpiochip_irqchip_free_valid_mask(gc);
1634 * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
1635 * @gc: the gpiochip to add the irqchip to
1636 * @domain: the irqdomain to add to the gpiochip
1638 * This function adds an IRQ domain to the gpiochip.
1640 int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
1641 struct irq_domain *domain)
1646 gc->to_irq = gpiochip_to_irq;
1647 gc->irq.domain = domain;
1651 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
1653 #else /* CONFIG_GPIOLIB_IRQCHIP */
1655 static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
1656 struct lock_class_key *lock_key,
1657 struct lock_class_key *request_key)
1661 static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
1663 static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1668 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1672 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
1675 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1678 * gpiochip_generic_request() - request the gpio function for a pin
1679 * @gc: the gpiochip owning the GPIO
1680 * @offset: the offset of the GPIO to request for GPIO function
1682 int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)
1684 #ifdef CONFIG_PINCTRL
1685 if (list_empty(&gc->gpiodev->pin_ranges))
1689 return pinctrl_gpio_request(gc->gpiodev->base + offset);
1691 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1694 * gpiochip_generic_free() - free the gpio function from a pin
1695 * @gc: the gpiochip to request the gpio function for
1696 * @offset: the offset of the GPIO to free from GPIO function
1698 void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset)
1700 #ifdef CONFIG_PINCTRL
1701 if (list_empty(&gc->gpiodev->pin_ranges))
1705 pinctrl_gpio_free(gc->gpiodev->base + offset);
1707 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1710 * gpiochip_generic_config() - apply configuration for a pin
1711 * @gc: the gpiochip owning the GPIO
1712 * @offset: the offset of the GPIO to apply the configuration
1713 * @config: the configuration to be applied
1715 int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
1716 unsigned long config)
1718 return pinctrl_gpio_set_config(gc->gpiodev->base + offset, config);
1720 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
1722 #ifdef CONFIG_PINCTRL
1725 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1726 * @gc: the gpiochip to add the range for
1727 * @pctldev: the pin controller to map to
1728 * @gpio_offset: the start offset in the current gpio_chip number space
1729 * @pin_group: name of the pin group inside the pin controller
1731 * Calling this function directly from a DeviceTree-supported
1732 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
1733 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
1734 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
1736 int gpiochip_add_pingroup_range(struct gpio_chip *gc,
1737 struct pinctrl_dev *pctldev,
1738 unsigned int gpio_offset, const char *pin_group)
1740 struct gpio_pin_range *pin_range;
1741 struct gpio_device *gdev = gc->gpiodev;
1744 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1746 chip_err(gc, "failed to allocate pin ranges\n");
1750 /* Use local offset as range ID */
1751 pin_range->range.id = gpio_offset;
1752 pin_range->range.gc = gc;
1753 pin_range->range.name = gc->label;
1754 pin_range->range.base = gdev->base + gpio_offset;
1755 pin_range->pctldev = pctldev;
1757 ret = pinctrl_get_group_pins(pctldev, pin_group,
1758 &pin_range->range.pins,
1759 &pin_range->range.npins);
1765 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1767 chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1768 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1769 pinctrl_dev_get_devname(pctldev), pin_group);
1771 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1775 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1778 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1779 * @gc: the gpiochip to add the range for
1780 * @pinctl_name: the dev_name() of the pin controller to map to
1781 * @gpio_offset: the start offset in the current gpio_chip number space
1782 * @pin_offset: the start offset in the pin controller number space
1783 * @npins: the number of pins from the offset of each pin space (GPIO and
1784 * pin controller) to accumulate in this range
1787 * 0 on success, or a negative error-code on failure.
1789 * Calling this function directly from a DeviceTree-supported
1790 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
1791 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
1792 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
1794 int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
1795 unsigned int gpio_offset, unsigned int pin_offset,
1798 struct gpio_pin_range *pin_range;
1799 struct gpio_device *gdev = gc->gpiodev;
1802 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1804 chip_err(gc, "failed to allocate pin ranges\n");
1808 /* Use local offset as range ID */
1809 pin_range->range.id = gpio_offset;
1810 pin_range->range.gc = gc;
1811 pin_range->range.name = gc->label;
1812 pin_range->range.base = gdev->base + gpio_offset;
1813 pin_range->range.pin_base = pin_offset;
1814 pin_range->range.npins = npins;
1815 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1817 if (IS_ERR(pin_range->pctldev)) {
1818 ret = PTR_ERR(pin_range->pctldev);
1819 chip_err(gc, "could not create pin range\n");
1823 chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1824 gpio_offset, gpio_offset + npins - 1,
1826 pin_offset, pin_offset + npins - 1);
1828 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1832 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1835 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1836 * @gc: the chip to remove all the mappings for
1838 void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
1840 struct gpio_pin_range *pin_range, *tmp;
1841 struct gpio_device *gdev = gc->gpiodev;
1843 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1844 list_del(&pin_range->node);
1845 pinctrl_remove_gpio_range(pin_range->pctldev,
1850 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1852 #endif /* CONFIG_PINCTRL */
1854 /* These "optional" allocation calls help prevent drivers from stomping
1855 * on each other, and help provide better diagnostics in debugfs.
1856 * They're called even less than the "set direction" calls.
1858 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
1860 struct gpio_chip *gc = desc->gdev->chip;
1862 unsigned long flags;
1866 label = kstrdup_const(label, GFP_KERNEL);
1871 spin_lock_irqsave(&gpio_lock, flags);
1873 /* NOTE: gpio_request() can be called in early boot,
1874 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1877 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1878 desc_set_label(desc, label ? : "?");
1881 goto out_free_unlock;
1885 /* gc->request may sleep */
1886 spin_unlock_irqrestore(&gpio_lock, flags);
1887 offset = gpio_chip_hwgpio(desc);
1888 if (gpiochip_line_is_valid(gc, offset))
1889 ret = gc->request(gc, offset);
1892 spin_lock_irqsave(&gpio_lock, flags);
1895 desc_set_label(desc, NULL);
1896 clear_bit(FLAG_REQUESTED, &desc->flags);
1897 goto out_free_unlock;
1900 if (gc->get_direction) {
1901 /* gc->get_direction may sleep */
1902 spin_unlock_irqrestore(&gpio_lock, flags);
1903 gpiod_get_direction(desc);
1904 spin_lock_irqsave(&gpio_lock, flags);
1906 spin_unlock_irqrestore(&gpio_lock, flags);
1910 spin_unlock_irqrestore(&gpio_lock, flags);
1916 * This descriptor validation needs to be inserted verbatim into each
1917 * function taking a descriptor, so we need to use a preprocessor
1918 * macro to avoid endless duplication. If the desc is NULL it is an
1919 * optional GPIO and calls should just bail out.
1921 static int validate_desc(const struct gpio_desc *desc, const char *func)
1926 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
1927 return PTR_ERR(desc);
1930 pr_warn("%s: invalid GPIO (no device)\n", func);
1933 if (!desc->gdev->chip) {
1934 dev_warn(&desc->gdev->dev,
1935 "%s: backing chip is gone\n", func);
1941 #define VALIDATE_DESC(desc) do { \
1942 int __valid = validate_desc(desc, __func__); \
1947 #define VALIDATE_DESC_VOID(desc) do { \
1948 int __valid = validate_desc(desc, __func__); \
1953 int gpiod_request(struct gpio_desc *desc, const char *label)
1955 int ret = -EPROBE_DEFER;
1956 struct gpio_device *gdev;
1958 VALIDATE_DESC(desc);
1961 if (try_module_get(gdev->owner)) {
1962 ret = gpiod_request_commit(desc, label);
1964 module_put(gdev->owner);
1966 get_device(&gdev->dev);
1970 gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
1975 static bool gpiod_free_commit(struct gpio_desc *desc)
1978 unsigned long flags;
1979 struct gpio_chip *gc;
1983 gpiod_unexport(desc);
1985 spin_lock_irqsave(&gpio_lock, flags);
1987 gc = desc->gdev->chip;
1988 if (gc && test_bit(FLAG_REQUESTED, &desc->flags)) {
1990 spin_unlock_irqrestore(&gpio_lock, flags);
1991 might_sleep_if(gc->can_sleep);
1992 gc->free(gc, gpio_chip_hwgpio(desc));
1993 spin_lock_irqsave(&gpio_lock, flags);
1995 kfree_const(desc->label);
1996 desc_set_label(desc, NULL);
1997 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
1998 clear_bit(FLAG_REQUESTED, &desc->flags);
1999 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2000 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2001 clear_bit(FLAG_PULL_UP, &desc->flags);
2002 clear_bit(FLAG_PULL_DOWN, &desc->flags);
2003 clear_bit(FLAG_BIAS_DISABLE, &desc->flags);
2004 clear_bit(FLAG_EDGE_RISING, &desc->flags);
2005 clear_bit(FLAG_EDGE_FALLING, &desc->flags);
2006 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2007 #ifdef CONFIG_OF_DYNAMIC
2010 #ifdef CONFIG_GPIO_CDEV
2011 WRITE_ONCE(desc->debounce_period_us, 0);
2016 spin_unlock_irqrestore(&gpio_lock, flags);
2017 blocking_notifier_call_chain(&desc->gdev->notifier,
2018 GPIOLINE_CHANGED_RELEASED, desc);
2023 void gpiod_free(struct gpio_desc *desc)
2025 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2026 module_put(desc->gdev->owner);
2027 put_device(&desc->gdev->dev);
2029 WARN_ON(extra_checks);
2034 * gpiochip_is_requested - return string iff signal was requested
2035 * @gc: controller managing the signal
2036 * @offset: of signal within controller's 0..(ngpio - 1) range
2038 * Returns NULL if the GPIO is not currently requested, else a string.
