1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/bitmap.h>
3 #include <linux/kernel.h>
4 #include <linux/module.h>
5 #include <linux/interrupt.h>
7 #include <linux/spinlock.h>
8 #include <linux/list.h>
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/debugfs.h>
12 #include <linux/seq_file.h>
13 #include <linux/gpio.h>
14 #include <linux/of_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>
21 #include <linux/cdev.h>
23 #include <linux/uaccess.h>
24 #include <linux/compat.h>
25 #include <linux/anon_inodes.h>
26 #include <linux/file.h>
27 #include <linux/kfifo.h>
28 #include <linux/poll.h>
29 #include <linux/timekeeping.h>
30 #include <uapi/linux/gpio.h>
34 #define CREATE_TRACE_POINTS
35 #include <trace/events/gpio.h>
37 /* Implementation infrastructure for GPIO interfaces.
39 * The GPIO programming interface allows for inlining speed-critical
40 * get/set operations for common cases, so that access to SOC-integrated
41 * GPIOs can sometimes cost only an instruction or two per bit.
45 /* When debugging, extend minimal trust to callers and platform code.
46 * Also emit diagnostic messages that may help initial bringup, when
47 * board setup or driver bugs are most common.
49 * Otherwise, minimize overhead in what may be bitbanging codepaths.
52 #define extra_checks 1
54 #define extra_checks 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 struct bus_type gpio_bus_type = {
66 * Number of GPIOs to use for the fast path in set array
68 #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
70 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
71 * While any GPIO is requested, its gpio_chip is not removable;
72 * each GPIO's "requested" flag serves as a lock and refcount.
74 DEFINE_SPINLOCK(gpio_lock);
76 static DEFINE_MUTEX(gpio_lookup_lock);
77 static LIST_HEAD(gpio_lookup_list);
78 LIST_HEAD(gpio_devices);
80 static DEFINE_MUTEX(gpio_machine_hogs_mutex);
81 static LIST_HEAD(gpio_machine_hogs);
83 static void gpiochip_free_hogs(struct gpio_chip *chip);
84 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
85 struct lock_class_key *lock_key,
86 struct lock_class_key *request_key);
87 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
88 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
89 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
91 static bool gpiolib_initialized;
93 static inline void desc_set_label(struct gpio_desc *d, const char *label)
99 * gpio_to_desc - Convert a GPIO number to its descriptor
100 * @gpio: global GPIO number
103 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
104 * with the given number exists in the system.
106 struct gpio_desc *gpio_to_desc(unsigned gpio)
108 struct gpio_device *gdev;
111 spin_lock_irqsave(&gpio_lock, flags);
113 list_for_each_entry(gdev, &gpio_devices, list) {
114 if (gdev->base <= gpio &&
115 gdev->base + gdev->ngpio > gpio) {
116 spin_unlock_irqrestore(&gpio_lock, flags);
117 return &gdev->descs[gpio - gdev->base];
121 spin_unlock_irqrestore(&gpio_lock, flags);
123 if (!gpio_is_valid(gpio))
124 WARN(1, "invalid GPIO %d\n", gpio);
128 EXPORT_SYMBOL_GPL(gpio_to_desc);
131 * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
132 * hardware number for this chip
134 * @hwnum: hardware number of the GPIO for this chip
137 * A pointer to the GPIO descriptor or %ERR_PTR(-EINVAL) if no GPIO exists
138 * in the given chip for the specified hardware number.
140 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
143 struct gpio_device *gdev = chip->gpiodev;
145 if (hwnum >= gdev->ngpio)
146 return ERR_PTR(-EINVAL);
148 return &gdev->descs[hwnum];
152 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
153 * @desc: GPIO descriptor
155 * This should disappear in the future but is needed since we still
156 * use GPIO numbers for error messages and sysfs nodes.
159 * The global GPIO number for the GPIO specified by its descriptor.
161 int desc_to_gpio(const struct gpio_desc *desc)
163 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
165 EXPORT_SYMBOL_GPL(desc_to_gpio);
169 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
170 * @desc: descriptor to return the chip of
172 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
174 if (!desc || !desc->gdev)
176 return desc->gdev->chip;
178 EXPORT_SYMBOL_GPL(gpiod_to_chip);
180 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
181 static int gpiochip_find_base(int ngpio)
183 struct gpio_device *gdev;
184 int base = ARCH_NR_GPIOS - ngpio;
186 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
187 /* found a free space? */
188 if (gdev->base + gdev->ngpio <= base)
191 /* nope, check the space right before the chip */
192 base = gdev->base - ngpio;
195 if (gpio_is_valid(base)) {
196 pr_debug("%s: found new base at %d\n", __func__, base);
199 pr_err("%s: cannot find free range\n", __func__);
205 * gpiod_get_direction - return the current direction of a GPIO
206 * @desc: GPIO to get the direction of
208 * Returns 0 for output, 1 for input, or an error code in case of error.
210 * This function may sleep if gpiod_cansleep() is true.
212 int gpiod_get_direction(struct gpio_desc *desc)
214 struct gpio_chip *chip;
218 chip = gpiod_to_chip(desc);
219 offset = gpio_chip_hwgpio(desc);
221 if (!chip->get_direction)
224 status = chip->get_direction(chip, offset);
226 /* GPIOF_DIR_IN, or other positive */
228 clear_bit(FLAG_IS_OUT, &desc->flags);
232 set_bit(FLAG_IS_OUT, &desc->flags);
236 EXPORT_SYMBOL_GPL(gpiod_get_direction);
239 * Add a new chip to the global chips list, keeping the list of chips sorted
240 * by range(means [base, base + ngpio - 1]) order.
242 * Return -EBUSY if the new chip overlaps with some other chip's integer
245 static int gpiodev_add_to_list(struct gpio_device *gdev)
247 struct gpio_device *prev, *next;
249 if (list_empty(&gpio_devices)) {
250 /* initial entry in list */
251 list_add_tail(&gdev->list, &gpio_devices);
255 next = list_entry(gpio_devices.next, struct gpio_device, list);
256 if (gdev->base + gdev->ngpio <= next->base) {
257 /* add before first entry */
258 list_add(&gdev->list, &gpio_devices);
262 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
263 if (prev->base + prev->ngpio <= gdev->base) {
264 /* add behind last entry */
265 list_add_tail(&gdev->list, &gpio_devices);
269 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
270 /* at the end of the list */
271 if (&next->list == &gpio_devices)
274 /* add between prev and next */
275 if (prev->base + prev->ngpio <= gdev->base
276 && gdev->base + gdev->ngpio <= next->base) {
277 list_add(&gdev->list, &prev->list);
282 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
287 * Convert a GPIO name to its descriptor
289 static struct gpio_desc *gpio_name_to_desc(const char * const name)
291 struct gpio_device *gdev;
294 spin_lock_irqsave(&gpio_lock, flags);
296 list_for_each_entry(gdev, &gpio_devices, list) {
299 for (i = 0; i != gdev->ngpio; ++i) {
300 struct gpio_desc *desc = &gdev->descs[i];
302 if (!desc->name || !name)
305 if (!strcmp(desc->name, name)) {
306 spin_unlock_irqrestore(&gpio_lock, flags);
312 spin_unlock_irqrestore(&gpio_lock, flags);
318 * Takes the names from gc->names and checks if they are all unique. If they
319 * are, they are assigned to their gpio descriptors.
321 * Warning if one of the names is already used for a different GPIO.
323 static int gpiochip_set_desc_names(struct gpio_chip *gc)
325 struct gpio_device *gdev = gc->gpiodev;
331 /* First check all names if they are unique */
332 for (i = 0; i != gc->ngpio; ++i) {
333 struct gpio_desc *gpio;
335 gpio = gpio_name_to_desc(gc->names[i]);
338 "Detected name collision for GPIO name '%s'\n",
342 /* Then add all names to the GPIO descriptors */
343 for (i = 0; i != gc->ngpio; ++i)
344 gdev->descs[i].name = gc->names[i];
349 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *chip)
353 p = kmalloc_array(BITS_TO_LONGS(chip->ngpio), sizeof(*p), GFP_KERNEL);
357 /* Assume by default all GPIOs are valid */
358 bitmap_fill(p, chip->ngpio);
363 static int gpiochip_alloc_valid_mask(struct gpio_chip *gpiochip)
365 #ifdef CONFIG_OF_GPIO
367 struct device_node *np = gpiochip->of_node;
369 size = of_property_count_u32_elems(np, "gpio-reserved-ranges");
370 if (size > 0 && size % 2 == 0)
371 gpiochip->need_valid_mask = true;
374 if (!gpiochip->need_valid_mask)
377 gpiochip->valid_mask = gpiochip_allocate_mask(gpiochip);
378 if (!gpiochip->valid_mask)
384 static int gpiochip_init_valid_mask(struct gpio_chip *gpiochip)
386 if (gpiochip->init_valid_mask)
387 return gpiochip->init_valid_mask(gpiochip);
392 static void gpiochip_free_valid_mask(struct gpio_chip *gpiochip)
394 kfree(gpiochip->valid_mask);
395 gpiochip->valid_mask = NULL;
398 bool gpiochip_line_is_valid(const struct gpio_chip *gpiochip,
401 /* No mask means all valid */
402 if (likely(!gpiochip->valid_mask))
404 return test_bit(offset, gpiochip->valid_mask);
406 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
409 * GPIO line handle management
413 * struct linehandle_state - contains the state of a userspace handle
414 * @gdev: the GPIO device the handle pertains to
415 * @label: consumer label used to tag descriptors
416 * @descs: the GPIO descriptors held by this handle
417 * @numdescs: the number of descriptors held in the descs array
419 struct linehandle_state {
420 struct gpio_device *gdev;
422 struct gpio_desc *descs[GPIOHANDLES_MAX];
426 #define GPIOHANDLE_REQUEST_VALID_FLAGS \
427 (GPIOHANDLE_REQUEST_INPUT | \
428 GPIOHANDLE_REQUEST_OUTPUT | \
429 GPIOHANDLE_REQUEST_ACTIVE_LOW | \
430 GPIOHANDLE_REQUEST_OPEN_DRAIN | \
431 GPIOHANDLE_REQUEST_OPEN_SOURCE)
433 static long linehandle_ioctl(struct file *filep, unsigned int cmd,
436 struct linehandle_state *lh = filep->private_data;
437 void __user *ip = (void __user *)arg;
438 struct gpiohandle_data ghd;
439 DECLARE_BITMAP(vals, GPIOHANDLES_MAX);
442 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
443 /* NOTE: It's ok to read values of output lines. */
444 int ret = gpiod_get_array_value_complex(false,
453 memset(&ghd, 0, sizeof(ghd));
454 for (i = 0; i < lh->numdescs; i++)
455 ghd.values[i] = test_bit(i, vals);
457 if (copy_to_user(ip, &ghd, sizeof(ghd)))
461 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
463 * All line descriptors were created at once with the same
464 * flags so just check if the first one is really output.
466 if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags))
469 if (copy_from_user(&ghd, ip, sizeof(ghd)))
472 /* Clamp all values to [0,1] */
473 for (i = 0; i < lh->numdescs; i++)
474 __assign_bit(i, vals, ghd.values[i]);
476 /* Reuse the array setting function */
477 return gpiod_set_array_value_complex(false,
488 static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
491 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
495 static int linehandle_release(struct inode *inode, struct file *filep)
497 struct linehandle_state *lh = filep->private_data;
498 struct gpio_device *gdev = lh->gdev;
501 for (i = 0; i < lh->numdescs; i++)
502 gpiod_free(lh->descs[i]);
505 put_device(&gdev->dev);
509 static const struct file_operations linehandle_fileops = {
510 .release = linehandle_release,
511 .owner = THIS_MODULE,
512 .llseek = noop_llseek,
513 .unlocked_ioctl = linehandle_ioctl,
515 .compat_ioctl = linehandle_ioctl_compat,
519 static int linehandle_create(struct gpio_device *gdev, void __user *ip)
521 struct gpiohandle_request handlereq;
522 struct linehandle_state *lh;
524 int fd, i, count = 0, ret;
527 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
529 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
532 lflags = handlereq.flags;
534 /* Return an error if an unknown flag is set */
535 if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
539 * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
540 * the hardware actually supports enabling both at the same time the
541 * electrical result would be disastrous.
543 if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
544 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
547 /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
548 if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) &&
549 ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
550 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
553 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
557 get_device(&gdev->dev);
559 /* Make sure this is terminated */
560 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
561 if (strlen(handlereq.consumer_label)) {
562 lh->label = kstrdup(handlereq.consumer_label,
570 /* Request each GPIO */
571 for (i = 0; i < handlereq.lines; i++) {
572 u32 offset = handlereq.lineoffsets[i];
573 struct gpio_desc *desc;
575 if (offset >= gdev->ngpio) {
580 desc = &gdev->descs[offset];
581 ret = gpiod_request(desc, lh->label);
587 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
588 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
589 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
590 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
591 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
592 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
594 ret = gpiod_set_transitory(desc, false);
599 * Lines have to be requested explicitly for input
600 * or output, else the line will be treated "as is".
602 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
603 int val = !!handlereq.default_values[i];
605 ret = gpiod_direction_output(desc, val);
608 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
609 ret = gpiod_direction_input(desc);
613 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
616 /* Let i point at the last handle */
618 lh->numdescs = handlereq.lines;
620 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
626 file = anon_inode_getfile("gpio-linehandle",
629 O_RDONLY | O_CLOEXEC);
632 goto out_put_unused_fd;
636 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
638 * fput() will trigger the release() callback, so do not go onto
639 * the regular error cleanup path here.
