1 #include <linux/kernel.h>
2 #include <linux/module.h>
3 #include <linux/interrupt.h>
5 #include <linux/spinlock.h>
6 #include <linux/list.h>
7 #include <linux/device.h>
9 #include <linux/debugfs.h>
10 #include <linux/seq_file.h>
11 #include <linux/gpio.h>
12 #include <linux/of_gpio.h>
13 #include <linux/idr.h>
14 #include <linux/slab.h>
15 #include <linux/acpi.h>
16 #include <linux/gpio/driver.h>
17 #include <linux/gpio/machine.h>
18 #include <linux/pinctrl/consumer.h>
19 #include <linux/idr.h>
20 #include <linux/cdev.h>
22 #include <linux/uaccess.h>
23 #include <linux/compat.h>
24 #include <uapi/linux/gpio.h>
28 #define CREATE_TRACE_POINTS
29 #include <trace/events/gpio.h>
31 /* Implementation infrastructure for GPIO interfaces.
33 * The GPIO programming interface allows for inlining speed-critical
34 * get/set operations for common cases, so that access to SOC-integrated
35 * GPIOs can sometimes cost only an instruction or two per bit.
39 /* When debugging, extend minimal trust to callers and platform code.
40 * Also emit diagnostic messages that may help initial bringup, when
41 * board setup or driver bugs are most common.
43 * Otherwise, minimize overhead in what may be bitbanging codepaths.
46 #define extra_checks 1
48 #define extra_checks 0
51 /* Device and char device-related information */
52 static DEFINE_IDA(gpio_ida);
53 static dev_t gpio_devt;
54 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
55 static struct bus_type gpio_bus_type = {
59 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
60 * While any GPIO is requested, its gpio_chip is not removable;
61 * each GPIO's "requested" flag serves as a lock and refcount.
63 DEFINE_SPINLOCK(gpio_lock);
65 static DEFINE_MUTEX(gpio_lookup_lock);
66 static LIST_HEAD(gpio_lookup_list);
67 LIST_HEAD(gpio_devices);
69 static void gpiochip_free_hogs(struct gpio_chip *chip);
70 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
72 static bool gpiolib_initialized;
74 static inline void desc_set_label(struct gpio_desc *d, const char *label)
80 * Convert a GPIO number to its descriptor
82 struct gpio_desc *gpio_to_desc(unsigned gpio)
84 struct gpio_device *gdev;
87 spin_lock_irqsave(&gpio_lock, flags);
89 list_for_each_entry(gdev, &gpio_devices, list) {
90 if (gdev->base <= gpio &&
91 gdev->base + gdev->ngpio > gpio) {
92 spin_unlock_irqrestore(&gpio_lock, flags);
93 return &gdev->descs[gpio - gdev->base];
97 spin_unlock_irqrestore(&gpio_lock, flags);
99 if (!gpio_is_valid(gpio))
100 WARN(1, "invalid GPIO %d\n", gpio);
104 EXPORT_SYMBOL_GPL(gpio_to_desc);
107 * Get the GPIO descriptor corresponding to the given hw number for this chip.
109 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
112 struct gpio_device *gdev = chip->gpiodev;
114 if (hwnum >= gdev->ngpio)
115 return ERR_PTR(-EINVAL);
117 return &gdev->descs[hwnum];
121 * Convert a GPIO descriptor to the integer namespace.
122 * This should disappear in the future but is needed since we still
123 * use GPIO numbers for error messages and sysfs nodes
125 int desc_to_gpio(const struct gpio_desc *desc)
127 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
129 EXPORT_SYMBOL_GPL(desc_to_gpio);
133 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
134 * @desc: descriptor to return the chip of
136 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
138 if (!desc || !desc->gdev || !desc->gdev->chip)
140 return desc->gdev->chip;
142 EXPORT_SYMBOL_GPL(gpiod_to_chip);
144 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
145 static int gpiochip_find_base(int ngpio)
147 struct gpio_device *gdev;
148 int base = ARCH_NR_GPIOS - ngpio;
150 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
151 /* found a free space? */
152 if (gdev->base + gdev->ngpio <= base)
155 /* nope, check the space right before the chip */
156 base = gdev->base - ngpio;
159 if (gpio_is_valid(base)) {
160 pr_debug("%s: found new base at %d\n", __func__, base);
163 pr_err("%s: cannot find free range\n", __func__);
169 * gpiod_get_direction - return the current direction of a GPIO
170 * @desc: GPIO to get the direction of
172 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
174 * This function may sleep if gpiod_cansleep() is true.
176 int gpiod_get_direction(struct gpio_desc *desc)
178 struct gpio_chip *chip;
180 int status = -EINVAL;
182 chip = gpiod_to_chip(desc);
183 offset = gpio_chip_hwgpio(desc);
185 if (!chip->get_direction)
188 status = chip->get_direction(chip, offset);
190 /* GPIOF_DIR_IN, or other positive */
192 clear_bit(FLAG_IS_OUT, &desc->flags);
196 set_bit(FLAG_IS_OUT, &desc->flags);
200 EXPORT_SYMBOL_GPL(gpiod_get_direction);
203 * Add a new chip to the global chips list, keeping the list of chips sorted
204 * by range(means [base, base + ngpio - 1]) order.
206 * Return -EBUSY if the new chip overlaps with some other chip's integer
209 static int gpiodev_add_to_list(struct gpio_device *gdev)
211 struct gpio_device *prev, *next;
213 if (list_empty(&gpio_devices)) {
214 /* initial entry in list */
215 list_add_tail(&gdev->list, &gpio_devices);
219 next = list_entry(gpio_devices.next, struct gpio_device, list);
220 if (gdev->base + gdev->ngpio <= next->base) {
221 /* add before first entry */
222 list_add(&gdev->list, &gpio_devices);
226 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
227 if (prev->base + prev->ngpio <= gdev->base) {
228 /* add behind last entry */
229 list_add_tail(&gdev->list, &gpio_devices);
233 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
234 /* at the end of the list */
235 if (&next->list == &gpio_devices)
238 /* add between prev and next */
239 if (prev->base + prev->ngpio <= gdev->base
240 && gdev->base + gdev->ngpio <= next->base) {
241 list_add(&gdev->list, &prev->list);
246 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
251 * Convert a GPIO name to its descriptor
253 static struct gpio_desc *gpio_name_to_desc(const char * const name)
255 struct gpio_device *gdev;
258 spin_lock_irqsave(&gpio_lock, flags);
260 list_for_each_entry(gdev, &gpio_devices, list) {
263 for (i = 0; i != gdev->ngpio; ++i) {
264 struct gpio_desc *desc = &gdev->descs[i];
266 if (!desc->name || !name)
269 if (!strcmp(desc->name, name)) {
270 spin_unlock_irqrestore(&gpio_lock, flags);
276 spin_unlock_irqrestore(&gpio_lock, flags);
282 * Takes the names from gc->names and checks if they are all unique. If they
283 * are, they are assigned to their gpio descriptors.
285 * Warning if one of the names is already used for a different GPIO.
287 static int gpiochip_set_desc_names(struct gpio_chip *gc)
289 struct gpio_device *gdev = gc->gpiodev;
295 /* First check all names if they are unique */
296 for (i = 0; i != gc->ngpio; ++i) {
297 struct gpio_desc *gpio;
299 gpio = gpio_name_to_desc(gc->names[i]);
302 "Detected name collision for GPIO name '%s'\n",
306 /* Then add all names to the GPIO descriptors */
307 for (i = 0; i != gc->ngpio; ++i)
308 gdev->descs[i].name = gc->names[i];
314 * gpio_ioctl() - ioctl handler for the GPIO chardev
316 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
318 struct gpio_device *gdev = filp->private_data;
319 struct gpio_chip *chip = gdev->chip;
320 void __user *ip = (void __user *)arg;
322 /* We fail any subsequent ioctl():s when the chip is gone */
326 /* Fill in the struct and pass to userspace */
327 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
328 struct gpiochip_info chipinfo;
330 strncpy(chipinfo.name, dev_name(&gdev->dev),
331 sizeof(chipinfo.name));
332 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
333 strncpy(chipinfo.label, gdev->label,
334 sizeof(chipinfo.label));
335 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
336 chipinfo.lines = gdev->ngpio;
337 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
340 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
341 struct gpioline_info lineinfo;
342 struct gpio_desc *desc;
344 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
346 if (lineinfo.line_offset > gdev->ngpio)
349 desc = &gdev->descs[lineinfo.line_offset];
351 strncpy(lineinfo.name, desc->name,
352 sizeof(lineinfo.name));
353 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
355 lineinfo.name[0] = '\0';
358 strncpy(lineinfo.consumer, desc->label,
359 sizeof(lineinfo.consumer));
360 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
362 lineinfo.consumer[0] = '\0';
366 * Userspace only need to know that the kernel is using
367 * this GPIO so it can't use it.
