1 #include <linux/bitmap.h>
2 #include <linux/kernel.h>
3 #include <linux/module.h>
4 #include <linux/interrupt.h>
6 #include <linux/spinlock.h>
7 #include <linux/list.h>
8 #include <linux/device.h>
10 #include <linux/debugfs.h>
11 #include <linux/seq_file.h>
12 #include <linux/gpio.h>
13 #include <linux/of_gpio.h>
14 #include <linux/idr.h>
15 #include <linux/slab.h>
16 #include <linux/acpi.h>
17 #include <linux/gpio/driver.h>
18 #include <linux/gpio/machine.h>
19 #include <linux/pinctrl/consumer.h>
20 #include <linux/cdev.h>
22 #include <linux/uaccess.h>
23 #include <linux/compat.h>
24 #include <linux/anon_inodes.h>
25 #include <linux/file.h>
26 #include <linux/kfifo.h>
27 #include <linux/poll.h>
28 #include <linux/timekeeping.h>
29 #include <uapi/linux/gpio.h>
33 #define CREATE_TRACE_POINTS
34 #include <trace/events/gpio.h>
36 /* Implementation infrastructure for GPIO interfaces.
38 * The GPIO programming interface allows for inlining speed-critical
39 * get/set operations for common cases, so that access to SOC-integrated
40 * GPIOs can sometimes cost only an instruction or two per bit.
44 /* When debugging, extend minimal trust to callers and platform code.
45 * Also emit diagnostic messages that may help initial bringup, when
46 * board setup or driver bugs are most common.
48 * Otherwise, minimize overhead in what may be bitbanging codepaths.
51 #define extra_checks 1
53 #define extra_checks 0
56 /* Device and char device-related information */
57 static DEFINE_IDA(gpio_ida);
58 static dev_t gpio_devt;
59 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
60 static struct bus_type gpio_bus_type = {
65 * Number of GPIOs to use for the fast path in set array
67 #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
69 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
70 * While any GPIO is requested, its gpio_chip is not removable;
71 * each GPIO's "requested" flag serves as a lock and refcount.
73 DEFINE_SPINLOCK(gpio_lock);
75 static DEFINE_MUTEX(gpio_lookup_lock);
76 static LIST_HEAD(gpio_lookup_list);
77 LIST_HEAD(gpio_devices);
79 static DEFINE_MUTEX(gpio_machine_hogs_mutex);
80 static LIST_HEAD(gpio_machine_hogs);
82 static void gpiochip_free_hogs(struct gpio_chip *chip);
83 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
84 struct lock_class_key *lock_key,
85 struct lock_class_key *request_key);
86 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
87 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
88 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
90 static bool gpiolib_initialized;
92 static inline void desc_set_label(struct gpio_desc *d, const char *label)
98 * gpio_to_desc - Convert a GPIO number to its descriptor
99 * @gpio: global GPIO number
102 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
103 * with the given number exists in the system.
105 struct gpio_desc *gpio_to_desc(unsigned gpio)
107 struct gpio_device *gdev;
110 spin_lock_irqsave(&gpio_lock, flags);
112 list_for_each_entry(gdev, &gpio_devices, list) {
113 if (gdev->base <= gpio &&
114 gdev->base + gdev->ngpio > gpio) {
115 spin_unlock_irqrestore(&gpio_lock, flags);
116 return &gdev->descs[gpio - gdev->base];
120 spin_unlock_irqrestore(&gpio_lock, flags);
122 if (!gpio_is_valid(gpio))
123 WARN(1, "invalid GPIO %d\n", gpio);
127 EXPORT_SYMBOL_GPL(gpio_to_desc);
130 * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
131 * hardware number for this chip
133 * @hwnum: hardware number of the GPIO for this chip
136 * A pointer to the GPIO descriptor or %ERR_PTR(-EINVAL) if no GPIO exists
137 * in the given chip for the specified hardware number.
139 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
142 struct gpio_device *gdev = chip->gpiodev;
144 if (hwnum >= gdev->ngpio)
145 return ERR_PTR(-EINVAL);
147 return &gdev->descs[hwnum];
151 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
152 * @desc: GPIO descriptor
154 * This should disappear in the future but is needed since we still
155 * use GPIO numbers for error messages and sysfs nodes.
158 * The global GPIO number for the GPIO specified by its descriptor.
160 int desc_to_gpio(const struct gpio_desc *desc)
162 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
164 EXPORT_SYMBOL_GPL(desc_to_gpio);
168 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
169 * @desc: descriptor to return the chip of
171 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
173 if (!desc || !desc->gdev)
175 return desc->gdev->chip;
177 EXPORT_SYMBOL_GPL(gpiod_to_chip);
179 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
180 static int gpiochip_find_base(int ngpio)
182 struct gpio_device *gdev;
183 int base = ARCH_NR_GPIOS - ngpio;
185 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
186 /* found a free space? */
187 if (gdev->base + gdev->ngpio <= base)
190 /* nope, check the space right before the chip */
191 base = gdev->base - ngpio;
194 if (gpio_is_valid(base)) {
195 pr_debug("%s: found new base at %d\n", __func__, base);
198 pr_err("%s: cannot find free range\n", __func__);
204 * gpiod_get_direction - return the current direction of a GPIO
205 * @desc: GPIO to get the direction of
207 * Returns 0 for output, 1 for input, or an error code in case of error.
209 * This function may sleep if gpiod_cansleep() is true.
211 int gpiod_get_direction(struct gpio_desc *desc)
213 struct gpio_chip *chip;
215 int status = -EINVAL;
217 chip = gpiod_to_chip(desc);
218 offset = gpio_chip_hwgpio(desc);
221 * Open drain emulation using input mode may incorrectly report
222 * input here, fix that up.
224 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) &&
225 test_bit(FLAG_IS_OUT, &desc->flags))
228 if (!chip->get_direction)
231 status = chip->get_direction(chip, offset);
233 /* GPIOF_DIR_IN, or other positive */
235 clear_bit(FLAG_IS_OUT, &desc->flags);
239 set_bit(FLAG_IS_OUT, &desc->flags);
243 EXPORT_SYMBOL_GPL(gpiod_get_direction);
246 * Add a new chip to the global chips list, keeping the list of chips sorted
247 * by range(means [base, base + ngpio - 1]) order.
249 * Return -EBUSY if the new chip overlaps with some other chip's integer
252 static int gpiodev_add_to_list(struct gpio_device *gdev)
254 struct gpio_device *prev, *next;
256 if (list_empty(&gpio_devices)) {
257 /* initial entry in list */
258 list_add_tail(&gdev->list, &gpio_devices);
262 next = list_entry(gpio_devices.next, struct gpio_device, list);
263 if (gdev->base + gdev->ngpio <= next->base) {
264 /* add before first entry */
265 list_add(&gdev->list, &gpio_devices);
269 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
270 if (prev->base + prev->ngpio <= gdev->base) {
271 /* add behind last entry */
272 list_add_tail(&gdev->list, &gpio_devices);
276 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
277 /* at the end of the list */
278 if (&next->list == &gpio_devices)
281 /* add between prev and next */
282 if (prev->base + prev->ngpio <= gdev->base
283 && gdev->base + gdev->ngpio <= next->base) {
284 list_add(&gdev->list, &prev->list);
289 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
294 * Convert a GPIO name to its descriptor
296 static struct gpio_desc *gpio_name_to_desc(const char * const name)
298 struct gpio_device *gdev;
301 spin_lock_irqsave(&gpio_lock, flags);
303 list_for_each_entry(gdev, &gpio_devices, list) {
306 for (i = 0; i != gdev->ngpio; ++i) {
307 struct gpio_desc *desc = &gdev->descs[i];
309 if (!desc->name || !name)
312 if (!strcmp(desc->name, name)) {
313 spin_unlock_irqrestore(&gpio_lock, flags);
319 spin_unlock_irqrestore(&gpio_lock, flags);
325 * Takes the names from gc->names and checks if they are all unique. If they
326 * are, they are assigned to their gpio descriptors.
328 * Warning if one of the names is already used for a different GPIO.
330 static int gpiochip_set_desc_names(struct gpio_chip *gc)
332 struct gpio_device *gdev = gc->gpiodev;
338 /* First check all names if they are unique */
339 for (i = 0; i != gc->ngpio; ++i) {
340 struct gpio_desc *gpio;
342 gpio = gpio_name_to_desc(gc->names[i]);
345 "Detected name collision for GPIO name '%s'\n",
349 /* Then add all names to the GPIO descriptors */
350 for (i = 0; i != gc->ngpio; ++i)
351 gdev->descs[i].name = gc->names[i];
356 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *chip)
360 p = kmalloc_array(BITS_TO_LONGS(chip->ngpio), sizeof(*p), GFP_KERNEL);
364 /* Assume by default all GPIOs are valid */
365 bitmap_fill(p, chip->ngpio);
370 static int gpiochip_init_valid_mask(struct gpio_chip *gpiochip)
372 #ifdef CONFIG_OF_GPIO
374 struct device_node *np = gpiochip->of_node;
376 size = of_property_count_u32_elems(np, "gpio-reserved-ranges");
377 if (size > 0 && size % 2 == 0)
378 gpiochip->need_valid_mask = true;
381 if (!gpiochip->need_valid_mask)
384 gpiochip->valid_mask = gpiochip_allocate_mask(gpiochip);
385 if (!gpiochip->valid_mask)
391 static void gpiochip_free_valid_mask(struct gpio_chip *gpiochip)
393 kfree(gpiochip->valid_mask);
394 gpiochip->valid_mask = NULL;
397 bool gpiochip_line_is_valid(const struct gpio_chip *gpiochip,
400 /* No mask means all valid */
401 if (likely(!gpiochip->valid_mask))
403 return test_bit(offset, gpiochip->valid_mask);
405 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
408 * GPIO line handle management
412 * struct linehandle_state - contains the state of a userspace handle
413 * @gdev: the GPIO device the handle pertains to
414 * @label: consumer label used to tag descriptors
415 * @descs: the GPIO descriptors held by this handle
416 * @numdescs: the number of descriptors held in the descs array
418 struct linehandle_state {
419 struct gpio_device *gdev;
421 struct gpio_desc *descs[GPIOHANDLES_MAX];
425 #define GPIOHANDLE_REQUEST_VALID_FLAGS \
426 (GPIOHANDLE_REQUEST_INPUT | \
427 GPIOHANDLE_REQUEST_OUTPUT | \
428 GPIOHANDLE_REQUEST_ACTIVE_LOW | \
429 GPIOHANDLE_REQUEST_OPEN_DRAIN | \
430 GPIOHANDLE_REQUEST_OPEN_SOURCE)
432 static long linehandle_ioctl(struct file *filep, unsigned int cmd,
435 struct linehandle_state *lh = filep->private_data;
436 void __user *ip = (void __user *)arg;
437 struct gpiohandle_data ghd;
438 int vals[GPIOHANDLES_MAX];
441 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
442 /* NOTE: It's ok to read values of output lines. */
443 int ret = gpiod_get_array_value_complex(false,
451 memset(&ghd, 0, sizeof(ghd));
452 for (i = 0; i < lh->numdescs; i++)
453 ghd.values[i] = vals[i];
455 if (copy_to_user(ip, &ghd, sizeof(ghd)))
459 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
461 * All line descriptors were created at once with the same
462 * flags so just check if the first one is really output.