646 fd_install(fd, file);
648 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
656 for (i = 0; i < count; i++)
657 gpiod_free(lh->descs[i]);
661 put_device(&gdev->dev);
666 * GPIO line event management
670 * struct lineevent_state - contains the state of a userspace event
671 * @gdev: the GPIO device the event pertains to
672 * @label: consumer label used to tag descriptors
673 * @desc: the GPIO descriptor held by this event
674 * @eflags: the event flags this line was requested with
675 * @irq: the interrupt that trigger in response to events on this GPIO
676 * @wait: wait queue that handles blocking reads of events
677 * @events: KFIFO for the GPIO events
678 * @read_lock: mutex lock to protect reads from colliding with adding
679 * new events to the FIFO
680 * @timestamp: cache for the timestamp storing it between hardirq
681 * and IRQ thread, used to bring the timestamp close to the actual
684 struct lineevent_state {
685 struct gpio_device *gdev;
687 struct gpio_desc *desc;
690 wait_queue_head_t wait;
691 DECLARE_KFIFO(events, struct gpioevent_data, 16);
692 struct mutex read_lock;
696 #define GPIOEVENT_REQUEST_VALID_FLAGS \
697 (GPIOEVENT_REQUEST_RISING_EDGE | \
698 GPIOEVENT_REQUEST_FALLING_EDGE)
700 static __poll_t lineevent_poll(struct file *filep,
701 struct poll_table_struct *wait)
703 struct lineevent_state *le = filep->private_data;
706 poll_wait(filep, &le->wait, wait);
708 if (!kfifo_is_empty(&le->events))
709 events = EPOLLIN | EPOLLRDNORM;
715 static ssize_t lineevent_read(struct file *filep,
720 struct lineevent_state *le = filep->private_data;
724 if (count < sizeof(struct gpioevent_data))
728 if (kfifo_is_empty(&le->events)) {
729 if (filep->f_flags & O_NONBLOCK)
732 ret = wait_event_interruptible(le->wait,
733 !kfifo_is_empty(&le->events));
738 if (mutex_lock_interruptible(&le->read_lock))
740 ret = kfifo_to_user(&le->events, buf, count, &copied);
741 mutex_unlock(&le->read_lock);
747 * If we couldn't read anything from the fifo (a different
748 * thread might have been faster) we either return -EAGAIN if
749 * the file descriptor is non-blocking, otherwise we go back to
750 * sleep and wait for more data to arrive.
752 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
755 } while (copied == 0);
760 static int lineevent_release(struct inode *inode, struct file *filep)
762 struct lineevent_state *le = filep->private_data;
763 struct gpio_device *gdev = le->gdev;
765 free_irq(le->irq, le);
766 gpiod_free(le->desc);
769 put_device(&gdev->dev);
773 static long lineevent_ioctl(struct file *filep, unsigned int cmd,
776 struct lineevent_state *le = filep->private_data;
777 void __user *ip = (void __user *)arg;
778 struct gpiohandle_data ghd;
781 * We can get the value for an event line but not set it,
782 * because it is input by definition.
784 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
787 memset(&ghd, 0, sizeof(ghd));
789 val = gpiod_get_value_cansleep(le->desc);
794 if (copy_to_user(ip, &ghd, sizeof(ghd)))
803 static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
806 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
810 static const struct file_operations lineevent_fileops = {
811 .release = lineevent_release,
812 .read = lineevent_read,
813 .poll = lineevent_poll,
814 .owner = THIS_MODULE,
815 .llseek = noop_llseek,
816 .unlocked_ioctl = lineevent_ioctl,
818 .compat_ioctl = lineevent_ioctl_compat,
822 static irqreturn_t lineevent_irq_thread(int irq, void *p)
824 struct lineevent_state *le = p;
825 struct gpioevent_data ge;
828 /* Do not leak kernel stack to userspace */
829 memset(&ge, 0, sizeof(ge));
831 ge.timestamp = le->timestamp;
833 if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
834 && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
835 int level = gpiod_get_value_cansleep(le->desc);
837 /* Emit low-to-high event */
838 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
840 /* Emit high-to-low event */
841 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
842 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
843 /* Emit low-to-high event */
844 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
845 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
846 /* Emit high-to-low event */
847 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
852 ret = kfifo_put(&le->events, ge);
854 wake_up_poll(&le->wait, EPOLLIN);
859 static irqreturn_t lineevent_irq_handler(int irq, void *p)
861 struct lineevent_state *le = p;
864 * Just store the timestamp in hardirq context so we get it as
865 * close in time as possible to the actual event.
867 le->timestamp = ktime_get_real_ns();
869 return IRQ_WAKE_THREAD;
872 static int lineevent_create(struct gpio_device *gdev, void __user *ip)
874 struct gpioevent_request eventreq;
875 struct lineevent_state *le;
876 struct gpio_desc *desc;
885 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
888 le = kzalloc(sizeof(*le), GFP_KERNEL);
892 get_device(&gdev->dev);
894 /* Make sure this is terminated */
895 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
896 if (strlen(eventreq.consumer_label)) {
897 le->label = kstrdup(eventreq.consumer_label,
905 offset = eventreq.lineoffset;
906 lflags = eventreq.handleflags;
907 eflags = eventreq.eventflags;
909 if (offset >= gdev->ngpio) {
914 /* Return an error if a unknown flag is set */
915 if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
916 (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
921 /* This is just wrong: we don't look for events on output lines */
922 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
927 desc = &gdev->descs[offset];
928 ret = gpiod_request(desc, le->label);
934 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
935 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
936 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
937 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
938 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
939 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
941 ret = gpiod_direction_input(desc);
945 le->irq = gpiod_to_irq(desc);
951 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
952 irqflags |= IRQF_TRIGGER_RISING;
953 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
954 irqflags |= IRQF_TRIGGER_FALLING;
955 irqflags |= IRQF_ONESHOT;
957 INIT_KFIFO(le->events);
958 init_waitqueue_head(&le->wait);
959 mutex_init(&le->read_lock);
961 /* Request a thread to read the events */
962 ret = request_threaded_irq(le->irq,
963 lineevent_irq_handler,
964 lineevent_irq_thread,
971 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
977 file = anon_inode_getfile("gpio-event",
980 O_RDONLY | O_CLOEXEC);
983 goto out_put_unused_fd;
987 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
989 * fput() will trigger the release() callback, so do not go onto
990 * the regular error cleanup path here.
997 fd_install(fd, file);
1004 free_irq(le->irq, le);
1006 gpiod_free(le->desc);
1011 put_device(&gdev->dev);
1016 * gpio_ioctl() - ioctl handler for the GPIO chardev
1018 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1020 struct gpio_device *gdev = filp->private_data;
1021 struct gpio_chip *chip = gdev->chip;
1022 void __user *ip = (void __user *)arg;
1024 /* We fail any subsequent ioctl():s when the chip is gone */
1028 /* Fill in the struct and pass to userspace */
1029 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
1030 struct gpiochip_info chipinfo;
1032 memset(&chipinfo, 0, sizeof(chipinfo));
1034 strncpy(chipinfo.name, dev_name(&gdev->dev),
1035 sizeof(chipinfo.name));
1036 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
1037 strncpy(chipinfo.label, gdev->label,
1038 sizeof(chipinfo.label));
1039 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
1040 chipinfo.lines = gdev->ngpio;
1041 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
1044 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
1045 struct gpioline_info lineinfo;
1046 struct gpio_desc *desc;
1048 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
1050 if (lineinfo.line_offset >= gdev->ngpio)
1053 desc = &gdev->descs[lineinfo.line_offset];
1055 strncpy(lineinfo.name, desc->name,
1056 sizeof(lineinfo.name));
1057 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
1059 lineinfo.name[0] = '\0';
1062 strncpy(lineinfo.consumer, desc->label,
1063 sizeof(lineinfo.consumer));
1064 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
1066 lineinfo.consumer[0] = '\0';
1070 * Userspace only need to know that the kernel is using
1071 * this GPIO so it can't use it.
1074 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
1075 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
1076 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
1077 test_bit(FLAG_EXPORT, &desc->flags) ||
1078 test_bit(FLAG_SYSFS, &desc->flags))
1079 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
1080 if (test_bit(FLAG_IS_OUT, &desc->flags))
1081 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
1082 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1083 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
1084 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1085 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
1086 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1087 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
1089 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
1092 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
1093 return linehandle_create(gdev, ip);
1094 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
1095 return lineevent_create(gdev, ip);
1100 #ifdef CONFIG_COMPAT
1101 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
1104 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
1109 * gpio_chrdev_open() - open the chardev for ioctl operations
1110 * @inode: inode for this chardev
1111 * @filp: file struct for storing private data
1112 * Returns 0 on success
1114 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
1116 struct gpio_device *gdev = container_of(inode->i_cdev,
1117 struct gpio_device, chrdev);
1119 /* Fail on open if the backing gpiochip is gone */
1122 get_device(&gdev->dev);
1123 filp->private_data = gdev;
1125 return nonseekable_open(inode, filp);
1129 * gpio_chrdev_release() - close chardev after ioctl operations
1130 * @inode: inode for this chardev
1131 * @filp: file struct for storing private data
1132 * Returns 0 on success
1134 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1136 struct gpio_device *gdev = container_of(inode->i_cdev,
1137 struct gpio_device, chrdev);
1139 put_device(&gdev->dev);
1144 static const struct file_operations gpio_fileops = {
1145 .release = gpio_chrdev_release,
1146 .open = gpio_chrdev_open,
1147 .owner = THIS_MODULE,
1148 .llseek = no_llseek,
1149 .unlocked_ioctl = gpio_ioctl,
1150 #ifdef CONFIG_COMPAT
1151 .compat_ioctl = gpio_ioctl_compat,
1155 static void gpiodevice_release(struct device *dev)
1157 struct gpio_device *gdev = dev_get_drvdata(dev);
1159 list_del(&gdev->list);
1160 ida_simple_remove(&gpio_ida, gdev->id);
1161 kfree_const(gdev->label);
1166 static int gpiochip_setup_dev(struct gpio_device *gdev)
1170 cdev_init(&gdev->chrdev, &gpio_fileops);
1171 gdev->chrdev.owner = THIS_MODULE;
1172 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1174 status = cdev_device_add(&gdev->chrdev, &gdev->dev);
1178 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1179 MAJOR(gpio_devt), gdev->id);
1181 status = gpiochip_sysfs_register(gdev);
1183 goto err_remove_device;
1185 /* From this point, the .release() function cleans up gpio_device */
1186 gdev->dev.release = gpiodevice_release;
1187 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1188 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1189 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1194 cdev_device_del(&gdev->chrdev, &gdev->dev);
1198 static void gpiochip_machine_hog(struct gpio_chip *chip, struct gpiod_hog *hog)
1200 struct gpio_desc *desc;
1203 desc = gpiochip_get_desc(chip, hog->chip_hwnum);
1205 pr_err("%s: unable to get GPIO desc: %ld\n",
1206 __func__, PTR_ERR(desc));
1210 if (test_bit(FLAG_IS_HOGGED, &desc->flags))
1213 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
1215 pr_err("%s: unable to hog GPIO line (%s:%u): %d\n",
1216 __func__, chip->label, hog->chip_hwnum, rv);
1219 static void machine_gpiochip_add(struct gpio_chip *chip)
1221 struct gpiod_hog *hog;
1223 mutex_lock(&gpio_machine_hogs_mutex);
1225 list_for_each_entry(hog, &gpio_machine_hogs, list) {
1226 if (!strcmp(chip->label, hog->chip_label))
1227 gpiochip_machine_hog(chip, hog);
1230 mutex_unlock(&gpio_machine_hogs_mutex);
1233 static void gpiochip_setup_devs(void)
1235 struct gpio_device *gdev;
1238 list_for_each_entry(gdev, &gpio_devices, list) {
1239 err = gpiochip_setup_dev(gdev);
1241 pr_err("%s: Failed to initialize gpio device (%d)\n",
1242 dev_name(&gdev->dev), err);
1246 int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
1247 struct lock_class_key *lock_key,
1248 struct lock_class_key *request_key)
1250 unsigned long flags;
1253 int base = chip->base;
1254 struct gpio_device *gdev;
1257 * First: allocate and populate the internal stat container, and
1258 * set up the struct device.
1260 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1263 gdev->dev.bus = &gpio_bus_type;
1265 chip->gpiodev = gdev;
1267 gdev->dev.parent = chip->parent;
1268 gdev->dev.of_node = chip->parent->of_node;
1271 #ifdef CONFIG_OF_GPIO
1272 /* If the gpiochip has an assigned OF node this takes precedence */
1274 gdev->dev.of_node = chip->of_node;
1276 chip->of_node = gdev->dev.of_node;
1279 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1284 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1285 device_initialize(&gdev->dev);
1286 dev_set_drvdata(&gdev->dev, gdev);
1287 if (chip->parent && chip->parent->driver)
1288 gdev->owner = chip->parent->driver->owner;
1289 else if (chip->owner)
1290 /* TODO: remove chip->owner */
1291 gdev->owner = chip->owner;
1293 gdev->owner = THIS_MODULE;
1295 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1301 if (chip->ngpio == 0) {
1302 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1304 goto err_free_descs;
1307 if (chip->ngpio > FASTPATH_NGPIO)
1308 chip_warn(chip, "line cnt %u is greater than fast path cnt %u\n",
1309 chip->ngpio, FASTPATH_NGPIO);
1311 gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
1314 goto err_free_descs;
1317 gdev->ngpio = chip->ngpio;
1320 spin_lock_irqsave(&gpio_lock, flags);
1323 * TODO: this allocates a Linux GPIO number base in the global
1324 * GPIO numberspace for this chip. In the long run we want to
1325 * get *rid* of this numberspace and use only descriptors, but
1326 * it may be a pipe dream. It will not happen before we get rid
1327 * of the sysfs interface anyways.
