1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/bitmap.h>
3 #include <linux/kernel.h>
4 #include <linux/module.h>
5 #include <linux/interrupt.h>
7 #include <linux/spinlock.h>
8 #include <linux/list.h>
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/debugfs.h>
12 #include <linux/seq_file.h>
13 #include <linux/gpio.h>
14 #include <linux/of_gpio.h>
15 #include <linux/idr.h>
16 #include <linux/slab.h>
17 #include <linux/acpi.h>
18 #include <linux/gpio/driver.h>
19 #include <linux/gpio/machine.h>
20 #include <linux/pinctrl/consumer.h>
21 #include <linux/cdev.h>
23 #include <linux/uaccess.h>
24 #include <linux/compat.h>
25 #include <linux/anon_inodes.h>
26 #include <linux/file.h>
27 #include <linux/kfifo.h>
28 #include <linux/poll.h>
29 #include <linux/timekeeping.h>
30 #include <uapi/linux/gpio.h>
34 #define CREATE_TRACE_POINTS
35 #include <trace/events/gpio.h>
37 /* Implementation infrastructure for GPIO interfaces.
39 * The GPIO programming interface allows for inlining speed-critical
40 * get/set operations for common cases, so that access to SOC-integrated
41 * GPIOs can sometimes cost only an instruction or two per bit.
45 /* When debugging, extend minimal trust to callers and platform code.
46 * Also emit diagnostic messages that may help initial bringup, when
47 * board setup or driver bugs are most common.
49 * Otherwise, minimize overhead in what may be bitbanging codepaths.
52 #define extra_checks 1
54 #define extra_checks 0
57 /* Device and char device-related information */
58 static DEFINE_IDA(gpio_ida);
59 static dev_t gpio_devt;
60 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
61 static struct bus_type gpio_bus_type = {
66 * Number of GPIOs to use for the fast path in set array
68 #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
70 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
71 * While any GPIO is requested, its gpio_chip is not removable;
72 * each GPIO's "requested" flag serves as a lock and refcount.
74 DEFINE_SPINLOCK(gpio_lock);
76 static DEFINE_MUTEX(gpio_lookup_lock);
77 static LIST_HEAD(gpio_lookup_list);
78 LIST_HEAD(gpio_devices);
80 static DEFINE_MUTEX(gpio_machine_hogs_mutex);
81 static LIST_HEAD(gpio_machine_hogs);
83 static void gpiochip_free_hogs(struct gpio_chip *chip);
84 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
85 struct lock_class_key *lock_key,
86 struct lock_class_key *request_key);
87 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
88 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
89 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
91 static bool gpiolib_initialized;
93 static inline void desc_set_label(struct gpio_desc *d, const char *label)
99 * gpio_to_desc - Convert a GPIO number to its descriptor
100 * @gpio: global GPIO number
103 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
104 * with the given number exists in the system.
106 struct gpio_desc *gpio_to_desc(unsigned gpio)
108 struct gpio_device *gdev;
111 spin_lock_irqsave(&gpio_lock, flags);
113 list_for_each_entry(gdev, &gpio_devices, list) {
114 if (gdev->base <= gpio &&
115 gdev->base + gdev->ngpio > gpio) {
116 spin_unlock_irqrestore(&gpio_lock, flags);
117 return &gdev->descs[gpio - gdev->base];
121 spin_unlock_irqrestore(&gpio_lock, flags);
123 if (!gpio_is_valid(gpio))
124 WARN(1, "invalid GPIO %d\n", gpio);
128 EXPORT_SYMBOL_GPL(gpio_to_desc);
131 * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
132 * hardware number for this chip
134 * @hwnum: hardware number of the GPIO for this chip
137 * A pointer to the GPIO descriptor or %ERR_PTR(-EINVAL) if no GPIO exists
138 * in the given chip for the specified hardware number.
140 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
143 struct gpio_device *gdev = chip->gpiodev;
145 if (hwnum >= gdev->ngpio)
146 return ERR_PTR(-EINVAL);
148 return &gdev->descs[hwnum];
152 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
153 * @desc: GPIO descriptor
155 * This should disappear in the future but is needed since we still
156 * use GPIO numbers for error messages and sysfs nodes.
159 * The global GPIO number for the GPIO specified by its descriptor.
161 int desc_to_gpio(const struct gpio_desc *desc)
163 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
165 EXPORT_SYMBOL_GPL(desc_to_gpio);
169 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
170 * @desc: descriptor to return the chip of
172 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
174 if (!desc || !desc->gdev)
176 return desc->gdev->chip;
178 EXPORT_SYMBOL_GPL(gpiod_to_chip);
180 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
181 static int gpiochip_find_base(int ngpio)
183 struct gpio_device *gdev;
184 int base = ARCH_NR_GPIOS - ngpio;
186 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
187 /* found a free space? */
188 if (gdev->base + gdev->ngpio <= base)
191 /* nope, check the space right before the chip */
192 base = gdev->base - ngpio;
195 if (gpio_is_valid(base)) {
196 pr_debug("%s: found new base at %d\n", __func__, base);
199 pr_err("%s: cannot find free range\n", __func__);
205 * gpiod_get_direction - return the current direction of a GPIO
206 * @desc: GPIO to get the direction of
208 * Returns 0 for output, 1 for input, or an error code in case of error.
210 * This function may sleep if gpiod_cansleep() is true.
212 int gpiod_get_direction(struct gpio_desc *desc)
214 struct gpio_chip *chip;
218 chip = gpiod_to_chip(desc);
219 offset = gpio_chip_hwgpio(desc);
221 if (!chip->get_direction)
224 status = chip->get_direction(chip, offset);
226 /* GPIOF_DIR_IN, or other positive */
228 clear_bit(FLAG_IS_OUT, &desc->flags);
232 set_bit(FLAG_IS_OUT, &desc->flags);
236 EXPORT_SYMBOL_GPL(gpiod_get_direction);
239 * Add a new chip to the global chips list, keeping the list of chips sorted
240 * by range(means [base, base + ngpio - 1]) order.
242 * Return -EBUSY if the new chip overlaps with some other chip's integer
245 static int gpiodev_add_to_list(struct gpio_device *gdev)
247 struct gpio_device *prev, *next;
249 if (list_empty(&gpio_devices)) {
250 /* initial entry in list */
251 list_add_tail(&gdev->list, &gpio_devices);
255 next = list_entry(gpio_devices.next, struct gpio_device, list);
256 if (gdev->base + gdev->ngpio <= next->base) {
257 /* add before first entry */
258 list_add(&gdev->list, &gpio_devices);
262 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
263 if (prev->base + prev->ngpio <= gdev->base) {
264 /* add behind last entry */
265 list_add_tail(&gdev->list, &gpio_devices);
269 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
270 /* at the end of the list */
271 if (&next->list == &gpio_devices)
274 /* add between prev and next */
275 if (prev->base + prev->ngpio <= gdev->base
276 && gdev->base + gdev->ngpio <= next->base) {
277 list_add(&gdev->list, &prev->list);
282 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
287 * Convert a GPIO name to its descriptor
289 static struct gpio_desc *gpio_name_to_desc(const char * const name)
291 struct gpio_device *gdev;
294 spin_lock_irqsave(&gpio_lock, flags);
296 list_for_each_entry(gdev, &gpio_devices, list) {
299 for (i = 0; i != gdev->ngpio; ++i) {
300 struct gpio_desc *desc = &gdev->descs[i];
302 if (!desc->name || !name)
305 if (!strcmp(desc->name, name)) {
306 spin_unlock_irqrestore(&gpio_lock, flags);
312 spin_unlock_irqrestore(&gpio_lock, flags);
318 * Takes the names from gc->names and checks if they are all unique. If they
319 * are, they are assigned to their gpio descriptors.
321 * Warning if one of the names is already used for a different GPIO.
323 static int gpiochip_set_desc_names(struct gpio_chip *gc)
325 struct gpio_device *gdev = gc->gpiodev;
331 /* First check all names if they are unique */
332 for (i = 0; i != gc->ngpio; ++i) {
333 struct gpio_desc *gpio;
335 gpio = gpio_name_to_desc(gc->names[i]);
338 "Detected name collision for GPIO name '%s'\n",
342 /* Then add all names to the GPIO descriptors */
343 for (i = 0; i != gc->ngpio; ++i)
344 gdev->descs[i].name = gc->names[i];
349 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *chip)
353 p = kmalloc_array(BITS_TO_LONGS(chip->ngpio), sizeof(*p), GFP_KERNEL);
357 /* Assume by default all GPIOs are valid */
358 bitmap_fill(p, chip->ngpio);
363 static int gpiochip_alloc_valid_mask(struct gpio_chip *gpiochip)
365 #ifdef CONFIG_OF_GPIO
367 struct device_node *np = gpiochip->of_node;
369 size = of_property_count_u32_elems(np, "gpio-reserved-ranges");
370 if (size > 0 && size % 2 == 0)
371 gpiochip->need_valid_mask = true;
374 if (!gpiochip->need_valid_mask)
377 gpiochip->valid_mask = gpiochip_allocate_mask(gpiochip);
378 if (!gpiochip->valid_mask)
384 static int gpiochip_init_valid_mask(struct gpio_chip *gpiochip)
386 if (gpiochip->init_valid_mask)
387 return gpiochip->init_valid_mask(gpiochip);
392 static void gpiochip_free_valid_mask(struct gpio_chip *gpiochip)
394 kfree(gpiochip->valid_mask);
395 gpiochip->valid_mask = NULL;
398 bool gpiochip_line_is_valid(const struct gpio_chip *gpiochip,
401 /* No mask means all valid */
402 if (likely(!gpiochip->valid_mask))
404 return test_bit(offset, gpiochip->valid_mask);
406 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
409 * GPIO line handle management
413 * struct linehandle_state - contains the state of a userspace handle
414 * @gdev: the GPIO device the handle pertains to
415 * @label: consumer label used to tag descriptors
416 * @descs: the GPIO descriptors held by this handle
417 * @numdescs: the number of descriptors held in the descs array
419 struct linehandle_state {
420 struct gpio_device *gdev;
422 struct gpio_desc *descs[GPIOHANDLES_MAX];
426 #define GPIOHANDLE_REQUEST_VALID_FLAGS \
427 (GPIOHANDLE_REQUEST_INPUT | \
428 GPIOHANDLE_REQUEST_OUTPUT | \
429 GPIOHANDLE_REQUEST_ACTIVE_LOW | \
430 GPIOHANDLE_REQUEST_OPEN_DRAIN | \
431 GPIOHANDLE_REQUEST_OPEN_SOURCE)
433 static long linehandle_ioctl(struct file *filep, unsigned int cmd,
436 struct linehandle_state *lh = filep->private_data;
437 void __user *ip = (void __user *)arg;
438 struct gpiohandle_data ghd;
439 DECLARE_BITMAP(vals, GPIOHANDLES_MAX);
442 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
443 /* NOTE: It's ok to read values of output lines. */
444 int ret = gpiod_get_array_value_complex(false,
453 memset(&ghd, 0, sizeof(ghd));
454 for (i = 0; i < lh->numdescs; i++)
455 ghd.values[i] = test_bit(i, vals);
457 if (copy_to_user(ip, &ghd, sizeof(ghd)))
461 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
463 * All line descriptors were created at once with the same
464 * flags so just check if the first one is really output.
466 if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags))
469 if (copy_from_user(&ghd, ip, sizeof(ghd)))
472 /* Clamp all values to [0,1] */
473 for (i = 0; i < lh->numdescs; i++)
474 __assign_bit(i, vals, ghd.values[i]);
476 /* Reuse the array setting function */
477 return gpiod_set_array_value_complex(false,
488 static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
491 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
495 static int linehandle_release(struct inode *inode, struct file *filep)
497 struct linehandle_state *lh = filep->private_data;
498 struct gpio_device *gdev = lh->gdev;
501 for (i = 0; i < lh->numdescs; i++)
502 gpiod_free(lh->descs[i]);
505 put_device(&gdev->dev);
509 static const struct file_operations linehandle_fileops = {
510 .release = linehandle_release,
511 .owner = THIS_MODULE,
512 .llseek = noop_llseek,
513 .unlocked_ioctl = linehandle_ioctl,
515 .compat_ioctl = linehandle_ioctl_compat,
519 static int linehandle_create(struct gpio_device *gdev, void __user *ip)
521 struct gpiohandle_request handlereq;
522 struct linehandle_state *lh;
524 int fd, i, count = 0, ret;
527 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
529 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
532 lflags = handlereq.flags;
534 /* Return an error if an unknown flag is set */
535 if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
539 * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
540 * the hardware actually supports enabling both at the same time the
541 * electrical result would be disastrous.
543 if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
544 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
547 /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
548 if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) &&
549 ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
550 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
553 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
557 get_device(&gdev->dev);
559 /* Make sure this is terminated */
560 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
561 if (strlen(handlereq.consumer_label)) {
562 lh->label = kstrdup(handlereq.consumer_label,
570 /* Request each GPIO */
571 for (i = 0; i < handlereq.lines; i++) {
572 u32 offset = handlereq.lineoffsets[i];
573 struct gpio_desc *desc;
575 if (offset >= gdev->ngpio) {
580 desc = &gdev->descs[offset];
581 ret = gpiod_request(desc, lh->label);
587 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
588 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
589 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
590 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
591 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
592 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
594 ret = gpiod_set_transitory(desc, false);
599 * Lines have to be requested explicitly for input
600 * or output, else the line will be treated "as is".
602 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
603 int val = !!handlereq.default_values[i];
605 ret = gpiod_direction_output(desc, val);
608 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
609 ret = gpiod_direction_input(desc);
613 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
616 /* Let i point at the last handle */
618 lh->numdescs = handlereq.lines;
620 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
626 file = anon_inode_getfile("gpio-linehandle",
629 O_RDONLY | O_CLOEXEC);
632 goto out_put_unused_fd;
636 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
638 * fput() will trigger the release() callback, so do not go onto
639 * the regular error cleanup path here.
