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);
1433 /* failures here can mean systems won't boot... */
1434 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1435 gdev->base, gdev->base + gdev->ngpio - 1,
1436 chip->label ? : "generic", status);
1440 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1443 * gpiochip_get_data() - get per-subdriver data for the chip
1447 * The per-subdriver data for the chip.
1449 void *gpiochip_get_data(struct gpio_chip *chip)
1451 return chip->gpiodev->data;
1453 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1456 * gpiochip_remove() - unregister a gpio_chip
1457 * @chip: the chip to unregister
1459 * A gpio_chip with any GPIOs still requested may not be removed.
1461 void gpiochip_remove(struct gpio_chip *chip)
1463 struct gpio_device *gdev = chip->gpiodev;
1464 struct gpio_desc *desc;
1465 unsigned long flags;
1467 bool requested = false;
1469 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1470 gpiochip_sysfs_unregister(gdev);
1471 gpiochip_free_hogs(chip);
1472 /* Numb the device, cancelling all outstanding operations */
1474 gpiochip_irqchip_remove(chip);
1475 acpi_gpiochip_remove(chip);
1476 gpiochip_remove_pin_ranges(chip);
1477 of_gpiochip_remove(chip);
1478 gpiochip_free_valid_mask(chip);
1480 * We accept no more calls into the driver from this point, so
1481 * NULL the driver data pointer
1485 spin_lock_irqsave(&gpio_lock, flags);
1486 for (i = 0; i < gdev->ngpio; i++) {
1487 desc = &gdev->descs[i];
1488 if (test_bit(FLAG_REQUESTED, &desc->flags))
1491 spin_unlock_irqrestore(&gpio_lock, flags);
1494 dev_crit(&gdev->dev,
1495 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1498 * The gpiochip side puts its use of the device to rest here:
1499 * if there are no userspace clients, the chardev and device will
1500 * be removed, else it will be dangling until the last user is
1503 cdev_device_del(&gdev->chrdev, &gdev->dev);
1504 put_device(&gdev->dev);
1506 EXPORT_SYMBOL_GPL(gpiochip_remove);
1508 static void devm_gpio_chip_release(struct device *dev, void *res)
1510 struct gpio_chip *chip = *(struct gpio_chip **)res;
1512 gpiochip_remove(chip);
1515 static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
1518 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 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1569 * @dev: device for which which resource was allocated
1570 * @chip: the chip to remove
1572 * A gpio_chip with any GPIOs still requested may not be removed.
1574 void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
1578 ret = devres_release(dev, devm_gpio_chip_release,
1579 devm_gpio_chip_match, chip);
1582 EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
1585 * gpiochip_find() - iterator for locating a specific gpio_chip
1586 * @data: data to pass to match function
1587 * @match: Callback function to check gpio_chip
1589 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1590 * determined by a user supplied @match callback. The callback should return
1591 * 0 if the device doesn't match and non-zero if it does. If the callback is
1592 * non-zero, this function will return to the caller and not iterate over any
1595 struct gpio_chip *gpiochip_find(void *data,
1596 int (*match)(struct gpio_chip *chip,
1599 struct gpio_device *gdev;
1600 struct gpio_chip *chip = NULL;
1601 unsigned long flags;
1603 spin_lock_irqsave(&gpio_lock, flags);
1604 list_for_each_entry(gdev, &gpio_devices, list)
1605 if (gdev->chip && match(gdev->chip, data)) {
1610 spin_unlock_irqrestore(&gpio_lock, flags);
1614 EXPORT_SYMBOL_GPL(gpiochip_find);
1616 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1618 const char *name = data;
1620 return !strcmp(chip->label, name);
1623 static struct gpio_chip *find_chip_by_name(const char *name)
1625 return gpiochip_find((void *)name, gpiochip_match_name);
1628 #ifdef CONFIG_GPIOLIB_IRQCHIP
1631 * The following is irqchip helper code for gpiochips.
1634 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1636 if (!gpiochip->irq.need_valid_mask)
1639 gpiochip->irq.valid_mask = gpiochip_allocate_mask(gpiochip);
1640 if (!gpiochip->irq.valid_mask)
1646 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1648 kfree(gpiochip->irq.valid_mask);
1649 gpiochip->irq.valid_mask = NULL;
1652 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1653 unsigned int offset)
1655 if (!gpiochip_line_is_valid(gpiochip, offset))
1657 /* No mask means all valid */
1658 if (likely(!gpiochip->irq.valid_mask))
1660 return test_bit(offset, gpiochip->irq.valid_mask);
1662 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1665 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1666 * @gpiochip: the gpiochip to set the irqchip chain to
1667 * @parent_irq: the irq number corresponding to the parent IRQ for this
1669 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1670 * coming out of the gpiochip. If the interrupt is nested rather than
1671 * cascaded, pass NULL in this handler argument
1673 static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
1674 unsigned int parent_irq,
1675 irq_flow_handler_t parent_handler)
1677 if (!gpiochip->irq.domain) {
1678 chip_err(gpiochip, "called %s before setting up irqchip\n",
1683 if (parent_handler) {
1684 if (gpiochip->can_sleep) {
1686 "you cannot have chained interrupts on a chip that may sleep\n");
1690 * The parent irqchip is already using the chip_data for this
1691 * irqchip, so our callbacks simply use the handler_data.
1693 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1696 gpiochip->irq.parent_irq = parent_irq;
1697 gpiochip->irq.parents = &gpiochip->irq.parent_irq;
1698 gpiochip->irq.num_parents = 1;
1703 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1704 * @gpiochip: the gpiochip to set the irqchip chain to
1705 * @irqchip: the irqchip to chain to the gpiochip
1706 * @parent_irq: the irq number corresponding to the parent IRQ for this
1708 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1709 * coming out of the gpiochip.
1711 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1712 struct irq_chip *irqchip,
1713 unsigned int parent_irq,
1714 irq_flow_handler_t parent_handler)
1716 if (gpiochip->irq.threaded) {
1717 chip_err(gpiochip, "tried to chain a threaded gpiochip\n");
1721 gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, parent_handler);
1723 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1726 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1727 * @gpiochip: the gpiochip to set the irqchip nested handler to
1728 * @irqchip: the irqchip to nest to the gpiochip
1729 * @parent_irq: the irq number corresponding to the parent IRQ for this
1732 void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1733 struct irq_chip *irqchip,
1734 unsigned int parent_irq)
1736 gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, NULL);
1738 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1741 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1742 * @d: the irqdomain used by this irqchip
1743 * @irq: the global irq number used by this GPIO irqchip irq
1744 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1746 * This function will set up the mapping for a certain IRQ line on a
1747 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1748 * stored inside the gpiochip.
1750 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1751 irq_hw_number_t hwirq)
1753 struct gpio_chip *chip = d->host_data;
1756 if (!gpiochip_irqchip_irq_valid(chip, hwirq))
1759 irq_set_chip_data(irq, chip);
1761 * This lock class tells lockdep that GPIO irqs are in a different
1762 * category than their parents, so it won't report false recursion.
1764 irq_set_lockdep_class(irq, chip->irq.lock_key, chip->irq.request_key);
1765 irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
1766 /* Chips that use nested thread handlers have them marked */
1767 if (chip->irq.threaded)
1768 irq_set_nested_thread(irq, 1);
1769 irq_set_noprobe(irq);
1771 if (chip->irq.num_parents == 1)
1772 err = irq_set_parent(irq, chip->irq.parents[0]);
1773 else if (chip->irq.map)
1774 err = irq_set_parent(irq, chip->irq.map[hwirq]);
1780 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1781 * is passed as default type.
1783 if (chip->irq.default_type != IRQ_TYPE_NONE)
1784 irq_set_irq_type(irq, chip->irq.default_type);
1788 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1790 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1792 struct gpio_chip *chip = d->host_data;
1794 if (chip->irq.threaded)
1795 irq_set_nested_thread(irq, 0);
1796 irq_set_chip_and_handler(irq, NULL, NULL);
1797 irq_set_chip_data(irq, NULL);
1799 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1801 static const struct irq_domain_ops gpiochip_domain_ops = {
1802 .map = gpiochip_irq_map,
1803 .unmap = gpiochip_irq_unmap,
1804 /* Virtually all GPIO irqchips are twocell:ed */
1805 .xlate = irq_domain_xlate_twocell,
1808 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1810 if (!gpiochip_irqchip_irq_valid(chip, offset))
1813 return irq_create_mapping(chip->irq.domain, offset);
1816 static int gpiochip_irq_reqres(struct irq_data *d)
1818 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1820 return gpiochip_reqres_irq(chip, d->hwirq);
1823 static void gpiochip_irq_relres(struct irq_data *d)
1825 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1827 gpiochip_relres_irq(chip, d->hwirq);
1830 static void gpiochip_irq_enable(struct irq_data *d)
1832 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1834 gpiochip_enable_irq(chip, d->hwirq);
1835 if (chip->irq.irq_enable)
1836 chip->irq.irq_enable(d);
1838 chip->irq.chip->irq_unmask(d);
1841 static void gpiochip_irq_disable(struct irq_data *d)
1843 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1845 if (chip->irq.irq_disable)
1846 chip->irq.irq_disable(d);
1848 chip->irq.chip->irq_mask(d);
1849 gpiochip_disable_irq(chip, d->hwirq);
1852 static void gpiochip_set_irq_hooks(struct gpio_chip *gpiochip)
1854 struct irq_chip *irqchip = gpiochip->irq.chip;
1856 if (!irqchip->irq_request_resources &&
1857 !irqchip->irq_release_resources) {
1858 irqchip->irq_request_resources = gpiochip_irq_reqres;
1859 irqchip->irq_release_resources = gpiochip_irq_relres;
1861 if (WARN_ON(gpiochip->irq.irq_enable))
1863 /* Check if the irqchip already has this hook... */
1864 if (irqchip->irq_enable == gpiochip_irq_enable) {
1866 * ...and if so, give a gentle warning that this is bad
1870 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1873 gpiochip->irq.irq_enable = irqchip->irq_enable;
1874 gpiochip->irq.irq_disable = irqchip->irq_disable;
1875 irqchip->irq_enable = gpiochip_irq_enable;
1876 irqchip->irq_disable = gpiochip_irq_disable;
1880 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1881 * @gpiochip: the GPIO chip to add the IRQ chip to
1882 * @lock_key: lockdep class for IRQ lock
1883 * @request_key: lockdep class for IRQ request
1885 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
1886 struct lock_class_key *lock_key,
1887 struct lock_class_key *request_key)
1889 struct irq_chip *irqchip = gpiochip->irq.chip;
1890 const struct irq_domain_ops *ops;
1891 struct device_node *np;
1898 if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {
1899 chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n");
1903 np = gpiochip->gpiodev->dev.of_node;
1904 type = gpiochip->irq.default_type;
1907 * Specifying a default trigger is a terrible idea if DT or ACPI is
1908 * used to configure the interrupts, as you may end up with
1909 * conflicting triggers. Tell the user, and reset to NONE.