370 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
371 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
372 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
373 test_bit(FLAG_EXPORT, &desc->flags) ||
374 test_bit(FLAG_SYSFS, &desc->flags))
375 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
376 if (test_bit(FLAG_IS_OUT, &desc->flags))
377 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
378 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
379 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
380 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
381 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
382 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
383 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
385 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
393 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
396 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
401 * gpio_chrdev_open() - open the chardev for ioctl operations
402 * @inode: inode for this chardev
403 * @filp: file struct for storing private data
404 * Returns 0 on success
406 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
408 struct gpio_device *gdev = container_of(inode->i_cdev,
409 struct gpio_device, chrdev);
411 /* Fail on open if the backing gpiochip is gone */
412 if (!gdev || !gdev->chip)
414 get_device(&gdev->dev);
415 filp->private_data = gdev;
420 * gpio_chrdev_release() - close chardev after ioctl operations
421 * @inode: inode for this chardev
422 * @filp: file struct for storing private data
423 * Returns 0 on success
425 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
427 struct gpio_device *gdev = container_of(inode->i_cdev,
428 struct gpio_device, chrdev);
432 put_device(&gdev->dev);
437 static const struct file_operations gpio_fileops = {
438 .release = gpio_chrdev_release,
439 .open = gpio_chrdev_open,
440 .owner = THIS_MODULE,
441 .llseek = noop_llseek,
442 .unlocked_ioctl = gpio_ioctl,
444 .compat_ioctl = gpio_ioctl_compat,
448 static void gpiodevice_release(struct device *dev)
450 struct gpio_device *gdev = dev_get_drvdata(dev);
452 list_del(&gdev->list);
453 ida_simple_remove(&gpio_ida, gdev->id);
459 static int gpiochip_setup_dev(struct gpio_device *gdev)
463 cdev_init(&gdev->chrdev, &gpio_fileops);
464 gdev->chrdev.owner = THIS_MODULE;
465 gdev->chrdev.kobj.parent = &gdev->dev.kobj;
466 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
467 status = cdev_add(&gdev->chrdev, gdev->dev.devt, 1);
469 chip_warn(gdev->chip, "failed to add char device %d:%d\n",
470 MAJOR(gpio_devt), gdev->id);
472 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
473 MAJOR(gpio_devt), gdev->id);
474 status = device_add(&gdev->dev);
476 goto err_remove_chardev;
478 status = gpiochip_sysfs_register(gdev);
480 goto err_remove_device;
482 /* From this point, the .release() function cleans up gpio_device */
483 gdev->dev.release = gpiodevice_release;
484 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
485 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
486 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
491 device_del(&gdev->dev);
493 cdev_del(&gdev->chrdev);
497 static void gpiochip_setup_devs(void)
499 struct gpio_device *gdev;
502 list_for_each_entry(gdev, &gpio_devices, list) {
503 err = gpiochip_setup_dev(gdev);
505 pr_err("%s: Failed to initialize gpio device (%d)\n",
506 dev_name(&gdev->dev), err);
511 * gpiochip_add_data() - register a gpio_chip
512 * @chip: the chip to register, with chip->base initialized
513 * Context: potentially before irqs will work
515 * Returns a negative errno if the chip can't be registered, such as
516 * because the chip->base is invalid or already associated with a
517 * different chip. Otherwise it returns zero as a success code.
519 * When gpiochip_add_data() is called very early during boot, so that GPIOs
520 * can be freely used, the chip->parent device must be registered before
521 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
522 * for GPIOs will fail rudely.
524 * gpiochip_add_data() must only be called after gpiolib initialization,
525 * ie after core_initcall().
527 * If chip->base is negative, this requests dynamic assignment of
528 * a range of valid GPIOs.
530 int gpiochip_add_data(struct gpio_chip *chip, void *data)
535 int base = chip->base;
536 struct gpio_device *gdev;
539 * First: allocate and populate the internal stat container, and
540 * set up the struct device.
542 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
545 gdev->dev.bus = &gpio_bus_type;
547 chip->gpiodev = gdev;
549 gdev->dev.parent = chip->parent;
550 gdev->dev.of_node = chip->parent->of_node;
552 #ifdef CONFIG_OF_GPIO
553 /* If the gpiochip has an assigned OF node this takes precedence */
555 gdev->dev.of_node = chip->of_node;
558 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
563 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
564 device_initialize(&gdev->dev);
565 dev_set_drvdata(&gdev->dev, gdev);
566 if (chip->parent && chip->parent->driver)
567 gdev->owner = chip->parent->driver->owner;
568 else if (chip->owner)
569 /* TODO: remove chip->owner */
570 gdev->owner = chip->owner;
572 gdev->owner = THIS_MODULE;
574 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
580 if (chip->ngpio == 0) {
581 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
587 gdev->label = kstrdup(chip->label, GFP_KERNEL);
589 gdev->label = kstrdup("unknown", GFP_KERNEL);
595 gdev->ngpio = chip->ngpio;
598 spin_lock_irqsave(&gpio_lock, flags);
601 * TODO: this allocates a Linux GPIO number base in the global
602 * GPIO numberspace for this chip. In the long run we want to
603 * get *rid* of this numberspace and use only descriptors, but
604 * it may be a pipe dream. It will not happen before we get rid
605 * of the sysfs interface anyways.
608 base = gpiochip_find_base(chip->ngpio);
611 spin_unlock_irqrestore(&gpio_lock, flags);
615 * TODO: it should not be necessary to reflect the assigned
616 * base outside of the GPIO subsystem. Go over drivers and
617 * see if anyone makes use of this, else drop this and assign
624 status = gpiodev_add_to_list(gdev);
626 spin_unlock_irqrestore(&gpio_lock, flags);
630 spin_unlock_irqrestore(&gpio_lock, flags);
632 for (i = 0; i < chip->ngpio; i++) {
633 struct gpio_desc *desc = &gdev->descs[i];
637 * REVISIT: most hardware initializes GPIOs as inputs
638 * (often with pullups enabled) so power usage is
639 * minimized. Linux code should set the gpio direction
640 * first thing; but until it does, and in case
641 * chip->get_direction is not set, we may expose the
642 * wrong direction in sysfs.
645 if (chip->get_direction) {
647 * If we have .get_direction, set up the initial
648 * direction flag from the hardware.
650 int dir = chip->get_direction(chip, i);
653 set_bit(FLAG_IS_OUT, &desc->flags);
654 } else if (!chip->direction_input) {
656 * If the chip lacks the .direction_input callback
657 * we logically assume all lines are outputs.
659 set_bit(FLAG_IS_OUT, &desc->flags);
663 #ifdef CONFIG_PINCTRL
664 INIT_LIST_HEAD(&gdev->pin_ranges);
667 status = gpiochip_set_desc_names(chip);
669 goto err_remove_from_list;
671 status = of_gpiochip_add(chip);
673 goto err_remove_chip;
675 acpi_gpiochip_add(chip);
678 * By first adding the chardev, and then adding the device,
679 * we get a device node entry in sysfs under
680 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
681 * coldplug of device nodes and other udev business.
682 * We can do this only if gpiolib has been initialized.
683 * Otherwise, defer until later.
685 if (gpiolib_initialized) {
686 status = gpiochip_setup_dev(gdev);
688 goto err_remove_chip;
693 acpi_gpiochip_remove(chip);
694 gpiochip_free_hogs(chip);
695 of_gpiochip_remove(chip);
696 err_remove_from_list:
697 spin_lock_irqsave(&gpio_lock, flags);
698 list_del(&gdev->list);
699 spin_unlock_irqrestore(&gpio_lock, flags);
705 ida_simple_remove(&gpio_ida, gdev->id);
706 /* failures here can mean systems won't boot... */
707 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
708 gdev->base, gdev->base + gdev->ngpio - 1,
709 chip->label ? : "generic");
713 EXPORT_SYMBOL_GPL(gpiochip_add_data);
716 * gpiochip_get_data() - get per-subdriver data for the chip
718 void *gpiochip_get_data(struct gpio_chip *chip)
720 return chip->gpiodev->data;
722 EXPORT_SYMBOL_GPL(gpiochip_get_data);
725 * gpiochip_remove() - unregister a gpio_chip
726 * @chip: the chip to unregister
728 * A gpio_chip with any GPIOs still requested may not be removed.
730 void gpiochip_remove(struct gpio_chip *chip)
732 struct gpio_device *gdev = chip->gpiodev;
733 struct gpio_desc *desc;
736 bool requested = false;
738 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
739 gpiochip_sysfs_unregister(gdev);
740 /* Numb the device, cancelling all outstanding operations */
742 gpiochip_irqchip_remove(chip);
743 acpi_gpiochip_remove(chip);
744 gpiochip_remove_pin_ranges(chip);
745 gpiochip_free_hogs(chip);
746 of_gpiochip_remove(chip);
748 * We accept no more calls into the driver from this point, so
749 * NULL the driver data pointer
753 spin_lock_irqsave(&gpio_lock, flags);
754 for (i = 0; i < gdev->ngpio; i++) {
755 desc = &gdev->descs[i];
756 if (test_bit(FLAG_REQUESTED, &desc->flags))
759 spin_unlock_irqrestore(&gpio_lock, flags);
763 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
766 * The gpiochip side puts its use of the device to rest here:
767 * if there are no userspace clients, the chardev and device will
768 * be removed, else it will be dangling until the last user is
771 cdev_del(&gdev->chrdev);
772 device_del(&gdev->dev);
773 put_device(&gdev->dev);
775 EXPORT_SYMBOL_GPL(gpiochip_remove);
777 static void devm_gpio_chip_release(struct device *dev, void *res)
779 struct gpio_chip *chip = *(struct gpio_chip **)res;
781 gpiochip_remove(chip);
784 static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
787 struct gpio_chip **r = res;
798 * devm_gpiochip_add_data() - Resource manager piochip_add_data()
799 * @dev: the device pointer on which irq_chip belongs to.
