1 #include <linux/kernel.h>
2 #include <linux/module.h>
3 #include <linux/interrupt.h>
5 #include <linux/spinlock.h>
6 #include <linux/list.h>
7 #include <linux/device.h>
9 #include <linux/debugfs.h>
10 #include <linux/seq_file.h>
11 #include <linux/gpio.h>
12 #include <linux/of_gpio.h>
13 #include <linux/idr.h>
14 #include <linux/slab.h>
15 #include <linux/acpi.h>
16 #include <linux/gpio/driver.h>
17 #include <linux/gpio/machine.h>
18 #include <linux/pinctrl/consumer.h>
19 #include <linux/cdev.h>
21 #include <linux/uaccess.h>
22 #include <linux/compat.h>
23 #include <linux/anon_inodes.h>
24 #include <linux/kfifo.h>
25 #include <linux/poll.h>
26 #include <linux/timekeeping.h>
27 #include <uapi/linux/gpio.h>
31 #define CREATE_TRACE_POINTS
32 #include <trace/events/gpio.h>
34 /* Implementation infrastructure for GPIO interfaces.
36 * The GPIO programming interface allows for inlining speed-critical
37 * get/set operations for common cases, so that access to SOC-integrated
38 * GPIOs can sometimes cost only an instruction or two per bit.
42 /* When debugging, extend minimal trust to callers and platform code.
43 * Also emit diagnostic messages that may help initial bringup, when
44 * board setup or driver bugs are most common.
46 * Otherwise, minimize overhead in what may be bitbanging codepaths.
49 #define extra_checks 1
51 #define extra_checks 0
54 /* Device and char device-related information */
55 static DEFINE_IDA(gpio_ida);
56 static dev_t gpio_devt;
57 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
58 static struct bus_type gpio_bus_type = {
62 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
63 * While any GPIO is requested, its gpio_chip is not removable;
64 * each GPIO's "requested" flag serves as a lock and refcount.
66 DEFINE_SPINLOCK(gpio_lock);
68 static DEFINE_MUTEX(gpio_lookup_lock);
69 static LIST_HEAD(gpio_lookup_list);
70 LIST_HEAD(gpio_devices);
72 static void gpiochip_free_hogs(struct gpio_chip *chip);
73 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
74 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
75 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
77 static bool gpiolib_initialized;
79 static inline void desc_set_label(struct gpio_desc *d, const char *label)
85 * Convert a GPIO number to its descriptor
87 struct gpio_desc *gpio_to_desc(unsigned gpio)
89 struct gpio_device *gdev;
92 spin_lock_irqsave(&gpio_lock, flags);
94 list_for_each_entry(gdev, &gpio_devices, list) {
95 if (gdev->base <= gpio &&
96 gdev->base + gdev->ngpio > gpio) {
97 spin_unlock_irqrestore(&gpio_lock, flags);
98 return &gdev->descs[gpio - gdev->base];
102 spin_unlock_irqrestore(&gpio_lock, flags);
104 if (!gpio_is_valid(gpio))
105 WARN(1, "invalid GPIO %d\n", gpio);
109 EXPORT_SYMBOL_GPL(gpio_to_desc);
112 * Get the GPIO descriptor corresponding to the given hw number for this chip.
114 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
117 struct gpio_device *gdev = chip->gpiodev;
119 if (hwnum >= gdev->ngpio)
120 return ERR_PTR(-EINVAL);
122 return &gdev->descs[hwnum];
126 * Convert a GPIO descriptor to the integer namespace.
127 * This should disappear in the future but is needed since we still
128 * use GPIO numbers for error messages and sysfs nodes
130 int desc_to_gpio(const struct gpio_desc *desc)
132 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
134 EXPORT_SYMBOL_GPL(desc_to_gpio);
138 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
139 * @desc: descriptor to return the chip of
141 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
143 if (!desc || !desc->gdev || !desc->gdev->chip)
145 return desc->gdev->chip;
147 EXPORT_SYMBOL_GPL(gpiod_to_chip);
149 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
150 static int gpiochip_find_base(int ngpio)
152 struct gpio_device *gdev;
153 int base = ARCH_NR_GPIOS - ngpio;
155 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
156 /* found a free space? */
157 if (gdev->base + gdev->ngpio <= base)
160 /* nope, check the space right before the chip */
161 base = gdev->base - ngpio;
164 if (gpio_is_valid(base)) {
165 pr_debug("%s: found new base at %d\n", __func__, base);
168 pr_err("%s: cannot find free range\n", __func__);
174 * gpiod_get_direction - return the current direction of a GPIO
175 * @desc: GPIO to get the direction of
177 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
179 * This function may sleep if gpiod_cansleep() is true.
