1 #include <linux/kernel.h>
2 #include <linux/module.h>
3 #include <linux/interrupt.h>
5 #include <linux/spinlock.h>
6 #include <linux/list.h>
7 #include <linux/device.h>
9 #include <linux/debugfs.h>
10 #include <linux/seq_file.h>
11 #include <linux/gpio.h>
12 #include <linux/of_gpio.h>
13 #include <linux/idr.h>
14 #include <linux/slab.h>
15 #include <linux/acpi.h>
16 #include <linux/gpio/driver.h>
17 #include <linux/gpio/machine.h>
18 #include <linux/pinctrl/consumer.h>
19 #include <linux/cdev.h>
21 #include <linux/uaccess.h>
22 #include <linux/compat.h>
23 #include <linux/anon_inodes.h>
24 #include <linux/file.h>
25 #include <linux/kfifo.h>
26 #include <linux/poll.h>
27 #include <linux/timekeeping.h>
28 #include <uapi/linux/gpio.h>
32 #define CREATE_TRACE_POINTS
33 #include <trace/events/gpio.h>
35 /* Implementation infrastructure for GPIO interfaces.
37 * The GPIO programming interface allows for inlining speed-critical
38 * get/set operations for common cases, so that access to SOC-integrated
39 * GPIOs can sometimes cost only an instruction or two per bit.
43 /* When debugging, extend minimal trust to callers and platform code.
44 * Also emit diagnostic messages that may help initial bringup, when
45 * board setup or driver bugs are most common.
47 * Otherwise, minimize overhead in what may be bitbanging codepaths.
50 #define extra_checks 1
52 #define extra_checks 0
55 /* Device and char device-related information */
56 static DEFINE_IDA(gpio_ida);
57 static dev_t gpio_devt;
58 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
59 static struct bus_type gpio_bus_type = {
63 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
64 * While any GPIO is requested, its gpio_chip is not removable;
65 * each GPIO's "requested" flag serves as a lock and refcount.
67 DEFINE_SPINLOCK(gpio_lock);
69 static DEFINE_MUTEX(gpio_lookup_lock);
70 static LIST_HEAD(gpio_lookup_list);
71 LIST_HEAD(gpio_devices);
73 static void gpiochip_free_hogs(struct gpio_chip *chip);
74 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
75 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
76 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
78 static bool gpiolib_initialized;
80 static inline void desc_set_label(struct gpio_desc *d, const char *label)
86 * Convert a GPIO number to its descriptor
88 struct gpio_desc *gpio_to_desc(unsigned gpio)
90 struct gpio_device *gdev;
93 spin_lock_irqsave(&gpio_lock, flags);
95 list_for_each_entry(gdev, &gpio_devices, list) {
96 if (gdev->base <= gpio &&
97 gdev->base + gdev->ngpio > gpio) {
98 spin_unlock_irqrestore(&gpio_lock, flags);
99 return &gdev->descs[gpio - gdev->base];
103 spin_unlock_irqrestore(&gpio_lock, flags);
105 if (!gpio_is_valid(gpio))
106 WARN(1, "invalid GPIO %d\n", gpio);
110 EXPORT_SYMBOL_GPL(gpio_to_desc);
113 * Get the GPIO descriptor corresponding to the given hw number for this chip.
115 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
118 struct gpio_device *gdev = chip->gpiodev;
120 if (hwnum >= gdev->ngpio)
121 return ERR_PTR(-EINVAL);
123 return &gdev->descs[hwnum];
127 * Convert a GPIO descriptor to the integer namespace.
128 * This should disappear in the future but is needed since we still
129 * use GPIO numbers for error messages and sysfs nodes
131 int desc_to_gpio(const struct gpio_desc *desc)
133 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
135 EXPORT_SYMBOL_GPL(desc_to_gpio);
139 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
140 * @desc: descriptor to return the chip of
142 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
144 if (!desc || !desc->gdev || !desc->gdev->chip)
146 return desc->gdev->chip;
148 EXPORT_SYMBOL_GPL(gpiod_to_chip);
150 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
151 static int gpiochip_find_base(int ngpio)
153 struct gpio_device *gdev;
154 int base = ARCH_NR_GPIOS - ngpio;
156 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
157 /* found a free space? */
158 if (gdev->base + gdev->ngpio <= base)
161 /* nope, check the space right before the chip */
162 base = gdev->base - ngpio;
165 if (gpio_is_valid(base)) {
166 pr_debug("%s: found new base at %d\n", __func__, base);
169 pr_err("%s: cannot find free range\n", __func__);
175 * gpiod_get_direction - return the current direction of a GPIO
176 * @desc: GPIO to get the direction of
178 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
180 * This function may sleep if gpiod_cansleep() is true.
182 int gpiod_get_direction(struct gpio_desc *desc)
184 struct gpio_chip *chip;
186 int status = -EINVAL;
188 chip = gpiod_to_chip(desc);
189 offset = gpio_chip_hwgpio(desc);
191 if (!chip->get_direction)
194 status = chip->get_direction(chip, offset);
196 /* GPIOF_DIR_IN, or other positive */
198 clear_bit(FLAG_IS_OUT, &desc->flags);
202 set_bit(FLAG_IS_OUT, &desc->flags);
206 EXPORT_SYMBOL_GPL(gpiod_get_direction);
209 * Add a new chip to the global chips list, keeping the list of chips sorted
210 * by range(means [base, base + ngpio - 1]) order.
212 * Return -EBUSY if the new chip overlaps with some other chip's integer
215 static int gpiodev_add_to_list(struct gpio_device *gdev)
217 struct gpio_device *prev, *next;
219 if (list_empty(&gpio_devices)) {
220 /* initial entry in list */
221 list_add_tail(&gdev->list, &gpio_devices);
225 next = list_entry(gpio_devices.next, struct gpio_device, list);
226 if (gdev->base + gdev->ngpio <= next->base) {
227 /* add before first entry */
228 list_add(&gdev->list, &gpio_devices);
232 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
233 if (prev->base + prev->ngpio <= gdev->base) {
234 /* add behind last entry */
235 list_add_tail(&gdev->list, &gpio_devices);
239 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
240 /* at the end of the list */
241 if (&next->list == &gpio_devices)
244 /* add between prev and next */
245 if (prev->base + prev->ngpio <= gdev->base
246 && gdev->base + gdev->ngpio <= next->base) {
247 list_add(&gdev->list, &prev->list);
252 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
257 * Convert a GPIO name to its descriptor
259 static struct gpio_desc *gpio_name_to_desc(const char * const name)
261 struct gpio_device *gdev;
264 spin_lock_irqsave(&gpio_lock, flags);
266 list_for_each_entry(gdev, &gpio_devices, list) {
269 for (i = 0; i != gdev->ngpio; ++i) {
270 struct gpio_desc *desc = &gdev->descs[i];
272 if (!desc->name || !name)
275 if (!strcmp(desc->name, name)) {
276 spin_unlock_irqrestore(&gpio_lock, flags);
282 spin_unlock_irqrestore(&gpio_lock, flags);
288 * Takes the names from gc->names and checks if they are all unique. If they
289 * are, they are assigned to their gpio descriptors.
291 * Warning if one of the names is already used for a different GPIO.
293 static int gpiochip_set_desc_names(struct gpio_chip *gc)
295 struct gpio_device *gdev = gc->gpiodev;
301 /* First check all names if they are unique */
302 for (i = 0; i != gc->ngpio; ++i) {
303 struct gpio_desc *gpio;
305 gpio = gpio_name_to_desc(gc->names[i]);
308 "Detected name collision for GPIO name '%s'\n",
312 /* Then add all names to the GPIO descriptors */
313 for (i = 0; i != gc->ngpio; ++i)
314 gdev->descs[i].name = gc->names[i];
320 * GPIO line handle management
324 * struct linehandle_state - contains the state of a userspace handle
325 * @gdev: the GPIO device the handle pertains to
326 * @label: consumer label used to tag descriptors
327 * @descs: the GPIO descriptors held by this handle
328 * @numdescs: the number of descriptors held in the descs array
330 struct linehandle_state {
331 struct gpio_device *gdev;
333 struct gpio_desc *descs[GPIOHANDLES_MAX];
337 #define GPIOHANDLE_REQUEST_VALID_FLAGS \
338 (GPIOHANDLE_REQUEST_INPUT | \
339 GPIOHANDLE_REQUEST_OUTPUT | \
340 GPIOHANDLE_REQUEST_ACTIVE_LOW | \
341 GPIOHANDLE_REQUEST_OPEN_DRAIN | \
342 GPIOHANDLE_REQUEST_OPEN_SOURCE)
344 static long linehandle_ioctl(struct file *filep, unsigned int cmd,
347 struct linehandle_state *lh = filep->private_data;
348 void __user *ip = (void __user *)arg;
349 struct gpiohandle_data ghd;
352 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
355 memset(&ghd, 0, sizeof(ghd));
357 /* TODO: check if descriptors are really input */
358 for (i = 0; i < lh->numdescs; i++) {
359 val = gpiod_get_value_cansleep(lh->descs[i]);
365 if (copy_to_user(ip, &ghd, sizeof(ghd)))
369 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
370 int vals[GPIOHANDLES_MAX];
372 /* TODO: check if descriptors are really output */
373 if (copy_from_user(&ghd, ip, sizeof(ghd)))
376 /* Clamp all values to [0,1] */
377 for (i = 0; i < lh->numdescs; i++)
378 vals[i] = !!ghd.values[i];
380 /* Reuse the array setting function */
381 gpiod_set_array_value_complex(false,
392 static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
395 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
399 static int linehandle_release(struct inode *inode, struct file *filep)
401 struct linehandle_state *lh = filep->private_data;
402 struct gpio_device *gdev = lh->gdev;
405 for (i = 0; i < lh->numdescs; i++)
406 gpiod_free(lh->descs[i]);
409 put_device(&gdev->dev);
413 static const struct file_operations linehandle_fileops = {
414 .release = linehandle_release,
415 .owner = THIS_MODULE,
416 .llseek = noop_llseek,
417 .unlocked_ioctl = linehandle_ioctl,
419 .compat_ioctl = linehandle_ioctl_compat,
423 static int linehandle_create(struct gpio_device *gdev, void __user *ip)
425 struct gpiohandle_request handlereq;
426 struct linehandle_state *lh;
430 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
432 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
435 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
439 get_device(&gdev->dev);
441 /* Make sure this is terminated */
442 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
443 if (strlen(handlereq.consumer_label)) {
444 lh->label = kstrdup(handlereq.consumer_label,
452 /* Request each GPIO */
453 for (i = 0; i < handlereq.lines; i++) {
454 u32 offset = handlereq.lineoffsets[i];
455 u32 lflags = handlereq.flags;
456 struct gpio_desc *desc;
458 if (offset >= gdev->ngpio) {
463 /* Return an error if a unknown flag is set */
464 if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) {
469 desc = &gdev->descs[offset];
470 ret = gpiod_request(desc, lh->label);
475 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
476 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
477 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
478 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
479 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
480 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
483 * Lines have to be requested explicitly for input
484 * or output, else the line will be treated "as is".