464 if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags))
467 if (copy_from_user(&ghd, ip, sizeof(ghd)))
470 /* Clamp all values to [0,1] */
471 for (i = 0; i < lh->numdescs; i++)
472 vals[i] = !!ghd.values[i];
474 /* Reuse the array setting function */
475 return gpiod_set_array_value_complex(false,
485 static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
488 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
492 static int linehandle_release(struct inode *inode, struct file *filep)
494 struct linehandle_state *lh = filep->private_data;
495 struct gpio_device *gdev = lh->gdev;
498 for (i = 0; i < lh->numdescs; i++)
499 gpiod_free(lh->descs[i]);
502 put_device(&gdev->dev);
506 static const struct file_operations linehandle_fileops = {
507 .release = linehandle_release,
508 .owner = THIS_MODULE,
509 .llseek = noop_llseek,
510 .unlocked_ioctl = linehandle_ioctl,
512 .compat_ioctl = linehandle_ioctl_compat,
516 static int linehandle_create(struct gpio_device *gdev, void __user *ip)
518 struct gpiohandle_request handlereq;
519 struct linehandle_state *lh;
521 int fd, i, count = 0, ret;
524 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
526 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
529 lflags = handlereq.flags;
531 /* Return an error if an unknown flag is set */
532 if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
536 * Do not allow both INPUT & OUTPUT flags to be set as they are
539 if ((lflags & GPIOHANDLE_REQUEST_INPUT) &&
540 (lflags & GPIOHANDLE_REQUEST_OUTPUT))
544 * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
545 * the hardware actually supports enabling both at the same time the
546 * electrical result would be disastrous.
548 if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
549 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
552 /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
553 if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) &&
554 ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
555 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
558 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
562 get_device(&gdev->dev);
564 /* Make sure this is terminated */
565 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
566 if (strlen(handlereq.consumer_label)) {
567 lh->label = kstrdup(handlereq.consumer_label,
575 /* Request each GPIO */
576 for (i = 0; i < handlereq.lines; i++) {
577 u32 offset = handlereq.lineoffsets[i];
578 struct gpio_desc *desc;
580 if (offset >= gdev->ngpio) {
585 desc = &gdev->descs[offset];
586 ret = gpiod_request(desc, lh->label);
592 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
593 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
594 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
595 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
596 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
597 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
599 ret = gpiod_set_transitory(desc, false);
604 * Lines have to be requested explicitly for input
605 * or output, else the line will be treated "as is".
607 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
608 int val = !!handlereq.default_values[i];
610 ret = gpiod_direction_output(desc, val);
613 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
614 ret = gpiod_direction_input(desc);
618 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
621 /* Let i point at the last handle */
623 lh->numdescs = handlereq.lines;
625 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
631 file = anon_inode_getfile("gpio-linehandle",
634 O_RDONLY | O_CLOEXEC);
637 goto out_put_unused_fd;
641 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
643 * fput() will trigger the release() callback, so do not go onto
644 * the regular error cleanup path here.
651 fd_install(fd, file);
653 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
661 for (i = 0; i < count; i++)
662 gpiod_free(lh->descs[i]);
666 put_device(&gdev->dev);
671 * GPIO line event management
675 * struct lineevent_state - contains the state of a userspace event
676 * @gdev: the GPIO device the event pertains to
677 * @label: consumer label used to tag descriptors
678 * @desc: the GPIO descriptor held by this event
679 * @eflags: the event flags this line was requested with
680 * @irq: the interrupt that trigger in response to events on this GPIO
681 * @wait: wait queue that handles blocking reads of events
682 * @events: KFIFO for the GPIO events
683 * @read_lock: mutex lock to protect reads from colliding with adding
684 * new events to the FIFO
685 * @timestamp: cache for the timestamp storing it between hardirq
686 * and IRQ thread, used to bring the timestamp close to the actual
689 struct lineevent_state {
690 struct gpio_device *gdev;
692 struct gpio_desc *desc;
695 wait_queue_head_t wait;
696 DECLARE_KFIFO(events, struct gpioevent_data, 16);
697 struct mutex read_lock;
701 #define GPIOEVENT_REQUEST_VALID_FLAGS \
702 (GPIOEVENT_REQUEST_RISING_EDGE | \
703 GPIOEVENT_REQUEST_FALLING_EDGE)
705 static __poll_t lineevent_poll(struct file *filep,
706 struct poll_table_struct *wait)
708 struct lineevent_state *le = filep->private_data;
711 poll_wait(filep, &le->wait, wait);
713 if (!kfifo_is_empty(&le->events))
714 events = EPOLLIN | EPOLLRDNORM;
720 static ssize_t lineevent_read(struct file *filep,
725 struct lineevent_state *le = filep->private_data;
729 if (count < sizeof(struct gpioevent_data))
733 if (kfifo_is_empty(&le->events)) {
734 if (filep->f_flags & O_NONBLOCK)
737 ret = wait_event_interruptible(le->wait,
738 !kfifo_is_empty(&le->events));
743 if (mutex_lock_interruptible(&le->read_lock))
745 ret = kfifo_to_user(&le->events, buf, count, &copied);
746 mutex_unlock(&le->read_lock);
752 * If we couldn't read anything from the fifo (a different
753 * thread might have been faster) we either return -EAGAIN if
754 * the file descriptor is non-blocking, otherwise we go back to
755 * sleep and wait for more data to arrive.
757 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
760 } while (copied == 0);
765 static int lineevent_release(struct inode *inode, struct file *filep)
767 struct lineevent_state *le = filep->private_data;
768 struct gpio_device *gdev = le->gdev;
770 free_irq(le->irq, le);
771 gpiod_free(le->desc);
774 put_device(&gdev->dev);
778 static long lineevent_ioctl(struct file *filep, unsigned int cmd,
781 struct lineevent_state *le = filep->private_data;
782 void __user *ip = (void __user *)arg;
783 struct gpiohandle_data ghd;
786 * We can get the value for an event line but not set it,
787 * because it is input by definition.
789 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
792 memset(&ghd, 0, sizeof(ghd));
794 val = gpiod_get_value_cansleep(le->desc);
799 if (copy_to_user(ip, &ghd, sizeof(ghd)))
808 static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
811 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
815 static const struct file_operations lineevent_fileops = {
816 .release = lineevent_release,
817 .read = lineevent_read,
818 .poll = lineevent_poll,
819 .owner = THIS_MODULE,
820 .llseek = noop_llseek,
821 .unlocked_ioctl = lineevent_ioctl,
823 .compat_ioctl = lineevent_ioctl_compat,
827 static irqreturn_t lineevent_irq_thread(int irq, void *p)
829 struct lineevent_state *le = p;
830 struct gpioevent_data ge;
833 /* Do not leak kernel stack to userspace */
834 memset(&ge, 0, sizeof(ge));
837 * We may be running from a nested threaded interrupt in which case
838 * we didn't get the timestamp from lineevent_irq_handler().
841 ge.timestamp = ktime_get_real_ns();
843 ge.timestamp = le->timestamp;
845 level = gpiod_get_value_cansleep(le->desc);
847 if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
848 && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
850 /* Emit low-to-high event */
851 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
853 /* Emit high-to-low event */
854 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
855 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE && level) {
856 /* Emit low-to-high event */
857 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
858 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE && !level) {
859 /* Emit high-to-low event */
860 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
865 ret = kfifo_put(&le->events, ge);
867 wake_up_poll(&le->wait, EPOLLIN);
872 static irqreturn_t lineevent_irq_handler(int irq, void *p)
874 struct lineevent_state *le = p;
877 * Just store the timestamp in hardirq context so we get it as
878 * close in time as possible to the actual event.
880 le->timestamp = ktime_get_real_ns();
882 return IRQ_WAKE_THREAD;
885 static int lineevent_create(struct gpio_device *gdev, void __user *ip)
887 struct gpioevent_request eventreq;
888 struct lineevent_state *le;
889 struct gpio_desc *desc;
898 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
901 le = kzalloc(sizeof(*le), GFP_KERNEL);
905 get_device(&gdev->dev);
907 /* Make sure this is terminated */
908 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
909 if (strlen(eventreq.consumer_label)) {
910 le->label = kstrdup(eventreq.consumer_label,
918 offset = eventreq.lineoffset;
919 lflags = eventreq.handleflags;
920 eflags = eventreq.eventflags;
922 if (offset >= gdev->ngpio) {
927 /* Return an error if a unknown flag is set */
928 if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
929 (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
934 /* This is just wrong: we don't look for events on output lines */
935 if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) ||
936 (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
937 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) {
942 desc = &gdev->descs[offset];
943 ret = gpiod_request(desc, le->label);
949 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
950 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
952 ret = gpiod_direction_input(desc);
956 le->irq = gpiod_to_irq(desc);
962 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
963 irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
964 IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
965 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
966 irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
967 IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
968 irqflags |= IRQF_ONESHOT;
969 irqflags |= IRQF_SHARED;
971 INIT_KFIFO(le->events);
972 init_waitqueue_head(&le->wait);
973 mutex_init(&le->read_lock);
975 /* Request a thread to read the events */
976 ret = request_threaded_irq(le->irq,
977 lineevent_irq_handler,
978 lineevent_irq_thread,
985 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
991 file = anon_inode_getfile("gpio-event",
994 O_RDONLY | O_CLOEXEC);
997 goto out_put_unused_fd;
1001 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
1003 * fput() will trigger the release() callback, so do not go onto
1004 * the regular error cleanup path here.
1011 fd_install(fd, file);
1018 free_irq(le->irq, le);
1020 gpiod_free(le->desc);
1025 put_device(&gdev->dev);
1030 * gpio_ioctl() - ioctl handler for the GPIO chardev
1032 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1034 struct gpio_device *gdev = filp->private_data;
1035 struct gpio_chip *chip = gdev->chip;
1036 void __user *ip = (void __user *)arg;
1038 /* We fail any subsequent ioctl():s when the chip is gone */
1042 /* Fill in the struct and pass to userspace */
1043 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
1044 struct gpiochip_info chipinfo;
1046 memset(&chipinfo, 0, sizeof(chipinfo));
1048 strncpy(chipinfo.name, dev_name(&gdev->dev),
1049 sizeof(chipinfo.name));
1050 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
1051 strncpy(chipinfo.label, gdev->label,
1052 sizeof(chipinfo.label));
1053 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
1054 chipinfo.lines = gdev->ngpio;
1055 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
1058 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
1059 struct gpioline_info lineinfo;
1060 struct gpio_desc *desc;
1062 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
1064 if (lineinfo.line_offset >= gdev->ngpio)
1067 desc = &gdev->descs[lineinfo.line_offset];
1069 strncpy(lineinfo.name, desc->name,
1070 sizeof(lineinfo.name));
1071 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
1073 lineinfo.name[0] = '\0';
1076 strncpy(lineinfo.consumer, desc->label,
1077 sizeof(lineinfo.consumer));
1078 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
1080 lineinfo.consumer[0] = '\0';
1084 * Userspace only need to know that the kernel is using
1085 * this GPIO so it can't use it.