181 int gpiod_get_direction(struct gpio_desc *desc)
183 struct gpio_chip *chip;
185 int status = -EINVAL;
187 chip = gpiod_to_chip(desc);
188 offset = gpio_chip_hwgpio(desc);
190 if (!chip->get_direction)
193 status = chip->get_direction(chip, offset);
195 /* GPIOF_DIR_IN, or other positive */
197 clear_bit(FLAG_IS_OUT, &desc->flags);
201 set_bit(FLAG_IS_OUT, &desc->flags);
205 EXPORT_SYMBOL_GPL(gpiod_get_direction);
208 * Add a new chip to the global chips list, keeping the list of chips sorted
209 * by range(means [base, base + ngpio - 1]) order.
211 * Return -EBUSY if the new chip overlaps with some other chip's integer
214 static int gpiodev_add_to_list(struct gpio_device *gdev)
216 struct gpio_device *prev, *next;
218 if (list_empty(&gpio_devices)) {
219 /* initial entry in list */
220 list_add_tail(&gdev->list, &gpio_devices);
224 next = list_entry(gpio_devices.next, struct gpio_device, list);
225 if (gdev->base + gdev->ngpio <= next->base) {
226 /* add before first entry */
227 list_add(&gdev->list, &gpio_devices);
231 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
232 if (prev->base + prev->ngpio <= gdev->base) {
233 /* add behind last entry */
234 list_add_tail(&gdev->list, &gpio_devices);
238 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
239 /* at the end of the list */
240 if (&next->list == &gpio_devices)
243 /* add between prev and next */
244 if (prev->base + prev->ngpio <= gdev->base
245 && gdev->base + gdev->ngpio <= next->base) {
246 list_add(&gdev->list, &prev->list);
251 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
256 * Convert a GPIO name to its descriptor
258 static struct gpio_desc *gpio_name_to_desc(const char * const name)
260 struct gpio_device *gdev;
263 spin_lock_irqsave(&gpio_lock, flags);
265 list_for_each_entry(gdev, &gpio_devices, list) {
268 for (i = 0; i != gdev->ngpio; ++i) {
269 struct gpio_desc *desc = &gdev->descs[i];
271 if (!desc->name || !name)
274 if (!strcmp(desc->name, name)) {
275 spin_unlock_irqrestore(&gpio_lock, flags);
281 spin_unlock_irqrestore(&gpio_lock, flags);
287 * Takes the names from gc->names and checks if they are all unique. If they
288 * are, they are assigned to their gpio descriptors.
290 * Warning if one of the names is already used for a different GPIO.
292 static int gpiochip_set_desc_names(struct gpio_chip *gc)
294 struct gpio_device *gdev = gc->gpiodev;
300 /* First check all names if they are unique */
301 for (i = 0; i != gc->ngpio; ++i) {
302 struct gpio_desc *gpio;
304 gpio = gpio_name_to_desc(gc->names[i]);
307 "Detected name collision for GPIO name '%s'\n",
311 /* Then add all names to the GPIO descriptors */
312 for (i = 0; i != gc->ngpio; ++i)
313 gdev->descs[i].name = gc->names[i];
319 * GPIO line handle management
323 * struct linehandle_state - contains the state of a userspace handle
324 * @gdev: the GPIO device the handle pertains to
325 * @label: consumer label used to tag descriptors
326 * @descs: the GPIO descriptors held by this handle
327 * @numdescs: the number of descriptors held in the descs array
329 struct linehandle_state {
330 struct gpio_device *gdev;
332 struct gpio_desc *descs[GPIOHANDLES_MAX];
336 static long linehandle_ioctl(struct file *filep, unsigned int cmd,
339 struct linehandle_state *lh = filep->private_data;
340 void __user *ip = (void __user *)arg;
341 struct gpiohandle_data ghd;
344 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
347 /* TODO: check if descriptors are really input */
348 for (i = 0; i < lh->numdescs; i++) {
349 val = gpiod_get_value_cansleep(lh->descs[i]);
355 if (copy_to_user(ip, &ghd, sizeof(ghd)))
359 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
360 int vals[GPIOHANDLES_MAX];
362 /* TODO: check if descriptors are really output */
363 if (copy_from_user(&ghd, ip, sizeof(ghd)))
366 /* Clamp all values to [0,1] */
367 for (i = 0; i < lh->numdescs; i++)
368 vals[i] = !!ghd.values[i];
370 /* Reuse the array setting function */
371 gpiod_set_array_value_complex(false,
382 static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
385 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