2039 * The string returned is the label passed to gpio_request(); if none has been
2040 * passed it is a meaningless, non-NULL constant.
2042 * This function is for use by GPIO controller drivers. The label can
2043 * help with diagnostics, and knowing that the signal is used as a GPIO
2044 * can help avoid accidentally multiplexing it to another controller.
2046 const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset)
2048 struct gpio_desc *desc;
2050 desc = gpiochip_get_desc(gc, offset);
2054 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2058 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2061 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2063 * @hwnum: hardware number of the GPIO for which to request the descriptor
2064 * @label: label for the GPIO
2065 * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2066 * specify things like line inversion semantics with the machine flags
2067 * such as GPIO_OUT_LOW
2068 * @dflags: descriptor request flags for this GPIO or 0 if default, this
2069 * can be used to specify consumer semantics such as open drain
2071 * Function allows GPIO chip drivers to request and use their own GPIO
2072 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2073 * function will not increase reference count of the GPIO chip module. This
2074 * allows the GPIO chip module to be unloaded as needed (we assume that the
2075 * GPIO chip driver handles freeing the GPIOs it has requested).
2078 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2081 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
2084 enum gpio_lookup_flags lflags,
2085 enum gpiod_flags dflags)
2087 struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
2091 chip_err(gc, "failed to get GPIO descriptor\n");
2095 ret = gpiod_request_commit(desc, label);
2097 return ERR_PTR(ret);
2099 ret = gpiod_configure_flags(desc, label, lflags, dflags);
2101 chip_err(gc, "setup of own GPIO %s failed\n", label);
2102 gpiod_free_commit(desc);
2103 return ERR_PTR(ret);
2108 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2111 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2112 * @desc: GPIO descriptor to free
2114 * Function frees the given GPIO requested previously with
2115 * gpiochip_request_own_desc().
2117 void gpiochip_free_own_desc(struct gpio_desc *desc)
2120 gpiod_free_commit(desc);
2122 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2125 * Drivers MUST set GPIO direction before making get/set calls. In
2126 * some cases this is done in early boot, before IRQs are enabled.
2128 * As a rule these aren't called more than once (except for drivers
2129 * using the open-drain emulation idiom) so these are natural places
2130 * to accumulate extra debugging checks. Note that we can't (yet)
2131 * rely on gpio_request() having been called beforehand.
2134 static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset,
2135 unsigned long config)
2137 if (!gc->set_config)
2140 return gc->set_config(gc, offset, config);
2143 static int gpio_set_config_with_argument(struct gpio_desc *desc,
2144 enum pin_config_param mode,
2147 struct gpio_chip *gc = desc->gdev->chip;
2148 unsigned long config;
2150 config = pinconf_to_config_packed(mode, argument);
2151 return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
2154 static int gpio_set_config_with_argument_optional(struct gpio_desc *desc,
2155 enum pin_config_param mode,
2158 struct device *dev = &desc->gdev->dev;
2159 int gpio = gpio_chip_hwgpio(desc);
2162 ret = gpio_set_config_with_argument(desc, mode, argument);
2163 if (ret != -ENOTSUPP)
2167 case PIN_CONFIG_PERSIST_STATE:
2168 dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio);
2177 static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
2179 return gpio_set_config_with_argument(desc, mode, 0);
2182 static int gpio_set_bias(struct gpio_desc *desc)
2184 enum pin_config_param bias;
2187 if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
2188 bias = PIN_CONFIG_BIAS_DISABLE;
2189 else if (test_bit(FLAG_PULL_UP, &desc->flags))
2190 bias = PIN_CONFIG_BIAS_PULL_UP;
2191 else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
2192 bias = PIN_CONFIG_BIAS_PULL_DOWN;
2197 case PIN_CONFIG_BIAS_PULL_DOWN:
2198 case PIN_CONFIG_BIAS_PULL_UP:
2207 return gpio_set_config_with_argument_optional(desc, bias, arg);
2211 * gpio_set_debounce_timeout() - Set debounce timeout
2212 * @desc: GPIO descriptor to set the debounce timeout
2213 * @debounce: Debounce timeout in microseconds
2215 * The function calls the certain GPIO driver to set debounce timeout
2218 * Returns 0 on success, or negative error code otherwise.
2220 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
2222 return gpio_set_config_with_argument_optional(desc,
2223 PIN_CONFIG_INPUT_DEBOUNCE,
2228 * gpiod_direction_input - set the GPIO direction to input
2229 * @desc: GPIO to set to input
2231 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2232 * be called safely on it.
2234 * Return 0 in case of success, else an error code.
2236 int gpiod_direction_input(struct gpio_desc *desc)
2238 struct gpio_chip *gc;
2241 VALIDATE_DESC(desc);
2242 gc = desc->gdev->chip;
2245 * It is legal to have no .get() and .direction_input() specified if
2246 * the chip is output-only, but you can't specify .direction_input()
2247 * and not support the .get() operation, that doesn't make sense.
2249 if (!gc->get && gc->direction_input) {
2251 "%s: missing get() but have direction_input()\n",
2257 * If we have a .direction_input() callback, things are simple,
2258 * just call it. Else we are some input-only chip so try to check the
2259 * direction (if .get_direction() is supported) else we silently
2260 * assume we are in input mode after this.
2262 if (gc->direction_input) {
2263 ret = gc->direction_input(gc, gpio_chip_hwgpio(desc));
2264 } else if (gc->get_direction &&
2265 (gc->get_direction(gc, gpio_chip_hwgpio(desc)) != 1)) {
2267 "%s: missing direction_input() operation and line is output\n",
2272 clear_bit(FLAG_IS_OUT, &desc->flags);
2273 ret = gpio_set_bias(desc);
2276 trace_gpio_direction(desc_to_gpio(desc), 1, ret);
2280 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2282 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2284 struct gpio_chip *gc = desc->gdev->chip;
2289 * It's OK not to specify .direction_output() if the gpiochip is
2290 * output-only, but if there is then not even a .set() operation it
2291 * is pretty tricky to drive the output line.
2293 if (!gc->set && !gc->direction_output) {
2295 "%s: missing set() and direction_output() operations\n",
2300 if (gc->direction_output) {
2301 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2303 /* Check that we are in output mode if we can */
2304 if (gc->get_direction &&
2305 gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
2307 "%s: missing direction_output() operation\n",
2312 * If we can't actively set the direction, we are some
2313 * output-only chip, so just drive the output as desired.
2315 gc->set(gc, gpio_chip_hwgpio(desc), val);
2319 set_bit(FLAG_IS_OUT, &desc->flags);
2320 trace_gpio_value(desc_to_gpio(desc), 0, val);
2321 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2326 * gpiod_direction_output_raw - set the GPIO direction to output
2327 * @desc: GPIO to set to output
2328 * @value: initial output value of the GPIO
2330 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2331 * be called safely on it. The initial value of the output must be specified
2332 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2334 * Return 0 in case of success, else an error code.