800 * @chip: the chip to register, with chip->base initialized
801 * Context: potentially before irqs will work
803 * Returns a negative errno if the chip can't be registered, such as
804 * because the chip->base is invalid or already associated with a
805 * different chip. Otherwise it returns zero as a success code.
807 * The gpio chip automatically be released when the device is unbound.
809 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
812 struct gpio_chip **ptr;
815 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
820 ret = gpiochip_add_data(chip, data);
827 devres_add(dev, ptr);
831 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
834 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
835 * @dev: device for which which resource was allocated
836 * @chip: the chip to remove
838 * A gpio_chip with any GPIOs still requested may not be removed.
840 void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
844 ret = devres_release(dev, devm_gpio_chip_release,
845 devm_gpio_chip_match, chip);
849 EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
852 * gpiochip_find() - iterator for locating a specific gpio_chip
853 * @data: data to pass to match function
854 * @callback: Callback function to check gpio_chip
856 * Similar to bus_find_device. It returns a reference to a gpio_chip as
857 * determined by a user supplied @match callback. The callback should return
858 * 0 if the device doesn't match and non-zero if it does. If the callback is
859 * non-zero, this function will return to the caller and not iterate over any
862 struct gpio_chip *gpiochip_find(void *data,
863 int (*match)(struct gpio_chip *chip,
866 struct gpio_device *gdev;
867 struct gpio_chip *chip;
870 spin_lock_irqsave(&gpio_lock, flags);
871 list_for_each_entry(gdev, &gpio_devices, list)
872 if (gdev->chip && match(gdev->chip, data))
876 if (&gdev->list == &gpio_devices)
881 spin_unlock_irqrestore(&gpio_lock, flags);
885 EXPORT_SYMBOL_GPL(gpiochip_find);
887 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
889 const char *name = data;
891 return !strcmp(chip->label, name);
894 static struct gpio_chip *find_chip_by_name(const char *name)
896 return gpiochip_find((void *)name, gpiochip_match_name);
899 #ifdef CONFIG_GPIOLIB_IRQCHIP
902 * The following is irqchip helper code for gpiochips.
906 * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
907 * @gpiochip: the gpiochip to set the irqchip chain to
908 * @irqchip: the irqchip to chain to the gpiochip
909 * @parent_irq: the irq number corresponding to the parent IRQ for this
911 * @parent_handler: the parent interrupt handler for the accumulated IRQ
912 * coming out of the gpiochip. If the interrupt is nested rather than
913 * cascaded, pass NULL in this handler argument
915 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
916 struct irq_chip *irqchip,
918 irq_flow_handler_t parent_handler)
922 if (!gpiochip->irqdomain) {
923 chip_err(gpiochip, "called %s before setting up irqchip\n",
928 if (parent_handler) {
929 if (gpiochip->can_sleep) {
931 "you cannot have chained interrupts on a "
932 "chip that may sleep\n");
936 * The parent irqchip is already using the chip_data for this
937 * irqchip, so our callbacks simply use the handler_data.
939 irq_set_chained_handler_and_data(parent_irq, parent_handler,
942 gpiochip->irq_parent = parent_irq;
945 /* Set the parent IRQ for all affected IRQs */
946 for (offset = 0; offset < gpiochip->ngpio; offset++)
947 irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
950 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
953 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
954 * @d: the irqdomain used by this irqchip
955 * @irq: the global irq number used by this GPIO irqchip irq
956 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
958 * This function will set up the mapping for a certain IRQ line on a
959 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
960 * stored inside the gpiochip.
962 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
963 irq_hw_number_t hwirq)
965 struct gpio_chip *chip = d->host_data;
967 irq_set_chip_data(irq, chip);
969 * This lock class tells lockdep that GPIO irqs are in a different
970 * category than their parents, so it won't report false recursion.
972 irq_set_lockdep_class(irq, chip->lock_key);
973 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
974 /* Chips that can sleep need nested thread handlers */
975 if (chip->can_sleep && !chip->irq_not_threaded)
976 irq_set_nested_thread(irq, 1);
977 irq_set_noprobe(irq);
980 * No set-up of the hardware will happen if IRQ_TYPE_NONE
981 * is passed as default type.
983 if (chip->irq_default_type != IRQ_TYPE_NONE)
984 irq_set_irq_type(irq, chip->irq_default_type);
989 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
991 struct gpio_chip *chip = d->host_data;
994 irq_set_nested_thread(irq, 0);
995 irq_set_chip_and_handler(irq, NULL, NULL);
996 irq_set_chip_data(irq, NULL);
999 static const struct irq_domain_ops gpiochip_domain_ops = {
1000 .map = gpiochip_irq_map,
1001 .unmap = gpiochip_irq_unmap,
1002 /* Virtually all GPIO irqchips are twocell:ed */
1003 .xlate = irq_domain_xlate_twocell,
1006 static int gpiochip_irq_reqres(struct irq_data *d)
1008 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1010 if (!try_module_get(chip->gpiodev->owner))
1013 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
1015 "unable to lock HW IRQ %lu for IRQ\n",
1017 module_put(chip->gpiodev->owner);
1023 static void gpiochip_irq_relres(struct irq_data *d)
1025 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1027 gpiochip_unlock_as_irq(chip, d->hwirq);
1028 module_put(chip->gpiodev->owner);
1031 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1033 return irq_find_mapping(chip->irqdomain, offset);
1037 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1038 * @gpiochip: the gpiochip to remove the irqchip from
1040 * This is called only from gpiochip_remove()
1042 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1044 unsigned int offset;
1046 acpi_gpiochip_free_interrupts(gpiochip);
1048 if (gpiochip->irq_parent) {
1049 irq_set_chained_handler(gpiochip->irq_parent, NULL);
1050 irq_set_handler_data(gpiochip->irq_parent, NULL);
1053 /* Remove all IRQ mappings and delete the domain */
1054 if (gpiochip->irqdomain) {
1055 for (offset = 0; offset < gpiochip->ngpio; offset++)
1056 irq_dispose_mapping(
1057 irq_find_mapping(gpiochip->irqdomain, offset));
1058 irq_domain_remove(gpiochip->irqdomain);
1061 if (gpiochip->irqchip) {
1062 gpiochip->irqchip->irq_request_resources = NULL;
1063 gpiochip->irqchip->irq_release_resources = NULL;
1064 gpiochip->irqchip = NULL;
1069 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
1070 * @gpiochip: the gpiochip to add the irqchip to
1071 * @irqchip: the irqchip to add to the gpiochip
1072 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1073 * allocate gpiochip irqs from
1074 * @handler: the irq handler to use (often a predefined irq core function)
1075 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1076 * to have the core avoid setting up any default type in the hardware.
1077 * @lock_key: lockdep class
1079 * This function closely associates a certain irqchip with a certain
1080 * gpiochip, providing an irq domain to translate the local IRQs to
1081 * global irqs in the gpiolib core, and making sure that the gpiochip
1082 * is passed as chip data to all related functions. Driver callbacks
1083 * need to use gpiochip_get_data() to get their local state containers back
1084 * from the gpiochip passed as chip data. An irqdomain will be stored
1085 * in the gpiochip that shall be used by the driver to handle IRQ number
1086 * translation. The gpiochip will need to be initialized and registered
1087 * before calling this function.
1089 * This function will handle two cell:ed simple IRQs and assumes all
1090 * the pins on the gpiochip can generate a unique IRQ. Everything else
1091 * need to be open coded.
1093 int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
1094 struct irq_chip *irqchip,
1095 unsigned int first_irq,
1096 irq_flow_handler_t handler,
1098 struct lock_class_key *lock_key)
1100 struct device_node *of_node;
1101 unsigned int offset;
1102 unsigned irq_base = 0;
1104 if (!gpiochip || !irqchip)
1107 if (!gpiochip->parent) {
1108 pr_err("missing gpiochip .dev parent pointer\n");
1111 of_node = gpiochip->parent->of_node;
1112 #ifdef CONFIG_OF_GPIO
1114 * If the gpiochip has an assigned OF node this takes precedence
1115 * FIXME: get rid of this and use gpiochip->parent->of_node
1118 if (gpiochip->of_node)
1119 of_node = gpiochip->of_node;
1121 gpiochip->irqchip = irqchip;
1122 gpiochip->irq_handler = handler;
1123 gpiochip->irq_default_type = type;
1124 gpiochip->to_irq = gpiochip_to_irq;
1125 gpiochip->lock_key = lock_key;
1126 gpiochip->irqdomain = irq_domain_add_simple(of_node,
1127 gpiochip->ngpio, first_irq,
1128 &gpiochip_domain_ops, gpiochip);
1129 if (!gpiochip->irqdomain) {
1130 gpiochip->irqchip = NULL;
1135 * It is possible for a driver to override this, but only if the
1136 * alternative functions are both implemented.