1330 base = gpiochip_find_base(chip->ngpio);
1333 spin_unlock_irqrestore(&gpio_lock, flags);
1334 goto err_free_label;
1337 * TODO: it should not be necessary to reflect the assigned
1338 * base outside of the GPIO subsystem. Go over drivers and
1339 * see if anyone makes use of this, else drop this and assign
1346 status = gpiodev_add_to_list(gdev);
1348 spin_unlock_irqrestore(&gpio_lock, flags);
1349 goto err_free_label;
1352 spin_unlock_irqrestore(&gpio_lock, flags);
1354 for (i = 0; i < chip->ngpio; i++)
1355 gdev->descs[i].gdev = gdev;
1357 #ifdef CONFIG_PINCTRL
1358 INIT_LIST_HEAD(&gdev->pin_ranges);
1361 status = gpiochip_set_desc_names(chip);
1363 goto err_remove_from_list;
1365 status = gpiochip_irqchip_init_valid_mask(chip);
1367 goto err_remove_from_list;
1369 status = gpiochip_alloc_valid_mask(chip);
1371 goto err_remove_irqchip_mask;
1373 status = gpiochip_add_irqchip(chip, lock_key, request_key);
1375 goto err_remove_chip;
1377 status = of_gpiochip_add(chip);
1379 goto err_remove_chip;
1381 status = gpiochip_init_valid_mask(chip);
1383 goto err_remove_chip;
1385 for (i = 0; i < chip->ngpio; i++) {
1386 struct gpio_desc *desc = &gdev->descs[i];
1388 if (chip->get_direction && gpiochip_line_is_valid(chip, i))
1389 desc->flags = !chip->get_direction(chip, i) ?
1390 (1 << FLAG_IS_OUT) : 0;
1392 desc->flags = !chip->direction_input ?
1393 (1 << FLAG_IS_OUT) : 0;
1396 acpi_gpiochip_add(chip);
1398 machine_gpiochip_add(chip);
1401 * By first adding the chardev, and then adding the device,
1402 * we get a device node entry in sysfs under
1403 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1404 * coldplug of device nodes and other udev business.
1405 * We can do this only if gpiolib has been initialized.
1406 * Otherwise, defer until later.
1408 if (gpiolib_initialized) {
1409 status = gpiochip_setup_dev(gdev);
1411 goto err_remove_chip;
1416 acpi_gpiochip_remove(chip);
1417 gpiochip_free_hogs(chip);
1418 of_gpiochip_remove(chip);
1419 gpiochip_free_valid_mask(chip);
1420 err_remove_irqchip_mask:
1421 gpiochip_irqchip_free_valid_mask(chip);
1422 err_remove_from_list:
1423 spin_lock_irqsave(&gpio_lock, flags);
1424 list_del(&gdev->list);
1425 spin_unlock_irqrestore(&gpio_lock, flags);
1427 kfree_const(gdev->label);
1431 ida_simple_remove(&gpio_ida, gdev->id);
1432 /* failures here can mean systems won't boot... */
1433 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1434 gdev->base, gdev->base + gdev->ngpio - 1,
1435 chip->label ? : "generic", status);
1439 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1442 * gpiochip_get_data() - get per-subdriver data for the chip
1446 * The per-subdriver data for the chip.
1448 void *gpiochip_get_data(struct gpio_chip *chip)
1450 return chip->gpiodev->data;
1452 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1455 * gpiochip_remove() - unregister a gpio_chip
1456 * @chip: the chip to unregister
1458 * A gpio_chip with any GPIOs still requested may not be removed.
1460 void gpiochip_remove(struct gpio_chip *chip)
1462 struct gpio_device *gdev = chip->gpiodev;
1463 struct gpio_desc *desc;
1464 unsigned long flags;
1466 bool requested = false;
1468 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1469 gpiochip_sysfs_unregister(gdev);
1470 gpiochip_free_hogs(chip);
1471 /* Numb the device, cancelling all outstanding operations */
1473 gpiochip_irqchip_remove(chip);
1474 acpi_gpiochip_remove(chip);
1475 gpiochip_remove_pin_ranges(chip);
1476 of_gpiochip_remove(chip);
1477 gpiochip_free_valid_mask(chip);
1479 * We accept no more calls into the driver from this point, so
1480 * NULL the driver data pointer
1484 spin_lock_irqsave(&gpio_lock, flags);
1485 for (i = 0; i < gdev->ngpio; i++) {
1486 desc = &gdev->descs[i];
1487 if (test_bit(FLAG_REQUESTED, &desc->flags))
1490 spin_unlock_irqrestore(&gpio_lock, flags);
1493 dev_crit(&gdev->dev,
1494 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1497 * The gpiochip side puts its use of the device to rest here:
1498 * if there are no userspace clients, the chardev and device will
1499 * be removed, else it will be dangling until the last user is
1502 cdev_device_del(&gdev->chrdev, &gdev->dev);
1503 put_device(&gdev->dev);
1505 EXPORT_SYMBOL_GPL(gpiochip_remove);
1507 static void devm_gpio_chip_release(struct device *dev, void *res)
1509 struct gpio_chip *chip = *(struct gpio_chip **)res;
1511 gpiochip_remove(chip);
1514 static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
1517 struct gpio_chip **r = res;
1529 * devm_gpiochip_add_data() - Resource manager gpiochip_add_data()
1530 * @dev: pointer to the device that gpio_chip belongs to.
1531 * @chip: the chip to register, with chip->base initialized
1532 * @data: driver-private data associated with this chip
1534 * Context: potentially before irqs will work
1536 * The gpio chip automatically be released when the device is unbound.
1539 * A negative errno if the chip can't be registered, such as because the
1540 * chip->base is invalid or already associated with a different chip.
1541 * Otherwise it returns zero as a success code.
1543 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1546 struct gpio_chip **ptr;
1549 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1554 ret = gpiochip_add_data(chip, data);
1561 devres_add(dev, ptr);
1565 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1568 * gpiochip_find() - iterator for locating a specific gpio_chip
1569 * @data: data to pass to match function
1570 * @match: Callback function to check gpio_chip
1572 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1573 * determined by a user supplied @match callback. The callback should return
1574 * 0 if the device doesn't match and non-zero if it does. If the callback is
1575 * non-zero, this function will return to the caller and not iterate over any
1578 struct gpio_chip *gpiochip_find(void *data,
1579 int (*match)(struct gpio_chip *chip,
1582 struct gpio_device *gdev;
1583 struct gpio_chip *chip = NULL;
1584 unsigned long flags;
1586 spin_lock_irqsave(&gpio_lock, flags);
1587 list_for_each_entry(gdev, &gpio_devices, list)
1588 if (gdev->chip && match(gdev->chip, data)) {
1593 spin_unlock_irqrestore(&gpio_lock, flags);
1597 EXPORT_SYMBOL_GPL(gpiochip_find);
1599 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1601 const char *name = data;
1603 return !strcmp(chip->label, name);
1606 static struct gpio_chip *find_chip_by_name(const char *name)
1608 return gpiochip_find((void *)name, gpiochip_match_name);
1611 #ifdef CONFIG_GPIOLIB_IRQCHIP
1614 * The following is irqchip helper code for gpiochips.
1617 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1619 if (!gpiochip->irq.need_valid_mask)
1622 gpiochip->irq.valid_mask = gpiochip_allocate_mask(gpiochip);
1623 if (!gpiochip->irq.valid_mask)
1629 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1631 kfree(gpiochip->irq.valid_mask);
1632 gpiochip->irq.valid_mask = NULL;
1635 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1636 unsigned int offset)
1638 if (!gpiochip_line_is_valid(gpiochip, offset))
1640 /* No mask means all valid */
1641 if (likely(!gpiochip->irq.valid_mask))
1643 return test_bit(offset, gpiochip->irq.valid_mask);
1645 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1648 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1649 * @gpiochip: the gpiochip to set the irqchip chain to
1650 * @parent_irq: the irq number corresponding to the parent IRQ for this
1652 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1653 * coming out of the gpiochip. If the interrupt is nested rather than
1654 * cascaded, pass NULL in this handler argument
1656 static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
1657 unsigned int parent_irq,
1658 irq_flow_handler_t parent_handler)
1660 if (!gpiochip->irq.domain) {
1661 chip_err(gpiochip, "called %s before setting up irqchip\n",
1666 if (parent_handler) {
1667 if (gpiochip->can_sleep) {
1669 "you cannot have chained interrupts on a chip that may sleep\n");
1673 * The parent irqchip is already using the chip_data for this
1674 * irqchip, so our callbacks simply use the handler_data.
1676 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1679 gpiochip->irq.parent_irq = parent_irq;
1680 gpiochip->irq.parents = &gpiochip->irq.parent_irq;
1681 gpiochip->irq.num_parents = 1;
1686 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1687 * @gpiochip: the gpiochip to set the irqchip chain to
1688 * @irqchip: the irqchip to chain to the gpiochip
1689 * @parent_irq: the irq number corresponding to the parent IRQ for this
1691 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1692 * coming out of the gpiochip.
1694 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1695 struct irq_chip *irqchip,
1696 unsigned int parent_irq,
1697 irq_flow_handler_t parent_handler)
1699 if (gpiochip->irq.threaded) {
1700 chip_err(gpiochip, "tried to chain a threaded gpiochip\n");
1704 gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, parent_handler);
1706 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1709 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1710 * @gpiochip: the gpiochip to set the irqchip nested handler to
1711 * @irqchip: the irqchip to nest to the gpiochip
1712 * @parent_irq: the irq number corresponding to the parent IRQ for this
1715 void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1716 struct irq_chip *irqchip,
1717 unsigned int parent_irq)
1719 gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, NULL);
1721 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1724 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1725 * @d: the irqdomain used by this irqchip
1726 * @irq: the global irq number used by this GPIO irqchip irq
1727 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1729 * This function will set up the mapping for a certain IRQ line on a
1730 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1731 * stored inside the gpiochip.
1733 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1734 irq_hw_number_t hwirq)
1736 struct gpio_chip *chip = d->host_data;
1739 if (!gpiochip_irqchip_irq_valid(chip, hwirq))
1742 irq_set_chip_data(irq, chip);
1744 * This lock class tells lockdep that GPIO irqs are in a different
1745 * category than their parents, so it won't report false recursion.
1747 irq_set_lockdep_class(irq, chip->irq.lock_key, chip->irq.request_key);
1748 irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
1749 /* Chips that use nested thread handlers have them marked */
1750 if (chip->irq.threaded)
1751 irq_set_nested_thread(irq, 1);
1752 irq_set_noprobe(irq);
1754 if (chip->irq.num_parents == 1)
1755 err = irq_set_parent(irq, chip->irq.parents[0]);
1756 else if (chip->irq.map)
1757 err = irq_set_parent(irq, chip->irq.map[hwirq]);
1763 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1764 * is passed as default type.
1766 if (chip->irq.default_type != IRQ_TYPE_NONE)
1767 irq_set_irq_type(irq, chip->irq.default_type);
1771 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1773 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1775 struct gpio_chip *chip = d->host_data;
1777 if (chip->irq.threaded)
1778 irq_set_nested_thread(irq, 0);
1779 irq_set_chip_and_handler(irq, NULL, NULL);
1780 irq_set_chip_data(irq, NULL);
1782 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1784 static const struct irq_domain_ops gpiochip_domain_ops = {
1785 .map = gpiochip_irq_map,
1786 .unmap = gpiochip_irq_unmap,
1787 /* Virtually all GPIO irqchips are twocell:ed */
1788 .xlate = irq_domain_xlate_twocell,
1791 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1793 if (!gpiochip_irqchip_irq_valid(chip, offset))
1796 return irq_create_mapping(chip->irq.domain, offset);
1799 static int gpiochip_irq_reqres(struct irq_data *d)
1801 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1803 return gpiochip_reqres_irq(chip, d->hwirq);
1806 static void gpiochip_irq_relres(struct irq_data *d)
1808 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1810 gpiochip_relres_irq(chip, d->hwirq);
1813 static void gpiochip_irq_enable(struct irq_data *d)
1815 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1817 gpiochip_enable_irq(chip, d->hwirq);
1818 if (chip->irq.irq_enable)
1819 chip->irq.irq_enable(d);
1821 chip->irq.chip->irq_unmask(d);
1824 static void gpiochip_irq_disable(struct irq_data *d)
1826 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1828 if (chip->irq.irq_disable)
1829 chip->irq.irq_disable(d);
1831 chip->irq.chip->irq_mask(d);
1832 gpiochip_disable_irq(chip, d->hwirq);
1835 static void gpiochip_set_irq_hooks(struct gpio_chip *gpiochip)
1837 struct irq_chip *irqchip = gpiochip->irq.chip;
1839 if (!irqchip->irq_request_resources &&
1840 !irqchip->irq_release_resources) {
1841 irqchip->irq_request_resources = gpiochip_irq_reqres;
1842 irqchip->irq_release_resources = gpiochip_irq_relres;
1844 if (WARN_ON(gpiochip->irq.irq_enable))
1846 /* Check if the irqchip already has this hook... */
1847 if (irqchip->irq_enable == gpiochip_irq_enable) {
1849 * ...and if so, give a gentle warning that this is bad
1853 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1856 gpiochip->irq.irq_enable = irqchip->irq_enable;
1857 gpiochip->irq.irq_disable = irqchip->irq_disable;
1858 irqchip->irq_enable = gpiochip_irq_enable;
1859 irqchip->irq_disable = gpiochip_irq_disable;
1863 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1864 * @gpiochip: the GPIO chip to add the IRQ chip to
1865 * @lock_key: lockdep class for IRQ lock
1866 * @request_key: lockdep class for IRQ request
1868 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
1869 struct lock_class_key *lock_key,
1870 struct lock_class_key *request_key)
1872 struct irq_chip *irqchip = gpiochip->irq.chip;
1873 const struct irq_domain_ops *ops;
1874 struct device_node *np;
1881 if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {
1882 chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n");
1886 np = gpiochip->gpiodev->dev.of_node;
1887 type = gpiochip->irq.default_type;
1890 * Specifying a default trigger is a terrible idea if DT or ACPI is
1891 * used to configure the interrupts, as you may end up with
1892 * conflicting triggers. Tell the user, and reset to NONE.