646 fd_install(fd, file);
648 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
656 for (i = 0; i < count; i++)
657 gpiod_free(lh->descs[i]);
661 put_device(&gdev->dev);
666 * GPIO line event management
670 * struct lineevent_state - contains the state of a userspace event
671 * @gdev: the GPIO device the event pertains to
672 * @label: consumer label used to tag descriptors
673 * @desc: the GPIO descriptor held by this event
674 * @eflags: the event flags this line was requested with
675 * @irq: the interrupt that trigger in response to events on this GPIO
676 * @wait: wait queue that handles blocking reads of events
677 * @events: KFIFO for the GPIO events
678 * @read_lock: mutex lock to protect reads from colliding with adding
679 * new events to the FIFO
680 * @timestamp: cache for the timestamp storing it between hardirq
681 * and IRQ thread, used to bring the timestamp close to the actual
684 struct lineevent_state {
685 struct gpio_device *gdev;
687 struct gpio_desc *desc;
690 wait_queue_head_t wait;
691 DECLARE_KFIFO(events, struct gpioevent_data, 16);
692 struct mutex read_lock;
696 #define GPIOEVENT_REQUEST_VALID_FLAGS \
697 (GPIOEVENT_REQUEST_RISING_EDGE | \
698 GPIOEVENT_REQUEST_FALLING_EDGE)
700 static __poll_t lineevent_poll(struct file *filep,
701 struct poll_table_struct *wait)
703 struct lineevent_state *le = filep->private_data;
706 poll_wait(filep, &le->wait, wait);
708 if (!kfifo_is_empty(&le->events))
709 events = EPOLLIN | EPOLLRDNORM;
715 static ssize_t lineevent_read(struct file *filep,
720 struct lineevent_state *le = filep->private_data;
724 if (count < sizeof(struct gpioevent_data))
728 if (kfifo_is_empty(&le->events)) {
729 if (filep->f_flags & O_NONBLOCK)
732 ret = wait_event_interruptible(le->wait,
733 !kfifo_is_empty(&le->events));
738 if (mutex_lock_interruptible(&le->read_lock))
740 ret = kfifo_to_user(&le->events, buf, count, &copied);
741 mutex_unlock(&le->read_lock);
747 * If we couldn't read anything from the fifo (a different
748 * thread might have been faster) we either return -EAGAIN if
749 * the file descriptor is non-blocking, otherwise we go back to
750 * sleep and wait for more data to arrive.
752 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
755 } while (copied == 0);
760 static int lineevent_release(struct inode *inode, struct file *filep)
762 struct lineevent_state *le = filep->private_data;
763 struct gpio_device *gdev = le->gdev;
765 free_irq(le->irq, le);
766 gpiod_free(le->desc);
769 put_device(&gdev->dev);
773 static long lineevent_ioctl(struct file *filep, unsigned int cmd,
776 struct lineevent_state *le = filep->private_data;
777 void __user *ip = (void __user *)arg;
778 struct gpiohandle_data ghd;
781 * We can get the value for an event line but not set it,
782 * because it is input by definition.
784 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
787 memset(&ghd, 0, sizeof(ghd));
789 val = gpiod_get_value_cansleep(le->desc);
794 if (copy_to_user(ip, &ghd, sizeof(ghd)))
803 static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
806 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
810 static const struct file_operations lineevent_fileops = {
811 .release = lineevent_release,
812 .read = lineevent_read,
813 .poll = lineevent_poll,
814 .owner = THIS_MODULE,
815 .llseek = noop_llseek,
816 .unlocked_ioctl = lineevent_ioctl,
818 .compat_ioctl = lineevent_ioctl_compat,
822 static irqreturn_t lineevent_irq_thread(int irq, void *p)
824 struct lineevent_state *le = p;
825 struct gpioevent_data ge;
828 /* Do not leak kernel stack to userspace */
829 memset(&ge, 0, sizeof(ge));
832 * We may be running from a nested threaded interrupt in which case
833 * we didn't get the timestamp from lineevent_irq_handler().
836 ge.timestamp = ktime_get_real_ns();
838 ge.timestamp = le->timestamp;
840 if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
841 && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
842 int level = gpiod_get_value_cansleep(le->desc);
844 /* Emit low-to-high event */
845 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
847 /* Emit high-to-low event */
848 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
849 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
850 /* Emit low-to-high event */
851 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
852 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
853 /* Emit high-to-low event */
854 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
859 ret = kfifo_put(&le->events, ge);
861 wake_up_poll(&le->wait, EPOLLIN);
866 static irqreturn_t lineevent_irq_handler(int irq, void *p)
868 struct lineevent_state *le = p;
871 * Just store the timestamp in hardirq context so we get it as
872 * close in time as possible to the actual event.
874 le->timestamp = ktime_get_real_ns();
876 return IRQ_WAKE_THREAD;
879 static int lineevent_create(struct gpio_device *gdev, void __user *ip)
881 struct gpioevent_request eventreq;
882 struct lineevent_state *le;
883 struct gpio_desc *desc;
892 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
895 le = kzalloc(sizeof(*le), GFP_KERNEL);
899 get_device(&gdev->dev);
901 /* Make sure this is terminated */
902 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
903 if (strlen(eventreq.consumer_label)) {
904 le->label = kstrdup(eventreq.consumer_label,
912 offset = eventreq.lineoffset;
913 lflags = eventreq.handleflags;
914 eflags = eventreq.eventflags;
916 if (offset >= gdev->ngpio) {
921 /* Return an error if a unknown flag is set */
922 if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
923 (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
928 /* This is just wrong: we don't look for events on output lines */
929 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
934 desc = &gdev->descs[offset];
935 ret = gpiod_request(desc, le->label);
941 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
942 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
943 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
944 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
945 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
946 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
948 ret = gpiod_direction_input(desc);
952 le->irq = gpiod_to_irq(desc);
958 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
959 irqflags |= IRQF_TRIGGER_RISING;
960 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
961 irqflags |= IRQF_TRIGGER_FALLING;
962 irqflags |= IRQF_ONESHOT;
964 INIT_KFIFO(le->events);
965 init_waitqueue_head(&le->wait);
966 mutex_init(&le->read_lock);
968 /* Request a thread to read the events */
969 ret = request_threaded_irq(le->irq,
970 lineevent_irq_handler,
971 lineevent_irq_thread,
978 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
984 file = anon_inode_getfile("gpio-event",
987 O_RDONLY | O_CLOEXEC);
990 goto out_put_unused_fd;
994 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
996 * fput() will trigger the release() callback, so do not go onto
997 * the regular error cleanup path here.
1004 fd_install(fd, file);
1011 free_irq(le->irq, le);
1013 gpiod_free(le->desc);
1018 put_device(&gdev->dev);
1023 * gpio_ioctl() - ioctl handler for the GPIO chardev
1025 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1027 struct gpio_device *gdev = filp->private_data;
1028 struct gpio_chip *chip = gdev->chip;
1029 void __user *ip = (void __user *)arg;
1031 /* We fail any subsequent ioctl():s when the chip is gone */
1035 /* Fill in the struct and pass to userspace */
1036 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
1037 struct gpiochip_info chipinfo;
1039 memset(&chipinfo, 0, sizeof(chipinfo));
1041 strncpy(chipinfo.name, dev_name(&gdev->dev),
1042 sizeof(chipinfo.name));
1043 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
1044 strncpy(chipinfo.label, gdev->label,
1045 sizeof(chipinfo.label));
1046 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
1047 chipinfo.lines = gdev->ngpio;
1048 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
1051 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
1052 struct gpioline_info lineinfo;
1053 struct gpio_desc *desc;
1055 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
1057 if (lineinfo.line_offset >= gdev->ngpio)
1060 desc = &gdev->descs[lineinfo.line_offset];
1062 strncpy(lineinfo.name, desc->name,
1063 sizeof(lineinfo.name));
1064 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
1066 lineinfo.name[0] = '\0';
1069 strncpy(lineinfo.consumer, desc->label,
1070 sizeof(lineinfo.consumer));
1071 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
1073 lineinfo.consumer[0] = '\0';
1077 * Userspace only need to know that the kernel is using
1078 * this GPIO so it can't use it.
1081 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
1082 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
1083 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
1084 test_bit(FLAG_EXPORT, &desc->flags) ||
1085 test_bit(FLAG_SYSFS, &desc->flags))
1086 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
1087 if (test_bit(FLAG_IS_OUT, &desc->flags))
1088 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
1089 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1090 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
1091 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1092 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
1093 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1094 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
1096 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
1099 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
1100 return linehandle_create(gdev, ip);
1101 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
1102 return lineevent_create(gdev, ip);
1107 #ifdef CONFIG_COMPAT
1108 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
1111 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
1116 * gpio_chrdev_open() - open the chardev for ioctl operations
1117 * @inode: inode for this chardev
1118 * @filp: file struct for storing private data
1119 * Returns 0 on success
1121 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
1123 struct gpio_device *gdev = container_of(inode->i_cdev,
1124 struct gpio_device, chrdev);
1126 /* Fail on open if the backing gpiochip is gone */
1129 get_device(&gdev->dev);
1130 filp->private_data = gdev;
1132 return nonseekable_open(inode, filp);
1136 * gpio_chrdev_release() - close chardev after ioctl operations
1137 * @inode: inode for this chardev
1138 * @filp: file struct for storing private data
1139 * Returns 0 on success
1141 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1143 struct gpio_device *gdev = container_of(inode->i_cdev,
1144 struct gpio_device, chrdev);
1146 put_device(&gdev->dev);
1151 static const struct file_operations gpio_fileops = {
1152 .release = gpio_chrdev_release,
1153 .open = gpio_chrdev_open,
1154 .owner = THIS_MODULE,
1155 .llseek = no_llseek,
1156 .unlocked_ioctl = gpio_ioctl,
1157 #ifdef CONFIG_COMPAT
1158 .compat_ioctl = gpio_ioctl_compat,
1162 static void gpiodevice_release(struct device *dev)
1164 struct gpio_device *gdev = dev_get_drvdata(dev);
1166 list_del(&gdev->list);
1167 ida_simple_remove(&gpio_ida, gdev->id);
1168 kfree_const(gdev->label);
1173 static int gpiochip_setup_dev(struct gpio_device *gdev)
1177 cdev_init(&gdev->chrdev, &gpio_fileops);
1178 gdev->chrdev.owner = THIS_MODULE;
1179 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1181 status = cdev_device_add(&gdev->chrdev, &gdev->dev);
1185 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1186 MAJOR(gpio_devt), gdev->id);
1188 status = gpiochip_sysfs_register(gdev);
1190 goto err_remove_device;
1192 /* From this point, the .release() function cleans up gpio_device */
1193 gdev->dev.release = gpiodevice_release;
1194 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1195 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1196 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1201 cdev_device_del(&gdev->chrdev, &gdev->dev);
1205 static void gpiochip_machine_hog(struct gpio_chip *chip, struct gpiod_hog *hog)
1207 struct gpio_desc *desc;
1210 desc = gpiochip_get_desc(chip, hog->chip_hwnum);
1212 pr_err("%s: unable to get GPIO desc: %ld\n",
1213 __func__, PTR_ERR(desc));
1217 if (test_bit(FLAG_IS_HOGGED, &desc->flags))
1220 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
1222 pr_err("%s: unable to hog GPIO line (%s:%u): %d\n",
1223 __func__, chip->label, hog->chip_hwnum, rv);
1226 static void machine_gpiochip_add(struct gpio_chip *chip)
1228 struct gpiod_hog *hog;
1230 mutex_lock(&gpio_machine_hogs_mutex);
1232 list_for_each_entry(hog, &gpio_machine_hogs, list) {
1233 if (!strcmp(chip->label, hog->chip_label))
1234 gpiochip_machine_hog(chip, hog);
1237 mutex_unlock(&gpio_machine_hogs_mutex);
1240 static void gpiochip_setup_devs(void)
1242 struct gpio_device *gdev;
1245 list_for_each_entry(gdev, &gpio_devices, list) {
1246 err = gpiochip_setup_dev(gdev);
1248 pr_err("%s: Failed to initialize gpio device (%d)\n",
1249 dev_name(&gdev->dev), err);
1253 int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
1254 struct lock_class_key *lock_key,
1255 struct lock_class_key *request_key)
1257 unsigned long flags;
1260 int base = chip->base;
1261 struct gpio_device *gdev;
1264 * First: allocate and populate the internal stat container, and
1265 * set up the struct device.
1267 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1270 gdev->dev.bus = &gpio_bus_type;
1272 chip->gpiodev = gdev;
1274 gdev->dev.parent = chip->parent;
1275 gdev->dev.of_node = chip->parent->of_node;
1278 #ifdef CONFIG_OF_GPIO
1279 /* If the gpiochip has an assigned OF node this takes precedence */
1281 gdev->dev.of_node = chip->of_node;
1283 chip->of_node = gdev->dev.of_node;
1286 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1291 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1292 device_initialize(&gdev->dev);
1293 dev_set_drvdata(&gdev->dev, gdev);
1294 if (chip->parent && chip->parent->driver)
1295 gdev->owner = chip->parent->driver->owner;
1296 else if (chip->owner)
1297 /* TODO: remove chip->owner */
1298 gdev->owner = chip->owner;
1300 gdev->owner = THIS_MODULE;
1302 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1308 if (chip->ngpio == 0) {
1309 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1311 goto err_free_descs;
1314 if (chip->ngpio > FASTPATH_NGPIO)
1315 chip_warn(chip, "line cnt %u is greater than fast path cnt %u\n",
1316 chip->ngpio, FASTPATH_NGPIO);
1318 gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
1321 goto err_free_descs;
1324 gdev->ngpio = chip->ngpio;
1327 spin_lock_irqsave(&gpio_lock, flags);
1330 * TODO: this allocates a Linux GPIO number base in the global
1331 * GPIO numberspace for this chip. In the long run we want to
1332 * get *rid* of this numberspace and use only descriptors, but
1333 * it may be a pipe dream. It will not happen before we get rid
1334 * of the sysfs interface anyways.