486 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
487 int val = !!handlereq.default_values[i];
489 ret = gpiod_direction_output(desc, val);
492 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
493 ret = gpiod_direction_input(desc);
497 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
500 /* Let i point at the last handle */
502 lh->numdescs = handlereq.lines;
504 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
510 file = anon_inode_getfile("gpio-linehandle",
513 O_RDONLY | O_CLOEXEC);
516 goto out_put_unused_fd;
520 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
522 * fput() will trigger the release() callback, so do not go onto
523 * the regular error cleanup path here.
530 fd_install(fd, file);
532 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
541 gpiod_free(lh->descs[i]);
545 put_device(&gdev->dev);
550 * GPIO line event management
554 * struct lineevent_state - contains the state of a userspace event
555 * @gdev: the GPIO device the event pertains to
556 * @label: consumer label used to tag descriptors
557 * @desc: the GPIO descriptor held by this event
558 * @eflags: the event flags this line was requested with
559 * @irq: the interrupt that trigger in response to events on this GPIO
560 * @wait: wait queue that handles blocking reads of events
561 * @events: KFIFO for the GPIO events
562 * @read_lock: mutex lock to protect reads from colliding with adding
563 * new events to the FIFO
565 struct lineevent_state {
566 struct gpio_device *gdev;
568 struct gpio_desc *desc;
571 wait_queue_head_t wait;
572 DECLARE_KFIFO(events, struct gpioevent_data, 16);
573 struct mutex read_lock;
576 #define GPIOEVENT_REQUEST_VALID_FLAGS \
577 (GPIOEVENT_REQUEST_RISING_EDGE | \
578 GPIOEVENT_REQUEST_FALLING_EDGE)
580 static unsigned int lineevent_poll(struct file *filep,
581 struct poll_table_struct *wait)
583 struct lineevent_state *le = filep->private_data;
584 unsigned int events = 0;
586 poll_wait(filep, &le->wait, wait);
588 if (!kfifo_is_empty(&le->events))
589 events = POLLIN | POLLRDNORM;
595 static ssize_t lineevent_read(struct file *filep,
600 struct lineevent_state *le = filep->private_data;
604 if (count < sizeof(struct gpioevent_data))
608 if (kfifo_is_empty(&le->events)) {
609 if (filep->f_flags & O_NONBLOCK)
612 ret = wait_event_interruptible(le->wait,
613 !kfifo_is_empty(&le->events));
618 if (mutex_lock_interruptible(&le->read_lock))
620 ret = kfifo_to_user(&le->events, buf, count, &copied);
621 mutex_unlock(&le->read_lock);
627 * If we couldn't read anything from the fifo (a different
628 * thread might have been faster) we either return -EAGAIN if
629 * the file descriptor is non-blocking, otherwise we go back to
630 * sleep and wait for more data to arrive.
632 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
635 } while (copied == 0);
640 static int lineevent_release(struct inode *inode, struct file *filep)
642 struct lineevent_state *le = filep->private_data;
643 struct gpio_device *gdev = le->gdev;
645 free_irq(le->irq, le);
646 gpiod_free(le->desc);
649 put_device(&gdev->dev);
653 static long lineevent_ioctl(struct file *filep, unsigned int cmd,
656 struct lineevent_state *le = filep->private_data;
657 void __user *ip = (void __user *)arg;
658 struct gpiohandle_data ghd;
661 * We can get the value for an event line but not set it,
662 * because it is input by definition.
664 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
667 memset(&ghd, 0, sizeof(ghd));
669 val = gpiod_get_value_cansleep(le->desc);
674 if (copy_to_user(ip, &ghd, sizeof(ghd)))
683 static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
686 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
690 static const struct file_operations lineevent_fileops = {
691 .release = lineevent_release,
692 .read = lineevent_read,
693 .poll = lineevent_poll,
694 .owner = THIS_MODULE,
695 .llseek = noop_llseek,
696 .unlocked_ioctl = lineevent_ioctl,
698 .compat_ioctl = lineevent_ioctl_compat,
702 static irqreturn_t lineevent_irq_thread(int irq, void *p)
704 struct lineevent_state *le = p;
705 struct gpioevent_data ge;
708 ge.timestamp = ktime_get_real_ns();
710 if (le->eflags & GPIOEVENT_REQUEST_BOTH_EDGES) {
711 int level = gpiod_get_value_cansleep(le->desc);
714 /* Emit low-to-high event */
715 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
717 /* Emit high-to-low event */
718 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
719 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
720 /* Emit low-to-high event */
721 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
722 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
723 /* Emit high-to-low event */
724 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
729 ret = kfifo_put(&le->events, ge);
731 wake_up_poll(&le->wait, POLLIN);
736 static int lineevent_create(struct gpio_device *gdev, void __user *ip)
738 struct gpioevent_request eventreq;
739 struct lineevent_state *le;
740 struct gpio_desc *desc;
749 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
752 le = kzalloc(sizeof(*le), GFP_KERNEL);
756 get_device(&gdev->dev);
758 /* Make sure this is terminated */
759 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
760 if (strlen(eventreq.consumer_label)) {
761 le->label = kstrdup(eventreq.consumer_label,
769 offset = eventreq.lineoffset;
770 lflags = eventreq.handleflags;
771 eflags = eventreq.eventflags;
773 if (offset >= gdev->ngpio) {
778 /* Return an error if a unknown flag is set */
779 if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
780 (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
785 /* This is just wrong: we don't look for events on output lines */
786 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
791 desc = &gdev->descs[offset];
792 ret = gpiod_request(desc, le->label);
798 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
799 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
800 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
801 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
802 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
803 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
805 ret = gpiod_direction_input(desc);
809 le->irq = gpiod_to_irq(desc);
815 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
816 irqflags |= IRQF_TRIGGER_RISING;
817 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
818 irqflags |= IRQF_TRIGGER_FALLING;
819 irqflags |= IRQF_ONESHOT;
820 irqflags |= IRQF_SHARED;
822 INIT_KFIFO(le->events);
823 init_waitqueue_head(&le->wait);
824 mutex_init(&le->read_lock);
826 /* Request a thread to read the events */
827 ret = request_threaded_irq(le->irq,
829 lineevent_irq_thread,
836 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
842 file = anon_inode_getfile("gpio-event",
845 O_RDONLY | O_CLOEXEC);
848 goto out_put_unused_fd;
852 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
854 * fput() will trigger the release() callback, so do not go onto
855 * the regular error cleanup path here.
862 fd_install(fd, file);
869 free_irq(le->irq, le);
871 gpiod_free(le->desc);
876 put_device(&gdev->dev);
881 * gpio_ioctl() - ioctl handler for the GPIO chardev
883 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
885 struct gpio_device *gdev = filp->private_data;
886 struct gpio_chip *chip = gdev->chip;
887 void __user *ip = (void __user *)arg;
889 /* We fail any subsequent ioctl():s when the chip is gone */
893 /* Fill in the struct and pass to userspace */
894 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
895 struct gpiochip_info chipinfo;
897 memset(&chipinfo, 0, sizeof(chipinfo));
899 strncpy(chipinfo.name, dev_name(&gdev->dev),
900 sizeof(chipinfo.name));
901 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
902 strncpy(chipinfo.label, gdev->label,
903 sizeof(chipinfo.label));
904 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
905 chipinfo.lines = gdev->ngpio;
906 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
909 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
910 struct gpioline_info lineinfo;
911 struct gpio_desc *desc;
913 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
915 if (lineinfo.line_offset >= gdev->ngpio)
918 desc = &gdev->descs[lineinfo.line_offset];
920 strncpy(lineinfo.name, desc->name,
921 sizeof(lineinfo.name));
922 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
924 lineinfo.name[0] = '\0';
927 strncpy(lineinfo.consumer, desc->label,
928 sizeof(lineinfo.consumer));
929 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
931 lineinfo.consumer[0] = '\0';
935 * Userspace only need to know that the kernel is using
936 * this GPIO so it can't use it.