389 static int linehandle_release(struct inode *inode, struct file *filep)
391 struct linehandle_state *lh = filep->private_data;
392 struct gpio_device *gdev = lh->gdev;
395 for (i = 0; i < lh->numdescs; i++)
396 gpiod_free(lh->descs[i]);
399 put_device(&gdev->dev);
403 static const struct file_operations linehandle_fileops = {
404 .release = linehandle_release,
405 .owner = THIS_MODULE,
406 .llseek = noop_llseek,
407 .unlocked_ioctl = linehandle_ioctl,
409 .compat_ioctl = linehandle_ioctl_compat,
413 static int linehandle_create(struct gpio_device *gdev, void __user *ip)
415 struct gpiohandle_request handlereq;
416 struct linehandle_state *lh;
419 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
421 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
424 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
428 get_device(&gdev->dev);
430 /* Make sure this is terminated */
431 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
432 if (strlen(handlereq.consumer_label)) {
433 lh->label = kstrdup(handlereq.consumer_label,
441 /* Request each GPIO */
442 for (i = 0; i < handlereq.lines; i++) {
443 u32 offset = handlereq.lineoffsets[i];
444 u32 lflags = handlereq.flags;
445 struct gpio_desc *desc;
447 if (offset >= gdev->ngpio) {
452 desc = &gdev->descs[offset];
453 ret = gpiod_request(desc, lh->label);
458 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
459 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
460 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
461 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
462 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
463 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
466 * Lines have to be requested explicitly for input
467 * or output, else the line will be treated "as is".
469 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
470 int val = !!handlereq.default_values[i];
472 ret = gpiod_direction_output(desc, val);
475 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
476 ret = gpiod_direction_input(desc);
480 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
483 /* Let i point at the last handle */
485 lh->numdescs = handlereq.lines;
487 fd = anon_inode_getfd("gpio-linehandle",
490 O_RDONLY | O_CLOEXEC);
497 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
502 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
509 gpiod_free(lh->descs[i]);
513 put_device(&gdev->dev);
518 * GPIO line event management
522 * struct lineevent_state - contains the state of a userspace event
523 * @gdev: the GPIO device the event pertains to
524 * @label: consumer label used to tag descriptors
525 * @desc: the GPIO descriptor held by this event
526 * @eflags: the event flags this line was requested with
527 * @irq: the interrupt that trigger in response to events on this GPIO
528 * @wait: wait queue that handles blocking reads of events
529 * @events: KFIFO for the GPIO events
530 * @read_lock: mutex lock to protect reads from colliding with adding
531 * new events to the FIFO
533 struct lineevent_state {
534 struct gpio_device *gdev;
536 struct gpio_desc *desc;
539 wait_queue_head_t wait;
540 DECLARE_KFIFO(events, struct gpioevent_data, 16);
541 struct mutex read_lock;
544 static unsigned int lineevent_poll(struct file *filep,
545 struct poll_table_struct *wait)
547 struct lineevent_state *le = filep->private_data;
548 unsigned int events = 0;
550 poll_wait(filep, &le->wait, wait);
552 if (!kfifo_is_empty(&le->events))
553 events = POLLIN | POLLRDNORM;
559 static ssize_t lineevent_read(struct file *filep,
564 struct lineevent_state *le = filep->private_data;
568 if (count < sizeof(struct gpioevent_data))
572 if (kfifo_is_empty(&le->events)) {
573 if (filep->f_flags & O_NONBLOCK)
576 ret = wait_event_interruptible(le->wait,
577 !kfifo_is_empty(&le->events));
582 if (mutex_lock_interruptible(&le->read_lock))
584 ret = kfifo_to_user(&le->events, buf, count, &copied);
585 mutex_unlock(&le->read_lock);
591 * If we couldn't read anything from the fifo (a different
592 * thread might have been faster) we either return -EAGAIN if
593 * the file descriptor is non-blocking, otherwise we go back to
594 * sleep and wait for more data to arrive.