2336 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2338 VALIDATE_DESC(desc);
2339 return gpiod_direction_output_raw_commit(desc, value);
2341 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2344 * gpiod_direction_output - set the GPIO direction to output
2345 * @desc: GPIO to set to output
2346 * @value: initial output value of the GPIO
2348 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2349 * be called safely on it. The initial value of the output must be specified
2350 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2353 * Return 0 in case of success, else an error code.
2355 int gpiod_direction_output(struct gpio_desc *desc, int value)
2359 VALIDATE_DESC(desc);
2360 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2365 /* GPIOs used for enabled IRQs shall not be set as output */
2366 if (dont_test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
2367 dont_test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
2369 "%s: tried to set a GPIO tied to an IRQ as output\n",
2374 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2375 /* First see if we can enable open drain in hardware */
2376 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
2378 goto set_output_value;
2379 /* Emulate open drain by not actively driving the line high */
2381 ret = gpiod_direction_input(desc);
2382 goto set_output_flag;
2385 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2386 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
2388 goto set_output_value;
2389 /* Emulate open source by not actively driving the line low */
2391 ret = gpiod_direction_input(desc);
2392 goto set_output_flag;
2395 gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
2399 ret = gpio_set_bias(desc);
2402 return gpiod_direction_output_raw_commit(desc, value);
2406 * When emulating open-source or open-drain functionalities by not
2407 * actively driving the line (setting mode to input) we still need to
2408 * set the IS_OUT flag or otherwise we won't be able to set the line
2412 set_bit(FLAG_IS_OUT, &desc->flags);
2415 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2418 * gpiod_set_config - sets @config for a GPIO
2419 * @desc: descriptor of the GPIO for which to set the configuration
2420 * @config: Same packed config format as generic pinconf
2423 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2426 int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
2428 struct gpio_chip *gc;
2430 VALIDATE_DESC(desc);
2431 gc = desc->gdev->chip;
2433 return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
2435 EXPORT_SYMBOL_GPL(gpiod_set_config);
2438 * gpiod_set_debounce - sets @debounce time for a GPIO
2439 * @desc: descriptor of the GPIO for which to set debounce time
2440 * @debounce: debounce time in microseconds
2443 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2446 int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce)
2448 unsigned long config;
2450 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2451 return gpiod_set_config(desc, config);
2453 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2456 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2457 * @desc: descriptor of the GPIO for which to configure persistence
2458 * @transitory: True to lose state on suspend or reset, false for persistence
2461 * 0 on success, otherwise a negative error code.
2463 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2465 VALIDATE_DESC(desc);
2467 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2468 * persistence state.
2470 assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
2472 /* If the driver supports it, set the persistence state now */
2473 return gpio_set_config_with_argument_optional(desc,
2474 PIN_CONFIG_PERSIST_STATE,
2477 EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2480 * gpiod_is_active_low - test whether a GPIO is active-low or not
2481 * @desc: the gpio descriptor to test
2483 * Returns 1 if the GPIO is active-low, 0 otherwise.
2485 int gpiod_is_active_low(const struct gpio_desc *desc)
2487 VALIDATE_DESC(desc);
2488 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2490 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2493 * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
2494 * @desc: the gpio descriptor to change
2496 void gpiod_toggle_active_low(struct gpio_desc *desc)
2498 VALIDATE_DESC_VOID(desc);
2499 change_bit(FLAG_ACTIVE_LOW, &desc->flags);
2501 EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
2503 /* I/O calls are only valid after configuration completed; the relevant
2504 * "is this a valid GPIO" error checks should already have been done.
2506 * "Get" operations are often inlinable as reading a pin value register,
2507 * and masking the relevant bit in that register.
2509 * When "set" operations are inlinable, they involve writing that mask to
2510 * one register to set a low value, or a different register to set it high.
2511 * Otherwise locking is needed, so there may be little value to inlining.
2513 *------------------------------------------------------------------------
2515 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2516 * have requested the GPIO. That can include implicit requesting by
2517 * a direction setting call. Marking a gpio as requested locks its chip
2518 * in memory, guaranteeing that these table lookups need no more locking
2519 * and that gpiochip_remove() will fail.
2521 * REVISIT when debugging, consider adding some instrumentation to ensure
2522 * that the GPIO was actually requested.
2525 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2527 struct gpio_chip *gc;
2531 gc = desc->gdev->chip;
2532 offset = gpio_chip_hwgpio(desc);
2533 value = gc->get ? gc->get(gc, offset) : -EIO;
2534 value = value < 0 ? value : !!value;
2535 trace_gpio_value(desc_to_gpio(desc), 1, value);
2539 static int gpio_chip_get_multiple(struct gpio_chip *gc,
2540 unsigned long *mask, unsigned long *bits)
2542 if (gc->get_multiple) {
2543 return gc->get_multiple(gc, mask, bits);
2544 } else if (gc->get) {
2547 for_each_set_bit(i, mask, gc->ngpio) {
2548 value = gc->get(gc, i);
2551 __assign_bit(i, bits, value);
2558 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2559 unsigned int array_size,
2560 struct gpio_desc **desc_array,
2561 struct gpio_array *array_info,
2562 unsigned long *value_bitmap)
2567 * Validate array_info against desc_array and its size.
2568 * It should immediately follow desc_array if both
2569 * have been obtained from the same gpiod_get_array() call.
2571 if (array_info && array_info->desc == desc_array &&
2572 array_size <= array_info->size &&
2573 (void *)array_info == desc_array + array_info->size) {
2575 WARN_ON(array_info->chip->can_sleep);
2577 ret = gpio_chip_get_multiple(array_info->chip,
2578 array_info->get_mask,
2583 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2584 bitmap_xor(value_bitmap, value_bitmap,
2585 array_info->invert_mask, array_size);
2587 i = find_first_zero_bit(array_info->get_mask, array_size);
2588 if (i == array_size)
2594 while (i < array_size) {
2595 struct gpio_chip *gc = desc_array[i]->gdev->chip;
2596 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
2597 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
2598 unsigned long *mask, *bits;
2601 if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
2602 mask = fastpath_mask;
2603 bits = fastpath_bits;
2605 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
2607 mask = bitmap_alloc(gc->ngpio, flags);
2611 bits = bitmap_alloc(gc->ngpio, flags);
2618 bitmap_zero(mask, gc->ngpio);
2621 WARN_ON(gc->can_sleep);
2623 /* collect all inputs belonging to the same chip */
2626 const struct gpio_desc *desc = desc_array[i];
2627 int hwgpio = gpio_chip_hwgpio(desc);
2629 __set_bit(hwgpio, mask);
2633 i = find_next_zero_bit(array_info->get_mask,
2635 } while ((i < array_size) &&
2636 (desc_array[i]->gdev->chip == gc));
2638 ret = gpio_chip_get_multiple(gc, mask, bits);
2640 if (mask != fastpath_mask)
2642 if (bits != fastpath_bits)
2647 for (j = first; j < i; ) {
2648 const struct gpio_desc *desc = desc_array[j];
2649 int hwgpio = gpio_chip_hwgpio(desc);
2650 int value = test_bit(hwgpio, bits);
2652 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2654 __assign_bit(j, value_bitmap, value);
2655 trace_gpio_value(desc_to_gpio(desc), 1, value);
2659 j = find_next_zero_bit(array_info->get_mask, i,
2663 if (mask != fastpath_mask)
2665 if (bits != fastpath_bits)
2672 * gpiod_get_raw_value() - return a gpio's raw value
2673 * @desc: gpio whose value will be returned
2675 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2676 * its ACTIVE_LOW status, or negative errno on failure.
2678 * This function can be called from contexts where we cannot sleep, and will
2679 * complain if the GPIO chip functions potentially sleep.
2681 int gpiod_get_raw_value(const struct gpio_desc *desc)
2683 VALIDATE_DESC(desc);
2684 /* Should be using gpiod_get_raw_value_cansleep() */
2685 WARN_ON(desc->gdev->chip->can_sleep);
2686 return gpiod_get_raw_value_commit(desc);
2688 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2691 * gpiod_get_value() - return a gpio's value
2692 * @desc: gpio whose value will be returned
2694 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2695 * account, or negative errno on failure.
