1 #include <linux/bitmap.h>
2 #include <linux/kernel.h>
3 #include <linux/module.h>
4 #include <linux/interrupt.h>
6 #include <linux/spinlock.h>
7 #include <linux/list.h>
8 #include <linux/device.h>
10 #include <linux/debugfs.h>
11 #include <linux/seq_file.h>
12 #include <linux/gpio.h>
13 #include <linux/of_gpio.h>
14 #include <linux/idr.h>
15 #include <linux/slab.h>
16 #include <linux/acpi.h>
17 #include <linux/gpio/driver.h>
18 #include <linux/gpio/machine.h>
19 #include <linux/pinctrl/consumer.h>
20 #include <linux/cdev.h>
22 #include <linux/uaccess.h>
23 #include <linux/compat.h>
24 #include <linux/anon_inodes.h>
25 #include <linux/file.h>
26 #include <linux/kfifo.h>
27 #include <linux/poll.h>
28 #include <linux/timekeeping.h>
29 #include <uapi/linux/gpio.h>
33 #define CREATE_TRACE_POINTS
34 #include <trace/events/gpio.h>
36 /* Implementation infrastructure for GPIO interfaces.
38 * The GPIO programming interface allows for inlining speed-critical
39 * get/set operations for common cases, so that access to SOC-integrated
40 * GPIOs can sometimes cost only an instruction or two per bit.
44 /* When debugging, extend minimal trust to callers and platform code.
45 * Also emit diagnostic messages that may help initial bringup, when
46 * board setup or driver bugs are most common.
48 * Otherwise, minimize overhead in what may be bitbanging codepaths.
51 #define extra_checks 1
53 #define extra_checks 0
56 /* Device and char device-related information */
57 static DEFINE_IDA(gpio_ida);
58 static dev_t gpio_devt;
59 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
60 static struct bus_type gpio_bus_type = {
64 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
65 * While any GPIO is requested, its gpio_chip is not removable;
66 * each GPIO's "requested" flag serves as a lock and refcount.
68 DEFINE_SPINLOCK(gpio_lock);
70 static DEFINE_MUTEX(gpio_lookup_lock);
71 static LIST_HEAD(gpio_lookup_list);
72 LIST_HEAD(gpio_devices);
74 static void gpiochip_free_hogs(struct gpio_chip *chip);
75 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
76 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
77 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
79 static bool gpiolib_initialized;
81 static inline void desc_set_label(struct gpio_desc *d, const char *label)
87 * Convert a GPIO number to its descriptor
89 struct gpio_desc *gpio_to_desc(unsigned gpio)
91 struct gpio_device *gdev;
94 spin_lock_irqsave(&gpio_lock, flags);
96 list_for_each_entry(gdev, &gpio_devices, list) {
97 if (gdev->base <= gpio &&
98 gdev->base + gdev->ngpio > gpio) {
99 spin_unlock_irqrestore(&gpio_lock, flags);
100 return &gdev->descs[gpio - gdev->base];
104 spin_unlock_irqrestore(&gpio_lock, flags);
106 if (!gpio_is_valid(gpio))
107 WARN(1, "invalid GPIO %d\n", gpio);
111 EXPORT_SYMBOL_GPL(gpio_to_desc);
114 * Get the GPIO descriptor corresponding to the given hw number for this chip.
116 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
119 struct gpio_device *gdev = chip->gpiodev;
121 if (hwnum >= gdev->ngpio)
122 return ERR_PTR(-EINVAL);
124 return &gdev->descs[hwnum];
128 * Convert a GPIO descriptor to the integer namespace.
129 * This should disappear in the future but is needed since we still
130 * use GPIO numbers for error messages and sysfs nodes
132 int desc_to_gpio(const struct gpio_desc *desc)
134 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
136 EXPORT_SYMBOL_GPL(desc_to_gpio);
140 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
141 * @desc: descriptor to return the chip of
143 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
145 if (!desc || !desc->gdev || !desc->gdev->chip)
147 return desc->gdev->chip;
149 EXPORT_SYMBOL_GPL(gpiod_to_chip);
151 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
152 static int gpiochip_find_base(int ngpio)
154 struct gpio_device *gdev;
155 int base = ARCH_NR_GPIOS - ngpio;
157 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
158 /* found a free space? */
159 if (gdev->base + gdev->ngpio <= base)
162 /* nope, check the space right before the chip */
163 base = gdev->base - ngpio;
166 if (gpio_is_valid(base)) {
167 pr_debug("%s: found new base at %d\n", __func__, base);
170 pr_err("%s: cannot find free range\n", __func__);
176 * gpiod_get_direction - return the current direction of a GPIO
177 * @desc: GPIO to get the direction of
179 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
181 * This function may sleep if gpiod_cansleep() is true.
183 int gpiod_get_direction(struct gpio_desc *desc)
185 struct gpio_chip *chip;
187 int status = -EINVAL;
189 chip = gpiod_to_chip(desc);
190 offset = gpio_chip_hwgpio(desc);
192 if (!chip->get_direction)
195 status = chip->get_direction(chip, offset);
197 /* GPIOF_DIR_IN, or other positive */
199 clear_bit(FLAG_IS_OUT, &desc->flags);
203 set_bit(FLAG_IS_OUT, &desc->flags);
207 EXPORT_SYMBOL_GPL(gpiod_get_direction);
210 * Add a new chip to the global chips list, keeping the list of chips sorted
211 * by range(means [base, base + ngpio - 1]) order.
213 * Return -EBUSY if the new chip overlaps with some other chip's integer
216 static int gpiodev_add_to_list(struct gpio_device *gdev)
218 struct gpio_device *prev, *next;
220 if (list_empty(&gpio_devices)) {
221 /* initial entry in list */
222 list_add_tail(&gdev->list, &gpio_devices);
226 next = list_entry(gpio_devices.next, struct gpio_device, list);
227 if (gdev->base + gdev->ngpio <= next->base) {
228 /* add before first entry */
229 list_add(&gdev->list, &gpio_devices);
233 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
234 if (prev->base + prev->ngpio <= gdev->base) {
235 /* add behind last entry */
236 list_add_tail(&gdev->list, &gpio_devices);
240 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
241 /* at the end of the list */
242 if (&next->list == &gpio_devices)
245 /* add between prev and next */
246 if (prev->base + prev->ngpio <= gdev->base
247 && gdev->base + gdev->ngpio <= next->base) {
248 list_add(&gdev->list, &prev->list);
253 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
258 * Convert a GPIO name to its descriptor
260 static struct gpio_desc *gpio_name_to_desc(const char * const name)
262 struct gpio_device *gdev;
265 spin_lock_irqsave(&gpio_lock, flags);
267 list_for_each_entry(gdev, &gpio_devices, list) {
270 for (i = 0; i != gdev->ngpio; ++i) {
271 struct gpio_desc *desc = &gdev->descs[i];
273 if (!desc->name || !name)
276 if (!strcmp(desc->name, name)) {
277 spin_unlock_irqrestore(&gpio_lock, flags);
283 spin_unlock_irqrestore(&gpio_lock, flags);
289 * Takes the names from gc->names and checks if they are all unique. If they
290 * are, they are assigned to their gpio descriptors.
292 * Warning if one of the names is already used for a different GPIO.
294 static int gpiochip_set_desc_names(struct gpio_chip *gc)
296 struct gpio_device *gdev = gc->gpiodev;
302 /* First check all names if they are unique */
303 for (i = 0; i != gc->ngpio; ++i) {
304 struct gpio_desc *gpio;
306 gpio = gpio_name_to_desc(gc->names[i]);
309 "Detected name collision for GPIO name '%s'\n",
313 /* Then add all names to the GPIO descriptors */
314 for (i = 0; i != gc->ngpio; ++i)
315 gdev->descs[i].name = gc->names[i];
321 * GPIO line handle management
325 * struct linehandle_state - contains the state of a userspace handle
326 * @gdev: the GPIO device the handle pertains to
327 * @label: consumer label used to tag descriptors
328 * @descs: the GPIO descriptors held by this handle
329 * @numdescs: the number of descriptors held in the descs array
331 struct linehandle_state {
332 struct gpio_device *gdev;
334 struct gpio_desc *descs[GPIOHANDLES_MAX];
338 #define GPIOHANDLE_REQUEST_VALID_FLAGS \
339 (GPIOHANDLE_REQUEST_INPUT | \
340 GPIOHANDLE_REQUEST_OUTPUT | \
341 GPIOHANDLE_REQUEST_ACTIVE_LOW | \
342 GPIOHANDLE_REQUEST_OPEN_DRAIN | \
343 GPIOHANDLE_REQUEST_OPEN_SOURCE)
345 static long linehandle_ioctl(struct file *filep, unsigned int cmd,
348 struct linehandle_state *lh = filep->private_data;
349 void __user *ip = (void __user *)arg;
350 struct gpiohandle_data ghd;
353 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
356 memset(&ghd, 0, sizeof(ghd));
358 /* TODO: check if descriptors are really input */
359 for (i = 0; i < lh->numdescs; i++) {
360 val = gpiod_get_value_cansleep(lh->descs[i]);
366 if (copy_to_user(ip, &ghd, sizeof(ghd)))
370 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
371 int vals[GPIOHANDLES_MAX];
373 /* TODO: check if descriptors are really output */
374 if (copy_from_user(&ghd, ip, sizeof(ghd)))
377 /* Clamp all values to [0,1] */
378 for (i = 0; i < lh->numdescs; i++)
379 vals[i] = !!ghd.values[i];
381 /* Reuse the array setting function */
382 gpiod_set_array_value_complex(false,
393 static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
396 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
400 static int linehandle_release(struct inode *inode, struct file *filep)
402 struct linehandle_state *lh = filep->private_data;
403 struct gpio_device *gdev = lh->gdev;
406 for (i = 0; i < lh->numdescs; i++)
407 gpiod_free(lh->descs[i]);
410 put_device(&gdev->dev);
414 static const struct file_operations linehandle_fileops = {
415 .release = linehandle_release,
416 .owner = THIS_MODULE,
417 .llseek = noop_llseek,
418 .unlocked_ioctl = linehandle_ioctl,
420 .compat_ioctl = linehandle_ioctl_compat,
424 static int linehandle_create(struct gpio_device *gdev, void __user *ip)
426 struct gpiohandle_request handlereq;
427 struct linehandle_state *lh;
431 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
433 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
436 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
440 get_device(&gdev->dev);
442 /* Make sure this is terminated */
443 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
444 if (strlen(handlereq.consumer_label)) {
445 lh->label = kstrdup(handlereq.consumer_label,
453 /* Request each GPIO */
454 for (i = 0; i < handlereq.lines; i++) {
455 u32 offset = handlereq.lineoffsets[i];
456 u32 lflags = handlereq.flags;
457 struct gpio_desc *desc;
459 if (offset >= gdev->ngpio) {
464 /* Return an error if a unknown flag is set */
465 if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) {
470 desc = &gdev->descs[offset];
471 ret = gpiod_request(desc, lh->label);
476 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
477 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
478 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
479 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
480 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
481 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
484 * Lines have to be requested explicitly for input
485 * or output, else the line will be treated "as is".
