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 /* NOTE: It's ok to read values of output lines. */
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;
1266 chip->of_node = gdev->dev.of_node;
1269 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1274 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1275 device_initialize(&gdev->dev);
1276 dev_set_drvdata(&gdev->dev, gdev);
1277 if (chip->parent && chip->parent->driver)
1278 gdev->owner = chip->parent->driver->owner;
1279 else if (chip->owner)
1280 /* TODO: remove chip->owner */
1281 gdev->owner = chip->owner;
1283 gdev->owner = THIS_MODULE;
1285 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1291 if (chip->ngpio == 0) {
1292 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1294 goto err_free_descs;
1297 if (chip->ngpio > FASTPATH_NGPIO)
1298 chip_warn(chip, "line cnt %u is greater than fast path cnt %u\n",
1299 chip->ngpio, FASTPATH_NGPIO);
1301 gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
1304 goto err_free_descs;
1307 gdev->ngpio = chip->ngpio;
1310 spin_lock_irqsave(&gpio_lock, flags);
1313 * TODO: this allocates a Linux GPIO number base in the global
1314 * GPIO numberspace for this chip. In the long run we want to
1315 * get *rid* of this numberspace and use only descriptors, but
1316 * it may be a pipe dream. It will not happen before we get rid
1317 * of the sysfs interface anyways.
1320 base = gpiochip_find_base(chip->ngpio);
1323 spin_unlock_irqrestore(&gpio_lock, flags);
1324 goto err_free_label;
1327 * TODO: it should not be necessary to reflect the assigned
1328 * base outside of the GPIO subsystem. Go over drivers and
1329 * see if anyone makes use of this, else drop this and assign
1336 status = gpiodev_add_to_list(gdev);
1338 spin_unlock_irqrestore(&gpio_lock, flags);
1339 goto err_free_label;
1342 spin_unlock_irqrestore(&gpio_lock, flags);
1344 for (i = 0; i < chip->ngpio; i++) {
1345 struct gpio_desc *desc = &gdev->descs[i];
1349 /* REVISIT: most hardware initializes GPIOs as inputs (often
1350 * with pullups enabled) so power usage is minimized. Linux
1351 * code should set the gpio direction first thing; but until
1352 * it does, and in case chip->get_direction is not set, we may
1353 * expose the wrong direction in sysfs.
1355 desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
1358 #ifdef CONFIG_PINCTRL
1359 INIT_LIST_HEAD(&gdev->pin_ranges);
1362 status = gpiochip_set_desc_names(chip);
1364 goto err_remove_from_list;
1366 status = gpiochip_irqchip_init_valid_mask(chip);
1368 goto err_remove_from_list;
1370 status = gpiochip_init_valid_mask(chip);
1372 goto err_remove_irqchip_mask;
1374 status = gpiochip_add_irqchip(chip, lock_key, request_key);
1376 goto err_remove_chip;
1378 status = of_gpiochip_add(chip);
1380 goto err_remove_chip;
1382 acpi_gpiochip_add(chip);
1384 machine_gpiochip_add(chip);
1387 * By first adding the chardev, and then adding the device,
1388 * we get a device node entry in sysfs under
1389 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1390 * coldplug of device nodes and other udev business.
1391 * We can do this only if gpiolib has been initialized.
1392 * Otherwise, defer until later.
1394 if (gpiolib_initialized) {
1395 status = gpiochip_setup_dev(gdev);
1397 goto err_remove_chip;
1402 acpi_gpiochip_remove(chip);
1403 gpiochip_free_hogs(chip);
1404 of_gpiochip_remove(chip);
1405 gpiochip_free_valid_mask(chip);
1406 err_remove_irqchip_mask:
1407 gpiochip_irqchip_free_valid_mask(chip);
1408 err_remove_from_list:
1409 spin_lock_irqsave(&gpio_lock, flags);
1410 list_del(&gdev->list);
1411 spin_unlock_irqrestore(&gpio_lock, flags);
1413 kfree_const(gdev->label);
1417 ida_simple_remove(&gpio_ida, gdev->id);
1418 /* failures here can mean systems won't boot... */
1419 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1420 gdev->base, gdev->base + gdev->ngpio - 1,
1421 chip->label ? : "generic", status);
1425 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1428 * gpiochip_get_data() - get per-subdriver data for the chip
1432 * The per-subdriver data for the chip.
1434 void *gpiochip_get_data(struct gpio_chip *chip)
1436 return chip->gpiodev->data;
1438 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1441 * gpiochip_remove() - unregister a gpio_chip
1442 * @chip: the chip to unregister
1444 * A gpio_chip with any GPIOs still requested may not be removed.
1446 void gpiochip_remove(struct gpio_chip *chip)
1448 struct gpio_device *gdev = chip->gpiodev;
1449 struct gpio_desc *desc;
1450 unsigned long flags;
1452 bool requested = false;
1454 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1455 gpiochip_sysfs_unregister(gdev);
1456 gpiochip_free_hogs(chip);
1457 /* Numb the device, cancelling all outstanding operations */
1459 gpiochip_irqchip_remove(chip);
1460 acpi_gpiochip_remove(chip);
1461 gpiochip_remove_pin_ranges(chip);
1462 of_gpiochip_remove(chip);
1463 gpiochip_free_valid_mask(chip);
1465 * We accept no more calls into the driver from this point, so
1466 * NULL the driver data pointer
1470 spin_lock_irqsave(&gpio_lock, flags);
1471 for (i = 0; i < gdev->ngpio; i++) {
1472 desc = &gdev->descs[i];
1473 if (test_bit(FLAG_REQUESTED, &desc->flags))
1476 spin_unlock_irqrestore(&gpio_lock, flags);
1479 dev_crit(&gdev->dev,
1480 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1483 * The gpiochip side puts its use of the device to rest here:
1484 * if there are no userspace clients, the chardev and device will
1485 * be removed, else it will be dangling until the last user is
1488 cdev_device_del(&gdev->chrdev, &gdev->dev);
1489 put_device(&gdev->dev);
1491 EXPORT_SYMBOL_GPL(gpiochip_remove);
1493 static void devm_gpio_chip_release(struct device *dev, void *res)
1495 struct gpio_chip *chip = *(struct gpio_chip **)res;
1497 gpiochip_remove(chip);
1500 static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
1503 struct gpio_chip **r = res;
1514 * devm_gpiochip_add_data() - Resource manager gpiochip_add_data()
1515 * @dev: the device pointer on which irq_chip belongs to.
1516 * @chip: the chip to register, with chip->base initialized
1517 * @data: driver-private data associated with this chip
1519 * Context: potentially before irqs will work
1521 * The gpio chip automatically be released when the device is unbound.
1524 * A negative errno if the chip can't be registered, such as because the
1525 * chip->base is invalid or already associated with a different chip.
1526 * Otherwise it returns zero as a success code.
1528 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1531 struct gpio_chip **ptr;
1534 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1539 ret = gpiochip_add_data(chip, data);
1546 devres_add(dev, ptr);
1550 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1553 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1554 * @dev: device for which which resource was allocated
1555 * @chip: the chip to remove
1557 * A gpio_chip with any GPIOs still requested may not be removed.
1559 void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
1563 ret = devres_release(dev, devm_gpio_chip_release,
1564 devm_gpio_chip_match, chip);
1567 EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
1570 * gpiochip_find() - iterator for locating a specific gpio_chip
1571 * @data: data to pass to match function
1572 * @match: Callback function to check gpio_chip
1574 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1575 * determined by a user supplied @match callback. The callback should return
1576 * 0 if the device doesn't match and non-zero if it does. If the callback is
1577 * non-zero, this function will return to the caller and not iterate over any
1580 struct gpio_chip *gpiochip_find(void *data,
1581 int (*match)(struct gpio_chip *chip,
1584 struct gpio_device *gdev;
1585 struct gpio_chip *chip = NULL;
1586 unsigned long flags;
1588 spin_lock_irqsave(&gpio_lock, flags);
1589 list_for_each_entry(gdev, &gpio_devices, list)
1590 if (gdev->chip && match(gdev->chip, data)) {
1595 spin_unlock_irqrestore(&gpio_lock, flags);
1599 EXPORT_SYMBOL_GPL(gpiochip_find);
1601 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1603 const char *name = data;
1605 return !strcmp(chip->label, name);
1608 static struct gpio_chip *find_chip_by_name(const char *name)
1610 return gpiochip_find((void *)name, gpiochip_match_name);
1613 #ifdef CONFIG_GPIOLIB_IRQCHIP
1616 * The following is irqchip helper code for gpiochips.