1337 base = gpiochip_find_base(chip->ngpio);
1340 spin_unlock_irqrestore(&gpio_lock, flags);
1341 goto err_free_label;
1344 * TODO: it should not be necessary to reflect the assigned
1345 * base outside of the GPIO subsystem. Go over drivers and
1346 * see if anyone makes use of this, else drop this and assign
1353 status = gpiodev_add_to_list(gdev);
1355 spin_unlock_irqrestore(&gpio_lock, flags);
1356 goto err_free_label;
1359 spin_unlock_irqrestore(&gpio_lock, flags);
1361 for (i = 0; i < chip->ngpio; i++)
1362 gdev->descs[i].gdev = gdev;
1364 #ifdef CONFIG_PINCTRL
1365 INIT_LIST_HEAD(&gdev->pin_ranges);
1368 status = gpiochip_set_desc_names(chip);
1370 goto err_remove_from_list;
1372 status = gpiochip_irqchip_init_valid_mask(chip);
1374 goto err_remove_from_list;
1376 status = gpiochip_alloc_valid_mask(chip);
1378 goto err_remove_irqchip_mask;
1380 status = gpiochip_add_irqchip(chip, lock_key, request_key);
1382 goto err_free_gpiochip_mask;
1384 status = of_gpiochip_add(chip);
1386 goto err_remove_chip;
1388 status = gpiochip_init_valid_mask(chip);
1390 goto err_remove_of_chip;
1392 for (i = 0; i < chip->ngpio; i++) {
1393 struct gpio_desc *desc = &gdev->descs[i];
1395 if (chip->get_direction && gpiochip_line_is_valid(chip, i))
1396 desc->flags = !chip->get_direction(chip, i) ?
1397 (1 << FLAG_IS_OUT) : 0;
1399 desc->flags = !chip->direction_input ?
1400 (1 << FLAG_IS_OUT) : 0;
1403 acpi_gpiochip_add(chip);
1405 machine_gpiochip_add(chip);
1408 * By first adding the chardev, and then adding the device,
1409 * we get a device node entry in sysfs under
1410 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1411 * coldplug of device nodes and other udev business.
1412 * We can do this only if gpiolib has been initialized.
1413 * Otherwise, defer until later.
1415 if (gpiolib_initialized) {
1416 status = gpiochip_setup_dev(gdev);
1418 goto err_remove_acpi_chip;
1422 err_remove_acpi_chip:
1423 acpi_gpiochip_remove(chip);
1425 gpiochip_free_hogs(chip);
1426 of_gpiochip_remove(chip);
1428 gpiochip_irqchip_remove(chip);
1429 err_free_gpiochip_mask:
1430 gpiochip_free_valid_mask(chip);
1431 err_remove_irqchip_mask:
1432 gpiochip_irqchip_free_valid_mask(chip);
1433 err_remove_from_list:
1434 spin_lock_irqsave(&gpio_lock, flags);
1435 list_del(&gdev->list);
1436 spin_unlock_irqrestore(&gpio_lock, flags);
1438 kfree_const(gdev->label);
1442 ida_simple_remove(&gpio_ida, gdev->id);
1444 /* failures here can mean systems won't boot... */
1445 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1446 gdev->base, gdev->base + gdev->ngpio - 1,
1447 chip->label ? : "generic", status);
1451 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1454 * gpiochip_get_data() - get per-subdriver data for the chip
1458 * The per-subdriver data for the chip.
1460 void *gpiochip_get_data(struct gpio_chip *chip)
1462 return chip->gpiodev->data;
1464 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1467 * gpiochip_remove() - unregister a gpio_chip
1468 * @chip: the chip to unregister
1470 * A gpio_chip with any GPIOs still requested may not be removed.
1472 void gpiochip_remove(struct gpio_chip *chip)
1474 struct gpio_device *gdev = chip->gpiodev;
1475 struct gpio_desc *desc;
1476 unsigned long flags;
1478 bool requested = false;
1480 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1481 gpiochip_sysfs_unregister(gdev);
1482 gpiochip_free_hogs(chip);
1483 /* Numb the device, cancelling all outstanding operations */
1485 gpiochip_irqchip_remove(chip);
1486 acpi_gpiochip_remove(chip);
1487 gpiochip_remove_pin_ranges(chip);
1488 of_gpiochip_remove(chip);
1489 gpiochip_free_valid_mask(chip);
1491 * We accept no more calls into the driver from this point, so
1492 * NULL the driver data pointer
1496 spin_lock_irqsave(&gpio_lock, flags);
1497 for (i = 0; i < gdev->ngpio; i++) {
1498 desc = &gdev->descs[i];
1499 if (test_bit(FLAG_REQUESTED, &desc->flags))
1502 spin_unlock_irqrestore(&gpio_lock, flags);
1505 dev_crit(&gdev->dev,
1506 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1509 * The gpiochip side puts its use of the device to rest here:
1510 * if there are no userspace clients, the chardev and device will
1511 * be removed, else it will be dangling until the last user is
1514 cdev_device_del(&gdev->chrdev, &gdev->dev);
1515 put_device(&gdev->dev);
1517 EXPORT_SYMBOL_GPL(gpiochip_remove);
1519 static void devm_gpio_chip_release(struct device *dev, void *res)
1521 struct gpio_chip *chip = *(struct gpio_chip **)res;
1523 gpiochip_remove(chip);
1527 * devm_gpiochip_add_data() - Resource manager gpiochip_add_data()
1528 * @dev: pointer to the device that gpio_chip belongs to.
1529 * @chip: the chip to register, with chip->base initialized
1530 * @data: driver-private data associated with this chip
1532 * Context: potentially before irqs will work
1534 * The gpio chip automatically be released when the device is unbound.
1537 * A negative errno if the chip can't be registered, such as because the
1538 * chip->base is invalid or already associated with a different chip.
1539 * Otherwise it returns zero as a success code.
1541 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1544 struct gpio_chip **ptr;
1547 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1552 ret = gpiochip_add_data(chip, data);
1559 devres_add(dev, ptr);
1563 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1566 * gpiochip_find() - iterator for locating a specific gpio_chip
1567 * @data: data to pass to match function
1568 * @match: Callback function to check gpio_chip
1570 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1571 * determined by a user supplied @match callback. The callback should return
1572 * 0 if the device doesn't match and non-zero if it does. If the callback is
1573 * non-zero, this function will return to the caller and not iterate over any
1576 struct gpio_chip *gpiochip_find(void *data,
1577 int (*match)(struct gpio_chip *chip,
1580 struct gpio_device *gdev;
1581 struct gpio_chip *chip = NULL;
1582 unsigned long flags;
1584 spin_lock_irqsave(&gpio_lock, flags);
1585 list_for_each_entry(gdev, &gpio_devices, list)
1586 if (gdev->chip && match(gdev->chip, data)) {
1591 spin_unlock_irqrestore(&gpio_lock, flags);
1595 EXPORT_SYMBOL_GPL(gpiochip_find);
1597 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1599 const char *name = data;
1601 return !strcmp(chip->label, name);
1604 static struct gpio_chip *find_chip_by_name(const char *name)
1606 return gpiochip_find((void *)name, gpiochip_match_name);
1609 #ifdef CONFIG_GPIOLIB_IRQCHIP
1612 * The following is irqchip helper code for gpiochips.
1615 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1617 if (!gpiochip->irq.need_valid_mask)
1620 gpiochip->irq.valid_mask = gpiochip_allocate_mask(gpiochip);
1621 if (!gpiochip->irq.valid_mask)
1627 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1629 kfree(gpiochip->irq.valid_mask);
1630 gpiochip->irq.valid_mask = NULL;
1633 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1634 unsigned int offset)
1636 if (!gpiochip_line_is_valid(gpiochip, offset))
1638 /* No mask means all valid */
1639 if (likely(!gpiochip->irq.valid_mask))
1641 return test_bit(offset, gpiochip->irq.valid_mask);
1643 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1646 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1647 * @gpiochip: the gpiochip to set the irqchip chain to
1648 * @parent_irq: the irq number corresponding to the parent IRQ for this
1650 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1651 * coming out of the gpiochip. If the interrupt is nested rather than
1652 * cascaded, pass NULL in this handler argument
1654 static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
1655 unsigned int parent_irq,
1656 irq_flow_handler_t parent_handler)
1658 if (!gpiochip->irq.domain) {
1659 chip_err(gpiochip, "called %s before setting up irqchip\n",
1664 if (parent_handler) {
1665 if (gpiochip->can_sleep) {
1667 "you cannot have chained interrupts on a chip that may sleep\n");
1671 * The parent irqchip is already using the chip_data for this
1672 * irqchip, so our callbacks simply use the handler_data.
1674 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1677 gpiochip->irq.parent_irq = parent_irq;
1678 gpiochip->irq.parents = &gpiochip->irq.parent_irq;
1679 gpiochip->irq.num_parents = 1;
1684 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1685 * @gpiochip: the gpiochip to set the irqchip chain to
1686 * @irqchip: the irqchip to chain to the gpiochip
1687 * @parent_irq: the irq number corresponding to the parent IRQ for this
1689 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1690 * coming out of the gpiochip.
1692 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1693 struct irq_chip *irqchip,
1694 unsigned int parent_irq,
1695 irq_flow_handler_t parent_handler)
1697 if (gpiochip->irq.threaded) {
1698 chip_err(gpiochip, "tried to chain a threaded gpiochip\n");
1702 gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, parent_handler);
1704 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1707 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1708 * @gpiochip: the gpiochip to set the irqchip nested handler to
1709 * @irqchip: the irqchip to nest to the gpiochip
1710 * @parent_irq: the irq number corresponding to the parent IRQ for this
1713 void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1714 struct irq_chip *irqchip,
1715 unsigned int parent_irq)
1717 gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, NULL);
1719 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1722 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1723 * @d: the irqdomain used by this irqchip
1724 * @irq: the global irq number used by this GPIO irqchip irq
1725 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1727 * This function will set up the mapping for a certain IRQ line on a
1728 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1729 * stored inside the gpiochip.
1731 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1732 irq_hw_number_t hwirq)
1734 struct gpio_chip *chip = d->host_data;
1737 if (!gpiochip_irqchip_irq_valid(chip, hwirq))
1740 irq_set_chip_data(irq, chip);
1742 * This lock class tells lockdep that GPIO irqs are in a different
1743 * category than their parents, so it won't report false recursion.
1745 irq_set_lockdep_class(irq, chip->irq.lock_key, chip->irq.request_key);
1746 irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
1747 /* Chips that use nested thread handlers have them marked */
1748 if (chip->irq.threaded)
1749 irq_set_nested_thread(irq, 1);
1750 irq_set_noprobe(irq);
1752 if (chip->irq.num_parents == 1)
1753 err = irq_set_parent(irq, chip->irq.parents[0]);
1754 else if (chip->irq.map)
1755 err = irq_set_parent(irq, chip->irq.map[hwirq]);
1761 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1762 * is passed as default type.
1764 if (chip->irq.default_type != IRQ_TYPE_NONE)
1765 irq_set_irq_type(irq, chip->irq.default_type);
1769 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1771 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1773 struct gpio_chip *chip = d->host_data;
1775 if (chip->irq.threaded)
1776 irq_set_nested_thread(irq, 0);
1777 irq_set_chip_and_handler(irq, NULL, NULL);
1778 irq_set_chip_data(irq, NULL);
1780 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1782 static const struct irq_domain_ops gpiochip_domain_ops = {
1783 .map = gpiochip_irq_map,
1784 .unmap = gpiochip_irq_unmap,
1785 /* Virtually all GPIO irqchips are twocell:ed */
1786 .xlate = irq_domain_xlate_twocell,
1790 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1791 * @domain: The IRQ domain used by this IRQ chip
1792 * @data: Outermost irq_data associated with the IRQ
1793 * @reserve: If set, only reserve an interrupt vector instead of assigning one
1795 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1796 * used as the activate function for the &struct irq_domain_ops. The host_data
1797 * for the IRQ domain must be the &struct gpio_chip.
1799 int gpiochip_irq_domain_activate(struct irq_domain *domain,
1800 struct irq_data *data, bool reserve)
1802 struct gpio_chip *chip = domain->host_data;
1804 return gpiochip_lock_as_irq(chip, data->hwirq);
1806 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
1809 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1810 * @domain: The IRQ domain used by this IRQ chip
1811 * @data: Outermost irq_data associated with the IRQ
1813 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1814 * be used as the deactivate function for the &struct irq_domain_ops. The
1815 * host_data for the IRQ domain must be the &struct gpio_chip.