1088 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
1089 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
1090 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
1091 test_bit(FLAG_EXPORT, &desc->flags) ||
1092 test_bit(FLAG_SYSFS, &desc->flags))
1093 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
1094 if (test_bit(FLAG_IS_OUT, &desc->flags))
1095 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
1096 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1097 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
1098 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1099 lineinfo.flags |= (GPIOLINE_FLAG_OPEN_DRAIN |
1100 GPIOLINE_FLAG_IS_OUT);
1101 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1102 lineinfo.flags |= (GPIOLINE_FLAG_OPEN_SOURCE |
1103 GPIOLINE_FLAG_IS_OUT);
1105 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
1108 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
1109 return linehandle_create(gdev, ip);
1110 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
1111 return lineevent_create(gdev, ip);
1116 #ifdef CONFIG_COMPAT
1117 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
1120 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
1125 * gpio_chrdev_open() - open the chardev for ioctl operations
1126 * @inode: inode for this chardev
1127 * @filp: file struct for storing private data
1128 * Returns 0 on success
1130 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
1132 struct gpio_device *gdev = container_of(inode->i_cdev,
1133 struct gpio_device, chrdev);
1135 /* Fail on open if the backing gpiochip is gone */
1138 get_device(&gdev->dev);
1139 filp->private_data = gdev;
1141 return nonseekable_open(inode, filp);
1145 * gpio_chrdev_release() - close chardev after ioctl operations
1146 * @inode: inode for this chardev
1147 * @filp: file struct for storing private data
1148 * Returns 0 on success
1150 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1152 struct gpio_device *gdev = container_of(inode->i_cdev,
1153 struct gpio_device, chrdev);
1155 put_device(&gdev->dev);
1160 static const struct file_operations gpio_fileops = {
1161 .release = gpio_chrdev_release,
1162 .open = gpio_chrdev_open,
1163 .owner = THIS_MODULE,
1164 .llseek = no_llseek,
1165 .unlocked_ioctl = gpio_ioctl,
1166 #ifdef CONFIG_COMPAT
1167 .compat_ioctl = gpio_ioctl_compat,
1171 static void gpiodevice_release(struct device *dev)
1173 struct gpio_device *gdev = dev_get_drvdata(dev);
1175 list_del(&gdev->list);
1176 ida_simple_remove(&gpio_ida, gdev->id);
1177 kfree_const(gdev->label);
1182 static int gpiochip_setup_dev(struct gpio_device *gdev)
1186 cdev_init(&gdev->chrdev, &gpio_fileops);
1187 gdev->chrdev.owner = THIS_MODULE;
1188 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1190 status = cdev_device_add(&gdev->chrdev, &gdev->dev);
1194 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1195 MAJOR(gpio_devt), gdev->id);
1197 status = gpiochip_sysfs_register(gdev);
1199 goto err_remove_device;
1201 /* From this point, the .release() function cleans up gpio_device */
1202 gdev->dev.release = gpiodevice_release;
1203 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1204 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1205 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1210 cdev_device_del(&gdev->chrdev, &gdev->dev);
1214 static void gpiochip_machine_hog(struct gpio_chip *chip, struct gpiod_hog *hog)
1216 struct gpio_desc *desc;
1219 desc = gpiochip_get_desc(chip, hog->chip_hwnum);
1221 pr_err("%s: unable to get GPIO desc: %ld\n",
1222 __func__, PTR_ERR(desc));
1226 if (test_bit(FLAG_IS_HOGGED, &desc->flags))
1229 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
1231 pr_err("%s: unable to hog GPIO line (%s:%u): %d\n",
1232 __func__, chip->label, hog->chip_hwnum, rv);
1235 static void machine_gpiochip_add(struct gpio_chip *chip)
1237 struct gpiod_hog *hog;
1239 mutex_lock(&gpio_machine_hogs_mutex);
1241 list_for_each_entry(hog, &gpio_machine_hogs, list) {
1242 if (!strcmp(chip->label, hog->chip_label))
1243 gpiochip_machine_hog(chip, hog);
1246 mutex_unlock(&gpio_machine_hogs_mutex);
1249 static void gpiochip_setup_devs(void)
1251 struct gpio_device *gdev;
1254 list_for_each_entry(gdev, &gpio_devices, list) {
1255 err = gpiochip_setup_dev(gdev);
1257 pr_err("%s: Failed to initialize gpio device (%d)\n",
1258 dev_name(&gdev->dev), err);
1262 int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
1263 struct lock_class_key *lock_key,
1264 struct lock_class_key *request_key)
1266 unsigned long flags;
1269 int base = chip->base;
1270 struct gpio_device *gdev;
1273 * First: allocate and populate the internal stat container, and
1274 * set up the struct device.
1276 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1279 gdev->dev.bus = &gpio_bus_type;
1281 chip->gpiodev = gdev;
1283 gdev->dev.parent = chip->parent;
1284 gdev->dev.of_node = chip->parent->of_node;
1287 #ifdef CONFIG_OF_GPIO
1288 /* If the gpiochip has an assigned OF node this takes precedence */
1290 gdev->dev.of_node = chip->of_node;
1292 chip->of_node = gdev->dev.of_node;
1295 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1300 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1301 device_initialize(&gdev->dev);
1302 dev_set_drvdata(&gdev->dev, gdev);
1303 if (chip->parent && chip->parent->driver)
1304 gdev->owner = chip->parent->driver->owner;
1305 else if (chip->owner)
1306 /* TODO: remove chip->owner */
1307 gdev->owner = chip->owner;
1309 gdev->owner = THIS_MODULE;
1311 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1317 if (chip->ngpio == 0) {
1318 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1320 goto err_free_descs;
1323 if (chip->ngpio > FASTPATH_NGPIO)
1324 chip_warn(chip, "line cnt %u is greater than fast path cnt %u\n",
1325 chip->ngpio, FASTPATH_NGPIO);
1327 gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
1330 goto err_free_descs;
1333 gdev->ngpio = chip->ngpio;
1336 spin_lock_irqsave(&gpio_lock, flags);
1339 * TODO: this allocates a Linux GPIO number base in the global
1340 * GPIO numberspace for this chip. In the long run we want to
1341 * get *rid* of this numberspace and use only descriptors, but
1342 * it may be a pipe dream. It will not happen before we get rid
1343 * of the sysfs interface anyways.
1346 base = gpiochip_find_base(chip->ngpio);
1349 spin_unlock_irqrestore(&gpio_lock, flags);
1350 goto err_free_label;
1353 * TODO: it should not be necessary to reflect the assigned
1354 * base outside of the GPIO subsystem. Go over drivers and
1355 * see if anyone makes use of this, else drop this and assign
1362 status = gpiodev_add_to_list(gdev);
1364 spin_unlock_irqrestore(&gpio_lock, flags);
1365 goto err_free_label;
1368 spin_unlock_irqrestore(&gpio_lock, flags);
1370 for (i = 0; i < chip->ngpio; i++) {
1371 struct gpio_desc *desc = &gdev->descs[i];
1375 /* REVISIT: most hardware initializes GPIOs as inputs (often
1376 * with pullups enabled) so power usage is minimized. Linux
1377 * code should set the gpio direction first thing; but until
1378 * it does, and in case chip->get_direction is not set, we may
1379 * expose the wrong direction in sysfs.
1381 desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
1384 #ifdef CONFIG_PINCTRL
1385 INIT_LIST_HEAD(&gdev->pin_ranges);
1388 status = gpiochip_set_desc_names(chip);
1390 goto err_remove_from_list;
1392 status = gpiochip_irqchip_init_valid_mask(chip);
1394 goto err_remove_from_list;
1396 status = gpiochip_init_valid_mask(chip);
1398 goto err_remove_irqchip_mask;
1400 status = gpiochip_add_irqchip(chip, lock_key, request_key);
1402 goto err_remove_chip;
1404 status = of_gpiochip_add(chip);
1406 goto err_remove_chip;
1408 acpi_gpiochip_add(chip);
1410 machine_gpiochip_add(chip);
1413 * By first adding the chardev, and then adding the device,
1414 * we get a device node entry in sysfs under
1415 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1416 * coldplug of device nodes and other udev business.
1417 * We can do this only if gpiolib has been initialized.
1418 * Otherwise, defer until later.
1420 if (gpiolib_initialized) {
1421 status = gpiochip_setup_dev(gdev);
1423 goto err_remove_chip;
1428 acpi_gpiochip_remove(chip);
1429 gpiochip_free_hogs(chip);
1430 of_gpiochip_remove(chip);
1431 gpiochip_free_valid_mask(chip);
1432 err_remove_irqchip_mask:
1433 gpiochip_irqchip_free_valid_mask(chip);
1434 err_remove_from_list:
1435 spin_lock_irqsave(&gpio_lock, flags);
1436 list_del(&gdev->list);
1437 spin_unlock_irqrestore(&gpio_lock, flags);
1439 kfree_const(gdev->label);
1443 ida_simple_remove(&gpio_ida, gdev->id);
1445 /* failures here can mean systems won't boot... */
1446 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1447 gdev->base, gdev->base + gdev->ngpio - 1,
1448 chip->label ? : "generic", status);
1452 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1455 * gpiochip_get_data() - get per-subdriver data for the chip
1459 * The per-subdriver data for the chip.
1461 void *gpiochip_get_data(struct gpio_chip *chip)
1463 return chip->gpiodev->data;
1465 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1468 * gpiochip_remove() - unregister a gpio_chip
1469 * @chip: the chip to unregister
1471 * A gpio_chip with any GPIOs still requested may not be removed.
1473 void gpiochip_remove(struct gpio_chip *chip)
1475 struct gpio_device *gdev = chip->gpiodev;
1476 struct gpio_desc *desc;
1477 unsigned long flags;
1479 bool requested = false;
1481 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1482 gpiochip_sysfs_unregister(gdev);
1483 gpiochip_free_hogs(chip);
1484 /* Numb the device, cancelling all outstanding operations */
1486 gpiochip_irqchip_remove(chip);
1487 acpi_gpiochip_remove(chip);
1488 gpiochip_remove_pin_ranges(chip);
1489 of_gpiochip_remove(chip);
1490 gpiochip_free_valid_mask(chip);
1492 * We accept no more calls into the driver from this point, so
1493 * NULL the driver data pointer
1497 spin_lock_irqsave(&gpio_lock, flags);
1498 for (i = 0; i < gdev->ngpio; i++) {
1499 desc = &gdev->descs[i];
1500 if (test_bit(FLAG_REQUESTED, &desc->flags))
1503 spin_unlock_irqrestore(&gpio_lock, flags);
1506 dev_crit(&gdev->dev,
1507 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1510 * The gpiochip side puts its use of the device to rest here:
1511 * if there are no userspace clients, the chardev and device will
1512 * be removed, else it will be dangling until the last user is
1515 cdev_device_del(&gdev->chrdev, &gdev->dev);
1516 put_device(&gdev->dev);
1518 EXPORT_SYMBOL_GPL(gpiochip_remove);
1520 static void devm_gpio_chip_release(struct device *dev, void *res)
1522 struct gpio_chip *chip = *(struct gpio_chip **)res;
1524 gpiochip_remove(chip);
1527 static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
1530 struct gpio_chip **r = res;
1541 * devm_gpiochip_add_data() - Resource manager gpiochip_add_data()
1542 * @dev: the device pointer on which irq_chip belongs to.
1543 * @chip: the chip to register, with chip->base initialized
1544 * @data: driver-private data associated with this chip
1546 * Context: potentially before irqs will work
1548 * The gpio chip automatically be released when the device is unbound.
1551 * A negative errno if the chip can't be registered, such as because the
1552 * chip->base is invalid or already associated with a different chip.
1553 * Otherwise it returns zero as a success code.
1555 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1558 struct gpio_chip **ptr;
1561 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1566 ret = gpiochip_add_data(chip, data);
1573 devres_add(dev, ptr);
1577 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1580 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1581 * @dev: device for which which resource was allocated
1582 * @chip: the chip to remove
1584 * A gpio_chip with any GPIOs still requested may not be removed.
1586 void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
1590 ret = devres_release(dev, devm_gpio_chip_release,
1591 devm_gpio_chip_match, chip);
1594 EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
1597 * gpiochip_find() - iterator for locating a specific gpio_chip
1598 * @data: data to pass to match function
1599 * @match: Callback function to check gpio_chip
1601 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1602 * determined by a user supplied @match callback. The callback should return
1603 * 0 if the device doesn't match and non-zero if it does. If the callback is
1604 * non-zero, this function will return to the caller and not iterate over any
1607 struct gpio_chip *gpiochip_find(void *data,
1608 int (*match)(struct gpio_chip *chip,
1611 struct gpio_device *gdev;
1612 struct gpio_chip *chip = NULL;
1613 unsigned long flags;
1615 spin_lock_irqsave(&gpio_lock, flags);
1616 list_for_each_entry(gdev, &gpio_devices, list)
1617 if (gdev->chip && match(gdev->chip, data)) {
1622 spin_unlock_irqrestore(&gpio_lock, flags);
1626 EXPORT_SYMBOL_GPL(gpiochip_find);
1628 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1630 const char *name = data;
1632 return !strcmp(chip->label, name);
1635 static struct gpio_chip *find_chip_by_name(const char *name)
1637 return gpiochip_find((void *)name, gpiochip_match_name);
1640 #ifdef CONFIG_GPIOLIB_IRQCHIP
1643 * The following is irqchip helper code for gpiochips.