1619 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1621 if (!gpiochip->irq.need_valid_mask)
1624 gpiochip->irq.valid_mask = gpiochip_allocate_mask(gpiochip);
1625 if (!gpiochip->irq.valid_mask)
1631 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1633 kfree(gpiochip->irq.valid_mask);
1634 gpiochip->irq.valid_mask = NULL;
1637 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1638 unsigned int offset)
1640 if (!gpiochip_line_is_valid(gpiochip, offset))
1642 /* No mask means all valid */
1643 if (likely(!gpiochip->irq.valid_mask))
1645 return test_bit(offset, gpiochip->irq.valid_mask);
1647 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1650 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1651 * @gpiochip: the gpiochip to set the irqchip chain to
1652 * @irqchip: the irqchip to chain to the gpiochip
1653 * @parent_irq: the irq number corresponding to the parent IRQ for this
1655 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1656 * coming out of the gpiochip. If the interrupt is nested rather than
1657 * cascaded, pass NULL in this handler argument
1659 static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
1660 struct irq_chip *irqchip,
1661 unsigned int parent_irq,
1662 irq_flow_handler_t parent_handler)
1664 unsigned int offset;
1666 if (!gpiochip->irq.domain) {
1667 chip_err(gpiochip, "called %s before setting up irqchip\n",
1672 if (parent_handler) {
1673 if (gpiochip->can_sleep) {
1675 "you cannot have chained interrupts on a chip that may sleep\n");
1679 * The parent irqchip is already using the chip_data for this
1680 * irqchip, so our callbacks simply use the handler_data.
1682 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1685 gpiochip->irq.parent_irq = parent_irq;
1686 gpiochip->irq.parents = &gpiochip->irq.parent_irq;
1687 gpiochip->irq.num_parents = 1;
1690 /* Set the parent IRQ for all affected IRQs */
1691 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1692 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1694 irq_set_parent(irq_find_mapping(gpiochip->irq.domain, offset),
1700 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1701 * @gpiochip: the gpiochip to set the irqchip chain to
1702 * @irqchip: the irqchip to chain to the gpiochip
1703 * @parent_irq: the irq number corresponding to the parent IRQ for this
1705 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1706 * coming out of the gpiochip. If the interrupt is nested rather than
1707 * cascaded, pass NULL in this handler argument
1709 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1710 struct irq_chip *irqchip,
1711 unsigned int parent_irq,
1712 irq_flow_handler_t parent_handler)
1714 if (gpiochip->irq.threaded) {
1715 chip_err(gpiochip, "tried to chain a threaded gpiochip\n");
1719 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1722 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1725 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1726 * @gpiochip: the gpiochip to set the irqchip nested handler to
1727 * @irqchip: the irqchip to nest to the gpiochip
1728 * @parent_irq: the irq number corresponding to the parent IRQ for this
1731 void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1732 struct irq_chip *irqchip,
1733 unsigned int parent_irq)
1735 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1738 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1741 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1742 * @d: the irqdomain used by this irqchip
1743 * @irq: the global irq number used by this GPIO irqchip irq
1744 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1746 * This function will set up the mapping for a certain IRQ line on a
1747 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1748 * stored inside the gpiochip.
1750 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1751 irq_hw_number_t hwirq)
1753 struct gpio_chip *chip = d->host_data;
1756 if (!gpiochip_irqchip_irq_valid(chip, hwirq))
1759 irq_set_chip_data(irq, chip);
1761 * This lock class tells lockdep that GPIO irqs are in a different
1762 * category than their parents, so it won't report false recursion.
1764 irq_set_lockdep_class(irq, chip->irq.lock_key, chip->irq.request_key);
1765 irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
1766 /* Chips that use nested thread handlers have them marked */
1767 if (chip->irq.threaded)
1768 irq_set_nested_thread(irq, 1);
1769 irq_set_noprobe(irq);
1771 if (chip->irq.num_parents == 1)
1772 err = irq_set_parent(irq, chip->irq.parents[0]);
1773 else if (chip->irq.map)
1774 err = irq_set_parent(irq, chip->irq.map[hwirq]);
1780 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1781 * is passed as default type.
1783 if (chip->irq.default_type != IRQ_TYPE_NONE)
1784 irq_set_irq_type(irq, chip->irq.default_type);
1788 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1790 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1792 struct gpio_chip *chip = d->host_data;
1794 if (chip->irq.threaded)
1795 irq_set_nested_thread(irq, 0);
1796 irq_set_chip_and_handler(irq, NULL, NULL);
1797 irq_set_chip_data(irq, NULL);
1799 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1801 static const struct irq_domain_ops gpiochip_domain_ops = {
1802 .map = gpiochip_irq_map,
1803 .unmap = gpiochip_irq_unmap,
1804 /* Virtually all GPIO irqchips are twocell:ed */
1805 .xlate = irq_domain_xlate_twocell,
1808 static int gpiochip_irq_reqres(struct irq_data *d)
1810 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1813 if (!try_module_get(chip->gpiodev->owner))
1816 ret = gpiochip_lock_as_irq(chip, d->hwirq);
1819 "unable to lock HW IRQ %lu for IRQ\n",
1821 module_put(chip->gpiodev->owner);
1827 static void gpiochip_irq_relres(struct irq_data *d)
1829 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1831 gpiochip_unlock_as_irq(chip, d->hwirq);
1832 module_put(chip->gpiodev->owner);
1835 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1837 if (!gpiochip_irqchip_irq_valid(chip, offset))
1840 return irq_create_mapping(chip->irq.domain, offset);
1844 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1845 * @gpiochip: the GPIO chip to add the IRQ chip to
1846 * @lock_key: lockdep class for IRQ lock
1847 * @request_key: lockdep class for IRQ request
1849 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
1850 struct lock_class_key *lock_key,
1851 struct lock_class_key *request_key)
1853 struct irq_chip *irqchip = gpiochip->irq.chip;
1854 const struct irq_domain_ops *ops;
1855 struct device_node *np;
1862 if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {
1863 chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n");
1867 np = gpiochip->gpiodev->dev.of_node;
1868 type = gpiochip->irq.default_type;
1871 * Specifying a default trigger is a terrible idea if DT or ACPI is
1872 * used to configure the interrupts, as you may end up with
1873 * conflicting triggers. Tell the user, and reset to NONE.
1875 if (WARN(np && type != IRQ_TYPE_NONE,
1876 "%s: Ignoring %u default trigger\n", np->full_name, type))
1877 type = IRQ_TYPE_NONE;
1879 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1880 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1881 "Ignoring %u default trigger\n", type);
1882 type = IRQ_TYPE_NONE;
1885 gpiochip->to_irq = gpiochip_to_irq;
1886 gpiochip->irq.default_type = type;
1887 gpiochip->irq.lock_key = lock_key;
1888 gpiochip->irq.request_key = request_key;
1890 if (gpiochip->irq.domain_ops)
1891 ops = gpiochip->irq.domain_ops;
1893 ops = &gpiochip_domain_ops;
1895 gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
1896 gpiochip->irq.first,
1898 if (!gpiochip->irq.domain)
1902 * It is possible for a driver to override this, but only if the
1903 * alternative functions are both implemented.
1905 if (!irqchip->irq_request_resources &&
1906 !irqchip->irq_release_resources) {
1907 irqchip->irq_request_resources = gpiochip_irq_reqres;
1908 irqchip->irq_release_resources = gpiochip_irq_relres;
1911 if (gpiochip->irq.parent_handler) {
1912 void *data = gpiochip->irq.parent_handler_data ?: gpiochip;
1914 for (i = 0; i < gpiochip->irq.num_parents; i++) {
1916 * The parent IRQ chip is already using the chip_data
1917 * for this IRQ chip, so our callbacks simply use the
1920 irq_set_chained_handler_and_data(gpiochip->irq.parents[i],
1921 gpiochip->irq.parent_handler,
1926 acpi_gpiochip_request_interrupts(gpiochip);
1932 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1933 * @gpiochip: the gpiochip to remove the irqchip from
1935 * This is called only from gpiochip_remove()
1937 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1939 unsigned int offset;
1941 acpi_gpiochip_free_interrupts(gpiochip);
1943 if (gpiochip->irq.chip && gpiochip->irq.parent_handler) {
1944 struct gpio_irq_chip *irq = &gpiochip->irq;
1947 for (i = 0; i < irq->num_parents; i++)
1948 irq_set_chained_handler_and_data(irq->parents[i],
1952 /* Remove all IRQ mappings and delete the domain */
1953 if (gpiochip->irq.domain) {
1956 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1957 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1960 irq = irq_find_mapping(gpiochip->irq.domain, offset);
1961 irq_dispose_mapping(irq);
1964 irq_domain_remove(gpiochip->irq.domain);
1967 if (gpiochip->irq.chip) {
1968 gpiochip->irq.chip->irq_request_resources = NULL;
1969 gpiochip->irq.chip->irq_release_resources = NULL;
1970 gpiochip->irq.chip = NULL;
1973 gpiochip_irqchip_free_valid_mask(gpiochip);
1977 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
1978 * @gpiochip: the gpiochip to add the irqchip to
1979 * @irqchip: the irqchip to add to the gpiochip
1980 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1981 * allocate gpiochip irqs from
1982 * @handler: the irq handler to use (often a predefined irq core function)
1983 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1984 * to have the core avoid setting up any default type in the hardware.