1894 if (WARN(np && type != IRQ_TYPE_NONE,
1895 "%s: Ignoring %u default trigger\n", np->full_name, type))
1896 type = IRQ_TYPE_NONE;
1898 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1899 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1900 "Ignoring %u default trigger\n", type);
1901 type = IRQ_TYPE_NONE;
1904 gpiochip->to_irq = gpiochip_to_irq;
1905 gpiochip->irq.default_type = type;
1906 gpiochip->irq.lock_key = lock_key;
1907 gpiochip->irq.request_key = request_key;
1909 if (gpiochip->irq.domain_ops)
1910 ops = gpiochip->irq.domain_ops;
1912 ops = &gpiochip_domain_ops;
1914 gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
1915 gpiochip->irq.first,
1917 if (!gpiochip->irq.domain)
1920 if (gpiochip->irq.parent_handler) {
1921 void *data = gpiochip->irq.parent_handler_data ?: gpiochip;
1923 for (i = 0; i < gpiochip->irq.num_parents; i++) {
1925 * The parent IRQ chip is already using the chip_data
1926 * for this IRQ chip, so our callbacks simply use the
1929 irq_set_chained_handler_and_data(gpiochip->irq.parents[i],
1930 gpiochip->irq.parent_handler,
1935 gpiochip_set_irq_hooks(gpiochip);
1937 acpi_gpiochip_request_interrupts(gpiochip);
1943 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1944 * @gpiochip: the gpiochip to remove the irqchip from
1946 * This is called only from gpiochip_remove()
1948 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1950 struct irq_chip *irqchip = gpiochip->irq.chip;
1951 unsigned int offset;
1953 acpi_gpiochip_free_interrupts(gpiochip);
1955 if (irqchip && gpiochip->irq.parent_handler) {
1956 struct gpio_irq_chip *irq = &gpiochip->irq;
1959 for (i = 0; i < irq->num_parents; i++)
1960 irq_set_chained_handler_and_data(irq->parents[i],
1964 /* Remove all IRQ mappings and delete the domain */
1965 if (gpiochip->irq.domain) {
1968 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1969 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1972 irq = irq_find_mapping(gpiochip->irq.domain, offset);
1973 irq_dispose_mapping(irq);
1976 irq_domain_remove(gpiochip->irq.domain);
1980 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
1981 irqchip->irq_request_resources = NULL;
1982 irqchip->irq_release_resources = NULL;
1984 if (irqchip->irq_enable == gpiochip_irq_enable) {
1985 irqchip->irq_enable = gpiochip->irq.irq_enable;
1986 irqchip->irq_disable = gpiochip->irq.irq_disable;
1989 gpiochip->irq.irq_enable = NULL;
1990 gpiochip->irq.irq_disable = NULL;
1991 gpiochip->irq.chip = NULL;
1993 gpiochip_irqchip_free_valid_mask(gpiochip);
1997 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
1998 * @gpiochip: the gpiochip to add the irqchip to
1999 * @irqchip: the irqchip to add to the gpiochip
2000 * @first_irq: if not dynamically assigned, the base (first) IRQ to
2001 * allocate gpiochip irqs from
2002 * @handler: the irq handler to use (often a predefined irq core function)
2003 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
2004 * to have the core avoid setting up any default type in the hardware.
2005 * @threaded: whether this irqchip uses a nested thread handler
2006 * @lock_key: lockdep class for IRQ lock
2007 * @request_key: lockdep class for IRQ request
2009 * This function closely associates a certain irqchip with a certain
2010 * gpiochip, providing an irq domain to translate the local IRQs to
2011 * global irqs in the gpiolib core, and making sure that the gpiochip
2012 * is passed as chip data to all related functions. Driver callbacks
2013 * need to use gpiochip_get_data() to get their local state containers back
2014 * from the gpiochip passed as chip data. An irqdomain will be stored
2015 * in the gpiochip that shall be used by the driver to handle IRQ number
2016 * translation. The gpiochip will need to be initialized and registered
2017 * before calling this function.
2019 * This function will handle two cell:ed simple IRQs and assumes all
2020 * the pins on the gpiochip can generate a unique IRQ. Everything else
2021 * need to be open coded.
2023 int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
2024 struct irq_chip *irqchip,
2025 unsigned int first_irq,
2026 irq_flow_handler_t handler,
2029 struct lock_class_key *lock_key,
2030 struct lock_class_key *request_key)
2032 struct device_node *of_node;
2034 if (!gpiochip || !irqchip)
2037 if (!gpiochip->parent) {
2038 pr_err("missing gpiochip .dev parent pointer\n");
2041 gpiochip->irq.threaded = threaded;
2042 of_node = gpiochip->parent->of_node;
2043 #ifdef CONFIG_OF_GPIO
2045 * If the gpiochip has an assigned OF node this takes precedence
2046 * FIXME: get rid of this and use gpiochip->parent->of_node
2049 if (gpiochip->of_node)
2050 of_node = gpiochip->of_node;
2053 * Specifying a default trigger is a terrible idea if DT or ACPI is
2054 * used to configure the interrupts, as you may end-up with
2055 * conflicting triggers. Tell the user, and reset to NONE.
2057 if (WARN(of_node && type != IRQ_TYPE_NONE,
2058 "%pOF: Ignoring %d default trigger\n", of_node, type))
2059 type = IRQ_TYPE_NONE;
2060 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
2061 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
2062 "Ignoring %d default trigger\n", type);
2063 type = IRQ_TYPE_NONE;
2066 gpiochip->irq.chip = irqchip;
2067 gpiochip->irq.handler = handler;
2068 gpiochip->irq.default_type = type;
2069 gpiochip->to_irq = gpiochip_to_irq;
2070 gpiochip->irq.lock_key = lock_key;
2071 gpiochip->irq.request_key = request_key;
2072 gpiochip->irq.domain = irq_domain_add_simple(of_node,
2073 gpiochip->ngpio, first_irq,
2074 &gpiochip_domain_ops, gpiochip);
2075 if (!gpiochip->irq.domain) {
2076 gpiochip->irq.chip = NULL;
2080 gpiochip_set_irq_hooks(gpiochip);
2082 acpi_gpiochip_request_interrupts(gpiochip);
2086 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
2088 #else /* CONFIG_GPIOLIB_IRQCHIP */
2090 static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
2091 struct lock_class_key *lock_key,
2092 struct lock_class_key *request_key)
2097 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
2098 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
2102 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
2105 #endif /* CONFIG_GPIOLIB_IRQCHIP */
2108 * gpiochip_generic_request() - request the gpio function for a pin
2109 * @chip: the gpiochip owning the GPIO
2110 * @offset: the offset of the GPIO to request for GPIO function
2112 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
2114 return pinctrl_gpio_request(chip->gpiodev->base + offset);
2116 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2119 * gpiochip_generic_free() - free the gpio function from a pin
2120 * @chip: the gpiochip to request the gpio function for
2121 * @offset: the offset of the GPIO to free from GPIO function
2123 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
2125 pinctrl_gpio_free(chip->gpiodev->base + offset);
2127 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2130 * gpiochip_generic_config() - apply configuration for a pin
2131 * @chip: the gpiochip owning the GPIO
2132 * @offset: the offset of the GPIO to apply the configuration
2133 * @config: the configuration to be applied
2135 int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
2136 unsigned long config)
2138 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
2140 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2142 #ifdef CONFIG_PINCTRL
2145 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2146 * @chip: the gpiochip to add the range for
2147 * @pctldev: the pin controller to map to
2148 * @gpio_offset: the start offset in the current gpio_chip number space
2149 * @pin_group: name of the pin group inside the pin controller
2151 * Calling this function directly from a DeviceTree-supported
2152 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2153 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2154 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2156 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
2157 struct pinctrl_dev *pctldev,
2158 unsigned int gpio_offset, const char *pin_group)
2160 struct gpio_pin_range *pin_range;
2161 struct gpio_device *gdev = chip->gpiodev;
2164 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2166 chip_err(chip, "failed to allocate pin ranges\n");
2170 /* Use local offset as range ID */
2171 pin_range->range.id = gpio_offset;
2172 pin_range->range.gc = chip;
2173 pin_range->range.name = chip->label;
2174 pin_range->range.base = gdev->base + gpio_offset;
2175 pin_range->pctldev = pctldev;
2177 ret = pinctrl_get_group_pins(pctldev, pin_group,
2178 &pin_range->range.pins,
2179 &pin_range->range.npins);
2185 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2187 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2188 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2189 pinctrl_dev_get_devname(pctldev), pin_group);
2191 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2195 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2198 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2199 * @chip: the gpiochip to add the range for
2200 * @pinctl_name: the dev_name() of the pin controller to map to
2201 * @gpio_offset: the start offset in the current gpio_chip number space
2202 * @pin_offset: the start offset in the pin controller number space
2203 * @npins: the number of pins from the offset of each pin space (GPIO and
2204 * pin controller) to accumulate in this range
2207 * 0 on success, or a negative error-code on failure.
2209 * Calling this function directly from a DeviceTree-supported
2210 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2211 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2212 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2214 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
2215 unsigned int gpio_offset, unsigned int pin_offset,
2218 struct gpio_pin_range *pin_range;
2219 struct gpio_device *gdev = chip->gpiodev;
2222 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2224 chip_err(chip, "failed to allocate pin ranges\n");
2228 /* Use local offset as range ID */
2229 pin_range->range.id = gpio_offset;
2230 pin_range->range.gc = chip;
2231 pin_range->range.name = chip->label;
2232 pin_range->range.base = gdev->base + gpio_offset;
2233 pin_range->range.pin_base = pin_offset;
2234 pin_range->range.npins = npins;
2235 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2237 if (IS_ERR(pin_range->pctldev)) {
2238 ret = PTR_ERR(pin_range->pctldev);
2239 chip_err(chip, "could not create pin range\n");
2243 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2244 gpio_offset, gpio_offset + npins - 1,
2246 pin_offset, pin_offset + npins - 1);
2248 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2252 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2255 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2256 * @chip: the chip to remove all the mappings for
2258 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
2260 struct gpio_pin_range *pin_range, *tmp;
2261 struct gpio_device *gdev = chip->gpiodev;
2263 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2264 list_del(&pin_range->node);
2265 pinctrl_remove_gpio_range(pin_range->pctldev,
2270 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2272 #endif /* CONFIG_PINCTRL */
2274 /* These "optional" allocation calls help prevent drivers from stomping
2275 * on each other, and help provide better diagnostics in debugfs.
2276 * They're called even less than the "set direction" calls.
2278 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2280 struct gpio_chip *chip = desc->gdev->chip;
2282 unsigned long flags;
2285 spin_lock_irqsave(&gpio_lock, flags);
2287 /* NOTE: gpio_request() can be called in early boot,
2288 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2291 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2292 desc_set_label(desc, label ? : "?");
2299 if (chip->request) {
2300 /* chip->request may sleep */
2301 spin_unlock_irqrestore(&gpio_lock, flags);
2302 offset = gpio_chip_hwgpio(desc);
2303 if (gpiochip_line_is_valid(chip, offset))
2304 status = chip->request(chip, offset);
2307 spin_lock_irqsave(&gpio_lock, flags);
2310 desc_set_label(desc, NULL);
2311 clear_bit(FLAG_REQUESTED, &desc->flags);
2315 if (chip->get_direction) {
2316 /* chip->get_direction may sleep */
2317 spin_unlock_irqrestore(&gpio_lock, flags);
2318 gpiod_get_direction(desc);
2319 spin_lock_irqsave(&gpio_lock, flags);
2322 spin_unlock_irqrestore(&gpio_lock, flags);
2327 * This descriptor validation needs to be inserted verbatim into each
2328 * function taking a descriptor, so we need to use a preprocessor
2329 * macro to avoid endless duplication. If the desc is NULL it is an
2330 * optional GPIO and calls should just bail out.