487 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
488 int val = !!handlereq.default_values[i];
490 ret = gpiod_direction_output(desc, val);
493 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
494 ret = gpiod_direction_input(desc);
498 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
501 /* Let i point at the last handle */
503 lh->numdescs = handlereq.lines;
505 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
511 file = anon_inode_getfile("gpio-linehandle",
514 O_RDONLY | O_CLOEXEC);
517 goto out_put_unused_fd;
521 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
523 * fput() will trigger the release() callback, so do not go onto
524 * the regular error cleanup path here.
531 fd_install(fd, file);
533 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
542 gpiod_free(lh->descs[i]);
546 put_device(&gdev->dev);
551 * GPIO line event management
555 * struct lineevent_state - contains the state of a userspace event
556 * @gdev: the GPIO device the event pertains to
557 * @label: consumer label used to tag descriptors
558 * @desc: the GPIO descriptor held by this event
559 * @eflags: the event flags this line was requested with
560 * @irq: the interrupt that trigger in response to events on this GPIO
561 * @wait: wait queue that handles blocking reads of events
562 * @events: KFIFO for the GPIO events
563 * @read_lock: mutex lock to protect reads from colliding with adding
564 * new events to the FIFO
566 struct lineevent_state {
567 struct gpio_device *gdev;
569 struct gpio_desc *desc;
572 wait_queue_head_t wait;
573 DECLARE_KFIFO(events, struct gpioevent_data, 16);
574 struct mutex read_lock;
577 #define GPIOEVENT_REQUEST_VALID_FLAGS \
578 (GPIOEVENT_REQUEST_RISING_EDGE | \
579 GPIOEVENT_REQUEST_FALLING_EDGE)
581 static unsigned int lineevent_poll(struct file *filep,
582 struct poll_table_struct *wait)
584 struct lineevent_state *le = filep->private_data;
585 unsigned int events = 0;
587 poll_wait(filep, &le->wait, wait);
589 if (!kfifo_is_empty(&le->events))
590 events = POLLIN | POLLRDNORM;
596 static ssize_t lineevent_read(struct file *filep,
601 struct lineevent_state *le = filep->private_data;
605 if (count < sizeof(struct gpioevent_data))
609 if (kfifo_is_empty(&le->events)) {
610 if (filep->f_flags & O_NONBLOCK)
613 ret = wait_event_interruptible(le->wait,
614 !kfifo_is_empty(&le->events));
619 if (mutex_lock_interruptible(&le->read_lock))
621 ret = kfifo_to_user(&le->events, buf, count, &copied);
622 mutex_unlock(&le->read_lock);
628 * If we couldn't read anything from the fifo (a different
629 * thread might have been faster) we either return -EAGAIN if
630 * the file descriptor is non-blocking, otherwise we go back to
631 * sleep and wait for more data to arrive.
633 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
636 } while (copied == 0);
641 static int lineevent_release(struct inode *inode, struct file *filep)
643 struct lineevent_state *le = filep->private_data;
644 struct gpio_device *gdev = le->gdev;
646 free_irq(le->irq, le);
647 gpiod_free(le->desc);
650 put_device(&gdev->dev);
654 static long lineevent_ioctl(struct file *filep, unsigned int cmd,
657 struct lineevent_state *le = filep->private_data;
658 void __user *ip = (void __user *)arg;
659 struct gpiohandle_data ghd;
662 * We can get the value for an event line but not set it,
663 * because it is input by definition.
665 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
668 memset(&ghd, 0, sizeof(ghd));
670 val = gpiod_get_value_cansleep(le->desc);
675 if (copy_to_user(ip, &ghd, sizeof(ghd)))
684 static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
687 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
691 static const struct file_operations lineevent_fileops = {
692 .release = lineevent_release,
693 .read = lineevent_read,
694 .poll = lineevent_poll,
695 .owner = THIS_MODULE,
696 .llseek = noop_llseek,
697 .unlocked_ioctl = lineevent_ioctl,
699 .compat_ioctl = lineevent_ioctl_compat,
703 static irqreturn_t lineevent_irq_thread(int irq, void *p)
705 struct lineevent_state *le = p;
706 struct gpioevent_data ge;
709 ge.timestamp = ktime_get_real_ns();
711 if (le->eflags & GPIOEVENT_REQUEST_BOTH_EDGES) {
712 int level = gpiod_get_value_cansleep(le->desc);
715 /* Emit low-to-high event */
716 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
718 /* Emit high-to-low event */
719 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
720 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
721 /* Emit low-to-high event */
722 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
723 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
724 /* Emit high-to-low event */
725 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
730 ret = kfifo_put(&le->events, ge);
732 wake_up_poll(&le->wait, POLLIN);
737 static int lineevent_create(struct gpio_device *gdev, void __user *ip)
739 struct gpioevent_request eventreq;
740 struct lineevent_state *le;
741 struct gpio_desc *desc;
750 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
753 le = kzalloc(sizeof(*le), GFP_KERNEL);
757 get_device(&gdev->dev);
759 /* Make sure this is terminated */
760 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
761 if (strlen(eventreq.consumer_label)) {
762 le->label = kstrdup(eventreq.consumer_label,
770 offset = eventreq.lineoffset;
771 lflags = eventreq.handleflags;
772 eflags = eventreq.eventflags;
774 if (offset >= gdev->ngpio) {
779 /* Return an error if a unknown flag is set */
780 if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
781 (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
786 /* This is just wrong: we don't look for events on output lines */
787 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
792 desc = &gdev->descs[offset];
793 ret = gpiod_request(desc, le->label);
799 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
800 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
801 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
802 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
803 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
804 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
806 ret = gpiod_direction_input(desc);
810 le->irq = gpiod_to_irq(desc);
816 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
817 irqflags |= IRQF_TRIGGER_RISING;
818 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
819 irqflags |= IRQF_TRIGGER_FALLING;
820 irqflags |= IRQF_ONESHOT;
821 irqflags |= IRQF_SHARED;
823 INIT_KFIFO(le->events);
824 init_waitqueue_head(&le->wait);
825 mutex_init(&le->read_lock);
827 /* Request a thread to read the events */
828 ret = request_threaded_irq(le->irq,
830 lineevent_irq_thread,
837 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
843 file = anon_inode_getfile("gpio-event",
846 O_RDONLY | O_CLOEXEC);
849 goto out_put_unused_fd;
853 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
855 * fput() will trigger the release() callback, so do not go onto
856 * the regular error cleanup path here.
863 fd_install(fd, file);
870 free_irq(le->irq, le);
872 gpiod_free(le->desc);
877 put_device(&gdev->dev);
882 * gpio_ioctl() - ioctl handler for the GPIO chardev
884 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
886 struct gpio_device *gdev = filp->private_data;
887 struct gpio_chip *chip = gdev->chip;
888 void __user *ip = (void __user *)arg;
890 /* We fail any subsequent ioctl():s when the chip is gone */
894 /* Fill in the struct and pass to userspace */
895 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
896 struct gpiochip_info chipinfo;
898 memset(&chipinfo, 0, sizeof(chipinfo));
900 strncpy(chipinfo.name, dev_name(&gdev->dev),
901 sizeof(chipinfo.name));
902 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
903 strncpy(chipinfo.label, gdev->label,
904 sizeof(chipinfo.label));
905 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
906 chipinfo.lines = gdev->ngpio;
907 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
910 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
911 struct gpioline_info lineinfo;
912 struct gpio_desc *desc;
914 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
916 if (lineinfo.line_offset >= gdev->ngpio)
919 desc = &gdev->descs[lineinfo.line_offset];
921 strncpy(lineinfo.name, desc->name,
922 sizeof(lineinfo.name));
923 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
925 lineinfo.name[0] = '\0';
928 strncpy(lineinfo.consumer, desc->label,
929 sizeof(lineinfo.consumer));
930 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
932 lineinfo.consumer[0] = '\0';
936 * Userspace only need to know that the kernel is using
937 * this GPIO so it can't use it.
940 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
941 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
942 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
943 test_bit(FLAG_EXPORT, &desc->flags) ||
944 test_bit(FLAG_SYSFS, &desc->flags))
945 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
946 if (test_bit(FLAG_IS_OUT, &desc->flags))
947 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
948 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
949 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
950 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
951 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
952 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
953 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
955 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
958 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
959 return linehandle_create(gdev, ip);
960 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
961 return lineevent_create(gdev, ip);
967 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
970 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
975 * gpio_chrdev_open() - open the chardev for ioctl operations
976 * @inode: inode for this chardev
977 * @filp: file struct for storing private data
978 * Returns 0 on success
980 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
982 struct gpio_device *gdev = container_of(inode->i_cdev,
983 struct gpio_device, chrdev);
985 /* Fail on open if the backing gpiochip is gone */
988 get_device(&gdev->dev);
989 filp->private_data = gdev;
991 return nonseekable_open(inode, filp);
995 * gpio_chrdev_release() - close chardev after ioctl operations
996 * @inode: inode for this chardev
997 * @filp: file struct for storing private data
998 * Returns 0 on success
1000 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1002 struct gpio_device *gdev = container_of(inode->i_cdev,
1003 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 = no_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->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1040 status = cdev_device_add(&gdev->chrdev, &gdev->dev);
1044 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1045 MAJOR(gpio_devt), gdev->id);
1047 status = gpiochip_sysfs_register(gdev);
1049 goto err_remove_device;
1051 /* From this point, the .release() function cleans up gpio_device */
1052 gdev->dev.release = gpiodevice_release;
1053 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1054 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1055 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1060 cdev_device_del(&gdev->chrdev, &gdev->dev);
1064 static void gpiochip_setup_devs(void)
1066 struct gpio_device *gdev;
1069 list_for_each_entry(gdev, &gpio_devices, list) {
1070 err = gpiochip_setup_dev(gdev);
1072 pr_err("%s: Failed to initialize gpio device (%d)\n",
1073 dev_name(&gdev->dev), err);
1078 * gpiochip_add_data() - register a gpio_chip
1079 * @chip: the chip to register, with chip->base initialized
1080 * Context: potentially before irqs will work
1082 * Returns a negative errno if the chip can't be registered, such as
1083 * because the chip->base is invalid or already associated with a
1084 * different chip. Otherwise it returns zero as a success code.