1985 * @threaded: whether this irqchip uses a nested thread handler
1986 * @lock_key: lockdep class for IRQ lock
1987 * @request_key: lockdep class for IRQ request
1989 * This function closely associates a certain irqchip with a certain
1990 * gpiochip, providing an irq domain to translate the local IRQs to
1991 * global irqs in the gpiolib core, and making sure that the gpiochip
1992 * is passed as chip data to all related functions. Driver callbacks
1993 * need to use gpiochip_get_data() to get their local state containers back
1994 * from the gpiochip passed as chip data. An irqdomain will be stored
1995 * in the gpiochip that shall be used by the driver to handle IRQ number
1996 * translation. The gpiochip will need to be initialized and registered
1997 * before calling this function.
1999 * This function will handle two cell:ed simple IRQs and assumes all
2000 * the pins on the gpiochip can generate a unique IRQ. Everything else
2001 * need to be open coded.
2003 int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
2004 struct irq_chip *irqchip,
2005 unsigned int first_irq,
2006 irq_flow_handler_t handler,
2009 struct lock_class_key *lock_key,
2010 struct lock_class_key *request_key)
2012 struct device_node *of_node;
2014 if (!gpiochip || !irqchip)
2017 if (!gpiochip->parent) {
2018 pr_err("missing gpiochip .dev parent pointer\n");
2021 gpiochip->irq.threaded = threaded;
2022 of_node = gpiochip->parent->of_node;
2023 #ifdef CONFIG_OF_GPIO
2025 * If the gpiochip has an assigned OF node this takes precedence
2026 * FIXME: get rid of this and use gpiochip->parent->of_node
2029 if (gpiochip->of_node)
2030 of_node = gpiochip->of_node;
2033 * Specifying a default trigger is a terrible idea if DT or ACPI is
2034 * used to configure the interrupts, as you may end-up with
2035 * conflicting triggers. Tell the user, and reset to NONE.
2037 if (WARN(of_node && type != IRQ_TYPE_NONE,
2038 "%pOF: Ignoring %d default trigger\n", of_node, type))
2039 type = IRQ_TYPE_NONE;
2040 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
2041 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
2042 "Ignoring %d default trigger\n", type);
2043 type = IRQ_TYPE_NONE;
2046 gpiochip->irq.chip = irqchip;
2047 gpiochip->irq.handler = handler;
2048 gpiochip->irq.default_type = type;
2049 gpiochip->to_irq = gpiochip_to_irq;
2050 gpiochip->irq.lock_key = lock_key;
2051 gpiochip->irq.request_key = request_key;
2052 gpiochip->irq.domain = irq_domain_add_simple(of_node,
2053 gpiochip->ngpio, first_irq,
2054 &gpiochip_domain_ops, gpiochip);
2055 if (!gpiochip->irq.domain) {
2056 gpiochip->irq.chip = NULL;
2061 * It is possible for a driver to override this, but only if the
2062 * alternative functions are both implemented.
2064 if (!irqchip->irq_request_resources &&
2065 !irqchip->irq_release_resources) {
2066 irqchip->irq_request_resources = gpiochip_irq_reqres;
2067 irqchip->irq_release_resources = gpiochip_irq_relres;
2070 acpi_gpiochip_request_interrupts(gpiochip);
2074 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
2076 #else /* CONFIG_GPIOLIB_IRQCHIP */
2078 static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
2079 struct lock_class_key *lock_key,
2080 struct lock_class_key *request_key)
2085 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
2086 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
2090 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
2093 #endif /* CONFIG_GPIOLIB_IRQCHIP */
2096 * gpiochip_generic_request() - request the gpio function for a pin
2097 * @chip: the gpiochip owning the GPIO
2098 * @offset: the offset of the GPIO to request for GPIO function
2100 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
2102 return pinctrl_gpio_request(chip->gpiodev->base + offset);
2104 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2107 * gpiochip_generic_free() - free the gpio function from a pin
2108 * @chip: the gpiochip to request the gpio function for
2109 * @offset: the offset of the GPIO to free from GPIO function
2111 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
2113 pinctrl_gpio_free(chip->gpiodev->base + offset);
2115 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2118 * gpiochip_generic_config() - apply configuration for a pin
2119 * @chip: the gpiochip owning the GPIO
2120 * @offset: the offset of the GPIO to apply the configuration
2121 * @config: the configuration to be applied
2123 int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
2124 unsigned long config)
2126 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
2128 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2130 #ifdef CONFIG_PINCTRL
2133 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2134 * @chip: the gpiochip to add the range for
2135 * @pctldev: the pin controller to map to
2136 * @gpio_offset: the start offset in the current gpio_chip number space
2137 * @pin_group: name of the pin group inside the pin controller
2139 * Calling this function directly from a DeviceTree-supported
2140 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2141 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2142 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2144 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
2145 struct pinctrl_dev *pctldev,
2146 unsigned int gpio_offset, const char *pin_group)
2148 struct gpio_pin_range *pin_range;
2149 struct gpio_device *gdev = chip->gpiodev;
2152 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2154 chip_err(chip, "failed to allocate pin ranges\n");
2158 /* Use local offset as range ID */
2159 pin_range->range.id = gpio_offset;
2160 pin_range->range.gc = chip;
2161 pin_range->range.name = chip->label;
2162 pin_range->range.base = gdev->base + gpio_offset;
2163 pin_range->pctldev = pctldev;
2165 ret = pinctrl_get_group_pins(pctldev, pin_group,
2166 &pin_range->range.pins,
2167 &pin_range->range.npins);
2173 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2175 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2176 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2177 pinctrl_dev_get_devname(pctldev), pin_group);
2179 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2183 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2186 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2187 * @chip: the gpiochip to add the range for
2188 * @pinctl_name: the dev_name() of the pin controller to map to
2189 * @gpio_offset: the start offset in the current gpio_chip number space
2190 * @pin_offset: the start offset in the pin controller number space
2191 * @npins: the number of pins from the offset of each pin space (GPIO and
2192 * pin controller) to accumulate in this range
2195 * 0 on success, or a negative error-code on failure.
2197 * Calling this function directly from a DeviceTree-supported
2198 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2199 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2200 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2202 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
2203 unsigned int gpio_offset, unsigned int pin_offset,
2206 struct gpio_pin_range *pin_range;
2207 struct gpio_device *gdev = chip->gpiodev;
2210 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2212 chip_err(chip, "failed to allocate pin ranges\n");
2216 /* Use local offset as range ID */
2217 pin_range->range.id = gpio_offset;
2218 pin_range->range.gc = chip;
2219 pin_range->range.name = chip->label;
2220 pin_range->range.base = gdev->base + gpio_offset;
2221 pin_range->range.pin_base = pin_offset;
2222 pin_range->range.npins = npins;
2223 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2225 if (IS_ERR(pin_range->pctldev)) {
2226 ret = PTR_ERR(pin_range->pctldev);
2227 chip_err(chip, "could not create pin range\n");
2231 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2232 gpio_offset, gpio_offset + npins - 1,
2234 pin_offset, pin_offset + npins - 1);
2236 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2240 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2243 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2244 * @chip: the chip to remove all the mappings for
2246 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
2248 struct gpio_pin_range *pin_range, *tmp;
2249 struct gpio_device *gdev = chip->gpiodev;
2251 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2252 list_del(&pin_range->node);
2253 pinctrl_remove_gpio_range(pin_range->pctldev,
2258 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2260 #endif /* CONFIG_PINCTRL */
2262 /* These "optional" allocation calls help prevent drivers from stomping
2263 * on each other, and help provide better diagnostics in debugfs.
2264 * They're called even less than the "set direction" calls.
2266 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2268 struct gpio_chip *chip = desc->gdev->chip;
2270 unsigned long flags;
2273 spin_lock_irqsave(&gpio_lock, flags);
2275 /* NOTE: gpio_request() can be called in early boot,
2276 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2279 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2280 desc_set_label(desc, label ? : "?");
2287 if (chip->request) {
2288 /* chip->request may sleep */
2289 spin_unlock_irqrestore(&gpio_lock, flags);
2290 offset = gpio_chip_hwgpio(desc);
2291 if (gpiochip_line_is_valid(chip, offset))
2292 status = chip->request(chip, offset);
2295 spin_lock_irqsave(&gpio_lock, flags);
2298 desc_set_label(desc, NULL);
2299 clear_bit(FLAG_REQUESTED, &desc->flags);
2303 if (chip->get_direction) {
2304 /* chip->get_direction may sleep */
2305 spin_unlock_irqrestore(&gpio_lock, flags);
2306 gpiod_get_direction(desc);
2307 spin_lock_irqsave(&gpio_lock, flags);
2310 spin_unlock_irqrestore(&gpio_lock, flags);
2315 * This descriptor validation needs to be inserted verbatim into each
2316 * function taking a descriptor, so we need to use a preprocessor
2317 * macro to avoid endless duplication. If the desc is NULL it is an
2318 * optional GPIO and calls should just bail out.