596 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
599 } while (copied == 0);
604 static int lineevent_release(struct inode *inode, struct file *filep)
606 struct lineevent_state *le = filep->private_data;
607 struct gpio_device *gdev = le->gdev;
609 free_irq(le->irq, le);
610 gpiod_free(le->desc);
613 put_device(&gdev->dev);
617 static long lineevent_ioctl(struct file *filep, unsigned int cmd,
620 struct lineevent_state *le = filep->private_data;
621 void __user *ip = (void __user *)arg;
622 struct gpiohandle_data ghd;
625 * We can get the value for an event line but not set it,
626 * because it is input by definition.
628 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
631 memset(&ghd, 0, sizeof(ghd));
633 val = gpiod_get_value_cansleep(le->desc);
638 if (copy_to_user(ip, &ghd, sizeof(ghd)))
647 static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
650 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
654 static const struct file_operations lineevent_fileops = {
655 .release = lineevent_release,
656 .read = lineevent_read,
657 .poll = lineevent_poll,
658 .owner = THIS_MODULE,
659 .llseek = noop_llseek,
660 .unlocked_ioctl = lineevent_ioctl,
662 .compat_ioctl = lineevent_ioctl_compat,
666 static irqreturn_t lineevent_irq_thread(int irq, void *p)
668 struct lineevent_state *le = p;
669 struct gpioevent_data ge;
672 ge.timestamp = ktime_get_real_ns();
674 if (le->eflags & GPIOEVENT_REQUEST_BOTH_EDGES) {
675 int level = gpiod_get_value_cansleep(le->desc);
678 /* Emit low-to-high event */
679 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
681 /* Emit high-to-low event */
682 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
683 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
684 /* Emit low-to-high event */
685 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
686 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
687 /* Emit high-to-low event */
688 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
693 ret = kfifo_put(&le->events, ge);
695 wake_up_poll(&le->wait, POLLIN);
700 static int lineevent_create(struct gpio_device *gdev, void __user *ip)
702 struct gpioevent_request eventreq;
703 struct lineevent_state *le;
704 struct gpio_desc *desc;
712 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
715 le = kzalloc(sizeof(*le), GFP_KERNEL);
719 get_device(&gdev->dev);
721 /* Make sure this is terminated */
722 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
723 if (strlen(eventreq.consumer_label)) {
724 le->label = kstrdup(eventreq.consumer_label,
732 offset = eventreq.lineoffset;
733 lflags = eventreq.handleflags;
734 eflags = eventreq.eventflags;
736 /* This is just wrong: we don't look for events on output lines */
737 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
742 desc = &gdev->descs[offset];
743 ret = gpiod_request(desc, le->label);
749 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
750 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
751 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
752 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
753 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
754 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
756 ret = gpiod_direction_input(desc);
760 le->irq = gpiod_to_irq(desc);
766 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
767 irqflags |= IRQF_TRIGGER_RISING;
768 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
769 irqflags |= IRQF_TRIGGER_FALLING;
770 irqflags |= IRQF_ONESHOT;
771 irqflags |= IRQF_SHARED;
773 INIT_KFIFO(le->events);
774 init_waitqueue_head(&le->wait);
775 mutex_init(&le->read_lock);
777 /* Request a thread to read the events */
778 ret = request_threaded_irq(le->irq,
780 lineevent_irq_thread,
787 fd = anon_inode_getfd("gpio-event",
790 O_RDONLY | O_CLOEXEC);
797 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
805 free_irq(le->irq, le);
807 gpiod_free(le->desc);
812 put_device(&gdev->dev);
817 * gpio_ioctl() - ioctl handler for the GPIO chardev
819 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
821 struct gpio_device *gdev = filp->private_data;
822 struct gpio_chip *chip = gdev->chip;
823 void __user *ip = (void __user *)arg;
825 /* We fail any subsequent ioctl():s when the chip is gone */
829 /* Fill in the struct and pass to userspace */
830 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
831 struct gpiochip_info chipinfo;
833 memset(&chipinfo, 0, sizeof(chipinfo));
835 strncpy(chipinfo.name, dev_name(&gdev->dev),
836 sizeof(chipinfo.name));
837 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
838 strncpy(chipinfo.label, gdev->label,
839 sizeof(chipinfo.label));
840 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
841 chipinfo.lines = gdev->ngpio;
842 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
845 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
846 struct gpioline_info lineinfo;
847 struct gpio_desc *desc;
849 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
851 if (lineinfo.line_offset >= gdev->ngpio)
854 desc = &gdev->descs[lineinfo.line_offset];
856 strncpy(lineinfo.name, desc->name,
857 sizeof(lineinfo.name));
858 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
860 lineinfo.name[0] = '\0';
863 strncpy(lineinfo.consumer, desc->label,
864 sizeof(lineinfo.consumer));
865 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
867 lineinfo.consumer[0] = '\0';
871 * Userspace only need to know that the kernel is using
872 * this GPIO so it can't use it.