1911 if (WARN(np && type != IRQ_TYPE_NONE,
1912 "%s: Ignoring %u default trigger\n", np->full_name, type))
1913 type = IRQ_TYPE_NONE;
1915 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1916 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1917 "Ignoring %u default trigger\n", type);
1918 type = IRQ_TYPE_NONE;
1921 gpiochip->to_irq = gpiochip_to_irq;
1922 gpiochip->irq.default_type = type;
1923 gpiochip->irq.lock_key = lock_key;
1924 gpiochip->irq.request_key = request_key;
1926 if (gpiochip->irq.domain_ops)
1927 ops = gpiochip->irq.domain_ops;
1929 ops = &gpiochip_domain_ops;
1931 gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
1932 gpiochip->irq.first,
1934 if (!gpiochip->irq.domain)
1937 if (gpiochip->irq.parent_handler) {
1938 void *data = gpiochip->irq.parent_handler_data ?: gpiochip;
1940 for (i = 0; i < gpiochip->irq.num_parents; i++) {
1942 * The parent IRQ chip is already using the chip_data
1943 * for this IRQ chip, so our callbacks simply use the
1946 irq_set_chained_handler_and_data(gpiochip->irq.parents[i],
1947 gpiochip->irq.parent_handler,
1952 gpiochip_set_irq_hooks(gpiochip);
1954 acpi_gpiochip_request_interrupts(gpiochip);
1960 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1961 * @gpiochip: the gpiochip to remove the irqchip from
1963 * This is called only from gpiochip_remove()
1965 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1967 struct irq_chip *irqchip = gpiochip->irq.chip;
1968 unsigned int offset;
1970 acpi_gpiochip_free_interrupts(gpiochip);
1972 if (irqchip && gpiochip->irq.parent_handler) {
1973 struct gpio_irq_chip *irq = &gpiochip->irq;
1976 for (i = 0; i < irq->num_parents; i++)
1977 irq_set_chained_handler_and_data(irq->parents[i],
1981 /* Remove all IRQ mappings and delete the domain */
1982 if (gpiochip->irq.domain) {
1985 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1986 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1989 irq = irq_find_mapping(gpiochip->irq.domain, offset);
1990 irq_dispose_mapping(irq);
1993 irq_domain_remove(gpiochip->irq.domain);
1997 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
1998 irqchip->irq_request_resources = NULL;
1999 irqchip->irq_release_resources = NULL;
2001 if (irqchip->irq_enable == gpiochip_irq_enable) {
2002 irqchip->irq_enable = gpiochip->irq.irq_enable;
2003 irqchip->irq_disable = gpiochip->irq.irq_disable;
2006 gpiochip->irq.irq_enable = NULL;
2007 gpiochip->irq.irq_disable = NULL;
2008 gpiochip->irq.chip = NULL;
2010 gpiochip_irqchip_free_valid_mask(gpiochip);
2014 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
2015 * @gpiochip: the gpiochip to add the irqchip to
2016 * @irqchip: the irqchip to add to the gpiochip
2017 * @first_irq: if not dynamically assigned, the base (first) IRQ to
2018 * allocate gpiochip irqs from
2019 * @handler: the irq handler to use (often a predefined irq core function)
2020 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
2021 * to have the core avoid setting up any default type in the hardware.
2022 * @threaded: whether this irqchip uses a nested thread handler
2023 * @lock_key: lockdep class for IRQ lock
2024 * @request_key: lockdep class for IRQ request
2026 * This function closely associates a certain irqchip with a certain
2027 * gpiochip, providing an irq domain to translate the local IRQs to
2028 * global irqs in the gpiolib core, and making sure that the gpiochip
2029 * is passed as chip data to all related functions. Driver callbacks
2030 * need to use gpiochip_get_data() to get their local state containers back
2031 * from the gpiochip passed as chip data. An irqdomain will be stored
2032 * in the gpiochip that shall be used by the driver to handle IRQ number
2033 * translation. The gpiochip will need to be initialized and registered
2034 * before calling this function.
2036 * This function will handle two cell:ed simple IRQs and assumes all
2037 * the pins on the gpiochip can generate a unique IRQ. Everything else
2038 * need to be open coded.
2040 int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
2041 struct irq_chip *irqchip,
2042 unsigned int first_irq,
2043 irq_flow_handler_t handler,
2046 struct lock_class_key *lock_key,
2047 struct lock_class_key *request_key)
2049 struct device_node *of_node;
2051 if (!gpiochip || !irqchip)
2054 if (!gpiochip->parent) {
2055 pr_err("missing gpiochip .dev parent pointer\n");
2058 gpiochip->irq.threaded = threaded;
2059 of_node = gpiochip->parent->of_node;
2060 #ifdef CONFIG_OF_GPIO
2062 * If the gpiochip has an assigned OF node this takes precedence
2063 * FIXME: get rid of this and use gpiochip->parent->of_node
2066 if (gpiochip->of_node)
2067 of_node = gpiochip->of_node;
2070 * Specifying a default trigger is a terrible idea if DT or ACPI is
2071 * used to configure the interrupts, as you may end-up with
2072 * conflicting triggers. Tell the user, and reset to NONE.
2074 if (WARN(of_node && type != IRQ_TYPE_NONE,
2075 "%pOF: Ignoring %d default trigger\n", of_node, type))
2076 type = IRQ_TYPE_NONE;
2077 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
2078 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
2079 "Ignoring %d default trigger\n", type);
2080 type = IRQ_TYPE_NONE;
2083 gpiochip->irq.chip = irqchip;
2084 gpiochip->irq.handler = handler;
2085 gpiochip->irq.default_type = type;
2086 gpiochip->to_irq = gpiochip_to_irq;
2087 gpiochip->irq.lock_key = lock_key;
2088 gpiochip->irq.request_key = request_key;
2089 gpiochip->irq.domain = irq_domain_add_simple(of_node,
2090 gpiochip->ngpio, first_irq,
2091 &gpiochip_domain_ops, gpiochip);
2092 if (!gpiochip->irq.domain) {
2093 gpiochip->irq.chip = NULL;
2097 gpiochip_set_irq_hooks(gpiochip);
2099 acpi_gpiochip_request_interrupts(gpiochip);
2103 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
2105 #else /* CONFIG_GPIOLIB_IRQCHIP */
2107 static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
2108 struct lock_class_key *lock_key,
2109 struct lock_class_key *request_key)
2114 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
2115 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
2119 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
2122 #endif /* CONFIG_GPIOLIB_IRQCHIP */
2125 * gpiochip_generic_request() - request the gpio function for a pin
2126 * @chip: the gpiochip owning the GPIO
2127 * @offset: the offset of the GPIO to request for GPIO function
2129 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
2131 return pinctrl_gpio_request(chip->gpiodev->base + offset);
2133 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2136 * gpiochip_generic_free() - free the gpio function from a pin
2137 * @chip: the gpiochip to request the gpio function for
2138 * @offset: the offset of the GPIO to free from GPIO function
2140 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
2142 pinctrl_gpio_free(chip->gpiodev->base + offset);
2144 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2147 * gpiochip_generic_config() - apply configuration for a pin
2148 * @chip: the gpiochip owning the GPIO
2149 * @offset: the offset of the GPIO to apply the configuration
2150 * @config: the configuration to be applied
2152 int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
2153 unsigned long config)
2155 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
2157 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2159 #ifdef CONFIG_PINCTRL
2162 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2163 * @chip: the gpiochip to add the range for
2164 * @pctldev: the pin controller to map to
2165 * @gpio_offset: the start offset in the current gpio_chip number space
2166 * @pin_group: name of the pin group inside the pin controller
2168 * Calling this function directly from a DeviceTree-supported
2169 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2170 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2171 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2173 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
2174 struct pinctrl_dev *pctldev,
2175 unsigned int gpio_offset, const char *pin_group)
2177 struct gpio_pin_range *pin_range;
2178 struct gpio_device *gdev = chip->gpiodev;
2181 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2183 chip_err(chip, "failed to allocate pin ranges\n");
2187 /* Use local offset as range ID */
2188 pin_range->range.id = gpio_offset;
2189 pin_range->range.gc = chip;
2190 pin_range->range.name = chip->label;
2191 pin_range->range.base = gdev->base + gpio_offset;
2192 pin_range->pctldev = pctldev;
2194 ret = pinctrl_get_group_pins(pctldev, pin_group,
2195 &pin_range->range.pins,
2196 &pin_range->range.npins);
2202 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2204 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2205 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2206 pinctrl_dev_get_devname(pctldev), pin_group);
2208 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2212 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2215 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2216 * @chip: the gpiochip to add the range for
2217 * @pinctl_name: the dev_name() of the pin controller to map to
2218 * @gpio_offset: the start offset in the current gpio_chip number space
2219 * @pin_offset: the start offset in the pin controller number space
2220 * @npins: the number of pins from the offset of each pin space (GPIO and
2221 * pin controller) to accumulate in this range
2224 * 0 on success, or a negative error-code on failure.