2320 static int validate_desc(const struct gpio_desc *desc, const char *func)
2325 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2326 return PTR_ERR(desc);
2329 pr_warn("%s: invalid GPIO (no device)\n", func);
2332 if (!desc->gdev->chip) {
2333 dev_warn(&desc->gdev->dev,
2334 "%s: backing chip is gone\n", func);
2340 #define VALIDATE_DESC(desc) do { \
2341 int __valid = validate_desc(desc, __func__); \
2346 #define VALIDATE_DESC_VOID(desc) do { \
2347 int __valid = validate_desc(desc, __func__); \
2352 int gpiod_request(struct gpio_desc *desc, const char *label)
2354 int status = -EPROBE_DEFER;
2355 struct gpio_device *gdev;
2357 VALIDATE_DESC(desc);
2360 if (try_module_get(gdev->owner)) {
2361 status = gpiod_request_commit(desc, label);
2363 module_put(gdev->owner);
2365 get_device(&gdev->dev);
2369 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2374 static bool gpiod_free_commit(struct gpio_desc *desc)
2377 unsigned long flags;
2378 struct gpio_chip *chip;
2382 gpiod_unexport(desc);
2384 spin_lock_irqsave(&gpio_lock, flags);
2386 chip = desc->gdev->chip;
2387 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2389 spin_unlock_irqrestore(&gpio_lock, flags);
2390 might_sleep_if(chip->can_sleep);
2391 chip->free(chip, gpio_chip_hwgpio(desc));
2392 spin_lock_irqsave(&gpio_lock, flags);
2394 desc_set_label(desc, NULL);
2395 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2396 clear_bit(FLAG_REQUESTED, &desc->flags);
2397 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2398 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2399 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2403 spin_unlock_irqrestore(&gpio_lock, flags);
2407 void gpiod_free(struct gpio_desc *desc)
2409 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2410 module_put(desc->gdev->owner);
2411 put_device(&desc->gdev->dev);
2413 WARN_ON(extra_checks);
2418 * gpiochip_is_requested - return string iff signal was requested
2419 * @chip: controller managing the signal
2420 * @offset: of signal within controller's 0..(ngpio - 1) range
2422 * Returns NULL if the GPIO is not currently requested, else a string.
2423 * The string returned is the label passed to gpio_request(); if none has been
2424 * passed it is a meaningless, non-NULL constant.
2426 * This function is for use by GPIO controller drivers. The label can
2427 * help with diagnostics, and knowing that the signal is used as a GPIO
2428 * can help avoid accidentally multiplexing it to another controller.
2430 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2432 struct gpio_desc *desc;
2434 if (offset >= chip->ngpio)
2437 desc = &chip->gpiodev->descs[offset];
2439 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2443 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2446 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2448 * @hwnum: hardware number of the GPIO for which to request the descriptor
2449 * @label: label for the GPIO
2451 * Function allows GPIO chip drivers to request and use their own GPIO
2452 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2453 * function will not increase reference count of the GPIO chip module. This
2454 * allows the GPIO chip module to be unloaded as needed (we assume that the
2455 * GPIO chip driver handles freeing the GPIOs it has requested).
2458 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2461 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2464 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2468 chip_err(chip, "failed to get GPIO descriptor\n");
2472 err = gpiod_request_commit(desc, label);
2474 return ERR_PTR(err);
2478 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2481 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2482 * @desc: GPIO descriptor to free
2484 * Function frees the given GPIO requested previously with
2485 * gpiochip_request_own_desc().
2487 void gpiochip_free_own_desc(struct gpio_desc *desc)
2490 gpiod_free_commit(desc);
2492 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2495 * Drivers MUST set GPIO direction before making get/set calls. In
2496 * some cases this is done in early boot, before IRQs are enabled.
2498 * As a rule these aren't called more than once (except for drivers
2499 * using the open-drain emulation idiom) so these are natural places
2500 * to accumulate extra debugging checks. Note that we can't (yet)
2501 * rely on gpio_request() having been called beforehand.
2505 * gpiod_direction_input - set the GPIO direction to input
2506 * @desc: GPIO to set to input
2508 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2509 * be called safely on it.
2511 * Return 0 in case of success, else an error code.
2513 int gpiod_direction_input(struct gpio_desc *desc)
2515 struct gpio_chip *chip;
2516 int status = -EINVAL;
2518 VALIDATE_DESC(desc);
2519 chip = desc->gdev->chip;
2521 if (!chip->get || !chip->direction_input) {
2523 "%s: missing get() or direction_input() operations\n",
2528 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2530 clear_bit(FLAG_IS_OUT, &desc->flags);
2532 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2536 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2538 static int gpio_set_drive_single_ended(struct gpio_chip *gc, unsigned offset,
2539 enum pin_config_param mode)
2541 unsigned long config = { PIN_CONF_PACKED(mode, 0) };
2543 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2546 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2548 struct gpio_chip *gc = desc->gdev->chip;
2552 if (!gc->set || !gc->direction_output) {
2554 "%s: missing set() or direction_output() operations\n",
2559 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2561 set_bit(FLAG_IS_OUT, &desc->flags);
2562 trace_gpio_value(desc_to_gpio(desc), 0, val);
2563 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2568 * gpiod_direction_output_raw - set the GPIO direction to output
2569 * @desc: GPIO to set to output
2570 * @value: initial output value of the GPIO
2572 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2573 * be called safely on it. The initial value of the output must be specified
2574 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2576 * Return 0 in case of success, else an error code.
2578 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2580 VALIDATE_DESC(desc);
2581 return gpiod_direction_output_raw_commit(desc, value);
2583 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2586 * gpiod_direction_output - set the GPIO direction to output
2587 * @desc: GPIO to set to output
2588 * @value: initial output value of the GPIO
2590 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2591 * be called safely on it. The initial value of the output must be specified
2592 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2595 * Return 0 in case of success, else an error code.
2597 int gpiod_direction_output(struct gpio_desc *desc, int value)
2599 struct gpio_chip *gc;
2602 VALIDATE_DESC(desc);
2603 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2608 /* GPIOs used for IRQs shall not be set as output */
2609 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
2611 "%s: tried to set a GPIO tied to an IRQ as output\n",
2616 gc = desc->gdev->chip;
2617 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2618 /* First see if we can enable open drain in hardware */
2619 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2620 PIN_CONFIG_DRIVE_OPEN_DRAIN);
2622 goto set_output_value;
2623 /* Emulate open drain by not actively driving the line high */
2625 return gpiod_direction_input(desc);
2627 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2628 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2629 PIN_CONFIG_DRIVE_OPEN_SOURCE);
2631 goto set_output_value;
2632 /* Emulate open source by not actively driving the line low */
2634 return gpiod_direction_input(desc);
2636 gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2637 PIN_CONFIG_DRIVE_PUSH_PULL);
2641 return gpiod_direction_output_raw_commit(desc, value);
2643 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2646 * gpiod_set_debounce - sets @debounce time for a GPIO
2647 * @desc: descriptor of the GPIO for which to set debounce time
2648 * @debounce: debounce time in microseconds
2651 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2654 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2656 struct gpio_chip *chip;
2657 unsigned long config;
2659 VALIDATE_DESC(desc);
2660 chip = desc->gdev->chip;
2661 if (!chip->set || !chip->set_config) {
2663 "%s: missing set() or set_config() operations\n",
2668 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2669 return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
2671 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2674 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2675 * @desc: descriptor of the GPIO for which to configure persistence
2676 * @transitory: True to lose state on suspend or reset, false for persistence
2679 * 0 on success, otherwise a negative error code.
2681 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2683 struct gpio_chip *chip;
2684 unsigned long packed;
2688 VALIDATE_DESC(desc);
2690 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2691 * persistence state.
2694 set_bit(FLAG_TRANSITORY, &desc->flags);
2696 clear_bit(FLAG_TRANSITORY, &desc->flags);
2698 /* If the driver supports it, set the persistence state now */
2699 chip = desc->gdev->chip;
2700 if (!chip->set_config)
2703 packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
2705 gpio = gpio_chip_hwgpio(desc);
2706 rc = chip->set_config(chip, gpio, packed);
2707 if (rc == -ENOTSUPP) {
2708 dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
2715 EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2718 * gpiod_is_active_low - test whether a GPIO is active-low or not
2719 * @desc: the gpio descriptor to test
2721 * Returns 1 if the GPIO is active-low, 0 otherwise.
2723 int gpiod_is_active_low(const struct gpio_desc *desc)
2725 VALIDATE_DESC(desc);
2726 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2728 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2730 /* I/O calls are only valid after configuration completed; the relevant
2731 * "is this a valid GPIO" error checks should already have been done.
2733 * "Get" operations are often inlinable as reading a pin value register,
2734 * and masking the relevant bit in that register.
2736 * When "set" operations are inlinable, they involve writing that mask to
2737 * one register to set a low value, or a different register to set it high.
2738 * Otherwise locking is needed, so there may be little value to inlining.
2740 *------------------------------------------------------------------------
2742 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2743 * have requested the GPIO. That can include implicit requesting by
2744 * a direction setting call. Marking a gpio as requested locks its chip
2745 * in memory, guaranteeing that these table lookups need no more locking
2746 * and that gpiochip_remove() will fail.
2748 * REVISIT when debugging, consider adding some instrumentation to ensure
2749 * that the GPIO was actually requested.