939 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
940 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
941 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
942 test_bit(FLAG_EXPORT, &desc->flags) ||
943 test_bit(FLAG_SYSFS, &desc->flags))
944 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
945 if (test_bit(FLAG_IS_OUT, &desc->flags))
946 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
947 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
948 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
949 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
950 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
951 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
952 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
954 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
957 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
958 return linehandle_create(gdev, ip);
959 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
960 return lineevent_create(gdev, ip);
966 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
969 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
974 * gpio_chrdev_open() - open the chardev for ioctl operations
975 * @inode: inode for this chardev
976 * @filp: file struct for storing private data
977 * Returns 0 on success
979 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
981 struct gpio_device *gdev = container_of(inode->i_cdev,
982 struct gpio_device, chrdev);
984 /* Fail on open if the backing gpiochip is gone */
985 if (!gdev || !gdev->chip)
987 get_device(&gdev->dev);
988 filp->private_data = gdev;
993 * gpio_chrdev_release() - close chardev after ioctl operations
994 * @inode: inode for this chardev
995 * @filp: file struct for storing private data
996 * Returns 0 on success
998 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1000 struct gpio_device *gdev = container_of(inode->i_cdev,
1001 struct gpio_device, chrdev);
1005 put_device(&gdev->dev);
1010 static const struct file_operations gpio_fileops = {
1011 .release = gpio_chrdev_release,
1012 .open = gpio_chrdev_open,
1013 .owner = THIS_MODULE,
1014 .llseek = noop_llseek,
1015 .unlocked_ioctl = gpio_ioctl,
1016 #ifdef CONFIG_COMPAT
1017 .compat_ioctl = gpio_ioctl_compat,
1021 static void gpiodevice_release(struct device *dev)
1023 struct gpio_device *gdev = dev_get_drvdata(dev);
1025 list_del(&gdev->list);
1026 ida_simple_remove(&gpio_ida, gdev->id);
1032 static int gpiochip_setup_dev(struct gpio_device *gdev)
1036 cdev_init(&gdev->chrdev, &gpio_fileops);
1037 gdev->chrdev.owner = THIS_MODULE;
1038 gdev->chrdev.kobj.parent = &gdev->dev.kobj;
1039 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1040 status = cdev_add(&gdev->chrdev, gdev->dev.devt, 1);
1042 chip_warn(gdev->chip, "failed to add char device %d:%d\n",
1043 MAJOR(gpio_devt), gdev->id);
1045 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1046 MAJOR(gpio_devt), gdev->id);
1047 status = device_add(&gdev->dev);
1049 goto err_remove_chardev;
1051 status = gpiochip_sysfs_register(gdev);
1053 goto err_remove_device;
1055 /* From this point, the .release() function cleans up gpio_device */
1056 gdev->dev.release = gpiodevice_release;
1057 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1058 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1059 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1064 device_del(&gdev->dev);
1066 cdev_del(&gdev->chrdev);
1070 static void gpiochip_setup_devs(void)
1072 struct gpio_device *gdev;
1075 list_for_each_entry(gdev, &gpio_devices, list) {
1076 err = gpiochip_setup_dev(gdev);
1078 pr_err("%s: Failed to initialize gpio device (%d)\n",
1079 dev_name(&gdev->dev), err);
1084 * gpiochip_add_data() - register a gpio_chip
1085 * @chip: the chip to register, with chip->base initialized
1086 * Context: potentially before irqs will work
1088 * Returns a negative errno if the chip can't be registered, such as
1089 * because the chip->base is invalid or already associated with a
1090 * different chip. Otherwise it returns zero as a success code.
1092 * When gpiochip_add_data() is called very early during boot, so that GPIOs
1093 * can be freely used, the chip->parent device must be registered before
1094 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
1095 * for GPIOs will fail rudely.
1097 * gpiochip_add_data() must only be called after gpiolib initialization,
1098 * ie after core_initcall().
1100 * If chip->base is negative, this requests dynamic assignment of
1101 * a range of valid GPIOs.
1103 int gpiochip_add_data(struct gpio_chip *chip, void *data)
1105 unsigned long flags;
1108 int base = chip->base;
1109 struct gpio_device *gdev;
1112 * First: allocate and populate the internal stat container, and
1113 * set up the struct device.
1115 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1118 gdev->dev.bus = &gpio_bus_type;
1120 chip->gpiodev = gdev;
1122 gdev->dev.parent = chip->parent;
1123 gdev->dev.of_node = chip->parent->of_node;
1126 #ifdef CONFIG_OF_GPIO
1127 /* If the gpiochip has an assigned OF node this takes precedence */
1129 gdev->dev.of_node = chip->of_node;
1132 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1137 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1138 device_initialize(&gdev->dev);
1139 dev_set_drvdata(&gdev->dev, gdev);
1140 if (chip->parent && chip->parent->driver)
1141 gdev->owner = chip->parent->driver->owner;
1142 else if (chip->owner)
1143 /* TODO: remove chip->owner */
1144 gdev->owner = chip->owner;
1146 gdev->owner = THIS_MODULE;
1148 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1154 if (chip->ngpio == 0) {
1155 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1157 goto err_free_descs;
1161 gdev->label = kstrdup(chip->label, GFP_KERNEL);
1163 gdev->label = kstrdup("unknown", GFP_KERNEL);
1166 goto err_free_descs;
1169 gdev->ngpio = chip->ngpio;
1172 spin_lock_irqsave(&gpio_lock, flags);
1175 * TODO: this allocates a Linux GPIO number base in the global
1176 * GPIO numberspace for this chip. In the long run we want to
1177 * get *rid* of this numberspace and use only descriptors, but
1178 * it may be a pipe dream. It will not happen before we get rid
1179 * of the sysfs interface anyways.
1182 base = gpiochip_find_base(chip->ngpio);
1185 spin_unlock_irqrestore(&gpio_lock, flags);
1186 goto err_free_label;
1189 * TODO: it should not be necessary to reflect the assigned
1190 * base outside of the GPIO subsystem. Go over drivers and
1191 * see if anyone makes use of this, else drop this and assign
1198 status = gpiodev_add_to_list(gdev);
1200 spin_unlock_irqrestore(&gpio_lock, flags);
1201 goto err_free_label;
1204 spin_unlock_irqrestore(&gpio_lock, flags);
1206 for (i = 0; i < chip->ngpio; i++) {
1207 struct gpio_desc *desc = &gdev->descs[i];
1211 * REVISIT: most hardware initializes GPIOs as inputs
1212 * (often with pullups enabled) so power usage is
1213 * minimized. Linux code should set the gpio direction
1214 * first thing; but until it does, and in case
1215 * chip->get_direction is not set, we may expose the
1216 * wrong direction in sysfs.
1219 if (chip->get_direction) {
1221 * If we have .get_direction, set up the initial
1222 * direction flag from the hardware.
1224 int dir = chip->get_direction(chip, i);
1227 set_bit(FLAG_IS_OUT, &desc->flags);
1228 } else if (!chip->direction_input) {
1230 * If the chip lacks the .direction_input callback
1231 * we logically assume all lines are outputs.
1233 set_bit(FLAG_IS_OUT, &desc->flags);
1237 #ifdef CONFIG_PINCTRL
1238 INIT_LIST_HEAD(&gdev->pin_ranges);
1241 status = gpiochip_set_desc_names(chip);
1243 goto err_remove_from_list;
1245 status = gpiochip_irqchip_init_valid_mask(chip);
1247 goto err_remove_from_list;
1249 status = of_gpiochip_add(chip);
1251 goto err_remove_chip;
1253 acpi_gpiochip_add(chip);
1256 * By first adding the chardev, and then adding the device,
1257 * we get a device node entry in sysfs under
1258 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1259 * coldplug of device nodes and other udev business.
1260 * We can do this only if gpiolib has been initialized.
1261 * Otherwise, defer until later.
1263 if (gpiolib_initialized) {
1264 status = gpiochip_setup_dev(gdev);
1266 goto err_remove_chip;
1271 acpi_gpiochip_remove(chip);
1272 gpiochip_free_hogs(chip);
1273 of_gpiochip_remove(chip);
1274 gpiochip_irqchip_free_valid_mask(chip);
1275 err_remove_from_list:
1276 spin_lock_irqsave(&gpio_lock, flags);
1277 list_del(&gdev->list);
1278 spin_unlock_irqrestore(&gpio_lock, flags);
1284 ida_simple_remove(&gpio_ida, gdev->id);
1285 /* failures here can mean systems won't boot... */
1286 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
1287 gdev->base, gdev->base + gdev->ngpio - 1,
1288 chip->label ? : "generic");
1292 EXPORT_SYMBOL_GPL(gpiochip_add_data);
1295 * gpiochip_get_data() - get per-subdriver data for the chip
1297 void *gpiochip_get_data(struct gpio_chip *chip)
1299 return chip->gpiodev->data;
1301 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1304 * gpiochip_remove() - unregister a gpio_chip
1305 * @chip: the chip to unregister
1307 * A gpio_chip with any GPIOs still requested may not be removed.
1309 void gpiochip_remove(struct gpio_chip *chip)
1311 struct gpio_device *gdev = chip->gpiodev;
1312 struct gpio_desc *desc;
1313 unsigned long flags;
1315 bool requested = false;
1317 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1318 gpiochip_sysfs_unregister(gdev);
1319 /* Numb the device, cancelling all outstanding operations */
1321 gpiochip_irqchip_remove(chip);
1322 acpi_gpiochip_remove(chip);
1323 gpiochip_remove_pin_ranges(chip);
1324 gpiochip_free_hogs(chip);
1325 of_gpiochip_remove(chip);
1327 * We accept no more calls into the driver from this point, so
1328 * NULL the driver data pointer
1332 spin_lock_irqsave(&gpio_lock, flags);
1333 for (i = 0; i < gdev->ngpio; i++) {
1334 desc = &gdev->descs[i];
1335 if (test_bit(FLAG_REQUESTED, &desc->flags))
1338 spin_unlock_irqrestore(&gpio_lock, flags);
1341 dev_crit(&gdev->dev,
1342 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1345 * The gpiochip side puts its use of the device to rest here:
1346 * if there are no userspace clients, the chardev and device will
1347 * be removed, else it will be dangling until the last user is
1350 cdev_del(&gdev->chrdev);
1351 device_del(&gdev->dev);
1352 put_device(&gdev->dev);
1354 EXPORT_SYMBOL_GPL(gpiochip_remove);
1356 static void devm_gpio_chip_release(struct device *dev, void *res)
1358 struct gpio_chip *chip = *(struct gpio_chip **)res;
1360 gpiochip_remove(chip);
1363 static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
1366 struct gpio_chip **r = res;
1377 * devm_gpiochip_add_data() - Resource manager piochip_add_data()
1378 * @dev: the device pointer on which irq_chip belongs to.
1379 * @chip: the chip to register, with chip->base initialized
1380 * Context: potentially before irqs will work
1382 * Returns a negative errno if the chip can't be registered, such as
1383 * because the chip->base is invalid or already associated with a
1384 * different chip. Otherwise it returns zero as a success code.
1386 * The gpio chip automatically be released when the device is unbound.
1388 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1391 struct gpio_chip **ptr;
1394 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1399 ret = gpiochip_add_data(chip, data);
1406 devres_add(dev, ptr);
1410 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1413 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1414 * @dev: device for which which resource was allocated
1415 * @chip: the chip to remove
1417 * A gpio_chip with any GPIOs still requested may not be removed.