2226 * Calling this function directly from a DeviceTree-supported
2227 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2228 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2229 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2231 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
2232 unsigned int gpio_offset, unsigned int pin_offset,
2235 struct gpio_pin_range *pin_range;
2236 struct gpio_device *gdev = chip->gpiodev;
2239 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2241 chip_err(chip, "failed to allocate pin ranges\n");
2245 /* Use local offset as range ID */
2246 pin_range->range.id = gpio_offset;
2247 pin_range->range.gc = chip;
2248 pin_range->range.name = chip->label;
2249 pin_range->range.base = gdev->base + gpio_offset;
2250 pin_range->range.pin_base = pin_offset;
2251 pin_range->range.npins = npins;
2252 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2254 if (IS_ERR(pin_range->pctldev)) {
2255 ret = PTR_ERR(pin_range->pctldev);
2256 chip_err(chip, "could not create pin range\n");
2260 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2261 gpio_offset, gpio_offset + npins - 1,
2263 pin_offset, pin_offset + npins - 1);
2265 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2269 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2272 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2273 * @chip: the chip to remove all the mappings for
2275 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
2277 struct gpio_pin_range *pin_range, *tmp;
2278 struct gpio_device *gdev = chip->gpiodev;
2280 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2281 list_del(&pin_range->node);
2282 pinctrl_remove_gpio_range(pin_range->pctldev,
2287 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2289 #endif /* CONFIG_PINCTRL */
2291 /* These "optional" allocation calls help prevent drivers from stomping
2292 * on each other, and help provide better diagnostics in debugfs.
2293 * They're called even less than the "set direction" calls.
2295 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2297 struct gpio_chip *chip = desc->gdev->chip;
2299 unsigned long flags;
2302 spin_lock_irqsave(&gpio_lock, flags);
2304 /* NOTE: gpio_request() can be called in early boot,
2305 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2308 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2309 desc_set_label(desc, label ? : "?");
2316 if (chip->request) {
2317 /* chip->request may sleep */
2318 spin_unlock_irqrestore(&gpio_lock, flags);
2319 offset = gpio_chip_hwgpio(desc);
2320 if (gpiochip_line_is_valid(chip, offset))
2321 status = chip->request(chip, offset);
2324 spin_lock_irqsave(&gpio_lock, flags);
2327 desc_set_label(desc, NULL);
2328 clear_bit(FLAG_REQUESTED, &desc->flags);
2332 if (chip->get_direction) {
2333 /* chip->get_direction may sleep */
2334 spin_unlock_irqrestore(&gpio_lock, flags);
2335 gpiod_get_direction(desc);
2336 spin_lock_irqsave(&gpio_lock, flags);
2339 spin_unlock_irqrestore(&gpio_lock, flags);
2344 * This descriptor validation needs to be inserted verbatim into each
2345 * function taking a descriptor, so we need to use a preprocessor
2346 * macro to avoid endless duplication. If the desc is NULL it is an
2347 * optional GPIO and calls should just bail out.
2349 static int validate_desc(const struct gpio_desc *desc, const char *func)
2354 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2355 return PTR_ERR(desc);
2358 pr_warn("%s: invalid GPIO (no device)\n", func);
2361 if (!desc->gdev->chip) {
2362 dev_warn(&desc->gdev->dev,
2363 "%s: backing chip is gone\n", func);
2369 #define VALIDATE_DESC(desc) do { \
2370 int __valid = validate_desc(desc, __func__); \
2375 #define VALIDATE_DESC_VOID(desc) do { \
2376 int __valid = validate_desc(desc, __func__); \
2381 int gpiod_request(struct gpio_desc *desc, const char *label)
2383 int status = -EPROBE_DEFER;
2384 struct gpio_device *gdev;
2386 VALIDATE_DESC(desc);
2389 if (try_module_get(gdev->owner)) {
2390 status = gpiod_request_commit(desc, label);
2392 module_put(gdev->owner);
2394 get_device(&gdev->dev);
2398 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2403 static bool gpiod_free_commit(struct gpio_desc *desc)
2406 unsigned long flags;
2407 struct gpio_chip *chip;
2411 gpiod_unexport(desc);
2413 spin_lock_irqsave(&gpio_lock, flags);
2415 chip = desc->gdev->chip;
2416 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2418 spin_unlock_irqrestore(&gpio_lock, flags);
2419 might_sleep_if(chip->can_sleep);
2420 chip->free(chip, gpio_chip_hwgpio(desc));
2421 spin_lock_irqsave(&gpio_lock, flags);
2423 desc_set_label(desc, NULL);
2424 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2425 clear_bit(FLAG_REQUESTED, &desc->flags);
2426 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2427 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2428 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2432 spin_unlock_irqrestore(&gpio_lock, flags);
2436 void gpiod_free(struct gpio_desc *desc)
2438 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2439 module_put(desc->gdev->owner);
2440 put_device(&desc->gdev->dev);
2442 WARN_ON(extra_checks);
2447 * gpiochip_is_requested - return string iff signal was requested
2448 * @chip: controller managing the signal
2449 * @offset: of signal within controller's 0..(ngpio - 1) range
2451 * Returns NULL if the GPIO is not currently requested, else a string.
2452 * The string returned is the label passed to gpio_request(); if none has been
2453 * passed it is a meaningless, non-NULL constant.
2455 * This function is for use by GPIO controller drivers. The label can
2456 * help with diagnostics, and knowing that the signal is used as a GPIO
2457 * can help avoid accidentally multiplexing it to another controller.
2459 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2461 struct gpio_desc *desc;
2463 if (offset >= chip->ngpio)
2466 desc = &chip->gpiodev->descs[offset];
2468 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2472 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2475 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2477 * @hwnum: hardware number of the GPIO for which to request the descriptor
2478 * @label: label for the GPIO
2480 * Function allows GPIO chip drivers to request and use their own GPIO
2481 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2482 * function will not increase reference count of the GPIO chip module. This
2483 * allows the GPIO chip module to be unloaded as needed (we assume that the
2484 * GPIO chip driver handles freeing the GPIOs it has requested).
2487 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2490 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2493 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2497 chip_err(chip, "failed to get GPIO descriptor\n");
2501 err = gpiod_request_commit(desc, label);
2503 return ERR_PTR(err);
2507 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2510 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2511 * @desc: GPIO descriptor to free
2513 * Function frees the given GPIO requested previously with
2514 * gpiochip_request_own_desc().
2516 void gpiochip_free_own_desc(struct gpio_desc *desc)
2519 gpiod_free_commit(desc);
2521 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2524 * Drivers MUST set GPIO direction before making get/set calls. In
2525 * some cases this is done in early boot, before IRQs are enabled.
2527 * As a rule these aren't called more than once (except for drivers
2528 * using the open-drain emulation idiom) so these are natural places
2529 * to accumulate extra debugging checks. Note that we can't (yet)
2530 * rely on gpio_request() having been called beforehand.
2534 * gpiod_direction_input - set the GPIO direction to input
2535 * @desc: GPIO to set to input
2537 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2538 * be called safely on it.
2540 * Return 0 in case of success, else an error code.
2542 int gpiod_direction_input(struct gpio_desc *desc)
2544 struct gpio_chip *chip;
2547 VALIDATE_DESC(desc);
2548 chip = desc->gdev->chip;
2551 * It is legal to have no .get() and .direction_input() specified if
2552 * the chip is output-only, but you can't specify .direction_input()
2553 * and not support the .get() operation, that doesn't make sense.
2555 if (!chip->get && chip->direction_input) {
2557 "%s: missing get() but have direction_input()\n",
2563 * If we have a .direction_input() callback, things are simple,
2564 * just call it. Else we are some input-only chip so try to check the
2565 * direction (if .get_direction() is supported) else we silently
2566 * assume we are in input mode after this.
2568 if (chip->direction_input) {
2569 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2570 } else if (chip->get_direction &&
2571 (chip->get_direction(chip, gpio_chip_hwgpio(desc)) != 1)) {
2573 "%s: missing direction_input() operation and line is output\n",
2578 clear_bit(FLAG_IS_OUT, &desc->flags);
2580 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2584 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2586 static int gpio_set_drive_single_ended(struct gpio_chip *gc, unsigned offset,
2587 enum pin_config_param mode)
2589 unsigned long config = { PIN_CONF_PACKED(mode, 0) };
2591 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2594 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2596 struct gpio_chip *gc = desc->gdev->chip;
2601 * It's OK not to specify .direction_output() if the gpiochip is
2602 * output-only, but if there is then not even a .set() operation it
2603 * is pretty tricky to drive the output line.
2605 if (!gc->set && !gc->direction_output) {
2607 "%s: missing set() and direction_output() operations\n",
2612 if (gc->direction_output) {
2613 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2615 /* Check that we are in output mode if we can */
2616 if (gc->get_direction &&
2617 gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
2619 "%s: missing direction_output() operation\n",
2624 * If we can't actively set the direction, we are some
2625 * output-only chip, so just drive the output as desired.