2332 static int validate_desc(const struct gpio_desc *desc, const char *func)
2337 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2338 return PTR_ERR(desc);
2341 pr_warn("%s: invalid GPIO (no device)\n", func);
2344 if (!desc->gdev->chip) {
2345 dev_warn(&desc->gdev->dev,
2346 "%s: backing chip is gone\n", func);
2352 #define VALIDATE_DESC(desc) do { \
2353 int __valid = validate_desc(desc, __func__); \
2358 #define VALIDATE_DESC_VOID(desc) do { \
2359 int __valid = validate_desc(desc, __func__); \
2364 int gpiod_request(struct gpio_desc *desc, const char *label)
2366 int status = -EPROBE_DEFER;
2367 struct gpio_device *gdev;
2369 VALIDATE_DESC(desc);
2372 if (try_module_get(gdev->owner)) {
2373 status = gpiod_request_commit(desc, label);
2375 module_put(gdev->owner);
2377 get_device(&gdev->dev);
2381 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2386 static bool gpiod_free_commit(struct gpio_desc *desc)
2389 unsigned long flags;
2390 struct gpio_chip *chip;
2394 gpiod_unexport(desc);
2396 spin_lock_irqsave(&gpio_lock, flags);
2398 chip = desc->gdev->chip;
2399 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2401 spin_unlock_irqrestore(&gpio_lock, flags);
2402 might_sleep_if(chip->can_sleep);
2403 chip->free(chip, gpio_chip_hwgpio(desc));
2404 spin_lock_irqsave(&gpio_lock, flags);
2406 desc_set_label(desc, NULL);
2407 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2408 clear_bit(FLAG_REQUESTED, &desc->flags);
2409 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2410 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2411 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2415 spin_unlock_irqrestore(&gpio_lock, flags);
2419 void gpiod_free(struct gpio_desc *desc)
2421 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2422 module_put(desc->gdev->owner);
2423 put_device(&desc->gdev->dev);
2425 WARN_ON(extra_checks);
2430 * gpiochip_is_requested - return string iff signal was requested
2431 * @chip: controller managing the signal
2432 * @offset: of signal within controller's 0..(ngpio - 1) range
2434 * Returns NULL if the GPIO is not currently requested, else a string.
2435 * The string returned is the label passed to gpio_request(); if none has been
2436 * passed it is a meaningless, non-NULL constant.
2438 * This function is for use by GPIO controller drivers. The label can
2439 * help with diagnostics, and knowing that the signal is used as a GPIO
2440 * can help avoid accidentally multiplexing it to another controller.
2442 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2444 struct gpio_desc *desc;
2446 if (offset >= chip->ngpio)
2449 desc = &chip->gpiodev->descs[offset];
2451 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2455 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2458 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2460 * @hwnum: hardware number of the GPIO for which to request the descriptor
2461 * @label: label for the GPIO
2463 * Function allows GPIO chip drivers to request and use their own GPIO
2464 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2465 * function will not increase reference count of the GPIO chip module. This
2466 * allows the GPIO chip module to be unloaded as needed (we assume that the
2467 * GPIO chip driver handles freeing the GPIOs it has requested).
2470 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2473 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2476 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2480 chip_err(chip, "failed to get GPIO descriptor\n");
2484 err = gpiod_request_commit(desc, label);
2486 return ERR_PTR(err);
2490 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2493 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2494 * @desc: GPIO descriptor to free
2496 * Function frees the given GPIO requested previously with
2497 * gpiochip_request_own_desc().
2499 void gpiochip_free_own_desc(struct gpio_desc *desc)
2502 gpiod_free_commit(desc);
2504 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2507 * Drivers MUST set GPIO direction before making get/set calls. In
2508 * some cases this is done in early boot, before IRQs are enabled.
2510 * As a rule these aren't called more than once (except for drivers
2511 * using the open-drain emulation idiom) so these are natural places
2512 * to accumulate extra debugging checks. Note that we can't (yet)
2513 * rely on gpio_request() having been called beforehand.
2517 * gpiod_direction_input - set the GPIO direction to input
2518 * @desc: GPIO to set to input
2520 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2521 * be called safely on it.
2523 * Return 0 in case of success, else an error code.
2525 int gpiod_direction_input(struct gpio_desc *desc)
2527 struct gpio_chip *chip;
2530 VALIDATE_DESC(desc);
2531 chip = desc->gdev->chip;
2534 * It is legal to have no .get() and .direction_input() specified if
2535 * the chip is output-only, but you can't specify .direction_input()
2536 * and not support the .get() operation, that doesn't make sense.
2538 if (!chip->get && chip->direction_input) {
2540 "%s: missing get() but have direction_input()\n",
2546 * If we have a .direction_input() callback, things are simple,
2547 * just call it. Else we are some input-only chip so try to check the
2548 * direction (if .get_direction() is supported) else we silently
2549 * assume we are in input mode after this.
2551 if (chip->direction_input) {
2552 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2553 } else if (chip->get_direction &&
2554 (chip->get_direction(chip, gpio_chip_hwgpio(desc)) != 1)) {
2556 "%s: missing direction_input() operation and line is output\n",
2561 clear_bit(FLAG_IS_OUT, &desc->flags);
2563 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2567 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2569 static int gpio_set_drive_single_ended(struct gpio_chip *gc, unsigned offset,
2570 enum pin_config_param mode)
2572 unsigned long config = { PIN_CONF_PACKED(mode, 0) };
2574 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2577 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2579 struct gpio_chip *gc = desc->gdev->chip;
2584 * It's OK not to specify .direction_output() if the gpiochip is
2585 * output-only, but if there is then not even a .set() operation it
2586 * is pretty tricky to drive the output line.
2588 if (!gc->set && !gc->direction_output) {
2590 "%s: missing set() and direction_output() operations\n",
2595 if (gc->direction_output) {
2596 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2598 /* Check that we are in output mode if we can */
2599 if (gc->get_direction &&
2600 gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
2602 "%s: missing direction_output() operation\n",
2607 * If we can't actively set the direction, we are some
2608 * output-only chip, so just drive the output as desired.
2610 gc->set(gc, gpio_chip_hwgpio(desc), val);
2614 set_bit(FLAG_IS_OUT, &desc->flags);
2615 trace_gpio_value(desc_to_gpio(desc), 0, val);
2616 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2621 * gpiod_direction_output_raw - set the GPIO direction to output
2622 * @desc: GPIO to set to output
2623 * @value: initial output value of the GPIO
2625 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2626 * be called safely on it. The initial value of the output must be specified
2627 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2629 * Return 0 in case of success, else an error code.
2631 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2633 VALIDATE_DESC(desc);
2634 return gpiod_direction_output_raw_commit(desc, value);
2636 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2639 * gpiod_direction_output - set the GPIO direction to output
2640 * @desc: GPIO to set to output
2641 * @value: initial output value of the GPIO
2643 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2644 * be called safely on it. The initial value of the output must be specified
2645 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2648 * Return 0 in case of success, else an error code.
2650 int gpiod_direction_output(struct gpio_desc *desc, int value)
2652 struct gpio_chip *gc;
2655 VALIDATE_DESC(desc);
2656 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2661 /* GPIOs used for enabled IRQs shall not be set as output */
2662 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
2663 test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
2665 "%s: tried to set a GPIO tied to an IRQ as output\n",
2670 gc = desc->gdev->chip;
2671 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2672 /* First see if we can enable open drain in hardware */
2673 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2674 PIN_CONFIG_DRIVE_OPEN_DRAIN);
2676 goto set_output_value;
2677 /* Emulate open drain by not actively driving the line high */
2679 return gpiod_direction_input(desc);
2681 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2682 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2683 PIN_CONFIG_DRIVE_OPEN_SOURCE);
2685 goto set_output_value;
2686 /* Emulate open source by not actively driving the line low */
2688 return gpiod_direction_input(desc);
2690 gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2691 PIN_CONFIG_DRIVE_PUSH_PULL);
2695 return gpiod_direction_output_raw_commit(desc, value);
2697 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2700 * gpiod_set_debounce - sets @debounce time for a GPIO
2701 * @desc: descriptor of the GPIO for which to set debounce time
2702 * @debounce: debounce time in microseconds
2705 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2708 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2710 struct gpio_chip *chip;
2711 unsigned long config;
2713 VALIDATE_DESC(desc);
2714 chip = desc->gdev->chip;
2715 if (!chip->set || !chip->set_config) {
2717 "%s: missing set() or set_config() operations\n",
2722 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2723 return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
2725 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2728 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2729 * @desc: descriptor of the GPIO for which to configure persistence
2730 * @transitory: True to lose state on suspend or reset, false for persistence
2733 * 0 on success, otherwise a negative error code.
2735 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2737 struct gpio_chip *chip;
2738 unsigned long packed;
2742 VALIDATE_DESC(desc);
2744 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2745 * persistence state.
2748 set_bit(FLAG_TRANSITORY, &desc->flags);
2750 clear_bit(FLAG_TRANSITORY, &desc->flags);
2752 /* If the driver supports it, set the persistence state now */
2753 chip = desc->gdev->chip;
2754 if (!chip->set_config)
2757 packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
2759 gpio = gpio_chip_hwgpio(desc);
2760 rc = chip->set_config(chip, gpio, packed);
2761 if (rc == -ENOTSUPP) {
2762 dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
2769 EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2772 * gpiod_is_active_low - test whether a GPIO is active-low or not
2773 * @desc: the gpio descriptor to test
2775 * Returns 1 if the GPIO is active-low, 0 otherwise.
2777 int gpiod_is_active_low(const struct gpio_desc *desc)
2779 VALIDATE_DESC(desc);
2780 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2782 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2784 /* I/O calls are only valid after configuration completed; the relevant
2785 * "is this a valid GPIO" error checks should already have been done.
2787 * "Get" operations are often inlinable as reading a pin value register,
2788 * and masking the relevant bit in that register.
2790 * When "set" operations are inlinable, they involve writing that mask to
2791 * one register to set a low value, or a different register to set it high.
2792 * Otherwise locking is needed, so there may be little value to inlining.
2794 *------------------------------------------------------------------------
2796 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2797 * have requested the GPIO. That can include implicit requesting by
2798 * a direction setting call. Marking a gpio as requested locks its chip
2799 * in memory, guaranteeing that these table lookups need no more locking
2800 * and that gpiochip_remove() will fail.
2802 * REVISIT when debugging, consider adding some instrumentation to ensure
2803 * that the GPIO was actually requested.
2806 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2808 struct gpio_chip *chip;
2812 chip = desc->gdev->chip;
2813 offset = gpio_chip_hwgpio(desc);
2814 value = chip->get ? chip->get(chip, offset) : -EIO;
2815 value = value < 0 ? value : !!value;
2816 trace_gpio_value(desc_to_gpio(desc), 1, value);
2820 static int gpio_chip_get_multiple(struct gpio_chip *chip,
2821 unsigned long *mask, unsigned long *bits)
2823 if (chip->get_multiple) {
2824 return chip->get_multiple(chip, mask, bits);
2825 } else if (chip->get) {
2828 for_each_set_bit(i, mask, chip->ngpio) {
2829 value = chip->get(chip, i);
2832 __assign_bit(i, bits, value);
2839 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2840 unsigned int array_size,
2841 struct gpio_desc **desc_array,
2842 struct gpio_array *array_info,
2843 unsigned long *value_bitmap)
2848 * Validate array_info against desc_array and its size.
2849 * It should immediately follow desc_array if both
2850 * have been obtained from the same gpiod_get_array() call.
2852 if (array_info && array_info->desc == desc_array &&
2853 array_size <= array_info->size &&
2854 (void *)array_info == desc_array + array_info->size) {
2856 WARN_ON(array_info->chip->can_sleep);
2858 err = gpio_chip_get_multiple(array_info->chip,
2859 array_info->get_mask,
2864 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2865 bitmap_xor(value_bitmap, value_bitmap,
2866 array_info->invert_mask, array_size);
2868 if (bitmap_full(array_info->get_mask, array_size))
2871 i = find_first_zero_bit(array_info->get_mask, array_size);
2876 while (i < array_size) {
2877 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2878 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
2879 unsigned long *mask, *bits;
2882 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
2885 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
2887 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
2892 bits = mask + BITS_TO_LONGS(chip->ngpio);
2893 bitmap_zero(mask, chip->ngpio);
2896 WARN_ON(chip->can_sleep);
2898 /* collect all inputs belonging to the same chip */
2901 const struct gpio_desc *desc = desc_array[i];
2902 int hwgpio = gpio_chip_hwgpio(desc);
2904 __set_bit(hwgpio, mask);
2908 i = find_next_zero_bit(array_info->get_mask,
2910 } while ((i < array_size) &&
2911 (desc_array[i]->gdev->chip == chip));
2913 ret = gpio_chip_get_multiple(chip, mask, bits);
2915 if (mask != fastpath)
2920 for (j = first; j < i; ) {
2921 const struct gpio_desc *desc = desc_array[j];
2922 int hwgpio = gpio_chip_hwgpio(desc);
2923 int value = test_bit(hwgpio, bits);
2925 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2927 __assign_bit(j, value_bitmap, value);
2928 trace_gpio_value(desc_to_gpio(desc), 1, value);
2932 j = find_next_zero_bit(array_info->get_mask, i,
2936 if (mask != fastpath)
2943 * gpiod_get_raw_value() - return a gpio's raw value
2944 * @desc: gpio whose value will be returned
2946 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2947 * its ACTIVE_LOW status, or negative errno on failure.
2949 * This function should be called from contexts where we cannot sleep, and will
2950 * complain if the GPIO chip functions potentially sleep.