1138 if (!irqchip->irq_request_resources &&
1139 !irqchip->irq_release_resources) {
1140 irqchip->irq_request_resources = gpiochip_irq_reqres;
1141 irqchip->irq_release_resources = gpiochip_irq_relres;
1145 * Prepare the mapping since the irqchip shall be orthogonal to
1146 * any gpiochip calls. If the first_irq was zero, this is
1147 * necessary to allocate descriptors for all IRQs.
1149 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1150 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
1153 * Store the base into the gpiochip to be used when
1154 * unmapping the irqs.
1156 gpiochip->irq_base = irq_base;
1159 acpi_gpiochip_request_interrupts(gpiochip);
1163 EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add);
1165 #else /* CONFIG_GPIOLIB_IRQCHIP */
1167 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
1169 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1172 * gpiochip_generic_request() - request the gpio function for a pin
1173 * @chip: the gpiochip owning the GPIO
1174 * @offset: the offset of the GPIO to request for GPIO function
1176 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
1178 return pinctrl_request_gpio(chip->gpiodev->base + offset);
1180 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1183 * gpiochip_generic_free() - free the gpio function from a pin
1184 * @chip: the gpiochip to request the gpio function for
1185 * @offset: the offset of the GPIO to free from GPIO function
1187 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
1189 pinctrl_free_gpio(chip->gpiodev->base + offset);
1191 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1193 #ifdef CONFIG_PINCTRL
1196 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1197 * @chip: the gpiochip to add the range for
1198 * @pctldev: the pin controller to map to
1199 * @gpio_offset: the start offset in the current gpio_chip number space
1200 * @pin_group: name of the pin group inside the pin controller
1202 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
1203 struct pinctrl_dev *pctldev,
1204 unsigned int gpio_offset, const char *pin_group)
1206 struct gpio_pin_range *pin_range;
1207 struct gpio_device *gdev = chip->gpiodev;
1210 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1212 chip_err(chip, "failed to allocate pin ranges\n");
1216 /* Use local offset as range ID */
1217 pin_range->range.id = gpio_offset;
1218 pin_range->range.gc = chip;
1219 pin_range->range.name = chip->label;
1220 pin_range->range.base = gdev->base + gpio_offset;
1221 pin_range->pctldev = pctldev;
1223 ret = pinctrl_get_group_pins(pctldev, pin_group,
1224 &pin_range->range.pins,
1225 &pin_range->range.npins);
1231 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1233 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1234 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1235 pinctrl_dev_get_devname(pctldev), pin_group);
1237 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1241 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1244 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1245 * @chip: the gpiochip to add the range for
1246 * @pinctrl_name: the dev_name() of the pin controller to map to
1247 * @gpio_offset: the start offset in the current gpio_chip number space
1248 * @pin_offset: the start offset in the pin controller number space
1249 * @npins: the number of pins from the offset of each pin space (GPIO and
1250 * pin controller) to accumulate in this range
1252 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
1253 unsigned int gpio_offset, unsigned int pin_offset,
1256 struct gpio_pin_range *pin_range;
1257 struct gpio_device *gdev = chip->gpiodev;
1260 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1262 chip_err(chip, "failed to allocate pin ranges\n");
1266 /* Use local offset as range ID */
1267 pin_range->range.id = gpio_offset;
1268 pin_range->range.gc = chip;
1269 pin_range->range.name = chip->label;
1270 pin_range->range.base = gdev->base + gpio_offset;
1271 pin_range->range.pin_base = pin_offset;
1272 pin_range->range.npins = npins;
1273 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1275 if (IS_ERR(pin_range->pctldev)) {
1276 ret = PTR_ERR(pin_range->pctldev);
1277 chip_err(chip, "could not create pin range\n");
1281 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1282 gpio_offset, gpio_offset + npins - 1,
1284 pin_offset, pin_offset + npins - 1);
1286 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1290 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1293 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1294 * @chip: the chip to remove all the mappings for
1296 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
1298 struct gpio_pin_range *pin_range, *tmp;
1299 struct gpio_device *gdev = chip->gpiodev;
1301 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1302 list_del(&pin_range->node);
1303 pinctrl_remove_gpio_range(pin_range->pctldev,
1308 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1310 #endif /* CONFIG_PINCTRL */
1312 /* These "optional" allocation calls help prevent drivers from stomping
1313 * on each other, and help provide better diagnostics in debugfs.
1314 * They're called even less than the "set direction" calls.
1316 static int __gpiod_request(struct gpio_desc *desc, const char *label)
1318 struct gpio_chip *chip = desc->gdev->chip;
1320 unsigned long flags;
1322 spin_lock_irqsave(&gpio_lock, flags);
1324 /* NOTE: gpio_request() can be called in early boot,
1325 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1328 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1329 desc_set_label(desc, label ? : "?");
1336 if (chip->request) {
1337 /* chip->request may sleep */
1338 spin_unlock_irqrestore(&gpio_lock, flags);
1339 status = chip->request(chip, gpio_chip_hwgpio(desc));
1340 spin_lock_irqsave(&gpio_lock, flags);
1343 desc_set_label(desc, NULL);
1344 clear_bit(FLAG_REQUESTED, &desc->flags);
1348 if (chip->get_direction) {
1349 /* chip->get_direction may sleep */
1350 spin_unlock_irqrestore(&gpio_lock, flags);
1351 gpiod_get_direction(desc);
1352 spin_lock_irqsave(&gpio_lock, flags);
1355 spin_unlock_irqrestore(&gpio_lock, flags);
1360 * This descriptor validation needs to be inserted verbatim into each
1361 * function taking a descriptor, so we need to use a preprocessor
1362 * macro to avoid endless duplication. If the desc is NULL it is an
1363 * optional GPIO and calls should just bail out.
1365 #define VALIDATE_DESC(desc) do { \
1368 if (IS_ERR(desc)) { \
1369 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
1370 return PTR_ERR(desc); \
1372 if (!desc->gdev) { \
1373 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
1376 if ( !desc->gdev->chip ) { \
1377 dev_warn(&desc->gdev->dev, \
1378 "%s: backing chip is gone\n", __func__); \
1382 #define VALIDATE_DESC_VOID(desc) do { \
1385 if (IS_ERR(desc)) { \
1386 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
1389 if (!desc->gdev) { \
1390 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
1393 if (!desc->gdev->chip) { \
1394 dev_warn(&desc->gdev->dev, \
1395 "%s: backing chip is gone\n", __func__); \
1400 int gpiod_request(struct gpio_desc *desc, const char *label)
1402 int status = -EPROBE_DEFER;
1403 struct gpio_device *gdev;
1405 VALIDATE_DESC(desc);
1408 if (try_module_get(gdev->owner)) {
1409 status = __gpiod_request(desc, label);
1411 module_put(gdev->owner);
1413 get_device(&gdev->dev);
1417 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
1422 static bool __gpiod_free(struct gpio_desc *desc)
1425 unsigned long flags;
1426 struct gpio_chip *chip;
1430 gpiod_unexport(desc);
1432 spin_lock_irqsave(&gpio_lock, flags);
1434 chip = desc->gdev->chip;
1435 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
1437 spin_unlock_irqrestore(&gpio_lock, flags);
1438 might_sleep_if(chip->can_sleep);
1439 chip->free(chip, gpio_chip_hwgpio(desc));
1440 spin_lock_irqsave(&gpio_lock, flags);
1442 desc_set_label(desc, NULL);
1443 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
1444 clear_bit(FLAG_REQUESTED, &desc->flags);
1445 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
1446 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
1447 clear_bit(FLAG_IS_HOGGED, &desc->flags);
1451 spin_unlock_irqrestore(&gpio_lock, flags);
1455 void gpiod_free(struct gpio_desc *desc)
1457 if (desc && desc->gdev && __gpiod_free(desc)) {
1458 module_put(desc->gdev->owner);
1459 put_device(&desc->gdev->dev);
1461 WARN_ON(extra_checks);
1466 * gpiochip_is_requested - return string iff signal was requested
1467 * @chip: controller managing the signal
1468 * @offset: of signal within controller's 0..(ngpio - 1) range
1470 * Returns NULL if the GPIO is not currently requested, else a string.
1471 * The string returned is the label passed to gpio_request(); if none has been
1472 * passed it is a meaningless, non-NULL constant.
1474 * This function is for use by GPIO controller drivers. The label can
1475 * help with diagnostics, and knowing that the signal is used as a GPIO
1476 * can help avoid accidentally multiplexing it to another controller.
1478 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
1480 struct gpio_desc *desc;
1482 if (offset >= chip->ngpio)
1485 desc = &chip->gpiodev->descs[offset];
1487 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
1491 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
1494 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
1495 * @desc: GPIO descriptor to request
1496 * @label: label for the GPIO
1498 * Function allows GPIO chip drivers to request and use their own GPIO
1499 * descriptors via gpiolib API. Difference to gpiod_request() is that this
1500 * function will not increase reference count of the GPIO chip module. This
1501 * allows the GPIO chip module to be unloaded as needed (we assume that the
1502 * GPIO chip driver handles freeing the GPIOs it has requested).