1817 void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1818 struct irq_data *data)
1820 struct gpio_chip *chip = domain->host_data;
1822 return gpiochip_unlock_as_irq(chip, data->hwirq);
1824 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
1826 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1828 if (!gpiochip_irqchip_irq_valid(chip, offset))
1831 return irq_create_mapping(chip->irq.domain, offset);
1834 static int gpiochip_irq_reqres(struct irq_data *d)
1836 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1838 return gpiochip_reqres_irq(chip, d->hwirq);
1841 static void gpiochip_irq_relres(struct irq_data *d)
1843 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1845 gpiochip_relres_irq(chip, d->hwirq);
1848 static void gpiochip_irq_enable(struct irq_data *d)
1850 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1852 gpiochip_enable_irq(chip, d->hwirq);
1853 if (chip->irq.irq_enable)
1854 chip->irq.irq_enable(d);
1856 chip->irq.chip->irq_unmask(d);
1859 static void gpiochip_irq_disable(struct irq_data *d)
1861 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1863 if (chip->irq.irq_disable)
1864 chip->irq.irq_disable(d);
1866 chip->irq.chip->irq_mask(d);
1867 gpiochip_disable_irq(chip, d->hwirq);
1870 static void gpiochip_set_irq_hooks(struct gpio_chip *gpiochip)
1872 struct irq_chip *irqchip = gpiochip->irq.chip;
1874 if (!irqchip->irq_request_resources &&
1875 !irqchip->irq_release_resources) {
1876 irqchip->irq_request_resources = gpiochip_irq_reqres;
1877 irqchip->irq_release_resources = gpiochip_irq_relres;
1879 if (WARN_ON(gpiochip->irq.irq_enable))
1881 /* Check if the irqchip already has this hook... */
1882 if (irqchip->irq_enable == gpiochip_irq_enable) {
1884 * ...and if so, give a gentle warning that this is bad
1888 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1891 gpiochip->irq.irq_enable = irqchip->irq_enable;
1892 gpiochip->irq.irq_disable = irqchip->irq_disable;
1893 irqchip->irq_enable = gpiochip_irq_enable;
1894 irqchip->irq_disable = gpiochip_irq_disable;
1898 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1899 * @gpiochip: the GPIO chip to add the IRQ chip to
1900 * @lock_key: lockdep class for IRQ lock
1901 * @request_key: lockdep class for IRQ request
1903 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
1904 struct lock_class_key *lock_key,
1905 struct lock_class_key *request_key)
1907 struct irq_chip *irqchip = gpiochip->irq.chip;
1908 const struct irq_domain_ops *ops;
1909 struct device_node *np;
1916 if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {
1917 chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n");
1921 np = gpiochip->gpiodev->dev.of_node;
1922 type = gpiochip->irq.default_type;
1925 * Specifying a default trigger is a terrible idea if DT or ACPI is
1926 * used to configure the interrupts, as you may end up with
1927 * conflicting triggers. Tell the user, and reset to NONE.
1929 if (WARN(np && type != IRQ_TYPE_NONE,
1930 "%s: Ignoring %u default trigger\n", np->full_name, type))
1931 type = IRQ_TYPE_NONE;
1933 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1934 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1935 "Ignoring %u default trigger\n", type);
1936 type = IRQ_TYPE_NONE;
1939 gpiochip->to_irq = gpiochip_to_irq;
1940 gpiochip->irq.default_type = type;
1941 gpiochip->irq.lock_key = lock_key;
1942 gpiochip->irq.request_key = request_key;
1944 if (gpiochip->irq.domain_ops)
1945 ops = gpiochip->irq.domain_ops;
1947 ops = &gpiochip_domain_ops;
1949 gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
1950 gpiochip->irq.first,
1952 if (!gpiochip->irq.domain)
1955 if (gpiochip->irq.parent_handler) {
1956 void *data = gpiochip->irq.parent_handler_data ?: gpiochip;
1958 for (i = 0; i < gpiochip->irq.num_parents; i++) {
1960 * The parent IRQ chip is already using the chip_data
1961 * for this IRQ chip, so our callbacks simply use the
1964 irq_set_chained_handler_and_data(gpiochip->irq.parents[i],
1965 gpiochip->irq.parent_handler,
1970 gpiochip_set_irq_hooks(gpiochip);
1972 acpi_gpiochip_request_interrupts(gpiochip);
1978 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1979 * @gpiochip: the gpiochip to remove the irqchip from
1981 * This is called only from gpiochip_remove()
1983 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1985 struct irq_chip *irqchip = gpiochip->irq.chip;
1986 unsigned int offset;
1988 acpi_gpiochip_free_interrupts(gpiochip);
1990 if (irqchip && gpiochip->irq.parent_handler) {
1991 struct gpio_irq_chip *irq = &gpiochip->irq;
1994 for (i = 0; i < irq->num_parents; i++)
1995 irq_set_chained_handler_and_data(irq->parents[i],
1999 /* Remove all IRQ mappings and delete the domain */
2000 if (gpiochip->irq.domain) {
2003 for (offset = 0; offset < gpiochip->ngpio; offset++) {
2004 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
2007 irq = irq_find_mapping(gpiochip->irq.domain, offset);
2008 irq_dispose_mapping(irq);
2011 irq_domain_remove(gpiochip->irq.domain);
2015 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
2016 irqchip->irq_request_resources = NULL;
2017 irqchip->irq_release_resources = NULL;
2019 if (irqchip->irq_enable == gpiochip_irq_enable) {
2020 irqchip->irq_enable = gpiochip->irq.irq_enable;
2021 irqchip->irq_disable = gpiochip->irq.irq_disable;
2024 gpiochip->irq.irq_enable = NULL;
2025 gpiochip->irq.irq_disable = NULL;
2026 gpiochip->irq.chip = NULL;
2028 gpiochip_irqchip_free_valid_mask(gpiochip);
2032 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
2033 * @gpiochip: the gpiochip to add the irqchip to
2034 * @irqchip: the irqchip to add to the gpiochip
2035 * @first_irq: if not dynamically assigned, the base (first) IRQ to
2036 * allocate gpiochip irqs from
2037 * @handler: the irq handler to use (often a predefined irq core function)
2038 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
2039 * to have the core avoid setting up any default type in the hardware.
2040 * @threaded: whether this irqchip uses a nested thread handler
2041 * @lock_key: lockdep class for IRQ lock
2042 * @request_key: lockdep class for IRQ request
2044 * This function closely associates a certain irqchip with a certain
2045 * gpiochip, providing an irq domain to translate the local IRQs to
2046 * global irqs in the gpiolib core, and making sure that the gpiochip
2047 * is passed as chip data to all related functions. Driver callbacks
2048 * need to use gpiochip_get_data() to get their local state containers back
2049 * from the gpiochip passed as chip data. An irqdomain will be stored
2050 * in the gpiochip that shall be used by the driver to handle IRQ number
2051 * translation. The gpiochip will need to be initialized and registered
2052 * before calling this function.
2054 * This function will handle two cell:ed simple IRQs and assumes all
2055 * the pins on the gpiochip can generate a unique IRQ. Everything else
2056 * need to be open coded.
2058 int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
2059 struct irq_chip *irqchip,
2060 unsigned int first_irq,
2061 irq_flow_handler_t handler,
2064 struct lock_class_key *lock_key,
2065 struct lock_class_key *request_key)
2067 struct device_node *of_node;
2069 if (!gpiochip || !irqchip)
2072 if (!gpiochip->parent) {
2073 pr_err("missing gpiochip .dev parent pointer\n");
2076 gpiochip->irq.threaded = threaded;
2077 of_node = gpiochip->parent->of_node;
2078 #ifdef CONFIG_OF_GPIO
2080 * If the gpiochip has an assigned OF node this takes precedence
2081 * FIXME: get rid of this and use gpiochip->parent->of_node
2084 if (gpiochip->of_node)
2085 of_node = gpiochip->of_node;
2088 * Specifying a default trigger is a terrible idea if DT or ACPI is
2089 * used to configure the interrupts, as you may end-up with
2090 * conflicting triggers. Tell the user, and reset to NONE.
2092 if (WARN(of_node && type != IRQ_TYPE_NONE,
2093 "%pOF: Ignoring %d default trigger\n", of_node, type))
2094 type = IRQ_TYPE_NONE;
2095 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
2096 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
2097 "Ignoring %d default trigger\n", type);
2098 type = IRQ_TYPE_NONE;
2101 gpiochip->irq.chip = irqchip;
2102 gpiochip->irq.handler = handler;
2103 gpiochip->irq.default_type = type;
2104 gpiochip->to_irq = gpiochip_to_irq;
2105 gpiochip->irq.lock_key = lock_key;
2106 gpiochip->irq.request_key = request_key;
2107 gpiochip->irq.domain = irq_domain_add_simple(of_node,
2108 gpiochip->ngpio, first_irq,
2109 &gpiochip_domain_ops, gpiochip);
2110 if (!gpiochip->irq.domain) {
2111 gpiochip->irq.chip = NULL;
2115 gpiochip_set_irq_hooks(gpiochip);
2117 acpi_gpiochip_request_interrupts(gpiochip);
2121 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
2123 #else /* CONFIG_GPIOLIB_IRQCHIP */
2125 static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
2126 struct lock_class_key *lock_key,
2127 struct lock_class_key *request_key)
2132 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
2133 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
2137 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
2140 #endif /* CONFIG_GPIOLIB_IRQCHIP */
2143 * gpiochip_generic_request() - request the gpio function for a pin
2144 * @chip: the gpiochip owning the GPIO
2145 * @offset: the offset of the GPIO to request for GPIO function
2147 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
2149 return pinctrl_gpio_request(chip->gpiodev->base + offset);
2151 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2154 * gpiochip_generic_free() - free the gpio function from a pin
2155 * @chip: the gpiochip to request the gpio function for
2156 * @offset: the offset of the GPIO to free from GPIO function
2158 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
2160 pinctrl_gpio_free(chip->gpiodev->base + offset);
2162 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2165 * gpiochip_generic_config() - apply configuration for a pin
2166 * @chip: the gpiochip owning the GPIO
2167 * @offset: the offset of the GPIO to apply the configuration
2168 * @config: the configuration to be applied
2170 int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
2171 unsigned long config)
2173 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
2175 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2177 #ifdef CONFIG_PINCTRL
2180 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2181 * @chip: the gpiochip to add the range for
2182 * @pctldev: the pin controller to map to
2183 * @gpio_offset: the start offset in the current gpio_chip number space
2184 * @pin_group: name of the pin group inside the pin controller
2186 * Calling this function directly from a DeviceTree-supported
2187 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2188 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2189 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2191 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
2192 struct pinctrl_dev *pctldev,
2193 unsigned int gpio_offset, const char *pin_group)
2195 struct gpio_pin_range *pin_range;
2196 struct gpio_device *gdev = chip->gpiodev;
2199 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2201 chip_err(chip, "failed to allocate pin ranges\n");
2205 /* Use local offset as range ID */
2206 pin_range->range.id = gpio_offset;
2207 pin_range->range.gc = chip;
2208 pin_range->range.name = chip->label;
2209 pin_range->range.base = gdev->base + gpio_offset;
2210 pin_range->pctldev = pctldev;
2212 ret = pinctrl_get_group_pins(pctldev, pin_group,
2213 &pin_range->range.pins,
2214 &pin_range->range.npins);
2220 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2222 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2223 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2224 pinctrl_dev_get_devname(pctldev), pin_group);
2226 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2230 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2233 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2234 * @chip: the gpiochip to add the range for
2235 * @pinctl_name: the dev_name() of the pin controller to map to
2236 * @gpio_offset: the start offset in the current gpio_chip number space
2237 * @pin_offset: the start offset in the pin controller number space
2238 * @npins: the number of pins from the offset of each pin space (GPIO and
2239 * pin controller) to accumulate in this range
2242 * 0 on success, or a negative error-code on failure.
2244 * Calling this function directly from a DeviceTree-supported
2245 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2246 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2247 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2249 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
2250 unsigned int gpio_offset, unsigned int pin_offset,
2253 struct gpio_pin_range *pin_range;
2254 struct gpio_device *gdev = chip->gpiodev;
2257 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2259 chip_err(chip, "failed to allocate pin ranges\n");
2263 /* Use local offset as range ID */
2264 pin_range->range.id = gpio_offset;
2265 pin_range->range.gc = chip;
2266 pin_range->range.name = chip->label;
2267 pin_range->range.base = gdev->base + gpio_offset;
2268 pin_range->range.pin_base = pin_offset;
2269 pin_range->range.npins = npins;
2270 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2272 if (IS_ERR(pin_range->pctldev)) {
2273 ret = PTR_ERR(pin_range->pctldev);
2274 chip_err(chip, "could not create pin range\n");
2278 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2279 gpio_offset, gpio_offset + npins - 1,
2281 pin_offset, pin_offset + npins - 1);
2283 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2287 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2290 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2291 * @chip: the chip to remove all the mappings for
2293 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
2295 struct gpio_pin_range *pin_range, *tmp;
2296 struct gpio_device *gdev = chip->gpiodev;
2298 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2299 list_del(&pin_range->node);
2300 pinctrl_remove_gpio_range(pin_range->pctldev,
2305 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2307 #endif /* CONFIG_PINCTRL */
2309 /* These "optional" allocation calls help prevent drivers from stomping
2310 * on each other, and help provide better diagnostics in debugfs.
2311 * They're called even less than the "set direction" calls.
2313 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2315 struct gpio_chip *chip = desc->gdev->chip;
2317 unsigned long flags;
2321 label = kstrdup_const(label, GFP_KERNEL);
2326 spin_lock_irqsave(&gpio_lock, flags);
2328 /* NOTE: gpio_request() can be called in early boot,
2329 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2332 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2333 desc_set_label(desc, label ? : "?");
2341 if (chip->request) {
2342 /* chip->request may sleep */
2343 spin_unlock_irqrestore(&gpio_lock, flags);
2344 offset = gpio_chip_hwgpio(desc);
2345 if (gpiochip_line_is_valid(chip, offset))
2346 status = chip->request(chip, offset);
2349 spin_lock_irqsave(&gpio_lock, flags);
2352 desc_set_label(desc, NULL);
2354 clear_bit(FLAG_REQUESTED, &desc->flags);
2358 if (chip->get_direction) {
2359 /* chip->get_direction may sleep */
2360 spin_unlock_irqrestore(&gpio_lock, flags);
2361 gpiod_get_direction(desc);
2362 spin_lock_irqsave(&gpio_lock, flags);
2365 spin_unlock_irqrestore(&gpio_lock, flags);
2370 * This descriptor validation needs to be inserted verbatim into each
2371 * function taking a descriptor, so we need to use a preprocessor
2372 * macro to avoid endless duplication. If the desc is NULL it is an
2373 * optional GPIO and calls should just bail out.