875 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
876 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
877 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
878 test_bit(FLAG_EXPORT, &desc->flags) ||
879 test_bit(FLAG_SYSFS, &desc->flags))
880 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
881 if (test_bit(FLAG_IS_OUT, &desc->flags))
882 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
883 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
884 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
885 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
886 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
887 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
888 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
890 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
893 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
894 return linehandle_create(gdev, ip);
895 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
896 return lineevent_create(gdev, ip);
902 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
905 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
910 * gpio_chrdev_open() - open the chardev for ioctl operations
911 * @inode: inode for this chardev
912 * @filp: file struct for storing private data
913 * Returns 0 on success
915 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
917 struct gpio_device *gdev = container_of(inode->i_cdev,
918 struct gpio_device, chrdev);
920 /* Fail on open if the backing gpiochip is gone */
921 if (!gdev || !gdev->chip)
923 get_device(&gdev->dev);
924 filp->private_data = gdev;
929 * gpio_chrdev_release() - close chardev after ioctl operations
930 * @inode: inode for this chardev
931 * @filp: file struct for storing private data
932 * Returns 0 on success
934 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
936 struct gpio_device *gdev = container_of(inode->i_cdev,
937 struct gpio_device, chrdev);
941 put_device(&gdev->dev);
946 static const struct file_operations gpio_fileops = {
947 .release = gpio_chrdev_release,
948 .open = gpio_chrdev_open,
949 .owner = THIS_MODULE,
950 .llseek = noop_llseek,
951 .unlocked_ioctl = gpio_ioctl,
953 .compat_ioctl = gpio_ioctl_compat,
957 static void gpiodevice_release(struct device *dev)
959 struct gpio_device *gdev = dev_get_drvdata(dev);
961 list_del(&gdev->list);
962 ida_simple_remove(&gpio_ida, gdev->id);
968 static int gpiochip_setup_dev(struct gpio_device *gdev)
972 cdev_init(&gdev->chrdev, &gpio_fileops);
973 gdev->chrdev.owner = THIS_MODULE;
974 gdev->chrdev.kobj.parent = &gdev->dev.kobj;
975 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
976 status = cdev_add(&gdev->chrdev, gdev->dev.devt, 1);
978 chip_warn(gdev->chip, "failed to add char device %d:%d\n",
979 MAJOR(gpio_devt), gdev->id);
981 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
982 MAJOR(gpio_devt), gdev->id);
983 status = device_add(&gdev->dev);
985 goto err_remove_chardev;
987 status = gpiochip_sysfs_register(gdev);
989 goto err_remove_device;
991 /* From this point, the .release() function cleans up gpio_device */
992 gdev->dev.release = gpiodevice_release;
993 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
994 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
995 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1000 device_del(&gdev->dev);
1002 cdev_del(&gdev->chrdev);
1006 static void gpiochip_setup_devs(void)
1008 struct gpio_device *gdev;
1011 list_for_each_entry(gdev, &gpio_devices, list) {
1012 err = gpiochip_setup_dev(gdev);
1014 pr_err("%s: Failed to initialize gpio device (%d)\n",
1015 dev_name(&gdev->dev), err);
1020 * gpiochip_add_data() - register a gpio_chip
1021 * @chip: the chip to register, with chip->base initialized
1022 * Context: potentially before irqs will work
1024 * Returns a negative errno if the chip can't be registered, such as
1025 * because the chip->base is invalid or already associated with a
1026 * different chip. Otherwise it returns zero as a success code.