1504 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
1507 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
1511 chip_err(chip, "failed to get GPIO descriptor\n");
1515 err = __gpiod_request(desc, label);
1517 return ERR_PTR(err);
1521 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
1524 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
1525 * @desc: GPIO descriptor to free
1527 * Function frees the given GPIO requested previously with
1528 * gpiochip_request_own_desc().
1530 void gpiochip_free_own_desc(struct gpio_desc *desc)
1535 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
1538 * Drivers MUST set GPIO direction before making get/set calls. In
1539 * some cases this is done in early boot, before IRQs are enabled.
1541 * As a rule these aren't called more than once (except for drivers
1542 * using the open-drain emulation idiom) so these are natural places
1543 * to accumulate extra debugging checks. Note that we can't (yet)
1544 * rely on gpio_request() having been called beforehand.
1548 * gpiod_direction_input - set the GPIO direction to input
1549 * @desc: GPIO to set to input
1551 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
1552 * be called safely on it.
1554 * Return 0 in case of success, else an error code.
1556 int gpiod_direction_input(struct gpio_desc *desc)
1558 struct gpio_chip *chip;
1559 int status = -EINVAL;
1561 VALIDATE_DESC(desc);
1562 chip = desc->gdev->chip;
1564 if (!chip->get || !chip->direction_input) {
1566 "%s: missing get() or direction_input() operations\n",
1571 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
1573 clear_bit(FLAG_IS_OUT, &desc->flags);
1575 trace_gpio_direction(desc_to_gpio(desc), 1, status);
1579 EXPORT_SYMBOL_GPL(gpiod_direction_input);
1581 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1583 struct gpio_chip *gc = desc->gdev->chip;
1586 /* GPIOs used for IRQs shall not be set as output */
1587 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
1589 "%s: tried to set a GPIO tied to an IRQ as output\n",
1594 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
1595 /* First see if we can enable open drain in hardware */
1596 if (gc->set_single_ended) {
1597 ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
1598 LINE_MODE_OPEN_DRAIN);
1600 goto set_output_value;
1602 /* Emulate open drain by not actively driving the line high */
1604 return gpiod_direction_input(desc);
1606 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
1607 if (gc->set_single_ended) {
1608 ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
1609 LINE_MODE_OPEN_SOURCE);
1611 goto set_output_value;
1613 /* Emulate open source by not actively driving the line low */
1615 return gpiod_direction_input(desc);
1617 /* Make sure to disable open drain/source hardware, if any */
1618 if (gc->set_single_ended)
1619 gc->set_single_ended(gc,
1620 gpio_chip_hwgpio(desc),
1621 LINE_MODE_PUSH_PULL);
1625 if (!gc->set || !gc->direction_output) {
1627 "%s: missing set() or direction_output() operations\n",
1632 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), value);
1634 set_bit(FLAG_IS_OUT, &desc->flags);
1635 trace_gpio_value(desc_to_gpio(desc), 0, value);
1636 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
1641 * gpiod_direction_output_raw - set the GPIO direction to output
1642 * @desc: GPIO to set to output
1643 * @value: initial output value of the GPIO
1645 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1646 * be called safely on it. The initial value of the output must be specified
1647 * as raw value on the physical line without regard for the ACTIVE_LOW status.
1649 * Return 0 in case of success, else an error code.
1651 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1653 VALIDATE_DESC(desc);
1654 return _gpiod_direction_output_raw(desc, value);
1656 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
1659 * gpiod_direction_output - set the GPIO direction to output
1660 * @desc: GPIO to set to output
1661 * @value: initial output value of the GPIO
1663 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1664 * be called safely on it. The initial value of the output must be specified
1665 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1668 * Return 0 in case of success, else an error code.
1670 int gpiod_direction_output(struct gpio_desc *desc, int value)
1672 VALIDATE_DESC(desc);
1673 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1675 return _gpiod_direction_output_raw(desc, value);
1677 EXPORT_SYMBOL_GPL(gpiod_direction_output);
1680 * gpiod_set_debounce - sets @debounce time for a @gpio
1681 * @gpio: the gpio to set debounce time
1682 * @debounce: debounce time is microseconds
1684 * returns -ENOTSUPP if the controller does not support setting
1687 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
1689 struct gpio_chip *chip;
1691 VALIDATE_DESC(desc);
1692 chip = desc->gdev->chip;
1693 if (!chip->set || !chip->set_debounce) {
1695 "%s: missing set() or set_debounce() operations\n",
1700 return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);
1702 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
1705 * gpiod_is_active_low - test whether a GPIO is active-low or not
1706 * @desc: the gpio descriptor to test
1708 * Returns 1 if the GPIO is active-low, 0 otherwise.
1710 int gpiod_is_active_low(const struct gpio_desc *desc)
1712 VALIDATE_DESC(desc);
1713 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
1715 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
1717 /* I/O calls are only valid after configuration completed; the relevant
1718 * "is this a valid GPIO" error checks should already have been done.
1720 * "Get" operations are often inlinable as reading a pin value register,
1721 * and masking the relevant bit in that register.
1723 * When "set" operations are inlinable, they involve writing that mask to
1724 * one register to set a low value, or a different register to set it high.
1725 * Otherwise locking is needed, so there may be little value to inlining.
1727 *------------------------------------------------------------------------
1729 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
1730 * have requested the GPIO. That can include implicit requesting by
1731 * a direction setting call. Marking a gpio as requested locks its chip
1732 * in memory, guaranteeing that these table lookups need no more locking
1733 * and that gpiochip_remove() will fail.
1735 * REVISIT when debugging, consider adding some instrumentation to ensure
1736 * that the GPIO was actually requested.
1739 static int _gpiod_get_raw_value(const struct gpio_desc *desc)
1741 struct gpio_chip *chip;
1745 chip = desc->gdev->chip;
1746 offset = gpio_chip_hwgpio(desc);
1747 value = chip->get ? chip->get(chip, offset) : -EIO;
1748 value = value < 0 ? value : !!value;
1749 trace_gpio_value(desc_to_gpio(desc), 1, value);
1754 * gpiod_get_raw_value() - return a gpio's raw value
1755 * @desc: gpio whose value will be returned
1757 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1758 * its ACTIVE_LOW status, or negative errno on failure.
1760 * This function should be called from contexts where we cannot sleep, and will
1761 * complain if the GPIO chip functions potentially sleep.
1763 int gpiod_get_raw_value(const struct gpio_desc *desc)
1765 VALIDATE_DESC(desc);
1766 /* Should be using gpio_get_value_cansleep() */
1767 WARN_ON(desc->gdev->chip->can_sleep);
1768 return _gpiod_get_raw_value(desc);
1770 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
1773 * gpiod_get_value() - return a gpio's value
1774 * @desc: gpio whose value will be returned
1776 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1777 * account, or negative errno on failure.
1779 * This function should be called from contexts where we cannot sleep, and will
1780 * complain if the GPIO chip functions potentially sleep.
1782 int gpiod_get_value(const struct gpio_desc *desc)
1786 VALIDATE_DESC(desc);
1787 /* Should be using gpio_get_value_cansleep() */
1788 WARN_ON(desc->gdev->chip->can_sleep);
1790 value = _gpiod_get_raw_value(desc);
1794 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1799 EXPORT_SYMBOL_GPL(gpiod_get_value);
1802 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
1803 * @desc: gpio descriptor whose state need to be set.
1804 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1806 static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
1809 struct gpio_chip *chip = desc->gdev->chip;
1810 int offset = gpio_chip_hwgpio(desc);
1813 err = chip->direction_input(chip, offset);
1815 clear_bit(FLAG_IS_OUT, &desc->flags);
1817 err = chip->direction_output(chip, offset, 0);
1819 set_bit(FLAG_IS_OUT, &desc->flags);
1821 trace_gpio_direction(desc_to_gpio(desc), value, err);
1824 "%s: Error in set_value for open drain err %d\n",
1829 * _gpio_set_open_source_value() - Set the open source gpio's value.
1830 * @desc: gpio descriptor whose state need to be set.