1419 void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
1423 ret = devres_release(dev, devm_gpio_chip_release,
1424 devm_gpio_chip_match, chip);
1428 EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
1431 * gpiochip_find() - iterator for locating a specific gpio_chip
1432 * @data: data to pass to match function
1433 * @callback: Callback function to check gpio_chip
1435 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1436 * determined by a user supplied @match callback. The callback should return
1437 * 0 if the device doesn't match and non-zero if it does. If the callback is
1438 * non-zero, this function will return to the caller and not iterate over any
1441 struct gpio_chip *gpiochip_find(void *data,
1442 int (*match)(struct gpio_chip *chip,
1445 struct gpio_device *gdev;
1446 struct gpio_chip *chip = NULL;
1447 unsigned long flags;
1449 spin_lock_irqsave(&gpio_lock, flags);
1450 list_for_each_entry(gdev, &gpio_devices, list)
1451 if (gdev->chip && match(gdev->chip, data)) {
1456 spin_unlock_irqrestore(&gpio_lock, flags);
1460 EXPORT_SYMBOL_GPL(gpiochip_find);
1462 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1464 const char *name = data;
1466 return !strcmp(chip->label, name);
1469 static struct gpio_chip *find_chip_by_name(const char *name)
1471 return gpiochip_find((void *)name, gpiochip_match_name);
1474 #ifdef CONFIG_GPIOLIB_IRQCHIP
1477 * The following is irqchip helper code for gpiochips.
1480 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1484 if (!gpiochip->irq_need_valid_mask)
1487 gpiochip->irq_valid_mask = kcalloc(BITS_TO_LONGS(gpiochip->ngpio),
1488 sizeof(long), GFP_KERNEL);
1489 if (!gpiochip->irq_valid_mask)
1492 /* Assume by default all GPIOs are valid */
1493 for (i = 0; i < gpiochip->ngpio; i++)
1494 set_bit(i, gpiochip->irq_valid_mask);
1499 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1501 kfree(gpiochip->irq_valid_mask);
1502 gpiochip->irq_valid_mask = NULL;
1505 static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1506 unsigned int offset)
1508 /* No mask means all valid */
1509 if (likely(!gpiochip->irq_valid_mask))
1511 return test_bit(offset, gpiochip->irq_valid_mask);
1515 * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
1516 * @gpiochip: the gpiochip to set the irqchip chain to
1517 * @irqchip: the irqchip to chain to the gpiochip
1518 * @parent_irq: the irq number corresponding to the parent IRQ for this
1520 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1521 * coming out of the gpiochip. If the interrupt is nested rather than
1522 * cascaded, pass NULL in this handler argument
1524 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1525 struct irq_chip *irqchip,
1527 irq_flow_handler_t parent_handler)
1529 unsigned int offset;
1531 if (!gpiochip->irqdomain) {
1532 chip_err(gpiochip, "called %s before setting up irqchip\n",
1537 if (parent_handler) {
1538 if (gpiochip->can_sleep) {
1540 "you cannot have chained interrupts on a "
1541 "chip that may sleep\n");
1545 * The parent irqchip is already using the chip_data for this
1546 * irqchip, so our callbacks simply use the handler_data.
1548 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1551 gpiochip->irq_parent = parent_irq;
1554 /* Set the parent IRQ for all affected IRQs */
1555 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1556 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1558 irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
1562 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1565 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1566 * @d: the irqdomain used by this irqchip
1567 * @irq: the global irq number used by this GPIO irqchip irq
1568 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1570 * This function will set up the mapping for a certain IRQ line on a
1571 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1572 * stored inside the gpiochip.
1574 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1575 irq_hw_number_t hwirq)
1577 struct gpio_chip *chip = d->host_data;
1579 irq_set_chip_data(irq, chip);
1581 * This lock class tells lockdep that GPIO irqs are in a different
1582 * category than their parents, so it won't report false recursion.
1584 irq_set_lockdep_class(irq, chip->lock_key);
1585 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
1586 /* Chips that can sleep need nested thread handlers */
1587 if (chip->can_sleep && !chip->irq_not_threaded)
1588 irq_set_nested_thread(irq, 1);
1589 irq_set_noprobe(irq);
1592 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1593 * is passed as default type.
1595 if (chip->irq_default_type != IRQ_TYPE_NONE)
1596 irq_set_irq_type(irq, chip->irq_default_type);
1601 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1603 struct gpio_chip *chip = d->host_data;
1605 if (chip->can_sleep)
1606 irq_set_nested_thread(irq, 0);
1607 irq_set_chip_and_handler(irq, NULL, NULL);
1608 irq_set_chip_data(irq, NULL);
1611 static const struct irq_domain_ops gpiochip_domain_ops = {
1612 .map = gpiochip_irq_map,
1613 .unmap = gpiochip_irq_unmap,
1614 /* Virtually all GPIO irqchips are twocell:ed */
1615 .xlate = irq_domain_xlate_twocell,
1618 static int gpiochip_irq_reqres(struct irq_data *d)
1620 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1622 if (!try_module_get(chip->gpiodev->owner))
1625 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
1627 "unable to lock HW IRQ %lu for IRQ\n",
1629 module_put(chip->gpiodev->owner);
1635 static void gpiochip_irq_relres(struct irq_data *d)
1637 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1639 gpiochip_unlock_as_irq(chip, d->hwirq);
1640 module_put(chip->gpiodev->owner);
1643 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1645 return irq_find_mapping(chip->irqdomain, offset);
1649 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1650 * @gpiochip: the gpiochip to remove the irqchip from
1652 * This is called only from gpiochip_remove()
1654 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1656 unsigned int offset;
1658 acpi_gpiochip_free_interrupts(gpiochip);
1660 if (gpiochip->irq_parent) {
1661 irq_set_chained_handler(gpiochip->irq_parent, NULL);
1662 irq_set_handler_data(gpiochip->irq_parent, NULL);
1665 /* Remove all IRQ mappings and delete the domain */
1666 if (gpiochip->irqdomain) {
1667 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1668 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1670 irq_dispose_mapping(
1671 irq_find_mapping(gpiochip->irqdomain, offset));
1673 irq_domain_remove(gpiochip->irqdomain);
1676 if (gpiochip->irqchip) {
1677 gpiochip->irqchip->irq_request_resources = NULL;
1678 gpiochip->irqchip->irq_release_resources = NULL;
1679 gpiochip->irqchip = NULL;
1682 gpiochip_irqchip_free_valid_mask(gpiochip);
1686 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
1687 * @gpiochip: the gpiochip to add the irqchip to
1688 * @irqchip: the irqchip to add to the gpiochip
1689 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1690 * allocate gpiochip irqs from
1691 * @handler: the irq handler to use (often a predefined irq core function)
1692 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1693 * to have the core avoid setting up any default type in the hardware.
1694 * @lock_key: lockdep class
1696 * This function closely associates a certain irqchip with a certain
1697 * gpiochip, providing an irq domain to translate the local IRQs to
1698 * global irqs in the gpiolib core, and making sure that the gpiochip
1699 * is passed as chip data to all related functions. Driver callbacks
1700 * need to use gpiochip_get_data() to get their local state containers back
1701 * from the gpiochip passed as chip data. An irqdomain will be stored
1702 * in the gpiochip that shall be used by the driver to handle IRQ number
1703 * translation. The gpiochip will need to be initialized and registered
1704 * before calling this function.
1706 * This function will handle two cell:ed simple IRQs and assumes all
1707 * the pins on the gpiochip can generate a unique IRQ. Everything else
1708 * need to be open coded.
1710 int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
1711 struct irq_chip *irqchip,
1712 unsigned int first_irq,
1713 irq_flow_handler_t handler,
1715 struct lock_class_key *lock_key)
1717 struct device_node *of_node;
1718 bool irq_base_set = false;
1719 unsigned int offset;
1720 unsigned irq_base = 0;
1722 if (!gpiochip || !irqchip)
1725 if (!gpiochip->parent) {
1726 pr_err("missing gpiochip .dev parent pointer\n");
1729 of_node = gpiochip->parent->of_node;
1730 #ifdef CONFIG_OF_GPIO
1732 * If the gpiochip has an assigned OF node this takes precedence
1733 * FIXME: get rid of this and use gpiochip->parent->of_node
1736 if (gpiochip->of_node)
1737 of_node = gpiochip->of_node;
1740 * Specifying a default trigger is a terrible idea if DT or ACPI is
1741 * used to configure the interrupts, as you may end-up with
1742 * conflicting triggers. Tell the user, and reset to NONE.
1744 if (WARN(of_node && type != IRQ_TYPE_NONE,
1745 "%s: Ignoring %d default trigger\n", of_node->full_name, type))
1746 type = IRQ_TYPE_NONE;
1747 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1748 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1749 "Ignoring %d default trigger\n", type);
1750 type = IRQ_TYPE_NONE;
1753 gpiochip->irqchip = irqchip;
1754 gpiochip->irq_handler = handler;
1755 gpiochip->irq_default_type = type;
1756 gpiochip->to_irq = gpiochip_to_irq;
1757 gpiochip->lock_key = lock_key;
1758 gpiochip->irqdomain = irq_domain_add_simple(of_node,
1759 gpiochip->ngpio, first_irq,
1760 &gpiochip_domain_ops, gpiochip);
1761 if (!gpiochip->irqdomain) {
1762 gpiochip->irqchip = NULL;
1767 * It is possible for a driver to override this, but only if the
1768 * alternative functions are both implemented.
1770 if (!irqchip->irq_request_resources &&
1771 !irqchip->irq_release_resources) {
1772 irqchip->irq_request_resources = gpiochip_irq_reqres;
1773 irqchip->irq_release_resources = gpiochip_irq_relres;
1777 * Prepare the mapping since the irqchip shall be orthogonal to
1778 * any gpiochip calls. If the first_irq was zero, this is
1779 * necessary to allocate descriptors for all IRQs.
1781 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1782 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1784 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
1785 if (!irq_base_set) {
1787 * Store the base into the gpiochip to be used when
1788 * unmapping the irqs.
