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);
220 if (!chip->get_direction)
223 status = chip->get_direction(chip, offset);
225 /* GPIOF_DIR_IN, or other positive */
227 clear_bit(FLAG_IS_OUT, &desc->flags);
231 set_bit(FLAG_IS_OUT, &desc->flags);
235 EXPORT_SYMBOL_GPL(gpiod_get_direction);
238 * Add a new chip to the global chips list, keeping the list of chips sorted
239 * by range(means [base, base + ngpio - 1]) order.
241 * Return -EBUSY if the new chip overlaps with some other chip's integer
244 static int gpiodev_add_to_list(struct gpio_device *gdev)
246 struct gpio_device *prev, *next;
248 if (list_empty(&gpio_devices)) {
249 /* initial entry in list */
250 list_add_tail(&gdev->list, &gpio_devices);
254 next = list_entry(gpio_devices.next, struct gpio_device, list);
255 if (gdev->base + gdev->ngpio <= next->base) {
256 /* add before first entry */
257 list_add(&gdev->list, &gpio_devices);
261 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
262 if (prev->base + prev->ngpio <= gdev->base) {
263 /* add behind last entry */
264 list_add_tail(&gdev->list, &gpio_devices);
268 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
269 /* at the end of the list */
270 if (&next->list == &gpio_devices)
273 /* add between prev and next */
274 if (prev->base + prev->ngpio <= gdev->base
275 && gdev->base + gdev->ngpio <= next->base) {
276 list_add(&gdev->list, &prev->list);
281 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
286 * Convert a GPIO name to its descriptor
288 static struct gpio_desc *gpio_name_to_desc(const char * const name)
290 struct gpio_device *gdev;
293 spin_lock_irqsave(&gpio_lock, flags);
295 list_for_each_entry(gdev, &gpio_devices, list) {
298 for (i = 0; i != gdev->ngpio; ++i) {
299 struct gpio_desc *desc = &gdev->descs[i];
301 if (!desc->name || !name)
304 if (!strcmp(desc->name, name)) {
305 spin_unlock_irqrestore(&gpio_lock, flags);
311 spin_unlock_irqrestore(&gpio_lock, flags);
317 * Takes the names from gc->names and checks if they are all unique. If they
318 * are, they are assigned to their gpio descriptors.
320 * Warning if one of the names is already used for a different GPIO.
322 static int gpiochip_set_desc_names(struct gpio_chip *gc)
324 struct gpio_device *gdev = gc->gpiodev;
330 /* First check all names if they are unique */
331 for (i = 0; i != gc->ngpio; ++i) {
332 struct gpio_desc *gpio;
334 gpio = gpio_name_to_desc(gc->names[i]);
337 "Detected name collision for GPIO name '%s'\n",
341 /* Then add all names to the GPIO descriptors */
342 for (i = 0; i != gc->ngpio; ++i)
343 gdev->descs[i].name = gc->names[i];
348 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *chip)
352 p = kmalloc_array(BITS_TO_LONGS(chip->ngpio), sizeof(*p), GFP_KERNEL);
356 /* Assume by default all GPIOs are valid */
357 bitmap_fill(p, chip->ngpio);
362 static int gpiochip_init_valid_mask(struct gpio_chip *gpiochip)
364 #ifdef CONFIG_OF_GPIO
366 struct device_node *np = gpiochip->of_node;
368 size = of_property_count_u32_elems(np, "gpio-reserved-ranges");
369 if (size > 0 && size % 2 == 0)
370 gpiochip->need_valid_mask = true;
373 if (!gpiochip->need_valid_mask)
376 gpiochip->valid_mask = gpiochip_allocate_mask(gpiochip);
377 if (!gpiochip->valid_mask)
383 static void gpiochip_free_valid_mask(struct gpio_chip *gpiochip)
385 kfree(gpiochip->valid_mask);
386 gpiochip->valid_mask = NULL;
389 bool gpiochip_line_is_valid(const struct gpio_chip *gpiochip,
392 /* No mask means all valid */
393 if (likely(!gpiochip->valid_mask))
395 return test_bit(offset, gpiochip->valid_mask);
397 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
400 * GPIO line handle management
404 * struct linehandle_state - contains the state of a userspace handle
405 * @gdev: the GPIO device the handle pertains to
406 * @label: consumer label used to tag descriptors
407 * @descs: the GPIO descriptors held by this handle
408 * @numdescs: the number of descriptors held in the descs array
410 struct linehandle_state {
411 struct gpio_device *gdev;
413 struct gpio_desc *descs[GPIOHANDLES_MAX];
417 #define GPIOHANDLE_REQUEST_VALID_FLAGS \
418 (GPIOHANDLE_REQUEST_INPUT | \
419 GPIOHANDLE_REQUEST_OUTPUT | \
420 GPIOHANDLE_REQUEST_ACTIVE_LOW | \
421 GPIOHANDLE_REQUEST_OPEN_DRAIN | \
422 GPIOHANDLE_REQUEST_OPEN_SOURCE)
424 static long linehandle_ioctl(struct file *filep, unsigned int cmd,
427 struct linehandle_state *lh = filep->private_data;
428 void __user *ip = (void __user *)arg;
429 struct gpiohandle_data ghd;
430 int vals[GPIOHANDLES_MAX];
433 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
434 /* TODO: check if descriptors are really input */
435 int ret = gpiod_get_array_value_complex(false,
443 memset(&ghd, 0, sizeof(ghd));
444 for (i = 0; i < lh->numdescs; i++)
445 ghd.values[i] = vals[i];
447 if (copy_to_user(ip, &ghd, sizeof(ghd)))
451 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
453 * All line descriptors were created at once with the same
454 * flags so just check if the first one is really output.
456 if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags))
459 if (copy_from_user(&ghd, ip, sizeof(ghd)))
462 /* Clamp all values to [0,1] */
463 for (i = 0; i < lh->numdescs; i++)
464 vals[i] = !!ghd.values[i];
466 /* Reuse the array setting function */
467 return gpiod_set_array_value_complex(false,
477 static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
480 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
484 static int linehandle_release(struct inode *inode, struct file *filep)
486 struct linehandle_state *lh = filep->private_data;
487 struct gpio_device *gdev = lh->gdev;
490 for (i = 0; i < lh->numdescs; i++)
491 gpiod_free(lh->descs[i]);
494 put_device(&gdev->dev);
498 static const struct file_operations linehandle_fileops = {
499 .release = linehandle_release,
500 .owner = THIS_MODULE,
501 .llseek = noop_llseek,
502 .unlocked_ioctl = linehandle_ioctl,
504 .compat_ioctl = linehandle_ioctl_compat,
508 static int linehandle_create(struct gpio_device *gdev, void __user *ip)
510 struct gpiohandle_request handlereq;
511 struct linehandle_state *lh;
513 int fd, i, count = 0, ret;
516 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
518 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
521 lflags = handlereq.flags;
523 /* Return an error if an unknown flag is set */
524 if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
528 * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
529 * the hardware actually supports enabling both at the same time the
530 * electrical result would be disastrous.
532 if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
533 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
536 /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
537 if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) &&
538 ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
539 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
542 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
546 get_device(&gdev->dev);
548 /* Make sure this is terminated */
549 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
550 if (strlen(handlereq.consumer_label)) {
551 lh->label = kstrdup(handlereq.consumer_label,
559 /* Request each GPIO */
560 for (i = 0; i < handlereq.lines; i++) {
561 u32 offset = handlereq.lineoffsets[i];
562 struct gpio_desc *desc;
564 if (offset >= gdev->ngpio) {
569 desc = &gdev->descs[offset];
570 ret = gpiod_request(desc, lh->label);
576 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
577 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
578 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
579 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
580 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
581 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
583 ret = gpiod_set_transitory(desc, false);
588 * Lines have to be requested explicitly for input
589 * or output, else the line will be treated "as is".
591 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
592 int val = !!handlereq.default_values[i];
594 ret = gpiod_direction_output(desc, val);
597 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
598 ret = gpiod_direction_input(desc);
602 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
605 /* Let i point at the last handle */
607 lh->numdescs = handlereq.lines;
609 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
615 file = anon_inode_getfile("gpio-linehandle",
618 O_RDONLY | O_CLOEXEC);
621 goto out_put_unused_fd;
625 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
627 * fput() will trigger the release() callback, so do not go onto
628 * the regular error cleanup path here.
635 fd_install(fd, file);
637 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
645 for (i = 0; i < count; i++)
646 gpiod_free(lh->descs[i]);
650 put_device(&gdev->dev);
655 * GPIO line event management
659 * struct lineevent_state - contains the state of a userspace event
660 * @gdev: the GPIO device the event pertains to
661 * @label: consumer label used to tag descriptors
662 * @desc: the GPIO descriptor held by this event
663 * @eflags: the event flags this line was requested with
664 * @irq: the interrupt that trigger in response to events on this GPIO
665 * @wait: wait queue that handles blocking reads of events
666 * @events: KFIFO for the GPIO events
667 * @read_lock: mutex lock to protect reads from colliding with adding
668 * new events to the FIFO
669 * @timestamp: cache for the timestamp storing it between hardirq
670 * and IRQ thread, used to bring the timestamp close to the actual
673 struct lineevent_state {
674 struct gpio_device *gdev;
676 struct gpio_desc *desc;
679 wait_queue_head_t wait;
680 DECLARE_KFIFO(events, struct gpioevent_data, 16);
681 struct mutex read_lock;
685 #define GPIOEVENT_REQUEST_VALID_FLAGS \
686 (GPIOEVENT_REQUEST_RISING_EDGE | \
687 GPIOEVENT_REQUEST_FALLING_EDGE)
689 static __poll_t lineevent_poll(struct file *filep,
690 struct poll_table_struct *wait)
692 struct lineevent_state *le = filep->private_data;
695 poll_wait(filep, &le->wait, wait);
697 if (!kfifo_is_empty(&le->events))
698 events = EPOLLIN | EPOLLRDNORM;
704 static ssize_t lineevent_read(struct file *filep,
709 struct lineevent_state *le = filep->private_data;
713 if (count < sizeof(struct gpioevent_data))
717 if (kfifo_is_empty(&le->events)) {
718 if (filep->f_flags & O_NONBLOCK)
721 ret = wait_event_interruptible(le->wait,
722 !kfifo_is_empty(&le->events));
727 if (mutex_lock_interruptible(&le->read_lock))
729 ret = kfifo_to_user(&le->events, buf, count, &copied);
730 mutex_unlock(&le->read_lock);
736 * If we couldn't read anything from the fifo (a different
737 * thread might have been faster) we either return -EAGAIN if
738 * the file descriptor is non-blocking, otherwise we go back to
739 * sleep and wait for more data to arrive.
741 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
744 } while (copied == 0);
749 static int lineevent_release(struct inode *inode, struct file *filep)
751 struct lineevent_state *le = filep->private_data;
752 struct gpio_device *gdev = le->gdev;
754 free_irq(le->irq, le);
755 gpiod_free(le->desc);
758 put_device(&gdev->dev);
762 static long lineevent_ioctl(struct file *filep, unsigned int cmd,
765 struct lineevent_state *le = filep->private_data;
766 void __user *ip = (void __user *)arg;
767 struct gpiohandle_data ghd;
770 * We can get the value for an event line but not set it,
771 * because it is input by definition.