1028 * When gpiochip_add_data() is called very early during boot, so that GPIOs
1029 * can be freely used, the chip->parent device must be registered before
1030 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
1031 * for GPIOs will fail rudely.
1033 * gpiochip_add_data() must only be called after gpiolib initialization,
1034 * ie after core_initcall().
1036 * If chip->base is negative, this requests dynamic assignment of
1037 * a range of valid GPIOs.
1039 int gpiochip_add_data(struct gpio_chip *chip, void *data)
1041 unsigned long flags;
1044 int base = chip->base;
1045 struct gpio_device *gdev;
1048 * First: allocate and populate the internal stat container, and
1049 * set up the struct device.
1051 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1054 gdev->dev.bus = &gpio_bus_type;
1056 chip->gpiodev = gdev;
1058 gdev->dev.parent = chip->parent;
1059 gdev->dev.of_node = chip->parent->of_node;
1062 #ifdef CONFIG_OF_GPIO
1063 /* If the gpiochip has an assigned OF node this takes precedence */
1065 gdev->dev.of_node = chip->of_node;
1068 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1073 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1074 device_initialize(&gdev->dev);
1075 dev_set_drvdata(&gdev->dev, gdev);
1076 if (chip->parent && chip->parent->driver)
1077 gdev->owner = chip->parent->driver->owner;
1078 else if (chip->owner)
1079 /* TODO: remove chip->owner */
1080 gdev->owner = chip->owner;
1082 gdev->owner = THIS_MODULE;
1084 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1090 if (chip->ngpio == 0) {
1091 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1093 goto err_free_descs;
1097 gdev->label = kstrdup(chip->label, GFP_KERNEL);
1099 gdev->label = kstrdup("unknown", GFP_KERNEL);
1102 goto err_free_descs;
1105 gdev->ngpio = chip->ngpio;
1108 spin_lock_irqsave(&gpio_lock, flags);
1111 * TODO: this allocates a Linux GPIO number base in the global
1112 * GPIO numberspace for this chip. In the long run we want to
1113 * get *rid* of this numberspace and use only descriptors, but
1114 * it may be a pipe dream. It will not happen before we get rid
1115 * of the sysfs interface anyways.
1118 base = gpiochip_find_base(chip->ngpio);
1121 spin_unlock_irqrestore(&gpio_lock, flags);
1122 goto err_free_label;
1125 * TODO: it should not be necessary to reflect the assigned
1126 * base outside of the GPIO subsystem. Go over drivers and
1127 * see if anyone makes use of this, else drop this and assign
1134 status = gpiodev_add_to_list(gdev);
1136 spin_unlock_irqrestore(&gpio_lock, flags);
1137 goto err_free_label;
1140 spin_unlock_irqrestore(&gpio_lock, flags);
1142 for (i = 0; i < chip->ngpio; i++) {
1143 struct gpio_desc *desc = &gdev->descs[i];
1147 * REVISIT: most hardware initializes GPIOs as inputs
1148 * (often with pullups enabled) so power usage is
1149 * minimized. Linux code should set the gpio direction
1150 * first thing; but until it does, and in case
1151 * chip->get_direction is not set, we may expose the
1152 * wrong direction in sysfs.
1155 if (chip->get_direction) {
1157 * If we have .get_direction, set up the initial
1158 * direction flag from the hardware.
1160 int dir = chip->get_direction(chip, i);
1163 set_bit(FLAG_IS_OUT, &desc->flags);
1164 } else if (!chip->direction_input) {
1166 * If the chip lacks the .direction_input callback
1167 * we logically assume all lines are outputs.
1169 set_bit(FLAG_IS_OUT, &desc->flags);
1173 #ifdef CONFIG_PINCTRL
1174 INIT_LIST_HEAD(&gdev->pin_ranges);
1177 status = gpiochip_set_desc_names(chip);
1179 goto err_remove_from_list;
1181 status = gpiochip_irqchip_init_valid_mask(chip);
1183 goto err_remove_from_list;
1185 status = of_gpiochip_add(chip);
1187 goto err_remove_chip;
1189 acpi_gpiochip_add(chip);
1192 * By first adding the chardev, and then adding the device,
1193 * we get a device node entry in sysfs under
1194 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1195 * coldplug of device nodes and other udev business.
1196 * We can do this only if gpiolib has been initialized.
1197 * Otherwise, defer until later.