2375 static int validate_desc(const struct gpio_desc *desc, const char *func)
2380 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2381 return PTR_ERR(desc);
2384 pr_warn("%s: invalid GPIO (no device)\n", func);
2387 if (!desc->gdev->chip) {
2388 dev_warn(&desc->gdev->dev,
2389 "%s: backing chip is gone\n", func);
2395 #define VALIDATE_DESC(desc) do { \
2396 int __valid = validate_desc(desc, __func__); \
2401 #define VALIDATE_DESC_VOID(desc) do { \
2402 int __valid = validate_desc(desc, __func__); \
2407 int gpiod_request(struct gpio_desc *desc, const char *label)
2409 int status = -EPROBE_DEFER;
2410 struct gpio_device *gdev;
2412 VALIDATE_DESC(desc);
2415 if (try_module_get(gdev->owner)) {
2416 status = gpiod_request_commit(desc, label);
2418 module_put(gdev->owner);
2420 get_device(&gdev->dev);
2424 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2429 static bool gpiod_free_commit(struct gpio_desc *desc)
2432 unsigned long flags;
2433 struct gpio_chip *chip;
2437 gpiod_unexport(desc);
2439 spin_lock_irqsave(&gpio_lock, flags);
2441 chip = desc->gdev->chip;
2442 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2444 spin_unlock_irqrestore(&gpio_lock, flags);
2445 might_sleep_if(chip->can_sleep);
2446 chip->free(chip, gpio_chip_hwgpio(desc));
2447 spin_lock_irqsave(&gpio_lock, flags);
2449 kfree_const(desc->label);
2450 desc_set_label(desc, NULL);
2451 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2452 clear_bit(FLAG_REQUESTED, &desc->flags);
2453 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2454 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2455 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2459 spin_unlock_irqrestore(&gpio_lock, flags);
2463 void gpiod_free(struct gpio_desc *desc)
2465 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2466 module_put(desc->gdev->owner);
2467 put_device(&desc->gdev->dev);
2469 WARN_ON(extra_checks);
2474 * gpiochip_is_requested - return string iff signal was requested
2475 * @chip: controller managing the signal
2476 * @offset: of signal within controller's 0..(ngpio - 1) range
2478 * Returns NULL if the GPIO is not currently requested, else a string.
2479 * The string returned is the label passed to gpio_request(); if none has been
2480 * passed it is a meaningless, non-NULL constant.
2482 * This function is for use by GPIO controller drivers. The label can
2483 * help with diagnostics, and knowing that the signal is used as a GPIO
2484 * can help avoid accidentally multiplexing it to another controller.
2486 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2488 struct gpio_desc *desc;
2490 if (offset >= chip->ngpio)
2493 desc = &chip->gpiodev->descs[offset];
2495 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2499 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2502 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2504 * @hwnum: hardware number of the GPIO for which to request the descriptor
2505 * @label: label for the GPIO
2506 * @flags: flags for this GPIO or 0 if default
2508 * Function allows GPIO chip drivers to request and use their own GPIO
2509 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2510 * function will not increase reference count of the GPIO chip module. This
2511 * allows the GPIO chip module to be unloaded as needed (we assume that the
2512 * GPIO chip driver handles freeing the GPIOs it has requested).
2515 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2518 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2520 enum gpiod_flags flags)
2522 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2526 chip_err(chip, "failed to get GPIO descriptor\n");
2530 err = gpiod_request_commit(desc, label);
2532 return ERR_PTR(err);
2534 err = gpiod_configure_flags(desc, label, 0, flags);
2536 chip_err(chip, "setup of own GPIO %s failed\n", label);
2537 gpiod_free_commit(desc);
2538 return ERR_PTR(err);
2543 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2546 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2547 * @desc: GPIO descriptor to free
2549 * Function frees the given GPIO requested previously with
2550 * gpiochip_request_own_desc().
2552 void gpiochip_free_own_desc(struct gpio_desc *desc)
2555 gpiod_free_commit(desc);
2557 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2560 * Drivers MUST set GPIO direction before making get/set calls. In
2561 * some cases this is done in early boot, before IRQs are enabled.
2563 * As a rule these aren't called more than once (except for drivers
2564 * using the open-drain emulation idiom) so these are natural places
2565 * to accumulate extra debugging checks. Note that we can't (yet)
2566 * rely on gpio_request() having been called beforehand.
2569 static int gpio_set_config(struct gpio_chip *gc, unsigned offset,
2570 enum pin_config_param mode)
2572 unsigned long config = { PIN_CONF_PACKED(mode, 0) };
2574 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2578 * gpiod_direction_input - set the GPIO direction to input
2579 * @desc: GPIO to set to input
2581 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2582 * be called safely on it.
2584 * Return 0 in case of success, else an error code.
2586 int gpiod_direction_input(struct gpio_desc *desc)
2588 struct gpio_chip *chip;
2591 VALIDATE_DESC(desc);
2592 chip = desc->gdev->chip;
2595 * It is legal to have no .get() and .direction_input() specified if
2596 * the chip is output-only, but you can't specify .direction_input()
2597 * and not support the .get() operation, that doesn't make sense.
2599 if (!chip->get && chip->direction_input) {
2601 "%s: missing get() but have direction_input()\n",
2607 * If we have a .direction_input() callback, things are simple,
2608 * just call it. Else we are some input-only chip so try to check the
2609 * direction (if .get_direction() is supported) else we silently
2610 * assume we are in input mode after this.
2612 if (chip->direction_input) {
2613 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2614 } else if (chip->get_direction &&
2615 (chip->get_direction(chip, gpio_chip_hwgpio(desc)) != 1)) {
2617 "%s: missing direction_input() operation and line is output\n",
2622 clear_bit(FLAG_IS_OUT, &desc->flags);
2624 if (test_bit(FLAG_PULL_UP, &desc->flags))
2625 gpio_set_config(chip, gpio_chip_hwgpio(desc),
2626 PIN_CONFIG_BIAS_PULL_UP);
2627 else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
2628 gpio_set_config(chip, gpio_chip_hwgpio(desc),
2629 PIN_CONFIG_BIAS_PULL_DOWN);
2631 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2635 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2637 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2639 struct gpio_chip *gc = desc->gdev->chip;
2644 * It's OK not to specify .direction_output() if the gpiochip is
2645 * output-only, but if there is then not even a .set() operation it
2646 * is pretty tricky to drive the output line.
2648 if (!gc->set && !gc->direction_output) {
2650 "%s: missing set() and direction_output() operations\n",
2655 if (gc->direction_output) {
2656 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2658 /* Check that we are in output mode if we can */
2659 if (gc->get_direction &&
2660 gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
2662 "%s: missing direction_output() operation\n",
2667 * If we can't actively set the direction, we are some
2668 * output-only chip, so just drive the output as desired.
2670 gc->set(gc, gpio_chip_hwgpio(desc), val);
2674 set_bit(FLAG_IS_OUT, &desc->flags);
2675 trace_gpio_value(desc_to_gpio(desc), 0, val);
2676 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2681 * gpiod_direction_output_raw - set the GPIO direction to output
2682 * @desc: GPIO to set to output
2683 * @value: initial output value of the GPIO
2685 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2686 * be called safely on it. The initial value of the output must be specified
2687 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2689 * Return 0 in case of success, else an error code.
2691 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2693 VALIDATE_DESC(desc);
2694 return gpiod_direction_output_raw_commit(desc, value);
2696 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2699 * gpiod_direction_output - set the GPIO direction to output
2700 * @desc: GPIO to set to output
2701 * @value: initial output value of the GPIO
2703 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2704 * be called safely on it. The initial value of the output must be specified
2705 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2708 * Return 0 in case of success, else an error code.
2710 int gpiod_direction_output(struct gpio_desc *desc, int value)
2712 struct gpio_chip *gc;
2715 VALIDATE_DESC(desc);
2716 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2721 /* GPIOs used for enabled IRQs shall not be set as output */
2722 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
2723 test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
2725 "%s: tried to set a GPIO tied to an IRQ as output\n",
2730 gc = desc->gdev->chip;
2731 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2732 /* First see if we can enable open drain in hardware */
2733 ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
2734 PIN_CONFIG_DRIVE_OPEN_DRAIN);
2736 goto set_output_value;
2737 /* Emulate open drain by not actively driving the line high */
2739 return gpiod_direction_input(desc);
2741 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2742 ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
2743 PIN_CONFIG_DRIVE_OPEN_SOURCE);
2745 goto set_output_value;
2746 /* Emulate open source by not actively driving the line low */
2748 return gpiod_direction_input(desc);
2750 gpio_set_config(gc, gpio_chip_hwgpio(desc),
2751 PIN_CONFIG_DRIVE_PUSH_PULL);
2755 return gpiod_direction_output_raw_commit(desc, value);
2757 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2760 * gpiod_set_debounce - sets @debounce time for a GPIO
2761 * @desc: descriptor of the GPIO for which to set debounce time
2762 * @debounce: debounce time in microseconds
2765 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2768 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2770 struct gpio_chip *chip;
2771 unsigned long config;
2773 VALIDATE_DESC(desc);
2774 chip = desc->gdev->chip;
2775 if (!chip->set || !chip->set_config) {
2777 "%s: missing set() or set_config() operations\n",
2782 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2783 return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
2785 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2788 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2789 * @desc: descriptor of the GPIO for which to configure persistence
2790 * @transitory: True to lose state on suspend or reset, false for persistence
2793 * 0 on success, otherwise a negative error code.
2795 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2797 struct gpio_chip *chip;
2798 unsigned long packed;
2802 VALIDATE_DESC(desc);
2804 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2805 * persistence state.
2808 set_bit(FLAG_TRANSITORY, &desc->flags);
2810 clear_bit(FLAG_TRANSITORY, &desc->flags);
2812 /* If the driver supports it, set the persistence state now */
2813 chip = desc->gdev->chip;
2814 if (!chip->set_config)
2817 packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
2819 gpio = gpio_chip_hwgpio(desc);
2820 rc = chip->set_config(chip, gpio, packed);
2821 if (rc == -ENOTSUPP) {
2822 dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
2829 EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2832 * gpiod_is_active_low - test whether a GPIO is active-low or not
2833 * @desc: the gpio descriptor to test
2835 * Returns 1 if the GPIO is active-low, 0 otherwise.
2837 int gpiod_is_active_low(const struct gpio_desc *desc)
2839 VALIDATE_DESC(desc);
2840 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2842 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2844 /* I/O calls are only valid after configuration completed; the relevant
2845 * "is this a valid GPIO" error checks should already have been done.
2847 * "Get" operations are often inlinable as reading a pin value register,
2848 * and masking the relevant bit in that register.
2850 * When "set" operations are inlinable, they involve writing that mask to
2851 * one register to set a low value, or a different register to set it high.
2852 * Otherwise locking is needed, so there may be little value to inlining.
2854 *------------------------------------------------------------------------
2856 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2857 * have requested the GPIO. That can include implicit requesting by
2858 * a direction setting call. Marking a gpio as requested locks its chip
2859 * in memory, guaranteeing that these table lookups need no more locking
2860 * and that gpiochip_remove() will fail.
2862 * REVISIT when debugging, consider adding some instrumentation to ensure
2863 * that the GPIO was actually requested.
2866 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2868 struct gpio_chip *chip;
2872 chip = desc->gdev->chip;
2873 offset = gpio_chip_hwgpio(desc);
2874 value = chip->get ? chip->get(chip, offset) : -EIO;
2875 value = value < 0 ? value : !!value;
2876 trace_gpio_value(desc_to_gpio(desc), 1, value);
2880 static int gpio_chip_get_multiple(struct gpio_chip *chip,
2881 unsigned long *mask, unsigned long *bits)
2883 if (chip->get_multiple) {
2884 return chip->get_multiple(chip, mask, bits);
2885 } else if (chip->get) {
2888 for_each_set_bit(i, mask, chip->ngpio) {
2889 value = chip->get(chip, i);
2892 __assign_bit(i, bits, value);
2899 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2900 unsigned int array_size,
2901 struct gpio_desc **desc_array,
2902 struct gpio_array *array_info,
2903 unsigned long *value_bitmap)
2908 * Validate array_info against desc_array and its size.
2909 * It should immediately follow desc_array if both
2910 * have been obtained from the same gpiod_get_array() call.
2912 if (array_info && array_info->desc == desc_array &&
2913 array_size <= array_info->size &&
2914 (void *)array_info == desc_array + array_info->size) {
2916 WARN_ON(array_info->chip->can_sleep);
2918 err = gpio_chip_get_multiple(array_info->chip,
2919 array_info->get_mask,
2924 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2925 bitmap_xor(value_bitmap, value_bitmap,
2926 array_info->invert_mask, array_size);
2928 if (bitmap_full(array_info->get_mask, array_size))
2931 i = find_first_zero_bit(array_info->get_mask, array_size);
2936 while (i < array_size) {
2937 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2938 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
2939 unsigned long *mask, *bits;
2942 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
2945 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
2947 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
2952 bits = mask + BITS_TO_LONGS(chip->ngpio);
2953 bitmap_zero(mask, chip->ngpio);
2956 WARN_ON(chip->can_sleep);
2958 /* collect all inputs belonging to the same chip */
2961 const struct gpio_desc *desc = desc_array[i];
2962 int hwgpio = gpio_chip_hwgpio(desc);
2964 __set_bit(hwgpio, mask);
2968 i = find_next_zero_bit(array_info->get_mask,
2970 } while ((i < array_size) &&
2971 (desc_array[i]->gdev->chip == chip));
2973 ret = gpio_chip_get_multiple(chip, mask, bits);
2975 if (mask != fastpath)
2980 for (j = first; j < i; ) {
2981 const struct gpio_desc *desc = desc_array[j];
2982 int hwgpio = gpio_chip_hwgpio(desc);
2983 int value = test_bit(hwgpio, bits);
2985 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2987 __assign_bit(j, value_bitmap, value);
2988 trace_gpio_value(desc_to_gpio(desc), 1, value);
2992 j = find_next_zero_bit(array_info->get_mask, i,
2996 if (mask != fastpath)
3003 * gpiod_get_raw_value() - return a gpio's raw value
3004 * @desc: gpio whose value will be returned
3006 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3007 * its ACTIVE_LOW status, or negative errno on failure.