1790 gpiochip->irq_base = irq_base;
1791 irq_base_set = true;
1795 acpi_gpiochip_request_interrupts(gpiochip);
1799 EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add);
1801 #else /* CONFIG_GPIOLIB_IRQCHIP */
1803 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
1804 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1808 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1811 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1814 * gpiochip_generic_request() - request the gpio function for a pin
1815 * @chip: the gpiochip owning the GPIO
1816 * @offset: the offset of the GPIO to request for GPIO function
1818 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
1820 return pinctrl_request_gpio(chip->gpiodev->base + offset);
1822 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1825 * gpiochip_generic_free() - free the gpio function from a pin
1826 * @chip: the gpiochip to request the gpio function for
1827 * @offset: the offset of the GPIO to free from GPIO function
1829 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
1831 pinctrl_free_gpio(chip->gpiodev->base + offset);
1833 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1835 #ifdef CONFIG_PINCTRL
1838 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1839 * @chip: the gpiochip to add the range for
1840 * @pctldev: the pin controller to map to
1841 * @gpio_offset: the start offset in the current gpio_chip number space
1842 * @pin_group: name of the pin group inside the pin controller
1844 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
1845 struct pinctrl_dev *pctldev,
1846 unsigned int gpio_offset, const char *pin_group)
1848 struct gpio_pin_range *pin_range;
1849 struct gpio_device *gdev = chip->gpiodev;
1852 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1854 chip_err(chip, "failed to allocate pin ranges\n");
1858 /* Use local offset as range ID */
1859 pin_range->range.id = gpio_offset;
1860 pin_range->range.gc = chip;
1861 pin_range->range.name = chip->label;
1862 pin_range->range.base = gdev->base + gpio_offset;
1863 pin_range->pctldev = pctldev;
1865 ret = pinctrl_get_group_pins(pctldev, pin_group,
1866 &pin_range->range.pins,
1867 &pin_range->range.npins);
1873 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1875 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1876 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1877 pinctrl_dev_get_devname(pctldev), pin_group);
1879 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1883 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1886 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1887 * @chip: the gpiochip to add the range for
1888 * @pinctrl_name: the dev_name() of the pin controller to map to
1889 * @gpio_offset: the start offset in the current gpio_chip number space
1890 * @pin_offset: the start offset in the pin controller number space
1891 * @npins: the number of pins from the offset of each pin space (GPIO and
1892 * pin controller) to accumulate in this range
1894 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
1895 unsigned int gpio_offset, unsigned int pin_offset,
1898 struct gpio_pin_range *pin_range;
1899 struct gpio_device *gdev = chip->gpiodev;
1902 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1904 chip_err(chip, "failed to allocate pin ranges\n");
1908 /* Use local offset as range ID */
1909 pin_range->range.id = gpio_offset;
1910 pin_range->range.gc = chip;
1911 pin_range->range.name = chip->label;
1912 pin_range->range.base = gdev->base + gpio_offset;
1913 pin_range->range.pin_base = pin_offset;
1914 pin_range->range.npins = npins;
1915 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1917 if (IS_ERR(pin_range->pctldev)) {
1918 ret = PTR_ERR(pin_range->pctldev);
1919 chip_err(chip, "could not create pin range\n");
1923 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1924 gpio_offset, gpio_offset + npins - 1,
1926 pin_offset, pin_offset + npins - 1);
1928 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1932 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1935 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1936 * @chip: the chip to remove all the mappings for
1938 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
1940 struct gpio_pin_range *pin_range, *tmp;
1941 struct gpio_device *gdev = chip->gpiodev;
1943 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1944 list_del(&pin_range->node);
1945 pinctrl_remove_gpio_range(pin_range->pctldev,
1950 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1952 #endif /* CONFIG_PINCTRL */
1954 /* These "optional" allocation calls help prevent drivers from stomping
1955 * on each other, and help provide better diagnostics in debugfs.
1956 * They're called even less than the "set direction" calls.
1958 static int __gpiod_request(struct gpio_desc *desc, const char *label)
1960 struct gpio_chip *chip = desc->gdev->chip;
1962 unsigned long flags;
1964 spin_lock_irqsave(&gpio_lock, flags);
1966 /* NOTE: gpio_request() can be called in early boot,
1967 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1970 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1971 desc_set_label(desc, label ? : "?");
1978 if (chip->request) {
1979 /* chip->request may sleep */
1980 spin_unlock_irqrestore(&gpio_lock, flags);
1981 status = chip->request(chip, gpio_chip_hwgpio(desc));
1982 spin_lock_irqsave(&gpio_lock, flags);
1985 desc_set_label(desc, NULL);
1986 clear_bit(FLAG_REQUESTED, &desc->flags);
1990 if (chip->get_direction) {
1991 /* chip->get_direction may sleep */
1992 spin_unlock_irqrestore(&gpio_lock, flags);
1993 gpiod_get_direction(desc);
1994 spin_lock_irqsave(&gpio_lock, flags);
1997 spin_unlock_irqrestore(&gpio_lock, flags);
2002 * This descriptor validation needs to be inserted verbatim into each
2003 * function taking a descriptor, so we need to use a preprocessor
2004 * macro to avoid endless duplication. If the desc is NULL it is an
2005 * optional GPIO and calls should just bail out.
2007 #define VALIDATE_DESC(desc) do { \
2010 if (IS_ERR(desc)) { \
2011 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
2012 return PTR_ERR(desc); \
2014 if (!desc->gdev) { \
2015 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
2018 if ( !desc->gdev->chip ) { \
2019 dev_warn(&desc->gdev->dev, \
2020 "%s: backing chip is gone\n", __func__); \
2024 #define VALIDATE_DESC_VOID(desc) do { \
2027 if (IS_ERR(desc)) { \
2028 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
2031 if (!desc->gdev) { \
2032 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
2035 if (!desc->gdev->chip) { \
2036 dev_warn(&desc->gdev->dev, \
2037 "%s: backing chip is gone\n", __func__); \
2042 int gpiod_request(struct gpio_desc *desc, const char *label)
2044 int status = -EPROBE_DEFER;
2045 struct gpio_device *gdev;
2047 VALIDATE_DESC(desc);
2050 if (try_module_get(gdev->owner)) {
2051 status = __gpiod_request(desc, label);
2053 module_put(gdev->owner);
2055 get_device(&gdev->dev);
2059 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2064 static bool __gpiod_free(struct gpio_desc *desc)
2067 unsigned long flags;
2068 struct gpio_chip *chip;
2072 gpiod_unexport(desc);
2074 spin_lock_irqsave(&gpio_lock, flags);
2076 chip = desc->gdev->chip;
2077 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2079 spin_unlock_irqrestore(&gpio_lock, flags);
2080 might_sleep_if(chip->can_sleep);
2081 chip->free(chip, gpio_chip_hwgpio(desc));
2082 spin_lock_irqsave(&gpio_lock, flags);
2084 desc_set_label(desc, NULL);
2085 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2086 clear_bit(FLAG_REQUESTED, &desc->flags);
2087 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2088 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2089 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2093 spin_unlock_irqrestore(&gpio_lock, flags);
2097 void gpiod_free(struct gpio_desc *desc)
2099 if (desc && desc->gdev && __gpiod_free(desc)) {
2100 module_put(desc->gdev->owner);
2101 put_device(&desc->gdev->dev);
2103 WARN_ON(extra_checks);
2108 * gpiochip_is_requested - return string iff signal was requested
2109 * @chip: controller managing the signal
2110 * @offset: of signal within controller's 0..(ngpio - 1) range
2112 * Returns NULL if the GPIO is not currently requested, else a string.
2113 * The string returned is the label passed to gpio_request(); if none has been
2114 * passed it is a meaningless, non-NULL constant.
2116 * This function is for use by GPIO controller drivers. The label can
2117 * help with diagnostics, and knowing that the signal is used as a GPIO
2118 * can help avoid accidentally multiplexing it to another controller.
2120 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2122 struct gpio_desc *desc;
2124 if (offset >= chip->ngpio)
2127 desc = &chip->gpiodev->descs[offset];
2129 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2133 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2136 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2137 * @desc: GPIO descriptor to request
2138 * @label: label for the GPIO
2140 * Function allows GPIO chip drivers to request and use their own GPIO
2141 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2142 * function will not increase reference count of the GPIO chip module. This
2143 * allows the GPIO chip module to be unloaded as needed (we assume that the
2144 * GPIO chip driver handles freeing the GPIOs it has requested).
2146 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2149 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2153 chip_err(chip, "failed to get GPIO descriptor\n");
2157 err = __gpiod_request(desc, label);
2159 return ERR_PTR(err);
2163 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2166 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2167 * @desc: GPIO descriptor to free
2169 * Function frees the given GPIO requested previously with
2170 * gpiochip_request_own_desc().
2172 void gpiochip_free_own_desc(struct gpio_desc *desc)
2177 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2180 * Drivers MUST set GPIO direction before making get/set calls. In
2181 * some cases this is done in early boot, before IRQs are enabled.
2183 * As a rule these aren't called more than once (except for drivers
2184 * using the open-drain emulation idiom) so these are natural places
2185 * to accumulate extra debugging checks. Note that we can't (yet)
2186 * rely on gpio_request() having been called beforehand.
2190 * gpiod_direction_input - set the GPIO direction to input
2191 * @desc: GPIO to set to input
2193 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2194 * be called safely on it.
2196 * Return 0 in case of success, else an error code.
2198 int gpiod_direction_input(struct gpio_desc *desc)
2200 struct gpio_chip *chip;
2201 int status = -EINVAL;
2203 VALIDATE_DESC(desc);
2204 chip = desc->gdev->chip;
2206 if (!chip->get || !chip->direction_input) {
2208 "%s: missing get() or direction_input() operations\n",
2213 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2215 clear_bit(FLAG_IS_OUT, &desc->flags);
2217 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2221 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2223 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2225 struct gpio_chip *gc = desc->gdev->chip;
2228 /* GPIOs used for IRQs shall not be set as output */
2229 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
2231 "%s: tried to set a GPIO tied to an IRQ as output\n",
2236 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2237 /* First see if we can enable open drain in hardware */
2238 if (gc->set_single_ended) {
2239 ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
2240 LINE_MODE_OPEN_DRAIN);
2242 goto set_output_value;
2244 /* Emulate open drain by not actively driving the line high */
2246 return gpiod_direction_input(desc);
2248 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2249 if (gc->set_single_ended) {
2250 ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
2251 LINE_MODE_OPEN_SOURCE);
2253 goto set_output_value;
2255 /* Emulate open source by not actively driving the line low */
2257 return gpiod_direction_input(desc);
2259 /* Make sure to disable open drain/source hardware, if any */
2260 if (gc->set_single_ended)
2261 gc->set_single_ended(gc,
2262 gpio_chip_hwgpio(desc),
2263 LINE_MODE_PUSH_PULL);
2267 if (!gc->set || !gc->direction_output) {
2269 "%s: missing set() or direction_output() operations\n",
2274 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), value);
2276 set_bit(FLAG_IS_OUT, &desc->flags);
2277 trace_gpio_value(desc_to_gpio(desc), 0, value);
2278 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2283 * gpiod_direction_output_raw - set the GPIO direction to output
2284 * @desc: GPIO to set to output
2285 * @value: initial output value of the GPIO
2287 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2288 * be called safely on it. The initial value of the output must be specified
2289 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2291 * Return 0 in case of success, else an error code.