2627 gc->set(gc, gpio_chip_hwgpio(desc), val);
2631 set_bit(FLAG_IS_OUT, &desc->flags);
2632 trace_gpio_value(desc_to_gpio(desc), 0, val);
2633 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2638 * gpiod_direction_output_raw - set the GPIO direction to output
2639 * @desc: GPIO to set to output
2640 * @value: initial output value of the GPIO
2642 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2643 * be called safely on it. The initial value of the output must be specified
2644 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2646 * Return 0 in case of success, else an error code.
2648 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2650 VALIDATE_DESC(desc);
2651 return gpiod_direction_output_raw_commit(desc, value);
2653 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2656 * gpiod_direction_output - set the GPIO direction to output
2657 * @desc: GPIO to set to output
2658 * @value: initial output value of the GPIO
2660 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2661 * be called safely on it. The initial value of the output must be specified
2662 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2665 * Return 0 in case of success, else an error code.
2667 int gpiod_direction_output(struct gpio_desc *desc, int value)
2669 struct gpio_chip *gc;
2672 VALIDATE_DESC(desc);
2673 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2678 /* GPIOs used for enabled IRQs shall not be set as output */
2679 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
2680 test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
2682 "%s: tried to set a GPIO tied to an IRQ as output\n",
2687 gc = desc->gdev->chip;
2688 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2689 /* First see if we can enable open drain in hardware */
2690 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2691 PIN_CONFIG_DRIVE_OPEN_DRAIN);
2693 goto set_output_value;
2694 /* Emulate open drain by not actively driving the line high */
2696 return gpiod_direction_input(desc);
2698 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2699 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2700 PIN_CONFIG_DRIVE_OPEN_SOURCE);
2702 goto set_output_value;
2703 /* Emulate open source by not actively driving the line low */
2705 return gpiod_direction_input(desc);
2707 gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2708 PIN_CONFIG_DRIVE_PUSH_PULL);
2712 return gpiod_direction_output_raw_commit(desc, value);
2714 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2717 * gpiod_set_debounce - sets @debounce time for a GPIO
2718 * @desc: descriptor of the GPIO for which to set debounce time
2719 * @debounce: debounce time in microseconds
2722 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2725 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2727 struct gpio_chip *chip;
2728 unsigned long config;
2730 VALIDATE_DESC(desc);
2731 chip = desc->gdev->chip;
2732 if (!chip->set || !chip->set_config) {
2734 "%s: missing set() or set_config() operations\n",
2739 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2740 return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
2742 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2745 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2746 * @desc: descriptor of the GPIO for which to configure persistence
2747 * @transitory: True to lose state on suspend or reset, false for persistence
2750 * 0 on success, otherwise a negative error code.
2752 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2754 struct gpio_chip *chip;
2755 unsigned long packed;
2759 VALIDATE_DESC(desc);
2761 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2762 * persistence state.
2765 set_bit(FLAG_TRANSITORY, &desc->flags);
2767 clear_bit(FLAG_TRANSITORY, &desc->flags);
2769 /* If the driver supports it, set the persistence state now */
2770 chip = desc->gdev->chip;
2771 if (!chip->set_config)
2774 packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
2776 gpio = gpio_chip_hwgpio(desc);
2777 rc = chip->set_config(chip, gpio, packed);
2778 if (rc == -ENOTSUPP) {
2779 dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
2786 EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2789 * gpiod_is_active_low - test whether a GPIO is active-low or not
2790 * @desc: the gpio descriptor to test
2792 * Returns 1 if the GPIO is active-low, 0 otherwise.
2794 int gpiod_is_active_low(const struct gpio_desc *desc)
2796 VALIDATE_DESC(desc);
2797 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2799 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2801 /* I/O calls are only valid after configuration completed; the relevant
2802 * "is this a valid GPIO" error checks should already have been done.
2804 * "Get" operations are often inlinable as reading a pin value register,
2805 * and masking the relevant bit in that register.
2807 * When "set" operations are inlinable, they involve writing that mask to
2808 * one register to set a low value, or a different register to set it high.
2809 * Otherwise locking is needed, so there may be little value to inlining.
2811 *------------------------------------------------------------------------
2813 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2814 * have requested the GPIO. That can include implicit requesting by
2815 * a direction setting call. Marking a gpio as requested locks its chip
2816 * in memory, guaranteeing that these table lookups need no more locking
2817 * and that gpiochip_remove() will fail.
2819 * REVISIT when debugging, consider adding some instrumentation to ensure
2820 * that the GPIO was actually requested.
2823 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2825 struct gpio_chip *chip;
2829 chip = desc->gdev->chip;
2830 offset = gpio_chip_hwgpio(desc);
2831 value = chip->get ? chip->get(chip, offset) : -EIO;
2832 value = value < 0 ? value : !!value;
2833 trace_gpio_value(desc_to_gpio(desc), 1, value);
2837 static int gpio_chip_get_multiple(struct gpio_chip *chip,
2838 unsigned long *mask, unsigned long *bits)
2840 if (chip->get_multiple) {
2841 return chip->get_multiple(chip, mask, bits);
2842 } else if (chip->get) {
2845 for_each_set_bit(i, mask, chip->ngpio) {
2846 value = chip->get(chip, i);
2849 __assign_bit(i, bits, value);
2856 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2857 unsigned int array_size,
2858 struct gpio_desc **desc_array,
2859 struct gpio_array *array_info,
2860 unsigned long *value_bitmap)
2865 * Validate array_info against desc_array and its size.
2866 * It should immediately follow desc_array if both
2867 * have been obtained from the same gpiod_get_array() call.
2869 if (array_info && array_info->desc == desc_array &&
2870 array_size <= array_info->size &&
2871 (void *)array_info == desc_array + array_info->size) {
2873 WARN_ON(array_info->chip->can_sleep);
2875 err = gpio_chip_get_multiple(array_info->chip,
2876 array_info->get_mask,
2881 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2882 bitmap_xor(value_bitmap, value_bitmap,
2883 array_info->invert_mask, array_size);
2885 if (bitmap_full(array_info->get_mask, array_size))
2888 i = find_first_zero_bit(array_info->get_mask, array_size);
2893 while (i < array_size) {
2894 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2895 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
2896 unsigned long *mask, *bits;
2899 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
2902 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
2904 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
2909 bits = mask + BITS_TO_LONGS(chip->ngpio);
2910 bitmap_zero(mask, chip->ngpio);
2913 WARN_ON(chip->can_sleep);
2915 /* collect all inputs belonging to the same chip */
2918 const struct gpio_desc *desc = desc_array[i];
2919 int hwgpio = gpio_chip_hwgpio(desc);
2921 __set_bit(hwgpio, mask);
2925 i = find_next_zero_bit(array_info->get_mask,
2927 } while ((i < array_size) &&
2928 (desc_array[i]->gdev->chip == chip));
2930 ret = gpio_chip_get_multiple(chip, mask, bits);
2932 if (mask != fastpath)
2937 for (j = first; j < i; ) {
2938 const struct gpio_desc *desc = desc_array[j];
2939 int hwgpio = gpio_chip_hwgpio(desc);
2940 int value = test_bit(hwgpio, bits);
2942 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2944 __assign_bit(j, value_bitmap, value);
2945 trace_gpio_value(desc_to_gpio(desc), 1, value);
2949 j = find_next_zero_bit(array_info->get_mask, i,
2953 if (mask != fastpath)
2960 * gpiod_get_raw_value() - return a gpio's raw value
2961 * @desc: gpio whose value will be returned
2963 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2964 * its ACTIVE_LOW status, or negative errno on failure.
2966 * This function should be called from contexts where we cannot sleep, and will
2967 * complain if the GPIO chip functions potentially sleep.
2969 int gpiod_get_raw_value(const struct gpio_desc *desc)
2971 VALIDATE_DESC(desc);
2972 /* Should be using gpio_get_value_cansleep() */
2973 WARN_ON(desc->gdev->chip->can_sleep);
2974 return gpiod_get_raw_value_commit(desc);
2976 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2979 * gpiod_get_value() - return a gpio's value
2980 * @desc: gpio whose value will be returned
2982 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2983 * account, or negative errno on failure.
2985 * This function should be called from contexts where we cannot sleep, and will
2986 * complain if the GPIO chip functions potentially sleep.
2988 int gpiod_get_value(const struct gpio_desc *desc)
2992 VALIDATE_DESC(desc);
2993 /* Should be using gpio_get_value_cansleep() */
2994 WARN_ON(desc->gdev->chip->can_sleep);
2996 value = gpiod_get_raw_value_commit(desc);
3000 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3005 EXPORT_SYMBOL_GPL(gpiod_get_value);
3008 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
3009 * @array_size: number of elements in the descriptor array / value bitmap
3010 * @desc_array: array of GPIO descriptors whose values will be read
3011 * @array_info: information on applicability of fast bitmap processing path
3012 * @value_bitmap: bitmap to store the read values
3014 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3015 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3016 * else an error code.
3018 * This function should be called from contexts where we cannot sleep,
3019 * and it will complain if the GPIO chip functions potentially sleep.
3021 int gpiod_get_raw_array_value(unsigned int array_size,
3022 struct gpio_desc **desc_array,
3023 struct gpio_array *array_info,
3024 unsigned long *value_bitmap)
3028 return gpiod_get_array_value_complex(true, false, array_size,
3029 desc_array, array_info,
3032 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
3035 * gpiod_get_array_value() - read values from an array of GPIOs
3036 * @array_size: number of elements in the descriptor array / value bitmap
3037 * @desc_array: array of GPIO descriptors whose values will be read
3038 * @array_info: information on applicability of fast bitmap processing path
3039 * @value_bitmap: bitmap to store the read values
3041 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3042 * into account. Return 0 in case of success, else an error code.