2952 int gpiod_get_raw_value(const struct gpio_desc *desc)
2954 VALIDATE_DESC(desc);
2955 /* Should be using gpio_get_value_cansleep() */
2956 WARN_ON(desc->gdev->chip->can_sleep);
2957 return gpiod_get_raw_value_commit(desc);
2959 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2962 * gpiod_get_value() - return a gpio's value
2963 * @desc: gpio whose value will be returned
2965 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2966 * account, or negative errno on failure.
2968 * This function should be called from contexts where we cannot sleep, and will
2969 * complain if the GPIO chip functions potentially sleep.
2971 int gpiod_get_value(const struct gpio_desc *desc)
2975 VALIDATE_DESC(desc);
2976 /* Should be using gpio_get_value_cansleep() */
2977 WARN_ON(desc->gdev->chip->can_sleep);
2979 value = gpiod_get_raw_value_commit(desc);
2983 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2988 EXPORT_SYMBOL_GPL(gpiod_get_value);
2991 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
2992 * @array_size: number of elements in the descriptor array / value bitmap
2993 * @desc_array: array of GPIO descriptors whose values will be read
2994 * @array_info: information on applicability of fast bitmap processing path
2995 * @value_bitmap: bitmap to store the read values
2997 * Read the raw values of the GPIOs, i.e. the values of the physical lines
2998 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
2999 * else an error code.
3001 * This function should be called from contexts where we cannot sleep,
3002 * and it will complain if the GPIO chip functions potentially sleep.
3004 int gpiod_get_raw_array_value(unsigned int array_size,
3005 struct gpio_desc **desc_array,
3006 struct gpio_array *array_info,
3007 unsigned long *value_bitmap)
3011 return gpiod_get_array_value_complex(true, false, array_size,
3012 desc_array, array_info,
3015 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
3018 * gpiod_get_array_value() - read values from an array of GPIOs
3019 * @array_size: number of elements in the descriptor array / value bitmap
3020 * @desc_array: array of GPIO descriptors whose values will be read
3021 * @array_info: information on applicability of fast bitmap processing path
3022 * @value_bitmap: bitmap to store the read values
3024 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3025 * into account. Return 0 in case of success, else an error code.
3027 * This function should be called from contexts where we cannot sleep,
3028 * and it will complain if the GPIO chip functions potentially sleep.
3030 int gpiod_get_array_value(unsigned int array_size,
3031 struct gpio_desc **desc_array,
3032 struct gpio_array *array_info,
3033 unsigned long *value_bitmap)
3037 return gpiod_get_array_value_complex(false, false, array_size,
3038 desc_array, array_info,
3041 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
3044 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
3045 * @desc: gpio descriptor whose state need to be set.
3046 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3048 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
3051 struct gpio_chip *chip = desc->gdev->chip;
3052 int offset = gpio_chip_hwgpio(desc);
3055 err = chip->direction_input(chip, offset);
3057 clear_bit(FLAG_IS_OUT, &desc->flags);
3059 err = chip->direction_output(chip, offset, 0);
3061 set_bit(FLAG_IS_OUT, &desc->flags);
3063 trace_gpio_direction(desc_to_gpio(desc), value, err);
3066 "%s: Error in set_value for open drain err %d\n",
3071 * _gpio_set_open_source_value() - Set the open source gpio's value.
3072 * @desc: gpio descriptor whose state need to be set.
3073 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3075 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
3078 struct gpio_chip *chip = desc->gdev->chip;
3079 int offset = gpio_chip_hwgpio(desc);
3082 err = chip->direction_output(chip, offset, 1);
3084 set_bit(FLAG_IS_OUT, &desc->flags);
3086 err = chip->direction_input(chip, offset);
3088 clear_bit(FLAG_IS_OUT, &desc->flags);
3090 trace_gpio_direction(desc_to_gpio(desc), !value, err);
3093 "%s: Error in set_value for open source err %d\n",
3097 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
3099 struct gpio_chip *chip;
3101 chip = desc->gdev->chip;
3102 trace_gpio_value(desc_to_gpio(desc), 0, value);
3103 chip->set(chip, gpio_chip_hwgpio(desc), value);
3107 * set multiple outputs on the same chip;
3108 * use the chip's set_multiple function if available;
3109 * otherwise set the outputs sequentially;
3110 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3111 * defines which outputs are to be changed
3112 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3113 * defines the values the outputs specified by mask are to be set to
3115 static void gpio_chip_set_multiple(struct gpio_chip *chip,
3116 unsigned long *mask, unsigned long *bits)
3118 if (chip->set_multiple) {
3119 chip->set_multiple(chip, mask, bits);
3123 /* set outputs if the corresponding mask bit is set */
3124 for_each_set_bit(i, mask, chip->ngpio)
3125 chip->set(chip, i, test_bit(i, bits));
3129 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3130 unsigned int array_size,
3131 struct gpio_desc **desc_array,
3132 struct gpio_array *array_info,
3133 unsigned long *value_bitmap)
3138 * Validate array_info against desc_array and its size.
3139 * It should immediately follow desc_array if both
3140 * have been obtained from the same gpiod_get_array() call.
3142 if (array_info && array_info->desc == desc_array &&
3143 array_size <= array_info->size &&
3144 (void *)array_info == desc_array + array_info->size) {
3146 WARN_ON(array_info->chip->can_sleep);
3148 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3149 bitmap_xor(value_bitmap, value_bitmap,
3150 array_info->invert_mask, array_size);
3152 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
3155 if (bitmap_full(array_info->set_mask, array_size))
3158 i = find_first_zero_bit(array_info->set_mask, array_size);
3163 while (i < array_size) {
3164 struct gpio_chip *chip = desc_array[i]->gdev->chip;
3165 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
3166 unsigned long *mask, *bits;
3169 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
3172 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
3174 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
3179 bits = mask + BITS_TO_LONGS(chip->ngpio);
3180 bitmap_zero(mask, chip->ngpio);
3183 WARN_ON(chip->can_sleep);
3186 struct gpio_desc *desc = desc_array[i];
3187 int hwgpio = gpio_chip_hwgpio(desc);
3188 int value = test_bit(i, value_bitmap);
3191 * Pins applicable for fast input but not for
3192 * fast output processing may have been already
3193 * inverted inside the fast path, skip them.
3195 if (!raw && !(array_info &&
3196 test_bit(i, array_info->invert_mask)) &&
3197 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3199 trace_gpio_value(desc_to_gpio(desc), 0, value);
3201 * collect all normal outputs belonging to the same chip
3202 * open drain and open source outputs are set individually
3204 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3205 gpio_set_open_drain_value_commit(desc, value);
3206 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3207 gpio_set_open_source_value_commit(desc, value);
3209 __set_bit(hwgpio, mask);
3211 __set_bit(hwgpio, bits);
3213 __clear_bit(hwgpio, bits);
3219 i = find_next_zero_bit(array_info->set_mask,
3221 } while ((i < array_size) &&
3222 (desc_array[i]->gdev->chip == chip));
3223 /* push collected bits to outputs */
3225 gpio_chip_set_multiple(chip, mask, bits);
3227 if (mask != fastpath)
3234 * gpiod_set_raw_value() - assign a gpio's raw value
3235 * @desc: gpio whose value will be assigned
3236 * @value: value to assign
3238 * Set the raw value of the GPIO, i.e. the value of its physical line without
3239 * regard for its ACTIVE_LOW status.
3241 * This function should be called from contexts where we cannot sleep, and will
3242 * complain if the GPIO chip functions potentially sleep.
3244 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3246 VALIDATE_DESC_VOID(desc);
3247 /* Should be using gpiod_set_value_cansleep() */
3248 WARN_ON(desc->gdev->chip->can_sleep);
3249 gpiod_set_raw_value_commit(desc, value);
3251 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3254 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3255 * @desc: the descriptor to set the value on
3256 * @value: value to set
3258 * This sets the value of a GPIO line backing a descriptor, applying
3259 * different semantic quirks like active low and open drain/source
3262 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3264 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3266 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3267 gpio_set_open_drain_value_commit(desc, value);
3268 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3269 gpio_set_open_source_value_commit(desc, value);
3271 gpiod_set_raw_value_commit(desc, value);
3275 * gpiod_set_value() - assign a gpio's value
3276 * @desc: gpio whose value will be assigned
3277 * @value: value to assign
3279 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3280 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3282 * This function should be called from contexts where we cannot sleep, and will
3283 * complain if the GPIO chip functions potentially sleep.
3285 void gpiod_set_value(struct gpio_desc *desc, int value)
3287 VALIDATE_DESC_VOID(desc);
3288 WARN_ON(desc->gdev->chip->can_sleep);
3289 gpiod_set_value_nocheck(desc, value);
3291 EXPORT_SYMBOL_GPL(gpiod_set_value);
3294 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3295 * @array_size: number of elements in the descriptor array / value bitmap
3296 * @desc_array: array of GPIO descriptors whose values will be assigned
3297 * @array_info: information on applicability of fast bitmap processing path
3298 * @value_bitmap: bitmap of values to assign
3300 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3301 * without regard for their ACTIVE_LOW status.
3303 * This function should be called from contexts where we cannot sleep, and will
3304 * complain if the GPIO chip functions potentially sleep.
3306 int gpiod_set_raw_array_value(unsigned int array_size,
3307 struct gpio_desc **desc_array,
3308 struct gpio_array *array_info,
3309 unsigned long *value_bitmap)
3313 return gpiod_set_array_value_complex(true, false, array_size,
3314 desc_array, array_info, value_bitmap);
3316 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3319 * gpiod_set_array_value() - assign values to an array of GPIOs
3320 * @array_size: number of elements in the descriptor array / value bitmap
3321 * @desc_array: array of GPIO descriptors whose values will be assigned
3322 * @array_info: information on applicability of fast bitmap processing path
3323 * @value_bitmap: bitmap of values to assign
3325 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3328 * This function should be called from contexts where we cannot sleep, and will
3329 * complain if the GPIO chip functions potentially sleep.
3331 int gpiod_set_array_value(unsigned int array_size,
3332 struct gpio_desc **desc_array,
3333 struct gpio_array *array_info,
3334 unsigned long *value_bitmap)
3338 return gpiod_set_array_value_complex(false, false, array_size,
3339 desc_array, array_info,
3342 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3345 * gpiod_cansleep() - report whether gpio value access may sleep
3346 * @desc: gpio to check
3349 int gpiod_cansleep(const struct gpio_desc *desc)
3351 VALIDATE_DESC(desc);
3352 return desc->gdev->chip->can_sleep;
3354 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3357 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3358 * @desc: gpio to set the consumer name on
3359 * @name: the new consumer name
3361 void gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3363 VALIDATE_DESC_VOID(desc);
3364 /* Just overwrite whatever the previous name was */
3367 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3370 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3371 * @desc: gpio whose IRQ will be returned (already requested)
3373 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3376 int gpiod_to_irq(const struct gpio_desc *desc)
3378 struct gpio_chip *chip;
3382 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3383 * requires this function to not return zero on an invalid descriptor
3384 * but rather a negative error number.
3386 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3389 chip = desc->gdev->chip;
3390 offset = gpio_chip_hwgpio(desc);
3392 int retirq = chip->to_irq(chip, offset);
3394 /* Zero means NO_IRQ */
3402 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3405 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3406 * @chip: the chip the GPIO to lock belongs to
3407 * @offset: the offset of the GPIO to lock as IRQ
3409 * This is used directly by GPIO drivers that want to lock down
3410 * a certain GPIO line to be used for IRQs.
3412 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
3414 struct gpio_desc *desc;
3416 desc = gpiochip_get_desc(chip, offset);
3418 return PTR_ERR(desc);
3421 * If it's fast: flush the direction setting if something changed
3424 if (!chip->can_sleep && chip->get_direction) {
3425 int dir = gpiod_get_direction(desc);
3428 chip_err(chip, "%s: cannot get GPIO direction\n",
3434 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
3436 "%s: tried to flag a GPIO set as output for IRQ\n",
3441 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3442 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3445 * If the consumer has not set up a label (such as when the
3446 * IRQ is referenced from .to_irq()) we set up a label here
3447 * so it is clear this is used as an interrupt.
3450 desc_set_label(desc, "interrupt");
3454 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3457 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3458 * @chip: the chip the GPIO to lock belongs to
3459 * @offset: the offset of the GPIO to lock as IRQ
3461 * This is used directly by GPIO drivers that want to indicate
3462 * that a certain GPIO is no longer used exclusively for IRQ.
3464 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
3466 struct gpio_desc *desc;
3468 desc = gpiochip_get_desc(chip, offset);
3472 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3473 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3475 /* If we only had this marking, erase it */
3476 if (desc->label && !strcmp(desc->label, "interrupt"))
3477 desc_set_label(desc, NULL);
3479 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3481 void gpiochip_disable_irq(struct gpio_chip *chip, unsigned int offset)
3483 struct gpio_desc *desc = gpiochip_get_desc(chip, offset);
3485 if (!IS_ERR(desc) &&
3486 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3487 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3489 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3491 void gpiochip_enable_irq(struct gpio_chip *chip, unsigned int offset)
3493 struct gpio_desc *desc = gpiochip_get_desc(chip, offset);
3495 if (!IS_ERR(desc) &&
3496 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3497 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags));
3498 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3501 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3503 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
3505 if (offset >= chip->ngpio)
3508 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
3510 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3512 int gpiochip_reqres_irq(struct gpio_chip *chip, unsigned int offset)
3516 if (!try_module_get(chip->gpiodev->owner))
3519 ret = gpiochip_lock_as_irq(chip, offset);
3521 chip_err(chip, "unable to lock HW IRQ %u for IRQ\n", offset);
3522 module_put(chip->gpiodev->owner);
3527 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3529 void gpiochip_relres_irq(struct gpio_chip *chip, unsigned int offset)
3531 gpiochip_unlock_as_irq(chip, offset);
3532 module_put(chip->gpiodev->owner);
3534 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3536 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
3538 if (offset >= chip->ngpio)
3541 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
3543 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3545 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
3547 if (offset >= chip->ngpio)
3550 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
3552 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3554 bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
3556 if (offset >= chip->ngpio)
3559 return !test_bit(FLAG_TRANSITORY, &chip->gpiodev->descs[offset].flags);
3561 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3564 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3565 * @desc: gpio whose value will be returned
3567 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3568 * its ACTIVE_LOW status, or negative errno on failure.