1831 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1833 static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
1836 struct gpio_chip *chip = desc->gdev->chip;
1837 int offset = gpio_chip_hwgpio(desc);
1840 err = chip->direction_output(chip, offset, 1);
1842 set_bit(FLAG_IS_OUT, &desc->flags);
1844 err = chip->direction_input(chip, offset);
1846 clear_bit(FLAG_IS_OUT, &desc->flags);
1848 trace_gpio_direction(desc_to_gpio(desc), !value, err);
1851 "%s: Error in set_value for open source err %d\n",
1855 static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
1857 struct gpio_chip *chip;
1859 chip = desc->gdev->chip;
1860 trace_gpio_value(desc_to_gpio(desc), 0, value);
1861 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1862 _gpio_set_open_drain_value(desc, value);
1863 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1864 _gpio_set_open_source_value(desc, value);
1866 chip->set(chip, gpio_chip_hwgpio(desc), value);
1870 * set multiple outputs on the same chip;
1871 * use the chip's set_multiple function if available;
1872 * otherwise set the outputs sequentially;
1873 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
1874 * defines which outputs are to be changed
1875 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
1876 * defines the values the outputs specified by mask are to be set to
1878 static void gpio_chip_set_multiple(struct gpio_chip *chip,
1879 unsigned long *mask, unsigned long *bits)
1881 if (chip->set_multiple) {
1882 chip->set_multiple(chip, mask, bits);
1885 for (i = 0; i < chip->ngpio; i++) {
1886 if (mask[BIT_WORD(i)] == 0) {
1887 /* no more set bits in this mask word;
1888 * skip ahead to the next word */
1889 i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1;
1892 /* set outputs if the corresponding mask bit is set */
1893 if (__test_and_clear_bit(i, mask))
1894 chip->set(chip, i, test_bit(i, bits));
1899 void gpiod_set_array_value_complex(bool raw, bool can_sleep,
1900 unsigned int array_size,
1901 struct gpio_desc **desc_array,
1906 while (i < array_size) {
1907 struct gpio_chip *chip = desc_array[i]->gdev->chip;
1908 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
1909 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
1913 WARN_ON(chip->can_sleep);
1915 memset(mask, 0, sizeof(mask));
1917 struct gpio_desc *desc = desc_array[i];
1918 int hwgpio = gpio_chip_hwgpio(desc);
1919 int value = value_array[i];
1921 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1923 trace_gpio_value(desc_to_gpio(desc), 0, value);
1925 * collect all normal outputs belonging to the same chip
1926 * open drain and open source outputs are set individually
1928 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
1929 _gpio_set_open_drain_value(desc, value);
1930 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
1931 _gpio_set_open_source_value(desc, value);
1933 __set_bit(hwgpio, mask);
1935 __set_bit(hwgpio, bits);
1937 __clear_bit(hwgpio, bits);
1941 } while ((i < array_size) &&
1942 (desc_array[i]->gdev->chip == chip));
1943 /* push collected bits to outputs */
1945 gpio_chip_set_multiple(chip, mask, bits);
1950 * gpiod_set_raw_value() - assign a gpio's raw value
1951 * @desc: gpio whose value will be assigned
1952 * @value: value to assign
1954 * Set the raw value of the GPIO, i.e. the value of its physical line without
1955 * regard for its ACTIVE_LOW status.
1957 * This function should be called from contexts where we cannot sleep, and will
1958 * complain if the GPIO chip functions potentially sleep.
1960 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
1962 VALIDATE_DESC_VOID(desc);
1963 /* Should be using gpiod_set_value_cansleep() */
1964 WARN_ON(desc->gdev->chip->can_sleep);
1965 _gpiod_set_raw_value(desc, value);
1967 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
1970 * gpiod_set_value() - assign a gpio's value
1971 * @desc: gpio whose value will be assigned
1972 * @value: value to assign
1974 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1977 * This function should be called from contexts where we cannot sleep, and will
1978 * complain if the GPIO chip functions potentially sleep.
1980 void gpiod_set_value(struct gpio_desc *desc, int value)
1982 VALIDATE_DESC_VOID(desc);
1983 /* Should be using gpiod_set_value_cansleep() */
1984 WARN_ON(desc->gdev->chip->can_sleep);
1985 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1987 _gpiod_set_raw_value(desc, value);
1989 EXPORT_SYMBOL_GPL(gpiod_set_value);
1992 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
1993 * @array_size: number of elements in the descriptor / value arrays
1994 * @desc_array: array of GPIO descriptors whose values will be assigned
1995 * @value_array: array of values to assign
1997 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1998 * without regard for their ACTIVE_LOW status.
2000 * This function should be called from contexts where we cannot sleep, and will
2001 * complain if the GPIO chip functions potentially sleep.
2003 void gpiod_set_raw_array_value(unsigned int array_size,
2004 struct gpio_desc **desc_array, int *value_array)
2008 gpiod_set_array_value_complex(true, false, array_size, desc_array,
2011 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
2014 * gpiod_set_array_value() - assign values to an array of GPIOs
2015 * @array_size: number of elements in the descriptor / value arrays
2016 * @desc_array: array of GPIO descriptors whose values will be assigned
2017 * @value_array: array of values to assign
2019 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2022 * This function should be called from contexts where we cannot sleep, and will
2023 * complain if the GPIO chip functions potentially sleep.
2025 void gpiod_set_array_value(unsigned int array_size,
2026 struct gpio_desc **desc_array, int *value_array)
2030 gpiod_set_array_value_complex(false, false, array_size, desc_array,
2033 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
2036 * gpiod_cansleep() - report whether gpio value access may sleep
2037 * @desc: gpio to check
2040 int gpiod_cansleep(const struct gpio_desc *desc)
2042 VALIDATE_DESC(desc);
2043 return desc->gdev->chip->can_sleep;
2045 EXPORT_SYMBOL_GPL(gpiod_cansleep);
2048 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
2049 * @desc: gpio whose IRQ will be returned (already requested)
2051 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
2054 int gpiod_to_irq(const struct gpio_desc *desc)
2056 struct gpio_chip *chip;
2060 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
2061 * requires this function to not return zero on an invalid descriptor
2062 * but rather a negative error number.
2064 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
2067 chip = desc->gdev->chip;
2068 offset = gpio_chip_hwgpio(desc);
2070 int retirq = chip->to_irq(chip, offset);
2072 /* Zero means NO_IRQ */
2080 EXPORT_SYMBOL_GPL(gpiod_to_irq);
2083 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
2084 * @chip: the chip the GPIO to lock belongs to
2085 * @offset: the offset of the GPIO to lock as IRQ
2087 * This is used directly by GPIO drivers that want to lock down
2088 * a certain GPIO line to be used for IRQs.
2090 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
2092 struct gpio_desc *desc;
2094 desc = gpiochip_get_desc(chip, offset);
2096 return PTR_ERR(desc);
2098 /* Flush direction if something changed behind our back */
2099 if (chip->get_direction) {
2100 int dir = chip->get_direction(chip, offset);
2103 clear_bit(FLAG_IS_OUT, &desc->flags);
2105 set_bit(FLAG_IS_OUT, &desc->flags);
2108 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
2110 "%s: tried to flag a GPIO set as output for IRQ\n",
2115 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
2118 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
2121 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
2122 * @chip: the chip the GPIO to lock belongs to
2123 * @offset: the offset of the GPIO to lock as IRQ
2125 * This is used directly by GPIO drivers that want to indicate
2126 * that a certain GPIO is no longer used exclusively for IRQ.
2128 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
2130 if (offset >= chip->ngpio)
2133 clear_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2135 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
2137 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
2139 if (offset >= chip->ngpio)
2142 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2144 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
2146 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
2148 if (offset >= chip->ngpio)
2151 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
2153 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
2155 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
2157 if (offset >= chip->ngpio)
2160 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
2162 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
2165 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2166 * @desc: gpio whose value will be returned
2168 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2169 * its ACTIVE_LOW status, or negative errno on failure.
2171 * This function is to be called from contexts that can sleep.
2173 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
2175 might_sleep_if(extra_checks);
2176 VALIDATE_DESC(desc);
2177 return _gpiod_get_raw_value(desc);
2179 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
2182 * gpiod_get_value_cansleep() - return a gpio's value
2183 * @desc: gpio whose value will be returned
2185 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2186 * account, or negative errno on failure.
2188 * This function is to be called from contexts that can sleep.
2190 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
2194 might_sleep_if(extra_checks);
2195 VALIDATE_DESC(desc);
2196 value = _gpiod_get_raw_value(desc);
2200 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2205 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
2208 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2209 * @desc: gpio whose value will be assigned
2210 * @value: value to assign
2212 * Set the raw value of the GPIO, i.e. the value of its physical line without
2213 * regard for its ACTIVE_LOW status.
2215 * This function is to be called from contexts that can sleep.
2217 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
2219 might_sleep_if(extra_checks);
2220 VALIDATE_DESC_VOID(desc);
2221 _gpiod_set_raw_value(desc, value);
2223 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
2226 * gpiod_set_value_cansleep() - assign a gpio's value
2227 * @desc: gpio whose value will be assigned
2228 * @value: value to assign
2230 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2233 * This function is to be called from contexts that can sleep.
2235 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
2237 might_sleep_if(extra_checks);
2238 VALIDATE_DESC_VOID(desc);
2239 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2241 _gpiod_set_raw_value(desc, value);
2243 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
2246 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2247 * @array_size: number of elements in the descriptor / value arrays
2248 * @desc_array: array of GPIO descriptors whose values will be assigned
2249 * @value_array: array of values to assign
2251 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2252 * without regard for their ACTIVE_LOW status.
2254 * This function is to be called from contexts that can sleep.