2293 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2295 VALIDATE_DESC(desc);
2296 return _gpiod_direction_output_raw(desc, value);
2298 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2301 * gpiod_direction_output - set the GPIO direction to output
2302 * @desc: GPIO to set to output
2303 * @value: initial output value of the GPIO
2305 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2306 * be called safely on it. The initial value of the output must be specified
2307 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2310 * Return 0 in case of success, else an error code.
2312 int gpiod_direction_output(struct gpio_desc *desc, int value)
2314 VALIDATE_DESC(desc);
2315 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2317 return _gpiod_direction_output_raw(desc, value);
2319 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2322 * gpiod_set_debounce - sets @debounce time for a @gpio
2323 * @gpio: the gpio to set debounce time
2324 * @debounce: debounce time is microseconds
2326 * returns -ENOTSUPP if the controller does not support setting
2329 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2331 struct gpio_chip *chip;
2333 VALIDATE_DESC(desc);
2334 chip = desc->gdev->chip;
2335 if (!chip->set || !chip->set_debounce) {
2337 "%s: missing set() or set_debounce() operations\n",
2342 return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);
2344 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2347 * gpiod_is_active_low - test whether a GPIO is active-low or not
2348 * @desc: the gpio descriptor to test
2350 * Returns 1 if the GPIO is active-low, 0 otherwise.
2352 int gpiod_is_active_low(const struct gpio_desc *desc)
2354 VALIDATE_DESC(desc);
2355 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2357 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2359 /* I/O calls are only valid after configuration completed; the relevant
2360 * "is this a valid GPIO" error checks should already have been done.
2362 * "Get" operations are often inlinable as reading a pin value register,
2363 * and masking the relevant bit in that register.
2365 * When "set" operations are inlinable, they involve writing that mask to
2366 * one register to set a low value, or a different register to set it high.
2367 * Otherwise locking is needed, so there may be little value to inlining.
2369 *------------------------------------------------------------------------
2371 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2372 * have requested the GPIO. That can include implicit requesting by
2373 * a direction setting call. Marking a gpio as requested locks its chip
2374 * in memory, guaranteeing that these table lookups need no more locking
2375 * and that gpiochip_remove() will fail.
2377 * REVISIT when debugging, consider adding some instrumentation to ensure
2378 * that the GPIO was actually requested.
2381 static int _gpiod_get_raw_value(const struct gpio_desc *desc)
2383 struct gpio_chip *chip;
2387 chip = desc->gdev->chip;
2388 offset = gpio_chip_hwgpio(desc);
2389 value = chip->get ? chip->get(chip, offset) : -EIO;
2390 value = value < 0 ? value : !!value;
2391 trace_gpio_value(desc_to_gpio(desc), 1, value);
2396 * gpiod_get_raw_value() - return a gpio's raw value
2397 * @desc: gpio whose value will be returned
2399 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2400 * its ACTIVE_LOW status, or negative errno on failure.
2402 * This function should be called from contexts where we cannot sleep, and will
2403 * complain if the GPIO chip functions potentially sleep.
2405 int gpiod_get_raw_value(const struct gpio_desc *desc)
2407 VALIDATE_DESC(desc);
2408 /* Should be using gpio_get_value_cansleep() */
2409 WARN_ON(desc->gdev->chip->can_sleep);
2410 return _gpiod_get_raw_value(desc);
2412 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2415 * gpiod_get_value() - return a gpio's value
2416 * @desc: gpio whose value will be returned
2418 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2419 * account, or negative errno on failure.
2421 * This function should be called from contexts where we cannot sleep, and will
2422 * complain if the GPIO chip functions potentially sleep.
2424 int gpiod_get_value(const struct gpio_desc *desc)
2428 VALIDATE_DESC(desc);
2429 /* Should be using gpio_get_value_cansleep() */
2430 WARN_ON(desc->gdev->chip->can_sleep);
2432 value = _gpiod_get_raw_value(desc);
2436 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2441 EXPORT_SYMBOL_GPL(gpiod_get_value);
2444 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
2445 * @desc: gpio descriptor whose state need to be set.
2446 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2448 static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
2451 struct gpio_chip *chip = desc->gdev->chip;
2452 int offset = gpio_chip_hwgpio(desc);
2455 err = chip->direction_input(chip, offset);
2457 clear_bit(FLAG_IS_OUT, &desc->flags);
2459 err = chip->direction_output(chip, offset, 0);
2461 set_bit(FLAG_IS_OUT, &desc->flags);
2463 trace_gpio_direction(desc_to_gpio(desc), value, err);
2466 "%s: Error in set_value for open drain err %d\n",
2471 * _gpio_set_open_source_value() - Set the open source gpio's value.
2472 * @desc: gpio descriptor whose state need to be set.
2473 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2475 static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
2478 struct gpio_chip *chip = desc->gdev->chip;
2479 int offset = gpio_chip_hwgpio(desc);
2482 err = chip->direction_output(chip, offset, 1);
2484 set_bit(FLAG_IS_OUT, &desc->flags);
2486 err = chip->direction_input(chip, offset);
2488 clear_bit(FLAG_IS_OUT, &desc->flags);
2490 trace_gpio_direction(desc_to_gpio(desc), !value, err);
2493 "%s: Error in set_value for open source err %d\n",
2497 static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
2499 struct gpio_chip *chip;
2501 chip = desc->gdev->chip;
2502 trace_gpio_value(desc_to_gpio(desc), 0, value);
2503 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
2504 _gpio_set_open_drain_value(desc, value);
2505 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
2506 _gpio_set_open_source_value(desc, value);
2508 chip->set(chip, gpio_chip_hwgpio(desc), value);
2512 * set multiple outputs on the same chip;
2513 * use the chip's set_multiple function if available;
2514 * otherwise set the outputs sequentially;
2515 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2516 * defines which outputs are to be changed
2517 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2518 * defines the values the outputs specified by mask are to be set to
2520 static void gpio_chip_set_multiple(struct gpio_chip *chip,
2521 unsigned long *mask, unsigned long *bits)
2523 if (chip->set_multiple) {
2524 chip->set_multiple(chip, mask, bits);
2527 for (i = 0; i < chip->ngpio; i++) {
2528 if (mask[BIT_WORD(i)] == 0) {
2529 /* no more set bits in this mask word;
2530 * skip ahead to the next word */
2531 i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1;
2534 /* set outputs if the corresponding mask bit is set */
2535 if (__test_and_clear_bit(i, mask))
2536 chip->set(chip, i, test_bit(i, bits));
2541 void gpiod_set_array_value_complex(bool raw, bool can_sleep,
2542 unsigned int array_size,
2543 struct gpio_desc **desc_array,
2548 while (i < array_size) {
2549 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2550 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
2551 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
2555 WARN_ON(chip->can_sleep);
2557 memset(mask, 0, sizeof(mask));
2559 struct gpio_desc *desc = desc_array[i];
2560 int hwgpio = gpio_chip_hwgpio(desc);
2561 int value = value_array[i];
2563 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2565 trace_gpio_value(desc_to_gpio(desc), 0, value);
2567 * collect all normal outputs belonging to the same chip
2568 * open drain and open source outputs are set individually
2570 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2571 _gpio_set_open_drain_value(desc, value);
2572 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2573 _gpio_set_open_source_value(desc, value);
2575 __set_bit(hwgpio, mask);
2577 __set_bit(hwgpio, bits);
2579 __clear_bit(hwgpio, bits);
2583 } while ((i < array_size) &&
2584 (desc_array[i]->gdev->chip == chip));
2585 /* push collected bits to outputs */
2587 gpio_chip_set_multiple(chip, mask, bits);
2592 * gpiod_set_raw_value() - assign a gpio's raw value
2593 * @desc: gpio whose value will be assigned
2594 * @value: value to assign
2596 * Set the raw value of the GPIO, i.e. the value of its physical line without
2597 * regard for its ACTIVE_LOW status.
2599 * This function should be called from contexts where we cannot sleep, and will
2600 * complain if the GPIO chip functions potentially sleep.
2602 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
2604 VALIDATE_DESC_VOID(desc);
2605 /* Should be using gpiod_set_value_cansleep() */
2606 WARN_ON(desc->gdev->chip->can_sleep);
2607 _gpiod_set_raw_value(desc, value);
2609 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
2612 * gpiod_set_value() - assign a gpio's value
2613 * @desc: gpio whose value will be assigned
2614 * @value: value to assign
2616 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2619 * This function should be called from contexts where we cannot sleep, and will
2620 * complain if the GPIO chip functions potentially sleep.
2622 void gpiod_set_value(struct gpio_desc *desc, int value)
2624 VALIDATE_DESC_VOID(desc);
2625 /* Should be using gpiod_set_value_cansleep() */
2626 WARN_ON(desc->gdev->chip->can_sleep);
2627 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2629 _gpiod_set_raw_value(desc, value);
2631 EXPORT_SYMBOL_GPL(gpiod_set_value);
2634 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
2635 * @array_size: number of elements in the descriptor / value arrays
2636 * @desc_array: array of GPIO descriptors whose values will be assigned
2637 * @value_array: array of values to assign
2639 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2640 * without regard for their ACTIVE_LOW status.
2642 * This function should be called from contexts where we cannot sleep, and will
2643 * complain if the GPIO chip functions potentially sleep.
2645 void gpiod_set_raw_array_value(unsigned int array_size,
2646 struct gpio_desc **desc_array, int *value_array)
2650 gpiod_set_array_value_complex(true, false, array_size, desc_array,
2653 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
2656 * gpiod_set_array_value() - assign values to an array of GPIOs
2657 * @array_size: number of elements in the descriptor / value arrays
2658 * @desc_array: array of GPIO descriptors whose values will be assigned
2659 * @value_array: array of values to assign
2661 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2664 * This function should be called from contexts where we cannot sleep, and will
2665 * complain if the GPIO chip functions potentially sleep.