1199 if (gpiolib_initialized) {
1200 status = gpiochip_setup_dev(gdev);
1202 goto err_remove_chip;
1207 acpi_gpiochip_remove(chip);
1208 gpiochip_free_hogs(chip);
1209 of_gpiochip_remove(chip);
1210 gpiochip_irqchip_free_valid_mask(chip);
1211 err_remove_from_list:
1212 spin_lock_irqsave(&gpio_lock, flags);
1213 list_del(&gdev->list);
1214 spin_unlock_irqrestore(&gpio_lock, flags);
1220 ida_simple_remove(&gpio_ida, gdev->id);
1221 /* failures here can mean systems won't boot... */
1222 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
1223 gdev->base, gdev->base + gdev->ngpio - 1,
1224 chip->label ? : "generic");
1228 EXPORT_SYMBOL_GPL(gpiochip_add_data);
1231 * gpiochip_get_data() - get per-subdriver data for the chip
1233 void *gpiochip_get_data(struct gpio_chip *chip)
1235 return chip->gpiodev->data;
1237 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1240 * gpiochip_remove() - unregister a gpio_chip
1241 * @chip: the chip to unregister
1243 * A gpio_chip with any GPIOs still requested may not be removed.
1245 void gpiochip_remove(struct gpio_chip *chip)
1247 struct gpio_device *gdev = chip->gpiodev;
1248 struct gpio_desc *desc;
1249 unsigned long flags;
1251 bool requested = false;
1253 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1254 gpiochip_sysfs_unregister(gdev);
1255 /* Numb the device, cancelling all outstanding operations */
1257 gpiochip_irqchip_remove(chip);
1258 acpi_gpiochip_remove(chip);
1259 gpiochip_remove_pin_ranges(chip);
1260 gpiochip_free_hogs(chip);
1261 of_gpiochip_remove(chip);
1263 * We accept no more calls into the driver from this point, so
1264 * NULL the driver data pointer
1268 spin_lock_irqsave(&gpio_lock, flags);
1269 for (i = 0; i < gdev->ngpio; i++) {
1270 desc = &gdev->descs[i];
1271 if (test_bit(FLAG_REQUESTED, &desc->flags))
1274 spin_unlock_irqrestore(&gpio_lock, flags);
1277 dev_crit(&gdev->dev,
1278 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1281 * The gpiochip side puts its use of the device to rest here:
1282 * if there are no userspace clients, the chardev and device will
1283 * be removed, else it will be dangling until the last user is
1286 cdev_del(&gdev->chrdev);
1287 device_del(&gdev->dev);
1288 put_device(&gdev->dev);
1290 EXPORT_SYMBOL_GPL(gpiochip_remove);
1292 static void devm_gpio_chip_release(struct device *dev, void *res)
1294 struct gpio_chip *chip = *(struct gpio_chip **)res;
1296 gpiochip_remove(chip);
1299 static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
1302 struct gpio_chip **r = res;
1313 * devm_gpiochip_add_data() - Resource manager piochip_add_data()
1314 * @dev: the device pointer on which irq_chip belongs to.
1315 * @chip: the chip to register, with chip->base initialized
1316 * Context: potentially before irqs will work
1318 * Returns a negative errno if the chip can't be registered, such as
1319 * because the chip->base is invalid or already associated with a
1320 * different chip. Otherwise it returns zero as a success code.
1322 * The gpio chip automatically be released when the device is unbound.
1324 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1327 struct gpio_chip **ptr;
1330 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1335 ret = gpiochip_add_data(chip, data);
1342 devres_add(dev, ptr);
1346 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1349 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1350 * @dev: device for which which resource was allocated
1351 * @chip: the chip to remove
1353 * A gpio_chip with any GPIOs still requested may not be removed.