773 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
776 memset(&ghd, 0, sizeof(ghd));
778 val = gpiod_get_value_cansleep(le->desc);
783 if (copy_to_user(ip, &ghd, sizeof(ghd)))
792 static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
795 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
799 static const struct file_operations lineevent_fileops = {
800 .release = lineevent_release,
801 .read = lineevent_read,
802 .poll = lineevent_poll,
803 .owner = THIS_MODULE,
804 .llseek = noop_llseek,
805 .unlocked_ioctl = lineevent_ioctl,
807 .compat_ioctl = lineevent_ioctl_compat,
811 static irqreturn_t lineevent_irq_thread(int irq, void *p)
813 struct lineevent_state *le = p;
814 struct gpioevent_data ge;
817 /* Do not leak kernel stack to userspace */
818 memset(&ge, 0, sizeof(ge));
820 ge.timestamp = le->timestamp;
821 level = gpiod_get_value_cansleep(le->desc);
823 if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
824 && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
826 /* Emit low-to-high event */
827 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
829 /* Emit high-to-low event */
830 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
831 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE && level) {
832 /* Emit low-to-high event */
833 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
834 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE && !level) {
835 /* Emit high-to-low event */
836 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
841 ret = kfifo_put(&le->events, ge);
843 wake_up_poll(&le->wait, EPOLLIN);
848 static irqreturn_t lineevent_irq_handler(int irq, void *p)
850 struct lineevent_state *le = p;
853 * Just store the timestamp in hardirq context so we get it as
854 * close in time as possible to the actual event.
856 le->timestamp = ktime_get_real_ns();
858 return IRQ_WAKE_THREAD;
861 static int lineevent_create(struct gpio_device *gdev, void __user *ip)
863 struct gpioevent_request eventreq;
864 struct lineevent_state *le;
865 struct gpio_desc *desc;
874 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
877 le = kzalloc(sizeof(*le), GFP_KERNEL);
881 get_device(&gdev->dev);
883 /* Make sure this is terminated */
884 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
885 if (strlen(eventreq.consumer_label)) {
886 le->label = kstrdup(eventreq.consumer_label,
894 offset = eventreq.lineoffset;
895 lflags = eventreq.handleflags;
896 eflags = eventreq.eventflags;
898 if (offset >= gdev->ngpio) {
903 /* Return an error if a unknown flag is set */
904 if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
905 (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
910 /* This is just wrong: we don't look for events on output lines */
911 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
916 desc = &gdev->descs[offset];
917 ret = gpiod_request(desc, le->label);
923 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
924 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
925 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
926 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
927 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
928 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
930 ret = gpiod_direction_input(desc);
934 le->irq = gpiod_to_irq(desc);
940 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
941 irqflags |= IRQF_TRIGGER_RISING;
942 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
943 irqflags |= IRQF_TRIGGER_FALLING;
944 irqflags |= IRQF_ONESHOT;
945 irqflags |= IRQF_SHARED;
947 INIT_KFIFO(le->events);
948 init_waitqueue_head(&le->wait);
949 mutex_init(&le->read_lock);
951 /* Request a thread to read the events */
952 ret = request_threaded_irq(le->irq,
953 lineevent_irq_handler,
954 lineevent_irq_thread,
961 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
967 file = anon_inode_getfile("gpio-event",
970 O_RDONLY | O_CLOEXEC);
973 goto out_put_unused_fd;
977 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
979 * fput() will trigger the release() callback, so do not go onto
980 * the regular error cleanup path here.
987 fd_install(fd, file);
994 free_irq(le->irq, le);
996 gpiod_free(le->desc);
1001 put_device(&gdev->dev);
1006 * gpio_ioctl() - ioctl handler for the GPIO chardev
1008 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1010 struct gpio_device *gdev = filp->private_data;
1011 struct gpio_chip *chip = gdev->chip;
1012 void __user *ip = (void __user *)arg;
1014 /* We fail any subsequent ioctl():s when the chip is gone */
1018 /* Fill in the struct and pass to userspace */
1019 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
1020 struct gpiochip_info chipinfo;
1022 memset(&chipinfo, 0, sizeof(chipinfo));
1024 strncpy(chipinfo.name, dev_name(&gdev->dev),
1025 sizeof(chipinfo.name));
1026 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
1027 strncpy(chipinfo.label, gdev->label,
1028 sizeof(chipinfo.label));
1029 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
1030 chipinfo.lines = gdev->ngpio;
1031 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
1034 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
1035 struct gpioline_info lineinfo;
1036 struct gpio_desc *desc;
1038 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
1040 if (lineinfo.line_offset >= gdev->ngpio)
1043 desc = &gdev->descs[lineinfo.line_offset];
1045 strncpy(lineinfo.name, desc->name,
1046 sizeof(lineinfo.name));
1047 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
1049 lineinfo.name[0] = '\0';
1052 strncpy(lineinfo.consumer, desc->label,
1053 sizeof(lineinfo.consumer));
1054 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
1056 lineinfo.consumer[0] = '\0';
1060 * Userspace only need to know that the kernel is using
1061 * this GPIO so it can't use it.
1064 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
1065 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
1066 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
1067 test_bit(FLAG_EXPORT, &desc->flags) ||
1068 test_bit(FLAG_SYSFS, &desc->flags))
1069 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
1070 if (test_bit(FLAG_IS_OUT, &desc->flags))
1071 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
1072 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1073 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
1074 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1075 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
1076 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1077 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
1079 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
1082 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
1083 return linehandle_create(gdev, ip);
1084 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
1085 return lineevent_create(gdev, ip);
1090 #ifdef CONFIG_COMPAT
1091 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
1094 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
1099 * gpio_chrdev_open() - open the chardev for ioctl operations
1100 * @inode: inode for this chardev
1101 * @filp: file struct for storing private data
1102 * Returns 0 on success
1104 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
1106 struct gpio_device *gdev = container_of(inode->i_cdev,
1107 struct gpio_device, chrdev);
1109 /* Fail on open if the backing gpiochip is gone */
1112 get_device(&gdev->dev);
1113 filp->private_data = gdev;
1115 return nonseekable_open(inode, filp);
1119 * gpio_chrdev_release() - close chardev after ioctl operations
1120 * @inode: inode for this chardev
1121 * @filp: file struct for storing private data
1122 * Returns 0 on success
1124 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1126 struct gpio_device *gdev = container_of(inode->i_cdev,
1127 struct gpio_device, chrdev);
1129 put_device(&gdev->dev);
1134 static const struct file_operations gpio_fileops = {
1135 .release = gpio_chrdev_release,
1136 .open = gpio_chrdev_open,
1137 .owner = THIS_MODULE,
1138 .llseek = no_llseek,
1139 .unlocked_ioctl = gpio_ioctl,
1140 #ifdef CONFIG_COMPAT
1141 .compat_ioctl = gpio_ioctl_compat,
1145 static void gpiodevice_release(struct device *dev)
1147 struct gpio_device *gdev = dev_get_drvdata(dev);
1149 list_del(&gdev->list);
1150 ida_simple_remove(&gpio_ida, gdev->id);
1151 kfree_const(gdev->label);
1156 static int gpiochip_setup_dev(struct gpio_device *gdev)
1160 cdev_init(&gdev->chrdev, &gpio_fileops);
1161 gdev->chrdev.owner = THIS_MODULE;
1162 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1164 status = cdev_device_add(&gdev->chrdev, &gdev->dev);
1168 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1169 MAJOR(gpio_devt), gdev->id);
1171 status = gpiochip_sysfs_register(gdev);
1173 goto err_remove_device;
1175 /* From this point, the .release() function cleans up gpio_device */
1176 gdev->dev.release = gpiodevice_release;
1177 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1178 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1179 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1184 cdev_device_del(&gdev->chrdev, &gdev->dev);
1188 static void gpiochip_machine_hog(struct gpio_chip *chip, struct gpiod_hog *hog)
1190 struct gpio_desc *desc;
1193 desc = gpiochip_get_desc(chip, hog->chip_hwnum);
1195 pr_err("%s: unable to get GPIO desc: %ld\n",
1196 __func__, PTR_ERR(desc));
1200 if (test_bit(FLAG_IS_HOGGED, &desc->flags))
1203 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
1205 pr_err("%s: unable to hog GPIO line (%s:%u): %d\n",
1206 __func__, chip->label, hog->chip_hwnum, rv);
1209 static void machine_gpiochip_add(struct gpio_chip *chip)
1211 struct gpiod_hog *hog;
1213 mutex_lock(&gpio_machine_hogs_mutex);
1215 list_for_each_entry(hog, &gpio_machine_hogs, list) {
1216 if (!strcmp(chip->label, hog->chip_label))
1217 gpiochip_machine_hog(chip, hog);
1220 mutex_unlock(&gpio_machine_hogs_mutex);
1223 static void gpiochip_setup_devs(void)
1225 struct gpio_device *gdev;
1228 list_for_each_entry(gdev, &gpio_devices, list) {
1229 err = gpiochip_setup_dev(gdev);
1231 pr_err("%s: Failed to initialize gpio device (%d)\n",
1232 dev_name(&gdev->dev), err);
1236 int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
1237 struct lock_class_key *lock_key,
1238 struct lock_class_key *request_key)
1240 unsigned long flags;
1243 int base = chip->base;
1244 struct gpio_device *gdev;
1247 * First: allocate and populate the internal stat container, and
1248 * set up the struct device.
1250 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1253 gdev->dev.bus = &gpio_bus_type;
1255 chip->gpiodev = gdev;
1257 gdev->dev.parent = chip->parent;
1258 gdev->dev.of_node = chip->parent->of_node;
1261 #ifdef CONFIG_OF_GPIO
1262 /* If the gpiochip has an assigned OF node this takes precedence */
1264 gdev->dev.of_node = chip->of_node;
1267 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1272 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1273 device_initialize(&gdev->dev);
1274 dev_set_drvdata(&gdev->dev, gdev);
1275 if (chip->parent && chip->parent->driver)
1276 gdev->owner = chip->parent->driver->owner;
1277 else if (chip->owner)
1278 /* TODO: remove chip->owner */
1279 gdev->owner = chip->owner;
1281 gdev->owner = THIS_MODULE;
1283 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1289 if (chip->ngpio == 0) {
1290 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1292 goto err_free_descs;
1295 if (chip->ngpio > FASTPATH_NGPIO)
1296 chip_warn(chip, "line cnt %u is greater than fast path cnt %u\n",
1297 chip->ngpio, FASTPATH_NGPIO);
1299 gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
1302 goto err_free_descs;
1305 gdev->ngpio = chip->ngpio;
1308 spin_lock_irqsave(&gpio_lock, flags);
1311 * TODO: this allocates a Linux GPIO number base in the global
1312 * GPIO numberspace for this chip. In the long run we want to
1313 * get *rid* of this numberspace and use only descriptors, but
1314 * it may be a pipe dream. It will not happen before we get rid
1315 * of the sysfs interface anyways.
1318 base = gpiochip_find_base(chip->ngpio);
1321 spin_unlock_irqrestore(&gpio_lock, flags);
1322 goto err_free_label;
1325 * TODO: it should not be necessary to reflect the assigned
1326 * base outside of the GPIO subsystem. Go over drivers and
1327 * see if anyone makes use of this, else drop this and assign
1334 status = gpiodev_add_to_list(gdev);
1336 spin_unlock_irqrestore(&gpio_lock, flags);
1337 goto err_free_label;
1340 spin_unlock_irqrestore(&gpio_lock, flags);
1342 for (i = 0; i < chip->ngpio; i++) {
1343 struct gpio_desc *desc = &gdev->descs[i];
1347 /* REVISIT: most hardware initializes GPIOs as inputs (often
1348 * with pullups enabled) so power usage is minimized. Linux
1349 * code should set the gpio direction first thing; but until
1350 * it does, and in case chip->get_direction is not set, we may
1351 * expose the wrong direction in sysfs.