2667 void gpiod_set_array_value(unsigned int array_size,
2668 struct gpio_desc **desc_array, int *value_array)
2672 gpiod_set_array_value_complex(false, false, array_size, desc_array,
2675 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
2678 * gpiod_cansleep() - report whether gpio value access may sleep
2679 * @desc: gpio to check
2682 int gpiod_cansleep(const struct gpio_desc *desc)
2684 VALIDATE_DESC(desc);
2685 return desc->gdev->chip->can_sleep;
2687 EXPORT_SYMBOL_GPL(gpiod_cansleep);
2690 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
2691 * @desc: gpio whose IRQ will be returned (already requested)
2693 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
2696 int gpiod_to_irq(const struct gpio_desc *desc)
2698 struct gpio_chip *chip;
2702 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
2703 * requires this function to not return zero on an invalid descriptor
2704 * but rather a negative error number.
2706 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
2709 chip = desc->gdev->chip;
2710 offset = gpio_chip_hwgpio(desc);
2712 int retirq = chip->to_irq(chip, offset);
2714 /* Zero means NO_IRQ */
2722 EXPORT_SYMBOL_GPL(gpiod_to_irq);
2725 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
2726 * @chip: the chip the GPIO to lock belongs to
2727 * @offset: the offset of the GPIO to lock as IRQ
2729 * This is used directly by GPIO drivers that want to lock down
2730 * a certain GPIO line to be used for IRQs.
2732 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
2734 struct gpio_desc *desc;
2736 desc = gpiochip_get_desc(chip, offset);
2738 return PTR_ERR(desc);
2740 /* Flush direction if something changed behind our back */
2741 if (chip->get_direction) {
2742 int dir = chip->get_direction(chip, offset);
2745 clear_bit(FLAG_IS_OUT, &desc->flags);
2747 set_bit(FLAG_IS_OUT, &desc->flags);
2750 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
2752 "%s: tried to flag a GPIO set as output for IRQ\n",
2757 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
2760 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
2763 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
2764 * @chip: the chip the GPIO to lock belongs to
2765 * @offset: the offset of the GPIO to lock as IRQ
2767 * This is used directly by GPIO drivers that want to indicate
2768 * that a certain GPIO is no longer used exclusively for IRQ.
2770 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
2772 if (offset >= chip->ngpio)
2775 clear_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2777 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
2779 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
2781 if (offset >= chip->ngpio)
2784 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2786 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
2788 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
2790 if (offset >= chip->ngpio)
2793 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
2795 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
2797 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
2799 if (offset >= chip->ngpio)
2802 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
2804 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
2807 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2808 * @desc: gpio whose value will be returned
2810 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2811 * its ACTIVE_LOW status, or negative errno on failure.
2813 * This function is to be called from contexts that can sleep.
2815 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
2817 might_sleep_if(extra_checks);
2818 VALIDATE_DESC(desc);
2819 return _gpiod_get_raw_value(desc);
2821 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
2824 * gpiod_get_value_cansleep() - return a gpio's value
2825 * @desc: gpio whose value will be returned
2827 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2828 * account, or negative errno on failure.
2830 * This function is to be called from contexts that can sleep.
2832 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
2836 might_sleep_if(extra_checks);
2837 VALIDATE_DESC(desc);
2838 value = _gpiod_get_raw_value(desc);
2842 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2847 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
2850 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2851 * @desc: gpio whose value will be assigned
2852 * @value: value to assign
2854 * Set the raw value of the GPIO, i.e. the value of its physical line without
2855 * regard for its ACTIVE_LOW status.
2857 * This function is to be called from contexts that can sleep.
2859 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
2861 might_sleep_if(extra_checks);
2862 VALIDATE_DESC_VOID(desc);
2863 _gpiod_set_raw_value(desc, value);
2865 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
2868 * gpiod_set_value_cansleep() - assign a gpio's value
2869 * @desc: gpio whose value will be assigned
2870 * @value: value to assign
2872 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2875 * This function is to be called from contexts that can sleep.
2877 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
2879 might_sleep_if(extra_checks);
2880 VALIDATE_DESC_VOID(desc);
2881 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2883 _gpiod_set_raw_value(desc, value);
2885 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
2888 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2889 * @array_size: number of elements in the descriptor / value arrays
2890 * @desc_array: array of GPIO descriptors whose values will be assigned
2891 * @value_array: array of values to assign
2893 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2894 * without regard for their ACTIVE_LOW status.
2896 * This function is to be called from contexts that can sleep.
2898 void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
2899 struct gpio_desc **desc_array,
2902 might_sleep_if(extra_checks);
2905 gpiod_set_array_value_complex(true, true, array_size, desc_array,
2908 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
2911 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2912 * @array_size: number of elements in the descriptor / value arrays
2913 * @desc_array: array of GPIO descriptors whose values will be assigned
2914 * @value_array: array of values to assign
2916 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2919 * This function is to be called from contexts that can sleep.
2921 void gpiod_set_array_value_cansleep(unsigned int array_size,
2922 struct gpio_desc **desc_array,
2925 might_sleep_if(extra_checks);
2928 gpiod_set_array_value_complex(false, true, array_size, desc_array,
2931 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
2934 * gpiod_add_lookup_table() - register GPIO device consumers
2935 * @table: table of consumers to register
2937 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
2939 mutex_lock(&gpio_lookup_lock);
2941 list_add_tail(&table->list, &gpio_lookup_list);
2943 mutex_unlock(&gpio_lookup_lock);
2947 * gpiod_remove_lookup_table() - unregister GPIO device consumers
2948 * @table: table of consumers to unregister
2950 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
2952 mutex_lock(&gpio_lookup_lock);
2954 list_del(&table->list);
2956 mutex_unlock(&gpio_lookup_lock);
2959 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
2961 const char *dev_id = dev ? dev_name(dev) : NULL;
2962 struct gpiod_lookup_table *table;
2964 mutex_lock(&gpio_lookup_lock);
2966 list_for_each_entry(table, &gpio_lookup_list, list) {
2967 if (table->dev_id && dev_id) {
2969 * Valid strings on both ends, must be identical to have
2972 if (!strcmp(table->dev_id, dev_id))
2976 * One of the pointers is NULL, so both must be to have
2979 if (dev_id == table->dev_id)
2986 mutex_unlock(&gpio_lookup_lock);
2990 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
2992 enum gpio_lookup_flags *flags)
2994 struct gpio_desc *desc = ERR_PTR(-ENOENT);
2995 struct gpiod_lookup_table *table;
2996 struct gpiod_lookup *p;
2998 table = gpiod_find_lookup_table(dev);
3002 for (p = &table->table[0]; p->chip_label; p++) {
3003 struct gpio_chip *chip;
3005 /* idx must always match exactly */
3009 /* If the lookup entry has a con_id, require exact match */
3010 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3013 chip = find_chip_by_name(p->chip_label);
3016 dev_err(dev, "cannot find GPIO chip %s\n",
3018 return ERR_PTR(-ENODEV);
3021 if (chip->ngpio <= p->chip_hwnum) {
3023 "requested GPIO %d is out of range [0..%d] for chip %s\n",
3024 idx, chip->ngpio, chip->label);
3025 return ERR_PTR(-EINVAL);
3028 desc = gpiochip_get_desc(chip, p->chip_hwnum);
3037 static int dt_gpio_count(struct device *dev, const char *con_id)
3043 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3045 snprintf(propname, sizeof(propname), "%s-%s",
3046 con_id, gpio_suffixes[i]);
3048 snprintf(propname, sizeof(propname), "%s",
3051 ret = of_gpio_named_count(dev->of_node, propname);
3058 static int platform_gpio_count(struct device *dev, const char *con_id)
3060 struct gpiod_lookup_table *table;
3061 struct gpiod_lookup *p;
3062 unsigned int count = 0;
3064 table = gpiod_find_lookup_table(dev);
3068 for (p = &table->table[0]; p->chip_label; p++) {
3069 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3070 (!con_id && !p->con_id))
3080 * gpiod_count - return the number of GPIOs associated with a device / function
3081 * or -ENOENT if no GPIO has been assigned to the requested function
3082 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3083 * @con_id: function within the GPIO consumer
3085 int gpiod_count(struct device *dev, const char *con_id)
3087 int count = -ENOENT;
3089 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
3090 count = dt_gpio_count(dev, con_id);
3091 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
3092 count = acpi_gpio_count(dev, con_id);
3095 count = platform_gpio_count(dev, con_id);
3099 EXPORT_SYMBOL_GPL(gpiod_count);
3102 * gpiod_get - obtain a GPIO for a given GPIO function
3103 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3104 * @con_id: function within the GPIO consumer
3105 * @flags: optional GPIO initialization flags
3107 * Return the GPIO descriptor corresponding to the function con_id of device
3108 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3109 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3111 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3112 enum gpiod_flags flags)
3114 return gpiod_get_index(dev, con_id, 0, flags);
3116 EXPORT_SYMBOL_GPL(gpiod_get);
3119 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3120 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3121 * @con_id: function within the GPIO consumer
3122 * @flags: optional GPIO initialization flags
3124 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3125 * the requested function it will return NULL. This is convenient for drivers
3126 * that need to handle optional GPIOs.
3128 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3130 enum gpiod_flags flags)
3132 return gpiod_get_index_optional(dev, con_id, 0, flags);
3134 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3138 * gpiod_configure_flags - helper function to configure a given GPIO
3139 * @desc: gpio whose value will be assigned
3140 * @con_id: function within the GPIO consumer
3141 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3143 * @dflags: gpiod_flags - optional GPIO initialization flags
3145 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3146 * requested function and/or index, or another IS_ERR() code if an error
3147 * occurred while trying to acquire the GPIO.
3149 static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3150 unsigned long lflags, enum gpiod_flags dflags)
3154 if (lflags & GPIO_ACTIVE_LOW)
3155 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3156 if (lflags & GPIO_OPEN_DRAIN)
3157 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3158 if (lflags & GPIO_OPEN_SOURCE)
3159 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3161 /* No particular flag request, return here... */
3162 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3163 pr_debug("no flags found for %s\n", con_id);
3168 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3169 status = gpiod_direction_output(desc,
3170 dflags & GPIOD_FLAGS_BIT_DIR_VAL);
3172 status = gpiod_direction_input(desc);
3178 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3179 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3180 * @con_id: function within the GPIO consumer
3181 * @idx: index of the GPIO to obtain in the consumer
3182 * @flags: optional GPIO initialization flags
3184 * This variant of gpiod_get() allows to access GPIOs other than the first
3185 * defined one for functions that define several GPIOs.