1086 * When gpiochip_add_data() is called very early during boot, so that GPIOs
1087 * can be freely used, the chip->parent device must be registered before
1088 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
1089 * for GPIOs will fail rudely.
1091 * gpiochip_add_data() must only be called after gpiolib initialization,
1092 * ie after core_initcall().
1094 * If chip->base is negative, this requests dynamic assignment of
1095 * a range of valid GPIOs.
1097 int gpiochip_add_data(struct gpio_chip *chip, void *data)
1099 unsigned long flags;
1102 int base = chip->base;
1103 struct gpio_device *gdev;
1106 * First: allocate and populate the internal stat container, and
1107 * set up the struct device.
1109 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1112 gdev->dev.bus = &gpio_bus_type;
1114 chip->gpiodev = gdev;
1116 gdev->dev.parent = chip->parent;
1117 gdev->dev.of_node = chip->parent->of_node;
1120 #ifdef CONFIG_OF_GPIO
1121 /* If the gpiochip has an assigned OF node this takes precedence */
1123 gdev->dev.of_node = chip->of_node;
1126 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1131 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1132 device_initialize(&gdev->dev);
1133 dev_set_drvdata(&gdev->dev, gdev);
1134 if (chip->parent && chip->parent->driver)
1135 gdev->owner = chip->parent->driver->owner;
1136 else if (chip->owner)
1137 /* TODO: remove chip->owner */
1138 gdev->owner = chip->owner;
1140 gdev->owner = THIS_MODULE;
1142 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1148 if (chip->ngpio == 0) {
1149 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1151 goto err_free_descs;
1155 gdev->label = kstrdup(chip->label, GFP_KERNEL);
1157 gdev->label = kstrdup("unknown", GFP_KERNEL);
1160 goto err_free_descs;
1163 gdev->ngpio = chip->ngpio;
1166 spin_lock_irqsave(&gpio_lock, flags);
1169 * TODO: this allocates a Linux GPIO number base in the global
1170 * GPIO numberspace for this chip. In the long run we want to
1171 * get *rid* of this numberspace and use only descriptors, but
1172 * it may be a pipe dream. It will not happen before we get rid
1173 * of the sysfs interface anyways.
1176 base = gpiochip_find_base(chip->ngpio);
1179 spin_unlock_irqrestore(&gpio_lock, flags);
1180 goto err_free_label;
1183 * TODO: it should not be necessary to reflect the assigned
1184 * base outside of the GPIO subsystem. Go over drivers and
1185 * see if anyone makes use of this, else drop this and assign
1192 status = gpiodev_add_to_list(gdev);
1194 spin_unlock_irqrestore(&gpio_lock, flags);
1195 goto err_free_label;
1198 spin_unlock_irqrestore(&gpio_lock, flags);
1200 for (i = 0; i < chip->ngpio; i++) {
1201 struct gpio_desc *desc = &gdev->descs[i];
1205 * REVISIT: most hardware initializes GPIOs as inputs
1206 * (often with pullups enabled) so power usage is
1207 * minimized. Linux code should set the gpio direction
1208 * first thing; but until it does, and in case
1209 * chip->get_direction is not set, we may expose the
1210 * wrong direction in sysfs.
1213 if (chip->get_direction) {
1215 * If we have .get_direction, set up the initial
1216 * direction flag from the hardware.
1218 int dir = chip->get_direction(chip, i);
1221 set_bit(FLAG_IS_OUT, &desc->flags);
1222 } else if (!chip->direction_input) {
1224 * If the chip lacks the .direction_input callback
1225 * we logically assume all lines are outputs.
1227 set_bit(FLAG_IS_OUT, &desc->flags);
1231 #ifdef CONFIG_PINCTRL
1232 INIT_LIST_HEAD(&gdev->pin_ranges);
1235 status = gpiochip_set_desc_names(chip);
1237 goto err_remove_from_list;
1239 status = gpiochip_irqchip_init_valid_mask(chip);
1241 goto err_remove_from_list;
1243 status = of_gpiochip_add(chip);
1245 goto err_remove_chip;
1247 acpi_gpiochip_add(chip);
1250 * By first adding the chardev, and then adding the device,
1251 * we get a device node entry in sysfs under
1252 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1253 * coldplug of device nodes and other udev business.
1254 * We can do this only if gpiolib has been initialized.
1255 * Otherwise, defer until later.
1257 if (gpiolib_initialized) {
1258 status = gpiochip_setup_dev(gdev);
1260 goto err_remove_chip;
1265 acpi_gpiochip_remove(chip);
1266 gpiochip_free_hogs(chip);
1267 of_gpiochip_remove(chip);
1268 gpiochip_irqchip_free_valid_mask(chip);
1269 err_remove_from_list:
1270 spin_lock_irqsave(&gpio_lock, flags);
1271 list_del(&gdev->list);
1272 spin_unlock_irqrestore(&gpio_lock, flags);
1278 ida_simple_remove(&gpio_ida, gdev->id);
1279 /* failures here can mean systems won't boot... */
1280 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
1281 gdev->base, gdev->base + gdev->ngpio - 1,
1282 chip->label ? : "generic");
1286 EXPORT_SYMBOL_GPL(gpiochip_add_data);
1289 * gpiochip_get_data() - get per-subdriver data for the chip
1291 void *gpiochip_get_data(struct gpio_chip *chip)
1293 return chip->gpiodev->data;
1295 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1298 * gpiochip_remove() - unregister a gpio_chip
1299 * @chip: the chip to unregister
1301 * A gpio_chip with any GPIOs still requested may not be removed.
1303 void gpiochip_remove(struct gpio_chip *chip)
1305 struct gpio_device *gdev = chip->gpiodev;
1306 struct gpio_desc *desc;
1307 unsigned long flags;
1309 bool requested = false;
1311 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1312 gpiochip_sysfs_unregister(gdev);
1313 gpiochip_free_hogs(chip);
1314 /* Numb the device, cancelling all outstanding operations */
1316 gpiochip_irqchip_remove(chip);
1317 acpi_gpiochip_remove(chip);
1318 gpiochip_remove_pin_ranges(chip);
1319 of_gpiochip_remove(chip);
1321 * We accept no more calls into the driver from this point, so
1322 * NULL the driver data pointer
1326 spin_lock_irqsave(&gpio_lock, flags);
1327 for (i = 0; i < gdev->ngpio; i++) {
1328 desc = &gdev->descs[i];
1329 if (test_bit(FLAG_REQUESTED, &desc->flags))
1332 spin_unlock_irqrestore(&gpio_lock, flags);
1335 dev_crit(&gdev->dev,
1336 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1339 * The gpiochip side puts its use of the device to rest here:
1340 * if there are no userspace clients, the chardev and device will
1341 * be removed, else it will be dangling until the last user is
1344 cdev_device_del(&gdev->chrdev, &gdev->dev);
1345 put_device(&gdev->dev);
1347 EXPORT_SYMBOL_GPL(gpiochip_remove);
1349 static void devm_gpio_chip_release(struct device *dev, void *res)
1351 struct gpio_chip *chip = *(struct gpio_chip **)res;
1353 gpiochip_remove(chip);
1356 static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
1359 struct gpio_chip **r = res;
1370 * devm_gpiochip_add_data() - Resource manager piochip_add_data()
1371 * @dev: the device pointer on which irq_chip belongs to.
1372 * @chip: the chip to register, with chip->base initialized
1373 * Context: potentially before irqs will work
1375 * Returns a negative errno if the chip can't be registered, such as
1376 * because the chip->base is invalid or already associated with a
1377 * different chip. Otherwise it returns zero as a success code.
1379 * The gpio chip automatically be released when the device is unbound.
1381 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1384 struct gpio_chip **ptr;
1387 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1392 ret = gpiochip_add_data(chip, data);
1399 devres_add(dev, ptr);
1403 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1406 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1407 * @dev: device for which which resource was allocated
1408 * @chip: the chip to remove
1410 * A gpio_chip with any GPIOs still requested may not be removed.
1412 void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
1416 ret = devres_release(dev, devm_gpio_chip_release,
1417 devm_gpio_chip_match, chip);
1420 EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
1423 * gpiochip_find() - iterator for locating a specific gpio_chip
1424 * @data: data to pass to match function
1425 * @callback: Callback function to check gpio_chip
1427 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1428 * determined by a user supplied @match callback. The callback should return
1429 * 0 if the device doesn't match and non-zero if it does. If the callback is
1430 * non-zero, this function will return to the caller and not iterate over any
1433 struct gpio_chip *gpiochip_find(void *data,
1434 int (*match)(struct gpio_chip *chip,
1437 struct gpio_device *gdev;
1438 struct gpio_chip *chip = NULL;
1439 unsigned long flags;
1441 spin_lock_irqsave(&gpio_lock, flags);
1442 list_for_each_entry(gdev, &gpio_devices, list)
1443 if (gdev->chip && match(gdev->chip, data)) {
1448 spin_unlock_irqrestore(&gpio_lock, flags);
1452 EXPORT_SYMBOL_GPL(gpiochip_find);
1454 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1456 const char *name = data;
1458 return !strcmp(chip->label, name);
1461 static struct gpio_chip *find_chip_by_name(const char *name)
1463 return gpiochip_find((void *)name, gpiochip_match_name);
1466 #ifdef CONFIG_GPIOLIB_IRQCHIP
1469 * The following is irqchip helper code for gpiochips.