1353 desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
1356 #ifdef CONFIG_PINCTRL
1357 INIT_LIST_HEAD(&gdev->pin_ranges);
1360 status = gpiochip_set_desc_names(chip);
1362 goto err_remove_from_list;
1364 status = gpiochip_irqchip_init_valid_mask(chip);
1366 goto err_remove_from_list;
1368 status = gpiochip_init_valid_mask(chip);
1370 goto err_remove_irqchip_mask;
1372 status = gpiochip_add_irqchip(chip, lock_key, request_key);
1374 goto err_remove_chip;
1376 status = of_gpiochip_add(chip);
1378 goto err_remove_chip;
1380 acpi_gpiochip_add(chip);
1382 machine_gpiochip_add(chip);
1385 * By first adding the chardev, and then adding the device,
1386 * we get a device node entry in sysfs under
1387 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1388 * coldplug of device nodes and other udev business.
1389 * We can do this only if gpiolib has been initialized.
1390 * Otherwise, defer until later.
1392 if (gpiolib_initialized) {
1393 status = gpiochip_setup_dev(gdev);
1395 goto err_remove_chip;
1400 acpi_gpiochip_remove(chip);
1401 gpiochip_free_hogs(chip);
1402 of_gpiochip_remove(chip);
1403 gpiochip_free_valid_mask(chip);
1404 err_remove_irqchip_mask:
1405 gpiochip_irqchip_free_valid_mask(chip);
1406 err_remove_from_list:
1407 spin_lock_irqsave(&gpio_lock, flags);
1408 list_del(&gdev->list);
1409 spin_unlock_irqrestore(&gpio_lock, flags);
1411 kfree_const(gdev->label);
1415 ida_simple_remove(&gpio_ida, gdev->id);
1416 /* failures here can mean systems won't boot... */
1417 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
1418 gdev->base, gdev->base + gdev->ngpio - 1,
1419 chip->label ? : "generic");
1423 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1426 * gpiochip_get_data() - get per-subdriver data for the chip
1430 * The per-subdriver data for the chip.
1432 void *gpiochip_get_data(struct gpio_chip *chip)
1434 return chip->gpiodev->data;
1436 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1439 * gpiochip_remove() - unregister a gpio_chip
1440 * @chip: the chip to unregister
1442 * A gpio_chip with any GPIOs still requested may not be removed.
1444 void gpiochip_remove(struct gpio_chip *chip)
1446 struct gpio_device *gdev = chip->gpiodev;
1447 struct gpio_desc *desc;
1448 unsigned long flags;
1450 bool requested = false;
1452 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1453 gpiochip_sysfs_unregister(gdev);
1454 gpiochip_free_hogs(chip);
1455 /* Numb the device, cancelling all outstanding operations */
1457 gpiochip_irqchip_remove(chip);
1458 acpi_gpiochip_remove(chip);
1459 gpiochip_remove_pin_ranges(chip);
1460 of_gpiochip_remove(chip);
1461 gpiochip_free_valid_mask(chip);
1463 * We accept no more calls into the driver from this point, so
1464 * NULL the driver data pointer
1468 spin_lock_irqsave(&gpio_lock, flags);
1469 for (i = 0; i < gdev->ngpio; i++) {
1470 desc = &gdev->descs[i];
1471 if (test_bit(FLAG_REQUESTED, &desc->flags))
1474 spin_unlock_irqrestore(&gpio_lock, flags);
1477 dev_crit(&gdev->dev,
1478 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1481 * The gpiochip side puts its use of the device to rest here:
1482 * if there are no userspace clients, the chardev and device will
1483 * be removed, else it will be dangling until the last user is
1486 cdev_device_del(&gdev->chrdev, &gdev->dev);
1487 put_device(&gdev->dev);
1489 EXPORT_SYMBOL_GPL(gpiochip_remove);
1491 static void devm_gpio_chip_release(struct device *dev, void *res)
1493 struct gpio_chip *chip = *(struct gpio_chip **)res;
1495 gpiochip_remove(chip);
1498 static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
1501 struct gpio_chip **r = res;
1512 * devm_gpiochip_add_data() - Resource manager gpiochip_add_data()
1513 * @dev: the device pointer on which irq_chip belongs to.
1514 * @chip: the chip to register, with chip->base initialized
1515 * @data: driver-private data associated with this chip
1517 * Context: potentially before irqs will work
1519 * The gpio chip automatically be released when the device is unbound.
1522 * A negative errno if the chip can't be registered, such as because the
1523 * chip->base is invalid or already associated with a different chip.
1524 * Otherwise it returns zero as a success code.
1526 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1529 struct gpio_chip **ptr;
1532 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1537 ret = gpiochip_add_data(chip, data);
1544 devres_add(dev, ptr);
1548 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1551 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1552 * @dev: device for which which resource was allocated
1553 * @chip: the chip to remove
1555 * A gpio_chip with any GPIOs still requested may not be removed.
1557 void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
1561 ret = devres_release(dev, devm_gpio_chip_release,
1562 devm_gpio_chip_match, chip);
1565 EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
1568 * gpiochip_find() - iterator for locating a specific gpio_chip
1569 * @data: data to pass to match function
1570 * @match: Callback function to check gpio_chip
1572 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1573 * determined by a user supplied @match callback. The callback should return
1574 * 0 if the device doesn't match and non-zero if it does. If the callback is
1575 * non-zero, this function will return to the caller and not iterate over any
1578 struct gpio_chip *gpiochip_find(void *data,
1579 int (*match)(struct gpio_chip *chip,
1582 struct gpio_device *gdev;
1583 struct gpio_chip *chip = NULL;
1584 unsigned long flags;
1586 spin_lock_irqsave(&gpio_lock, flags);
1587 list_for_each_entry(gdev, &gpio_devices, list)
1588 if (gdev->chip && match(gdev->chip, data)) {
1593 spin_unlock_irqrestore(&gpio_lock, flags);
1597 EXPORT_SYMBOL_GPL(gpiochip_find);
1599 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1601 const char *name = data;
1603 return !strcmp(chip->label, name);
1606 static struct gpio_chip *find_chip_by_name(const char *name)
1608 return gpiochip_find((void *)name, gpiochip_match_name);
1611 #ifdef CONFIG_GPIOLIB_IRQCHIP
1614 * The following is irqchip helper code for gpiochips.
1617 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1619 if (!gpiochip->irq.need_valid_mask)
1622 gpiochip->irq.valid_mask = gpiochip_allocate_mask(gpiochip);
1623 if (!gpiochip->irq.valid_mask)
1629 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1631 kfree(gpiochip->irq.valid_mask);
1632 gpiochip->irq.valid_mask = NULL;
1635 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1636 unsigned int offset)
1638 if (!gpiochip_line_is_valid(gpiochip, offset))
1640 /* No mask means all valid */
1641 if (likely(!gpiochip->irq.valid_mask))
1643 return test_bit(offset, gpiochip->irq.valid_mask);
1645 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1648 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1649 * @gpiochip: the gpiochip to set the irqchip chain to
1650 * @irqchip: the irqchip to chain to the gpiochip
1651 * @parent_irq: the irq number corresponding to the parent IRQ for this
1653 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1654 * coming out of the gpiochip. If the interrupt is nested rather than
1655 * cascaded, pass NULL in this handler argument
1657 static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
1658 struct irq_chip *irqchip,
1659 unsigned int parent_irq,
1660 irq_flow_handler_t parent_handler)
1662 unsigned int offset;
1664 if (!gpiochip->irq.domain) {
1665 chip_err(gpiochip, "called %s before setting up irqchip\n",
1670 if (parent_handler) {
1671 if (gpiochip->can_sleep) {
1673 "you cannot have chained interrupts on a chip that may sleep\n");
1677 * The parent irqchip is already using the chip_data for this
1678 * irqchip, so our callbacks simply use the handler_data.
1680 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1683 gpiochip->irq.parents = &parent_irq;
1684 gpiochip->irq.num_parents = 1;
1687 /* Set the parent IRQ for all affected IRQs */
1688 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1689 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1691 irq_set_parent(irq_find_mapping(gpiochip->irq.domain, offset),
1697 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1698 * @gpiochip: the gpiochip to set the irqchip chain to
1699 * @irqchip: the irqchip to chain to the gpiochip
1700 * @parent_irq: the irq number corresponding to the parent IRQ for this
1702 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1703 * coming out of the gpiochip. If the interrupt is nested rather than
1704 * cascaded, pass NULL in this handler argument
1706 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1707 struct irq_chip *irqchip,
1708 unsigned int parent_irq,
1709 irq_flow_handler_t parent_handler)
1711 if (gpiochip->irq.threaded) {
1712 chip_err(gpiochip, "tried to chain a threaded gpiochip\n");
1716 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1719 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1722 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1723 * @gpiochip: the gpiochip to set the irqchip nested handler to
1724 * @irqchip: the irqchip to nest to the gpiochip
1725 * @parent_irq: the irq number corresponding to the parent IRQ for this
1728 void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1729 struct irq_chip *irqchip,
1730 unsigned int parent_irq)
1732 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1735 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1738 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1739 * @d: the irqdomain used by this irqchip
1740 * @irq: the global irq number used by this GPIO irqchip irq
1741 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1743 * This function will set up the mapping for a certain IRQ line on a
1744 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1745 * stored inside the gpiochip.
1747 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1748 irq_hw_number_t hwirq)
1750 struct gpio_chip *chip = d->host_data;
1753 if (!gpiochip_irqchip_irq_valid(chip, hwirq))
1756 irq_set_chip_data(irq, chip);
1758 * This lock class tells lockdep that GPIO irqs are in a different
1759 * category than their parents, so it won't report false recursion.
1761 irq_set_lockdep_class(irq, chip->irq.lock_key, chip->irq.request_key);
1762 irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
1763 /* Chips that use nested thread handlers have them marked */
1764 if (chip->irq.threaded)
1765 irq_set_nested_thread(irq, 1);
1766 irq_set_noprobe(irq);
1768 if (chip->irq.num_parents == 1)
1769 err = irq_set_parent(irq, chip->irq.parents[0]);
1770 else if (chip->irq.map)
1771 err = irq_set_parent(irq, chip->irq.map[hwirq]);
1777 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1778 * is passed as default type.
1780 if (chip->irq.default_type != IRQ_TYPE_NONE)
1781 irq_set_irq_type(irq, chip->irq.default_type);
1785 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1787 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1789 struct gpio_chip *chip = d->host_data;
1791 if (chip->irq.threaded)
1792 irq_set_nested_thread(irq, 0);
1793 irq_set_chip_and_handler(irq, NULL, NULL);
1794 irq_set_chip_data(irq, NULL);
1796 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1798 static const struct irq_domain_ops gpiochip_domain_ops = {
1799 .map = gpiochip_irq_map,
1800 .unmap = gpiochip_irq_unmap,
1801 /* Virtually all GPIO irqchips are twocell:ed */
1802 .xlate = irq_domain_xlate_twocell,
1805 static int gpiochip_irq_reqres(struct irq_data *d)
1807 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1809 if (!try_module_get(chip->gpiodev->owner))
1812 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
1814 "unable to lock HW IRQ %lu for IRQ\n",
1816 module_put(chip->gpiodev->owner);
1822 static void gpiochip_irq_relres(struct irq_data *d)
1824 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1826 gpiochip_unlock_as_irq(chip, d->hwirq);
1827 module_put(chip->gpiodev->owner);
1830 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1832 if (!gpiochip_irqchip_irq_valid(chip, offset))
1835 return irq_create_mapping(chip->irq.domain, offset);
1839 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1840 * @gpiochip: the GPIO chip to add the IRQ chip to
1841 * @lock_key: lockdep class for IRQ lock
1842 * @request_key: lockdep class for IRQ request
1844 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
1845 struct lock_class_key *lock_key,
1846 struct lock_class_key *request_key)
1848 struct irq_chip *irqchip = gpiochip->irq.chip;
1849 const struct irq_domain_ops *ops;
1850 struct device_node *np;
1857 if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {
1858 chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n");
1862 np = gpiochip->gpiodev->dev.of_node;
1863 type = gpiochip->irq.default_type;
1866 * Specifying a default trigger is a terrible idea if DT or ACPI is
1867 * used to configure the interrupts, as you may end up with
1868 * conflicting triggers. Tell the user, and reset to NONE.