1646 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1648 if (!gpiochip->irq.need_valid_mask)
1651 gpiochip->irq.valid_mask = gpiochip_allocate_mask(gpiochip);
1652 if (!gpiochip->irq.valid_mask)
1658 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1660 kfree(gpiochip->irq.valid_mask);
1661 gpiochip->irq.valid_mask = NULL;
1664 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1665 unsigned int offset)
1667 if (!gpiochip_line_is_valid(gpiochip, offset))
1669 /* No mask means all valid */
1670 if (likely(!gpiochip->irq.valid_mask))
1672 return test_bit(offset, gpiochip->irq.valid_mask);
1674 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1677 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1678 * @gpiochip: the gpiochip to set the irqchip chain to
1679 * @irqchip: the irqchip to chain to the gpiochip
1680 * @parent_irq: the irq number corresponding to the parent IRQ for this
1682 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1683 * coming out of the gpiochip. If the interrupt is nested rather than
1684 * cascaded, pass NULL in this handler argument
1686 static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
1687 struct irq_chip *irqchip,
1688 unsigned int parent_irq,
1689 irq_flow_handler_t parent_handler)
1691 unsigned int offset;
1693 if (!gpiochip->irq.domain) {
1694 chip_err(gpiochip, "called %s before setting up irqchip\n",
1699 if (parent_handler) {
1700 if (gpiochip->can_sleep) {
1702 "you cannot have chained interrupts on a chip that may sleep\n");
1706 * The parent irqchip is already using the chip_data for this
1707 * irqchip, so our callbacks simply use the handler_data.
1709 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1712 gpiochip->irq.parent_irq = parent_irq;
1713 gpiochip->irq.parents = &gpiochip->irq.parent_irq;
1714 gpiochip->irq.num_parents = 1;
1717 /* Set the parent IRQ for all affected IRQs */
1718 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1719 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1721 irq_set_parent(irq_find_mapping(gpiochip->irq.domain, offset),
1727 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1728 * @gpiochip: the gpiochip to set the irqchip chain to
1729 * @irqchip: the irqchip to chain to the gpiochip
1730 * @parent_irq: the irq number corresponding to the parent IRQ for this
1732 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1733 * coming out of the gpiochip. If the interrupt is nested rather than
1734 * cascaded, pass NULL in this handler argument
1736 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1737 struct irq_chip *irqchip,
1738 unsigned int parent_irq,
1739 irq_flow_handler_t parent_handler)
1741 if (gpiochip->irq.threaded) {
1742 chip_err(gpiochip, "tried to chain a threaded gpiochip\n");
1746 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1749 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1752 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1753 * @gpiochip: the gpiochip to set the irqchip nested handler to
1754 * @irqchip: the irqchip to nest to the gpiochip
1755 * @parent_irq: the irq number corresponding to the parent IRQ for this
1758 void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1759 struct irq_chip *irqchip,
1760 unsigned int parent_irq)
1762 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1765 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1768 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1769 * @d: the irqdomain used by this irqchip
1770 * @irq: the global irq number used by this GPIO irqchip irq
1771 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1773 * This function will set up the mapping for a certain IRQ line on a
1774 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1775 * stored inside the gpiochip.
1777 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1778 irq_hw_number_t hwirq)
1780 struct gpio_chip *chip = d->host_data;
1783 if (!gpiochip_irqchip_irq_valid(chip, hwirq))
1786 irq_set_chip_data(irq, chip);
1788 * This lock class tells lockdep that GPIO irqs are in a different
1789 * category than their parents, so it won't report false recursion.
1791 irq_set_lockdep_class(irq, chip->irq.lock_key, chip->irq.request_key);
1792 irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
1793 /* Chips that use nested thread handlers have them marked */
1794 if (chip->irq.threaded)
1795 irq_set_nested_thread(irq, 1);
1796 irq_set_noprobe(irq);
1798 if (chip->irq.num_parents == 1)
1799 err = irq_set_parent(irq, chip->irq.parents[0]);
1800 else if (chip->irq.map)
1801 err = irq_set_parent(irq, chip->irq.map[hwirq]);
1807 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1808 * is passed as default type.
1810 if (chip->irq.default_type != IRQ_TYPE_NONE)
1811 irq_set_irq_type(irq, chip->irq.default_type);
1815 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1817 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1819 struct gpio_chip *chip = d->host_data;
1821 if (chip->irq.threaded)
1822 irq_set_nested_thread(irq, 0);
1823 irq_set_chip_and_handler(irq, NULL, NULL);
1824 irq_set_chip_data(irq, NULL);
1826 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1828 static const struct irq_domain_ops gpiochip_domain_ops = {
1829 .map = gpiochip_irq_map,
1830 .unmap = gpiochip_irq_unmap,
1831 /* Virtually all GPIO irqchips are twocell:ed */
1832 .xlate = irq_domain_xlate_twocell,
1835 static int gpiochip_irq_reqres(struct irq_data *d)
1837 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1840 if (!try_module_get(chip->gpiodev->owner))
1843 ret = gpiochip_lock_as_irq(chip, d->hwirq);
1846 "unable to lock HW IRQ %lu for IRQ\n",
1848 module_put(chip->gpiodev->owner);
1854 static void gpiochip_irq_relres(struct irq_data *d)
1856 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1858 gpiochip_unlock_as_irq(chip, d->hwirq);
1859 module_put(chip->gpiodev->owner);
1862 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1864 if (!gpiochip_irqchip_irq_valid(chip, offset))
1867 return irq_create_mapping(chip->irq.domain, offset);
1871 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1872 * @gpiochip: the GPIO chip to add the IRQ chip to
1873 * @lock_key: lockdep class for IRQ lock
1874 * @request_key: lockdep class for IRQ request
1876 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
1877 struct lock_class_key *lock_key,
1878 struct lock_class_key *request_key)
1880 struct irq_chip *irqchip = gpiochip->irq.chip;
1881 const struct irq_domain_ops *ops;
1882 struct device_node *np;
1889 if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {
1890 chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n");
1894 np = gpiochip->gpiodev->dev.of_node;
1895 type = gpiochip->irq.default_type;
1898 * Specifying a default trigger is a terrible idea if DT or ACPI is
1899 * used to configure the interrupts, as you may end up with
1900 * conflicting triggers. Tell the user, and reset to NONE.
1902 if (WARN(np && type != IRQ_TYPE_NONE,
1903 "%s: Ignoring %u default trigger\n", np->full_name, type))
1904 type = IRQ_TYPE_NONE;
1906 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1907 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1908 "Ignoring %u default trigger\n", type);
1909 type = IRQ_TYPE_NONE;
1912 gpiochip->to_irq = gpiochip_to_irq;
1913 gpiochip->irq.default_type = type;
1914 gpiochip->irq.lock_key = lock_key;
1915 gpiochip->irq.request_key = request_key;
1917 if (gpiochip->irq.domain_ops)
1918 ops = gpiochip->irq.domain_ops;
1920 ops = &gpiochip_domain_ops;
1922 gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
1923 gpiochip->irq.first,
1925 if (!gpiochip->irq.domain)
1929 * It is possible for a driver to override this, but only if the
1930 * alternative functions are both implemented.
1932 if (!irqchip->irq_request_resources &&
1933 !irqchip->irq_release_resources) {
1934 irqchip->irq_request_resources = gpiochip_irq_reqres;
1935 irqchip->irq_release_resources = gpiochip_irq_relres;
1938 if (gpiochip->irq.parent_handler) {
1939 void *data = gpiochip->irq.parent_handler_data ?: gpiochip;
1941 for (i = 0; i < gpiochip->irq.num_parents; i++) {
1943 * The parent IRQ chip is already using the chip_data
1944 * for this IRQ chip, so our callbacks simply use the
1947 irq_set_chained_handler_and_data(gpiochip->irq.parents[i],
1948 gpiochip->irq.parent_handler,
1953 acpi_gpiochip_request_interrupts(gpiochip);
1959 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1960 * @gpiochip: the gpiochip to remove the irqchip from
1962 * This is called only from gpiochip_remove()
1964 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1966 unsigned int offset;
1968 acpi_gpiochip_free_interrupts(gpiochip);
1970 if (gpiochip->irq.chip && gpiochip->irq.parent_handler) {
1971 struct gpio_irq_chip *irq = &gpiochip->irq;
1974 for (i = 0; i < irq->num_parents; i++)
1975 irq_set_chained_handler_and_data(irq->parents[i],
1979 /* Remove all IRQ mappings and delete the domain */
1980 if (gpiochip->irq.domain) {
1983 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1984 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1987 irq = irq_find_mapping(gpiochip->irq.domain, offset);
1988 irq_dispose_mapping(irq);
1991 irq_domain_remove(gpiochip->irq.domain);
1994 if (gpiochip->irq.chip) {
1995 gpiochip->irq.chip->irq_request_resources = NULL;
1996 gpiochip->irq.chip->irq_release_resources = NULL;
1997 gpiochip->irq.chip = NULL;
2000 gpiochip_irqchip_free_valid_mask(gpiochip);
2004 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
2005 * @gpiochip: the gpiochip to add the irqchip to
2006 * @irqchip: the irqchip to add to the gpiochip
2007 * @first_irq: if not dynamically assigned, the base (first) IRQ to
2008 * allocate gpiochip irqs from
2009 * @handler: the irq handler to use (often a predefined irq core function)
2010 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
2011 * to have the core avoid setting up any default type in the hardware.
2012 * @threaded: whether this irqchip uses a nested thread handler
2013 * @lock_key: lockdep class for IRQ lock
2014 * @request_key: lockdep class for IRQ request
2016 * This function closely associates a certain irqchip with a certain
2017 * gpiochip, providing an irq domain to translate the local IRQs to
2018 * global irqs in the gpiolib core, and making sure that the gpiochip
2019 * is passed as chip data to all related functions. Driver callbacks
2020 * need to use gpiochip_get_data() to get their local state containers back
2021 * from the gpiochip passed as chip data. An irqdomain will be stored
2022 * in the gpiochip that shall be used by the driver to handle IRQ number
2023 * translation. The gpiochip will need to be initialized and registered
2024 * before calling this function.
2026 * This function will handle two cell:ed simple IRQs and assumes all
2027 * the pins on the gpiochip can generate a unique IRQ. Everything else
2028 * need to be open coded.
2030 int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
2031 struct irq_chip *irqchip,
2032 unsigned int first_irq,
2033 irq_flow_handler_t handler,
2036 struct lock_class_key *lock_key,
2037 struct lock_class_key *request_key)
2039 struct device_node *of_node;
2041 if (!gpiochip || !irqchip)
2044 if (!gpiochip->parent) {
2045 pr_err("missing gpiochip .dev parent pointer\n");
2048 gpiochip->irq.threaded = threaded;
2049 of_node = gpiochip->parent->of_node;
2050 #ifdef CONFIG_OF_GPIO
2052 * If the gpiochip has an assigned OF node this takes precedence
2053 * FIXME: get rid of this and use gpiochip->parent->of_node
2056 if (gpiochip->of_node)
2057 of_node = gpiochip->of_node;
2060 * Specifying a default trigger is a terrible idea if DT or ACPI is
2061 * used to configure the interrupts, as you may end-up with
2062 * conflicting triggers. Tell the user, and reset to NONE.
2064 if (WARN(of_node && type != IRQ_TYPE_NONE,
2065 "%pOF: Ignoring %d default trigger\n", of_node, type))
2066 type = IRQ_TYPE_NONE;
2067 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
2068 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
2069 "Ignoring %d default trigger\n", type);
2070 type = IRQ_TYPE_NONE;
2073 gpiochip->irq.chip = irqchip;
2074 gpiochip->irq.handler = handler;
2075 gpiochip->irq.default_type = type;
2076 gpiochip->to_irq = gpiochip_to_irq;
2077 gpiochip->irq.lock_key = lock_key;
2078 gpiochip->irq.request_key = request_key;
2079 gpiochip->irq.domain = irq_domain_add_simple(of_node,
2080 gpiochip->ngpio, first_irq,
2081 &gpiochip_domain_ops, gpiochip);
2082 if (!gpiochip->irq.domain) {
2083 gpiochip->irq.chip = NULL;
2088 * It is possible for a driver to override this, but only if the
2089 * alternative functions are both implemented.