2752 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2754 struct gpio_chip *chip;
2758 chip = desc->gdev->chip;
2759 offset = gpio_chip_hwgpio(desc);
2760 value = chip->get ? chip->get(chip, offset) : -EIO;
2761 value = value < 0 ? value : !!value;
2762 trace_gpio_value(desc_to_gpio(desc), 1, value);
2766 static int gpio_chip_get_multiple(struct gpio_chip *chip,
2767 unsigned long *mask, unsigned long *bits)
2769 if (chip->get_multiple) {
2770 return chip->get_multiple(chip, mask, bits);
2771 } else if (chip->get) {
2774 for_each_set_bit(i, mask, chip->ngpio) {
2775 value = chip->get(chip, i);
2778 __assign_bit(i, bits, value);
2785 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2786 unsigned int array_size,
2787 struct gpio_desc **desc_array,
2792 while (i < array_size) {
2793 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2794 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
2795 unsigned long *mask, *bits;
2798 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
2801 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
2803 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
2808 bits = mask + BITS_TO_LONGS(chip->ngpio);
2809 bitmap_zero(mask, chip->ngpio);
2812 WARN_ON(chip->can_sleep);
2814 /* collect all inputs belonging to the same chip */
2817 const struct gpio_desc *desc = desc_array[i];
2818 int hwgpio = gpio_chip_hwgpio(desc);
2820 __set_bit(hwgpio, mask);
2822 } while ((i < array_size) &&
2823 (desc_array[i]->gdev->chip == chip));
2825 ret = gpio_chip_get_multiple(chip, mask, bits);
2827 if (mask != fastpath)
2832 for (j = first; j < i; j++) {
2833 const struct gpio_desc *desc = desc_array[j];
2834 int hwgpio = gpio_chip_hwgpio(desc);
2835 int value = test_bit(hwgpio, bits);
2837 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2839 value_array[j] = value;
2840 trace_gpio_value(desc_to_gpio(desc), 1, value);
2843 if (mask != fastpath)
2850 * gpiod_get_raw_value() - return a gpio's raw value
2851 * @desc: gpio whose value will be returned
2853 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2854 * its ACTIVE_LOW status, or negative errno on failure.
2856 * This function should be called from contexts where we cannot sleep, and will
2857 * complain if the GPIO chip functions potentially sleep.
2859 int gpiod_get_raw_value(const struct gpio_desc *desc)
2861 VALIDATE_DESC(desc);
2862 /* Should be using gpio_get_value_cansleep() */
2863 WARN_ON(desc->gdev->chip->can_sleep);
2864 return gpiod_get_raw_value_commit(desc);
2866 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2869 * gpiod_get_value() - return a gpio's value
2870 * @desc: gpio whose value will be returned
2872 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2873 * account, or negative errno on failure.
2875 * This function should be called from contexts where we cannot sleep, and will
2876 * complain if the GPIO chip functions potentially sleep.
2878 int gpiod_get_value(const struct gpio_desc *desc)
2882 VALIDATE_DESC(desc);
2883 /* Should be using gpio_get_value_cansleep() */
2884 WARN_ON(desc->gdev->chip->can_sleep);
2886 value = gpiod_get_raw_value_commit(desc);
2890 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2895 EXPORT_SYMBOL_GPL(gpiod_get_value);
2898 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
2899 * @array_size: number of elements in the descriptor / value arrays
2900 * @desc_array: array of GPIO descriptors whose values will be read
2901 * @value_array: array to store the read values
2903 * Read the raw values of the GPIOs, i.e. the values of the physical lines
2904 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
2905 * else an error code.
2907 * This function should be called from contexts where we cannot sleep,
2908 * and it will complain if the GPIO chip functions potentially sleep.
2910 int gpiod_get_raw_array_value(unsigned int array_size,
2911 struct gpio_desc **desc_array, int *value_array)
2915 return gpiod_get_array_value_complex(true, false, array_size,
2916 desc_array, value_array);
2918 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
2921 * gpiod_get_array_value() - read values from an array of GPIOs
2922 * @array_size: number of elements in the descriptor / value arrays
2923 * @desc_array: array of GPIO descriptors whose values will be read
2924 * @value_array: array to store the read values
2926 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2927 * into account. Return 0 in case of success, else an error code.
2929 * This function should be called from contexts where we cannot sleep,
2930 * and it will complain if the GPIO chip functions potentially sleep.
2932 int gpiod_get_array_value(unsigned int array_size,
2933 struct gpio_desc **desc_array, int *value_array)
2937 return gpiod_get_array_value_complex(false, false, array_size,
2938 desc_array, value_array);
2940 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
2943 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
2944 * @desc: gpio descriptor whose state need to be set.
2945 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2947 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
2950 struct gpio_chip *chip = desc->gdev->chip;
2951 int offset = gpio_chip_hwgpio(desc);
2954 err = chip->direction_input(chip, offset);
2956 clear_bit(FLAG_IS_OUT, &desc->flags);
2958 err = chip->direction_output(chip, offset, 0);
2960 set_bit(FLAG_IS_OUT, &desc->flags);
2962 trace_gpio_direction(desc_to_gpio(desc), value, err);
2965 "%s: Error in set_value for open drain err %d\n",
2970 * _gpio_set_open_source_value() - Set the open source gpio's value.
2971 * @desc: gpio descriptor whose state need to be set.
2972 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2974 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
2977 struct gpio_chip *chip = desc->gdev->chip;
2978 int offset = gpio_chip_hwgpio(desc);
2981 err = chip->direction_output(chip, offset, 1);
2983 set_bit(FLAG_IS_OUT, &desc->flags);
2985 err = chip->direction_input(chip, offset);
2987 clear_bit(FLAG_IS_OUT, &desc->flags);
2989 trace_gpio_direction(desc_to_gpio(desc), !value, err);
2992 "%s: Error in set_value for open source err %d\n",
2996 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
2998 struct gpio_chip *chip;
3000 chip = desc->gdev->chip;
3001 trace_gpio_value(desc_to_gpio(desc), 0, value);
3002 chip->set(chip, gpio_chip_hwgpio(desc), value);
3006 * set multiple outputs on the same chip;
3007 * use the chip's set_multiple function if available;
3008 * otherwise set the outputs sequentially;
3009 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3010 * defines which outputs are to be changed
3011 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3012 * defines the values the outputs specified by mask are to be set to
3014 static void gpio_chip_set_multiple(struct gpio_chip *chip,
3015 unsigned long *mask, unsigned long *bits)
3017 if (chip->set_multiple) {
3018 chip->set_multiple(chip, mask, bits);
3022 /* set outputs if the corresponding mask bit is set */
3023 for_each_set_bit(i, mask, chip->ngpio)
3024 chip->set(chip, i, test_bit(i, bits));
3028 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3029 unsigned int array_size,
3030 struct gpio_desc **desc_array,
3035 while (i < array_size) {
3036 struct gpio_chip *chip = desc_array[i]->gdev->chip;
3037 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
3038 unsigned long *mask, *bits;
3041 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
3044 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
3046 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
3051 bits = mask + BITS_TO_LONGS(chip->ngpio);
3052 bitmap_zero(mask, chip->ngpio);
3055 WARN_ON(chip->can_sleep);
3058 struct gpio_desc *desc = desc_array[i];
3059 int hwgpio = gpio_chip_hwgpio(desc);
3060 int value = value_array[i];
3062 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3064 trace_gpio_value(desc_to_gpio(desc), 0, value);
3066 * collect all normal outputs belonging to the same chip
3067 * open drain and open source outputs are set individually
3069 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3070 gpio_set_open_drain_value_commit(desc, value);
3071 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3072 gpio_set_open_source_value_commit(desc, value);
3074 __set_bit(hwgpio, mask);
3076 __set_bit(hwgpio, bits);
3078 __clear_bit(hwgpio, bits);
3082 } while ((i < array_size) &&
3083 (desc_array[i]->gdev->chip == chip));
3084 /* push collected bits to outputs */
3086 gpio_chip_set_multiple(chip, mask, bits);
3088 if (mask != fastpath)
3095 * gpiod_set_raw_value() - assign a gpio's raw value
3096 * @desc: gpio whose value will be assigned
3097 * @value: value to assign
3099 * Set the raw value of the GPIO, i.e. the value of its physical line without
3100 * regard for its ACTIVE_LOW status.
3102 * This function should be called from contexts where we cannot sleep, and will
3103 * complain if the GPIO chip functions potentially sleep.
3105 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3107 VALIDATE_DESC_VOID(desc);
3108 /* Should be using gpiod_set_value_cansleep() */
3109 WARN_ON(desc->gdev->chip->can_sleep);
3110 gpiod_set_raw_value_commit(desc, value);
3112 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3115 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3116 * @desc: the descriptor to set the value on
3117 * @value: value to set
3119 * This sets the value of a GPIO line backing a descriptor, applying
3120 * different semantic quirks like active low and open drain/source
3123 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3125 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3127 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3128 gpio_set_open_drain_value_commit(desc, value);
3129 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3130 gpio_set_open_source_value_commit(desc, value);
3132 gpiod_set_raw_value_commit(desc, value);
3136 * gpiod_set_value() - assign a gpio's value
3137 * @desc: gpio whose value will be assigned
3138 * @value: value to assign
3140 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3141 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3143 * This function should be called from contexts where we cannot sleep, and will
3144 * complain if the GPIO chip functions potentially sleep.