1870 if (WARN(np && type != IRQ_TYPE_NONE,
1871 "%s: Ignoring %u default trigger\n", np->full_name, type))
1872 type = IRQ_TYPE_NONE;
1874 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1875 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1876 "Ignoring %u default trigger\n", type);
1877 type = IRQ_TYPE_NONE;
1880 gpiochip->to_irq = gpiochip_to_irq;
1881 gpiochip->irq.default_type = type;
1882 gpiochip->irq.lock_key = lock_key;
1883 gpiochip->irq.request_key = request_key;
1885 if (gpiochip->irq.domain_ops)
1886 ops = gpiochip->irq.domain_ops;
1888 ops = &gpiochip_domain_ops;
1890 gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
1891 gpiochip->irq.first,
1893 if (!gpiochip->irq.domain)
1897 * It is possible for a driver to override this, but only if the
1898 * alternative functions are both implemented.
1900 if (!irqchip->irq_request_resources &&
1901 !irqchip->irq_release_resources) {
1902 irqchip->irq_request_resources = gpiochip_irq_reqres;
1903 irqchip->irq_release_resources = gpiochip_irq_relres;
1906 if (gpiochip->irq.parent_handler) {
1907 void *data = gpiochip->irq.parent_handler_data ?: gpiochip;
1909 for (i = 0; i < gpiochip->irq.num_parents; i++) {
1911 * The parent IRQ chip is already using the chip_data
1912 * for this IRQ chip, so our callbacks simply use the
1915 irq_set_chained_handler_and_data(gpiochip->irq.parents[i],
1916 gpiochip->irq.parent_handler,
1921 acpi_gpiochip_request_interrupts(gpiochip);
1927 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1928 * @gpiochip: the gpiochip to remove the irqchip from
1930 * This is called only from gpiochip_remove()
1932 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1934 unsigned int offset;
1936 acpi_gpiochip_free_interrupts(gpiochip);
1938 if (gpiochip->irq.chip && gpiochip->irq.parent_handler) {
1939 struct gpio_irq_chip *irq = &gpiochip->irq;
1942 for (i = 0; i < irq->num_parents; i++)
1943 irq_set_chained_handler_and_data(irq->parents[i],
1947 /* Remove all IRQ mappings and delete the domain */
1948 if (gpiochip->irq.domain) {
1951 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1952 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1955 irq = irq_find_mapping(gpiochip->irq.domain, offset);
1956 irq_dispose_mapping(irq);
1959 irq_domain_remove(gpiochip->irq.domain);
1962 if (gpiochip->irq.chip) {
1963 gpiochip->irq.chip->irq_request_resources = NULL;
1964 gpiochip->irq.chip->irq_release_resources = NULL;
1965 gpiochip->irq.chip = NULL;
1968 gpiochip_irqchip_free_valid_mask(gpiochip);
1972 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
1973 * @gpiochip: the gpiochip to add the irqchip to
1974 * @irqchip: the irqchip to add to the gpiochip
1975 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1976 * allocate gpiochip irqs from
1977 * @handler: the irq handler to use (often a predefined irq core function)
1978 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1979 * to have the core avoid setting up any default type in the hardware.
1980 * @threaded: whether this irqchip uses a nested thread handler
1981 * @lock_key: lockdep class for IRQ lock
1982 * @request_key: lockdep class for IRQ request
1984 * This function closely associates a certain irqchip with a certain
1985 * gpiochip, providing an irq domain to translate the local IRQs to
1986 * global irqs in the gpiolib core, and making sure that the gpiochip
1987 * is passed as chip data to all related functions. Driver callbacks
1988 * need to use gpiochip_get_data() to get their local state containers back
1989 * from the gpiochip passed as chip data. An irqdomain will be stored
1990 * in the gpiochip that shall be used by the driver to handle IRQ number
1991 * translation. The gpiochip will need to be initialized and registered
1992 * before calling this function.
1994 * This function will handle two cell:ed simple IRQs and assumes all
1995 * the pins on the gpiochip can generate a unique IRQ. Everything else
1996 * need to be open coded.
1998 int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
1999 struct irq_chip *irqchip,
2000 unsigned int first_irq,
2001 irq_flow_handler_t handler,
2004 struct lock_class_key *lock_key,
2005 struct lock_class_key *request_key)
2007 struct device_node *of_node;
2009 if (!gpiochip || !irqchip)
2012 if (!gpiochip->parent) {
2013 pr_err("missing gpiochip .dev parent pointer\n");
2016 gpiochip->irq.threaded = threaded;
2017 of_node = gpiochip->parent->of_node;
2018 #ifdef CONFIG_OF_GPIO
2020 * If the gpiochip has an assigned OF node this takes precedence
2021 * FIXME: get rid of this and use gpiochip->parent->of_node
2024 if (gpiochip->of_node)
2025 of_node = gpiochip->of_node;
2028 * Specifying a default trigger is a terrible idea if DT or ACPI is
2029 * used to configure the interrupts, as you may end-up with
2030 * conflicting triggers. Tell the user, and reset to NONE.
2032 if (WARN(of_node && type != IRQ_TYPE_NONE,
2033 "%pOF: Ignoring %d default trigger\n", of_node, type))
2034 type = IRQ_TYPE_NONE;
2035 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
2036 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
2037 "Ignoring %d default trigger\n", type);
2038 type = IRQ_TYPE_NONE;
2041 gpiochip->irq.chip = irqchip;
2042 gpiochip->irq.handler = handler;
2043 gpiochip->irq.default_type = type;
2044 gpiochip->to_irq = gpiochip_to_irq;
2045 gpiochip->irq.lock_key = lock_key;
2046 gpiochip->irq.request_key = request_key;
2047 gpiochip->irq.domain = irq_domain_add_simple(of_node,
2048 gpiochip->ngpio, first_irq,
2049 &gpiochip_domain_ops, gpiochip);
2050 if (!gpiochip->irq.domain) {
2051 gpiochip->irq.chip = NULL;
2056 * It is possible for a driver to override this, but only if the
2057 * alternative functions are both implemented.
2059 if (!irqchip->irq_request_resources &&
2060 !irqchip->irq_release_resources) {
2061 irqchip->irq_request_resources = gpiochip_irq_reqres;
2062 irqchip->irq_release_resources = gpiochip_irq_relres;
2065 acpi_gpiochip_request_interrupts(gpiochip);
2069 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
2071 #else /* CONFIG_GPIOLIB_IRQCHIP */
2073 static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
2074 struct lock_class_key *lock_key,
2075 struct lock_class_key *request_key)
2080 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
2081 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
2085 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
2088 #endif /* CONFIG_GPIOLIB_IRQCHIP */
2091 * gpiochip_generic_request() - request the gpio function for a pin
2092 * @chip: the gpiochip owning the GPIO
2093 * @offset: the offset of the GPIO to request for GPIO function
2095 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
2097 return pinctrl_gpio_request(chip->gpiodev->base + offset);
2099 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2102 * gpiochip_generic_free() - free the gpio function from a pin
2103 * @chip: the gpiochip to request the gpio function for
2104 * @offset: the offset of the GPIO to free from GPIO function
2106 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
2108 pinctrl_gpio_free(chip->gpiodev->base + offset);
2110 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2113 * gpiochip_generic_config() - apply configuration for a pin
2114 * @chip: the gpiochip owning the GPIO
2115 * @offset: the offset of the GPIO to apply the configuration
2116 * @config: the configuration to be applied
2118 int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
2119 unsigned long config)
2121 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
2123 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2125 #ifdef CONFIG_PINCTRL
2128 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2129 * @chip: the gpiochip to add the range for
2130 * @pctldev: the pin controller to map to
2131 * @gpio_offset: the start offset in the current gpio_chip number space
2132 * @pin_group: name of the pin group inside the pin controller
2134 * Calling this function directly from a DeviceTree-supported
2135 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2136 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2137 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2139 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
2140 struct pinctrl_dev *pctldev,
2141 unsigned int gpio_offset, const char *pin_group)
2143 struct gpio_pin_range *pin_range;
2144 struct gpio_device *gdev = chip->gpiodev;
2147 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2149 chip_err(chip, "failed to allocate pin ranges\n");
2153 /* Use local offset as range ID */
2154 pin_range->range.id = gpio_offset;
2155 pin_range->range.gc = chip;
2156 pin_range->range.name = chip->label;
2157 pin_range->range.base = gdev->base + gpio_offset;
2158 pin_range->pctldev = pctldev;
2160 ret = pinctrl_get_group_pins(pctldev, pin_group,
2161 &pin_range->range.pins,
2162 &pin_range->range.npins);
2168 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2170 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2171 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2172 pinctrl_dev_get_devname(pctldev), pin_group);
2174 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2178 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2181 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2182 * @chip: the gpiochip to add the range for
2183 * @pinctl_name: the dev_name() of the pin controller to map to
2184 * @gpio_offset: the start offset in the current gpio_chip number space
2185 * @pin_offset: the start offset in the pin controller number space
2186 * @npins: the number of pins from the offset of each pin space (GPIO and
2187 * pin controller) to accumulate in this range
2190 * 0 on success, or a negative error-code on failure.
2192 * Calling this function directly from a DeviceTree-supported
2193 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2194 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2195 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2197 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
2198 unsigned int gpio_offset, unsigned int pin_offset,
2201 struct gpio_pin_range *pin_range;
2202 struct gpio_device *gdev = chip->gpiodev;
2205 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2207 chip_err(chip, "failed to allocate pin ranges\n");
2211 /* Use local offset as range ID */
2212 pin_range->range.id = gpio_offset;
2213 pin_range->range.gc = chip;
2214 pin_range->range.name = chip->label;
2215 pin_range->range.base = gdev->base + gpio_offset;
2216 pin_range->range.pin_base = pin_offset;
2217 pin_range->range.npins = npins;
2218 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2220 if (IS_ERR(pin_range->pctldev)) {
2221 ret = PTR_ERR(pin_range->pctldev);
2222 chip_err(chip, "could not create pin range\n");
2226 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2227 gpio_offset, gpio_offset + npins - 1,
2229 pin_offset, pin_offset + npins - 1);
2231 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2235 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2238 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2239 * @chip: the chip to remove all the mappings for
2241 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
2243 struct gpio_pin_range *pin_range, *tmp;
2244 struct gpio_device *gdev = chip->gpiodev;
2246 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2247 list_del(&pin_range->node);
2248 pinctrl_remove_gpio_range(pin_range->pctldev,
2253 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2255 #endif /* CONFIG_PINCTRL */
2257 /* These "optional" allocation calls help prevent drivers from stomping
2258 * on each other, and help provide better diagnostics in debugfs.
2259 * They're called even less than the "set direction" calls.