1472 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1476 if (!gpiochip->irq_need_valid_mask)
1479 gpiochip->irq_valid_mask = kcalloc(BITS_TO_LONGS(gpiochip->ngpio),
1480 sizeof(long), GFP_KERNEL);
1481 if (!gpiochip->irq_valid_mask)
1484 /* Assume by default all GPIOs are valid */
1485 bitmap_fill(gpiochip->irq_valid_mask, gpiochip->ngpio);
1490 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1492 kfree(gpiochip->irq_valid_mask);
1493 gpiochip->irq_valid_mask = NULL;
1496 static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1497 unsigned int offset)
1499 /* No mask means all valid */
1500 if (likely(!gpiochip->irq_valid_mask))
1502 return test_bit(offset, gpiochip->irq_valid_mask);
1506 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1507 * @gpiochip: the gpiochip to set the irqchip chain to
1508 * @irqchip: the irqchip to chain to the gpiochip
1509 * @parent_irq: the irq number corresponding to the parent IRQ for this
1511 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1512 * coming out of the gpiochip. If the interrupt is nested rather than
1513 * cascaded, pass NULL in this handler argument
1515 static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
1516 struct irq_chip *irqchip,
1517 unsigned int parent_irq,
1518 irq_flow_handler_t parent_handler)
1520 unsigned int offset;
1522 if (!gpiochip->irqdomain) {
1523 chip_err(gpiochip, "called %s before setting up irqchip\n",
1528 if (parent_handler) {
1529 if (gpiochip->can_sleep) {
1531 "you cannot have chained interrupts on a "
1532 "chip that may sleep\n");
1536 * The parent irqchip is already using the chip_data for this
1537 * irqchip, so our callbacks simply use the handler_data.
1539 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1542 gpiochip->irq_chained_parent = parent_irq;
1545 /* Set the parent IRQ for all affected IRQs */
1546 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1547 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1549 irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
1555 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1556 * @gpiochip: the gpiochip to set the irqchip chain to
1557 * @irqchip: the irqchip to chain to the gpiochip
1558 * @parent_irq: the irq number corresponding to the parent IRQ for this
1560 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1561 * coming out of the gpiochip. If the interrupt is nested rather than
1562 * cascaded, pass NULL in this handler argument
1564 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1565 struct irq_chip *irqchip,
1566 unsigned int parent_irq,
1567 irq_flow_handler_t parent_handler)
1569 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1572 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1575 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1576 * @gpiochip: the gpiochip to set the irqchip nested handler to
1577 * @irqchip: the irqchip to nest to the gpiochip
1578 * @parent_irq: the irq number corresponding to the parent IRQ for this
1581 void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1582 struct irq_chip *irqchip,
1583 unsigned int parent_irq)
1585 if (!gpiochip->irq_nested) {
1586 chip_err(gpiochip, "tried to nest a chained gpiochip\n");
1589 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1592 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1595 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1596 * @d: the irqdomain used by this irqchip
1597 * @irq: the global irq number used by this GPIO irqchip irq
1598 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1600 * This function will set up the mapping for a certain IRQ line on a
1601 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1602 * stored inside the gpiochip.
1604 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1605 irq_hw_number_t hwirq)
1607 struct gpio_chip *chip = d->host_data;
1609 irq_set_chip_data(irq, chip);
1611 * This lock class tells lockdep that GPIO irqs are in a different
1612 * category than their parents, so it won't report false recursion.
1614 irq_set_lockdep_class(irq, chip->lock_key);
1615 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
1616 /* Chips that use nested thread handlers have them marked */
1617 if (chip->irq_nested)
1618 irq_set_nested_thread(irq, 1);
1619 irq_set_noprobe(irq);
1622 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1623 * is passed as default type.
1625 if (chip->irq_default_type != IRQ_TYPE_NONE)
1626 irq_set_irq_type(irq, chip->irq_default_type);
1631 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1633 struct gpio_chip *chip = d->host_data;
1635 if (chip->irq_nested)
1636 irq_set_nested_thread(irq, 0);
1637 irq_set_chip_and_handler(irq, NULL, NULL);
1638 irq_set_chip_data(irq, NULL);
1641 static const struct irq_domain_ops gpiochip_domain_ops = {
1642 .map = gpiochip_irq_map,
1643 .unmap = gpiochip_irq_unmap,
1644 /* Virtually all GPIO irqchips are twocell:ed */
1645 .xlate = irq_domain_xlate_twocell,
1648 static int gpiochip_irq_reqres(struct irq_data *d)
1650 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1652 if (!try_module_get(chip->gpiodev->owner))
1655 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
1657 "unable to lock HW IRQ %lu for IRQ\n",
1659 module_put(chip->gpiodev->owner);
1665 static void gpiochip_irq_relres(struct irq_data *d)
1667 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1669 gpiochip_unlock_as_irq(chip, d->hwirq);
1670 module_put(chip->gpiodev->owner);
1673 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1675 return irq_find_mapping(chip->irqdomain, offset);
1679 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1680 * @gpiochip: the gpiochip to remove the irqchip from
1682 * This is called only from gpiochip_remove()
1684 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1686 unsigned int offset;
1688 acpi_gpiochip_free_interrupts(gpiochip);
1690 if (gpiochip->irq_chained_parent) {
1691 irq_set_chained_handler(gpiochip->irq_chained_parent, NULL);
1692 irq_set_handler_data(gpiochip->irq_chained_parent, NULL);
1695 /* Remove all IRQ mappings and delete the domain */
1696 if (gpiochip->irqdomain) {
1697 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1698 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1700 irq_dispose_mapping(
1701 irq_find_mapping(gpiochip->irqdomain, offset));
1703 irq_domain_remove(gpiochip->irqdomain);
1706 if (gpiochip->irqchip) {
1707 gpiochip->irqchip->irq_request_resources = NULL;
1708 gpiochip->irqchip->irq_release_resources = NULL;
1709 gpiochip->irqchip = NULL;
1712 gpiochip_irqchip_free_valid_mask(gpiochip);
1716 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
1717 * @gpiochip: the gpiochip to add the irqchip to
1718 * @irqchip: the irqchip to add to the gpiochip
1719 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1720 * allocate gpiochip irqs from
1721 * @handler: the irq handler to use (often a predefined irq core function)
1722 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1723 * to have the core avoid setting up any default type in the hardware.
1724 * @nested: whether this is a nested irqchip calling handle_nested_irq()
1725 * in its IRQ handler
1726 * @lock_key: lockdep class
1728 * This function closely associates a certain irqchip with a certain
1729 * gpiochip, providing an irq domain to translate the local IRQs to
1730 * global irqs in the gpiolib core, and making sure that the gpiochip
1731 * is passed as chip data to all related functions. Driver callbacks
1732 * need to use gpiochip_get_data() to get their local state containers back
1733 * from the gpiochip passed as chip data. An irqdomain will be stored
1734 * in the gpiochip that shall be used by the driver to handle IRQ number
1735 * translation. The gpiochip will need to be initialized and registered
1736 * before calling this function.
1738 * This function will handle two cell:ed simple IRQs and assumes all
1739 * the pins on the gpiochip can generate a unique IRQ. Everything else
1740 * need to be open coded.
1742 int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
1743 struct irq_chip *irqchip,
1744 unsigned int first_irq,
1745 irq_flow_handler_t handler,
1748 struct lock_class_key *lock_key)
1750 struct device_node *of_node;
1751 bool irq_base_set = false;
1752 unsigned int offset;
1753 unsigned irq_base = 0;
1755 if (!gpiochip || !irqchip)
1758 if (!gpiochip->parent) {
1759 pr_err("missing gpiochip .dev parent pointer\n");
1762 gpiochip->irq_nested = nested;
1763 of_node = gpiochip->parent->of_node;
1764 #ifdef CONFIG_OF_GPIO
1766 * If the gpiochip has an assigned OF node this takes precedence
1767 * FIXME: get rid of this and use gpiochip->parent->of_node
1770 if (gpiochip->of_node)
1771 of_node = gpiochip->of_node;
1774 * Specifying a default trigger is a terrible idea if DT or ACPI is
1775 * used to configure the interrupts, as you may end-up with
1776 * conflicting triggers. Tell the user, and reset to NONE.
1778 if (WARN(of_node && type != IRQ_TYPE_NONE,
1779 "%s: Ignoring %d default trigger\n", of_node->full_name, type))
1780 type = IRQ_TYPE_NONE;
1781 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1782 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1783 "Ignoring %d default trigger\n", type);
1784 type = IRQ_TYPE_NONE;
1787 gpiochip->irqchip = irqchip;
1788 gpiochip->irq_handler = handler;
1789 gpiochip->irq_default_type = type;
1790 gpiochip->to_irq = gpiochip_to_irq;
1791 gpiochip->lock_key = lock_key;
1792 gpiochip->irqdomain = irq_domain_add_simple(of_node,
1793 gpiochip->ngpio, first_irq,
1794 &gpiochip_domain_ops, gpiochip);
1795 if (!gpiochip->irqdomain) {
1796 gpiochip->irqchip = NULL;
1801 * It is possible for a driver to override this, but only if the
1802 * alternative functions are both implemented.
1804 if (!irqchip->irq_request_resources &&
1805 !irqchip->irq_release_resources) {
1806 irqchip->irq_request_resources = gpiochip_irq_reqres;
1807 irqchip->irq_release_resources = gpiochip_irq_relres;
1811 * Prepare the mapping since the irqchip shall be orthogonal to
1812 * any gpiochip calls. If the first_irq was zero, this is
1813 * necessary to allocate descriptors for all IRQs.
1815 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1816 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1818 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
1819 if (!irq_base_set) {
1821 * Store the base into the gpiochip to be used when
1822 * unmapping the irqs.