2091 if (!irqchip->irq_request_resources &&
2092 !irqchip->irq_release_resources) {
2093 irqchip->irq_request_resources = gpiochip_irq_reqres;
2094 irqchip->irq_release_resources = gpiochip_irq_relres;
2097 acpi_gpiochip_request_interrupts(gpiochip);
2101 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
2103 #else /* CONFIG_GPIOLIB_IRQCHIP */
2105 static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
2106 struct lock_class_key *lock_key,
2107 struct lock_class_key *request_key)
2112 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
2113 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
2117 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
2120 #endif /* CONFIG_GPIOLIB_IRQCHIP */
2123 * gpiochip_generic_request() - request the gpio function for a pin
2124 * @chip: the gpiochip owning the GPIO
2125 * @offset: the offset of the GPIO to request for GPIO function
2127 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
2129 return pinctrl_gpio_request(chip->gpiodev->base + offset);
2131 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2134 * gpiochip_generic_free() - free the gpio function from a pin
2135 * @chip: the gpiochip to request the gpio function for
2136 * @offset: the offset of the GPIO to free from GPIO function
2138 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
2140 pinctrl_gpio_free(chip->gpiodev->base + offset);
2142 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2145 * gpiochip_generic_config() - apply configuration for a pin
2146 * @chip: the gpiochip owning the GPIO
2147 * @offset: the offset of the GPIO to apply the configuration
2148 * @config: the configuration to be applied
2150 int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
2151 unsigned long config)
2153 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
2155 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2157 #ifdef CONFIG_PINCTRL
2160 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2161 * @chip: the gpiochip to add the range for
2162 * @pctldev: the pin controller to map to
2163 * @gpio_offset: the start offset in the current gpio_chip number space
2164 * @pin_group: name of the pin group inside the pin controller
2166 * Calling this function directly from a DeviceTree-supported
2167 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2168 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2169 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2171 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
2172 struct pinctrl_dev *pctldev,
2173 unsigned int gpio_offset, const char *pin_group)
2175 struct gpio_pin_range *pin_range;
2176 struct gpio_device *gdev = chip->gpiodev;
2179 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2181 chip_err(chip, "failed to allocate pin ranges\n");
2185 /* Use local offset as range ID */
2186 pin_range->range.id = gpio_offset;
2187 pin_range->range.gc = chip;
2188 pin_range->range.name = chip->label;
2189 pin_range->range.base = gdev->base + gpio_offset;
2190 pin_range->pctldev = pctldev;
2192 ret = pinctrl_get_group_pins(pctldev, pin_group,
2193 &pin_range->range.pins,
2194 &pin_range->range.npins);
2200 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2202 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2203 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2204 pinctrl_dev_get_devname(pctldev), pin_group);
2206 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2210 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2213 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2214 * @chip: the gpiochip to add the range for
2215 * @pinctl_name: the dev_name() of the pin controller to map to
2216 * @gpio_offset: the start offset in the current gpio_chip number space
2217 * @pin_offset: the start offset in the pin controller number space
2218 * @npins: the number of pins from the offset of each pin space (GPIO and
2219 * pin controller) to accumulate in this range
2222 * 0 on success, or a negative error-code on failure.
2224 * Calling this function directly from a DeviceTree-supported
2225 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2226 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2227 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2229 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
2230 unsigned int gpio_offset, unsigned int pin_offset,
2233 struct gpio_pin_range *pin_range;
2234 struct gpio_device *gdev = chip->gpiodev;
2237 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2239 chip_err(chip, "failed to allocate pin ranges\n");
2243 /* Use local offset as range ID */
2244 pin_range->range.id = gpio_offset;
2245 pin_range->range.gc = chip;
2246 pin_range->range.name = chip->label;
2247 pin_range->range.base = gdev->base + gpio_offset;
2248 pin_range->range.pin_base = pin_offset;
2249 pin_range->range.npins = npins;
2250 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2252 if (IS_ERR(pin_range->pctldev)) {
2253 ret = PTR_ERR(pin_range->pctldev);
2254 chip_err(chip, "could not create pin range\n");
2258 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2259 gpio_offset, gpio_offset + npins - 1,
2261 pin_offset, pin_offset + npins - 1);
2263 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2267 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2270 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2271 * @chip: the chip to remove all the mappings for
2273 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
2275 struct gpio_pin_range *pin_range, *tmp;
2276 struct gpio_device *gdev = chip->gpiodev;
2278 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2279 list_del(&pin_range->node);
2280 pinctrl_remove_gpio_range(pin_range->pctldev,
2285 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2287 #endif /* CONFIG_PINCTRL */
2289 /* These "optional" allocation calls help prevent drivers from stomping
2290 * on each other, and help provide better diagnostics in debugfs.
2291 * They're called even less than the "set direction" calls.
2293 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2295 struct gpio_chip *chip = desc->gdev->chip;
2297 unsigned long flags;
2301 label = kstrdup_const(label, GFP_KERNEL);
2306 spin_lock_irqsave(&gpio_lock, flags);
2308 /* NOTE: gpio_request() can be called in early boot,
2309 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2312 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2313 desc_set_label(desc, label ? : "?");
2321 if (chip->request) {
2322 /* chip->request may sleep */
2323 spin_unlock_irqrestore(&gpio_lock, flags);
2324 offset = gpio_chip_hwgpio(desc);
2325 if (gpiochip_line_is_valid(chip, offset))
2326 status = chip->request(chip, offset);
2329 spin_lock_irqsave(&gpio_lock, flags);
2332 desc_set_label(desc, NULL);
2334 clear_bit(FLAG_REQUESTED, &desc->flags);
2338 if (chip->get_direction) {
2339 /* chip->get_direction may sleep */
2340 spin_unlock_irqrestore(&gpio_lock, flags);
2341 gpiod_get_direction(desc);
2342 spin_lock_irqsave(&gpio_lock, flags);
2345 spin_unlock_irqrestore(&gpio_lock, flags);
2350 * This descriptor validation needs to be inserted verbatim into each
2351 * function taking a descriptor, so we need to use a preprocessor
2352 * macro to avoid endless duplication. If the desc is NULL it is an
2353 * optional GPIO and calls should just bail out.
2355 static int validate_desc(const struct gpio_desc *desc, const char *func)
2360 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2361 return PTR_ERR(desc);
2364 pr_warn("%s: invalid GPIO (no device)\n", func);
2367 if (!desc->gdev->chip) {
2368 dev_warn(&desc->gdev->dev,
2369 "%s: backing chip is gone\n", func);
2375 #define VALIDATE_DESC(desc) do { \
2376 int __valid = validate_desc(desc, __func__); \
2381 #define VALIDATE_DESC_VOID(desc) do { \
2382 int __valid = validate_desc(desc, __func__); \
2387 int gpiod_request(struct gpio_desc *desc, const char *label)
2389 int status = -EPROBE_DEFER;
2390 struct gpio_device *gdev;
2392 VALIDATE_DESC(desc);
2395 if (try_module_get(gdev->owner)) {
2396 status = gpiod_request_commit(desc, label);
2398 module_put(gdev->owner);
2400 get_device(&gdev->dev);
2404 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2409 static bool gpiod_free_commit(struct gpio_desc *desc)
2412 unsigned long flags;
2413 struct gpio_chip *chip;
2417 gpiod_unexport(desc);
2419 spin_lock_irqsave(&gpio_lock, flags);
2421 chip = desc->gdev->chip;
2422 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2424 spin_unlock_irqrestore(&gpio_lock, flags);
2425 might_sleep_if(chip->can_sleep);
2426 chip->free(chip, gpio_chip_hwgpio(desc));
2427 spin_lock_irqsave(&gpio_lock, flags);
2429 kfree_const(desc->label);
2430 desc_set_label(desc, NULL);
2431 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2432 clear_bit(FLAG_REQUESTED, &desc->flags);
2433 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2434 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2435 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2439 spin_unlock_irqrestore(&gpio_lock, flags);
2443 void gpiod_free(struct gpio_desc *desc)
2445 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2446 module_put(desc->gdev->owner);
2447 put_device(&desc->gdev->dev);
2449 WARN_ON(extra_checks);
2454 * gpiochip_is_requested - return string iff signal was requested
2455 * @chip: controller managing the signal
2456 * @offset: of signal within controller's 0..(ngpio - 1) range
2458 * Returns NULL if the GPIO is not currently requested, else a string.
2459 * The string returned is the label passed to gpio_request(); if none has been
2460 * passed it is a meaningless, non-NULL constant.
2462 * This function is for use by GPIO controller drivers. The label can
2463 * help with diagnostics, and knowing that the signal is used as a GPIO
2464 * can help avoid accidentally multiplexing it to another controller.
2466 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2468 struct gpio_desc *desc;
2470 if (offset >= chip->ngpio)
2473 desc = &chip->gpiodev->descs[offset];
2475 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2479 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2482 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2484 * @hwnum: hardware number of the GPIO for which to request the descriptor
2485 * @label: label for the GPIO
2487 * Function allows GPIO chip drivers to request and use their own GPIO
2488 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2489 * function will not increase reference count of the GPIO chip module. This
2490 * allows the GPIO chip module to be unloaded as needed (we assume that the
2491 * GPIO chip driver handles freeing the GPIOs it has requested).
2494 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2497 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2500 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2504 chip_err(chip, "failed to get GPIO descriptor\n");
2508 err = gpiod_request_commit(desc, label);
2510 return ERR_PTR(err);
2514 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2517 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2518 * @desc: GPIO descriptor to free
2520 * Function frees the given GPIO requested previously with
2521 * gpiochip_request_own_desc().
2523 void gpiochip_free_own_desc(struct gpio_desc *desc)
2526 gpiod_free_commit(desc);
2528 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2531 * Drivers MUST set GPIO direction before making get/set calls. In
2532 * some cases this is done in early boot, before IRQs are enabled.
2534 * As a rule these aren't called more than once (except for drivers
2535 * using the open-drain emulation idiom) so these are natural places
2536 * to accumulate extra debugging checks. Note that we can't (yet)
2537 * rely on gpio_request() having been called beforehand.
2541 * gpiod_direction_input - set the GPIO direction to input
2542 * @desc: GPIO to set to input
2544 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2545 * be called safely on it.
2547 * Return 0 in case of success, else an error code.
2549 int gpiod_direction_input(struct gpio_desc *desc)
2551 struct gpio_chip *chip;
2554 VALIDATE_DESC(desc);
2555 chip = desc->gdev->chip;
2557 if (!chip->get && chip->direction_input) {
2559 "%s: missing get() and direction_input() operations\n",
2564 if (chip->direction_input) {
2565 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2566 } else if (chip->get_direction &&
2567 (chip->get_direction(chip, gpio_chip_hwgpio(desc)) != 1)) {
2569 "%s: missing direction_input() operation\n",
2574 clear_bit(FLAG_IS_OUT, &desc->flags);
2576 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2580 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2582 static int gpio_set_drive_single_ended(struct gpio_chip *gc, unsigned offset,
2583 enum pin_config_param mode)
2585 unsigned long config = { PIN_CONF_PACKED(mode, 0) };
2587 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2590 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2592 struct gpio_chip *gc = desc->gdev->chip;
2596 if (!gc->set && !gc->direction_output) {
2598 "%s: missing set() and direction_output() operations\n",
2603 if (gc->direction_output) {
2604 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2606 if (gc->get_direction &&
2607 gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
2609 "%s: missing direction_output() operation\n",
2613 gc->set(gc, gpio_chip_hwgpio(desc), val);
2617 set_bit(FLAG_IS_OUT, &desc->flags);
2618 trace_gpio_value(desc_to_gpio(desc), 0, val);
2619 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2624 * gpiod_direction_output_raw - set the GPIO direction to output
2625 * @desc: GPIO to set to output
2626 * @value: initial output value of the GPIO
2628 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2629 * be called safely on it. The initial value of the output must be specified
2630 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2632 * Return 0 in case of success, else an error code.
2634 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2636 VALIDATE_DESC(desc);
2637 return gpiod_direction_output_raw_commit(desc, value);
2639 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2642 * gpiod_direction_output - set the GPIO direction to output
2643 * @desc: GPIO to set to output
2644 * @value: initial output value of the GPIO
2646 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2647 * be called safely on it. The initial value of the output must be specified
2648 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2651 * Return 0 in case of success, else an error code.