2697 * This function can be called from contexts where we cannot sleep, and will
2698 * complain if the GPIO chip functions potentially sleep.
2700 int gpiod_get_value(const struct gpio_desc *desc)
2704 VALIDATE_DESC(desc);
2705 /* Should be using gpiod_get_value_cansleep() */
2706 WARN_ON(desc->gdev->chip->can_sleep);
2708 value = gpiod_get_raw_value_commit(desc);
2712 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2717 EXPORT_SYMBOL_GPL(gpiod_get_value);
2720 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
2721 * @array_size: number of elements in the descriptor array / value bitmap
2722 * @desc_array: array of GPIO descriptors whose values will be read
2723 * @array_info: information on applicability of fast bitmap processing path
2724 * @value_bitmap: bitmap to store the read values
2726 * Read the raw values of the GPIOs, i.e. the values of the physical lines
2727 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
2728 * else an error code.
2730 * This function can be called from contexts where we cannot sleep,
2731 * and it will complain if the GPIO chip functions potentially sleep.
2733 int gpiod_get_raw_array_value(unsigned int array_size,
2734 struct gpio_desc **desc_array,
2735 struct gpio_array *array_info,
2736 unsigned long *value_bitmap)
2740 return gpiod_get_array_value_complex(true, false, array_size,
2741 desc_array, array_info,
2744 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
2747 * gpiod_get_array_value() - read values from an array of GPIOs
2748 * @array_size: number of elements in the descriptor array / value bitmap
2749 * @desc_array: array of GPIO descriptors whose values will be read
2750 * @array_info: information on applicability of fast bitmap processing path
2751 * @value_bitmap: bitmap to store the read values
2753 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2754 * into account. Return 0 in case of success, else an error code.
2756 * This function can be called from contexts where we cannot sleep,
2757 * and it will complain if the GPIO chip functions potentially sleep.
2759 int gpiod_get_array_value(unsigned int array_size,
2760 struct gpio_desc **desc_array,
2761 struct gpio_array *array_info,
2762 unsigned long *value_bitmap)
2766 return gpiod_get_array_value_complex(false, false, array_size,
2767 desc_array, array_info,
2770 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
2773 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
2774 * @desc: gpio descriptor whose state need to be set.
2775 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2777 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
2780 struct gpio_chip *gc = desc->gdev->chip;
2781 int offset = gpio_chip_hwgpio(desc);
2784 ret = gc->direction_input(gc, offset);
2786 ret = gc->direction_output(gc, offset, 0);
2788 set_bit(FLAG_IS_OUT, &desc->flags);
2790 trace_gpio_direction(desc_to_gpio(desc), value, ret);
2793 "%s: Error in set_value for open drain err %d\n",
2798 * _gpio_set_open_source_value() - Set the open source gpio's value.
2799 * @desc: gpio descriptor whose state need to be set.
2800 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2802 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
2805 struct gpio_chip *gc = desc->gdev->chip;
2806 int offset = gpio_chip_hwgpio(desc);
2809 ret = gc->direction_output(gc, offset, 1);
2811 set_bit(FLAG_IS_OUT, &desc->flags);
2813 ret = gc->direction_input(gc, offset);
2815 trace_gpio_direction(desc_to_gpio(desc), !value, ret);
2818 "%s: Error in set_value for open source err %d\n",
2822 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
2824 struct gpio_chip *gc;
2826 gc = desc->gdev->chip;
2827 trace_gpio_value(desc_to_gpio(desc), 0, value);
2828 gc->set(gc, gpio_chip_hwgpio(desc), value);
2832 * set multiple outputs on the same chip;
2833 * use the chip's set_multiple function if available;
2834 * otherwise set the outputs sequentially;
2835 * @chip: the GPIO chip we operate on
2836 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2837 * defines which outputs are to be changed
2838 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2839 * defines the values the outputs specified by mask are to be set to
2841 static void gpio_chip_set_multiple(struct gpio_chip *gc,
2842 unsigned long *mask, unsigned long *bits)
2844 if (gc->set_multiple) {
2845 gc->set_multiple(gc, mask, bits);
2849 /* set outputs if the corresponding mask bit is set */
2850 for_each_set_bit(i, mask, gc->ngpio)
2851 gc->set(gc, i, test_bit(i, bits));
2855 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
2856 unsigned int array_size,
2857 struct gpio_desc **desc_array,
2858 struct gpio_array *array_info,
2859 unsigned long *value_bitmap)
2864 * Validate array_info against desc_array and its size.
2865 * It should immediately follow desc_array if both
2866 * have been obtained from the same gpiod_get_array() call.
2868 if (array_info && array_info->desc == desc_array &&
2869 array_size <= array_info->size &&
2870 (void *)array_info == desc_array + array_info->size) {
2872 WARN_ON(array_info->chip->can_sleep);
2874 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2875 bitmap_xor(value_bitmap, value_bitmap,
2876 array_info->invert_mask, array_size);
2878 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
2881 i = find_first_zero_bit(array_info->set_mask, array_size);
2882 if (i == array_size)
2888 while (i < array_size) {
2889 struct gpio_chip *gc = desc_array[i]->gdev->chip;
2890 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
2891 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
2892 unsigned long *mask, *bits;
2895 if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
2896 mask = fastpath_mask;
2897 bits = fastpath_bits;
2899 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
2901 mask = bitmap_alloc(gc->ngpio, flags);
2905 bits = bitmap_alloc(gc->ngpio, flags);
2912 bitmap_zero(mask, gc->ngpio);
2915 WARN_ON(gc->can_sleep);
2918 struct gpio_desc *desc = desc_array[i];
2919 int hwgpio = gpio_chip_hwgpio(desc);
2920 int value = test_bit(i, value_bitmap);
2923 * Pins applicable for fast input but not for
2924 * fast output processing may have been already
2925 * inverted inside the fast path, skip them.
2927 if (!raw && !(array_info &&
2928 test_bit(i, array_info->invert_mask)) &&
2929 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2931 trace_gpio_value(desc_to_gpio(desc), 0, value);
2933 * collect all normal outputs belonging to the same chip
2934 * open drain and open source outputs are set individually
2936 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
2937 gpio_set_open_drain_value_commit(desc, value);
2938 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
2939 gpio_set_open_source_value_commit(desc, value);
2941 __set_bit(hwgpio, mask);
2942 __assign_bit(hwgpio, bits, value);
2948 i = find_next_zero_bit(array_info->set_mask,
2950 } while ((i < array_size) &&
2951 (desc_array[i]->gdev->chip == gc));
2952 /* push collected bits to outputs */
2954 gpio_chip_set_multiple(gc, mask, bits);
2956 if (mask != fastpath_mask)
2958 if (bits != fastpath_bits)
2965 * gpiod_set_raw_value() - assign a gpio's raw value
2966 * @desc: gpio whose value will be assigned
2967 * @value: value to assign
2969 * Set the raw value of the GPIO, i.e. the value of its physical line without
2970 * regard for its ACTIVE_LOW status.
2972 * This function can be called from contexts where we cannot sleep, and will
2973 * complain if the GPIO chip functions potentially sleep.
2975 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
2977 VALIDATE_DESC_VOID(desc);
2978 /* Should be using gpiod_set_raw_value_cansleep() */
2979 WARN_ON(desc->gdev->chip->can_sleep);
2980 gpiod_set_raw_value_commit(desc, value);
2982 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
2985 * gpiod_set_value_nocheck() - set a GPIO line value without checking
2986 * @desc: the descriptor to set the value on
2987 * @value: value to set
2989 * This sets the value of a GPIO line backing a descriptor, applying
2990 * different semantic quirks like active low and open drain/source
2993 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
2995 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2997 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
2998 gpio_set_open_drain_value_commit(desc, value);
2999 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3000 gpio_set_open_source_value_commit(desc, value);
3002 gpiod_set_raw_value_commit(desc, value);
3006 * gpiod_set_value() - assign a gpio's value
3007 * @desc: gpio whose value will be assigned
3008 * @value: value to assign
3010 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3011 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3013 * This function can be called from contexts where we cannot sleep, and will
3014 * complain if the GPIO chip functions potentially sleep.