2261 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2263 struct gpio_chip *chip = desc->gdev->chip;
2265 unsigned long flags;
2267 spin_lock_irqsave(&gpio_lock, flags);
2269 /* NOTE: gpio_request() can be called in early boot,
2270 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2273 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2274 desc_set_label(desc, label ? : "?");
2281 if (chip->request) {
2282 /* chip->request may sleep */
2283 spin_unlock_irqrestore(&gpio_lock, flags);
2284 status = chip->request(chip, gpio_chip_hwgpio(desc));
2285 spin_lock_irqsave(&gpio_lock, flags);
2288 desc_set_label(desc, NULL);
2289 clear_bit(FLAG_REQUESTED, &desc->flags);
2293 if (chip->get_direction) {
2294 /* chip->get_direction may sleep */
2295 spin_unlock_irqrestore(&gpio_lock, flags);
2296 gpiod_get_direction(desc);
2297 spin_lock_irqsave(&gpio_lock, flags);
2300 spin_unlock_irqrestore(&gpio_lock, flags);
2305 * This descriptor validation needs to be inserted verbatim into each
2306 * function taking a descriptor, so we need to use a preprocessor
2307 * macro to avoid endless duplication. If the desc is NULL it is an
2308 * optional GPIO and calls should just bail out.
2310 static int validate_desc(const struct gpio_desc *desc, const char *func)
2315 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2316 return PTR_ERR(desc);
2319 pr_warn("%s: invalid GPIO (no device)\n", func);
2322 if (!desc->gdev->chip) {
2323 dev_warn(&desc->gdev->dev,
2324 "%s: backing chip is gone\n", func);
2330 #define VALIDATE_DESC(desc) do { \
2331 int __valid = validate_desc(desc, __func__); \
2336 #define VALIDATE_DESC_VOID(desc) do { \
2337 int __valid = validate_desc(desc, __func__); \
2342 int gpiod_request(struct gpio_desc *desc, const char *label)
2344 int status = -EPROBE_DEFER;
2345 struct gpio_device *gdev;
2347 VALIDATE_DESC(desc);
2350 if (try_module_get(gdev->owner)) {
2351 status = gpiod_request_commit(desc, label);
2353 module_put(gdev->owner);
2355 get_device(&gdev->dev);
2359 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2364 static bool gpiod_free_commit(struct gpio_desc *desc)
2367 unsigned long flags;
2368 struct gpio_chip *chip;
2372 gpiod_unexport(desc);
2374 spin_lock_irqsave(&gpio_lock, flags);
2376 chip = desc->gdev->chip;
2377 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2379 spin_unlock_irqrestore(&gpio_lock, flags);
2380 might_sleep_if(chip->can_sleep);
2381 chip->free(chip, gpio_chip_hwgpio(desc));
2382 spin_lock_irqsave(&gpio_lock, flags);
2384 desc_set_label(desc, NULL);
2385 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2386 clear_bit(FLAG_REQUESTED, &desc->flags);
2387 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2388 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2389 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2393 spin_unlock_irqrestore(&gpio_lock, flags);
2397 void gpiod_free(struct gpio_desc *desc)
2399 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2400 module_put(desc->gdev->owner);
2401 put_device(&desc->gdev->dev);
2403 WARN_ON(extra_checks);
2408 * gpiochip_is_requested - return string iff signal was requested
2409 * @chip: controller managing the signal
2410 * @offset: of signal within controller's 0..(ngpio - 1) range
2412 * Returns NULL if the GPIO is not currently requested, else a string.
2413 * The string returned is the label passed to gpio_request(); if none has been
2414 * passed it is a meaningless, non-NULL constant.
2416 * This function is for use by GPIO controller drivers. The label can
2417 * help with diagnostics, and knowing that the signal is used as a GPIO
2418 * can help avoid accidentally multiplexing it to another controller.
2420 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2422 struct gpio_desc *desc;
2424 if (offset >= chip->ngpio)
2427 desc = &chip->gpiodev->descs[offset];
2429 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2433 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2436 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2438 * @hwnum: hardware number of the GPIO for which to request the descriptor
2439 * @label: label for the GPIO
2441 * Function allows GPIO chip drivers to request and use their own GPIO
2442 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2443 * function will not increase reference count of the GPIO chip module. This
2444 * allows the GPIO chip module to be unloaded as needed (we assume that the
2445 * GPIO chip driver handles freeing the GPIOs it has requested).
2448 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2451 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2454 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2458 chip_err(chip, "failed to get GPIO descriptor\n");
2462 err = gpiod_request_commit(desc, label);
2464 return ERR_PTR(err);
2468 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2471 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2472 * @desc: GPIO descriptor to free
2474 * Function frees the given GPIO requested previously with
2475 * gpiochip_request_own_desc().
2477 void gpiochip_free_own_desc(struct gpio_desc *desc)
2480 gpiod_free_commit(desc);
2482 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2485 * Drivers MUST set GPIO direction before making get/set calls. In
2486 * some cases this is done in early boot, before IRQs are enabled.
2488 * As a rule these aren't called more than once (except for drivers
2489 * using the open-drain emulation idiom) so these are natural places
2490 * to accumulate extra debugging checks. Note that we can't (yet)
2491 * rely on gpio_request() having been called beforehand.
2495 * gpiod_direction_input - set the GPIO direction to input
2496 * @desc: GPIO to set to input
2498 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2499 * be called safely on it.
2501 * Return 0 in case of success, else an error code.
2503 int gpiod_direction_input(struct gpio_desc *desc)
2505 struct gpio_chip *chip;
2506 int status = -EINVAL;
2508 VALIDATE_DESC(desc);
2509 chip = desc->gdev->chip;
2511 if (!chip->get || !chip->direction_input) {
2513 "%s: missing get() or direction_input() operations\n",
2518 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2520 clear_bit(FLAG_IS_OUT, &desc->flags);
2522 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2526 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2528 static int gpio_set_drive_single_ended(struct gpio_chip *gc, unsigned offset,
2529 enum pin_config_param mode)
2531 unsigned long config = { PIN_CONF_PACKED(mode, 0) };
2533 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2536 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2538 struct gpio_chip *gc = desc->gdev->chip;
2542 if (!gc->set || !gc->direction_output) {
2544 "%s: missing set() or direction_output() operations\n",
2549 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2551 set_bit(FLAG_IS_OUT, &desc->flags);
2552 trace_gpio_value(desc_to_gpio(desc), 0, val);
2553 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2558 * gpiod_direction_output_raw - set the GPIO direction to output
2559 * @desc: GPIO to set to output
2560 * @value: initial output value of the GPIO
2562 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2563 * be called safely on it. The initial value of the output must be specified
2564 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2566 * Return 0 in case of success, else an error code.
2568 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2570 VALIDATE_DESC(desc);
2571 return gpiod_direction_output_raw_commit(desc, value);
2573 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2576 * gpiod_direction_output - set the GPIO direction to output
2577 * @desc: GPIO to set to output
2578 * @value: initial output value of the GPIO
2580 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2581 * be called safely on it. The initial value of the output must be specified
2582 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2585 * Return 0 in case of success, else an error code.
2587 int gpiod_direction_output(struct gpio_desc *desc, int value)
2589 struct gpio_chip *gc;
2592 VALIDATE_DESC(desc);
2593 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2598 /* GPIOs used for IRQs shall not be set as output */
2599 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
2601 "%s: tried to set a GPIO tied to an IRQ as output\n",
2606 gc = desc->gdev->chip;
2607 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2608 /* First see if we can enable open drain in hardware */
2609 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2610 PIN_CONFIG_DRIVE_OPEN_DRAIN);
2612 goto set_output_value;
2613 /* Emulate open drain by not actively driving the line high */
2615 return gpiod_direction_input(desc);
2617 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2618 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2619 PIN_CONFIG_DRIVE_OPEN_SOURCE);
2621 goto set_output_value;
2622 /* Emulate open source by not actively driving the line low */
2624 return gpiod_direction_input(desc);
2626 gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2627 PIN_CONFIG_DRIVE_PUSH_PULL);
2631 return gpiod_direction_output_raw_commit(desc, value);
2633 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2636 * gpiod_set_debounce - sets @debounce time for a GPIO
2637 * @desc: descriptor of the GPIO for which to set debounce time
2638 * @debounce: debounce time in microseconds
2641 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2644 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2646 struct gpio_chip *chip;
2647 unsigned long config;
2649 VALIDATE_DESC(desc);
2650 chip = desc->gdev->chip;
2651 if (!chip->set || !chip->set_config) {
2653 "%s: missing set() or set_config() operations\n",
2658 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2659 return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
2661 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2664 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2665 * @desc: descriptor of the GPIO for which to configure persistence
2666 * @transitory: True to lose state on suspend or reset, false for persistence
2669 * 0 on success, otherwise a negative error code.
2671 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2673 struct gpio_chip *chip;
2674 unsigned long packed;
2678 VALIDATE_DESC(desc);
2680 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2681 * persistence state.
2684 set_bit(FLAG_TRANSITORY, &desc->flags);
2686 clear_bit(FLAG_TRANSITORY, &desc->flags);
2688 /* If the driver supports it, set the persistence state now */
2689 chip = desc->gdev->chip;
2690 if (!chip->set_config)
2693 packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
2695 gpio = gpio_chip_hwgpio(desc);
2696 rc = chip->set_config(chip, gpio, packed);
2697 if (rc == -ENOTSUPP) {
2698 dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
2705 EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2708 * gpiod_is_active_low - test whether a GPIO is active-low or not
2709 * @desc: the gpio descriptor to test
2711 * Returns 1 if the GPIO is active-low, 0 otherwise.
2713 int gpiod_is_active_low(const struct gpio_desc *desc)
2715 VALIDATE_DESC(desc);
2716 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2718 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2720 /* I/O calls are only valid after configuration completed; the relevant
2721 * "is this a valid GPIO" error checks should already have been done.
2723 * "Get" operations are often inlinable as reading a pin value register,
2724 * and masking the relevant bit in that register.
2726 * When "set" operations are inlinable, they involve writing that mask to
2727 * one register to set a low value, or a different register to set it high.
2728 * Otherwise locking is needed, so there may be little value to inlining.
2730 *------------------------------------------------------------------------
2732 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2733 * have requested the GPIO. That can include implicit requesting by
2734 * a direction setting call. Marking a gpio as requested locks its chip
2735 * in memory, guaranteeing that these table lookups need no more locking
2736 * and that gpiochip_remove() will fail.
2738 * REVISIT when debugging, consider adding some instrumentation to ensure
2739 * that the GPIO was actually requested.
2742 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2744 struct gpio_chip *chip;
2748 chip = desc->gdev->chip;
2749 offset = gpio_chip_hwgpio(desc);
2750 value = chip->get ? chip->get(chip, offset) : -EIO;
2751 value = value < 0 ? value : !!value;
2752 trace_gpio_value(desc_to_gpio(desc), 1, value);
2756 static int gpio_chip_get_multiple(struct gpio_chip *chip,
2757 unsigned long *mask, unsigned long *bits)
2759 if (chip->get_multiple) {
2760 return chip->get_multiple(chip, mask, bits);
2761 } else if (chip->get) {
2764 for_each_set_bit(i, mask, chip->ngpio) {
2765 value = chip->get(chip, i);
2768 __assign_bit(i, bits, value);
2775 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2776 unsigned int array_size,
2777 struct gpio_desc **desc_array,
2782 while (i < array_size) {
2783 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2784 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
2785 unsigned long *mask, *bits;
2788 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
2791 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
2793 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
2798 bits = mask + BITS_TO_LONGS(chip->ngpio);
2799 bitmap_zero(mask, chip->ngpio);
2802 WARN_ON(chip->can_sleep);
2804 /* collect all inputs belonging to the same chip */
2807 const struct gpio_desc *desc = desc_array[i];
2808 int hwgpio = gpio_chip_hwgpio(desc);
2810 __set_bit(hwgpio, mask);
2812 } while ((i < array_size) &&
2813 (desc_array[i]->gdev->chip == chip));
2815 ret = gpio_chip_get_multiple(chip, mask, bits);
2817 if (mask != fastpath)
2822 for (j = first; j < i; j++) {
2823 const struct gpio_desc *desc = desc_array[j];
2824 int hwgpio = gpio_chip_hwgpio(desc);
2825 int value = test_bit(hwgpio, bits);
2827 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2829 value_array[j] = value;
2830 trace_gpio_value(desc_to_gpio(desc), 1, value);
2833 if (mask != fastpath)
2840 * gpiod_get_raw_value() - return a gpio's raw value
2841 * @desc: gpio whose value will be returned
2843 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2844 * its ACTIVE_LOW status, or negative errno on failure.