2653 int gpiod_direction_output(struct gpio_desc *desc, int value)
2655 struct gpio_chip *gc;
2658 VALIDATE_DESC(desc);
2659 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2664 /* GPIOs used for IRQs shall not be set as output */
2665 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
2667 "%s: tried to set a GPIO tied to an IRQ as output\n",
2672 gc = desc->gdev->chip;
2673 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2674 /* First see if we can enable open drain in hardware */
2675 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2676 PIN_CONFIG_DRIVE_OPEN_DRAIN);
2678 goto set_output_value;
2679 /* Emulate open drain by not actively driving the line high */
2681 ret = gpiod_direction_input(desc);
2682 goto set_output_flag;
2685 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2686 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2687 PIN_CONFIG_DRIVE_OPEN_SOURCE);
2689 goto set_output_value;
2690 /* Emulate open source by not actively driving the line low */
2692 ret = gpiod_direction_input(desc);
2693 goto set_output_flag;
2696 gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2697 PIN_CONFIG_DRIVE_PUSH_PULL);
2701 return gpiod_direction_output_raw_commit(desc, value);
2705 * When emulating open-source or open-drain functionalities by not
2706 * actively driving the line (setting mode to input) we still need to
2707 * set the IS_OUT flag or otherwise we won't be able to set the line
2711 set_bit(FLAG_IS_OUT, &desc->flags);
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,
2863 while (i < array_size) {
2864 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2865 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
2866 unsigned long *mask, *bits;
2869 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
2872 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
2874 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
2879 bits = mask + BITS_TO_LONGS(chip->ngpio);
2880 bitmap_zero(mask, chip->ngpio);
2883 WARN_ON(chip->can_sleep);
2885 /* collect all inputs belonging to the same chip */
2888 const struct gpio_desc *desc = desc_array[i];
2889 int hwgpio = gpio_chip_hwgpio(desc);
2891 __set_bit(hwgpio, mask);
2893 } while ((i < array_size) &&
2894 (desc_array[i]->gdev->chip == chip));
2896 ret = gpio_chip_get_multiple(chip, mask, bits);
2898 if (mask != fastpath)
2903 for (j = first; j < i; j++) {
2904 const struct gpio_desc *desc = desc_array[j];
2905 int hwgpio = gpio_chip_hwgpio(desc);
2906 int value = test_bit(hwgpio, bits);
2908 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2910 value_array[j] = value;
2911 trace_gpio_value(desc_to_gpio(desc), 1, value);
2914 if (mask != fastpath)
2921 * gpiod_get_raw_value() - return a gpio's raw value
2922 * @desc: gpio whose value will be returned
2924 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2925 * its ACTIVE_LOW status, or negative errno on failure.
2927 * This function should be called from contexts where we cannot sleep, and will
2928 * complain if the GPIO chip functions potentially sleep.
2930 int gpiod_get_raw_value(const struct gpio_desc *desc)
2932 VALIDATE_DESC(desc);
2933 /* Should be using gpiod_get_raw_value_cansleep() */
2934 WARN_ON(desc->gdev->chip->can_sleep);
2935 return gpiod_get_raw_value_commit(desc);
2937 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2940 * gpiod_get_value() - return a gpio's value
2941 * @desc: gpio whose value will be returned
2943 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2944 * account, or negative errno on failure.
2946 * This function should be called from contexts where we cannot sleep, and will
2947 * complain if the GPIO chip functions potentially sleep.
2949 int gpiod_get_value(const struct gpio_desc *desc)
2953 VALIDATE_DESC(desc);
2954 /* Should be using gpiod_get_value_cansleep() */
2955 WARN_ON(desc->gdev->chip->can_sleep);
2957 value = gpiod_get_raw_value_commit(desc);
2961 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2966 EXPORT_SYMBOL_GPL(gpiod_get_value);
2969 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
2970 * @array_size: number of elements in the descriptor / value arrays
2971 * @desc_array: array of GPIO descriptors whose values will be read
2972 * @value_array: array to store the read values
2974 * Read the raw values of the GPIOs, i.e. the values of the physical lines
2975 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
2976 * else an error code.
2978 * This function should be called from contexts where we cannot sleep,
2979 * and it will complain if the GPIO chip functions potentially sleep.
2981 int gpiod_get_raw_array_value(unsigned int array_size,
2982 struct gpio_desc **desc_array, int *value_array)
2986 return gpiod_get_array_value_complex(true, false, array_size,
2987 desc_array, value_array);
2989 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
2992 * gpiod_get_array_value() - read values from an array of GPIOs
2993 * @array_size: number of elements in the descriptor / value arrays
2994 * @desc_array: array of GPIO descriptors whose values will be read
2995 * @value_array: array to store the read values
2997 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2998 * into account. Return 0 in case of success, else an error code.
3000 * This function should be called from contexts where we cannot sleep,
3001 * and it will complain if the GPIO chip functions potentially sleep.
3003 int gpiod_get_array_value(unsigned int array_size,
3004 struct gpio_desc **desc_array, int *value_array)
3008 return gpiod_get_array_value_complex(false, false, array_size,
3009 desc_array, value_array);
3011 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
3014 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
3015 * @desc: gpio descriptor whose state need to be set.
3016 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3018 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
3021 struct gpio_chip *chip = desc->gdev->chip;
3022 int offset = gpio_chip_hwgpio(desc);
3025 err = chip->direction_input(chip, offset);
3027 err = chip->direction_output(chip, offset, 0);
3029 set_bit(FLAG_IS_OUT, &desc->flags);
3031 trace_gpio_direction(desc_to_gpio(desc), value, err);
3034 "%s: Error in set_value for open drain err %d\n",
3039 * _gpio_set_open_source_value() - Set the open source gpio's value.
3040 * @desc: gpio descriptor whose state need to be set.
3041 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3043 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
3046 struct gpio_chip *chip = desc->gdev->chip;
3047 int offset = gpio_chip_hwgpio(desc);
3050 err = chip->direction_output(chip, offset, 1);
3052 set_bit(FLAG_IS_OUT, &desc->flags);
3054 err = chip->direction_input(chip, offset);
3056 trace_gpio_direction(desc_to_gpio(desc), !value, err);
3059 "%s: Error in set_value for open source err %d\n",
3063 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
3065 struct gpio_chip *chip;
3067 chip = desc->gdev->chip;
3068 trace_gpio_value(desc_to_gpio(desc), 0, value);
3069 chip->set(chip, gpio_chip_hwgpio(desc), value);
3073 * set multiple outputs on the same chip;
3074 * use the chip's set_multiple function if available;
3075 * otherwise set the outputs sequentially;
3076 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3077 * defines which outputs are to be changed
3078 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3079 * defines the values the outputs specified by mask are to be set to
3081 static void gpio_chip_set_multiple(struct gpio_chip *chip,
3082 unsigned long *mask, unsigned long *bits)
3084 if (chip->set_multiple) {
3085 chip->set_multiple(chip, mask, bits);
3089 /* set outputs if the corresponding mask bit is set */
3090 for_each_set_bit(i, mask, chip->ngpio)
3091 chip->set(chip, i, test_bit(i, bits));
3095 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3096 unsigned int array_size,
3097 struct gpio_desc **desc_array,
3102 while (i < array_size) {
3103 struct gpio_chip *chip = desc_array[i]->gdev->chip;
3104 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
3105 unsigned long *mask, *bits;
3108 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
3111 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
3113 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
3118 bits = mask + BITS_TO_LONGS(chip->ngpio);
3119 bitmap_zero(mask, chip->ngpio);
3122 WARN_ON(chip->can_sleep);
3125 struct gpio_desc *desc = desc_array[i];
3126 int hwgpio = gpio_chip_hwgpio(desc);
3127 int value = value_array[i];
3129 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3131 trace_gpio_value(desc_to_gpio(desc), 0, value);
3133 * collect all normal outputs belonging to the same chip
3134 * open drain and open source outputs are set individually
3136 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3137 gpio_set_open_drain_value_commit(desc, value);
3138 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3139 gpio_set_open_source_value_commit(desc, value);
3141 __set_bit(hwgpio, mask);
3143 __set_bit(hwgpio, bits);
3145 __clear_bit(hwgpio, bits);
3149 } while ((i < array_size) &&
3150 (desc_array[i]->gdev->chip == chip));
3151 /* push collected bits to outputs */
3153 gpio_chip_set_multiple(chip, mask, bits);
3155 if (mask != fastpath)
3162 * gpiod_set_raw_value() - assign a gpio's raw value
3163 * @desc: gpio whose value will be assigned
3164 * @value: value to assign
3166 * Set the raw value of the GPIO, i.e. the value of its physical line without
3167 * regard for its ACTIVE_LOW status.
3169 * This function should be called from contexts where we cannot sleep, and will
3170 * complain if the GPIO chip functions potentially sleep.
3172 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3174 VALIDATE_DESC_VOID(desc);
3175 /* Should be using gpiod_set_raw_value_cansleep() */
3176 WARN_ON(desc->gdev->chip->can_sleep);
3177 gpiod_set_raw_value_commit(desc, value);
3179 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3182 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3183 * @desc: the descriptor to set the value on
3184 * @value: value to set
3186 * This sets the value of a GPIO line backing a descriptor, applying
3187 * different semantic quirks like active low and open drain/source
3190 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3192 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3194 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3195 gpio_set_open_drain_value_commit(desc, value);
3196 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3197 gpio_set_open_source_value_commit(desc, value);
3199 gpiod_set_raw_value_commit(desc, value);
3203 * gpiod_set_value() - assign a gpio's value
3204 * @desc: gpio whose value will be assigned
3205 * @value: value to assign
3207 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3208 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3210 * This function should be called from contexts where we cannot sleep, and will
3211 * complain if the GPIO chip functions potentially sleep.
3213 void gpiod_set_value(struct gpio_desc *desc, int value)
3215 VALIDATE_DESC_VOID(desc);
3216 /* Should be using gpiod_set_value_cansleep() */
3217 WARN_ON(desc->gdev->chip->can_sleep);
3218 gpiod_set_value_nocheck(desc, value);
3220 EXPORT_SYMBOL_GPL(gpiod_set_value);
3223 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3224 * @array_size: number of elements in the descriptor / value arrays
3225 * @desc_array: array of GPIO descriptors whose values will be assigned
3226 * @value_array: array of values to assign
3228 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3229 * without regard for their ACTIVE_LOW status.
3231 * This function should be called from contexts where we cannot sleep, and will
3232 * complain if the GPIO chip functions potentially sleep.
3234 int gpiod_set_raw_array_value(unsigned int array_size,
3235 struct gpio_desc **desc_array, int *value_array)
3239 return gpiod_set_array_value_complex(true, false, array_size,
3240 desc_array, value_array);
3242 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3245 * gpiod_set_array_value() - assign values to an array of GPIOs
3246 * @array_size: number of elements in the descriptor / value arrays
3247 * @desc_array: array of GPIO descriptors whose values will be assigned
3248 * @value_array: array of values to assign
3250 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3253 * This function should be called from contexts where we cannot sleep, and will
3254 * complain if the GPIO chip functions potentially sleep.
3256 void gpiod_set_array_value(unsigned int array_size,
3257 struct gpio_desc **desc_array, int *value_array)
3261 gpiod_set_array_value_complex(false, false, array_size, desc_array,
3264 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3267 * gpiod_cansleep() - report whether gpio value access may sleep
3268 * @desc: gpio to check
3271 int gpiod_cansleep(const struct gpio_desc *desc)
3273 VALIDATE_DESC(desc);
3274 return desc->gdev->chip->can_sleep;
3276 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3279 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3280 * @desc: gpio to set the consumer name on
3281 * @name: the new consumer name
3283 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3285 VALIDATE_DESC(desc);
3287 name = kstrdup_const(name, GFP_KERNEL);
3292 kfree_const(desc->label);
3293 desc_set_label(desc, name);
3297 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3300 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3301 * @desc: gpio whose IRQ will be returned (already requested)
3303 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3306 int gpiod_to_irq(const struct gpio_desc *desc)
3308 struct gpio_chip *chip;
3312 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3313 * requires this function to not return zero on an invalid descriptor
3314 * but rather a negative error number.