3016 void gpiod_set_value(struct gpio_desc *desc, int value)
3018 VALIDATE_DESC_VOID(desc);
3019 /* Should be using gpiod_set_value_cansleep() */
3020 WARN_ON(desc->gdev->chip->can_sleep);
3021 gpiod_set_value_nocheck(desc, value);
3023 EXPORT_SYMBOL_GPL(gpiod_set_value);
3026 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3027 * @array_size: number of elements in the descriptor array / value bitmap
3028 * @desc_array: array of GPIO descriptors whose values will be assigned
3029 * @array_info: information on applicability of fast bitmap processing path
3030 * @value_bitmap: bitmap of values to assign
3032 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3033 * without regard for their ACTIVE_LOW status.
3035 * This function can be called from contexts where we cannot sleep, and will
3036 * complain if the GPIO chip functions potentially sleep.
3038 int gpiod_set_raw_array_value(unsigned int array_size,
3039 struct gpio_desc **desc_array,
3040 struct gpio_array *array_info,
3041 unsigned long *value_bitmap)
3045 return gpiod_set_array_value_complex(true, false, array_size,
3046 desc_array, array_info, value_bitmap);
3048 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3051 * gpiod_set_array_value() - assign values to an array of GPIOs
3052 * @array_size: number of elements in the descriptor array / value bitmap
3053 * @desc_array: array of GPIO descriptors whose values will be assigned
3054 * @array_info: information on applicability of fast bitmap processing path
3055 * @value_bitmap: bitmap of values to assign
3057 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3060 * This function can be called from contexts where we cannot sleep, and will
3061 * complain if the GPIO chip functions potentially sleep.
3063 int gpiod_set_array_value(unsigned int array_size,
3064 struct gpio_desc **desc_array,
3065 struct gpio_array *array_info,
3066 unsigned long *value_bitmap)
3070 return gpiod_set_array_value_complex(false, false, array_size,
3071 desc_array, array_info,
3074 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3077 * gpiod_cansleep() - report whether gpio value access may sleep
3078 * @desc: gpio to check
3081 int gpiod_cansleep(const struct gpio_desc *desc)
3083 VALIDATE_DESC(desc);
3084 return desc->gdev->chip->can_sleep;
3086 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3089 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3090 * @desc: gpio to set the consumer name on
3091 * @name: the new consumer name
3093 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3095 VALIDATE_DESC(desc);
3097 name = kstrdup_const(name, GFP_KERNEL);
3102 kfree_const(desc->label);
3103 desc_set_label(desc, name);
3107 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3110 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3111 * @desc: gpio whose IRQ will be returned (already requested)
3113 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3116 int gpiod_to_irq(const struct gpio_desc *desc)
3118 struct gpio_chip *gc;
3122 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3123 * requires this function to not return zero on an invalid descriptor
3124 * but rather a negative error number.
3126 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3129 gc = desc->gdev->chip;
3130 offset = gpio_chip_hwgpio(desc);
3132 int retirq = gc->to_irq(gc, offset);
3134 /* Zero means NO_IRQ */
3140 #ifdef CONFIG_GPIOLIB_IRQCHIP
3143 * Avoid race condition with other code, which tries to lookup
3144 * an IRQ before the irqchip has been properly registered,
3145 * i.e. while gpiochip is still being brought up.
3147 return -EPROBE_DEFER;
3152 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3155 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3156 * @gc: the chip the GPIO to lock belongs to
3157 * @offset: the offset of the GPIO to lock as IRQ
3159 * This is used directly by GPIO drivers that want to lock down
3160 * a certain GPIO line to be used for IRQs.
3162 int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
3164 struct gpio_desc *desc;
3166 desc = gpiochip_get_desc(gc, offset);
3168 return PTR_ERR(desc);
3171 * If it's fast: flush the direction setting if something changed
3174 if (!gc->can_sleep && gc->get_direction) {
3175 int dir = gpiod_get_direction(desc);
3178 chip_err(gc, "%s: cannot get GPIO direction\n",
3184 /* To be valid for IRQ the line needs to be input or open drain */
3185 if (dont_test_bit(FLAG_IS_OUT, &desc->flags) &&
3186 !dont_test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
3188 "%s: tried to flag a GPIO set as output for IRQ\n",
3193 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3194 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3197 * If the consumer has not set up a label (such as when the
3198 * IRQ is referenced from .to_irq()) we set up a label here
3199 * so it is clear this is used as an interrupt.
3202 desc_set_label(desc, "interrupt");
3206 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3209 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3210 * @gc: the chip the GPIO to lock belongs to
3211 * @offset: the offset of the GPIO to lock as IRQ
3213 * This is used directly by GPIO drivers that want to indicate
3214 * that a certain GPIO is no longer used exclusively for IRQ.
3216 void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
3218 struct gpio_desc *desc;
3220 desc = gpiochip_get_desc(gc, offset);
3224 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3225 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3227 /* If we only had this marking, erase it */
3228 if (desc->label && !strcmp(desc->label, "interrupt"))
3229 desc_set_label(desc, NULL);
3231 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3233 void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
3235 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3237 if (!IS_ERR(desc) &&
3238 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3239 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3241 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3243 void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
3245 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3247 if (!IS_ERR(desc) &&
3248 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3250 * We must not be output when using IRQ UNLESS we are
3253 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
3254 !test_bit(FLAG_OPEN_DRAIN, &desc->flags));
3255 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3258 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3260 bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
3262 if (offset >= gc->ngpio)
3265 return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
3267 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3269 int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
3273 if (!try_module_get(gc->gpiodev->owner))
3276 ret = gpiochip_lock_as_irq(gc, offset);
3278 chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
3279 module_put(gc->gpiodev->owner);
3284 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3286 void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
3288 gpiochip_unlock_as_irq(gc, offset);
3289 module_put(gc->gpiodev->owner);
3291 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3293 bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
3295 if (offset >= gc->ngpio)
3298 return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
3300 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3302 bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
3304 if (offset >= gc->ngpio)
3307 return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
3309 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3311 bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
3313 if (offset >= gc->ngpio)
3316 return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
3318 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3321 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3322 * @desc: gpio whose value will be returned
3324 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3325 * its ACTIVE_LOW status, or negative errno on failure.
3327 * This function is to be called from contexts that can sleep.
3329 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3331 might_sleep_if(extra_checks);
3332 VALIDATE_DESC(desc);
3333 return gpiod_get_raw_value_commit(desc);
3335 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3338 * gpiod_get_value_cansleep() - return a gpio's value
3339 * @desc: gpio whose value will be returned
3341 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3342 * account, or negative errno on failure.
3344 * This function is to be called from contexts that can sleep.
3346 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3350 might_sleep_if(extra_checks);
3351 VALIDATE_DESC(desc);
3352 value = gpiod_get_raw_value_commit(desc);
3356 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3361 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3364 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3365 * @array_size: number of elements in the descriptor array / value bitmap
3366 * @desc_array: array of GPIO descriptors whose values will be read
3367 * @array_info: information on applicability of fast bitmap processing path
3368 * @value_bitmap: bitmap to store the read values
3370 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3371 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3372 * else an error code.
3374 * This function is to be called from contexts that can sleep.
3376 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3377 struct gpio_desc **desc_array,
3378 struct gpio_array *array_info,
3379 unsigned long *value_bitmap)
3381 might_sleep_if(extra_checks);
3384 return gpiod_get_array_value_complex(true, true, array_size,
3385 desc_array, array_info,
3388 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3391 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3392 * @array_size: number of elements in the descriptor array / value bitmap
3393 * @desc_array: array of GPIO descriptors whose values will be read
3394 * @array_info: information on applicability of fast bitmap processing path
3395 * @value_bitmap: bitmap to store the read values
3397 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3398 * into account. Return 0 in case of success, else an error code.
3400 * This function is to be called from contexts that can sleep.
3402 int gpiod_get_array_value_cansleep(unsigned int array_size,
3403 struct gpio_desc **desc_array,
3404 struct gpio_array *array_info,
3405 unsigned long *value_bitmap)
3407 might_sleep_if(extra_checks);
3410 return gpiod_get_array_value_complex(false, true, array_size,
3411 desc_array, array_info,
3414 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3417 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3418 * @desc: gpio whose value will be assigned
3419 * @value: value to assign
3421 * Set the raw value of the GPIO, i.e. the value of its physical line without
3422 * regard for its ACTIVE_LOW status.