3146 void gpiod_set_value(struct gpio_desc *desc, int value)
3148 VALIDATE_DESC_VOID(desc);
3149 WARN_ON(desc->gdev->chip->can_sleep);
3150 gpiod_set_value_nocheck(desc, value);
3152 EXPORT_SYMBOL_GPL(gpiod_set_value);
3155 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3156 * @array_size: number of elements in the descriptor / value arrays
3157 * @desc_array: array of GPIO descriptors whose values will be assigned
3158 * @value_array: array of values to assign
3160 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3161 * without regard for their ACTIVE_LOW status.
3163 * This function should be called from contexts where we cannot sleep, and will
3164 * complain if the GPIO chip functions potentially sleep.
3166 int gpiod_set_raw_array_value(unsigned int array_size,
3167 struct gpio_desc **desc_array, int *value_array)
3171 return gpiod_set_array_value_complex(true, false, array_size,
3172 desc_array, value_array);
3174 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3177 * gpiod_set_array_value() - assign values to an array of GPIOs
3178 * @array_size: number of elements in the descriptor / value arrays
3179 * @desc_array: array of GPIO descriptors whose values will be assigned
3180 * @value_array: array of values to assign
3182 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3185 * This function should be called from contexts where we cannot sleep, and will
3186 * complain if the GPIO chip functions potentially sleep.
3188 void gpiod_set_array_value(unsigned int array_size,
3189 struct gpio_desc **desc_array, int *value_array)
3193 gpiod_set_array_value_complex(false, false, array_size, desc_array,
3196 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3199 * gpiod_cansleep() - report whether gpio value access may sleep
3200 * @desc: gpio to check
3203 int gpiod_cansleep(const struct gpio_desc *desc)
3205 VALIDATE_DESC(desc);
3206 return desc->gdev->chip->can_sleep;
3208 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3211 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3212 * @desc: gpio to set the consumer name on
3213 * @name: the new consumer name
3215 void gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3217 VALIDATE_DESC_VOID(desc);
3218 /* Just overwrite whatever the previous name was */
3221 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3224 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3225 * @desc: gpio whose IRQ will be returned (already requested)
3227 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3230 int gpiod_to_irq(const struct gpio_desc *desc)
3232 struct gpio_chip *chip;
3236 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3237 * requires this function to not return zero on an invalid descriptor
3238 * but rather a negative error number.
3240 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3243 chip = desc->gdev->chip;
3244 offset = gpio_chip_hwgpio(desc);
3246 int retirq = chip->to_irq(chip, offset);
3248 /* Zero means NO_IRQ */
3256 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3259 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3260 * @chip: the chip the GPIO to lock belongs to
3261 * @offset: the offset of the GPIO to lock as IRQ
3263 * This is used directly by GPIO drivers that want to lock down
3264 * a certain GPIO line to be used for IRQs.
3266 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
3268 struct gpio_desc *desc;
3270 desc = gpiochip_get_desc(chip, offset);
3272 return PTR_ERR(desc);
3275 * If it's fast: flush the direction setting if something changed
3278 if (!chip->can_sleep && chip->get_direction) {
3279 int dir = gpiod_get_direction(desc);
3282 chip_err(chip, "%s: cannot get GPIO direction\n",
3288 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
3290 "%s: tried to flag a GPIO set as output for IRQ\n",
3295 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3298 * If the consumer has not set up a label (such as when the
3299 * IRQ is referenced from .to_irq()) we set up a label here
3300 * so it is clear this is used as an interrupt.
3303 desc_set_label(desc, "interrupt");
3307 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3310 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3311 * @chip: the chip the GPIO to lock belongs to
3312 * @offset: the offset of the GPIO to lock as IRQ
3314 * This is used directly by GPIO drivers that want to indicate
3315 * that a certain GPIO is no longer used exclusively for IRQ.
3317 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
3319 struct gpio_desc *desc;
3321 desc = gpiochip_get_desc(chip, offset);
3325 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3327 /* If we only had this marking, erase it */
3328 if (desc->label && !strcmp(desc->label, "interrupt"))
3329 desc_set_label(desc, NULL);
3331 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3333 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
3335 if (offset >= chip->ngpio)
3338 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
3340 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3342 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
3344 if (offset >= chip->ngpio)
3347 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
3349 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3351 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
3353 if (offset >= chip->ngpio)
3356 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
3358 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3360 bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
3362 if (offset >= chip->ngpio)
3365 return !test_bit(FLAG_TRANSITORY, &chip->gpiodev->descs[offset].flags);
3367 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3370 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3371 * @desc: gpio whose value will be returned
3373 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3374 * its ACTIVE_LOW status, or negative errno on failure.
3376 * This function is to be called from contexts that can sleep.
3378 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3380 might_sleep_if(extra_checks);
3381 VALIDATE_DESC(desc);
3382 return gpiod_get_raw_value_commit(desc);
3384 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3387 * gpiod_get_value_cansleep() - return a gpio's value
3388 * @desc: gpio whose value will be returned
3390 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3391 * account, or negative errno on failure.
3393 * This function is to be called from contexts that can sleep.
3395 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3399 might_sleep_if(extra_checks);
3400 VALIDATE_DESC(desc);
3401 value = gpiod_get_raw_value_commit(desc);
3405 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3410 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3413 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3414 * @array_size: number of elements in the descriptor / value arrays
3415 * @desc_array: array of GPIO descriptors whose values will be read
3416 * @value_array: array to store the read values
3418 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3419 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3420 * else an error code.
3422 * This function is to be called from contexts that can sleep.
3424 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3425 struct gpio_desc **desc_array,
3428 might_sleep_if(extra_checks);
3431 return gpiod_get_array_value_complex(true, true, array_size,
3432 desc_array, value_array);
3434 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3437 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3438 * @array_size: number of elements in the descriptor / value arrays
3439 * @desc_array: array of GPIO descriptors whose values will be read
3440 * @value_array: array to store the read values
3442 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3443 * into account. Return 0 in case of success, else an error code.
3445 * This function is to be called from contexts that can sleep.
3447 int gpiod_get_array_value_cansleep(unsigned int array_size,
3448 struct gpio_desc **desc_array,
3451 might_sleep_if(extra_checks);
3454 return gpiod_get_array_value_complex(false, true, array_size,
3455 desc_array, value_array);
3457 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3460 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3461 * @desc: gpio whose value will be assigned
3462 * @value: value to assign
3464 * Set the raw value of the GPIO, i.e. the value of its physical line without
3465 * regard for its ACTIVE_LOW status.
3467 * This function is to be called from contexts that can sleep.
3469 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3471 might_sleep_if(extra_checks);
3472 VALIDATE_DESC_VOID(desc);
3473 gpiod_set_raw_value_commit(desc, value);
3475 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3478 * gpiod_set_value_cansleep() - assign a gpio's value
3479 * @desc: gpio whose value will be assigned
3480 * @value: value to assign
3482 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3485 * This function is to be called from contexts that can sleep.
3487 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3489 might_sleep_if(extra_checks);
3490 VALIDATE_DESC_VOID(desc);
3491 gpiod_set_value_nocheck(desc, value);
3493 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3496 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3497 * @array_size: number of elements in the descriptor / value arrays
3498 * @desc_array: array of GPIO descriptors whose values will be assigned
3499 * @value_array: array of values to assign
3501 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3502 * without regard for their ACTIVE_LOW status.
3504 * This function is to be called from contexts that can sleep.
3506 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3507 struct gpio_desc **desc_array,
3510 might_sleep_if(extra_checks);
3513 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3516 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3519 * gpiod_add_lookup_tables() - register GPIO device consumers
3520 * @tables: list of tables of consumers to register
3521 * @n: number of tables in the list
3523 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3527 mutex_lock(&gpio_lookup_lock);
3529 for (i = 0; i < n; i++)
3530 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3532 mutex_unlock(&gpio_lookup_lock);
3536 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3537 * @array_size: number of elements in the descriptor / value arrays
3538 * @desc_array: array of GPIO descriptors whose values will be assigned
3539 * @value_array: array of values to assign
3541 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3544 * This function is to be called from contexts that can sleep.
3546 void gpiod_set_array_value_cansleep(unsigned int array_size,
3547 struct gpio_desc **desc_array,
3550 might_sleep_if(extra_checks);
3553 gpiod_set_array_value_complex(false, true, array_size, desc_array,
3556 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3559 * gpiod_add_lookup_table() - register GPIO device consumers
3560 * @table: table of consumers to register
3562 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3564 mutex_lock(&gpio_lookup_lock);
3566 list_add_tail(&table->list, &gpio_lookup_list);
3568 mutex_unlock(&gpio_lookup_lock);
3570 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3573 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3574 * @table: table of consumers to unregister
3576 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3578 mutex_lock(&gpio_lookup_lock);
3580 list_del(&table->list);
3582 mutex_unlock(&gpio_lookup_lock);
3584 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3587 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
3588 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
3590 void gpiod_add_hogs(struct gpiod_hog *hogs)
3592 struct gpio_chip *chip;
3593 struct gpiod_hog *hog;
3595 mutex_lock(&gpio_machine_hogs_mutex);
3597 for (hog = &hogs[0]; hog->chip_label; hog++) {
3598 list_add_tail(&hog->list, &gpio_machine_hogs);
3601 * The chip may have been registered earlier, so check if it
3602 * exists and, if so, try to hog the line now.