3570 * This function is to be called from contexts that can sleep.
3572 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3574 might_sleep_if(extra_checks);
3575 VALIDATE_DESC(desc);
3576 return gpiod_get_raw_value_commit(desc);
3578 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3581 * gpiod_get_value_cansleep() - return a gpio's value
3582 * @desc: gpio whose value will be returned
3584 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3585 * account, or negative errno on failure.
3587 * This function is to be called from contexts that can sleep.
3589 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3593 might_sleep_if(extra_checks);
3594 VALIDATE_DESC(desc);
3595 value = gpiod_get_raw_value_commit(desc);
3599 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3604 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3607 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3608 * @array_size: number of elements in the descriptor array / value bitmap
3609 * @desc_array: array of GPIO descriptors whose values will be read
3610 * @array_info: information on applicability of fast bitmap processing path
3611 * @value_bitmap: bitmap to store the read values
3613 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3614 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3615 * else an error code.
3617 * This function is to be called from contexts that can sleep.
3619 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3620 struct gpio_desc **desc_array,
3621 struct gpio_array *array_info,
3622 unsigned long *value_bitmap)
3624 might_sleep_if(extra_checks);
3627 return gpiod_get_array_value_complex(true, true, array_size,
3628 desc_array, array_info,
3631 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3634 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3635 * @array_size: number of elements in the descriptor array / value bitmap
3636 * @desc_array: array of GPIO descriptors whose values will be read
3637 * @array_info: information on applicability of fast bitmap processing path
3638 * @value_bitmap: bitmap to store the read values
3640 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3641 * into account. Return 0 in case of success, else an error code.
3643 * This function is to be called from contexts that can sleep.
3645 int gpiod_get_array_value_cansleep(unsigned int array_size,
3646 struct gpio_desc **desc_array,
3647 struct gpio_array *array_info,
3648 unsigned long *value_bitmap)
3650 might_sleep_if(extra_checks);
3653 return gpiod_get_array_value_complex(false, true, array_size,
3654 desc_array, array_info,
3657 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3660 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3661 * @desc: gpio whose value will be assigned
3662 * @value: value to assign
3664 * Set the raw value of the GPIO, i.e. the value of its physical line without
3665 * regard for its ACTIVE_LOW status.
3667 * This function is to be called from contexts that can sleep.
3669 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3671 might_sleep_if(extra_checks);
3672 VALIDATE_DESC_VOID(desc);
3673 gpiod_set_raw_value_commit(desc, value);
3675 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3678 * gpiod_set_value_cansleep() - assign a gpio's value
3679 * @desc: gpio whose value will be assigned
3680 * @value: value to assign
3682 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3685 * This function is to be called from contexts that can sleep.
3687 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3689 might_sleep_if(extra_checks);
3690 VALIDATE_DESC_VOID(desc);
3691 gpiod_set_value_nocheck(desc, value);
3693 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3696 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3697 * @array_size: number of elements in the descriptor array / value bitmap
3698 * @desc_array: array of GPIO descriptors whose values will be assigned
3699 * @array_info: information on applicability of fast bitmap processing path
3700 * @value_bitmap: bitmap of values to assign
3702 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3703 * without regard for their ACTIVE_LOW status.
3705 * This function is to be called from contexts that can sleep.
3707 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3708 struct gpio_desc **desc_array,
3709 struct gpio_array *array_info,
3710 unsigned long *value_bitmap)
3712 might_sleep_if(extra_checks);
3715 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3716 array_info, value_bitmap);
3718 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3721 * gpiod_add_lookup_tables() - register GPIO device consumers
3722 * @tables: list of tables of consumers to register
3723 * @n: number of tables in the list
3725 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3729 mutex_lock(&gpio_lookup_lock);
3731 for (i = 0; i < n; i++)
3732 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3734 mutex_unlock(&gpio_lookup_lock);
3738 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3739 * @array_size: number of elements in the descriptor array / value bitmap
3740 * @desc_array: array of GPIO descriptors whose values will be assigned
3741 * @array_info: information on applicability of fast bitmap processing path
3742 * @value_bitmap: bitmap of values to assign
3744 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3747 * This function is to be called from contexts that can sleep.
3749 int gpiod_set_array_value_cansleep(unsigned int array_size,
3750 struct gpio_desc **desc_array,
3751 struct gpio_array *array_info,
3752 unsigned long *value_bitmap)
3754 might_sleep_if(extra_checks);
3757 return gpiod_set_array_value_complex(false, true, array_size,
3758 desc_array, array_info,
3761 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3764 * gpiod_add_lookup_table() - register GPIO device consumers
3765 * @table: table of consumers to register
3767 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3769 mutex_lock(&gpio_lookup_lock);
3771 list_add_tail(&table->list, &gpio_lookup_list);
3773 mutex_unlock(&gpio_lookup_lock);
3775 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3778 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3779 * @table: table of consumers to unregister
3781 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3783 mutex_lock(&gpio_lookup_lock);
3785 list_del(&table->list);
3787 mutex_unlock(&gpio_lookup_lock);
3789 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3792 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
3793 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
3795 void gpiod_add_hogs(struct gpiod_hog *hogs)
3797 struct gpio_chip *chip;
3798 struct gpiod_hog *hog;
3800 mutex_lock(&gpio_machine_hogs_mutex);
3802 for (hog = &hogs[0]; hog->chip_label; hog++) {
3803 list_add_tail(&hog->list, &gpio_machine_hogs);
3806 * The chip may have been registered earlier, so check if it
3807 * exists and, if so, try to hog the line now.
3809 chip = find_chip_by_name(hog->chip_label);
3811 gpiochip_machine_hog(chip, hog);
3814 mutex_unlock(&gpio_machine_hogs_mutex);
3816 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
3818 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3820 const char *dev_id = dev ? dev_name(dev) : NULL;
3821 struct gpiod_lookup_table *table;
3823 mutex_lock(&gpio_lookup_lock);
3825 list_for_each_entry(table, &gpio_lookup_list, list) {
3826 if (table->dev_id && dev_id) {
3828 * Valid strings on both ends, must be identical to have
3831 if (!strcmp(table->dev_id, dev_id))
3835 * One of the pointers is NULL, so both must be to have
3838 if (dev_id == table->dev_id)
3845 mutex_unlock(&gpio_lookup_lock);
3849 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3851 enum gpio_lookup_flags *flags)
3853 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3854 struct gpiod_lookup_table *table;
3855 struct gpiod_lookup *p;
3857 table = gpiod_find_lookup_table(dev);
3861 for (p = &table->table[0]; p->chip_label; p++) {
3862 struct gpio_chip *chip;
3864 /* idx must always match exactly */
3868 /* If the lookup entry has a con_id, require exact match */
3869 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3872 chip = find_chip_by_name(p->chip_label);
3876 * As the lookup table indicates a chip with
3877 * p->chip_label should exist, assume it may
3878 * still appear later and let the interested
3879 * consumer be probed again or let the Deferred
3880 * Probe infrastructure handle the error.
3882 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
3884 return ERR_PTR(-EPROBE_DEFER);
3887 if (chip->ngpio <= p->chip_hwnum) {
3889 "requested GPIO %d is out of range [0..%d] for chip %s\n",
3890 idx, chip->ngpio, chip->label);
3891 return ERR_PTR(-EINVAL);
3894 desc = gpiochip_get_desc(chip, p->chip_hwnum);
3903 static int dt_gpio_count(struct device *dev, const char *con_id)
3909 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3911 snprintf(propname, sizeof(propname), "%s-%s",
3912 con_id, gpio_suffixes[i]);
3914 snprintf(propname, sizeof(propname), "%s",
3917 ret = of_gpio_named_count(dev->of_node, propname);
3921 return ret ? ret : -ENOENT;
3924 static int platform_gpio_count(struct device *dev, const char *con_id)
3926 struct gpiod_lookup_table *table;
3927 struct gpiod_lookup *p;
3928 unsigned int count = 0;
3930 table = gpiod_find_lookup_table(dev);
3934 for (p = &table->table[0]; p->chip_label; p++) {
3935 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3936 (!con_id && !p->con_id))
3946 * gpiod_count - return the number of GPIOs associated with a device / function
3947 * or -ENOENT if no GPIO has been assigned to the requested function
3948 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3949 * @con_id: function within the GPIO consumer
3951 int gpiod_count(struct device *dev, const char *con_id)
3953 int count = -ENOENT;
3955 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
3956 count = dt_gpio_count(dev, con_id);
3957 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
3958 count = acpi_gpio_count(dev, con_id);
3961 count = platform_gpio_count(dev, con_id);
3965 EXPORT_SYMBOL_GPL(gpiod_count);
3968 * gpiod_get - obtain a GPIO for a given GPIO function
3969 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3970 * @con_id: function within the GPIO consumer
3971 * @flags: optional GPIO initialization flags
3973 * Return the GPIO descriptor corresponding to the function con_id of device
3974 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3975 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3977 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3978 enum gpiod_flags flags)
3980 return gpiod_get_index(dev, con_id, 0, flags);
3982 EXPORT_SYMBOL_GPL(gpiod_get);
3985 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3986 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3987 * @con_id: function within the GPIO consumer
3988 * @flags: optional GPIO initialization flags
3990 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3991 * the requested function it will return NULL. This is convenient for drivers
3992 * that need to handle optional GPIOs.
3994 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3996 enum gpiod_flags flags)
3998 return gpiod_get_index_optional(dev, con_id, 0, flags);
4000 EXPORT_SYMBOL_GPL(gpiod_get_optional);
4004 * gpiod_configure_flags - helper function to configure a given GPIO
4005 * @desc: gpio whose value will be assigned
4006 * @con_id: function within the GPIO consumer
4007 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
4009 * @dflags: gpiod_flags - optional GPIO initialization flags
4011 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
4012 * requested function and/or index, or another IS_ERR() code if an error
4013 * occurred while trying to acquire the GPIO.
4015 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
4016 unsigned long lflags, enum gpiod_flags dflags)
4020 if (lflags & GPIO_ACTIVE_LOW)
4021 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
4023 if (lflags & GPIO_OPEN_DRAIN)
4024 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4025 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
4027 * This enforces open drain mode from the consumer side.
4028 * This is necessary for some busses like I2C, but the lookup
4029 * should *REALLY* have specified them as open drain in the
4030 * first place, so print a little warning here.
4032 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4034 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
4037 if (lflags & GPIO_OPEN_SOURCE)
4038 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
4040 status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
4044 /* No particular flag request, return here... */
4045 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
4046 pr_debug("no flags found for %s\n", con_id);
4051 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
4052 status = gpiod_direction_output(desc,
4053 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
4055 status = gpiod_direction_input(desc);
4061 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
4062 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4063 * @con_id: function within the GPIO consumer
4064 * @idx: index of the GPIO to obtain in the consumer
4065 * @flags: optional GPIO initialization flags
4067 * This variant of gpiod_get() allows to access GPIOs other than the first
4068 * defined one for functions that define several GPIOs.
4070 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
4071 * requested function and/or index, or another IS_ERR() code if an error
4072 * occurred while trying to acquire the GPIO.
4074 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
4077 enum gpiod_flags flags)
4079 struct gpio_desc *desc = NULL;
4081 enum gpio_lookup_flags lookupflags = 0;
4082 /* Maybe we have a device name, maybe not */
4083 const char *devname = dev ? dev_name(dev) : "?";
4085 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
4088 /* Using device tree? */
4089 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
4090 dev_dbg(dev, "using device tree for GPIO lookup\n");
4091 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
4092 } else if (ACPI_COMPANION(dev)) {
4093 dev_dbg(dev, "using ACPI for GPIO lookup\n");
4094 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
4099 * Either we are not using DT or ACPI, or their lookup did not return
4100 * a result. In that case, use platform lookup as a fallback.
4102 if (!desc || desc == ERR_PTR(-ENOENT)) {
4103 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
4104 desc = gpiod_find(dev, con_id, idx, &lookupflags);
4108 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
4113 * If a connection label was passed use that, else attempt to use
4114 * the device name as label
4116 status = gpiod_request(desc, con_id ? con_id : devname);
4118 if (status == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
4120 * This happens when there are several consumers for
4121 * the same GPIO line: we just return here without
4122 * further initialization. It is a bit if a hack.
4123 * This is necessary to support fixed regulators.
4125 * FIXME: Make this more sane and safe.
4127 dev_info(dev, "nonexclusive access to GPIO for %s\n",
4128 con_id ? con_id : devname);
4131 return ERR_PTR(status);
4135 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
4137 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
4139 return ERR_PTR(status);
4144 EXPORT_SYMBOL_GPL(gpiod_get_index);
4147 * gpiod_get_from_of_node() - obtain a GPIO from an OF node
4148 * @node: handle of the OF node
4149 * @propname: name of the DT property representing the GPIO
4150 * @index: index of the GPIO to obtain for the consumer
4151 * @dflags: GPIO initialization flags
4152 * @label: label to attach to the requested GPIO
4155 * On successful request the GPIO pin is configured in accordance with
4156 * provided @dflags. If the node does not have the requested GPIO
4157 * property, NULL is returned.