3316 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3319 chip = desc->gdev->chip;
3320 offset = gpio_chip_hwgpio(desc);
3322 int retirq = chip->to_irq(chip, offset);
3324 /* Zero means NO_IRQ */
3332 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3335 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3336 * @chip: the chip the GPIO to lock belongs to
3337 * @offset: the offset of the GPIO to lock as IRQ
3339 * This is used directly by GPIO drivers that want to lock down
3340 * a certain GPIO line to be used for IRQs.
3342 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
3344 struct gpio_desc *desc;
3346 desc = gpiochip_get_desc(chip, offset);
3348 return PTR_ERR(desc);
3351 * If it's fast: flush the direction setting if something changed
3354 if (!chip->can_sleep && chip->get_direction) {
3355 int dir = gpiod_get_direction(desc);
3358 chip_err(chip, "%s: cannot get GPIO direction\n",
3364 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
3366 "%s: tried to flag a GPIO set as output for IRQ\n",
3371 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3374 * If the consumer has not set up a label (such as when the
3375 * IRQ is referenced from .to_irq()) we set up a label here
3376 * so it is clear this is used as an interrupt.
3379 desc_set_label(desc, "interrupt");
3383 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3386 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3387 * @chip: the chip the GPIO to lock belongs to
3388 * @offset: the offset of the GPIO to lock as IRQ
3390 * This is used directly by GPIO drivers that want to indicate
3391 * that a certain GPIO is no longer used exclusively for IRQ.
3393 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
3395 struct gpio_desc *desc;
3397 desc = gpiochip_get_desc(chip, offset);
3401 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3403 /* If we only had this marking, erase it */
3404 if (desc->label && !strcmp(desc->label, "interrupt"))
3405 desc_set_label(desc, NULL);
3407 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3409 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
3411 if (offset >= chip->ngpio)
3414 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
3416 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3418 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
3420 if (offset >= chip->ngpio)
3423 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
3425 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3427 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
3429 if (offset >= chip->ngpio)
3432 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
3434 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3436 bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
3438 if (offset >= chip->ngpio)
3441 return !test_bit(FLAG_TRANSITORY, &chip->gpiodev->descs[offset].flags);
3443 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3446 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3447 * @desc: gpio whose value will be returned
3449 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3450 * its ACTIVE_LOW status, or negative errno on failure.
3452 * This function is to be called from contexts that can sleep.
3454 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3456 might_sleep_if(extra_checks);
3457 VALIDATE_DESC(desc);
3458 return gpiod_get_raw_value_commit(desc);
3460 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3463 * gpiod_get_value_cansleep() - return a gpio's value
3464 * @desc: gpio whose value will be returned
3466 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3467 * account, or negative errno on failure.
3469 * This function is to be called from contexts that can sleep.
3471 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3475 might_sleep_if(extra_checks);
3476 VALIDATE_DESC(desc);
3477 value = gpiod_get_raw_value_commit(desc);
3481 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3486 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3489 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3490 * @array_size: number of elements in the descriptor / value arrays
3491 * @desc_array: array of GPIO descriptors whose values will be read
3492 * @value_array: array to store the read values
3494 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3495 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3496 * else an error code.
3498 * This function is to be called from contexts that can sleep.
3500 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3501 struct gpio_desc **desc_array,
3504 might_sleep_if(extra_checks);
3507 return gpiod_get_array_value_complex(true, true, array_size,
3508 desc_array, value_array);
3510 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3513 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3514 * @array_size: number of elements in the descriptor / value arrays
3515 * @desc_array: array of GPIO descriptors whose values will be read
3516 * @value_array: array to store the read values
3518 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3519 * into account. Return 0 in case of success, else an error code.
3521 * This function is to be called from contexts that can sleep.
3523 int gpiod_get_array_value_cansleep(unsigned int array_size,
3524 struct gpio_desc **desc_array,
3527 might_sleep_if(extra_checks);
3530 return gpiod_get_array_value_complex(false, true, array_size,
3531 desc_array, value_array);
3533 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3536 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3537 * @desc: gpio whose value will be assigned
3538 * @value: value to assign
3540 * Set the raw value of the GPIO, i.e. the value of its physical line without
3541 * regard for its ACTIVE_LOW status.
3543 * This function is to be called from contexts that can sleep.
3545 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3547 might_sleep_if(extra_checks);
3548 VALIDATE_DESC_VOID(desc);
3549 gpiod_set_raw_value_commit(desc, value);
3551 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3554 * gpiod_set_value_cansleep() - assign a gpio's value
3555 * @desc: gpio whose value will be assigned
3556 * @value: value to assign
3558 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3561 * This function is to be called from contexts that can sleep.
3563 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3565 might_sleep_if(extra_checks);
3566 VALIDATE_DESC_VOID(desc);
3567 gpiod_set_value_nocheck(desc, value);
3569 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3572 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3573 * @array_size: number of elements in the descriptor / value arrays
3574 * @desc_array: array of GPIO descriptors whose values will be assigned
3575 * @value_array: array of values to assign
3577 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3578 * without regard for their ACTIVE_LOW status.
3580 * This function is to be called from contexts that can sleep.
3582 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3583 struct gpio_desc **desc_array,
3586 might_sleep_if(extra_checks);
3589 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3592 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3595 * gpiod_add_lookup_tables() - register GPIO device consumers
3596 * @tables: list of tables of consumers to register
3597 * @n: number of tables in the list
3599 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3603 mutex_lock(&gpio_lookup_lock);
3605 for (i = 0; i < n; i++)
3606 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3608 mutex_unlock(&gpio_lookup_lock);
3612 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3613 * @array_size: number of elements in the descriptor / value arrays
3614 * @desc_array: array of GPIO descriptors whose values will be assigned
3615 * @value_array: array of values to assign
3617 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3620 * This function is to be called from contexts that can sleep.
3622 void gpiod_set_array_value_cansleep(unsigned int array_size,
3623 struct gpio_desc **desc_array,
3626 might_sleep_if(extra_checks);
3629 gpiod_set_array_value_complex(false, true, array_size, desc_array,
3632 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3635 * gpiod_add_lookup_table() - register GPIO device consumers
3636 * @table: table of consumers to register
3638 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3640 mutex_lock(&gpio_lookup_lock);
3642 list_add_tail(&table->list, &gpio_lookup_list);
3644 mutex_unlock(&gpio_lookup_lock);
3646 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3649 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3650 * @table: table of consumers to unregister
3652 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3654 mutex_lock(&gpio_lookup_lock);
3656 list_del(&table->list);
3658 mutex_unlock(&gpio_lookup_lock);
3660 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3663 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
3664 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
3666 void gpiod_add_hogs(struct gpiod_hog *hogs)
3668 struct gpio_chip *chip;
3669 struct gpiod_hog *hog;
3671 mutex_lock(&gpio_machine_hogs_mutex);
3673 for (hog = &hogs[0]; hog->chip_label; hog++) {
3674 list_add_tail(&hog->list, &gpio_machine_hogs);
3677 * The chip may have been registered earlier, so check if it
3678 * exists and, if so, try to hog the line now.
3680 chip = find_chip_by_name(hog->chip_label);
3682 gpiochip_machine_hog(chip, hog);
3685 mutex_unlock(&gpio_machine_hogs_mutex);
3687 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
3689 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3691 const char *dev_id = dev ? dev_name(dev) : NULL;
3692 struct gpiod_lookup_table *table;
3694 mutex_lock(&gpio_lookup_lock);
3696 list_for_each_entry(table, &gpio_lookup_list, list) {
3697 if (table->dev_id && dev_id) {
3699 * Valid strings on both ends, must be identical to have
3702 if (!strcmp(table->dev_id, dev_id))
3706 * One of the pointers is NULL, so both must be to have
3709 if (dev_id == table->dev_id)
3716 mutex_unlock(&gpio_lookup_lock);
3720 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3722 enum gpio_lookup_flags *flags)
3724 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3725 struct gpiod_lookup_table *table;
3726 struct gpiod_lookup *p;
3728 table = gpiod_find_lookup_table(dev);
3732 for (p = &table->table[0]; p->chip_label; p++) {
3733 struct gpio_chip *chip;
3735 /* idx must always match exactly */
3739 /* If the lookup entry has a con_id, require exact match */
3740 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3743 chip = find_chip_by_name(p->chip_label);
3747 * As the lookup table indicates a chip with
3748 * p->chip_label should exist, assume it may
3749 * still appear later and let the interested
3750 * consumer be probed again or let the Deferred
3751 * Probe infrastructure handle the error.
3753 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
3755 return ERR_PTR(-EPROBE_DEFER);
3758 if (chip->ngpio <= p->chip_hwnum) {
3760 "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
3761 idx, p->chip_hwnum, chip->ngpio - 1,
3763 return ERR_PTR(-EINVAL);
3766 desc = gpiochip_get_desc(chip, p->chip_hwnum);
3775 static int dt_gpio_count(struct device *dev, const char *con_id)
3781 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3783 snprintf(propname, sizeof(propname), "%s-%s",
3784 con_id, gpio_suffixes[i]);
3786 snprintf(propname, sizeof(propname), "%s",
3789 ret = of_gpio_named_count(dev->of_node, propname);
3793 return ret ? ret : -ENOENT;
3796 static int platform_gpio_count(struct device *dev, const char *con_id)
3798 struct gpiod_lookup_table *table;
3799 struct gpiod_lookup *p;
3800 unsigned int count = 0;
3802 table = gpiod_find_lookup_table(dev);
3806 for (p = &table->table[0]; p->chip_label; p++) {
3807 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3808 (!con_id && !p->con_id))
3818 * gpiod_count - return the number of GPIOs associated with a device / function
3819 * or -ENOENT if no GPIO has been assigned to the requested function
3820 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3821 * @con_id: function within the GPIO consumer
3823 int gpiod_count(struct device *dev, const char *con_id)
3825 int count = -ENOENT;
3827 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
3828 count = dt_gpio_count(dev, con_id);
3829 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
3830 count = acpi_gpio_count(dev, con_id);
3833 count = platform_gpio_count(dev, con_id);
3837 EXPORT_SYMBOL_GPL(gpiod_count);
3840 * gpiod_get - obtain a GPIO for a given GPIO function
3841 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3842 * @con_id: function within the GPIO consumer
3843 * @flags: optional GPIO initialization flags
3845 * Return the GPIO descriptor corresponding to the function con_id of device
3846 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3847 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3849 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3850 enum gpiod_flags flags)
3852 return gpiod_get_index(dev, con_id, 0, flags);
3854 EXPORT_SYMBOL_GPL(gpiod_get);
3857 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3858 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3859 * @con_id: function within the GPIO consumer
3860 * @flags: optional GPIO initialization flags
3862 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3863 * the requested function it will return NULL. This is convenient for drivers
3864 * that need to handle optional GPIOs.
3866 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3868 enum gpiod_flags flags)
3870 return gpiod_get_index_optional(dev, con_id, 0, flags);
3872 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3876 * gpiod_configure_flags - helper function to configure a given GPIO
3877 * @desc: gpio whose value will be assigned
3878 * @con_id: function within the GPIO consumer
3879 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3881 * @dflags: gpiod_flags - optional GPIO initialization flags
3883 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3884 * requested function and/or index, or another IS_ERR() code if an error
3885 * occurred while trying to acquire the GPIO.
3887 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3888 unsigned long lflags, enum gpiod_flags dflags)
3892 if (lflags & GPIO_ACTIVE_LOW)
3893 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3895 if (lflags & GPIO_OPEN_DRAIN)
3896 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3897 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
3899 * This enforces open drain mode from the consumer side.
3900 * This is necessary for some busses like I2C, but the lookup
3901 * should *REALLY* have specified them as open drain in the
3902 * first place, so print a little warning here.
3904 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3906 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
3909 if (lflags & GPIO_OPEN_SOURCE)
3910 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3912 status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
3916 /* No particular flag request, return here... */
3917 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3918 pr_debug("no flags found for %s\n", con_id);
3923 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3924 status = gpiod_direction_output(desc,
3925 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3927 status = gpiod_direction_input(desc);
3933 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3934 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3935 * @con_id: function within the GPIO consumer
3936 * @idx: index of the GPIO to obtain in the consumer
3937 * @flags: optional GPIO initialization flags
3939 * This variant of gpiod_get() allows to access GPIOs other than the first
3940 * defined one for functions that define several GPIOs.