3604 chip = find_chip_by_name(hog->chip_label);
3606 gpiochip_machine_hog(chip, hog);
3609 mutex_unlock(&gpio_machine_hogs_mutex);
3611 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
3613 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3615 const char *dev_id = dev ? dev_name(dev) : NULL;
3616 struct gpiod_lookup_table *table;
3618 mutex_lock(&gpio_lookup_lock);
3620 list_for_each_entry(table, &gpio_lookup_list, list) {
3621 if (table->dev_id && dev_id) {
3623 * Valid strings on both ends, must be identical to have
3626 if (!strcmp(table->dev_id, dev_id))
3630 * One of the pointers is NULL, so both must be to have
3633 if (dev_id == table->dev_id)
3640 mutex_unlock(&gpio_lookup_lock);
3644 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3646 enum gpio_lookup_flags *flags)
3648 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3649 struct gpiod_lookup_table *table;
3650 struct gpiod_lookup *p;
3652 table = gpiod_find_lookup_table(dev);
3656 for (p = &table->table[0]; p->chip_label; p++) {
3657 struct gpio_chip *chip;
3659 /* idx must always match exactly */
3663 /* If the lookup entry has a con_id, require exact match */
3664 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3667 chip = find_chip_by_name(p->chip_label);
3671 * As the lookup table indicates a chip with
3672 * p->chip_label should exist, assume it may
3673 * still appear later and let the interested
3674 * consumer be probed again or let the Deferred
3675 * Probe infrastructure handle the error.
3677 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
3679 return ERR_PTR(-EPROBE_DEFER);
3682 if (chip->ngpio <= p->chip_hwnum) {
3684 "requested GPIO %d is out of range [0..%d] for chip %s\n",
3685 idx, chip->ngpio, chip->label);
3686 return ERR_PTR(-EINVAL);
3689 desc = gpiochip_get_desc(chip, p->chip_hwnum);
3698 static int dt_gpio_count(struct device *dev, const char *con_id)
3704 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3706 snprintf(propname, sizeof(propname), "%s-%s",
3707 con_id, gpio_suffixes[i]);
3709 snprintf(propname, sizeof(propname), "%s",
3712 ret = of_gpio_named_count(dev->of_node, propname);
3716 return ret ? ret : -ENOENT;
3719 static int platform_gpio_count(struct device *dev, const char *con_id)
3721 struct gpiod_lookup_table *table;
3722 struct gpiod_lookup *p;
3723 unsigned int count = 0;
3725 table = gpiod_find_lookup_table(dev);
3729 for (p = &table->table[0]; p->chip_label; p++) {
3730 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3731 (!con_id && !p->con_id))
3741 * gpiod_count - return the number of GPIOs associated with a device / function
3742 * or -ENOENT if no GPIO has been assigned to the requested function
3743 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3744 * @con_id: function within the GPIO consumer
3746 int gpiod_count(struct device *dev, const char *con_id)
3748 int count = -ENOENT;
3750 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
3751 count = dt_gpio_count(dev, con_id);
3752 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
3753 count = acpi_gpio_count(dev, con_id);
3756 count = platform_gpio_count(dev, con_id);
3760 EXPORT_SYMBOL_GPL(gpiod_count);
3763 * gpiod_get - obtain a GPIO for a given GPIO function
3764 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3765 * @con_id: function within the GPIO consumer
3766 * @flags: optional GPIO initialization flags
3768 * Return the GPIO descriptor corresponding to the function con_id of device
3769 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3770 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3772 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3773 enum gpiod_flags flags)
3775 return gpiod_get_index(dev, con_id, 0, flags);
3777 EXPORT_SYMBOL_GPL(gpiod_get);
3780 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3781 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3782 * @con_id: function within the GPIO consumer
3783 * @flags: optional GPIO initialization flags
3785 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3786 * the requested function it will return NULL. This is convenient for drivers
3787 * that need to handle optional GPIOs.
3789 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3791 enum gpiod_flags flags)
3793 return gpiod_get_index_optional(dev, con_id, 0, flags);
3795 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3799 * gpiod_configure_flags - helper function to configure a given GPIO
3800 * @desc: gpio whose value will be assigned
3801 * @con_id: function within the GPIO consumer
3802 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3804 * @dflags: gpiod_flags - optional GPIO initialization flags
3806 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3807 * requested function and/or index, or another IS_ERR() code if an error
3808 * occurred while trying to acquire the GPIO.
3810 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3811 unsigned long lflags, enum gpiod_flags dflags)
3815 if (lflags & GPIO_ACTIVE_LOW)
3816 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3818 if (lflags & GPIO_OPEN_DRAIN)
3819 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3820 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
3822 * This enforces open drain mode from the consumer side.
3823 * This is necessary for some busses like I2C, but the lookup
3824 * should *REALLY* have specified them as open drain in the
3825 * first place, so print a little warning here.
3827 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3829 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
3832 if (lflags & GPIO_OPEN_SOURCE)
3833 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3835 status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
3839 /* No particular flag request, return here... */
3840 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3841 pr_debug("no flags found for %s\n", con_id);
3846 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3847 status = gpiod_direction_output(desc,
3848 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3850 status = gpiod_direction_input(desc);
3856 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3857 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3858 * @con_id: function within the GPIO consumer
3859 * @idx: index of the GPIO to obtain in the consumer
3860 * @flags: optional GPIO initialization flags
3862 * This variant of gpiod_get() allows to access GPIOs other than the first
3863 * defined one for functions that define several GPIOs.
3865 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3866 * requested function and/or index, or another IS_ERR() code if an error
3867 * occurred while trying to acquire the GPIO.
3869 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3872 enum gpiod_flags flags)
3874 struct gpio_desc *desc = NULL;
3876 enum gpio_lookup_flags lookupflags = 0;
3877 /* Maybe we have a device name, maybe not */
3878 const char *devname = dev ? dev_name(dev) : "?";
3880 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3883 /* Using device tree? */
3884 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
3885 dev_dbg(dev, "using device tree for GPIO lookup\n");
3886 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3887 } else if (ACPI_COMPANION(dev)) {
3888 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3889 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
3894 * Either we are not using DT or ACPI, or their lookup did not return
3895 * a result. In that case, use platform lookup as a fallback.
3897 if (!desc || desc == ERR_PTR(-ENOENT)) {
3898 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3899 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3903 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
3908 * If a connection label was passed use that, else attempt to use
3909 * the device name as label
3911 status = gpiod_request(desc, con_id ? con_id : devname);
3913 if (status == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
3915 * This happens when there are several consumers for
3916 * the same GPIO line: we just return here without
3917 * further initialization. It is a bit if a hack.
3918 * This is necessary to support fixed regulators.
3920 * FIXME: Make this more sane and safe.
3922 dev_info(dev, "nonexclusive access to GPIO for %s\n",
3923 con_id ? con_id : devname);
3926 return ERR_PTR(status);
3930 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3932 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3934 return ERR_PTR(status);
3939 EXPORT_SYMBOL_GPL(gpiod_get_index);
3942 * gpiod_get_from_of_node() - obtain a GPIO from an OF node
3943 * @node: handle of the OF node
3944 * @propname: name of the DT property representing the GPIO
3945 * @index: index of the GPIO to obtain for the consumer
3946 * @dflags: GPIO initialization flags
3947 * @label: label to attach to the requested GPIO
3950 * On successful request the GPIO pin is configured in accordance with
3951 * provided @dflags. If the node does not have the requested GPIO
3952 * property, NULL is returned.
3954 * In case of error an ERR_PTR() is returned.
3956 struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
3957 const char *propname, int index,
3958 enum gpiod_flags dflags,
3961 struct gpio_desc *desc;
3962 unsigned long lflags = 0;
3963 enum of_gpio_flags flags;
3964 bool active_low = false;
3965 bool single_ended = false;
3966 bool open_drain = false;
3967 bool transitory = false;
3970 desc = of_get_named_gpiod_flags(node, propname,
3973 if (!desc || IS_ERR(desc)) {
3974 /* If it is not there, just return NULL */
3975 if (PTR_ERR(desc) == -ENOENT)
3980 active_low = flags & OF_GPIO_ACTIVE_LOW;
3981 single_ended = flags & OF_GPIO_SINGLE_ENDED;
3982 open_drain = flags & OF_GPIO_OPEN_DRAIN;
3983 transitory = flags & OF_GPIO_TRANSITORY;
3985 ret = gpiod_request(desc, label);
3987 return ERR_PTR(ret);
3990 lflags |= GPIO_ACTIVE_LOW;
3994 lflags |= GPIO_OPEN_DRAIN;
3996 lflags |= GPIO_OPEN_SOURCE;
4000 lflags |= GPIO_TRANSITORY;
4002 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4005 return ERR_PTR(ret);
4010 EXPORT_SYMBOL(gpiod_get_from_of_node);
4013 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
4014 * @fwnode: handle of the firmware node
4015 * @propname: name of the firmware property representing the GPIO
4016 * @index: index of the GPIO to obtain for the consumer
4017 * @dflags: GPIO initialization flags
4018 * @label: label to attach to the requested GPIO
4020 * This function can be used for drivers that get their configuration
4021 * from opaque firmware.