3044 * This function should be called from contexts where we cannot sleep,
3045 * and it will complain if the GPIO chip functions potentially sleep.
3047 int gpiod_get_array_value(unsigned int array_size,
3048 struct gpio_desc **desc_array,
3049 struct gpio_array *array_info,
3050 unsigned long *value_bitmap)
3054 return gpiod_get_array_value_complex(false, false, array_size,
3055 desc_array, array_info,
3058 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
3061 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
3062 * @desc: gpio descriptor whose state need to be set.
3063 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3065 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
3068 struct gpio_chip *chip = desc->gdev->chip;
3069 int offset = gpio_chip_hwgpio(desc);
3072 err = chip->direction_input(chip, offset);
3074 clear_bit(FLAG_IS_OUT, &desc->flags);
3076 err = chip->direction_output(chip, offset, 0);
3078 set_bit(FLAG_IS_OUT, &desc->flags);
3080 trace_gpio_direction(desc_to_gpio(desc), value, err);
3083 "%s: Error in set_value for open drain err %d\n",
3088 * _gpio_set_open_source_value() - Set the open source gpio's value.
3089 * @desc: gpio descriptor whose state need to be set.
3090 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3092 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
3095 struct gpio_chip *chip = desc->gdev->chip;
3096 int offset = gpio_chip_hwgpio(desc);
3099 err = chip->direction_output(chip, offset, 1);
3101 set_bit(FLAG_IS_OUT, &desc->flags);
3103 err = chip->direction_input(chip, offset);
3105 clear_bit(FLAG_IS_OUT, &desc->flags);
3107 trace_gpio_direction(desc_to_gpio(desc), !value, err);
3110 "%s: Error in set_value for open source err %d\n",
3114 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
3116 struct gpio_chip *chip;
3118 chip = desc->gdev->chip;
3119 trace_gpio_value(desc_to_gpio(desc), 0, value);
3120 chip->set(chip, gpio_chip_hwgpio(desc), value);
3124 * set multiple outputs on the same chip;
3125 * use the chip's set_multiple function if available;
3126 * otherwise set the outputs sequentially;
3127 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3128 * defines which outputs are to be changed
3129 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3130 * defines the values the outputs specified by mask are to be set to
3132 static void gpio_chip_set_multiple(struct gpio_chip *chip,
3133 unsigned long *mask, unsigned long *bits)
3135 if (chip->set_multiple) {
3136 chip->set_multiple(chip, mask, bits);
3140 /* set outputs if the corresponding mask bit is set */
3141 for_each_set_bit(i, mask, chip->ngpio)
3142 chip->set(chip, i, test_bit(i, bits));
3146 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3147 unsigned int array_size,
3148 struct gpio_desc **desc_array,
3149 struct gpio_array *array_info,
3150 unsigned long *value_bitmap)
3155 * Validate array_info against desc_array and its size.
3156 * It should immediately follow desc_array if both
3157 * have been obtained from the same gpiod_get_array() call.
3159 if (array_info && array_info->desc == desc_array &&
3160 array_size <= array_info->size &&
3161 (void *)array_info == desc_array + array_info->size) {
3163 WARN_ON(array_info->chip->can_sleep);
3165 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3166 bitmap_xor(value_bitmap, value_bitmap,
3167 array_info->invert_mask, array_size);
3169 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
3172 if (bitmap_full(array_info->set_mask, array_size))
3175 i = find_first_zero_bit(array_info->set_mask, array_size);
3180 while (i < array_size) {
3181 struct gpio_chip *chip = desc_array[i]->gdev->chip;
3182 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
3183 unsigned long *mask, *bits;
3186 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
3189 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
3191 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
3196 bits = mask + BITS_TO_LONGS(chip->ngpio);
3197 bitmap_zero(mask, chip->ngpio);
3200 WARN_ON(chip->can_sleep);
3203 struct gpio_desc *desc = desc_array[i];
3204 int hwgpio = gpio_chip_hwgpio(desc);
3205 int value = test_bit(i, value_bitmap);
3208 * Pins applicable for fast input but not for
3209 * fast output processing may have been already
3210 * inverted inside the fast path, skip them.
3212 if (!raw && !(array_info &&
3213 test_bit(i, array_info->invert_mask)) &&
3214 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3216 trace_gpio_value(desc_to_gpio(desc), 0, value);
3218 * collect all normal outputs belonging to the same chip
3219 * open drain and open source outputs are set individually
3221 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3222 gpio_set_open_drain_value_commit(desc, value);
3223 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3224 gpio_set_open_source_value_commit(desc, value);
3226 __set_bit(hwgpio, mask);
3228 __set_bit(hwgpio, bits);
3230 __clear_bit(hwgpio, bits);
3236 i = find_next_zero_bit(array_info->set_mask,
3238 } while ((i < array_size) &&
3239 (desc_array[i]->gdev->chip == chip));
3240 /* push collected bits to outputs */
3242 gpio_chip_set_multiple(chip, mask, bits);
3244 if (mask != fastpath)
3251 * gpiod_set_raw_value() - assign a gpio's raw value
3252 * @desc: gpio whose value will be assigned
3253 * @value: value to assign
3255 * Set the raw value of the GPIO, i.e. the value of its physical line without
3256 * regard for its ACTIVE_LOW status.
3258 * This function should be called from contexts where we cannot sleep, and will
3259 * complain if the GPIO chip functions potentially sleep.
3261 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3263 VALIDATE_DESC_VOID(desc);
3264 /* Should be using gpiod_set_value_cansleep() */
3265 WARN_ON(desc->gdev->chip->can_sleep);
3266 gpiod_set_raw_value_commit(desc, value);
3268 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3271 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3272 * @desc: the descriptor to set the value on
3273 * @value: value to set
3275 * This sets the value of a GPIO line backing a descriptor, applying
3276 * different semantic quirks like active low and open drain/source
3279 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3281 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3283 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3284 gpio_set_open_drain_value_commit(desc, value);
3285 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3286 gpio_set_open_source_value_commit(desc, value);
3288 gpiod_set_raw_value_commit(desc, value);
3292 * gpiod_set_value() - assign a gpio's value
3293 * @desc: gpio whose value will be assigned
3294 * @value: value to assign
3296 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3297 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3299 * This function should be called from contexts where we cannot sleep, and will
3300 * complain if the GPIO chip functions potentially sleep.
3302 void gpiod_set_value(struct gpio_desc *desc, int value)
3304 VALIDATE_DESC_VOID(desc);
3305 WARN_ON(desc->gdev->chip->can_sleep);
3306 gpiod_set_value_nocheck(desc, value);
3308 EXPORT_SYMBOL_GPL(gpiod_set_value);
3311 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3312 * @array_size: number of elements in the descriptor array / value bitmap
3313 * @desc_array: array of GPIO descriptors whose values will be assigned
3314 * @array_info: information on applicability of fast bitmap processing path
3315 * @value_bitmap: bitmap of values to assign
3317 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3318 * without regard for their ACTIVE_LOW status.
3320 * This function should be called from contexts where we cannot sleep, and will
3321 * complain if the GPIO chip functions potentially sleep.
3323 int gpiod_set_raw_array_value(unsigned int array_size,
3324 struct gpio_desc **desc_array,
3325 struct gpio_array *array_info,
3326 unsigned long *value_bitmap)
3330 return gpiod_set_array_value_complex(true, false, array_size,
3331 desc_array, array_info, value_bitmap);
3333 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3336 * gpiod_set_array_value() - assign values to an array of GPIOs
3337 * @array_size: number of elements in the descriptor array / value bitmap
3338 * @desc_array: array of GPIO descriptors whose values will be assigned
3339 * @array_info: information on applicability of fast bitmap processing path
3340 * @value_bitmap: bitmap of values to assign
3342 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3345 * This function should be called from contexts where we cannot sleep, and will
3346 * complain if the GPIO chip functions potentially sleep.
3348 int gpiod_set_array_value(unsigned int array_size,
3349 struct gpio_desc **desc_array,
3350 struct gpio_array *array_info,
3351 unsigned long *value_bitmap)
3355 return gpiod_set_array_value_complex(false, false, array_size,
3356 desc_array, array_info,
3359 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3362 * gpiod_cansleep() - report whether gpio value access may sleep
3363 * @desc: gpio to check
3366 int gpiod_cansleep(const struct gpio_desc *desc)
3368 VALIDATE_DESC(desc);
3369 return desc->gdev->chip->can_sleep;
3371 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3374 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3375 * @desc: gpio to set the consumer name on
3376 * @name: the new consumer name
3378 void gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3380 VALIDATE_DESC_VOID(desc);
3381 /* Just overwrite whatever the previous name was */
3384 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3387 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3388 * @desc: gpio whose IRQ will be returned (already requested)
3390 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3393 int gpiod_to_irq(const struct gpio_desc *desc)
3395 struct gpio_chip *chip;
3399 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3400 * requires this function to not return zero on an invalid descriptor
3401 * but rather a negative error number.
3403 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3406 chip = desc->gdev->chip;
3407 offset = gpio_chip_hwgpio(desc);
3409 int retirq = chip->to_irq(chip, offset);
3411 /* Zero means NO_IRQ */
3419 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3422 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3423 * @chip: the chip the GPIO to lock belongs to
3424 * @offset: the offset of the GPIO to lock as IRQ
3426 * This is used directly by GPIO drivers that want to lock down
3427 * a certain GPIO line to be used for IRQs.