3009 * This function should be called from contexts where we cannot sleep, and will
3010 * complain if the GPIO chip functions potentially sleep.
3012 int gpiod_get_raw_value(const struct gpio_desc *desc)
3014 VALIDATE_DESC(desc);
3015 /* Should be using gpio_get_value_cansleep() */
3016 WARN_ON(desc->gdev->chip->can_sleep);
3017 return gpiod_get_raw_value_commit(desc);
3019 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
3022 * gpiod_get_value() - return a gpio's value
3023 * @desc: gpio whose value will be returned
3025 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3026 * account, or negative errno on failure.
3028 * This function should be called from contexts where we cannot sleep, and will
3029 * complain if the GPIO chip functions potentially sleep.
3031 int gpiod_get_value(const struct gpio_desc *desc)
3035 VALIDATE_DESC(desc);
3036 /* Should be using gpio_get_value_cansleep() */
3037 WARN_ON(desc->gdev->chip->can_sleep);
3039 value = gpiod_get_raw_value_commit(desc);
3043 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3048 EXPORT_SYMBOL_GPL(gpiod_get_value);
3051 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
3052 * @array_size: number of elements in the descriptor array / value bitmap
3053 * @desc_array: array of GPIO descriptors whose values will be read
3054 * @array_info: information on applicability of fast bitmap processing path
3055 * @value_bitmap: bitmap to store the read values
3057 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3058 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3059 * else an error code.
3061 * This function should be called from contexts where we cannot sleep,
3062 * and it will complain if the GPIO chip functions potentially sleep.
3064 int gpiod_get_raw_array_value(unsigned int array_size,
3065 struct gpio_desc **desc_array,
3066 struct gpio_array *array_info,
3067 unsigned long *value_bitmap)
3071 return gpiod_get_array_value_complex(true, false, array_size,
3072 desc_array, array_info,
3075 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
3078 * gpiod_get_array_value() - read values from an array of GPIOs
3079 * @array_size: number of elements in the descriptor array / value bitmap
3080 * @desc_array: array of GPIO descriptors whose values will be read
3081 * @array_info: information on applicability of fast bitmap processing path
3082 * @value_bitmap: bitmap to store the read values
3084 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3085 * into account. Return 0 in case of success, else an error code.
3087 * This function should be called from contexts where we cannot sleep,
3088 * and it will complain if the GPIO chip functions potentially sleep.
3090 int gpiod_get_array_value(unsigned int array_size,
3091 struct gpio_desc **desc_array,
3092 struct gpio_array *array_info,
3093 unsigned long *value_bitmap)
3097 return gpiod_get_array_value_complex(false, false, array_size,
3098 desc_array, array_info,
3101 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
3104 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
3105 * @desc: gpio descriptor whose state need to be set.
3106 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3108 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
3111 struct gpio_chip *chip = desc->gdev->chip;
3112 int offset = gpio_chip_hwgpio(desc);
3115 err = chip->direction_input(chip, offset);
3117 clear_bit(FLAG_IS_OUT, &desc->flags);
3119 err = chip->direction_output(chip, offset, 0);
3121 set_bit(FLAG_IS_OUT, &desc->flags);
3123 trace_gpio_direction(desc_to_gpio(desc), value, err);
3126 "%s: Error in set_value for open drain err %d\n",
3131 * _gpio_set_open_source_value() - Set the open source gpio's value.
3132 * @desc: gpio descriptor whose state need to be set.
3133 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3135 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
3138 struct gpio_chip *chip = desc->gdev->chip;
3139 int offset = gpio_chip_hwgpio(desc);
3142 err = chip->direction_output(chip, offset, 1);
3144 set_bit(FLAG_IS_OUT, &desc->flags);
3146 err = chip->direction_input(chip, offset);
3148 clear_bit(FLAG_IS_OUT, &desc->flags);
3150 trace_gpio_direction(desc_to_gpio(desc), !value, err);
3153 "%s: Error in set_value for open source err %d\n",
3157 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
3159 struct gpio_chip *chip;
3161 chip = desc->gdev->chip;
3162 trace_gpio_value(desc_to_gpio(desc), 0, value);
3163 chip->set(chip, gpio_chip_hwgpio(desc), value);
3167 * set multiple outputs on the same chip;
3168 * use the chip's set_multiple function if available;
3169 * otherwise set the outputs sequentially;
3170 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3171 * defines which outputs are to be changed
3172 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3173 * defines the values the outputs specified by mask are to be set to
3175 static void gpio_chip_set_multiple(struct gpio_chip *chip,
3176 unsigned long *mask, unsigned long *bits)
3178 if (chip->set_multiple) {
3179 chip->set_multiple(chip, mask, bits);
3183 /* set outputs if the corresponding mask bit is set */
3184 for_each_set_bit(i, mask, chip->ngpio)
3185 chip->set(chip, i, test_bit(i, bits));
3189 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3190 unsigned int array_size,
3191 struct gpio_desc **desc_array,
3192 struct gpio_array *array_info,
3193 unsigned long *value_bitmap)
3198 * Validate array_info against desc_array and its size.
3199 * It should immediately follow desc_array if both
3200 * have been obtained from the same gpiod_get_array() call.
3202 if (array_info && array_info->desc == desc_array &&
3203 array_size <= array_info->size &&
3204 (void *)array_info == desc_array + array_info->size) {
3206 WARN_ON(array_info->chip->can_sleep);
3208 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3209 bitmap_xor(value_bitmap, value_bitmap,
3210 array_info->invert_mask, array_size);
3212 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
3215 if (bitmap_full(array_info->set_mask, array_size))
3218 i = find_first_zero_bit(array_info->set_mask, array_size);
3223 while (i < array_size) {
3224 struct gpio_chip *chip = desc_array[i]->gdev->chip;
3225 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
3226 unsigned long *mask, *bits;
3229 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
3232 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
3234 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
3239 bits = mask + BITS_TO_LONGS(chip->ngpio);
3240 bitmap_zero(mask, chip->ngpio);
3243 WARN_ON(chip->can_sleep);
3246 struct gpio_desc *desc = desc_array[i];
3247 int hwgpio = gpio_chip_hwgpio(desc);
3248 int value = test_bit(i, value_bitmap);
3251 * Pins applicable for fast input but not for
3252 * fast output processing may have been already
3253 * inverted inside the fast path, skip them.
3255 if (!raw && !(array_info &&
3256 test_bit(i, array_info->invert_mask)) &&
3257 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3259 trace_gpio_value(desc_to_gpio(desc), 0, value);
3261 * collect all normal outputs belonging to the same chip
3262 * open drain and open source outputs are set individually
3264 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3265 gpio_set_open_drain_value_commit(desc, value);
3266 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3267 gpio_set_open_source_value_commit(desc, value);
3269 __set_bit(hwgpio, mask);
3271 __set_bit(hwgpio, bits);
3273 __clear_bit(hwgpio, bits);
3279 i = find_next_zero_bit(array_info->set_mask,
3281 } while ((i < array_size) &&
3282 (desc_array[i]->gdev->chip == chip));
3283 /* push collected bits to outputs */
3285 gpio_chip_set_multiple(chip, mask, bits);
3287 if (mask != fastpath)
3294 * gpiod_set_raw_value() - assign a gpio's raw value
3295 * @desc: gpio whose value will be assigned
3296 * @value: value to assign
3298 * Set the raw value of the GPIO, i.e. the value of its physical line without
3299 * regard for its ACTIVE_LOW status.
3301 * This function should be called from contexts where we cannot sleep, and will
3302 * complain if the GPIO chip functions potentially sleep.
3304 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3306 VALIDATE_DESC_VOID(desc);
3307 /* Should be using gpiod_set_value_cansleep() */
3308 WARN_ON(desc->gdev->chip->can_sleep);
3309 gpiod_set_raw_value_commit(desc, value);
3311 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3314 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3315 * @desc: the descriptor to set the value on
3316 * @value: value to set
3318 * This sets the value of a GPIO line backing a descriptor, applying
3319 * different semantic quirks like active low and open drain/source
3322 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3324 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3326 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3327 gpio_set_open_drain_value_commit(desc, value);
3328 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3329 gpio_set_open_source_value_commit(desc, value);
3331 gpiod_set_raw_value_commit(desc, value);
3335 * gpiod_set_value() - assign a gpio's value
3336 * @desc: gpio whose value will be assigned
3337 * @value: value to assign
3339 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3340 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3342 * This function should be called from contexts where we cannot sleep, and will
3343 * complain if the GPIO chip functions potentially sleep.
3345 void gpiod_set_value(struct gpio_desc *desc, int value)
3347 VALIDATE_DESC_VOID(desc);
3348 WARN_ON(desc->gdev->chip->can_sleep);
3349 gpiod_set_value_nocheck(desc, value);
3351 EXPORT_SYMBOL_GPL(gpiod_set_value);
3354 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3355 * @array_size: number of elements in the descriptor array / value bitmap
3356 * @desc_array: array of GPIO descriptors whose values will be assigned
3357 * @array_info: information on applicability of fast bitmap processing path
3358 * @value_bitmap: bitmap of values to assign
3360 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3361 * without regard for their ACTIVE_LOW status.
3363 * This function should be called from contexts where we cannot sleep, and will
3364 * complain if the GPIO chip functions potentially sleep.
3366 int gpiod_set_raw_array_value(unsigned int array_size,
3367 struct gpio_desc **desc_array,
3368 struct gpio_array *array_info,
3369 unsigned long *value_bitmap)
3373 return gpiod_set_array_value_complex(true, false, array_size,
3374 desc_array, array_info, value_bitmap);
3376 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3379 * gpiod_set_array_value() - assign values to an array of GPIOs
3380 * @array_size: number of elements in the descriptor array / value bitmap
3381 * @desc_array: array of GPIO descriptors whose values will be assigned
3382 * @array_info: information on applicability of fast bitmap processing path
3383 * @value_bitmap: bitmap of values to assign
3385 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3388 * This function should be called from contexts where we cannot sleep, and will
3389 * complain if the GPIO chip functions potentially sleep.
3391 int gpiod_set_array_value(unsigned int array_size,
3392 struct gpio_desc **desc_array,
3393 struct gpio_array *array_info,
3394 unsigned long *value_bitmap)
3398 return gpiod_set_array_value_complex(false, false, array_size,
3399 desc_array, array_info,
3402 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3405 * gpiod_cansleep() - report whether gpio value access may sleep
3406 * @desc: gpio to check
3409 int gpiod_cansleep(const struct gpio_desc *desc)
3411 VALIDATE_DESC(desc);
3412 return desc->gdev->chip->can_sleep;
3414 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3417 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3418 * @desc: gpio to set the consumer name on
3419 * @name: the new consumer name
3421 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3423 VALIDATE_DESC(desc);
3425 name = kstrdup_const(name, GFP_KERNEL);
3430 kfree_const(desc->label);
3431 desc_set_label(desc, name);
3435 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3438 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3439 * @desc: gpio whose IRQ will be returned (already requested)
3441 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3444 int gpiod_to_irq(const struct gpio_desc *desc)
3446 struct gpio_chip *chip;
3450 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3451 * requires this function to not return zero on an invalid descriptor
3452 * but rather a negative error number.
3454 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3457 chip = desc->gdev->chip;
3458 offset = gpio_chip_hwgpio(desc);
3460 int retirq = chip->to_irq(chip, offset);
3462 /* Zero means NO_IRQ */
3470 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3473 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3474 * @chip: the chip the GPIO to lock belongs to
3475 * @offset: the offset of the GPIO to lock as IRQ
3477 * This is used directly by GPIO drivers that want to lock down
3478 * a certain GPIO line to be used for IRQs.
3480 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
3482 struct gpio_desc *desc;
3484 desc = gpiochip_get_desc(chip, offset);
3486 return PTR_ERR(desc);
3489 * If it's fast: flush the direction setting if something changed
3492 if (!chip->can_sleep && chip->get_direction) {
3493 int dir = gpiod_get_direction(desc);
3496 chip_err(chip, "%s: cannot get GPIO direction\n",
3502 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
3504 "%s: tried to flag a GPIO set as output for IRQ\n",
3509 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3510 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3513 * If the consumer has not set up a label (such as when the
3514 * IRQ is referenced from .to_irq()) we set up a label here
3515 * so it is clear this is used as an interrupt.
3518 desc_set_label(desc, "interrupt");
3522 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3525 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3526 * @chip: the chip the GPIO to lock belongs to
3527 * @offset: the offset of the GPIO to lock as IRQ
3529 * This is used directly by GPIO drivers that want to indicate
3530 * that a certain GPIO is no longer used exclusively for IRQ.
3532 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
3534 struct gpio_desc *desc;
3536 desc = gpiochip_get_desc(chip, offset);
3540 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3541 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3543 /* If we only had this marking, erase it */
3544 if (desc->label && !strcmp(desc->label, "interrupt"))
3545 desc_set_label(desc, NULL);
3547 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3549 void gpiochip_disable_irq(struct gpio_chip *chip, unsigned int offset)
3551 struct gpio_desc *desc = gpiochip_get_desc(chip, offset);
3553 if (!IS_ERR(desc) &&
3554 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3555 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3557 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3559 void gpiochip_enable_irq(struct gpio_chip *chip, unsigned int offset)
3561 struct gpio_desc *desc = gpiochip_get_desc(chip, offset);
3563 if (!IS_ERR(desc) &&
3564 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3565 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags));
3566 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3569 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3571 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
3573 if (offset >= chip->ngpio)
3576 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
3578 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3580 int gpiochip_reqres_irq(struct gpio_chip *chip, unsigned int offset)
3584 if (!try_module_get(chip->gpiodev->owner))
3587 ret = gpiochip_lock_as_irq(chip, offset);
3589 chip_err(chip, "unable to lock HW IRQ %u for IRQ\n", offset);
3590 module_put(chip->gpiodev->owner);
3595 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3597 void gpiochip_relres_irq(struct gpio_chip *chip, unsigned int offset)
3599 gpiochip_unlock_as_irq(chip, offset);
3600 module_put(chip->gpiodev->owner);
3602 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3604 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
3606 if (offset >= chip->ngpio)
3609 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
3611 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3613 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
3615 if (offset >= chip->ngpio)
3618 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
3620 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3622 bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
3624 if (offset >= chip->ngpio)
3627 return !test_bit(FLAG_TRANSITORY, &chip->gpiodev->descs[offset].flags);
3629 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3632 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3633 * @desc: gpio whose value will be returned
3635 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3636 * its ACTIVE_LOW status, or negative errno on failure.