2846 * This function should be called from contexts where we cannot sleep, and will
2847 * complain if the GPIO chip functions potentially sleep.
2849 int gpiod_get_raw_value(const struct gpio_desc *desc)
2851 VALIDATE_DESC(desc);
2852 /* Should be using gpio_get_value_cansleep() */
2853 WARN_ON(desc->gdev->chip->can_sleep);
2854 return gpiod_get_raw_value_commit(desc);
2856 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2859 * gpiod_get_value() - return a gpio's value
2860 * @desc: gpio whose value will be returned
2862 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2863 * account, or negative errno on failure.
2865 * This function should be called from contexts where we cannot sleep, and will
2866 * complain if the GPIO chip functions potentially sleep.
2868 int gpiod_get_value(const struct gpio_desc *desc)
2872 VALIDATE_DESC(desc);
2873 /* Should be using gpio_get_value_cansleep() */
2874 WARN_ON(desc->gdev->chip->can_sleep);
2876 value = gpiod_get_raw_value_commit(desc);
2880 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2885 EXPORT_SYMBOL_GPL(gpiod_get_value);
2888 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
2889 * @array_size: number of elements in the descriptor / value arrays
2890 * @desc_array: array of GPIO descriptors whose values will be read
2891 * @value_array: array to store the read values
2893 * Read the raw values of the GPIOs, i.e. the values of the physical lines
2894 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
2895 * else an error code.
2897 * This function should be called from contexts where we cannot sleep,
2898 * and it will complain if the GPIO chip functions potentially sleep.
2900 int gpiod_get_raw_array_value(unsigned int array_size,
2901 struct gpio_desc **desc_array, int *value_array)
2905 return gpiod_get_array_value_complex(true, false, array_size,
2906 desc_array, value_array);
2908 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
2911 * gpiod_get_array_value() - read values from an array of GPIOs
2912 * @array_size: number of elements in the descriptor / value arrays
2913 * @desc_array: array of GPIO descriptors whose values will be read
2914 * @value_array: array to store the read values
2916 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2917 * into account. Return 0 in case of success, else an error code.
2919 * This function should be called from contexts where we cannot sleep,
2920 * and it will complain if the GPIO chip functions potentially sleep.
2922 int gpiod_get_array_value(unsigned int array_size,
2923 struct gpio_desc **desc_array, int *value_array)
2927 return gpiod_get_array_value_complex(false, false, array_size,
2928 desc_array, value_array);
2930 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
2933 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
2934 * @desc: gpio descriptor whose state need to be set.
2935 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2937 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
2940 struct gpio_chip *chip = desc->gdev->chip;
2941 int offset = gpio_chip_hwgpio(desc);
2944 err = chip->direction_input(chip, offset);
2946 clear_bit(FLAG_IS_OUT, &desc->flags);
2948 err = chip->direction_output(chip, offset, 0);
2950 set_bit(FLAG_IS_OUT, &desc->flags);
2952 trace_gpio_direction(desc_to_gpio(desc), value, err);
2955 "%s: Error in set_value for open drain err %d\n",
2960 * _gpio_set_open_source_value() - Set the open source gpio's value.
2961 * @desc: gpio descriptor whose state need to be set.
2962 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2964 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
2967 struct gpio_chip *chip = desc->gdev->chip;
2968 int offset = gpio_chip_hwgpio(desc);
2971 err = chip->direction_output(chip, offset, 1);
2973 set_bit(FLAG_IS_OUT, &desc->flags);
2975 err = chip->direction_input(chip, offset);
2977 clear_bit(FLAG_IS_OUT, &desc->flags);
2979 trace_gpio_direction(desc_to_gpio(desc), !value, err);
2982 "%s: Error in set_value for open source err %d\n",
2986 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
2988 struct gpio_chip *chip;
2990 chip = desc->gdev->chip;
2991 trace_gpio_value(desc_to_gpio(desc), 0, value);
2992 chip->set(chip, gpio_chip_hwgpio(desc), value);
2996 * set multiple outputs on the same chip;
2997 * use the chip's set_multiple function if available;
2998 * otherwise set the outputs sequentially;
2999 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3000 * defines which outputs are to be changed
3001 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3002 * defines the values the outputs specified by mask are to be set to
3004 static void gpio_chip_set_multiple(struct gpio_chip *chip,
3005 unsigned long *mask, unsigned long *bits)
3007 if (chip->set_multiple) {
3008 chip->set_multiple(chip, mask, bits);
3012 /* set outputs if the corresponding mask bit is set */
3013 for_each_set_bit(i, mask, chip->ngpio)
3014 chip->set(chip, i, test_bit(i, bits));
3018 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3019 unsigned int array_size,
3020 struct gpio_desc **desc_array,
3025 while (i < array_size) {
3026 struct gpio_chip *chip = desc_array[i]->gdev->chip;
3027 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
3028 unsigned long *mask, *bits;
3031 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
3034 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
3036 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
3041 bits = mask + BITS_TO_LONGS(chip->ngpio);
3042 bitmap_zero(mask, chip->ngpio);
3045 WARN_ON(chip->can_sleep);
3048 struct gpio_desc *desc = desc_array[i];
3049 int hwgpio = gpio_chip_hwgpio(desc);
3050 int value = value_array[i];
3052 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3054 trace_gpio_value(desc_to_gpio(desc), 0, value);
3056 * collect all normal outputs belonging to the same chip
3057 * open drain and open source outputs are set individually
3059 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3060 gpio_set_open_drain_value_commit(desc, value);
3061 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3062 gpio_set_open_source_value_commit(desc, value);
3064 __set_bit(hwgpio, mask);
3066 __set_bit(hwgpio, bits);
3068 __clear_bit(hwgpio, bits);
3072 } while ((i < array_size) &&
3073 (desc_array[i]->gdev->chip == chip));
3074 /* push collected bits to outputs */
3076 gpio_chip_set_multiple(chip, mask, bits);
3078 if (mask != fastpath)
3085 * gpiod_set_raw_value() - assign a gpio's raw value
3086 * @desc: gpio whose value will be assigned
3087 * @value: value to assign
3089 * Set the raw value of the GPIO, i.e. the value of its physical line without
3090 * regard for its ACTIVE_LOW status.
3092 * This function should be called from contexts where we cannot sleep, and will
3093 * complain if the GPIO chip functions potentially sleep.
3095 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3097 VALIDATE_DESC_VOID(desc);
3098 /* Should be using gpiod_set_value_cansleep() */
3099 WARN_ON(desc->gdev->chip->can_sleep);
3100 gpiod_set_raw_value_commit(desc, value);
3102 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3105 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3106 * @desc: the descriptor to set the value on
3107 * @value: value to set
3109 * This sets the value of a GPIO line backing a descriptor, applying
3110 * different semantic quirks like active low and open drain/source
3113 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3115 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3117 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3118 gpio_set_open_drain_value_commit(desc, value);
3119 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3120 gpio_set_open_source_value_commit(desc, value);
3122 gpiod_set_raw_value_commit(desc, value);
3126 * gpiod_set_value() - assign a gpio's value
3127 * @desc: gpio whose value will be assigned
3128 * @value: value to assign
3130 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3131 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3133 * This function should be called from contexts where we cannot sleep, and will
3134 * complain if the GPIO chip functions potentially sleep.
3136 void gpiod_set_value(struct gpio_desc *desc, int value)
3138 VALIDATE_DESC_VOID(desc);
3139 WARN_ON(desc->gdev->chip->can_sleep);
3140 gpiod_set_value_nocheck(desc, value);
3142 EXPORT_SYMBOL_GPL(gpiod_set_value);
3145 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3146 * @array_size: number of elements in the descriptor / value arrays
3147 * @desc_array: array of GPIO descriptors whose values will be assigned
3148 * @value_array: array of values to assign
3150 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3151 * without regard for their ACTIVE_LOW status.
3153 * This function should be called from contexts where we cannot sleep, and will
3154 * complain if the GPIO chip functions potentially sleep.
3156 int gpiod_set_raw_array_value(unsigned int array_size,
3157 struct gpio_desc **desc_array, int *value_array)
3161 return gpiod_set_array_value_complex(true, false, array_size,
3162 desc_array, value_array);
3164 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3167 * gpiod_set_array_value() - assign values to an array of GPIOs
3168 * @array_size: number of elements in the descriptor / value arrays
3169 * @desc_array: array of GPIO descriptors whose values will be assigned
3170 * @value_array: array of values to assign
3172 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3175 * This function should be called from contexts where we cannot sleep, and will
3176 * complain if the GPIO chip functions potentially sleep.
3178 void gpiod_set_array_value(unsigned int array_size,
3179 struct gpio_desc **desc_array, int *value_array)
3183 gpiod_set_array_value_complex(false, false, array_size, desc_array,
3186 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3189 * gpiod_cansleep() - report whether gpio value access may sleep
3190 * @desc: gpio to check
3193 int gpiod_cansleep(const struct gpio_desc *desc)
3195 VALIDATE_DESC(desc);
3196 return desc->gdev->chip->can_sleep;
3198 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3201 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3202 * @desc: gpio to set the consumer name on
3203 * @name: the new consumer name
3205 void gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3207 VALIDATE_DESC_VOID(desc);
3208 /* Just overwrite whatever the previous name was */
3211 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3214 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3215 * @desc: gpio whose IRQ will be returned (already requested)
3217 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3220 int gpiod_to_irq(const struct gpio_desc *desc)
3222 struct gpio_chip *chip;
3226 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3227 * requires this function to not return zero on an invalid descriptor
3228 * but rather a negative error number.
3230 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3233 chip = desc->gdev->chip;
3234 offset = gpio_chip_hwgpio(desc);
3236 int retirq = chip->to_irq(chip, offset);
3238 /* Zero means NO_IRQ */
3246 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3249 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3250 * @chip: the chip the GPIO to lock belongs to
3251 * @offset: the offset of the GPIO to lock as IRQ
3253 * This is used directly by GPIO drivers that want to lock down
3254 * a certain GPIO line to be used for IRQs.
3256 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
3258 struct gpio_desc *desc;
3260 desc = gpiochip_get_desc(chip, offset);
3262 return PTR_ERR(desc);
3265 * If it's fast: flush the direction setting if something changed
3268 if (!chip->can_sleep && chip->get_direction) {
3269 int dir = gpiod_get_direction(desc);
3272 chip_err(chip, "%s: cannot get GPIO direction\n",
3278 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
3280 "%s: tried to flag a GPIO set as output for IRQ\n",
3285 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3288 * If the consumer has not set up a label (such as when the
3289 * IRQ is referenced from .to_irq()) we set up a label here
3290 * so it is clear this is used as an interrupt.