3429 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
3431 struct gpio_desc *desc;
3433 desc = gpiochip_get_desc(chip, offset);
3435 return PTR_ERR(desc);
3438 * If it's fast: flush the direction setting if something changed
3441 if (!chip->can_sleep && chip->get_direction) {
3442 int dir = gpiod_get_direction(desc);
3445 chip_err(chip, "%s: cannot get GPIO direction\n",
3451 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
3453 "%s: tried to flag a GPIO set as output for IRQ\n",
3458 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3459 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3462 * If the consumer has not set up a label (such as when the
3463 * IRQ is referenced from .to_irq()) we set up a label here
3464 * so it is clear this is used as an interrupt.
3467 desc_set_label(desc, "interrupt");
3471 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3474 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3475 * @chip: the chip the GPIO to lock belongs to
3476 * @offset: the offset of the GPIO to lock as IRQ
3478 * This is used directly by GPIO drivers that want to indicate
3479 * that a certain GPIO is no longer used exclusively for IRQ.
3481 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
3483 struct gpio_desc *desc;
3485 desc = gpiochip_get_desc(chip, offset);
3489 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3490 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3492 /* If we only had this marking, erase it */
3493 if (desc->label && !strcmp(desc->label, "interrupt"))
3494 desc_set_label(desc, NULL);
3496 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3498 void gpiochip_disable_irq(struct gpio_chip *chip, unsigned int offset)
3500 struct gpio_desc *desc = gpiochip_get_desc(chip, offset);
3502 if (!IS_ERR(desc) &&
3503 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3504 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3506 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3508 void gpiochip_enable_irq(struct gpio_chip *chip, unsigned int offset)
3510 struct gpio_desc *desc = gpiochip_get_desc(chip, offset);
3512 if (!IS_ERR(desc) &&
3513 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3514 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags));
3515 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3518 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3520 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
3522 if (offset >= chip->ngpio)
3525 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
3527 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3529 int gpiochip_reqres_irq(struct gpio_chip *chip, unsigned int offset)
3533 if (!try_module_get(chip->gpiodev->owner))
3536 ret = gpiochip_lock_as_irq(chip, offset);
3538 chip_err(chip, "unable to lock HW IRQ %u for IRQ\n", offset);
3539 module_put(chip->gpiodev->owner);
3544 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3546 void gpiochip_relres_irq(struct gpio_chip *chip, unsigned int offset)
3548 gpiochip_unlock_as_irq(chip, offset);
3549 module_put(chip->gpiodev->owner);
3551 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3553 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
3555 if (offset >= chip->ngpio)
3558 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
3560 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3562 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
3564 if (offset >= chip->ngpio)
3567 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
3569 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3571 bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
3573 if (offset >= chip->ngpio)
3576 return !test_bit(FLAG_TRANSITORY, &chip->gpiodev->descs[offset].flags);
3578 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3581 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3582 * @desc: gpio whose value will be returned
3584 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3585 * its ACTIVE_LOW status, or negative errno on failure.
3587 * This function is to be called from contexts that can sleep.
3589 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3591 might_sleep_if(extra_checks);
3592 VALIDATE_DESC(desc);
3593 return gpiod_get_raw_value_commit(desc);
3595 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3598 * gpiod_get_value_cansleep() - return a gpio's value
3599 * @desc: gpio whose value will be returned
3601 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3602 * account, or negative errno on failure.
3604 * This function is to be called from contexts that can sleep.
3606 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3610 might_sleep_if(extra_checks);
3611 VALIDATE_DESC(desc);
3612 value = gpiod_get_raw_value_commit(desc);
3616 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3621 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3624 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3625 * @array_size: number of elements in the descriptor array / value bitmap
3626 * @desc_array: array of GPIO descriptors whose values will be read
3627 * @array_info: information on applicability of fast bitmap processing path
3628 * @value_bitmap: bitmap to store the read values
3630 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3631 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3632 * else an error code.
3634 * This function is to be called from contexts that can sleep.
3636 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3637 struct gpio_desc **desc_array,
3638 struct gpio_array *array_info,
3639 unsigned long *value_bitmap)
3641 might_sleep_if(extra_checks);
3644 return gpiod_get_array_value_complex(true, true, array_size,
3645 desc_array, array_info,
3648 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3651 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3652 * @array_size: number of elements in the descriptor array / value bitmap
3653 * @desc_array: array of GPIO descriptors whose values will be read
3654 * @array_info: information on applicability of fast bitmap processing path
3655 * @value_bitmap: bitmap to store the read values
3657 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3658 * into account. Return 0 in case of success, else an error code.
3660 * This function is to be called from contexts that can sleep.
3662 int gpiod_get_array_value_cansleep(unsigned int array_size,
3663 struct gpio_desc **desc_array,
3664 struct gpio_array *array_info,
3665 unsigned long *value_bitmap)
3667 might_sleep_if(extra_checks);
3670 return gpiod_get_array_value_complex(false, true, array_size,
3671 desc_array, array_info,
3674 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3677 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3678 * @desc: gpio whose value will be assigned
3679 * @value: value to assign
3681 * Set the raw value of the GPIO, i.e. the value of its physical line without
3682 * regard for its ACTIVE_LOW status.
3684 * This function is to be called from contexts that can sleep.
3686 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3688 might_sleep_if(extra_checks);
3689 VALIDATE_DESC_VOID(desc);
3690 gpiod_set_raw_value_commit(desc, value);
3692 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3695 * gpiod_set_value_cansleep() - assign a gpio's value
3696 * @desc: gpio whose value will be assigned
3697 * @value: value to assign
3699 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3702 * This function is to be called from contexts that can sleep.
3704 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3706 might_sleep_if(extra_checks);
3707 VALIDATE_DESC_VOID(desc);
3708 gpiod_set_value_nocheck(desc, value);
3710 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3713 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3714 * @array_size: number of elements in the descriptor array / value bitmap
3715 * @desc_array: array of GPIO descriptors whose values will be assigned
3716 * @array_info: information on applicability of fast bitmap processing path
3717 * @value_bitmap: bitmap of values to assign
3719 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3720 * without regard for their ACTIVE_LOW status.
3722 * This function is to be called from contexts that can sleep.
3724 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3725 struct gpio_desc **desc_array,
3726 struct gpio_array *array_info,
3727 unsigned long *value_bitmap)
3729 might_sleep_if(extra_checks);
3732 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3733 array_info, value_bitmap);
3735 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3738 * gpiod_add_lookup_tables() - register GPIO device consumers
3739 * @tables: list of tables of consumers to register
3740 * @n: number of tables in the list
3742 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3746 mutex_lock(&gpio_lookup_lock);
3748 for (i = 0; i < n; i++)
3749 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3751 mutex_unlock(&gpio_lookup_lock);
3755 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3756 * @array_size: number of elements in the descriptor array / value bitmap
3757 * @desc_array: array of GPIO descriptors whose values will be assigned
3758 * @array_info: information on applicability of fast bitmap processing path
3759 * @value_bitmap: bitmap of values to assign
3761 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3764 * This function is to be called from contexts that can sleep.
3766 int gpiod_set_array_value_cansleep(unsigned int array_size,
3767 struct gpio_desc **desc_array,
3768 struct gpio_array *array_info,
3769 unsigned long *value_bitmap)
3771 might_sleep_if(extra_checks);
3774 return gpiod_set_array_value_complex(false, true, array_size,
3775 desc_array, array_info,
3778 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3781 * gpiod_add_lookup_table() - register GPIO device consumers
3782 * @table: table of consumers to register
3784 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3786 mutex_lock(&gpio_lookup_lock);
3788 list_add_tail(&table->list, &gpio_lookup_list);
3790 mutex_unlock(&gpio_lookup_lock);
3792 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3795 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3796 * @table: table of consumers to unregister
3798 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3800 mutex_lock(&gpio_lookup_lock);
3802 list_del(&table->list);
3804 mutex_unlock(&gpio_lookup_lock);
3806 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3809 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
3810 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
3812 void gpiod_add_hogs(struct gpiod_hog *hogs)
3814 struct gpio_chip *chip;
3815 struct gpiod_hog *hog;
3817 mutex_lock(&gpio_machine_hogs_mutex);
3819 for (hog = &hogs[0]; hog->chip_label; hog++) {
3820 list_add_tail(&hog->list, &gpio_machine_hogs);
3823 * The chip may have been registered earlier, so check if it
3824 * exists and, if so, try to hog the line now.
3826 chip = find_chip_by_name(hog->chip_label);
3828 gpiochip_machine_hog(chip, hog);
3831 mutex_unlock(&gpio_machine_hogs_mutex);
3833 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
3835 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3837 const char *dev_id = dev ? dev_name(dev) : NULL;
3838 struct gpiod_lookup_table *table;
3840 mutex_lock(&gpio_lookup_lock);
3842 list_for_each_entry(table, &gpio_lookup_list, list) {
3843 if (table->dev_id && dev_id) {
3845 * Valid strings on both ends, must be identical to have
3848 if (!strcmp(table->dev_id, dev_id))
3852 * One of the pointers is NULL, so both must be to have
3855 if (dev_id == table->dev_id)
3862 mutex_unlock(&gpio_lookup_lock);
3866 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3868 enum gpio_lookup_flags *flags)
3870 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3871 struct gpiod_lookup_table *table;
3872 struct gpiod_lookup *p;
3874 table = gpiod_find_lookup_table(dev);
3878 for (p = &table->table[0]; p->chip_label; p++) {
3879 struct gpio_chip *chip;
3881 /* idx must always match exactly */
3885 /* If the lookup entry has a con_id, require exact match */
3886 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3889 chip = find_chip_by_name(p->chip_label);
3893 * As the lookup table indicates a chip with
3894 * p->chip_label should exist, assume it may
3895 * still appear later and let the interested
3896 * consumer be probed again or let the Deferred
3897 * Probe infrastructure handle the error.