3638 * This function is to be called from contexts that can sleep.
3640 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3642 might_sleep_if(extra_checks);
3643 VALIDATE_DESC(desc);
3644 return gpiod_get_raw_value_commit(desc);
3646 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3649 * gpiod_get_value_cansleep() - return a gpio's value
3650 * @desc: gpio whose value will be returned
3652 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3653 * account, or negative errno on failure.
3655 * This function is to be called from contexts that can sleep.
3657 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3661 might_sleep_if(extra_checks);
3662 VALIDATE_DESC(desc);
3663 value = gpiod_get_raw_value_commit(desc);
3667 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3672 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3675 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3676 * @array_size: number of elements in the descriptor array / value bitmap
3677 * @desc_array: array of GPIO descriptors whose values will be read
3678 * @array_info: information on applicability of fast bitmap processing path
3679 * @value_bitmap: bitmap to store the read values
3681 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3682 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3683 * else an error code.
3685 * This function is to be called from contexts that can sleep.
3687 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3688 struct gpio_desc **desc_array,
3689 struct gpio_array *array_info,
3690 unsigned long *value_bitmap)
3692 might_sleep_if(extra_checks);
3695 return gpiod_get_array_value_complex(true, true, array_size,
3696 desc_array, array_info,
3699 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3702 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3703 * @array_size: number of elements in the descriptor array / value bitmap
3704 * @desc_array: array of GPIO descriptors whose values will be read
3705 * @array_info: information on applicability of fast bitmap processing path
3706 * @value_bitmap: bitmap to store the read values
3708 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3709 * into account. Return 0 in case of success, else an error code.
3711 * This function is to be called from contexts that can sleep.
3713 int gpiod_get_array_value_cansleep(unsigned int array_size,
3714 struct gpio_desc **desc_array,
3715 struct gpio_array *array_info,
3716 unsigned long *value_bitmap)
3718 might_sleep_if(extra_checks);
3721 return gpiod_get_array_value_complex(false, true, array_size,
3722 desc_array, array_info,
3725 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3728 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3729 * @desc: gpio whose value will be assigned
3730 * @value: value to assign
3732 * Set the raw value of the GPIO, i.e. the value of its physical line without
3733 * regard for its ACTIVE_LOW status.
3735 * This function is to be called from contexts that can sleep.
3737 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3739 might_sleep_if(extra_checks);
3740 VALIDATE_DESC_VOID(desc);
3741 gpiod_set_raw_value_commit(desc, value);
3743 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3746 * gpiod_set_value_cansleep() - assign a gpio's value
3747 * @desc: gpio whose value will be assigned
3748 * @value: value to assign
3750 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3753 * This function is to be called from contexts that can sleep.
3755 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3757 might_sleep_if(extra_checks);
3758 VALIDATE_DESC_VOID(desc);
3759 gpiod_set_value_nocheck(desc, value);
3761 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3764 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3765 * @array_size: number of elements in the descriptor array / value bitmap
3766 * @desc_array: array of GPIO descriptors whose values will be assigned
3767 * @array_info: information on applicability of fast bitmap processing path
3768 * @value_bitmap: bitmap of values to assign
3770 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3771 * without regard for their ACTIVE_LOW status.
3773 * This function is to be called from contexts that can sleep.
3775 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3776 struct gpio_desc **desc_array,
3777 struct gpio_array *array_info,
3778 unsigned long *value_bitmap)
3780 might_sleep_if(extra_checks);
3783 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3784 array_info, value_bitmap);
3786 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3789 * gpiod_add_lookup_tables() - register GPIO device consumers
3790 * @tables: list of tables of consumers to register
3791 * @n: number of tables in the list
3793 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3797 mutex_lock(&gpio_lookup_lock);
3799 for (i = 0; i < n; i++)
3800 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3802 mutex_unlock(&gpio_lookup_lock);
3806 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3807 * @array_size: number of elements in the descriptor array / value bitmap
3808 * @desc_array: array of GPIO descriptors whose values will be assigned
3809 * @array_info: information on applicability of fast bitmap processing path
3810 * @value_bitmap: bitmap of values to assign
3812 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3815 * This function is to be called from contexts that can sleep.
3817 int gpiod_set_array_value_cansleep(unsigned int array_size,
3818 struct gpio_desc **desc_array,
3819 struct gpio_array *array_info,
3820 unsigned long *value_bitmap)
3822 might_sleep_if(extra_checks);
3825 return gpiod_set_array_value_complex(false, true, array_size,
3826 desc_array, array_info,
3829 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3832 * gpiod_add_lookup_table() - register GPIO device consumers
3833 * @table: table of consumers to register
3835 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3837 mutex_lock(&gpio_lookup_lock);
3839 list_add_tail(&table->list, &gpio_lookup_list);
3841 mutex_unlock(&gpio_lookup_lock);
3843 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3846 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3847 * @table: table of consumers to unregister
3849 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3851 mutex_lock(&gpio_lookup_lock);
3853 list_del(&table->list);
3855 mutex_unlock(&gpio_lookup_lock);
3857 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3860 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
3861 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
3863 void gpiod_add_hogs(struct gpiod_hog *hogs)
3865 struct gpio_chip *chip;
3866 struct gpiod_hog *hog;
3868 mutex_lock(&gpio_machine_hogs_mutex);
3870 for (hog = &hogs[0]; hog->chip_label; hog++) {
3871 list_add_tail(&hog->list, &gpio_machine_hogs);
3874 * The chip may have been registered earlier, so check if it
3875 * exists and, if so, try to hog the line now.
3877 chip = find_chip_by_name(hog->chip_label);
3879 gpiochip_machine_hog(chip, hog);
3882 mutex_unlock(&gpio_machine_hogs_mutex);
3884 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
3886 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3888 const char *dev_id = dev ? dev_name(dev) : NULL;
3889 struct gpiod_lookup_table *table;
3891 mutex_lock(&gpio_lookup_lock);
3893 list_for_each_entry(table, &gpio_lookup_list, list) {
3894 if (table->dev_id && dev_id) {
3896 * Valid strings on both ends, must be identical to have
3899 if (!strcmp(table->dev_id, dev_id))
3903 * One of the pointers is NULL, so both must be to have
3906 if (dev_id == table->dev_id)
3913 mutex_unlock(&gpio_lookup_lock);
3917 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3919 enum gpio_lookup_flags *flags)
3921 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3922 struct gpiod_lookup_table *table;
3923 struct gpiod_lookup *p;
3925 table = gpiod_find_lookup_table(dev);
3929 for (p = &table->table[0]; p->chip_label; p++) {
3930 struct gpio_chip *chip;
3932 /* idx must always match exactly */
3936 /* If the lookup entry has a con_id, require exact match */
3937 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3940 chip = find_chip_by_name(p->chip_label);
3944 * As the lookup table indicates a chip with
3945 * p->chip_label should exist, assume it may
3946 * still appear later and let the interested
3947 * consumer be probed again or let the Deferred
3948 * Probe infrastructure handle the error.
3950 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
3952 return ERR_PTR(-EPROBE_DEFER);
3955 if (chip->ngpio <= p->chip_hwnum) {
3957 "requested GPIO %d is out of range [0..%d] for chip %s\n",
3958 idx, chip->ngpio, chip->label);
3959 return ERR_PTR(-EINVAL);
3962 desc = gpiochip_get_desc(chip, p->chip_hwnum);
3971 static int dt_gpio_count(struct device *dev, const char *con_id)
3977 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3979 snprintf(propname, sizeof(propname), "%s-%s",
3980 con_id, gpio_suffixes[i]);
3982 snprintf(propname, sizeof(propname), "%s",
3985 ret = of_gpio_named_count(dev->of_node, propname);
3989 return ret ? ret : -ENOENT;
3992 static int platform_gpio_count(struct device *dev, const char *con_id)
3994 struct gpiod_lookup_table *table;
3995 struct gpiod_lookup *p;
3996 unsigned int count = 0;
3998 table = gpiod_find_lookup_table(dev);
4002 for (p = &table->table[0]; p->chip_label; p++) {
4003 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
4004 (!con_id && !p->con_id))
4014 * gpiod_count - return the number of GPIOs associated with a device / function
4015 * or -ENOENT if no GPIO has been assigned to the requested function
4016 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4017 * @con_id: function within the GPIO consumer
4019 int gpiod_count(struct device *dev, const char *con_id)
4021 int count = -ENOENT;
4023 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
4024 count = dt_gpio_count(dev, con_id);
4025 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
4026 count = acpi_gpio_count(dev, con_id);
4029 count = platform_gpio_count(dev, con_id);
4033 EXPORT_SYMBOL_GPL(gpiod_count);
4036 * gpiod_get - obtain a GPIO for a given GPIO function
4037 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4038 * @con_id: function within the GPIO consumer
4039 * @flags: optional GPIO initialization flags
4041 * Return the GPIO descriptor corresponding to the function con_id of device
4042 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
4043 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
4045 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
4046 enum gpiod_flags flags)
4048 return gpiod_get_index(dev, con_id, 0, flags);
4050 EXPORT_SYMBOL_GPL(gpiod_get);
4053 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
4054 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4055 * @con_id: function within the GPIO consumer
4056 * @flags: optional GPIO initialization flags
4058 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
4059 * the requested function it will return NULL. This is convenient for drivers
4060 * that need to handle optional GPIOs.
4062 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
4064 enum gpiod_flags flags)
4066 return gpiod_get_index_optional(dev, con_id, 0, flags);
4068 EXPORT_SYMBOL_GPL(gpiod_get_optional);
4072 * gpiod_configure_flags - helper function to configure a given GPIO
4073 * @desc: gpio whose value will be assigned
4074 * @con_id: function within the GPIO consumer
4075 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
4077 * @dflags: gpiod_flags - optional GPIO initialization flags
4079 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
4080 * requested function and/or index, or another IS_ERR() code if an error
4081 * occurred while trying to acquire the GPIO.
4083 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
4084 unsigned long lflags, enum gpiod_flags dflags)
4088 if (lflags & GPIO_ACTIVE_LOW)
4089 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
4091 if (lflags & GPIO_OPEN_DRAIN)
4092 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4093 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
4095 * This enforces open drain mode from the consumer side.
4096 * This is necessary for some busses like I2C, but the lookup
4097 * should *REALLY* have specified them as open drain in the
4098 * first place, so print a little warning here.
4100 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4102 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
4105 if (lflags & GPIO_OPEN_SOURCE)
4106 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
4108 if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
4110 "both pull-up and pull-down enabled, invalid configuration\n");
4114 if (lflags & GPIO_PULL_UP)
4115 set_bit(FLAG_PULL_UP, &desc->flags);
4116 else if (lflags & GPIO_PULL_DOWN)
4117 set_bit(FLAG_PULL_DOWN, &desc->flags);
4119 status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
4123 /* No particular flag request, return here... */
4124 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
4125 pr_debug("no flags found for %s\n", con_id);
4130 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
4131 status = gpiod_direction_output(desc,
4132 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
4134 status = gpiod_direction_input(desc);
4140 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
4141 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4142 * @con_id: function within the GPIO consumer
4143 * @idx: index of the GPIO to obtain in the consumer
4144 * @flags: optional GPIO initialization flags
4146 * This variant of gpiod_get() allows to access GPIOs other than the first
4147 * defined one for functions that define several GPIOs.
4149 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
4150 * requested function and/or index, or another IS_ERR() code if an error
4151 * occurred while trying to acquire the GPIO.
4153 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
4156 enum gpiod_flags flags)
4158 struct gpio_desc *desc = NULL;
4160 enum gpio_lookup_flags lookupflags = 0;
4161 /* Maybe we have a device name, maybe not */
4162 const char *devname = dev ? dev_name(dev) : "?";
4164 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
4167 /* Using device tree? */
4168 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
4169 dev_dbg(dev, "using device tree for GPIO lookup\n");
4170 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
4171 } else if (ACPI_COMPANION(dev)) {
4172 dev_dbg(dev, "using ACPI for GPIO lookup\n");
4173 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
4178 * Either we are not using DT or ACPI, or their lookup did not return
4179 * a result. In that case, use platform lookup as a fallback.
4181 if (!desc || desc == ERR_PTR(-ENOENT)) {
4182 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
4183 desc = gpiod_find(dev, con_id, idx, &lookupflags);
4187 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
4192 * If a connection label was passed use that, else attempt to use
4193 * the device name as label
4195 status = gpiod_request(desc, con_id ? con_id : devname);
4197 if (status == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
4199 * This happens when there are several consumers for
4200 * the same GPIO line: we just return here without
4201 * further initialization. It is a bit if a hack.
4202 * This is necessary to support fixed regulators.
4204 * FIXME: Make this more sane and safe.
4206 dev_info(dev, "nonexclusive access to GPIO for %s\n",
4207 con_id ? con_id : devname);
4210 return ERR_PTR(status);
4214 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
4216 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
4218 return ERR_PTR(status);
4223 EXPORT_SYMBOL_GPL(gpiod_get_index);
4226 * gpiod_get_from_of_node() - obtain a GPIO from an OF node
4227 * @node: handle of the OF node
4228 * @propname: name of the DT property representing the GPIO
4229 * @index: index of the GPIO to obtain for the consumer
4230 * @dflags: GPIO initialization flags
4231 * @label: label to attach to the requested GPIO
4234 * On successful request the GPIO pin is configured in accordance with
4235 * provided @dflags. If the node does not have the requested GPIO
4236 * property, NULL is returned.