1824 gpiochip->irq_base = irq_base;
1825 irq_base_set = true;
1829 acpi_gpiochip_request_interrupts(gpiochip);
1833 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
1835 #else /* CONFIG_GPIOLIB_IRQCHIP */
1837 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
1838 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1842 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1845 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1848 * gpiochip_generic_request() - request the gpio function for a pin
1849 * @chip: the gpiochip owning the GPIO
1850 * @offset: the offset of the GPIO to request for GPIO function
1852 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
1854 return pinctrl_request_gpio(chip->gpiodev->base + offset);
1856 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1859 * gpiochip_generic_free() - free the gpio function from a pin
1860 * @chip: the gpiochip to request the gpio function for
1861 * @offset: the offset of the GPIO to free from GPIO function
1863 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
1865 pinctrl_free_gpio(chip->gpiodev->base + offset);
1867 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1870 * gpiochip_generic_config() - apply configuration for a pin
1871 * @chip: the gpiochip owning the GPIO
1872 * @offset: the offset of the GPIO to apply the configuration
1873 * @config: the configuration to be applied
1875 int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
1876 unsigned long config)
1878 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
1880 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
1882 #ifdef CONFIG_PINCTRL
1885 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1886 * @chip: the gpiochip to add the range for
1887 * @pctldev: the pin controller to map to
1888 * @gpio_offset: the start offset in the current gpio_chip number space
1889 * @pin_group: name of the pin group inside the pin controller
1891 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
1892 struct pinctrl_dev *pctldev,
1893 unsigned int gpio_offset, const char *pin_group)
1895 struct gpio_pin_range *pin_range;
1896 struct gpio_device *gdev = chip->gpiodev;
1899 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1901 chip_err(chip, "failed to allocate pin ranges\n");
1905 /* Use local offset as range ID */
1906 pin_range->range.id = gpio_offset;
1907 pin_range->range.gc = chip;
1908 pin_range->range.name = chip->label;
1909 pin_range->range.base = gdev->base + gpio_offset;
1910 pin_range->pctldev = pctldev;
1912 ret = pinctrl_get_group_pins(pctldev, pin_group,
1913 &pin_range->range.pins,
1914 &pin_range->range.npins);
1920 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1922 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1923 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1924 pinctrl_dev_get_devname(pctldev), pin_group);
1926 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1930 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1933 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1934 * @chip: the gpiochip to add the range for
1935 * @pinctrl_name: the dev_name() of the pin controller to map to
1936 * @gpio_offset: the start offset in the current gpio_chip number space
1937 * @pin_offset: the start offset in the pin controller number space
1938 * @npins: the number of pins from the offset of each pin space (GPIO and
1939 * pin controller) to accumulate in this range
1941 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
1942 unsigned int gpio_offset, unsigned int pin_offset,
1945 struct gpio_pin_range *pin_range;
1946 struct gpio_device *gdev = chip->gpiodev;
1949 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1951 chip_err(chip, "failed to allocate pin ranges\n");
1955 /* Use local offset as range ID */
1956 pin_range->range.id = gpio_offset;
1957 pin_range->range.gc = chip;
1958 pin_range->range.name = chip->label;
1959 pin_range->range.base = gdev->base + gpio_offset;
1960 pin_range->range.pin_base = pin_offset;
1961 pin_range->range.npins = npins;
1962 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1964 if (IS_ERR(pin_range->pctldev)) {
1965 ret = PTR_ERR(pin_range->pctldev);
1966 chip_err(chip, "could not create pin range\n");
1970 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1971 gpio_offset, gpio_offset + npins - 1,
1973 pin_offset, pin_offset + npins - 1);
1975 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1979 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1982 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1983 * @chip: the chip to remove all the mappings for
1985 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
1987 struct gpio_pin_range *pin_range, *tmp;
1988 struct gpio_device *gdev = chip->gpiodev;
1990 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1991 list_del(&pin_range->node);
1992 pinctrl_remove_gpio_range(pin_range->pctldev,
1997 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1999 #endif /* CONFIG_PINCTRL */
2001 /* These "optional" allocation calls help prevent drivers from stomping
2002 * on each other, and help provide better diagnostics in debugfs.
2003 * They're called even less than the "set direction" calls.
2005 static int __gpiod_request(struct gpio_desc *desc, const char *label)
2007 struct gpio_chip *chip = desc->gdev->chip;
2009 unsigned long flags;
2011 spin_lock_irqsave(&gpio_lock, flags);
2013 /* NOTE: gpio_request() can be called in early boot,
2014 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2017 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2018 desc_set_label(desc, label ? : "?");
2025 if (chip->request) {
2026 /* chip->request may sleep */
2027 spin_unlock_irqrestore(&gpio_lock, flags);
2028 status = chip->request(chip, gpio_chip_hwgpio(desc));
2029 spin_lock_irqsave(&gpio_lock, flags);
2032 desc_set_label(desc, NULL);
2033 clear_bit(FLAG_REQUESTED, &desc->flags);
2037 if (chip->get_direction) {
2038 /* chip->get_direction may sleep */
2039 spin_unlock_irqrestore(&gpio_lock, flags);
2040 gpiod_get_direction(desc);
2041 spin_lock_irqsave(&gpio_lock, flags);
2044 spin_unlock_irqrestore(&gpio_lock, flags);
2049 * This descriptor validation needs to be inserted verbatim into each
2050 * function taking a descriptor, so we need to use a preprocessor
2051 * macro to avoid endless duplication. If the desc is NULL it is an
2052 * optional GPIO and calls should just bail out.
2054 #define VALIDATE_DESC(desc) do { \
2057 if (IS_ERR(desc)) { \
2058 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
2059 return PTR_ERR(desc); \
2061 if (!desc->gdev) { \
2062 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
2065 if ( !desc->gdev->chip ) { \
2066 dev_warn(&desc->gdev->dev, \
2067 "%s: backing chip is gone\n", __func__); \
2071 #define VALIDATE_DESC_VOID(desc) do { \
2074 if (IS_ERR(desc)) { \
2075 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
2078 if (!desc->gdev) { \
2079 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
2082 if (!desc->gdev->chip) { \
2083 dev_warn(&desc->gdev->dev, \
2084 "%s: backing chip is gone\n", __func__); \
2089 int gpiod_request(struct gpio_desc *desc, const char *label)
2091 int status = -EPROBE_DEFER;
2092 struct gpio_device *gdev;
2094 VALIDATE_DESC(desc);
2097 if (try_module_get(gdev->owner)) {
2098 status = __gpiod_request(desc, label);
2100 module_put(gdev->owner);
2102 get_device(&gdev->dev);
2106 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2111 static bool __gpiod_free(struct gpio_desc *desc)
2114 unsigned long flags;
2115 struct gpio_chip *chip;
2119 gpiod_unexport(desc);
2121 spin_lock_irqsave(&gpio_lock, flags);
2123 chip = desc->gdev->chip;
2124 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2126 spin_unlock_irqrestore(&gpio_lock, flags);
2127 might_sleep_if(chip->can_sleep);
2128 chip->free(chip, gpio_chip_hwgpio(desc));
2129 spin_lock_irqsave(&gpio_lock, flags);
2131 desc_set_label(desc, NULL);
2132 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2133 clear_bit(FLAG_REQUESTED, &desc->flags);
2134 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2135 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2136 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2140 spin_unlock_irqrestore(&gpio_lock, flags);
2144 void gpiod_free(struct gpio_desc *desc)
2146 if (desc && desc->gdev && __gpiod_free(desc)) {
2147 module_put(desc->gdev->owner);
2148 put_device(&desc->gdev->dev);
2150 WARN_ON(extra_checks);
2155 * gpiochip_is_requested - return string iff signal was requested
2156 * @chip: controller managing the signal
2157 * @offset: of signal within controller's 0..(ngpio - 1) range
2159 * Returns NULL if the GPIO is not currently requested, else a string.
2160 * The string returned is the label passed to gpio_request(); if none has been
2161 * passed it is a meaningless, non-NULL constant.
2163 * This function is for use by GPIO controller drivers. The label can
2164 * help with diagnostics, and knowing that the signal is used as a GPIO
2165 * can help avoid accidentally multiplexing it to another controller.
2167 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2169 struct gpio_desc *desc;
2171 if (offset >= chip->ngpio)
2174 desc = &chip->gpiodev->descs[offset];
2176 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2180 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2183 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2184 * @desc: GPIO descriptor to request
2185 * @label: label for the GPIO
2187 * Function allows GPIO chip drivers to request and use their own GPIO
2188 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2189 * function will not increase reference count of the GPIO chip module. This
2190 * allows the GPIO chip module to be unloaded as needed (we assume that the
2191 * GPIO chip driver handles freeing the GPIOs it has requested).
2193 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2196 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2200 chip_err(chip, "failed to get GPIO descriptor\n");
2204 err = __gpiod_request(desc, label);
2206 return ERR_PTR(err);
2210 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2213 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2214 * @desc: GPIO descriptor to free
2216 * Function frees the given GPIO requested previously with
2217 * gpiochip_request_own_desc().
2219 void gpiochip_free_own_desc(struct gpio_desc *desc)
2224 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2227 * Drivers MUST set GPIO direction before making get/set calls. In
2228 * some cases this is done in early boot, before IRQs are enabled.
2230 * As a rule these aren't called more than once (except for drivers
2231 * using the open-drain emulation idiom) so these are natural places
2232 * to accumulate extra debugging checks. Note that we can't (yet)
2233 * rely on gpio_request() having been called beforehand.
2237 * gpiod_direction_input - set the GPIO direction to input
2238 * @desc: GPIO to set to input
2240 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2241 * be called safely on it.
2243 * Return 0 in case of success, else an error code.
2245 int gpiod_direction_input(struct gpio_desc *desc)
2247 struct gpio_chip *chip;
2248 int status = -EINVAL;
2250 VALIDATE_DESC(desc);
2251 chip = desc->gdev->chip;
2253 if (!chip->get || !chip->direction_input) {
2255 "%s: missing get() or direction_input() operations\n",
2260 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2262 clear_bit(FLAG_IS_OUT, &desc->flags);
2264 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2268 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2270 static int gpio_set_drive_single_ended(struct gpio_chip *gc, unsigned offset,
2271 enum pin_config_param mode)
2273 unsigned long config = { PIN_CONF_PACKED(mode, 0) };
2275 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2278 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2280 struct gpio_chip *gc = desc->gdev->chip;
2284 /* GPIOs used for IRQs shall not be set as output */
2285 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
2287 "%s: tried to set a GPIO tied to an IRQ as output\n",
2292 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2293 /* First see if we can enable open drain in hardware */
2294 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2295 PIN_CONFIG_DRIVE_OPEN_DRAIN);
2297 goto set_output_value;
2298 /* Emulate open drain by not actively driving the line high */
2300 return gpiod_direction_input(desc);
2302 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2303 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2304 PIN_CONFIG_DRIVE_OPEN_SOURCE);
2306 goto set_output_value;
2307 /* Emulate open source by not actively driving the line low */
2309 return gpiod_direction_input(desc);
2311 gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2312 PIN_CONFIG_DRIVE_PUSH_PULL);
2316 if (!gc->set || !gc->direction_output) {
2318 "%s: missing set() or direction_output() operations\n",
2323 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2325 set_bit(FLAG_IS_OUT, &desc->flags);
2326 trace_gpio_value(desc_to_gpio(desc), 0, val);
2327 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2332 * gpiod_direction_output_raw - set the GPIO direction to output
2333 * @desc: GPIO to set to output
2334 * @value: initial output value of the GPIO
2336 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2337 * be called safely on it. The initial value of the output must be specified
2338 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2340 * Return 0 in case of success, else an error code.