3293 desc_set_label(desc, "interrupt");
3297 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3300 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3301 * @chip: the chip the GPIO to lock belongs to
3302 * @offset: the offset of the GPIO to lock as IRQ
3304 * This is used directly by GPIO drivers that want to indicate
3305 * that a certain GPIO is no longer used exclusively for IRQ.
3307 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
3309 struct gpio_desc *desc;
3311 desc = gpiochip_get_desc(chip, offset);
3315 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3317 /* If we only had this marking, erase it */
3318 if (desc->label && !strcmp(desc->label, "interrupt"))
3319 desc_set_label(desc, NULL);
3321 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3323 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
3325 if (offset >= chip->ngpio)
3328 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
3330 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3332 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
3334 if (offset >= chip->ngpio)
3337 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
3339 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3341 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
3343 if (offset >= chip->ngpio)
3346 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
3348 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3350 bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
3352 if (offset >= chip->ngpio)
3355 return !test_bit(FLAG_TRANSITORY, &chip->gpiodev->descs[offset].flags);
3357 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3360 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3361 * @desc: gpio whose value will be returned
3363 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3364 * its ACTIVE_LOW status, or negative errno on failure.
3366 * This function is to be called from contexts that can sleep.
3368 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3370 might_sleep_if(extra_checks);
3371 VALIDATE_DESC(desc);
3372 return gpiod_get_raw_value_commit(desc);
3374 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3377 * gpiod_get_value_cansleep() - return a gpio's value
3378 * @desc: gpio whose value will be returned
3380 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3381 * account, or negative errno on failure.
3383 * This function is to be called from contexts that can sleep.
3385 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3389 might_sleep_if(extra_checks);
3390 VALIDATE_DESC(desc);
3391 value = gpiod_get_raw_value_commit(desc);
3395 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3400 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3403 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3404 * @array_size: number of elements in the descriptor / value arrays
3405 * @desc_array: array of GPIO descriptors whose values will be read
3406 * @value_array: array to store the read values
3408 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3409 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3410 * else an error code.
3412 * This function is to be called from contexts that can sleep.
3414 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3415 struct gpio_desc **desc_array,
3418 might_sleep_if(extra_checks);
3421 return gpiod_get_array_value_complex(true, true, array_size,
3422 desc_array, value_array);
3424 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3427 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3428 * @array_size: number of elements in the descriptor / value arrays
3429 * @desc_array: array of GPIO descriptors whose values will be read
3430 * @value_array: array to store the read values
3432 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3433 * into account. Return 0 in case of success, else an error code.
3435 * This function is to be called from contexts that can sleep.
3437 int gpiod_get_array_value_cansleep(unsigned int array_size,
3438 struct gpio_desc **desc_array,
3441 might_sleep_if(extra_checks);
3444 return gpiod_get_array_value_complex(false, true, array_size,
3445 desc_array, value_array);
3447 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3450 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3451 * @desc: gpio whose value will be assigned
3452 * @value: value to assign
3454 * Set the raw value of the GPIO, i.e. the value of its physical line without
3455 * regard for its ACTIVE_LOW status.
3457 * This function is to be called from contexts that can sleep.
3459 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3461 might_sleep_if(extra_checks);
3462 VALIDATE_DESC_VOID(desc);
3463 gpiod_set_raw_value_commit(desc, value);
3465 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3468 * gpiod_set_value_cansleep() - assign a gpio's value
3469 * @desc: gpio whose value will be assigned
3470 * @value: value to assign
3472 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3475 * This function is to be called from contexts that can sleep.
3477 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3479 might_sleep_if(extra_checks);
3480 VALIDATE_DESC_VOID(desc);
3481 gpiod_set_value_nocheck(desc, value);
3483 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3486 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3487 * @array_size: number of elements in the descriptor / value arrays
3488 * @desc_array: array of GPIO descriptors whose values will be assigned
3489 * @value_array: array of values to assign
3491 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3492 * without regard for their ACTIVE_LOW status.
3494 * This function is to be called from contexts that can sleep.
3496 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3497 struct gpio_desc **desc_array,
3500 might_sleep_if(extra_checks);
3503 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3506 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3509 * gpiod_add_lookup_tables() - register GPIO device consumers
3510 * @tables: list of tables of consumers to register
3511 * @n: number of tables in the list
3513 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3517 mutex_lock(&gpio_lookup_lock);
3519 for (i = 0; i < n; i++)
3520 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3522 mutex_unlock(&gpio_lookup_lock);
3526 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3527 * @array_size: number of elements in the descriptor / value arrays
3528 * @desc_array: array of GPIO descriptors whose values will be assigned
3529 * @value_array: array of values to assign
3531 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3534 * This function is to be called from contexts that can sleep.
3536 void gpiod_set_array_value_cansleep(unsigned int array_size,
3537 struct gpio_desc **desc_array,
3540 might_sleep_if(extra_checks);
3543 gpiod_set_array_value_complex(false, true, array_size, desc_array,
3546 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3549 * gpiod_add_lookup_table() - register GPIO device consumers
3550 * @table: table of consumers to register
3552 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3554 mutex_lock(&gpio_lookup_lock);
3556 list_add_tail(&table->list, &gpio_lookup_list);
3558 mutex_unlock(&gpio_lookup_lock);
3560 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3563 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3564 * @table: table of consumers to unregister
3566 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3568 mutex_lock(&gpio_lookup_lock);
3570 list_del(&table->list);
3572 mutex_unlock(&gpio_lookup_lock);
3574 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3577 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
3578 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
3580 void gpiod_add_hogs(struct gpiod_hog *hogs)
3582 struct gpio_chip *chip;
3583 struct gpiod_hog *hog;
3585 mutex_lock(&gpio_machine_hogs_mutex);
3587 for (hog = &hogs[0]; hog->chip_label; hog++) {
3588 list_add_tail(&hog->list, &gpio_machine_hogs);
3591 * The chip may have been registered earlier, so check if it
3592 * exists and, if so, try to hog the line now.
3594 chip = find_chip_by_name(hog->chip_label);
3596 gpiochip_machine_hog(chip, hog);
3599 mutex_unlock(&gpio_machine_hogs_mutex);
3601 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
3603 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3605 const char *dev_id = dev ? dev_name(dev) : NULL;
3606 struct gpiod_lookup_table *table;
3608 mutex_lock(&gpio_lookup_lock);
3610 list_for_each_entry(table, &gpio_lookup_list, list) {
3611 if (table->dev_id && dev_id) {
3613 * Valid strings on both ends, must be identical to have
3616 if (!strcmp(table->dev_id, dev_id))
3620 * One of the pointers is NULL, so both must be to have
3623 if (dev_id == table->dev_id)
3630 mutex_unlock(&gpio_lookup_lock);
3634 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3636 enum gpio_lookup_flags *flags)
3638 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3639 struct gpiod_lookup_table *table;
3640 struct gpiod_lookup *p;
3642 table = gpiod_find_lookup_table(dev);
3646 for (p = &table->table[0]; p->chip_label; p++) {
3647 struct gpio_chip *chip;
3649 /* idx must always match exactly */
3653 /* If the lookup entry has a con_id, require exact match */
3654 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3657 chip = find_chip_by_name(p->chip_label);
3661 * As the lookup table indicates a chip with
3662 * p->chip_label should exist, assume it may
3663 * still appear later and let the interested
3664 * consumer be probed again or let the Deferred
3665 * Probe infrastructure handle the error.
3667 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
3669 return ERR_PTR(-EPROBE_DEFER);
3672 if (chip->ngpio <= p->chip_hwnum) {
3674 "requested GPIO %d is out of range [0..%d] for chip %s\n",
3675 idx, chip->ngpio, chip->label);
3676 return ERR_PTR(-EINVAL);
3679 desc = gpiochip_get_desc(chip, p->chip_hwnum);
3688 static int dt_gpio_count(struct device *dev, const char *con_id)
3694 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3696 snprintf(propname, sizeof(propname), "%s-%s",
3697 con_id, gpio_suffixes[i]);
3699 snprintf(propname, sizeof(propname), "%s",
3702 ret = of_gpio_named_count(dev->of_node, propname);
3706 return ret ? ret : -ENOENT;
3709 static int platform_gpio_count(struct device *dev, const char *con_id)
3711 struct gpiod_lookup_table *table;
3712 struct gpiod_lookup *p;
3713 unsigned int count = 0;
3715 table = gpiod_find_lookup_table(dev);
3719 for (p = &table->table[0]; p->chip_label; p++) {
3720 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3721 (!con_id && !p->con_id))
3731 * gpiod_count - return the number of GPIOs associated with a device / function
3732 * or -ENOENT if no GPIO has been assigned to the requested function
3733 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3734 * @con_id: function within the GPIO consumer
3736 int gpiod_count(struct device *dev, const char *con_id)
3738 int count = -ENOENT;
3740 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
3741 count = dt_gpio_count(dev, con_id);
3742 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
3743 count = acpi_gpio_count(dev, con_id);
3746 count = platform_gpio_count(dev, con_id);
3750 EXPORT_SYMBOL_GPL(gpiod_count);
3753 * gpiod_get - obtain a GPIO for a given GPIO function
3754 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3755 * @con_id: function within the GPIO consumer
3756 * @flags: optional GPIO initialization flags
3758 * Return the GPIO descriptor corresponding to the function con_id of device
3759 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3760 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3762 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3763 enum gpiod_flags flags)
3765 return gpiod_get_index(dev, con_id, 0, flags);
3767 EXPORT_SYMBOL_GPL(gpiod_get);
3770 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3771 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3772 * @con_id: function within the GPIO consumer
3773 * @flags: optional GPIO initialization flags
3775 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3776 * the requested function it will return NULL. This is convenient for drivers
3777 * that need to handle optional GPIOs.
3779 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3781 enum gpiod_flags flags)
3783 return gpiod_get_index_optional(dev, con_id, 0, flags);
3785 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3789 * gpiod_configure_flags - helper function to configure a given GPIO
3790 * @desc: gpio whose value will be assigned
3791 * @con_id: function within the GPIO consumer
3792 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3794 * @dflags: gpiod_flags - optional GPIO initialization flags
3796 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3797 * requested function and/or index, or another IS_ERR() code if an error
3798 * occurred while trying to acquire the GPIO.
3800 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3801 unsigned long lflags, enum gpiod_flags dflags)
3805 if (lflags & GPIO_ACTIVE_LOW)
3806 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3808 if (lflags & GPIO_OPEN_DRAIN)
3809 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3810 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
3812 * This enforces open drain mode from the consumer side.
3813 * This is necessary for some busses like I2C, but the lookup
3814 * should *REALLY* have specified them as open drain in the
3815 * first place, so print a little warning here.
3817 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3819 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
3822 if (lflags & GPIO_OPEN_SOURCE)
3823 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3825 status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
3829 /* No particular flag request, return here... */
3830 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3831 pr_debug("no flags found for %s\n", con_id);
3836 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3837 status = gpiod_direction_output(desc,
3838 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3840 status = gpiod_direction_input(desc);
3846 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3847 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3848 * @con_id: function within the GPIO consumer
3849 * @idx: index of the GPIO to obtain in the consumer
3850 * @flags: optional GPIO initialization flags
3852 * This variant of gpiod_get() allows to access GPIOs other than the first
3853 * defined one for functions that define several GPIOs.
3855 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3856 * requested function and/or index, or another IS_ERR() code if an error
3857 * occurred while trying to acquire the GPIO.