4023 * The function properly finds the corresponding GPIO using whatever is the
4024 * underlying firmware interface and then makes sure that the GPIO
4025 * descriptor is requested before it is returned to the caller.
4028 * On successful request the GPIO pin is configured in accordance with
4031 * In case of error an ERR_PTR() is returned.
4033 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
4034 const char *propname, int index,
4035 enum gpiod_flags dflags,
4038 struct gpio_desc *desc = ERR_PTR(-ENODEV);
4039 unsigned long lflags = 0;
4043 return ERR_PTR(-EINVAL);
4045 if (is_of_node(fwnode)) {
4046 desc = gpiod_get_from_of_node(to_of_node(fwnode),
4051 } else if (is_acpi_node(fwnode)) {
4052 struct acpi_gpio_info info;
4054 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4058 acpi_gpio_update_gpiod_flags(&dflags, &info);
4060 if (info.polarity == GPIO_ACTIVE_LOW)
4061 lflags |= GPIO_ACTIVE_LOW;
4064 /* Currently only ACPI takes this path */
4065 ret = gpiod_request(desc, label);
4067 return ERR_PTR(ret);
4069 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4072 return ERR_PTR(ret);
4077 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4080 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4082 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4083 * @con_id: function within the GPIO consumer
4084 * @index: index of the GPIO to obtain in the consumer
4085 * @flags: optional GPIO initialization flags
4087 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4088 * specified index was assigned to the requested function it will return NULL.
4089 * This is convenient for drivers that need to handle optional GPIOs.
4091 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4094 enum gpiod_flags flags)
4096 struct gpio_desc *desc;
4098 desc = gpiod_get_index(dev, con_id, index, flags);
4100 if (PTR_ERR(desc) == -ENOENT)
4106 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4109 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4110 * @desc: gpio whose value will be assigned
4111 * @name: gpio line name
4112 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
4114 * @dflags: gpiod_flags - optional GPIO initialization flags
4116 int gpiod_hog(struct gpio_desc *desc, const char *name,
4117 unsigned long lflags, enum gpiod_flags dflags)
4119 struct gpio_chip *chip;
4120 struct gpio_desc *local_desc;
4124 chip = gpiod_to_chip(desc);
4125 hwnum = gpio_chip_hwgpio(desc);
4127 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
4128 if (IS_ERR(local_desc)) {
4129 status = PTR_ERR(local_desc);
4130 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4131 name, chip->label, hwnum, status);
4135 status = gpiod_configure_flags(desc, name, lflags, dflags);
4137 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
4138 name, chip->label, hwnum, status);
4139 gpiochip_free_own_desc(desc);
4143 /* Mark GPIO as hogged so it can be identified and removed later */
4144 set_bit(FLAG_IS_HOGGED, &desc->flags);
4146 pr_info("GPIO line %d (%s) hogged as %s%s\n",
4147 desc_to_gpio(desc), name,
4148 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4149 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
4150 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
4156 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4157 * @chip: gpio chip to act on
4159 * This is only used by of_gpiochip_remove to free hogged gpios
4161 static void gpiochip_free_hogs(struct gpio_chip *chip)
4165 for (id = 0; id < chip->ngpio; id++) {
4166 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
4167 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
4172 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4173 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4174 * @con_id: function within the GPIO consumer
4175 * @flags: optional GPIO initialization flags
4177 * This function acquires all the GPIOs defined under a given function.
4179 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4180 * no GPIO has been assigned to the requested function, or another IS_ERR()
4181 * code if an error occurred while trying to acquire the GPIOs.
4183 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4185 enum gpiod_flags flags)
4187 struct gpio_desc *desc;
4188 struct gpio_descs *descs;
4191 count = gpiod_count(dev, con_id);
4193 return ERR_PTR(count);
4195 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4197 return ERR_PTR(-ENOMEM);
4199 for (descs->ndescs = 0; descs->ndescs < count; ) {
4200 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4202 gpiod_put_array(descs);
4203 return ERR_CAST(desc);
4205 descs->desc[descs->ndescs] = desc;
4210 EXPORT_SYMBOL_GPL(gpiod_get_array);
4213 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4215 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4216 * @con_id: function within the GPIO consumer
4217 * @flags: optional GPIO initialization flags
4219 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4220 * assigned to the requested function it will return NULL.
4222 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4224 enum gpiod_flags flags)
4226 struct gpio_descs *descs;
4228 descs = gpiod_get_array(dev, con_id, flags);
4229 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
4234 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4237 * gpiod_put - dispose of a GPIO descriptor
4238 * @desc: GPIO descriptor to dispose of
4240 * No descriptor can be used after gpiod_put() has been called on it.
4242 void gpiod_put(struct gpio_desc *desc)
4246 EXPORT_SYMBOL_GPL(gpiod_put);
4249 * gpiod_put_array - dispose of multiple GPIO descriptors
4250 * @descs: struct gpio_descs containing an array of descriptors
4252 void gpiod_put_array(struct gpio_descs *descs)
4256 for (i = 0; i < descs->ndescs; i++)
4257 gpiod_put(descs->desc[i]);
4261 EXPORT_SYMBOL_GPL(gpiod_put_array);
4263 static int __init gpiolib_dev_init(void)
4267 /* Register GPIO sysfs bus */
4268 ret = bus_register(&gpio_bus_type);
4270 pr_err("gpiolib: could not register GPIO bus type\n");
4274 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
4276 pr_err("gpiolib: failed to allocate char dev region\n");
4277 bus_unregister(&gpio_bus_type);
4279 gpiolib_initialized = true;
4280 gpiochip_setup_devs();
4284 core_initcall(gpiolib_dev_init);
4286 #ifdef CONFIG_DEBUG_FS
4288 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4291 struct gpio_chip *chip = gdev->chip;
4292 unsigned gpio = gdev->base;
4293 struct gpio_desc *gdesc = &gdev->descs[0];
4297 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4298 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4300 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4306 gpiod_get_direction(gdesc);
4307 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4308 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4309 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
4310 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4311 is_out ? "out" : "in ",
4312 chip->get ? (chip->get(chip, i) ? "hi" : "lo") : "? ",
4313 is_irq ? "IRQ" : " ");
4314 seq_printf(s, "\n");
4318 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4320 unsigned long flags;
4321 struct gpio_device *gdev = NULL;
4322 loff_t index = *pos;
4326 spin_lock_irqsave(&gpio_lock, flags);
4327 list_for_each_entry(gdev, &gpio_devices, list)
4329 spin_unlock_irqrestore(&gpio_lock, flags);
4332 spin_unlock_irqrestore(&gpio_lock, flags);
4337 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4339 unsigned long flags;
4340 struct gpio_device *gdev = v;
4343 spin_lock_irqsave(&gpio_lock, flags);
4344 if (list_is_last(&gdev->list, &gpio_devices))
4347 ret = list_entry(gdev->list.next, struct gpio_device, list);
4348 spin_unlock_irqrestore(&gpio_lock, flags);
4356 static void gpiolib_seq_stop(struct seq_file *s, void *v)
4360 static int gpiolib_seq_show(struct seq_file *s, void *v)
4362 struct gpio_device *gdev = v;
4363 struct gpio_chip *chip = gdev->chip;
4364 struct device *parent;
4367 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4368 dev_name(&gdev->dev));
4372 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4373 dev_name(&gdev->dev),
4374 gdev->base, gdev->base + gdev->ngpio - 1);
4375 parent = chip->parent;
4377 seq_printf(s, ", parent: %s/%s",
4378 parent->bus ? parent->bus->name : "no-bus",
4381 seq_printf(s, ", %s", chip->label);
4382 if (chip->can_sleep)
4383 seq_printf(s, ", can sleep");
4384 seq_printf(s, ":\n");
4387 chip->dbg_show(s, chip);
4389 gpiolib_dbg_show(s, gdev);
4394 static const struct seq_operations gpiolib_seq_ops = {
4395 .start = gpiolib_seq_start,
4396 .next = gpiolib_seq_next,
4397 .stop = gpiolib_seq_stop,
4398 .show = gpiolib_seq_show,
4401 static int gpiolib_open(struct inode *inode, struct file *file)
4403 return seq_open(file, &gpiolib_seq_ops);
4406 static const struct file_operations gpiolib_operations = {
4407 .owner = THIS_MODULE,
4408 .open = gpiolib_open,
4410 .llseek = seq_lseek,
4411 .release = seq_release,
4414 static int __init gpiolib_debugfs_init(void)
4416 /* /sys/kernel/debug/gpio */
4417 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
4418 NULL, NULL, &gpiolib_operations);
4421 subsys_initcall(gpiolib_debugfs_init);
4423 #endif /* DEBUG_FS */