2342 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2344 VALIDATE_DESC(desc);
2345 return _gpiod_direction_output_raw(desc, value);
2347 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2350 * gpiod_direction_output - set the GPIO direction to output
2351 * @desc: GPIO to set to output
2352 * @value: initial output value of the GPIO
2354 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2355 * be called safely on it. The initial value of the output must be specified
2356 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2359 * Return 0 in case of success, else an error code.
2361 int gpiod_direction_output(struct gpio_desc *desc, int value)
2363 VALIDATE_DESC(desc);
2364 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2368 return _gpiod_direction_output_raw(desc, value);
2370 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2373 * gpiod_set_debounce - sets @debounce time for a @gpio
2374 * @gpio: the gpio to set debounce time
2375 * @debounce: debounce time is microseconds
2377 * returns -ENOTSUPP if the controller does not support setting
2380 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2382 struct gpio_chip *chip;
2383 unsigned long config;
2385 VALIDATE_DESC(desc);
2386 chip = desc->gdev->chip;
2387 if (!chip->set || !chip->set_config) {
2389 "%s: missing set() or set_config() operations\n",
2394 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2395 return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
2397 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2400 * gpiod_is_active_low - test whether a GPIO is active-low or not
2401 * @desc: the gpio descriptor to test
2403 * Returns 1 if the GPIO is active-low, 0 otherwise.
2405 int gpiod_is_active_low(const struct gpio_desc *desc)
2407 VALIDATE_DESC(desc);
2408 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2410 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2412 /* I/O calls are only valid after configuration completed; the relevant
2413 * "is this a valid GPIO" error checks should already have been done.
2415 * "Get" operations are often inlinable as reading a pin value register,
2416 * and masking the relevant bit in that register.
2418 * When "set" operations are inlinable, they involve writing that mask to
2419 * one register to set a low value, or a different register to set it high.
2420 * Otherwise locking is needed, so there may be little value to inlining.
2422 *------------------------------------------------------------------------
2424 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2425 * have requested the GPIO. That can include implicit requesting by
2426 * a direction setting call. Marking a gpio as requested locks its chip
2427 * in memory, guaranteeing that these table lookups need no more locking
2428 * and that gpiochip_remove() will fail.
2430 * REVISIT when debugging, consider adding some instrumentation to ensure
2431 * that the GPIO was actually requested.
2434 static int _gpiod_get_raw_value(const struct gpio_desc *desc)
2436 struct gpio_chip *chip;
2440 chip = desc->gdev->chip;
2441 offset = gpio_chip_hwgpio(desc);
2442 value = chip->get ? chip->get(chip, offset) : -EIO;
2443 value = value < 0 ? value : !!value;
2444 trace_gpio_value(desc_to_gpio(desc), 1, value);
2449 * gpiod_get_raw_value() - return a gpio's raw value
2450 * @desc: gpio whose value will be returned
2452 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2453 * its ACTIVE_LOW status, or negative errno on failure.
2455 * This function should be called from contexts where we cannot sleep, and will
2456 * complain if the GPIO chip functions potentially sleep.
2458 int gpiod_get_raw_value(const struct gpio_desc *desc)
2460 VALIDATE_DESC(desc);
2461 /* Should be using gpio_get_value_cansleep() */
2462 WARN_ON(desc->gdev->chip->can_sleep);
2463 return _gpiod_get_raw_value(desc);
2465 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2468 * gpiod_get_value() - return a gpio's value
2469 * @desc: gpio whose value will be returned
2471 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2472 * account, or negative errno on failure.
2474 * This function should be called from contexts where we cannot sleep, and will
2475 * complain if the GPIO chip functions potentially sleep.
2477 int gpiod_get_value(const struct gpio_desc *desc)
2481 VALIDATE_DESC(desc);
2482 /* Should be using gpio_get_value_cansleep() */
2483 WARN_ON(desc->gdev->chip->can_sleep);
2485 value = _gpiod_get_raw_value(desc);
2489 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2494 EXPORT_SYMBOL_GPL(gpiod_get_value);
2497 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
2498 * @desc: gpio descriptor whose state need to be set.
2499 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2501 static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
2504 struct gpio_chip *chip = desc->gdev->chip;
2505 int offset = gpio_chip_hwgpio(desc);
2508 err = chip->direction_input(chip, offset);
2510 clear_bit(FLAG_IS_OUT, &desc->flags);
2512 err = chip->direction_output(chip, offset, 0);
2514 set_bit(FLAG_IS_OUT, &desc->flags);
2516 trace_gpio_direction(desc_to_gpio(desc), value, err);
2519 "%s: Error in set_value for open drain err %d\n",
2524 * _gpio_set_open_source_value() - Set the open source gpio's value.
2525 * @desc: gpio descriptor whose state need to be set.
2526 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2528 static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
2531 struct gpio_chip *chip = desc->gdev->chip;
2532 int offset = gpio_chip_hwgpio(desc);
2535 err = chip->direction_output(chip, offset, 1);
2537 set_bit(FLAG_IS_OUT, &desc->flags);
2539 err = chip->direction_input(chip, offset);
2541 clear_bit(FLAG_IS_OUT, &desc->flags);
2543 trace_gpio_direction(desc_to_gpio(desc), !value, err);
2546 "%s: Error in set_value for open source err %d\n",
2550 static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
2552 struct gpio_chip *chip;
2554 chip = desc->gdev->chip;
2555 trace_gpio_value(desc_to_gpio(desc), 0, value);
2556 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
2557 _gpio_set_open_drain_value(desc, value);
2558 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
2559 _gpio_set_open_source_value(desc, value);
2561 chip->set(chip, gpio_chip_hwgpio(desc), value);
2565 * set multiple outputs on the same chip;
2566 * use the chip's set_multiple function if available;
2567 * otherwise set the outputs sequentially;
2568 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2569 * defines which outputs are to be changed
2570 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2571 * defines the values the outputs specified by mask are to be set to
2573 static void gpio_chip_set_multiple(struct gpio_chip *chip,
2574 unsigned long *mask, unsigned long *bits)
2576 if (chip->set_multiple) {
2577 chip->set_multiple(chip, mask, bits);
2581 /* set outputs if the corresponding mask bit is set */
2582 for_each_set_bit(i, mask, chip->ngpio)
2583 chip->set(chip, i, test_bit(i, bits));
2587 void gpiod_set_array_value_complex(bool raw, bool can_sleep,
2588 unsigned int array_size,
2589 struct gpio_desc **desc_array,
2594 while (i < array_size) {
2595 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2596 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
2597 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
2601 WARN_ON(chip->can_sleep);
2603 memset(mask, 0, sizeof(mask));
2605 struct gpio_desc *desc = desc_array[i];
2606 int hwgpio = gpio_chip_hwgpio(desc);
2607 int value = value_array[i];
2609 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2611 trace_gpio_value(desc_to_gpio(desc), 0, value);
2613 * collect all normal outputs belonging to the same chip
2614 * open drain and open source outputs are set individually
2616 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2617 _gpio_set_open_drain_value(desc, value);
2618 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2619 _gpio_set_open_source_value(desc, value);
2621 __set_bit(hwgpio, mask);
2623 __set_bit(hwgpio, bits);
2625 __clear_bit(hwgpio, bits);
2629 } while ((i < array_size) &&
2630 (desc_array[i]->gdev->chip == chip));
2631 /* push collected bits to outputs */
2633 gpio_chip_set_multiple(chip, mask, bits);
2638 * gpiod_set_raw_value() - assign a gpio's raw value
2639 * @desc: gpio whose value will be assigned
2640 * @value: value to assign
2642 * Set the raw value of the GPIO, i.e. the value of its physical line without
2643 * regard for its ACTIVE_LOW status.
2645 * This function should be called from contexts where we cannot sleep, and will
2646 * complain if the GPIO chip functions potentially sleep.
2648 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
2650 VALIDATE_DESC_VOID(desc);
2651 /* Should be using gpiod_set_value_cansleep() */
2652 WARN_ON(desc->gdev->chip->can_sleep);
2653 _gpiod_set_raw_value(desc, value);
2655 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
2658 * gpiod_set_value() - assign a gpio's value
2659 * @desc: gpio whose value will be assigned
2660 * @value: value to assign
2662 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2665 * This function should be called from contexts where we cannot sleep, and will
2666 * complain if the GPIO chip functions potentially sleep.
2668 void gpiod_set_value(struct gpio_desc *desc, int value)
2670 VALIDATE_DESC_VOID(desc);
2671 /* Should be using gpiod_set_value_cansleep() */
2672 WARN_ON(desc->gdev->chip->can_sleep);
2673 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2675 _gpiod_set_raw_value(desc, value);
2677 EXPORT_SYMBOL_GPL(gpiod_set_value);
2680 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
2681 * @array_size: number of elements in the descriptor / value arrays
2682 * @desc_array: array of GPIO descriptors whose values will be assigned
2683 * @value_array: array of values to assign
2685 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2686 * without regard for their ACTIVE_LOW status.
2688 * This function should be called from contexts where we cannot sleep, and will
2689 * complain if the GPIO chip functions potentially sleep.
2691 void gpiod_set_raw_array_value(unsigned int array_size,
2692 struct gpio_desc **desc_array, int *value_array)
2696 gpiod_set_array_value_complex(true, false, array_size, desc_array,
2699 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
2702 * gpiod_set_array_value() - assign values to an array of GPIOs
2703 * @array_size: number of elements in the descriptor / value arrays
2704 * @desc_array: array of GPIO descriptors whose values will be assigned
2705 * @value_array: array of values to assign
2707 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2710 * This function should be called from contexts where we cannot sleep, and will
2711 * complain if the GPIO chip functions potentially sleep.
2713 void gpiod_set_array_value(unsigned int array_size,
2714 struct gpio_desc **desc_array, int *value_array)
2718 gpiod_set_array_value_complex(false, false, array_size, desc_array,
2721 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
2724 * gpiod_cansleep() - report whether gpio value access may sleep
2725 * @desc: gpio to check
2728 int gpiod_cansleep(const struct gpio_desc *desc)
2730 VALIDATE_DESC(desc);
2731 return desc->gdev->chip->can_sleep;
2733 EXPORT_SYMBOL_GPL(gpiod_cansleep);
2736 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
2737 * @desc: gpio whose IRQ will be returned (already requested)
2739 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
2742 int gpiod_to_irq(const struct gpio_desc *desc)
2744 struct gpio_chip *chip;
2748 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
2749 * requires this function to not return zero on an invalid descriptor
2750 * but rather a negative error number.