3859 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3862 enum gpiod_flags flags)
3864 struct gpio_desc *desc = NULL;
3866 enum gpio_lookup_flags lookupflags = 0;
3867 /* Maybe we have a device name, maybe not */
3868 const char *devname = dev ? dev_name(dev) : "?";
3870 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3873 /* Using device tree? */
3874 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
3875 dev_dbg(dev, "using device tree for GPIO lookup\n");
3876 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3877 } else if (ACPI_COMPANION(dev)) {
3878 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3879 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
3884 * Either we are not using DT or ACPI, or their lookup did not return
3885 * a result. In that case, use platform lookup as a fallback.
3887 if (!desc || desc == ERR_PTR(-ENOENT)) {
3888 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3889 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3893 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
3898 * If a connection label was passed use that, else attempt to use
3899 * the device name as label
3901 status = gpiod_request(desc, con_id ? con_id : devname);
3903 return ERR_PTR(status);
3905 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3907 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3909 return ERR_PTR(status);
3914 EXPORT_SYMBOL_GPL(gpiod_get_index);
3917 * gpiod_get_from_of_node() - obtain a GPIO from an OF node
3918 * @node: handle of the OF node
3919 * @propname: name of the DT property representing the GPIO
3920 * @index: index of the GPIO to obtain for the consumer
3921 * @dflags: GPIO initialization flags
3922 * @label: label to attach to the requested GPIO
3925 * On successful request the GPIO pin is configured in accordance with
3926 * provided @dflags. If the node does not have the requested GPIO
3927 * property, NULL is returned.
3929 * In case of error an ERR_PTR() is returned.
3931 struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
3932 const char *propname, int index,
3933 enum gpiod_flags dflags,
3936 struct gpio_desc *desc;
3937 unsigned long lflags = 0;
3938 enum of_gpio_flags flags;
3939 bool active_low = false;
3940 bool single_ended = false;
3941 bool open_drain = false;
3942 bool transitory = false;
3945 desc = of_get_named_gpiod_flags(node, propname,
3948 if (!desc || IS_ERR(desc)) {
3949 /* If it is not there, just return NULL */
3950 if (PTR_ERR(desc) == -ENOENT)
3955 active_low = flags & OF_GPIO_ACTIVE_LOW;
3956 single_ended = flags & OF_GPIO_SINGLE_ENDED;
3957 open_drain = flags & OF_GPIO_OPEN_DRAIN;
3958 transitory = flags & OF_GPIO_TRANSITORY;
3960 ret = gpiod_request(desc, label);
3962 return ERR_PTR(ret);
3965 lflags |= GPIO_ACTIVE_LOW;
3969 lflags |= GPIO_OPEN_DRAIN;
3971 lflags |= GPIO_OPEN_SOURCE;
3975 lflags |= GPIO_TRANSITORY;
3977 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
3980 return ERR_PTR(ret);
3985 EXPORT_SYMBOL(gpiod_get_from_of_node);
3988 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3989 * @fwnode: handle of the firmware node
3990 * @propname: name of the firmware property representing the GPIO
3991 * @index: index of the GPIO to obtain for the consumer
3992 * @dflags: GPIO initialization flags
3993 * @label: label to attach to the requested GPIO
3995 * This function can be used for drivers that get their configuration
3996 * from opaque firmware.
3998 * The function properly finds the corresponding GPIO using whatever is the
3999 * underlying firmware interface and then makes sure that the GPIO
4000 * descriptor is requested before it is returned to the caller.
4003 * On successful request the GPIO pin is configured in accordance with
4006 * In case of error an ERR_PTR() is returned.
4008 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
4009 const char *propname, int index,
4010 enum gpiod_flags dflags,
4013 struct gpio_desc *desc = ERR_PTR(-ENODEV);
4014 unsigned long lflags = 0;
4018 return ERR_PTR(-EINVAL);
4020 if (is_of_node(fwnode)) {
4021 desc = gpiod_get_from_of_node(to_of_node(fwnode),
4026 } else if (is_acpi_node(fwnode)) {
4027 struct acpi_gpio_info info;
4029 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4033 acpi_gpio_update_gpiod_flags(&dflags, &info);
4035 if (info.polarity == GPIO_ACTIVE_LOW)
4036 lflags |= GPIO_ACTIVE_LOW;
4039 /* Currently only ACPI takes this path */
4040 ret = gpiod_request(desc, label);
4042 return ERR_PTR(ret);
4044 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4047 return ERR_PTR(ret);
4052 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4055 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4057 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4058 * @con_id: function within the GPIO consumer
4059 * @index: index of the GPIO to obtain in the consumer
4060 * @flags: optional GPIO initialization flags
4062 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4063 * specified index was assigned to the requested function it will return NULL.
4064 * This is convenient for drivers that need to handle optional GPIOs.
4066 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4069 enum gpiod_flags flags)
4071 struct gpio_desc *desc;
4073 desc = gpiod_get_index(dev, con_id, index, flags);
4075 if (PTR_ERR(desc) == -ENOENT)
4081 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4084 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4085 * @desc: gpio whose value will be assigned
4086 * @name: gpio line name
4087 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
4089 * @dflags: gpiod_flags - optional GPIO initialization flags
4091 int gpiod_hog(struct gpio_desc *desc, const char *name,
4092 unsigned long lflags, enum gpiod_flags dflags)
4094 struct gpio_chip *chip;
4095 struct gpio_desc *local_desc;
4099 chip = gpiod_to_chip(desc);
4100 hwnum = gpio_chip_hwgpio(desc);
4102 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
4103 if (IS_ERR(local_desc)) {
4104 status = PTR_ERR(local_desc);
4105 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4106 name, chip->label, hwnum, status);
4110 status = gpiod_configure_flags(desc, name, lflags, dflags);
4112 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
4113 name, chip->label, hwnum, status);
4114 gpiochip_free_own_desc(desc);
4118 /* Mark GPIO as hogged so it can be identified and removed later */
4119 set_bit(FLAG_IS_HOGGED, &desc->flags);
4121 pr_info("GPIO line %d (%s) hogged as %s%s\n",
4122 desc_to_gpio(desc), name,
4123 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4124 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
4125 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
4131 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4132 * @chip: gpio chip to act on
4134 * This is only used by of_gpiochip_remove to free hogged gpios
4136 static void gpiochip_free_hogs(struct gpio_chip *chip)
4140 for (id = 0; id < chip->ngpio; id++) {
4141 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
4142 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
4147 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4148 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4149 * @con_id: function within the GPIO consumer
4150 * @flags: optional GPIO initialization flags
4152 * This function acquires all the GPIOs defined under a given function.
4154 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4155 * no GPIO has been assigned to the requested function, or another IS_ERR()
4156 * code if an error occurred while trying to acquire the GPIOs.
4158 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4160 enum gpiod_flags flags)
4162 struct gpio_desc *desc;
4163 struct gpio_descs *descs;
4166 count = gpiod_count(dev, con_id);
4168 return ERR_PTR(count);
4170 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4172 return ERR_PTR(-ENOMEM);
4174 for (descs->ndescs = 0; descs->ndescs < count; ) {
4175 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4177 gpiod_put_array(descs);
4178 return ERR_CAST(desc);
4180 descs->desc[descs->ndescs] = desc;
4185 EXPORT_SYMBOL_GPL(gpiod_get_array);
4188 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4190 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4191 * @con_id: function within the GPIO consumer
4192 * @flags: optional GPIO initialization flags
4194 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4195 * assigned to the requested function it will return NULL.
4197 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4199 enum gpiod_flags flags)
4201 struct gpio_descs *descs;
4203 descs = gpiod_get_array(dev, con_id, flags);
4204 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
4209 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4212 * gpiod_put - dispose of a GPIO descriptor
4213 * @desc: GPIO descriptor to dispose of
4215 * No descriptor can be used after gpiod_put() has been called on it.
4217 void gpiod_put(struct gpio_desc *desc)
4221 EXPORT_SYMBOL_GPL(gpiod_put);
4224 * gpiod_put_array - dispose of multiple GPIO descriptors
4225 * @descs: struct gpio_descs containing an array of descriptors
4227 void gpiod_put_array(struct gpio_descs *descs)
4231 for (i = 0; i < descs->ndescs; i++)
4232 gpiod_put(descs->desc[i]);
4236 EXPORT_SYMBOL_GPL(gpiod_put_array);
4238 static int __init gpiolib_dev_init(void)
4242 /* Register GPIO sysfs bus */
4243 ret = bus_register(&gpio_bus_type);
4245 pr_err("gpiolib: could not register GPIO bus type\n");
4249 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
4251 pr_err("gpiolib: failed to allocate char dev region\n");
4252 bus_unregister(&gpio_bus_type);
4254 gpiolib_initialized = true;
4255 gpiochip_setup_devs();
4259 core_initcall(gpiolib_dev_init);
4261 #ifdef CONFIG_DEBUG_FS
4263 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4266 struct gpio_chip *chip = gdev->chip;
4267 unsigned gpio = gdev->base;
4268 struct gpio_desc *gdesc = &gdev->descs[0];
4272 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4273 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4275 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4281 gpiod_get_direction(gdesc);
4282 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4283 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4284 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
4285 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4286 is_out ? "out" : "in ",
4287 chip->get ? (chip->get(chip, i) ? "hi" : "lo") : "? ",
4288 is_irq ? "IRQ" : " ");
4289 seq_printf(s, "\n");
4293 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4295 unsigned long flags;
4296 struct gpio_device *gdev = NULL;
4297 loff_t index = *pos;
4301 spin_lock_irqsave(&gpio_lock, flags);
4302 list_for_each_entry(gdev, &gpio_devices, list)
4304 spin_unlock_irqrestore(&gpio_lock, flags);
4307 spin_unlock_irqrestore(&gpio_lock, flags);
4312 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4314 unsigned long flags;
4315 struct gpio_device *gdev = v;
4318 spin_lock_irqsave(&gpio_lock, flags);
4319 if (list_is_last(&gdev->list, &gpio_devices))
4322 ret = list_entry(gdev->list.next, struct gpio_device, list);
4323 spin_unlock_irqrestore(&gpio_lock, flags);
4331 static void gpiolib_seq_stop(struct seq_file *s, void *v)
4335 static int gpiolib_seq_show(struct seq_file *s, void *v)
4337 struct gpio_device *gdev = v;
4338 struct gpio_chip *chip = gdev->chip;
4339 struct device *parent;
4342 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4343 dev_name(&gdev->dev));
4347 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4348 dev_name(&gdev->dev),
4349 gdev->base, gdev->base + gdev->ngpio - 1);
4350 parent = chip->parent;
4352 seq_printf(s, ", parent: %s/%s",
4353 parent->bus ? parent->bus->name : "no-bus",
4356 seq_printf(s, ", %s", chip->label);
4357 if (chip->can_sleep)
4358 seq_printf(s, ", can sleep");
4359 seq_printf(s, ":\n");
4362 chip->dbg_show(s, chip);
4364 gpiolib_dbg_show(s, gdev);
4369 static const struct seq_operations gpiolib_seq_ops = {
4370 .start = gpiolib_seq_start,
4371 .next = gpiolib_seq_next,
4372 .stop = gpiolib_seq_stop,
4373 .show = gpiolib_seq_show,
4376 static int gpiolib_open(struct inode *inode, struct file *file)
4378 return seq_open(file, &gpiolib_seq_ops);
4381 static const struct file_operations gpiolib_operations = {
4382 .owner = THIS_MODULE,
4383 .open = gpiolib_open,
4385 .llseek = seq_lseek,
4386 .release = seq_release,
4389 static int __init gpiolib_debugfs_init(void)
4391 /* /sys/kernel/debug/gpio */
4392 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
4393 NULL, NULL, &gpiolib_operations);
4396 subsys_initcall(gpiolib_debugfs_init);
4398 #endif /* DEBUG_FS */