3899 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
3901 return ERR_PTR(-EPROBE_DEFER);
3904 if (chip->ngpio <= p->chip_hwnum) {
3906 "requested GPIO %d is out of range [0..%d] for chip %s\n",
3907 idx, chip->ngpio, chip->label);
3908 return ERR_PTR(-EINVAL);
3911 desc = gpiochip_get_desc(chip, p->chip_hwnum);
3920 static int dt_gpio_count(struct device *dev, const char *con_id)
3926 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3928 snprintf(propname, sizeof(propname), "%s-%s",
3929 con_id, gpio_suffixes[i]);
3931 snprintf(propname, sizeof(propname), "%s",
3934 ret = of_gpio_named_count(dev->of_node, propname);
3938 return ret ? ret : -ENOENT;
3941 static int platform_gpio_count(struct device *dev, const char *con_id)
3943 struct gpiod_lookup_table *table;
3944 struct gpiod_lookup *p;
3945 unsigned int count = 0;
3947 table = gpiod_find_lookup_table(dev);
3951 for (p = &table->table[0]; p->chip_label; p++) {
3952 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3953 (!con_id && !p->con_id))
3963 * gpiod_count - return the number of GPIOs associated with a device / function
3964 * or -ENOENT if no GPIO has been assigned to the requested function
3965 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3966 * @con_id: function within the GPIO consumer
3968 int gpiod_count(struct device *dev, const char *con_id)
3970 int count = -ENOENT;
3972 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
3973 count = dt_gpio_count(dev, con_id);
3974 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
3975 count = acpi_gpio_count(dev, con_id);
3978 count = platform_gpio_count(dev, con_id);
3982 EXPORT_SYMBOL_GPL(gpiod_count);
3985 * gpiod_get - obtain a 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 * Return the GPIO descriptor corresponding to the function con_id of device
3991 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3992 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3994 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3995 enum gpiod_flags flags)
3997 return gpiod_get_index(dev, con_id, 0, flags);
3999 EXPORT_SYMBOL_GPL(gpiod_get);
4002 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
4003 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4004 * @con_id: function within the GPIO consumer
4005 * @flags: optional GPIO initialization flags
4007 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
4008 * the requested function it will return NULL. This is convenient for drivers
4009 * that need to handle optional GPIOs.
4011 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
4013 enum gpiod_flags flags)
4015 return gpiod_get_index_optional(dev, con_id, 0, flags);
4017 EXPORT_SYMBOL_GPL(gpiod_get_optional);
4021 * gpiod_configure_flags - helper function to configure a given GPIO
4022 * @desc: gpio whose value will be assigned
4023 * @con_id: function within the GPIO consumer
4024 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
4026 * @dflags: gpiod_flags - optional GPIO initialization flags
4028 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
4029 * requested function and/or index, or another IS_ERR() code if an error
4030 * occurred while trying to acquire the GPIO.
4032 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
4033 unsigned long lflags, enum gpiod_flags dflags)
4037 if (lflags & GPIO_ACTIVE_LOW)
4038 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
4040 if (lflags & GPIO_OPEN_DRAIN)
4041 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4042 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
4044 * This enforces open drain mode from the consumer side.
4045 * This is necessary for some busses like I2C, but the lookup
4046 * should *REALLY* have specified them as open drain in the
4047 * first place, so print a little warning here.
4049 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4051 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
4054 if (lflags & GPIO_OPEN_SOURCE)
4055 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
4057 status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
4061 /* No particular flag request, return here... */
4062 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
4063 pr_debug("no flags found for %s\n", con_id);
4068 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
4069 status = gpiod_direction_output(desc,
4070 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
4072 status = gpiod_direction_input(desc);
4078 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
4079 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4080 * @con_id: function within the GPIO consumer
4081 * @idx: index of the GPIO to obtain in the consumer
4082 * @flags: optional GPIO initialization flags
4084 * This variant of gpiod_get() allows to access GPIOs other than the first
4085 * defined one for functions that define several GPIOs.
4087 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
4088 * requested function and/or index, or another IS_ERR() code if an error
4089 * occurred while trying to acquire the GPIO.
4091 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
4094 enum gpiod_flags flags)
4096 struct gpio_desc *desc = NULL;
4098 enum gpio_lookup_flags lookupflags = 0;
4099 /* Maybe we have a device name, maybe not */
4100 const char *devname = dev ? dev_name(dev) : "?";
4102 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
4105 /* Using device tree? */
4106 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
4107 dev_dbg(dev, "using device tree for GPIO lookup\n");
4108 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
4109 } else if (ACPI_COMPANION(dev)) {
4110 dev_dbg(dev, "using ACPI for GPIO lookup\n");
4111 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
4116 * Either we are not using DT or ACPI, or their lookup did not return
4117 * a result. In that case, use platform lookup as a fallback.
4119 if (!desc || desc == ERR_PTR(-ENOENT)) {
4120 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
4121 desc = gpiod_find(dev, con_id, idx, &lookupflags);
4125 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
4130 * If a connection label was passed use that, else attempt to use
4131 * the device name as label
4133 status = gpiod_request(desc, con_id ? con_id : devname);
4135 if (status == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
4137 * This happens when there are several consumers for
4138 * the same GPIO line: we just return here without
4139 * further initialization. It is a bit if a hack.
4140 * This is necessary to support fixed regulators.
4142 * FIXME: Make this more sane and safe.
4144 dev_info(dev, "nonexclusive access to GPIO for %s\n",
4145 con_id ? con_id : devname);
4148 return ERR_PTR(status);
4152 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
4154 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
4156 return ERR_PTR(status);
4161 EXPORT_SYMBOL_GPL(gpiod_get_index);
4164 * gpiod_get_from_of_node() - obtain a GPIO from an OF node
4165 * @node: handle of the OF node
4166 * @propname: name of the DT property representing the GPIO
4167 * @index: index of the GPIO to obtain for the consumer
4168 * @dflags: GPIO initialization flags
4169 * @label: label to attach to the requested GPIO
4172 * On successful request the GPIO pin is configured in accordance with
4173 * provided @dflags. If the node does not have the requested GPIO
4174 * property, NULL is returned.
4176 * In case of error an ERR_PTR() is returned.
4178 struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
4179 const char *propname, int index,
4180 enum gpiod_flags dflags,
4183 struct gpio_desc *desc;
4184 unsigned long lflags = 0;
4185 enum of_gpio_flags flags;
4186 bool active_low = false;
4187 bool single_ended = false;
4188 bool open_drain = false;
4189 bool transitory = false;
4192 desc = of_get_named_gpiod_flags(node, propname,
4195 if (!desc || IS_ERR(desc)) {
4196 /* If it is not there, just return NULL */
4197 if (PTR_ERR(desc) == -ENOENT)
4202 active_low = flags & OF_GPIO_ACTIVE_LOW;
4203 single_ended = flags & OF_GPIO_SINGLE_ENDED;
4204 open_drain = flags & OF_GPIO_OPEN_DRAIN;
4205 transitory = flags & OF_GPIO_TRANSITORY;
4207 ret = gpiod_request(desc, label);
4209 return ERR_PTR(ret);
4212 lflags |= GPIO_ACTIVE_LOW;
4216 lflags |= GPIO_OPEN_DRAIN;
4218 lflags |= GPIO_OPEN_SOURCE;
4222 lflags |= GPIO_TRANSITORY;
4224 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4227 return ERR_PTR(ret);
4232 EXPORT_SYMBOL(gpiod_get_from_of_node);
4235 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
4236 * @fwnode: handle of the firmware node
4237 * @propname: name of the firmware property representing the GPIO
4238 * @index: index of the GPIO to obtain for the consumer
4239 * @dflags: GPIO initialization flags
4240 * @label: label to attach to the requested GPIO
4242 * This function can be used for drivers that get their configuration
4243 * from opaque firmware.
4245 * The function properly finds the corresponding GPIO using whatever is the
4246 * underlying firmware interface and then makes sure that the GPIO
4247 * descriptor is requested before it is returned to the caller.
4250 * On successful request the GPIO pin is configured in accordance with
4253 * In case of error an ERR_PTR() is returned.
4255 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
4256 const char *propname, int index,
4257 enum gpiod_flags dflags,
4260 struct gpio_desc *desc = ERR_PTR(-ENODEV);
4261 unsigned long lflags = 0;
4265 return ERR_PTR(-EINVAL);
4267 if (is_of_node(fwnode)) {
4268 desc = gpiod_get_from_of_node(to_of_node(fwnode),
4273 } else if (is_acpi_node(fwnode)) {
4274 struct acpi_gpio_info info;
4276 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4280 acpi_gpio_update_gpiod_flags(&dflags, &info);
4282 if (info.polarity == GPIO_ACTIVE_LOW)
4283 lflags |= GPIO_ACTIVE_LOW;
4286 /* Currently only ACPI takes this path */
4287 ret = gpiod_request(desc, label);
4289 return ERR_PTR(ret);
4291 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4294 return ERR_PTR(ret);
4299 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4302 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4304 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4305 * @con_id: function within the GPIO consumer
4306 * @index: index of the GPIO to obtain in the consumer
4307 * @flags: optional GPIO initialization flags
4309 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4310 * specified index was assigned to the requested function it will return NULL.
4311 * This is convenient for drivers that need to handle optional GPIOs.