2752 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
2755 chip = desc->gdev->chip;
2756 offset = gpio_chip_hwgpio(desc);
2758 int retirq = chip->to_irq(chip, offset);
2760 /* Zero means NO_IRQ */
2768 EXPORT_SYMBOL_GPL(gpiod_to_irq);
2771 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
2772 * @chip: the chip the GPIO to lock belongs to
2773 * @offset: the offset of the GPIO to lock as IRQ
2775 * This is used directly by GPIO drivers that want to lock down
2776 * a certain GPIO line to be used for IRQs.
2778 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
2780 struct gpio_desc *desc;
2782 desc = gpiochip_get_desc(chip, offset);
2784 return PTR_ERR(desc);
2787 * If it's fast: flush the direction setting if something changed
2790 if (!chip->can_sleep && chip->get_direction) {
2791 int dir = chip->get_direction(chip, offset);
2794 clear_bit(FLAG_IS_OUT, &desc->flags);
2796 set_bit(FLAG_IS_OUT, &desc->flags);
2799 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
2801 "%s: tried to flag a GPIO set as output for IRQ\n",
2806 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
2809 * If the consumer has not set up a label (such as when the
2810 * IRQ is referenced from .to_irq()) we set up a label here
2811 * so it is clear this is used as an interrupt.
2814 desc_set_label(desc, "interrupt");
2818 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
2821 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
2822 * @chip: the chip the GPIO to lock belongs to
2823 * @offset: the offset of the GPIO to lock as IRQ
2825 * This is used directly by GPIO drivers that want to indicate
2826 * that a certain GPIO is no longer used exclusively for IRQ.
2828 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
2830 struct gpio_desc *desc;
2832 desc = gpiochip_get_desc(chip, offset);
2836 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
2838 /* If we only had this marking, erase it */
2839 if (desc->label && !strcmp(desc->label, "interrupt"))
2840 desc_set_label(desc, NULL);
2842 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
2844 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
2846 if (offset >= chip->ngpio)
2849 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2851 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
2853 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
2855 if (offset >= chip->ngpio)
2858 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
2860 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
2862 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
2864 if (offset >= chip->ngpio)
2867 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
2869 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
2871 bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
2873 if (offset >= chip->ngpio)
2876 return !test_bit(FLAG_SLEEP_MAY_LOOSE_VALUE,
2877 &chip->gpiodev->descs[offset].flags);
2879 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
2882 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2883 * @desc: gpio whose value will be returned
2885 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2886 * its ACTIVE_LOW status, or negative errno on failure.
2888 * This function is to be called from contexts that can sleep.
2890 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
2892 might_sleep_if(extra_checks);
2893 VALIDATE_DESC(desc);
2894 return _gpiod_get_raw_value(desc);
2896 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
2899 * gpiod_get_value_cansleep() - return a gpio's value
2900 * @desc: gpio whose value will be returned
2902 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2903 * account, or negative errno on failure.
2905 * This function is to be called from contexts that can sleep.
2907 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
2911 might_sleep_if(extra_checks);
2912 VALIDATE_DESC(desc);
2913 value = _gpiod_get_raw_value(desc);
2917 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2922 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
2925 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2926 * @desc: gpio whose value will be assigned
2927 * @value: value to assign
2929 * Set the raw value of the GPIO, i.e. the value of its physical line without
2930 * regard for its ACTIVE_LOW status.
2932 * This function is to be called from contexts that can sleep.
2934 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
2936 might_sleep_if(extra_checks);
2937 VALIDATE_DESC_VOID(desc);
2938 _gpiod_set_raw_value(desc, value);
2940 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
2943 * gpiod_set_value_cansleep() - assign a gpio's value
2944 * @desc: gpio whose value will be assigned
2945 * @value: value to assign
2947 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2950 * This function is to be called from contexts that can sleep.
2952 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
2954 might_sleep_if(extra_checks);
2955 VALIDATE_DESC_VOID(desc);
2956 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2958 _gpiod_set_raw_value(desc, value);
2960 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
2963 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2964 * @array_size: number of elements in the descriptor / value arrays
2965 * @desc_array: array of GPIO descriptors whose values will be assigned
2966 * @value_array: array of values to assign
2968 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2969 * without regard for their ACTIVE_LOW status.
2971 * This function is to be called from contexts that can sleep.
2973 void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
2974 struct gpio_desc **desc_array,
2977 might_sleep_if(extra_checks);
2980 gpiod_set_array_value_complex(true, true, array_size, desc_array,
2983 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
2986 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2987 * @array_size: number of elements in the descriptor / value arrays
2988 * @desc_array: array of GPIO descriptors whose values will be assigned
2989 * @value_array: array of values to assign
2991 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2994 * This function is to be called from contexts that can sleep.
2996 void gpiod_set_array_value_cansleep(unsigned int array_size,
2997 struct gpio_desc **desc_array,
3000 might_sleep_if(extra_checks);
3003 gpiod_set_array_value_complex(false, true, array_size, desc_array,
3006 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3009 * gpiod_add_lookup_table() - register GPIO device consumers
3010 * @table: table of consumers to register
3012 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3014 mutex_lock(&gpio_lookup_lock);
3016 list_add_tail(&table->list, &gpio_lookup_list);
3018 mutex_unlock(&gpio_lookup_lock);
3020 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3023 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3024 * @table: table of consumers to unregister
3026 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3028 mutex_lock(&gpio_lookup_lock);
3030 list_del(&table->list);
3032 mutex_unlock(&gpio_lookup_lock);
3034 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3036 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3038 const char *dev_id = dev ? dev_name(dev) : NULL;
3039 struct gpiod_lookup_table *table;
3041 mutex_lock(&gpio_lookup_lock);
3043 list_for_each_entry(table, &gpio_lookup_list, list) {
3044 if (table->dev_id && dev_id) {
3046 * Valid strings on both ends, must be identical to have
3049 if (!strcmp(table->dev_id, dev_id))
3053 * One of the pointers is NULL, so both must be to have
3056 if (dev_id == table->dev_id)
3063 mutex_unlock(&gpio_lookup_lock);
3067 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3069 enum gpio_lookup_flags *flags)
3071 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3072 struct gpiod_lookup_table *table;
3073 struct gpiod_lookup *p;
3075 table = gpiod_find_lookup_table(dev);
3079 for (p = &table->table[0]; p->chip_label; p++) {
3080 struct gpio_chip *chip;
3082 /* idx must always match exactly */
3086 /* If the lookup entry has a con_id, require exact match */
3087 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3090 chip = find_chip_by_name(p->chip_label);
3093 dev_err(dev, "cannot find GPIO chip %s\n",
3095 return ERR_PTR(-ENODEV);
3098 if (chip->ngpio <= p->chip_hwnum) {
3100 "requested GPIO %d is out of range [0..%d] for chip %s\n",
3101 idx, chip->ngpio, chip->label);
3102 return ERR_PTR(-EINVAL);
3105 desc = gpiochip_get_desc(chip, p->chip_hwnum);
3114 static int dt_gpio_count(struct device *dev, const char *con_id)
3120 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3122 snprintf(propname, sizeof(propname), "%s-%s",
3123 con_id, gpio_suffixes[i]);
3125 snprintf(propname, sizeof(propname), "%s",
3128 ret = of_gpio_named_count(dev->of_node, propname);
3132 return ret ? ret : -ENOENT;
3135 static int platform_gpio_count(struct device *dev, const char *con_id)
3137 struct gpiod_lookup_table *table;
3138 struct gpiod_lookup *p;
3139 unsigned int count = 0;
3141 table = gpiod_find_lookup_table(dev);
3145 for (p = &table->table[0]; p->chip_label; p++) {
3146 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3147 (!con_id && !p->con_id))
3157 * gpiod_count - return the number of GPIOs associated with a device / function
3158 * or -ENOENT if no GPIO has been assigned to the requested function
3159 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3160 * @con_id: function within the GPIO consumer
3162 int gpiod_count(struct device *dev, const char *con_id)
3164 int count = -ENOENT;
3166 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
3167 count = dt_gpio_count(dev, con_id);
3168 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
3169 count = acpi_gpio_count(dev, con_id);
3172 count = platform_gpio_count(dev, con_id);
3176 EXPORT_SYMBOL_GPL(gpiod_count);
3179 * gpiod_get - obtain a GPIO for a given GPIO function
3180 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3181 * @con_id: function within the GPIO consumer
3182 * @flags: optional GPIO initialization flags
3184 * Return the GPIO descriptor corresponding to the function con_id of device
3185 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3186 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3188 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3189 enum gpiod_flags flags)
3191 return gpiod_get_index(dev, con_id, 0, flags);
3193 EXPORT_SYMBOL_GPL(gpiod_get);
3196 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3197 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3198 * @con_id: function within the GPIO consumer
3199 * @flags: optional GPIO initialization flags
3201 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3202 * the requested function it will return NULL. This is convenient for drivers
3203 * that need to handle optional GPIOs.
3205 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3207 enum gpiod_flags flags)
3209 return gpiod_get_index_optional(dev, con_id, 0, flags);
3211 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3215 * gpiod_configure_flags - helper function to configure a given GPIO
3216 * @desc: gpio whose value will be assigned
3217 * @con_id: function within the GPIO consumer
3218 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3220 * @dflags: gpiod_flags - optional GPIO initialization flags
3222 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3223 * requested function and/or index, or another IS_ERR() code if an error
3224 * occurred while trying to acquire the GPIO.
3226 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3227 unsigned long lflags, enum gpiod_flags dflags)
3231 if (lflags & GPIO_ACTIVE_LOW)
3232 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3233 if (lflags & GPIO_OPEN_DRAIN)
3234 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3235 if (lflags & GPIO_OPEN_SOURCE)
3236 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3237 if (lflags & GPIO_SLEEP_MAY_LOOSE_VALUE)
3238 set_bit(FLAG_SLEEP_MAY_LOOSE_VALUE, &desc->flags);
3240 /* No particular flag request, return here... */
3241 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3242 pr_debug("no flags found for %s\n", con_id);
3247 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3248 status = gpiod_direction_output(desc,
3249 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3251 status = gpiod_direction_input(desc);
3257 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3258 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3259 * @con_id: function within the GPIO consumer
3260 * @idx: index of the GPIO to obtain in the consumer
3261 * @flags: optional GPIO initialization flags
3263 * This variant of gpiod_get() allows to access GPIOs other than the first
3264 * defined one for functions that define several GPIOs.
3266 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3267 * requested function and/or index, or another IS_ERR() code if an error
3268 * occurred while trying to acquire the GPIO.