4159 * In case of error an ERR_PTR() is returned.
4161 struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
4162 const char *propname, int index,
4163 enum gpiod_flags dflags,
4166 struct gpio_desc *desc;
4167 unsigned long lflags = 0;
4168 enum of_gpio_flags flags;
4169 bool active_low = false;
4170 bool single_ended = false;
4171 bool open_drain = false;
4172 bool transitory = false;
4175 desc = of_get_named_gpiod_flags(node, propname,
4178 if (!desc || IS_ERR(desc)) {
4179 /* If it is not there, just return NULL */
4180 if (PTR_ERR(desc) == -ENOENT)
4185 active_low = flags & OF_GPIO_ACTIVE_LOW;
4186 single_ended = flags & OF_GPIO_SINGLE_ENDED;
4187 open_drain = flags & OF_GPIO_OPEN_DRAIN;
4188 transitory = flags & OF_GPIO_TRANSITORY;
4190 ret = gpiod_request(desc, label);
4192 return ERR_PTR(ret);
4195 lflags |= GPIO_ACTIVE_LOW;
4199 lflags |= GPIO_OPEN_DRAIN;
4201 lflags |= GPIO_OPEN_SOURCE;
4205 lflags |= GPIO_TRANSITORY;
4207 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4210 return ERR_PTR(ret);
4215 EXPORT_SYMBOL(gpiod_get_from_of_node);
4218 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
4219 * @fwnode: handle of the firmware node
4220 * @propname: name of the firmware property representing the GPIO
4221 * @index: index of the GPIO to obtain for the consumer
4222 * @dflags: GPIO initialization flags
4223 * @label: label to attach to the requested GPIO
4225 * This function can be used for drivers that get their configuration
4226 * from opaque firmware.
4228 * The function properly finds the corresponding GPIO using whatever is the
4229 * underlying firmware interface and then makes sure that the GPIO
4230 * descriptor is requested before it is returned to the caller.
4233 * On successful request the GPIO pin is configured in accordance with
4236 * In case of error an ERR_PTR() is returned.
4238 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
4239 const char *propname, int index,
4240 enum gpiod_flags dflags,
4243 struct gpio_desc *desc = ERR_PTR(-ENODEV);
4244 unsigned long lflags = 0;
4248 return ERR_PTR(-EINVAL);
4250 if (is_of_node(fwnode)) {
4251 desc = gpiod_get_from_of_node(to_of_node(fwnode),
4256 } else if (is_acpi_node(fwnode)) {
4257 struct acpi_gpio_info info;
4259 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4263 acpi_gpio_update_gpiod_flags(&dflags, &info);
4265 if (info.polarity == GPIO_ACTIVE_LOW)
4266 lflags |= GPIO_ACTIVE_LOW;
4269 /* Currently only ACPI takes this path */
4270 ret = gpiod_request(desc, label);
4272 return ERR_PTR(ret);
4274 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4277 return ERR_PTR(ret);
4282 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4285 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4287 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4288 * @con_id: function within the GPIO consumer
4289 * @index: index of the GPIO to obtain in the consumer
4290 * @flags: optional GPIO initialization flags
4292 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4293 * specified index was assigned to the requested function it will return NULL.
4294 * This is convenient for drivers that need to handle optional GPIOs.
4296 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4299 enum gpiod_flags flags)
4301 struct gpio_desc *desc;
4303 desc = gpiod_get_index(dev, con_id, index, flags);
4305 if (PTR_ERR(desc) == -ENOENT)
4311 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4314 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4315 * @desc: gpio whose value will be assigned
4316 * @name: gpio line name
4317 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
4319 * @dflags: gpiod_flags - optional GPIO initialization flags
4321 int gpiod_hog(struct gpio_desc *desc, const char *name,
4322 unsigned long lflags, enum gpiod_flags dflags)
4324 struct gpio_chip *chip;
4325 struct gpio_desc *local_desc;
4329 chip = gpiod_to_chip(desc);
4330 hwnum = gpio_chip_hwgpio(desc);
4332 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
4333 if (IS_ERR(local_desc)) {
4334 status = PTR_ERR(local_desc);
4335 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4336 name, chip->label, hwnum, status);
4340 status = gpiod_configure_flags(desc, name, lflags, dflags);
4342 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
4343 name, chip->label, hwnum, status);
4344 gpiochip_free_own_desc(desc);
4348 /* Mark GPIO as hogged so it can be identified and removed later */
4349 set_bit(FLAG_IS_HOGGED, &desc->flags);
4351 pr_info("GPIO line %d (%s) hogged as %s%s\n",
4352 desc_to_gpio(desc), name,
4353 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4354 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
4355 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
4361 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4362 * @chip: gpio chip to act on
4364 * This is only used by of_gpiochip_remove to free hogged gpios
4366 static void gpiochip_free_hogs(struct gpio_chip *chip)
4370 for (id = 0; id < chip->ngpio; id++) {
4371 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
4372 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
4377 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4378 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4379 * @con_id: function within the GPIO consumer
4380 * @flags: optional GPIO initialization flags
4382 * This function acquires all the GPIOs defined under a given function.
4384 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4385 * no GPIO has been assigned to the requested function, or another IS_ERR()
4386 * code if an error occurred while trying to acquire the GPIOs.
4388 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4390 enum gpiod_flags flags)
4392 struct gpio_desc *desc;
4393 struct gpio_descs *descs;
4394 struct gpio_array *array_info = NULL;
4395 struct gpio_chip *chip;
4396 int count, bitmap_size;
4398 count = gpiod_count(dev, con_id);
4400 return ERR_PTR(count);
4402 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4404 return ERR_PTR(-ENOMEM);
4406 for (descs->ndescs = 0; descs->ndescs < count; ) {
4407 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4409 gpiod_put_array(descs);
4410 return ERR_CAST(desc);
4413 descs->desc[descs->ndescs] = desc;
4415 chip = gpiod_to_chip(desc);
4417 * If pin hardware number of array member 0 is also 0, select
4418 * its chip as a candidate for fast bitmap processing path.
4420 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4421 struct gpio_descs *array;
4423 bitmap_size = BITS_TO_LONGS(chip->ngpio > count ?
4424 chip->ngpio : count);
4426 array = kzalloc(struct_size(descs, desc, count) +
4427 struct_size(array_info, invert_mask,
4428 3 * bitmap_size), GFP_KERNEL);
4430 gpiod_put_array(descs);
4431 return ERR_PTR(-ENOMEM);
4434 memcpy(array, descs,
4435 struct_size(descs, desc, descs->ndescs + 1));
4439 array_info = (void *)(descs->desc + count);
4440 array_info->get_mask = array_info->invert_mask +
4442 array_info->set_mask = array_info->get_mask +
4445 array_info->desc = descs->desc;
4446 array_info->size = count;
4447 array_info->chip = chip;
4448 bitmap_set(array_info->get_mask, descs->ndescs,
4449 count - descs->ndescs);
4450 bitmap_set(array_info->set_mask, descs->ndescs,
4451 count - descs->ndescs);
4452 descs->info = array_info;
4454 /* Unmark array members which don't belong to the 'fast' chip */
4455 if (array_info && array_info->chip != chip) {
4456 __clear_bit(descs->ndescs, array_info->get_mask);
4457 __clear_bit(descs->ndescs, array_info->set_mask);
4460 * Detect array members which belong to the 'fast' chip
4461 * but their pins are not in hardware order.
4463 else if (array_info &&
4464 gpio_chip_hwgpio(desc) != descs->ndescs) {
4466 * Don't use fast path if all array members processed so
4467 * far belong to the same chip as this one but its pin
4468 * hardware number is different from its array index.
4470 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4473 __clear_bit(descs->ndescs,
4474 array_info->get_mask);
4475 __clear_bit(descs->ndescs,
4476 array_info->set_mask);
4478 } else if (array_info) {
4479 /* Exclude open drain or open source from fast output */
4480 if (gpiochip_line_is_open_drain(chip, descs->ndescs) ||
4481 gpiochip_line_is_open_source(chip, descs->ndescs))
4482 __clear_bit(descs->ndescs,
4483 array_info->set_mask);
4484 /* Identify 'fast' pins which require invertion */
4485 if (gpiod_is_active_low(desc))
4486 __set_bit(descs->ndescs,
4487 array_info->invert_mask);
4494 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4495 array_info->chip->label, array_info->size,
4496 *array_info->get_mask, *array_info->set_mask,
4497 *array_info->invert_mask);
4500 EXPORT_SYMBOL_GPL(gpiod_get_array);
4503 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4505 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4506 * @con_id: function within the GPIO consumer
4507 * @flags: optional GPIO initialization flags
4509 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4510 * assigned to the requested function it will return NULL.
4512 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4514 enum gpiod_flags flags)
4516 struct gpio_descs *descs;
4518 descs = gpiod_get_array(dev, con_id, flags);
4519 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
4524 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4527 * gpiod_put - dispose of a GPIO descriptor
4528 * @desc: GPIO descriptor to dispose of
4530 * No descriptor can be used after gpiod_put() has been called on it.
4532 void gpiod_put(struct gpio_desc *desc)
4536 EXPORT_SYMBOL_GPL(gpiod_put);
4539 * gpiod_put_array - dispose of multiple GPIO descriptors
4540 * @descs: struct gpio_descs containing an array of descriptors
4542 void gpiod_put_array(struct gpio_descs *descs)
4546 for (i = 0; i < descs->ndescs; i++)
4547 gpiod_put(descs->desc[i]);
4551 EXPORT_SYMBOL_GPL(gpiod_put_array);
4553 static int __init gpiolib_dev_init(void)
4557 /* Register GPIO sysfs bus */
4558 ret = bus_register(&gpio_bus_type);
4560 pr_err("gpiolib: could not register GPIO bus type\n");
4564 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
4566 pr_err("gpiolib: failed to allocate char dev region\n");
4567 bus_unregister(&gpio_bus_type);
4569 gpiolib_initialized = true;
4570 gpiochip_setup_devs();
4574 core_initcall(gpiolib_dev_init);
4576 #ifdef CONFIG_DEBUG_FS
4578 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4581 struct gpio_chip *chip = gdev->chip;
4582 unsigned gpio = gdev->base;
4583 struct gpio_desc *gdesc = &gdev->descs[0];
4588 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4589 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4591 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4597 gpiod_get_direction(gdesc);
4598 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4599 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4600 active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
4601 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
4602 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4603 is_out ? "out" : "in ",
4604 chip->get ? (chip->get(chip, i) ? "hi" : "lo") : "? ",
4605 is_irq ? "IRQ " : "",
4606 active_low ? "ACTIVE LOW" : "");
4607 seq_printf(s, "\n");
4611 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4613 unsigned long flags;
4614 struct gpio_device *gdev = NULL;
4615 loff_t index = *pos;
4619 spin_lock_irqsave(&gpio_lock, flags);
4620 list_for_each_entry(gdev, &gpio_devices, list)
4622 spin_unlock_irqrestore(&gpio_lock, flags);
4625 spin_unlock_irqrestore(&gpio_lock, flags);
4630 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4632 unsigned long flags;
4633 struct gpio_device *gdev = v;
4636 spin_lock_irqsave(&gpio_lock, flags);
4637 if (list_is_last(&gdev->list, &gpio_devices))
4640 ret = list_entry(gdev->list.next, struct gpio_device, list);
4641 spin_unlock_irqrestore(&gpio_lock, flags);
4649 static void gpiolib_seq_stop(struct seq_file *s, void *v)
4653 static int gpiolib_seq_show(struct seq_file *s, void *v)
4655 struct gpio_device *gdev = v;
4656 struct gpio_chip *chip = gdev->chip;
4657 struct device *parent;
4660 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4661 dev_name(&gdev->dev));
4665 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4666 dev_name(&gdev->dev),
4667 gdev->base, gdev->base + gdev->ngpio - 1);
4668 parent = chip->parent;
4670 seq_printf(s, ", parent: %s/%s",
4671 parent->bus ? parent->bus->name : "no-bus",
4674 seq_printf(s, ", %s", chip->label);
4675 if (chip->can_sleep)
4676 seq_printf(s, ", can sleep");
4677 seq_printf(s, ":\n");
4680 chip->dbg_show(s, chip);
4682 gpiolib_dbg_show(s, gdev);
4687 static const struct seq_operations gpiolib_seq_ops = {
4688 .start = gpiolib_seq_start,
4689 .next = gpiolib_seq_next,
4690 .stop = gpiolib_seq_stop,
4691 .show = gpiolib_seq_show,
4694 static int gpiolib_open(struct inode *inode, struct file *file)
4696 return seq_open(file, &gpiolib_seq_ops);
4699 static const struct file_operations gpiolib_operations = {
4700 .owner = THIS_MODULE,
4701 .open = gpiolib_open,
4703 .llseek = seq_lseek,
4704 .release = seq_release,
4707 static int __init gpiolib_debugfs_init(void)
4709 /* /sys/kernel/debug/gpio */
4710 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
4711 NULL, NULL, &gpiolib_operations);
4714 subsys_initcall(gpiolib_debugfs_init);
4716 #endif /* DEBUG_FS */