2256 void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
2257 struct gpio_desc **desc_array,
2260 might_sleep_if(extra_checks);
2263 gpiod_set_array_value_complex(true, true, array_size, desc_array,
2266 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
2269 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2270 * @array_size: number of elements in the descriptor / value arrays
2271 * @desc_array: array of GPIO descriptors whose values will be assigned
2272 * @value_array: array of values to assign
2274 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2277 * This function is to be called from contexts that can sleep.
2279 void gpiod_set_array_value_cansleep(unsigned int array_size,
2280 struct gpio_desc **desc_array,
2283 might_sleep_if(extra_checks);
2286 gpiod_set_array_value_complex(false, true, array_size, desc_array,
2289 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
2292 * gpiod_add_lookup_table() - register GPIO device consumers
2293 * @table: table of consumers to register
2295 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
2297 mutex_lock(&gpio_lookup_lock);
2299 list_add_tail(&table->list, &gpio_lookup_list);
2301 mutex_unlock(&gpio_lookup_lock);
2305 * gpiod_remove_lookup_table() - unregister GPIO device consumers
2306 * @table: table of consumers to unregister
2308 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
2310 mutex_lock(&gpio_lookup_lock);
2312 list_del(&table->list);
2314 mutex_unlock(&gpio_lookup_lock);
2317 static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
2319 enum gpio_lookup_flags *flags)
2321 char prop_name[32]; /* 32 is max size of property name */
2322 enum of_gpio_flags of_flags;
2323 struct gpio_desc *desc;
2326 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
2328 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
2331 snprintf(prop_name, sizeof(prop_name), "%s",
2334 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
2336 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
2343 if (of_flags & OF_GPIO_ACTIVE_LOW)
2344 *flags |= GPIO_ACTIVE_LOW;
2346 if (of_flags & OF_GPIO_SINGLE_ENDED) {
2347 if (of_flags & OF_GPIO_ACTIVE_LOW)
2348 *flags |= GPIO_OPEN_DRAIN;
2350 *flags |= GPIO_OPEN_SOURCE;
2356 static struct gpio_desc *acpi_find_gpio(struct device *dev,
2359 enum gpiod_flags flags,
2360 enum gpio_lookup_flags *lookupflags)
2362 struct acpi_device *adev = ACPI_COMPANION(dev);
2363 struct acpi_gpio_info info;
2364 struct gpio_desc *desc;
2368 /* Try first from _DSD */
2369 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
2370 if (con_id && strcmp(con_id, "gpios")) {
2371 snprintf(propname, sizeof(propname), "%s-%s",
2372 con_id, gpio_suffixes[i]);
2374 snprintf(propname, sizeof(propname), "%s",
2378 desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
2379 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
2383 /* Then from plain _CRS GPIOs */
2385 if (!acpi_can_fallback_to_crs(adev, con_id))
2386 return ERR_PTR(-ENOENT);
2388 desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
2392 if ((flags == GPIOD_OUT_LOW || flags == GPIOD_OUT_HIGH) &&
2394 dev_dbg(dev, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n");
2395 return ERR_PTR(-ENOENT);
2399 if (info.polarity == GPIO_ACTIVE_LOW)
2400 *lookupflags |= GPIO_ACTIVE_LOW;
2405 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
2407 const char *dev_id = dev ? dev_name(dev) : NULL;
2408 struct gpiod_lookup_table *table;
2410 mutex_lock(&gpio_lookup_lock);
2412 list_for_each_entry(table, &gpio_lookup_list, list) {
2413 if (table->dev_id && dev_id) {
2415 * Valid strings on both ends, must be identical to have
2418 if (!strcmp(table->dev_id, dev_id))
2422 * One of the pointers is NULL, so both must be to have
2425 if (dev_id == table->dev_id)
2432 mutex_unlock(&gpio_lookup_lock);
2436 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
2438 enum gpio_lookup_flags *flags)
2440 struct gpio_desc *desc = ERR_PTR(-ENOENT);
2441 struct gpiod_lookup_table *table;
2442 struct gpiod_lookup *p;
2444 table = gpiod_find_lookup_table(dev);
2448 for (p = &table->table[0]; p->chip_label; p++) {
2449 struct gpio_chip *chip;
2451 /* idx must always match exactly */
2455 /* If the lookup entry has a con_id, require exact match */
2456 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
2459 chip = find_chip_by_name(p->chip_label);
2462 dev_err(dev, "cannot find GPIO chip %s\n",
2464 return ERR_PTR(-ENODEV);
2467 if (chip->ngpio <= p->chip_hwnum) {
2469 "requested GPIO %d is out of range [0..%d] for chip %s\n",
2470 idx, chip->ngpio, chip->label);
2471 return ERR_PTR(-EINVAL);
2474 desc = gpiochip_get_desc(chip, p->chip_hwnum);
2483 static int dt_gpio_count(struct device *dev, const char *con_id)
2489 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
2491 snprintf(propname, sizeof(propname), "%s-%s",
2492 con_id, gpio_suffixes[i]);
2494 snprintf(propname, sizeof(propname), "%s",
2497 ret = of_gpio_named_count(dev->of_node, propname);
2504 static int platform_gpio_count(struct device *dev, const char *con_id)
2506 struct gpiod_lookup_table *table;
2507 struct gpiod_lookup *p;
2508 unsigned int count = 0;
2510 table = gpiod_find_lookup_table(dev);
2514 for (p = &table->table[0]; p->chip_label; p++) {
2515 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
2516 (!con_id && !p->con_id))
2526 * gpiod_count - return the number of GPIOs associated with a device / function
2527 * or -ENOENT if no GPIO has been assigned to the requested function
2528 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2529 * @con_id: function within the GPIO consumer
2531 int gpiod_count(struct device *dev, const char *con_id)
2533 int count = -ENOENT;
2535 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
2536 count = dt_gpio_count(dev, con_id);
2537 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
2538 count = acpi_gpio_count(dev, con_id);
2541 count = platform_gpio_count(dev, con_id);
2545 EXPORT_SYMBOL_GPL(gpiod_count);
2548 * gpiod_get - obtain a GPIO for a given GPIO function
2549 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2550 * @con_id: function within the GPIO consumer
2551 * @flags: optional GPIO initialization flags
2553 * Return the GPIO descriptor corresponding to the function con_id of device
2554 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
2555 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
2557 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
2558 enum gpiod_flags flags)
2560 return gpiod_get_index(dev, con_id, 0, flags);
2562 EXPORT_SYMBOL_GPL(gpiod_get);
2565 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
2566 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2567 * @con_id: function within the GPIO consumer
2568 * @flags: optional GPIO initialization flags
2570 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
2571 * the requested function it will return NULL. This is convenient for drivers
2572 * that need to handle optional GPIOs.
2574 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
2576 enum gpiod_flags flags)
2578 return gpiod_get_index_optional(dev, con_id, 0, flags);
2580 EXPORT_SYMBOL_GPL(gpiod_get_optional);
2584 * gpiod_configure_flags - helper function to configure a given GPIO
2585 * @desc: gpio whose value will be assigned
2586 * @con_id: function within the GPIO consumer
2587 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2589 * @dflags: gpiod_flags - optional GPIO initialization flags
2591 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
2592 * requested function and/or index, or another IS_ERR() code if an error
2593 * occurred while trying to acquire the GPIO.
2595 static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
2596 unsigned long lflags, enum gpiod_flags dflags)
2600 if (lflags & GPIO_ACTIVE_LOW)
2601 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
2602 if (lflags & GPIO_OPEN_DRAIN)
2603 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
2604 if (lflags & GPIO_OPEN_SOURCE)
2605 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
2607 /* No particular flag request, return here... */
2608 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
2609 pr_debug("no flags found for %s\n", con_id);
2614 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
2615 status = gpiod_direction_output(desc,
2616 dflags & GPIOD_FLAGS_BIT_DIR_VAL);
2618 status = gpiod_direction_input(desc);
2624 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
2625 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2626 * @con_id: function within the GPIO consumer
2627 * @idx: index of the GPIO to obtain in the consumer
2628 * @flags: optional GPIO initialization flags
2630 * This variant of gpiod_get() allows to access GPIOs other than the first
2631 * defined one for functions that define several GPIOs.
2633 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
2634 * requested function and/or index, or another IS_ERR() code if an error
2635 * occurred while trying to acquire the GPIO.
2637 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
2640 enum gpiod_flags flags)
2642 struct gpio_desc *desc = NULL;
2644 enum gpio_lookup_flags lookupflags = 0;
2646 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
2649 /* Using device tree? */
2650 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
2651 dev_dbg(dev, "using device tree for GPIO lookup\n");
2652 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
2653 } else if (ACPI_COMPANION(dev)) {
2654 dev_dbg(dev, "using ACPI for GPIO lookup\n");
2655 desc = acpi_find_gpio(dev, con_id, idx, flags, &lookupflags);
2660 * Either we are not using DT or ACPI, or their lookup did not return
2661 * a result. In that case, use platform lookup as a fallback.