3187 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3188 * requested function and/or index, or another IS_ERR() code if an error
3189 * occurred while trying to acquire the GPIO.
3191 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3194 enum gpiod_flags flags)
3196 struct gpio_desc *desc = NULL;
3198 enum gpio_lookup_flags lookupflags = 0;
3200 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3203 /* Using device tree? */
3204 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
3205 dev_dbg(dev, "using device tree for GPIO lookup\n");
3206 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3207 } else if (ACPI_COMPANION(dev)) {
3208 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3209 desc = acpi_find_gpio(dev, con_id, idx, flags, &lookupflags);
3214 * Either we are not using DT or ACPI, or their lookup did not return
3215 * a result. In that case, use platform lookup as a fallback.
3217 if (!desc || desc == ERR_PTR(-ENOENT)) {
3218 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3219 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3223 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
3227 status = gpiod_request(desc, con_id);
3229 return ERR_PTR(status);
3231 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3233 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3235 return ERR_PTR(status);
3240 EXPORT_SYMBOL_GPL(gpiod_get_index);
3243 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3244 * @fwnode: handle of the firmware node
3245 * @propname: name of the firmware property representing the GPIO
3247 * This function can be used for drivers that get their configuration
3250 * Function properly finds the corresponding GPIO using whatever is the
3251 * underlying firmware interface and then makes sure that the GPIO
3252 * descriptor is requested before it is returned to the caller.
3254 * In case of error an ERR_PTR() is returned.
3256 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
3257 const char *propname)
3259 struct gpio_desc *desc = ERR_PTR(-ENODEV);
3260 bool active_low = false;
3261 bool single_ended = false;
3265 return ERR_PTR(-EINVAL);
3267 if (is_of_node(fwnode)) {
3268 enum of_gpio_flags flags;
3270 desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0,
3272 if (!IS_ERR(desc)) {
3273 active_low = flags & OF_GPIO_ACTIVE_LOW;
3274 single_ended = flags & OF_GPIO_SINGLE_ENDED;
3276 } else if (is_acpi_node(fwnode)) {
3277 struct acpi_gpio_info info;
3279 desc = acpi_node_get_gpiod(fwnode, propname, 0, &info);
3281 active_low = info.polarity == GPIO_ACTIVE_LOW;
3287 ret = gpiod_request(desc, NULL);
3289 return ERR_PTR(ret);
3292 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3296 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3298 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3303 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
3306 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
3308 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3309 * @con_id: function within the GPIO consumer
3310 * @index: index of the GPIO to obtain in the consumer
3311 * @flags: optional GPIO initialization flags
3313 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
3314 * specified index was assigned to the requested function it will return NULL.
3315 * This is convenient for drivers that need to handle optional GPIOs.
3317 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
3320 enum gpiod_flags flags)
3322 struct gpio_desc *desc;
3324 desc = gpiod_get_index(dev, con_id, index, flags);
3326 if (PTR_ERR(desc) == -ENOENT)
3332 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
3335 * gpiod_hog - Hog the specified GPIO desc given the provided flags
3336 * @desc: gpio whose value will be assigned
3337 * @name: gpio line name
3338 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3340 * @dflags: gpiod_flags - optional GPIO initialization flags
3342 int gpiod_hog(struct gpio_desc *desc, const char *name,
3343 unsigned long lflags, enum gpiod_flags dflags)
3345 struct gpio_chip *chip;
3346 struct gpio_desc *local_desc;
3350 chip = gpiod_to_chip(desc);
3351 hwnum = gpio_chip_hwgpio(desc);
3353 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
3354 if (IS_ERR(local_desc)) {
3355 status = PTR_ERR(local_desc);
3356 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
3357 name, chip->label, hwnum, status);
3361 status = gpiod_configure_flags(desc, name, lflags, dflags);
3363 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
3364 name, chip->label, hwnum, status);
3365 gpiochip_free_own_desc(desc);
3369 /* Mark GPIO as hogged so it can be identified and removed later */
3370 set_bit(FLAG_IS_HOGGED, &desc->flags);
3372 pr_info("GPIO line %d (%s) hogged as %s%s\n",
3373 desc_to_gpio(desc), name,
3374 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
3375 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
3376 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
3382 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
3383 * @chip: gpio chip to act on
3385 * This is only used by of_gpiochip_remove to free hogged gpios
3387 static void gpiochip_free_hogs(struct gpio_chip *chip)
3391 for (id = 0; id < chip->ngpio; id++) {
3392 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
3393 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
3398 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
3399 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3400 * @con_id: function within the GPIO consumer
3401 * @flags: optional GPIO initialization flags
3403 * This function acquires all the GPIOs defined under a given function.
3405 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
3406 * no GPIO has been assigned to the requested function, or another IS_ERR()
3407 * code if an error occurred while trying to acquire the GPIOs.
3409 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
3411 enum gpiod_flags flags)
3413 struct gpio_desc *desc;
3414 struct gpio_descs *descs;
3417 count = gpiod_count(dev, con_id);
3419 return ERR_PTR(count);
3421 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
3424 return ERR_PTR(-ENOMEM);
3426 for (descs->ndescs = 0; descs->ndescs < count; ) {
3427 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
3429 gpiod_put_array(descs);
3430 return ERR_CAST(desc);
3432 descs->desc[descs->ndescs] = desc;
3437 EXPORT_SYMBOL_GPL(gpiod_get_array);
3440 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
3442 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3443 * @con_id: function within the GPIO consumer
3444 * @flags: optional GPIO initialization flags
3446 * This is equivalent to gpiod_get_array(), except that when no GPIO was
3447 * assigned to the requested function it will return NULL.
3449 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
3451 enum gpiod_flags flags)
3453 struct gpio_descs *descs;
3455 descs = gpiod_get_array(dev, con_id, flags);
3456 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
3461 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
3464 * gpiod_put - dispose of a GPIO descriptor
3465 * @desc: GPIO descriptor to dispose of
3467 * No descriptor can be used after gpiod_put() has been called on it.
3469 void gpiod_put(struct gpio_desc *desc)
3473 EXPORT_SYMBOL_GPL(gpiod_put);
3476 * gpiod_put_array - dispose of multiple GPIO descriptors
3477 * @descs: struct gpio_descs containing an array of descriptors
3479 void gpiod_put_array(struct gpio_descs *descs)
3483 for (i = 0; i < descs->ndescs; i++)
3484 gpiod_put(descs->desc[i]);
3488 EXPORT_SYMBOL_GPL(gpiod_put_array);
3490 static int __init gpiolib_dev_init(void)
3494 /* Register GPIO sysfs bus */
3495 ret = bus_register(&gpio_bus_type);
3497 pr_err("gpiolib: could not register GPIO bus type\n");
3501 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
3503 pr_err("gpiolib: failed to allocate char dev region\n");
3504 bus_unregister(&gpio_bus_type);
3506 gpiolib_initialized = true;
3507 gpiochip_setup_devs();
3511 core_initcall(gpiolib_dev_init);
3513 #ifdef CONFIG_DEBUG_FS
3515 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
3518 struct gpio_chip *chip = gdev->chip;
3519 unsigned gpio = gdev->base;
3520 struct gpio_desc *gdesc = &gdev->descs[0];
3524 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
3525 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
3527 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
3533 gpiod_get_direction(gdesc);
3534 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
3535 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
3536 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
3537 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
3538 is_out ? "out" : "in ",
3540 ? (chip->get(chip, i) ? "hi" : "lo")
3542 is_irq ? "IRQ" : " ");
3543 seq_printf(s, "\n");
3547 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
3549 unsigned long flags;
3550 struct gpio_device *gdev = NULL;
3551 loff_t index = *pos;
3555 spin_lock_irqsave(&gpio_lock, flags);
3556 list_for_each_entry(gdev, &gpio_devices, list)
3558 spin_unlock_irqrestore(&gpio_lock, flags);
3561 spin_unlock_irqrestore(&gpio_lock, flags);
3566 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
3568 unsigned long flags;
3569 struct gpio_device *gdev = v;
3572 spin_lock_irqsave(&gpio_lock, flags);
3573 if (list_is_last(&gdev->list, &gpio_devices))
3576 ret = list_entry(gdev->list.next, struct gpio_device, list);
3577 spin_unlock_irqrestore(&gpio_lock, flags);
3585 static void gpiolib_seq_stop(struct seq_file *s, void *v)
3589 static int gpiolib_seq_show(struct seq_file *s, void *v)
3591 struct gpio_device *gdev = v;
3592 struct gpio_chip *chip = gdev->chip;
3593 struct device *parent;
3596 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
3597 dev_name(&gdev->dev));
3601 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
3602 dev_name(&gdev->dev),
3603 gdev->base, gdev->base + gdev->ngpio - 1);
3604 parent = chip->parent;
3606 seq_printf(s, ", parent: %s/%s",
3607 parent->bus ? parent->bus->name : "no-bus",
3610 seq_printf(s, ", %s", chip->label);
3611 if (chip->can_sleep)
3612 seq_printf(s, ", can sleep");
3613 seq_printf(s, ":\n");
3616 chip->dbg_show(s, chip);
3618 gpiolib_dbg_show(s, gdev);
3623 static const struct seq_operations gpiolib_seq_ops = {
3624 .start = gpiolib_seq_start,
3625 .next = gpiolib_seq_next,
3626 .stop = gpiolib_seq_stop,
3627 .show = gpiolib_seq_show,
3630 static int gpiolib_open(struct inode *inode, struct file *file)
3632 return seq_open(file, &gpiolib_seq_ops);
3635 static const struct file_operations gpiolib_operations = {
3636 .owner = THIS_MODULE,
3637 .open = gpiolib_open,
3639 .llseek = seq_lseek,
3640 .release = seq_release,
3643 static int __init gpiolib_debugfs_init(void)
3645 /* /sys/kernel/debug/gpio */
3646 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
3647 NULL, NULL, &gpiolib_operations);
3650 subsys_initcall(gpiolib_debugfs_init);
3652 #endif /* DEBUG_FS */