3424 * This function is to be called from contexts that can sleep.
3426 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3428 might_sleep_if(extra_checks);
3429 VALIDATE_DESC_VOID(desc);
3430 gpiod_set_raw_value_commit(desc, value);
3432 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3435 * gpiod_set_value_cansleep() - assign a gpio's value
3436 * @desc: gpio whose value will be assigned
3437 * @value: value to assign
3439 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3442 * This function is to be called from contexts that can sleep.
3444 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3446 might_sleep_if(extra_checks);
3447 VALIDATE_DESC_VOID(desc);
3448 gpiod_set_value_nocheck(desc, value);
3450 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3453 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3454 * @array_size: number of elements in the descriptor array / value bitmap
3455 * @desc_array: array of GPIO descriptors whose values will be assigned
3456 * @array_info: information on applicability of fast bitmap processing path
3457 * @value_bitmap: bitmap of values to assign
3459 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3460 * without regard for their ACTIVE_LOW status.
3462 * This function is to be called from contexts that can sleep.
3464 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3465 struct gpio_desc **desc_array,
3466 struct gpio_array *array_info,
3467 unsigned long *value_bitmap)
3469 might_sleep_if(extra_checks);
3472 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3473 array_info, value_bitmap);
3475 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3478 * gpiod_add_lookup_tables() - register GPIO device consumers
3479 * @tables: list of tables of consumers to register
3480 * @n: number of tables in the list
3482 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3486 mutex_lock(&gpio_lookup_lock);
3488 for (i = 0; i < n; i++)
3489 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3491 mutex_unlock(&gpio_lookup_lock);
3495 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3496 * @array_size: number of elements in the descriptor array / value bitmap
3497 * @desc_array: array of GPIO descriptors whose values will be assigned
3498 * @array_info: information on applicability of fast bitmap processing path
3499 * @value_bitmap: bitmap of values to assign
3501 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3504 * This function is to be called from contexts that can sleep.
3506 int gpiod_set_array_value_cansleep(unsigned int array_size,
3507 struct gpio_desc **desc_array,
3508 struct gpio_array *array_info,
3509 unsigned long *value_bitmap)
3511 might_sleep_if(extra_checks);
3514 return gpiod_set_array_value_complex(false, true, array_size,
3515 desc_array, array_info,
3518 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3521 * gpiod_add_lookup_table() - register GPIO device consumers
3522 * @table: table of consumers to register
3524 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3526 mutex_lock(&gpio_lookup_lock);
3528 list_add_tail(&table->list, &gpio_lookup_list);
3530 mutex_unlock(&gpio_lookup_lock);
3532 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3535 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3536 * @table: table of consumers to unregister
3538 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3540 /* Nothing to remove */
3544 mutex_lock(&gpio_lookup_lock);
3546 list_del(&table->list);
3548 mutex_unlock(&gpio_lookup_lock);
3550 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3553 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
3554 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
3556 void gpiod_add_hogs(struct gpiod_hog *hogs)
3558 struct gpio_chip *gc;
3559 struct gpiod_hog *hog;
3561 mutex_lock(&gpio_machine_hogs_mutex);
3563 for (hog = &hogs[0]; hog->chip_label; hog++) {
3564 list_add_tail(&hog->list, &gpio_machine_hogs);
3567 * The chip may have been registered earlier, so check if it
3568 * exists and, if so, try to hog the line now.
3570 gc = find_chip_by_name(hog->chip_label);
3572 gpiochip_machine_hog(gc, hog);
3575 mutex_unlock(&gpio_machine_hogs_mutex);
3577 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
3579 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3581 const char *dev_id = dev ? dev_name(dev) : NULL;
3582 struct gpiod_lookup_table *table;
3584 mutex_lock(&gpio_lookup_lock);
3586 list_for_each_entry(table, &gpio_lookup_list, list) {
3587 if (table->dev_id && dev_id) {
3589 * Valid strings on both ends, must be identical to have
3592 if (!strcmp(table->dev_id, dev_id))
3596 * One of the pointers is NULL, so both must be to have
3599 if (dev_id == table->dev_id)
3606 mutex_unlock(&gpio_lookup_lock);
3610 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3611 unsigned int idx, unsigned long *flags)
3613 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3614 struct gpiod_lookup_table *table;
3615 struct gpiod_lookup *p;
3617 table = gpiod_find_lookup_table(dev);
3621 for (p = &table->table[0]; p->key; p++) {
3622 struct gpio_chip *gc;
3624 /* idx must always match exactly */
3628 /* If the lookup entry has a con_id, require exact match */
3629 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3632 if (p->chip_hwnum == U16_MAX) {
3633 desc = gpio_name_to_desc(p->key);
3639 dev_warn(dev, "cannot find GPIO line %s, deferring\n",
3641 return ERR_PTR(-EPROBE_DEFER);
3644 gc = find_chip_by_name(p->key);
3648 * As the lookup table indicates a chip with
3649 * p->key should exist, assume it may
3650 * still appear later and let the interested
3651 * consumer be probed again or let the Deferred
3652 * Probe infrastructure handle the error.
3654 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
3656 return ERR_PTR(-EPROBE_DEFER);
3659 if (gc->ngpio <= p->chip_hwnum) {
3661 "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
3662 idx, p->chip_hwnum, gc->ngpio - 1,
3664 return ERR_PTR(-EINVAL);
3667 desc = gpiochip_get_desc(gc, p->chip_hwnum);
3676 static int platform_gpio_count(struct device *dev, const char *con_id)
3678 struct gpiod_lookup_table *table;
3679 struct gpiod_lookup *p;
3680 unsigned int count = 0;
3682 table = gpiod_find_lookup_table(dev);
3686 for (p = &table->table[0]; p->key; p++) {
3687 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3688 (!con_id && !p->con_id))
3698 * fwnode_gpiod_get_index - obtain a GPIO from firmware node
3699 * @fwnode: handle of the firmware node
3700 * @con_id: function within the GPIO consumer
3701 * @index: index of the GPIO to obtain for the consumer
3702 * @flags: GPIO initialization flags
3703 * @label: label to attach to the requested GPIO
3705 * This function can be used for drivers that get their configuration
3706 * from opaque firmware.
3708 * The function properly finds the corresponding GPIO using whatever is the
3709 * underlying firmware interface and then makes sure that the GPIO
3710 * descriptor is requested before it is returned to the caller.
3713 * On successful request the GPIO pin is configured in accordance with
3716 * In case of error an ERR_PTR() is returned.
3718 struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
3719 const char *con_id, int index,
3720 enum gpiod_flags flags,
3723 struct gpio_desc *desc;
3724 char prop_name[32]; /* 32 is max size of property name */
3727 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3729 snprintf(prop_name, sizeof(prop_name), "%s-%s",
3730 con_id, gpio_suffixes[i]);
3732 snprintf(prop_name, sizeof(prop_name), "%s",
3735 desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
3737 if (!gpiod_not_found(desc))
3743 EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
3746 * gpiod_count - return the number of GPIOs associated with a device / function
3747 * or -ENOENT if no GPIO has been assigned to the requested function
3748 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3749 * @con_id: function within the GPIO consumer
3751 int gpiod_count(struct device *dev, const char *con_id)
3753 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
3754 int count = -ENOENT;
3756 if (is_of_node(fwnode))
3757 count = of_gpio_get_count(dev, con_id);
3758 else if (is_acpi_node(fwnode))
3759 count = acpi_gpio_count(dev, con_id);
3762 count = platform_gpio_count(dev, con_id);
3766 EXPORT_SYMBOL_GPL(gpiod_count);
3769 * gpiod_get - obtain a GPIO for a given GPIO function
3770 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3771 * @con_id: function within the GPIO consumer
3772 * @flags: optional GPIO initialization flags
3774 * Return the GPIO descriptor corresponding to the function con_id of device
3775 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3776 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3778 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3779 enum gpiod_flags flags)
3781 return gpiod_get_index(dev, con_id, 0, flags);
3783 EXPORT_SYMBOL_GPL(gpiod_get);
3786 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3787 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3788 * @con_id: function within the GPIO consumer
3789 * @flags: optional GPIO initialization flags
3791 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3792 * the requested function it will return NULL. This is convenient for drivers
3793 * that need to handle optional GPIOs.