3942 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3943 * requested function and/or index, or another IS_ERR() code if an error
3944 * occurred while trying to acquire the GPIO.
3946 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3949 enum gpiod_flags flags)
3951 struct gpio_desc *desc = NULL;
3953 enum gpio_lookup_flags lookupflags = 0;
3954 /* Maybe we have a device name, maybe not */
3955 const char *devname = dev ? dev_name(dev) : "?";
3957 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3960 /* Using device tree? */
3961 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
3962 dev_dbg(dev, "using device tree for GPIO lookup\n");
3963 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3964 } else if (ACPI_COMPANION(dev)) {
3965 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3966 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
3971 * Either we are not using DT or ACPI, or their lookup did not return
3972 * a result. In that case, use platform lookup as a fallback.
3974 if (!desc || desc == ERR_PTR(-ENOENT)) {
3975 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3976 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3980 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
3985 * If a connection label was passed use that, else attempt to use
3986 * the device name as label
3988 status = gpiod_request(desc, con_id ? con_id : devname);
3990 return ERR_PTR(status);
3992 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3994 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3996 return ERR_PTR(status);
4001 EXPORT_SYMBOL_GPL(gpiod_get_index);
4004 * gpiod_get_from_of_node() - obtain a GPIO from an OF node
4005 * @node: handle of the OF node
4006 * @propname: name of the DT property representing the GPIO
4007 * @index: index of the GPIO to obtain for the consumer
4008 * @dflags: GPIO initialization flags
4009 * @label: label to attach to the requested GPIO
4012 * On successful request the GPIO pin is configured in accordance with
4013 * provided @dflags. If the node does not have the requested GPIO
4014 * property, NULL is returned.
4016 * In case of error an ERR_PTR() is returned.
4018 struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
4019 const char *propname, int index,
4020 enum gpiod_flags dflags,
4023 struct gpio_desc *desc;
4024 unsigned long lflags = 0;
4025 enum of_gpio_flags flags;
4026 bool active_low = false;
4027 bool single_ended = false;
4028 bool open_drain = false;
4029 bool transitory = false;
4032 desc = of_get_named_gpiod_flags(node, propname,
4035 if (!desc || IS_ERR(desc)) {
4036 /* If it is not there, just return NULL */
4037 if (PTR_ERR(desc) == -ENOENT)
4042 active_low = flags & OF_GPIO_ACTIVE_LOW;
4043 single_ended = flags & OF_GPIO_SINGLE_ENDED;
4044 open_drain = flags & OF_GPIO_OPEN_DRAIN;
4045 transitory = flags & OF_GPIO_TRANSITORY;
4047 ret = gpiod_request(desc, label);
4049 return ERR_PTR(ret);
4052 lflags |= GPIO_ACTIVE_LOW;
4056 lflags |= GPIO_OPEN_DRAIN;
4058 lflags |= GPIO_OPEN_SOURCE;
4062 lflags |= GPIO_TRANSITORY;
4064 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4067 return ERR_PTR(ret);
4072 EXPORT_SYMBOL(gpiod_get_from_of_node);
4075 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
4076 * @fwnode: handle of the firmware node
4077 * @propname: name of the firmware property representing the GPIO
4078 * @index: index of the GPIO to obtain for the consumer
4079 * @dflags: GPIO initialization flags
4080 * @label: label to attach to the requested GPIO
4082 * This function can be used for drivers that get their configuration
4083 * from opaque firmware.
4085 * The function properly finds the corresponding GPIO using whatever is the
4086 * underlying firmware interface and then makes sure that the GPIO
4087 * descriptor is requested before it is returned to the caller.
4090 * On successful request the GPIO pin is configured in accordance with
4093 * In case of error an ERR_PTR() is returned.
4095 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
4096 const char *propname, int index,
4097 enum gpiod_flags dflags,
4100 struct gpio_desc *desc = ERR_PTR(-ENODEV);
4101 unsigned long lflags = 0;
4105 return ERR_PTR(-EINVAL);
4107 if (is_of_node(fwnode)) {
4108 desc = gpiod_get_from_of_node(to_of_node(fwnode),
4113 } else if (is_acpi_node(fwnode)) {
4114 struct acpi_gpio_info info;
4116 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4120 acpi_gpio_update_gpiod_flags(&dflags, &info);
4122 if (info.polarity == GPIO_ACTIVE_LOW)
4123 lflags |= GPIO_ACTIVE_LOW;
4126 /* Currently only ACPI takes this path */
4127 ret = gpiod_request(desc, label);
4129 return ERR_PTR(ret);
4131 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4134 return ERR_PTR(ret);
4139 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4142 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4144 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4145 * @con_id: function within the GPIO consumer
4146 * @index: index of the GPIO to obtain in the consumer
4147 * @flags: optional GPIO initialization flags
4149 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4150 * specified index was assigned to the requested function it will return NULL.
4151 * This is convenient for drivers that need to handle optional GPIOs.
4153 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4156 enum gpiod_flags flags)
4158 struct gpio_desc *desc;
4160 desc = gpiod_get_index(dev, con_id, index, flags);
4162 if (PTR_ERR(desc) == -ENOENT)
4168 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4171 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4172 * @desc: gpio whose value will be assigned
4173 * @name: gpio line name
4174 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
4176 * @dflags: gpiod_flags - optional GPIO initialization flags
4178 int gpiod_hog(struct gpio_desc *desc, const char *name,
4179 unsigned long lflags, enum gpiod_flags dflags)
4181 struct gpio_chip *chip;
4182 struct gpio_desc *local_desc;
4186 chip = gpiod_to_chip(desc);
4187 hwnum = gpio_chip_hwgpio(desc);
4189 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
4190 if (IS_ERR(local_desc)) {
4191 status = PTR_ERR(local_desc);
4192 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4193 name, chip->label, hwnum, status);
4197 status = gpiod_configure_flags(desc, name, lflags, dflags);
4199 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
4200 name, chip->label, hwnum, status);
4201 gpiochip_free_own_desc(desc);
4205 /* Mark GPIO as hogged so it can be identified and removed later */
4206 set_bit(FLAG_IS_HOGGED, &desc->flags);
4208 pr_info("GPIO line %d (%s) hogged as %s%s\n",
4209 desc_to_gpio(desc), name,
4210 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4211 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
4212 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
4218 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4219 * @chip: gpio chip to act on
4221 * This is only used by of_gpiochip_remove to free hogged gpios
4223 static void gpiochip_free_hogs(struct gpio_chip *chip)
4227 for (id = 0; id < chip->ngpio; id++) {
4228 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
4229 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
4234 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4235 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4236 * @con_id: function within the GPIO consumer
4237 * @flags: optional GPIO initialization flags
4239 * This function acquires all the GPIOs defined under a given function.
4241 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4242 * no GPIO has been assigned to the requested function, or another IS_ERR()
4243 * code if an error occurred while trying to acquire the GPIOs.
4245 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4247 enum gpiod_flags flags)
4249 struct gpio_desc *desc;
4250 struct gpio_descs *descs;
4253 count = gpiod_count(dev, con_id);
4255 return ERR_PTR(count);
4257 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4259 return ERR_PTR(-ENOMEM);
4261 for (descs->ndescs = 0; descs->ndescs < count; ) {
4262 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4264 gpiod_put_array(descs);
4265 return ERR_CAST(desc);
4267 descs->desc[descs->ndescs] = desc;
4272 EXPORT_SYMBOL_GPL(gpiod_get_array);
4275 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4277 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4278 * @con_id: function within the GPIO consumer
4279 * @flags: optional GPIO initialization flags
4281 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4282 * assigned to the requested function it will return NULL.
4284 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4286 enum gpiod_flags flags)
4288 struct gpio_descs *descs;
4290 descs = gpiod_get_array(dev, con_id, flags);
4291 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
4296 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4299 * gpiod_put - dispose of a GPIO descriptor
4300 * @desc: GPIO descriptor to dispose of
4302 * No descriptor can be used after gpiod_put() has been called on it.
4304 void gpiod_put(struct gpio_desc *desc)
4308 EXPORT_SYMBOL_GPL(gpiod_put);
4311 * gpiod_put_array - dispose of multiple GPIO descriptors
4312 * @descs: struct gpio_descs containing an array of descriptors
4314 void gpiod_put_array(struct gpio_descs *descs)
4318 for (i = 0; i < descs->ndescs; i++)
4319 gpiod_put(descs->desc[i]);
4323 EXPORT_SYMBOL_GPL(gpiod_put_array);
4325 static int __init gpiolib_dev_init(void)
4329 /* Register GPIO sysfs bus */
4330 ret = bus_register(&gpio_bus_type);
4332 pr_err("gpiolib: could not register GPIO bus type\n");
4336 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
4338 pr_err("gpiolib: failed to allocate char dev region\n");
4339 bus_unregister(&gpio_bus_type);
4341 gpiolib_initialized = true;
4342 gpiochip_setup_devs();
4346 core_initcall(gpiolib_dev_init);
4348 #ifdef CONFIG_DEBUG_FS
4350 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4353 struct gpio_chip *chip = gdev->chip;
4354 unsigned gpio = gdev->base;
4355 struct gpio_desc *gdesc = &gdev->descs[0];
4359 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4360 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4362 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4368 gpiod_get_direction(gdesc);
4369 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4370 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4371 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
4372 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4373 is_out ? "out" : "in ",
4374 chip->get ? (chip->get(chip, i) ? "hi" : "lo") : "? ",
4375 is_irq ? "IRQ" : " ");
4376 seq_printf(s, "\n");
4380 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4382 unsigned long flags;
4383 struct gpio_device *gdev = NULL;
4384 loff_t index = *pos;
4388 spin_lock_irqsave(&gpio_lock, flags);
4389 list_for_each_entry(gdev, &gpio_devices, list)
4391 spin_unlock_irqrestore(&gpio_lock, flags);
4394 spin_unlock_irqrestore(&gpio_lock, flags);
4399 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4401 unsigned long flags;
4402 struct gpio_device *gdev = v;
4405 spin_lock_irqsave(&gpio_lock, flags);
4406 if (list_is_last(&gdev->list, &gpio_devices))
4409 ret = list_entry(gdev->list.next, struct gpio_device, list);
4410 spin_unlock_irqrestore(&gpio_lock, flags);
4418 static void gpiolib_seq_stop(struct seq_file *s, void *v)
4422 static int gpiolib_seq_show(struct seq_file *s, void *v)
4424 struct gpio_device *gdev = v;
4425 struct gpio_chip *chip = gdev->chip;
4426 struct device *parent;
4429 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4430 dev_name(&gdev->dev));
4434 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4435 dev_name(&gdev->dev),
4436 gdev->base, gdev->base + gdev->ngpio - 1);
4437 parent = chip->parent;
4439 seq_printf(s, ", parent: %s/%s",
4440 parent->bus ? parent->bus->name : "no-bus",
4443 seq_printf(s, ", %s", chip->label);
4444 if (chip->can_sleep)
4445 seq_printf(s, ", can sleep");
4446 seq_printf(s, ":\n");
4449 chip->dbg_show(s, chip);
4451 gpiolib_dbg_show(s, gdev);
4456 static const struct seq_operations gpiolib_seq_ops = {
4457 .start = gpiolib_seq_start,
4458 .next = gpiolib_seq_next,
4459 .stop = gpiolib_seq_stop,
4460 .show = gpiolib_seq_show,
4463 static int gpiolib_open(struct inode *inode, struct file *file)
4465 return seq_open(file, &gpiolib_seq_ops);
4468 static const struct file_operations gpiolib_operations = {
4469 .owner = THIS_MODULE,
4470 .open = gpiolib_open,
4472 .llseek = seq_lseek,
4473 .release = seq_release,
4476 static int __init gpiolib_debugfs_init(void)
4478 /* /sys/kernel/debug/gpio */
4479 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
4480 NULL, NULL, &gpiolib_operations);
4483 subsys_initcall(gpiolib_debugfs_init);
4485 #endif /* DEBUG_FS */