2663 if (!desc || desc == ERR_PTR(-ENOENT)) {
2664 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
2665 desc = gpiod_find(dev, con_id, idx, &lookupflags);
2669 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
2673 status = gpiod_request(desc, con_id);
2675 return ERR_PTR(status);
2677 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
2679 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
2681 return ERR_PTR(status);
2686 EXPORT_SYMBOL_GPL(gpiod_get_index);
2689 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
2690 * @fwnode: handle of the firmware node
2691 * @propname: name of the firmware property representing the GPIO
2693 * This function can be used for drivers that get their configuration
2696 * Function properly finds the corresponding GPIO using whatever is the
2697 * underlying firmware interface and then makes sure that the GPIO
2698 * descriptor is requested before it is returned to the caller.
2700 * In case of error an ERR_PTR() is returned.
2702 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
2703 const char *propname)
2705 struct gpio_desc *desc = ERR_PTR(-ENODEV);
2706 bool active_low = false;
2707 bool single_ended = false;
2711 return ERR_PTR(-EINVAL);
2713 if (is_of_node(fwnode)) {
2714 enum of_gpio_flags flags;
2716 desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0,
2718 if (!IS_ERR(desc)) {
2719 active_low = flags & OF_GPIO_ACTIVE_LOW;
2720 single_ended = flags & OF_GPIO_SINGLE_ENDED;
2722 } else if (is_acpi_node(fwnode)) {
2723 struct acpi_gpio_info info;
2725 desc = acpi_node_get_gpiod(fwnode, propname, 0, &info);
2727 active_low = info.polarity == GPIO_ACTIVE_LOW;
2733 ret = gpiod_request(desc, NULL);
2735 return ERR_PTR(ret);
2738 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
2742 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
2744 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
2749 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
2752 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
2754 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2755 * @con_id: function within the GPIO consumer
2756 * @index: index of the GPIO to obtain in the consumer
2757 * @flags: optional GPIO initialization flags
2759 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
2760 * specified index was assigned to the requested function it will return NULL.
2761 * This is convenient for drivers that need to handle optional GPIOs.
2763 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
2766 enum gpiod_flags flags)
2768 struct gpio_desc *desc;
2770 desc = gpiod_get_index(dev, con_id, index, flags);
2772 if (PTR_ERR(desc) == -ENOENT)
2778 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
2781 * gpiod_hog - Hog the specified GPIO desc given the provided flags
2782 * @desc: gpio whose value will be assigned
2783 * @name: gpio line name
2784 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2786 * @dflags: gpiod_flags - optional GPIO initialization flags
2788 int gpiod_hog(struct gpio_desc *desc, const char *name,
2789 unsigned long lflags, enum gpiod_flags dflags)
2791 struct gpio_chip *chip;
2792 struct gpio_desc *local_desc;
2796 chip = gpiod_to_chip(desc);
2797 hwnum = gpio_chip_hwgpio(desc);
2799 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
2800 if (IS_ERR(local_desc)) {
2801 status = PTR_ERR(local_desc);
2802 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
2803 name, chip->label, hwnum, status);
2807 status = gpiod_configure_flags(desc, name, lflags, dflags);
2809 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
2810 name, chip->label, hwnum, status);
2811 gpiochip_free_own_desc(desc);
2815 /* Mark GPIO as hogged so it can be identified and removed later */
2816 set_bit(FLAG_IS_HOGGED, &desc->flags);
2818 pr_info("GPIO line %d (%s) hogged as %s%s\n",
2819 desc_to_gpio(desc), name,
2820 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
2821 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
2822 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
2828 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
2829 * @chip: gpio chip to act on
2831 * This is only used by of_gpiochip_remove to free hogged gpios
2833 static void gpiochip_free_hogs(struct gpio_chip *chip)
2837 for (id = 0; id < chip->ngpio; id++) {
2838 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
2839 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
2844 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
2845 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2846 * @con_id: function within the GPIO consumer
2847 * @flags: optional GPIO initialization flags
2849 * This function acquires all the GPIOs defined under a given function.
2851 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
2852 * no GPIO has been assigned to the requested function, or another IS_ERR()
2853 * code if an error occurred while trying to acquire the GPIOs.
2855 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
2857 enum gpiod_flags flags)
2859 struct gpio_desc *desc;
2860 struct gpio_descs *descs;
2863 count = gpiod_count(dev, con_id);
2865 return ERR_PTR(count);
2867 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
2870 return ERR_PTR(-ENOMEM);
2872 for (descs->ndescs = 0; descs->ndescs < count; ) {
2873 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
2875 gpiod_put_array(descs);
2876 return ERR_CAST(desc);
2878 descs->desc[descs->ndescs] = desc;
2883 EXPORT_SYMBOL_GPL(gpiod_get_array);
2886 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
2888 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2889 * @con_id: function within the GPIO consumer
2890 * @flags: optional GPIO initialization flags
2892 * This is equivalent to gpiod_get_array(), except that when no GPIO was
2893 * assigned to the requested function it will return NULL.
2895 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
2897 enum gpiod_flags flags)
2899 struct gpio_descs *descs;
2901 descs = gpiod_get_array(dev, con_id, flags);
2902 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
2907 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
2910 * gpiod_put - dispose of a GPIO descriptor
2911 * @desc: GPIO descriptor to dispose of
2913 * No descriptor can be used after gpiod_put() has been called on it.
2915 void gpiod_put(struct gpio_desc *desc)
2919 EXPORT_SYMBOL_GPL(gpiod_put);
2922 * gpiod_put_array - dispose of multiple GPIO descriptors
2923 * @descs: struct gpio_descs containing an array of descriptors
2925 void gpiod_put_array(struct gpio_descs *descs)
2929 for (i = 0; i < descs->ndescs; i++)
2930 gpiod_put(descs->desc[i]);
2934 EXPORT_SYMBOL_GPL(gpiod_put_array);
2936 static int __init gpiolib_dev_init(void)
2940 /* Register GPIO sysfs bus */
2941 ret = bus_register(&gpio_bus_type);
2943 pr_err("gpiolib: could not register GPIO bus type\n");
2947 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
2949 pr_err("gpiolib: failed to allocate char dev region\n");
2950 bus_unregister(&gpio_bus_type);
2952 gpiolib_initialized = true;
2953 gpiochip_setup_devs();
2957 core_initcall(gpiolib_dev_init);
2959 #ifdef CONFIG_DEBUG_FS
2961 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
2964 struct gpio_chip *chip = gdev->chip;
2965 unsigned gpio = gdev->base;
2966 struct gpio_desc *gdesc = &gdev->descs[0];
2970 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
2971 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
2973 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
2979 gpiod_get_direction(gdesc);
2980 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
2981 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
2982 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
2983 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
2984 is_out ? "out" : "in ",
2986 ? (chip->get(chip, i) ? "hi" : "lo")
2988 is_irq ? "IRQ" : " ");
2989 seq_printf(s, "\n");
2993 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
2995 unsigned long flags;
2996 struct gpio_device *gdev = NULL;
2997 loff_t index = *pos;
3001 spin_lock_irqsave(&gpio_lock, flags);
3002 list_for_each_entry(gdev, &gpio_devices, list)
3004 spin_unlock_irqrestore(&gpio_lock, flags);
3007 spin_unlock_irqrestore(&gpio_lock, flags);
3012 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
3014 unsigned long flags;
3015 struct gpio_device *gdev = v;
3018 spin_lock_irqsave(&gpio_lock, flags);
3019 if (list_is_last(&gdev->list, &gpio_devices))
3022 ret = list_entry(gdev->list.next, struct gpio_device, list);
3023 spin_unlock_irqrestore(&gpio_lock, flags);
3031 static void gpiolib_seq_stop(struct seq_file *s, void *v)
3035 static int gpiolib_seq_show(struct seq_file *s, void *v)
3037 struct gpio_device *gdev = v;
3038 struct gpio_chip *chip = gdev->chip;
3039 struct device *parent;
3042 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
3043 dev_name(&gdev->dev));
3047 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
3048 dev_name(&gdev->dev),
3049 gdev->base, gdev->base + gdev->ngpio - 1);
3050 parent = chip->parent;
3052 seq_printf(s, ", parent: %s/%s",
3053 parent->bus ? parent->bus->name : "no-bus",
3056 seq_printf(s, ", %s", chip->label);
3057 if (chip->can_sleep)
3058 seq_printf(s, ", can sleep");
3059 seq_printf(s, ":\n");
3062 chip->dbg_show(s, chip);
3064 gpiolib_dbg_show(s, gdev);
3069 static const struct seq_operations gpiolib_seq_ops = {
3070 .start = gpiolib_seq_start,
3071 .next = gpiolib_seq_next,
3072 .stop = gpiolib_seq_stop,
3073 .show = gpiolib_seq_show,
3076 static int gpiolib_open(struct inode *inode, struct file *file)
3078 return seq_open(file, &gpiolib_seq_ops);
3081 static const struct file_operations gpiolib_operations = {
3082 .owner = THIS_MODULE,
3083 .open = gpiolib_open,
3085 .llseek = seq_lseek,
3086 .release = seq_release,
3089 static int __init gpiolib_debugfs_init(void)
3091 /* /sys/kernel/debug/gpio */
3092 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
3093 NULL, NULL, &gpiolib_operations);
3096 subsys_initcall(gpiolib_debugfs_init);
3098 #endif /* DEBUG_FS */