3795 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3797 enum gpiod_flags flags)
3799 return gpiod_get_index_optional(dev, con_id, 0, flags);
3801 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3805 * gpiod_configure_flags - helper function to configure a given GPIO
3806 * @desc: gpio whose value will be assigned
3807 * @con_id: function within the GPIO consumer
3808 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
3809 * of_find_gpio() or of_get_gpio_hog()
3810 * @dflags: gpiod_flags - optional GPIO initialization flags
3812 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3813 * requested function and/or index, or another IS_ERR() code if an error
3814 * occurred while trying to acquire the GPIO.
3816 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3817 unsigned long lflags, enum gpiod_flags dflags)
3821 if (lflags & GPIO_ACTIVE_LOW)
3822 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3824 if (lflags & GPIO_OPEN_DRAIN)
3825 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3826 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
3828 * This enforces open drain mode from the consumer side.
3829 * This is necessary for some busses like I2C, but the lookup
3830 * should *REALLY* have specified them as open drain in the
3831 * first place, so print a little warning here.
3833 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3835 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
3838 if (lflags & GPIO_OPEN_SOURCE)
3839 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3841 if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
3843 "both pull-up and pull-down enabled, invalid configuration\n");
3847 if (lflags & GPIO_PULL_UP)
3848 set_bit(FLAG_PULL_UP, &desc->flags);
3849 else if (lflags & GPIO_PULL_DOWN)
3850 set_bit(FLAG_PULL_DOWN, &desc->flags);
3852 ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
3856 /* No particular flag request, return here... */
3857 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3858 gpiod_dbg(desc, "no flags found for %s\n", con_id);
3863 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3864 ret = gpiod_direction_output(desc,
3865 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3867 ret = gpiod_direction_input(desc);
3873 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3874 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3875 * @con_id: function within the GPIO consumer
3876 * @idx: index of the GPIO to obtain in the consumer
3877 * @flags: optional GPIO initialization flags
3879 * This variant of gpiod_get() allows to access GPIOs other than the first
3880 * defined one for functions that define several GPIOs.
3882 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3883 * requested function and/or index, or another IS_ERR() code if an error
3884 * occurred while trying to acquire the GPIO.
3886 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3889 enum gpiod_flags flags)
3891 unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
3892 struct gpio_desc *desc = NULL;
3894 /* Maybe we have a device name, maybe not */
3895 const char *devname = dev ? dev_name(dev) : "?";
3896 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
3898 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3900 /* Using device tree? */
3901 if (is_of_node(fwnode)) {
3902 dev_dbg(dev, "using device tree for GPIO lookup\n");
3903 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3904 } else if (is_acpi_node(fwnode)) {
3905 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3906 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
3910 * Either we are not using DT or ACPI, or their lookup did not return
3911 * a result. In that case, use platform lookup as a fallback.
3913 if (!desc || gpiod_not_found(desc)) {
3914 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3915 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3919 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
3924 * If a connection label was passed use that, else attempt to use
3925 * the device name as label
3927 ret = gpiod_request(desc, con_id ? con_id : devname);
3929 if (ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
3931 * This happens when there are several consumers for
3932 * the same GPIO line: we just return here without
3933 * further initialization. It is a bit if a hack.
3934 * This is necessary to support fixed regulators.
3936 * FIXME: Make this more sane and safe.
3938 dev_info(dev, "nonexclusive access to GPIO for %s\n",
3939 con_id ? con_id : devname);
3942 return ERR_PTR(ret);
3946 ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3948 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3950 return ERR_PTR(ret);
3953 blocking_notifier_call_chain(&desc->gdev->notifier,
3954 GPIOLINE_CHANGED_REQUESTED, desc);
3958 EXPORT_SYMBOL_GPL(gpiod_get_index);
3961 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3962 * @fwnode: handle of the firmware node
3963 * @propname: name of the firmware property representing the GPIO
3964 * @index: index of the GPIO to obtain for the consumer
3965 * @dflags: GPIO initialization flags
3966 * @label: label to attach to the requested GPIO
3968 * This function can be used for drivers that get their configuration
3969 * from opaque firmware.
3971 * The function properly finds the corresponding GPIO using whatever is the
3972 * underlying firmware interface and then makes sure that the GPIO
3973 * descriptor is requested before it is returned to the caller.
3976 * On successful request the GPIO pin is configured in accordance with
3979 * In case of error an ERR_PTR() is returned.
3981 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
3982 const char *propname, int index,
3983 enum gpiod_flags dflags,
3986 unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
3987 struct gpio_desc *desc = ERR_PTR(-ENODEV);
3990 if (is_of_node(fwnode)) {
3991 desc = gpiod_get_from_of_node(to_of_node(fwnode),
3996 } else if (is_acpi_node(fwnode)) {
3997 struct acpi_gpio_info info;
3999 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4003 acpi_gpio_update_gpiod_flags(&dflags, &info);
4004 acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
4006 return ERR_PTR(-EINVAL);
4008 /* Currently only ACPI takes this path */
4009 ret = gpiod_request(desc, label);
4011 return ERR_PTR(ret);
4013 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4016 return ERR_PTR(ret);
4019 blocking_notifier_call_chain(&desc->gdev->notifier,
4020 GPIOLINE_CHANGED_REQUESTED, desc);
4024 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4027 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4029 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4030 * @con_id: function within the GPIO consumer
4031 * @index: index of the GPIO to obtain in the consumer
4032 * @flags: optional GPIO initialization flags
4034 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4035 * specified index was assigned to the requested function it will return NULL.
4036 * This is convenient for drivers that need to handle optional GPIOs.
4038 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4041 enum gpiod_flags flags)
4043 struct gpio_desc *desc;
4045 desc = gpiod_get_index(dev, con_id, index, flags);
4046 if (gpiod_not_found(desc))
4051 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4054 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4055 * @desc: gpio whose value will be assigned
4056 * @name: gpio line name
4057 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4058 * of_find_gpio() or of_get_gpio_hog()
4059 * @dflags: gpiod_flags - optional GPIO initialization flags
4061 int gpiod_hog(struct gpio_desc *desc, const char *name,
4062 unsigned long lflags, enum gpiod_flags dflags)
4064 struct gpio_chip *gc;
4065 struct gpio_desc *local_desc;
4069 gc = gpiod_to_chip(desc);
4070 hwnum = gpio_chip_hwgpio(desc);
4072 local_desc = gpiochip_request_own_desc(gc, hwnum, name,
4074 if (IS_ERR(local_desc)) {
4075 ret = PTR_ERR(local_desc);
4076 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4077 name, gc->label, hwnum, ret);
4081 /* Mark GPIO as hogged so it can be identified and removed later */
4082 set_bit(FLAG_IS_HOGGED, &desc->flags);
4084 gpiod_info(desc, "hogged as %s%s\n",
4085 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4086 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
4087 (dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : "");
4093 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4094 * @gc: gpio chip to act on
4096 static void gpiochip_free_hogs(struct gpio_chip *gc)
4100 for (id = 0; id < gc->ngpio; id++) {
4101 if (test_bit(FLAG_IS_HOGGED, &gc->gpiodev->descs[id].flags))
4102 gpiochip_free_own_desc(&gc->gpiodev->descs[id]);
4107 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4108 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4109 * @con_id: function within the GPIO consumer
4110 * @flags: optional GPIO initialization flags
4112 * This function acquires all the GPIOs defined under a given function.
4114 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4115 * no GPIO has been assigned to the requested function, or another IS_ERR()
4116 * code if an error occurred while trying to acquire the GPIOs.
4118 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4120 enum gpiod_flags flags)
4122 struct gpio_desc *desc;
4123 struct gpio_descs *descs;
4124 struct gpio_array *array_info = NULL;
4125 struct gpio_chip *gc;
4126 int count, bitmap_size;
4128 count = gpiod_count(dev, con_id);
4130 return ERR_PTR(count);
4132 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4134 return ERR_PTR(-ENOMEM);
4136 for (descs->ndescs = 0; descs->ndescs < count; ) {
4137 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4139 gpiod_put_array(descs);
4140 return ERR_CAST(desc);
4143 descs->desc[descs->ndescs] = desc;
4145 gc = gpiod_to_chip(desc);
4147 * If pin hardware number of array member 0 is also 0, select
4148 * its chip as a candidate for fast bitmap processing path.