4313 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4316 enum gpiod_flags flags)
4318 struct gpio_desc *desc;
4320 desc = gpiod_get_index(dev, con_id, index, flags);
4322 if (PTR_ERR(desc) == -ENOENT)
4328 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4331 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4332 * @desc: gpio whose value will be assigned
4333 * @name: gpio line name
4334 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
4336 * @dflags: gpiod_flags - optional GPIO initialization flags
4338 int gpiod_hog(struct gpio_desc *desc, const char *name,
4339 unsigned long lflags, enum gpiod_flags dflags)
4341 struct gpio_chip *chip;
4342 struct gpio_desc *local_desc;
4346 chip = gpiod_to_chip(desc);
4347 hwnum = gpio_chip_hwgpio(desc);
4349 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
4350 if (IS_ERR(local_desc)) {
4351 status = PTR_ERR(local_desc);
4352 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4353 name, chip->label, hwnum, status);
4357 status = gpiod_configure_flags(desc, name, lflags, dflags);
4359 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
4360 name, chip->label, hwnum, status);
4361 gpiochip_free_own_desc(desc);
4365 /* Mark GPIO as hogged so it can be identified and removed later */
4366 set_bit(FLAG_IS_HOGGED, &desc->flags);
4368 pr_info("GPIO line %d (%s) hogged as %s%s\n",
4369 desc_to_gpio(desc), name,
4370 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4371 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
4372 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
4378 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4379 * @chip: gpio chip to act on
4381 * This is only used by of_gpiochip_remove to free hogged gpios
4383 static void gpiochip_free_hogs(struct gpio_chip *chip)
4387 for (id = 0; id < chip->ngpio; id++) {
4388 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
4389 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
4394 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4395 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4396 * @con_id: function within the GPIO consumer
4397 * @flags: optional GPIO initialization flags
4399 * This function acquires all the GPIOs defined under a given function.
4401 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4402 * no GPIO has been assigned to the requested function, or another IS_ERR()
4403 * code if an error occurred while trying to acquire the GPIOs.
4405 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4407 enum gpiod_flags flags)
4409 struct gpio_desc *desc;
4410 struct gpio_descs *descs;
4411 struct gpio_array *array_info = NULL;
4412 struct gpio_chip *chip;
4413 int count, bitmap_size;
4415 count = gpiod_count(dev, con_id);
4417 return ERR_PTR(count);
4419 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4421 return ERR_PTR(-ENOMEM);
4423 for (descs->ndescs = 0; descs->ndescs < count; ) {
4424 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4426 gpiod_put_array(descs);
4427 return ERR_CAST(desc);
4430 descs->desc[descs->ndescs] = desc;
4432 chip = gpiod_to_chip(desc);
4434 * If pin hardware number of array member 0 is also 0, select
4435 * its chip as a candidate for fast bitmap processing path.
4437 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4438 struct gpio_descs *array;
4440 bitmap_size = BITS_TO_LONGS(chip->ngpio > count ?
4441 chip->ngpio : count);
4443 array = kzalloc(struct_size(descs, desc, count) +
4444 struct_size(array_info, invert_mask,
4445 3 * bitmap_size), GFP_KERNEL);
4447 gpiod_put_array(descs);
4448 return ERR_PTR(-ENOMEM);
4451 memcpy(array, descs,
4452 struct_size(descs, desc, descs->ndescs + 1));
4456 array_info = (void *)(descs->desc + count);
4457 array_info->get_mask = array_info->invert_mask +
4459 array_info->set_mask = array_info->get_mask +
4462 array_info->desc = descs->desc;
4463 array_info->size = count;
4464 array_info->chip = chip;
4465 bitmap_set(array_info->get_mask, descs->ndescs,
4466 count - descs->ndescs);
4467 bitmap_set(array_info->set_mask, descs->ndescs,
4468 count - descs->ndescs);
4469 descs->info = array_info;
4471 /* Unmark array members which don't belong to the 'fast' chip */
4472 if (array_info && array_info->chip != chip) {
4473 __clear_bit(descs->ndescs, array_info->get_mask);
4474 __clear_bit(descs->ndescs, array_info->set_mask);
4477 * Detect array members which belong to the 'fast' chip
4478 * but their pins are not in hardware order.
4480 else if (array_info &&
4481 gpio_chip_hwgpio(desc) != descs->ndescs) {
4483 * Don't use fast path if all array members processed so
4484 * far belong to the same chip as this one but its pin
4485 * hardware number is different from its array index.
4487 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4490 __clear_bit(descs->ndescs,
4491 array_info->get_mask);
4492 __clear_bit(descs->ndescs,
4493 array_info->set_mask);
4495 } else if (array_info) {
4496 /* Exclude open drain or open source from fast output */
4497 if (gpiochip_line_is_open_drain(chip, descs->ndescs) ||
4498 gpiochip_line_is_open_source(chip, descs->ndescs))
4499 __clear_bit(descs->ndescs,
4500 array_info->set_mask);
4501 /* Identify 'fast' pins which require invertion */
4502 if (gpiod_is_active_low(desc))
4503 __set_bit(descs->ndescs,
4504 array_info->invert_mask);
4511 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4512 array_info->chip->label, array_info->size,
4513 *array_info->get_mask, *array_info->set_mask,
4514 *array_info->invert_mask);
4517 EXPORT_SYMBOL_GPL(gpiod_get_array);
4520 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4522 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4523 * @con_id: function within the GPIO consumer
4524 * @flags: optional GPIO initialization flags
4526 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4527 * assigned to the requested function it will return NULL.
4529 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4531 enum gpiod_flags flags)
4533 struct gpio_descs *descs;
4535 descs = gpiod_get_array(dev, con_id, flags);
4536 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
4541 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4544 * gpiod_put - dispose of a GPIO descriptor
4545 * @desc: GPIO descriptor to dispose of
4547 * No descriptor can be used after gpiod_put() has been called on it.
4549 void gpiod_put(struct gpio_desc *desc)
4553 EXPORT_SYMBOL_GPL(gpiod_put);
4556 * gpiod_put_array - dispose of multiple GPIO descriptors
4557 * @descs: struct gpio_descs containing an array of descriptors
4559 void gpiod_put_array(struct gpio_descs *descs)
4563 for (i = 0; i < descs->ndescs; i++)
4564 gpiod_put(descs->desc[i]);
4568 EXPORT_SYMBOL_GPL(gpiod_put_array);
4570 static int __init gpiolib_dev_init(void)
4574 /* Register GPIO sysfs bus */
4575 ret = bus_register(&gpio_bus_type);
4577 pr_err("gpiolib: could not register GPIO bus type\n");
4581 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
4583 pr_err("gpiolib: failed to allocate char dev region\n");
4584 bus_unregister(&gpio_bus_type);
4586 gpiolib_initialized = true;
4587 gpiochip_setup_devs();
4591 core_initcall(gpiolib_dev_init);
4593 #ifdef CONFIG_DEBUG_FS
4595 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4598 struct gpio_chip *chip = gdev->chip;
4599 unsigned gpio = gdev->base;
4600 struct gpio_desc *gdesc = &gdev->descs[0];
4605 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4606 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4608 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4614 gpiod_get_direction(gdesc);
4615 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4616 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4617 active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
4618 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
4619 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4620 is_out ? "out" : "in ",
4621 chip->get ? (chip->get(chip, i) ? "hi" : "lo") : "? ",
4622 is_irq ? "IRQ " : "",
4623 active_low ? "ACTIVE LOW" : "");
4624 seq_printf(s, "\n");
4628 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4630 unsigned long flags;
4631 struct gpio_device *gdev = NULL;
4632 loff_t index = *pos;
4636 spin_lock_irqsave(&gpio_lock, flags);
4637 list_for_each_entry(gdev, &gpio_devices, list)
4639 spin_unlock_irqrestore(&gpio_lock, flags);
4642 spin_unlock_irqrestore(&gpio_lock, flags);
4647 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4649 unsigned long flags;
4650 struct gpio_device *gdev = v;
4653 spin_lock_irqsave(&gpio_lock, flags);
4654 if (list_is_last(&gdev->list, &gpio_devices))
4657 ret = list_entry(gdev->list.next, struct gpio_device, list);
4658 spin_unlock_irqrestore(&gpio_lock, flags);
4666 static void gpiolib_seq_stop(struct seq_file *s, void *v)
4670 static int gpiolib_seq_show(struct seq_file *s, void *v)
4672 struct gpio_device *gdev = v;
4673 struct gpio_chip *chip = gdev->chip;
4674 struct device *parent;
4677 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4678 dev_name(&gdev->dev));
4682 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4683 dev_name(&gdev->dev),
4684 gdev->base, gdev->base + gdev->ngpio - 1);
4685 parent = chip->parent;
4687 seq_printf(s, ", parent: %s/%s",
4688 parent->bus ? parent->bus->name : "no-bus",
4691 seq_printf(s, ", %s", chip->label);
4692 if (chip->can_sleep)
4693 seq_printf(s, ", can sleep");
4694 seq_printf(s, ":\n");
4697 chip->dbg_show(s, chip);
4699 gpiolib_dbg_show(s, gdev);
4704 static const struct seq_operations gpiolib_seq_ops = {
4705 .start = gpiolib_seq_start,
4706 .next = gpiolib_seq_next,
4707 .stop = gpiolib_seq_stop,
4708 .show = gpiolib_seq_show,
4711 static int gpiolib_open(struct inode *inode, struct file *file)
4713 return seq_open(file, &gpiolib_seq_ops);
4716 static const struct file_operations gpiolib_operations = {
4717 .owner = THIS_MODULE,
4718 .open = gpiolib_open,
4720 .llseek = seq_lseek,
4721 .release = seq_release,
4724 static int __init gpiolib_debugfs_init(void)
4726 /* /sys/kernel/debug/gpio */
4727 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
4728 NULL, NULL, &gpiolib_operations);
4731 subsys_initcall(gpiolib_debugfs_init);
4733 #endif /* DEBUG_FS */