3270 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3273 enum gpiod_flags flags)
3275 struct gpio_desc *desc = NULL;
3277 enum gpio_lookup_flags lookupflags = 0;
3279 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3282 /* Using device tree? */
3283 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
3284 dev_dbg(dev, "using device tree for GPIO lookup\n");
3285 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3286 } else if (ACPI_COMPANION(dev)) {
3287 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3288 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
3293 * Either we are not using DT or ACPI, or their lookup did not return
3294 * a result. In that case, use platform lookup as a fallback.
3296 if (!desc || desc == ERR_PTR(-ENOENT)) {
3297 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3298 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3302 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
3306 status = gpiod_request(desc, con_id);
3308 return ERR_PTR(status);
3310 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3312 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3314 return ERR_PTR(status);
3319 EXPORT_SYMBOL_GPL(gpiod_get_index);
3322 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3323 * @fwnode: handle of the firmware node
3324 * @propname: name of the firmware property representing the GPIO
3325 * @index: index of the GPIO to obtain in the consumer
3326 * @dflags: GPIO initialization flags
3328 * This function can be used for drivers that get their configuration
3331 * Function properly finds the corresponding GPIO using whatever is the
3332 * underlying firmware interface and then makes sure that the GPIO
3333 * descriptor is requested before it is returned to the caller.
3335 * On successful request the GPIO pin is configured in accordance with
3338 * In case of error an ERR_PTR() is returned.
3340 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
3341 const char *propname, int index,
3342 enum gpiod_flags dflags,
3345 struct gpio_desc *desc = ERR_PTR(-ENODEV);
3346 unsigned long lflags = 0;
3347 bool active_low = false;
3348 bool single_ended = false;
3349 bool open_drain = false;
3353 return ERR_PTR(-EINVAL);
3355 if (is_of_node(fwnode)) {
3356 enum of_gpio_flags flags;
3358 desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname,
3360 if (!IS_ERR(desc)) {
3361 active_low = flags & OF_GPIO_ACTIVE_LOW;
3362 single_ended = flags & OF_GPIO_SINGLE_ENDED;
3363 open_drain = flags & OF_GPIO_OPEN_DRAIN;
3365 } else if (is_acpi_node(fwnode)) {
3366 struct acpi_gpio_info info;
3368 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
3369 if (!IS_ERR(desc)) {
3370 active_low = info.polarity == GPIO_ACTIVE_LOW;
3371 ret = acpi_gpio_update_gpiod_flags(&dflags, info.flags);
3373 pr_debug("Override GPIO initialization flags\n");
3380 ret = gpiod_request(desc, label);
3382 return ERR_PTR(ret);
3385 lflags |= GPIO_ACTIVE_LOW;
3389 lflags |= GPIO_OPEN_DRAIN;
3391 lflags |= GPIO_OPEN_SOURCE;
3394 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
3397 return ERR_PTR(ret);
3402 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
3405 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
3407 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3408 * @con_id: function within the GPIO consumer
3409 * @index: index of the GPIO to obtain in the consumer
3410 * @flags: optional GPIO initialization flags
3412 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
3413 * specified index was assigned to the requested function it will return NULL.
3414 * This is convenient for drivers that need to handle optional GPIOs.
3416 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
3419 enum gpiod_flags flags)
3421 struct gpio_desc *desc;
3423 desc = gpiod_get_index(dev, con_id, index, flags);
3425 if (PTR_ERR(desc) == -ENOENT)
3431 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
3434 * gpiod_hog - Hog the specified GPIO desc given the provided flags
3435 * @desc: gpio whose value will be assigned
3436 * @name: gpio line name
3437 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3439 * @dflags: gpiod_flags - optional GPIO initialization flags
3441 int gpiod_hog(struct gpio_desc *desc, const char *name,
3442 unsigned long lflags, enum gpiod_flags dflags)
3444 struct gpio_chip *chip;
3445 struct gpio_desc *local_desc;
3449 chip = gpiod_to_chip(desc);
3450 hwnum = gpio_chip_hwgpio(desc);
3452 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
3453 if (IS_ERR(local_desc)) {
3454 status = PTR_ERR(local_desc);
3455 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
3456 name, chip->label, hwnum, status);
3460 status = gpiod_configure_flags(desc, name, lflags, dflags);
3462 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
3463 name, chip->label, hwnum, status);
3464 gpiochip_free_own_desc(desc);
3468 /* Mark GPIO as hogged so it can be identified and removed later */
3469 set_bit(FLAG_IS_HOGGED, &desc->flags);
3471 pr_info("GPIO line %d (%s) hogged as %s%s\n",
3472 desc_to_gpio(desc), name,
3473 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
3474 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
3475 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
3481 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
3482 * @chip: gpio chip to act on
3484 * This is only used by of_gpiochip_remove to free hogged gpios
3486 static void gpiochip_free_hogs(struct gpio_chip *chip)
3490 for (id = 0; id < chip->ngpio; id++) {
3491 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
3492 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
3497 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
3498 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3499 * @con_id: function within the GPIO consumer
3500 * @flags: optional GPIO initialization flags
3502 * This function acquires all the GPIOs defined under a given function.
3504 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
3505 * no GPIO has been assigned to the requested function, or another IS_ERR()
3506 * code if an error occurred while trying to acquire the GPIOs.
3508 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
3510 enum gpiod_flags flags)
3512 struct gpio_desc *desc;
3513 struct gpio_descs *descs;
3516 count = gpiod_count(dev, con_id);
3518 return ERR_PTR(count);
3520 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
3523 return ERR_PTR(-ENOMEM);
3525 for (descs->ndescs = 0; descs->ndescs < count; ) {
3526 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
3528 gpiod_put_array(descs);
3529 return ERR_CAST(desc);
3531 descs->desc[descs->ndescs] = desc;
3536 EXPORT_SYMBOL_GPL(gpiod_get_array);
3539 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
3541 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3542 * @con_id: function within the GPIO consumer
3543 * @flags: optional GPIO initialization flags
3545 * This is equivalent to gpiod_get_array(), except that when no GPIO was
3546 * assigned to the requested function it will return NULL.
3548 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
3550 enum gpiod_flags flags)
3552 struct gpio_descs *descs;
3554 descs = gpiod_get_array(dev, con_id, flags);
3555 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
3560 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
3563 * gpiod_put - dispose of a GPIO descriptor
3564 * @desc: GPIO descriptor to dispose of
3566 * No descriptor can be used after gpiod_put() has been called on it.
3568 void gpiod_put(struct gpio_desc *desc)
3572 EXPORT_SYMBOL_GPL(gpiod_put);
3575 * gpiod_put_array - dispose of multiple GPIO descriptors
3576 * @descs: struct gpio_descs containing an array of descriptors
3578 void gpiod_put_array(struct gpio_descs *descs)
3582 for (i = 0; i < descs->ndescs; i++)
3583 gpiod_put(descs->desc[i]);
3587 EXPORT_SYMBOL_GPL(gpiod_put_array);
3589 static int __init gpiolib_dev_init(void)
3593 /* Register GPIO sysfs bus */
3594 ret = bus_register(&gpio_bus_type);
3596 pr_err("gpiolib: could not register GPIO bus type\n");
3600 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
3602 pr_err("gpiolib: failed to allocate char dev region\n");
3603 bus_unregister(&gpio_bus_type);
3605 gpiolib_initialized = true;
3606 gpiochip_setup_devs();
3610 core_initcall(gpiolib_dev_init);
3612 #ifdef CONFIG_DEBUG_FS
3614 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
3617 struct gpio_chip *chip = gdev->chip;
3618 unsigned gpio = gdev->base;
3619 struct gpio_desc *gdesc = &gdev->descs[0];
3623 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
3624 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
3626 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
3632 gpiod_get_direction(gdesc);
3633 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
3634 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
3635 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
3636 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
3637 is_out ? "out" : "in ",
3639 ? (chip->get(chip, i) ? "hi" : "lo")
3641 is_irq ? "IRQ" : " ");
3642 seq_printf(s, "\n");
3646 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
3648 unsigned long flags;
3649 struct gpio_device *gdev = NULL;
3650 loff_t index = *pos;
3654 spin_lock_irqsave(&gpio_lock, flags);
3655 list_for_each_entry(gdev, &gpio_devices, list)
3657 spin_unlock_irqrestore(&gpio_lock, flags);
3660 spin_unlock_irqrestore(&gpio_lock, flags);
3665 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
3667 unsigned long flags;
3668 struct gpio_device *gdev = v;
3671 spin_lock_irqsave(&gpio_lock, flags);
3672 if (list_is_last(&gdev->list, &gpio_devices))
3675 ret = list_entry(gdev->list.next, struct gpio_device, list);
3676 spin_unlock_irqrestore(&gpio_lock, flags);
3684 static void gpiolib_seq_stop(struct seq_file *s, void *v)
3688 static int gpiolib_seq_show(struct seq_file *s, void *v)
3690 struct gpio_device *gdev = v;
3691 struct gpio_chip *chip = gdev->chip;
3692 struct device *parent;
3695 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
3696 dev_name(&gdev->dev));
3700 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
3701 dev_name(&gdev->dev),
3702 gdev->base, gdev->base + gdev->ngpio - 1);
3703 parent = chip->parent;
3705 seq_printf(s, ", parent: %s/%s",
3706 parent->bus ? parent->bus->name : "no-bus",
3709 seq_printf(s, ", %s", chip->label);
3710 if (chip->can_sleep)
3711 seq_printf(s, ", can sleep");
3712 seq_printf(s, ":\n");
3715 chip->dbg_show(s, chip);
3717 gpiolib_dbg_show(s, gdev);
3722 static const struct seq_operations gpiolib_seq_ops = {
3723 .start = gpiolib_seq_start,
3724 .next = gpiolib_seq_next,
3725 .stop = gpiolib_seq_stop,
3726 .show = gpiolib_seq_show,
3729 static int gpiolib_open(struct inode *inode, struct file *file)
3731 return seq_open(file, &gpiolib_seq_ops);
3734 static const struct file_operations gpiolib_operations = {
3735 .owner = THIS_MODULE,
3736 .open = gpiolib_open,
3738 .llseek = seq_lseek,
3739 .release = seq_release,
3742 static int __init gpiolib_debugfs_init(void)
3744 /* /sys/kernel/debug/gpio */
3745 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
3746 NULL, NULL, &gpiolib_operations);
3749 subsys_initcall(gpiolib_debugfs_init);
3751 #endif /* DEBUG_FS */