4150 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4151 struct gpio_descs *array;
4153 bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?
4156 array = kzalloc(struct_size(descs, desc, count) +
4157 struct_size(array_info, invert_mask,
4158 3 * bitmap_size), GFP_KERNEL);
4160 gpiod_put_array(descs);
4161 return ERR_PTR(-ENOMEM);
4164 memcpy(array, descs,
4165 struct_size(descs, desc, descs->ndescs + 1));
4169 array_info = (void *)(descs->desc + count);
4170 array_info->get_mask = array_info->invert_mask +
4172 array_info->set_mask = array_info->get_mask +
4175 array_info->desc = descs->desc;
4176 array_info->size = count;
4177 array_info->chip = gc;
4178 bitmap_set(array_info->get_mask, descs->ndescs,
4179 count - descs->ndescs);
4180 bitmap_set(array_info->set_mask, descs->ndescs,
4181 count - descs->ndescs);
4182 descs->info = array_info;
4184 /* Unmark array members which don't belong to the 'fast' chip */
4185 if (array_info && array_info->chip != gc) {
4186 __clear_bit(descs->ndescs, array_info->get_mask);
4187 __clear_bit(descs->ndescs, array_info->set_mask);
4190 * Detect array members which belong to the 'fast' chip
4191 * but their pins are not in hardware order.
4193 else if (array_info &&
4194 gpio_chip_hwgpio(desc) != descs->ndescs) {
4196 * Don't use fast path if all array members processed so
4197 * far belong to the same chip as this one but its pin
4198 * hardware number is different from its array index.
4200 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4203 __clear_bit(descs->ndescs,
4204 array_info->get_mask);
4205 __clear_bit(descs->ndescs,
4206 array_info->set_mask);
4208 } else if (array_info) {
4209 /* Exclude open drain or open source from fast output */
4210 if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||
4211 gpiochip_line_is_open_source(gc, descs->ndescs))
4212 __clear_bit(descs->ndescs,
4213 array_info->set_mask);
4214 /* Identify 'fast' pins which require invertion */
4215 if (gpiod_is_active_low(desc))
4216 __set_bit(descs->ndescs,
4217 array_info->invert_mask);
4224 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4225 array_info->chip->label, array_info->size,
4226 *array_info->get_mask, *array_info->set_mask,
4227 *array_info->invert_mask);
4230 EXPORT_SYMBOL_GPL(gpiod_get_array);
4233 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4235 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4236 * @con_id: function within the GPIO consumer
4237 * @flags: optional GPIO initialization flags
4239 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4240 * assigned to the requested function it will return NULL.
4242 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4244 enum gpiod_flags flags)
4246 struct gpio_descs *descs;
4248 descs = gpiod_get_array(dev, con_id, flags);
4249 if (gpiod_not_found(descs))
4254 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4257 * gpiod_put - dispose of a GPIO descriptor
4258 * @desc: GPIO descriptor to dispose of
4260 * No descriptor can be used after gpiod_put() has been called on it.
4262 void gpiod_put(struct gpio_desc *desc)
4267 EXPORT_SYMBOL_GPL(gpiod_put);
4270 * gpiod_put_array - dispose of multiple GPIO descriptors
4271 * @descs: struct gpio_descs containing an array of descriptors
4273 void gpiod_put_array(struct gpio_descs *descs)
4277 for (i = 0; i < descs->ndescs; i++)
4278 gpiod_put(descs->desc[i]);
4282 EXPORT_SYMBOL_GPL(gpiod_put_array);
4285 static int gpio_bus_match(struct device *dev, struct device_driver *drv)
4287 struct fwnode_handle *fwnode = dev_fwnode(dev);
4290 * Only match if the fwnode doesn't already have a proper struct device
4293 if (fwnode && fwnode->dev != dev)
4298 static int gpio_stub_drv_probe(struct device *dev)
4301 * The DT node of some GPIO chips have a "compatible" property, but
4302 * never have a struct device added and probed by a driver to register
4303 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
4304 * the consumers of the GPIO chip to get probe deferred forever because
4305 * they will be waiting for a device associated with the GPIO chip
4306 * firmware node to get added and bound to a driver.
4308 * To allow these consumers to probe, we associate the struct
4309 * gpio_device of the GPIO chip with the firmware node and then simply
4310 * bind it to this stub driver.
4315 static struct device_driver gpio_stub_drv = {
4316 .name = "gpio_stub_drv",
4317 .bus = &gpio_bus_type,
4318 .probe = gpio_stub_drv_probe,
4321 static int __init gpiolib_dev_init(void)
4325 /* Register GPIO sysfs bus */
4326 ret = bus_register(&gpio_bus_type);
4328 pr_err("gpiolib: could not register GPIO bus type\n");
4332 ret = driver_register(&gpio_stub_drv);
4334 pr_err("gpiolib: could not register GPIO stub driver\n");
4335 bus_unregister(&gpio_bus_type);
4339 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
4341 pr_err("gpiolib: failed to allocate char dev region\n");
4342 driver_unregister(&gpio_stub_drv);
4343 bus_unregister(&gpio_bus_type);
4347 gpiolib_initialized = true;
4348 gpiochip_setup_devs();
4350 #if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
4351 WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
4352 #endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
4356 core_initcall(gpiolib_dev_init);
4358 #ifdef CONFIG_DEBUG_FS
4360 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4363 struct gpio_chip *gc = gdev->chip;
4364 unsigned gpio = gdev->base;
4365 struct gpio_desc *gdesc = &gdev->descs[0];
4370 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4371 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4373 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4379 gpiod_get_direction(gdesc);
4380 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4381 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4382 active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
4383 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
4384 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4385 is_out ? "out" : "in ",
4386 gc->get ? (gc->get(gc, i) ? "hi" : "lo") : "? ",
4387 is_irq ? "IRQ " : "",
4388 active_low ? "ACTIVE LOW" : "");
4389 seq_printf(s, "\n");
4393 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4395 unsigned long flags;
4396 struct gpio_device *gdev = NULL;
4397 loff_t index = *pos;
4401 spin_lock_irqsave(&gpio_lock, flags);
4402 list_for_each_entry(gdev, &gpio_devices, list)
4404 spin_unlock_irqrestore(&gpio_lock, flags);
4407 spin_unlock_irqrestore(&gpio_lock, flags);
4412 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4414 unsigned long flags;
4415 struct gpio_device *gdev = v;
4418 spin_lock_irqsave(&gpio_lock, flags);
4419 if (list_is_last(&gdev->list, &gpio_devices))
4422 ret = list_entry(gdev->list.next, struct gpio_device, list);
4423 spin_unlock_irqrestore(&gpio_lock, flags);
4431 static void gpiolib_seq_stop(struct seq_file *s, void *v)
4435 static int gpiolib_seq_show(struct seq_file *s, void *v)
4437 struct gpio_device *gdev = v;
4438 struct gpio_chip *gc = gdev->chip;
4439 struct device *parent;
4442 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4443 dev_name(&gdev->dev));
4447 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4448 dev_name(&gdev->dev),
4449 gdev->base, gdev->base + gdev->ngpio - 1);
4450 parent = gc->parent;
4452 seq_printf(s, ", parent: %s/%s",
4453 parent->bus ? parent->bus->name : "no-bus",
4456 seq_printf(s, ", %s", gc->label);
4458 seq_printf(s, ", can sleep");
4459 seq_printf(s, ":\n");
4462 gc->dbg_show(s, gc);
4464 gpiolib_dbg_show(s, gdev);
4469 static const struct seq_operations gpiolib_sops = {
4470 .start = gpiolib_seq_start,
4471 .next = gpiolib_seq_next,
4472 .stop = gpiolib_seq_stop,
4473 .show = gpiolib_seq_show,
4475 DEFINE_SEQ_ATTRIBUTE(gpiolib);
4477 static int __init gpiolib_debugfs_init(void)
4479 /* /sys/kernel/debug/gpio */
4480 debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);
4483 subsys_initcall(gpiolib_debugfs_init);
4485 #endif /* DEBUG_FS */