4238 * In case of error an ERR_PTR() is returned.
4240 struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
4241 const char *propname, int index,
4242 enum gpiod_flags dflags,
4245 struct gpio_desc *desc;
4246 unsigned long lflags = 0;
4247 enum of_gpio_flags flags;
4248 bool active_low = false;
4249 bool single_ended = false;
4250 bool open_drain = false;
4251 bool transitory = false;
4254 desc = of_get_named_gpiod_flags(node, propname,
4257 if (!desc || IS_ERR(desc)) {
4258 /* If it is not there, just return NULL */
4259 if (PTR_ERR(desc) == -ENOENT)
4264 active_low = flags & OF_GPIO_ACTIVE_LOW;
4265 single_ended = flags & OF_GPIO_SINGLE_ENDED;
4266 open_drain = flags & OF_GPIO_OPEN_DRAIN;
4267 transitory = flags & OF_GPIO_TRANSITORY;
4269 ret = gpiod_request(desc, label);
4270 if (ret == -EBUSY && (flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
4273 return ERR_PTR(ret);
4276 lflags |= GPIO_ACTIVE_LOW;
4280 lflags |= GPIO_OPEN_DRAIN;
4282 lflags |= GPIO_OPEN_SOURCE;
4286 lflags |= GPIO_TRANSITORY;
4288 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4291 return ERR_PTR(ret);
4296 EXPORT_SYMBOL(gpiod_get_from_of_node);
4299 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
4300 * @fwnode: handle of the firmware node
4301 * @propname: name of the firmware property representing the GPIO
4302 * @index: index of the GPIO to obtain for the consumer
4303 * @dflags: GPIO initialization flags
4304 * @label: label to attach to the requested GPIO
4306 * This function can be used for drivers that get their configuration
4307 * from opaque firmware.
4309 * The function properly finds the corresponding GPIO using whatever is the
4310 * underlying firmware interface and then makes sure that the GPIO
4311 * descriptor is requested before it is returned to the caller.
4314 * On successful request the GPIO pin is configured in accordance with
4317 * In case of error an ERR_PTR() is returned.
4319 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
4320 const char *propname, int index,
4321 enum gpiod_flags dflags,
4324 struct gpio_desc *desc = ERR_PTR(-ENODEV);
4325 unsigned long lflags = 0;
4329 return ERR_PTR(-EINVAL);
4331 if (is_of_node(fwnode)) {
4332 desc = gpiod_get_from_of_node(to_of_node(fwnode),
4337 } else if (is_acpi_node(fwnode)) {
4338 struct acpi_gpio_info info;
4340 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4344 acpi_gpio_update_gpiod_flags(&dflags, &info);
4346 if (info.polarity == GPIO_ACTIVE_LOW)
4347 lflags |= GPIO_ACTIVE_LOW;
4350 /* Currently only ACPI takes this path */
4351 ret = gpiod_request(desc, label);
4353 return ERR_PTR(ret);
4355 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4358 return ERR_PTR(ret);
4363 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4366 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4368 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4369 * @con_id: function within the GPIO consumer
4370 * @index: index of the GPIO to obtain in the consumer
4371 * @flags: optional GPIO initialization flags
4373 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4374 * specified index was assigned to the requested function it will return NULL.
4375 * This is convenient for drivers that need to handle optional GPIOs.
4377 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4380 enum gpiod_flags flags)
4382 struct gpio_desc *desc;
4384 desc = gpiod_get_index(dev, con_id, index, flags);
4386 if (PTR_ERR(desc) == -ENOENT)
4392 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4395 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4396 * @desc: gpio whose value will be assigned
4397 * @name: gpio line name
4398 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
4400 * @dflags: gpiod_flags - optional GPIO initialization flags
4402 int gpiod_hog(struct gpio_desc *desc, const char *name,
4403 unsigned long lflags, enum gpiod_flags dflags)
4405 struct gpio_chip *chip;
4406 struct gpio_desc *local_desc;
4410 chip = gpiod_to_chip(desc);
4411 hwnum = gpio_chip_hwgpio(desc);
4414 * FIXME: not very elegant that we call gpiod_configure_flags()
4415 * twice here (once inside gpiochip_request_own_desc() and
4416 * again here), but the gpiochip_request_own_desc() is external
4417 * and cannot really pass the lflags so this is the lesser evil
4418 * at the moment. Pass zero as dflags on this first call so we
4419 * don't screw anything up.
4421 local_desc = gpiochip_request_own_desc(chip, hwnum, name, 0);
4422 if (IS_ERR(local_desc)) {
4423 status = PTR_ERR(local_desc);
4424 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4425 name, chip->label, hwnum, status);
4429 status = gpiod_configure_flags(desc, name, lflags, dflags);
4431 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
4432 name, chip->label, hwnum, status);
4433 gpiochip_free_own_desc(desc);
4437 /* Mark GPIO as hogged so it can be identified and removed later */
4438 set_bit(FLAG_IS_HOGGED, &desc->flags);
4440 pr_info("GPIO line %d (%s) hogged as %s%s\n",
4441 desc_to_gpio(desc), name,
4442 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4443 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
4444 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
4450 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4451 * @chip: gpio chip to act on
4453 * This is only used by of_gpiochip_remove to free hogged gpios
4455 static void gpiochip_free_hogs(struct gpio_chip *chip)
4459 for (id = 0; id < chip->ngpio; id++) {
4460 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
4461 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
4466 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4467 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4468 * @con_id: function within the GPIO consumer
4469 * @flags: optional GPIO initialization flags
4471 * This function acquires all the GPIOs defined under a given function.
4473 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4474 * no GPIO has been assigned to the requested function, or another IS_ERR()
4475 * code if an error occurred while trying to acquire the GPIOs.
4477 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4479 enum gpiod_flags flags)
4481 struct gpio_desc *desc;
4482 struct gpio_descs *descs;
4483 struct gpio_array *array_info = NULL;
4484 struct gpio_chip *chip;
4485 int count, bitmap_size;
4487 count = gpiod_count(dev, con_id);
4489 return ERR_PTR(count);
4491 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4493 return ERR_PTR(-ENOMEM);
4495 for (descs->ndescs = 0; descs->ndescs < count; ) {
4496 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4498 gpiod_put_array(descs);
4499 return ERR_CAST(desc);
4502 descs->desc[descs->ndescs] = desc;
4504 chip = gpiod_to_chip(desc);
4506 * If pin hardware number of array member 0 is also 0, select
4507 * its chip as a candidate for fast bitmap processing path.
4509 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4510 struct gpio_descs *array;
4512 bitmap_size = BITS_TO_LONGS(chip->ngpio > count ?
4513 chip->ngpio : count);
4515 array = kzalloc(struct_size(descs, desc, count) +
4516 struct_size(array_info, invert_mask,
4517 3 * bitmap_size), GFP_KERNEL);
4519 gpiod_put_array(descs);
4520 return ERR_PTR(-ENOMEM);
4523 memcpy(array, descs,
4524 struct_size(descs, desc, descs->ndescs + 1));
4528 array_info = (void *)(descs->desc + count);
4529 array_info->get_mask = array_info->invert_mask +
4531 array_info->set_mask = array_info->get_mask +
4534 array_info->desc = descs->desc;
4535 array_info->size = count;
4536 array_info->chip = chip;
4537 bitmap_set(array_info->get_mask, descs->ndescs,
4538 count - descs->ndescs);
4539 bitmap_set(array_info->set_mask, descs->ndescs,
4540 count - descs->ndescs);
4541 descs->info = array_info;
4543 /* Unmark array members which don't belong to the 'fast' chip */
4544 if (array_info && array_info->chip != chip) {
4545 __clear_bit(descs->ndescs, array_info->get_mask);
4546 __clear_bit(descs->ndescs, array_info->set_mask);
4549 * Detect array members which belong to the 'fast' chip
4550 * but their pins are not in hardware order.
4552 else if (array_info &&
4553 gpio_chip_hwgpio(desc) != descs->ndescs) {
4555 * Don't use fast path if all array members processed so
4556 * far belong to the same chip as this one but its pin
4557 * hardware number is different from its array index.
4559 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4562 __clear_bit(descs->ndescs,
4563 array_info->get_mask);
4564 __clear_bit(descs->ndescs,
4565 array_info->set_mask);
4567 } else if (array_info) {
4568 /* Exclude open drain or open source from fast output */
4569 if (gpiochip_line_is_open_drain(chip, descs->ndescs) ||
4570 gpiochip_line_is_open_source(chip, descs->ndescs))
4571 __clear_bit(descs->ndescs,
4572 array_info->set_mask);
4573 /* Identify 'fast' pins which require invertion */
4574 if (gpiod_is_active_low(desc))
4575 __set_bit(descs->ndescs,
4576 array_info->invert_mask);
4583 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4584 array_info->chip->label, array_info->size,
4585 *array_info->get_mask, *array_info->set_mask,
4586 *array_info->invert_mask);
4589 EXPORT_SYMBOL_GPL(gpiod_get_array);
4592 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4594 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4595 * @con_id: function within the GPIO consumer
4596 * @flags: optional GPIO initialization flags
4598 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4599 * assigned to the requested function it will return NULL.
4601 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4603 enum gpiod_flags flags)
4605 struct gpio_descs *descs;
4607 descs = gpiod_get_array(dev, con_id, flags);
4608 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
4613 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4616 * gpiod_put - dispose of a GPIO descriptor
4617 * @desc: GPIO descriptor to dispose of
4619 * No descriptor can be used after gpiod_put() has been called on it.
4621 void gpiod_put(struct gpio_desc *desc)
4625 EXPORT_SYMBOL_GPL(gpiod_put);
4628 * gpiod_put_array - dispose of multiple GPIO descriptors
4629 * @descs: struct gpio_descs containing an array of descriptors
4631 void gpiod_put_array(struct gpio_descs *descs)
4635 for (i = 0; i < descs->ndescs; i++)
4636 gpiod_put(descs->desc[i]);
4640 EXPORT_SYMBOL_GPL(gpiod_put_array);
4642 static int __init gpiolib_dev_init(void)
4646 /* Register GPIO sysfs bus */
4647 ret = bus_register(&gpio_bus_type);
4649 pr_err("gpiolib: could not register GPIO bus type\n");
4653 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
4655 pr_err("gpiolib: failed to allocate char dev region\n");
4656 bus_unregister(&gpio_bus_type);
4658 gpiolib_initialized = true;
4659 gpiochip_setup_devs();
4663 core_initcall(gpiolib_dev_init);
4665 #ifdef CONFIG_DEBUG_FS
4667 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4670 struct gpio_chip *chip = gdev->chip;
4671 unsigned gpio = gdev->base;
4672 struct gpio_desc *gdesc = &gdev->descs[0];
4677 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4678 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4680 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4686 gpiod_get_direction(gdesc);
4687 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4688 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4689 active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
4690 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
4691 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4692 is_out ? "out" : "in ",
4693 chip->get ? (chip->get(chip, i) ? "hi" : "lo") : "? ",
4694 is_irq ? "IRQ " : "",
4695 active_low ? "ACTIVE LOW" : "");
4696 seq_printf(s, "\n");
4700 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4702 unsigned long flags;
4703 struct gpio_device *gdev = NULL;
4704 loff_t index = *pos;
4708 spin_lock_irqsave(&gpio_lock, flags);
4709 list_for_each_entry(gdev, &gpio_devices, list)
4711 spin_unlock_irqrestore(&gpio_lock, flags);
4714 spin_unlock_irqrestore(&gpio_lock, flags);
4719 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4721 unsigned long flags;
4722 struct gpio_device *gdev = v;
4725 spin_lock_irqsave(&gpio_lock, flags);
4726 if (list_is_last(&gdev->list, &gpio_devices))
4729 ret = list_entry(gdev->list.next, struct gpio_device, list);
4730 spin_unlock_irqrestore(&gpio_lock, flags);
4738 static void gpiolib_seq_stop(struct seq_file *s, void *v)
4742 static int gpiolib_seq_show(struct seq_file *s, void *v)
4744 struct gpio_device *gdev = v;
4745 struct gpio_chip *chip = gdev->chip;
4746 struct device *parent;
4749 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4750 dev_name(&gdev->dev));
4754 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4755 dev_name(&gdev->dev),
4756 gdev->base, gdev->base + gdev->ngpio - 1);
4757 parent = chip->parent;
4759 seq_printf(s, ", parent: %s/%s",
4760 parent->bus ? parent->bus->name : "no-bus",
4763 seq_printf(s, ", %s", chip->label);
4764 if (chip->can_sleep)
4765 seq_printf(s, ", can sleep");
4766 seq_printf(s, ":\n");
4769 chip->dbg_show(s, chip);
4771 gpiolib_dbg_show(s, gdev);
4776 static const struct seq_operations gpiolib_seq_ops = {
4777 .start = gpiolib_seq_start,
4778 .next = gpiolib_seq_next,
4779 .stop = gpiolib_seq_stop,
4780 .show = gpiolib_seq_show,
4783 static int gpiolib_open(struct inode *inode, struct file *file)
4785 return seq_open(file, &gpiolib_seq_ops);
4788 static const struct file_operations gpiolib_operations = {
4789 .owner = THIS_MODULE,
4790 .open = gpiolib_open,
4792 .llseek = seq_lseek,
4793 .release = seq_release,
4796 static int __init gpiolib_debugfs_init(void)
4798 /* /sys/kernel/debug/gpio */
4799 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
4800 NULL, NULL, &gpiolib_operations);
4803 subsys_initcall(gpiolib_debugfs_init);
4805 #endif /* DEBUG_FS */