1355 void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
1359 ret = devres_release(dev, devm_gpio_chip_release,
1360 devm_gpio_chip_match, chip);
1364 EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
1367 * gpiochip_find() - iterator for locating a specific gpio_chip
1368 * @data: data to pass to match function
1369 * @callback: Callback function to check gpio_chip
1371 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1372 * determined by a user supplied @match callback. The callback should return
1373 * 0 if the device doesn't match and non-zero if it does. If the callback is
1374 * non-zero, this function will return to the caller and not iterate over any
1377 struct gpio_chip *gpiochip_find(void *data,
1378 int (*match)(struct gpio_chip *chip,
1381 struct gpio_device *gdev;
1382 struct gpio_chip *chip = NULL;
1383 unsigned long flags;
1385 spin_lock_irqsave(&gpio_lock, flags);
1386 list_for_each_entry(gdev, &gpio_devices, list)
1387 if (gdev->chip && match(gdev->chip, data)) {
1392 spin_unlock_irqrestore(&gpio_lock, flags);
1396 EXPORT_SYMBOL_GPL(gpiochip_find);
1398 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1400 const char *name = data;
1402 return !strcmp(chip->label, name);
1405 static struct gpio_chip *find_chip_by_name(const char *name)
1407 return gpiochip_find((void *)name, gpiochip_match_name);
1410 #ifdef CONFIG_GPIOLIB_IRQCHIP
1413 * The following is irqchip helper code for gpiochips.
1416 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1420 if (!gpiochip->irq_need_valid_mask)
1423 gpiochip->irq_valid_mask = kcalloc(BITS_TO_LONGS(gpiochip->ngpio),
1424 sizeof(long), GFP_KERNEL);
1425 if (!gpiochip->irq_valid_mask)
1428 /* Assume by default all GPIOs are valid */
1429 for (i = 0; i < gpiochip->ngpio; i++)
1430 set_bit(i, gpiochip->irq_valid_mask);
1435 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1437 kfree(gpiochip->irq_valid_mask);
1438 gpiochip->irq_valid_mask = NULL;
1441 static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1442 unsigned int offset)
1444 /* No mask means all valid */
1445 if (likely(!gpiochip->irq_valid_mask))
1447 return test_bit(offset, gpiochip->irq_valid_mask);
1451 * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
1452 * @gpiochip: the gpiochip to set the irqchip chain to
1453 * @irqchip: the irqchip to chain to the gpiochip
1454 * @parent_irq: the irq number corresponding to the parent IRQ for this
1456 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1457 * coming out of the gpiochip. If the interrupt is nested rather than
1458 * cascaded, pass NULL in this handler argument
1460 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1461 struct irq_chip *irqchip,
1463 irq_flow_handler_t parent_handler)
1465 unsigned int offset;
1467 if (!gpiochip->irqdomain) {
1468 chip_err(gpiochip, "called %s before setting up irqchip\n",
1473 if (parent_handler) {
1474 if (gpiochip->can_sleep) {
1476 "you cannot have chained interrupts on a "
1477 "chip that may sleep\n");
1481 * The parent irqchip is already using the chip_data for this
1482 * irqchip, so our callbacks simply use the handler_data.
1484 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1487 gpiochip->irq_parent = parent_irq;
1490 /* Set the parent IRQ for all affected IRQs */
1491 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1492 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1494 irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
1498 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1501 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1502 * @d: the irqdomain used by this irqchip
1503 * @irq: the global irq number used by this GPIO irqchip irq
1504 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1506 * This function will set up the mapping for a certain IRQ line on a
1507 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1508 * stored inside the gpiochip.
1510 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1511 irq_hw_number_t hwirq)
1513 struct gpio_chip *chip = d->host_data;
1515 irq_set_chip_data(irq, chip);
1517 * This lock class tells lockdep that GPIO irqs are in a different
1518 * category than their parents, so it won't report false recursion.
1520 irq_set_lockdep_class(irq, chip->lock_key);
1521 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
1522 /* Chips that can sleep need nested thread handlers */
1523 if (chip->can_sleep && !chip->irq_not_threaded)
1524 irq_set_nested_thread(irq, 1);
1525 irq_set_noprobe(irq);
1528 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1529 * is passed as default type.
1531 if (chip->irq_default_type != IRQ_TYPE_NONE)
1532 irq_set_irq_type(irq, chip->irq_default_type);
1537 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1539 struct gpio_chip *chip = d->host_data;
1541 if (chip->can_sleep)
1542 irq_set_nested_thread(irq, 0);
1543 irq_set_chip_and_handler(irq, NULL, NULL);
1544 irq_set_chip_data(irq, NULL);
1547 static const struct irq_domain_ops gpiochip_domain_ops = {
1548 .map = gpiochip_irq_map,
1549 .unmap = gpiochip_irq_unmap,
1550 /* Virtually all GPIO irqchips are twocell:ed */
1551 .xlate = irq_domain_xlate_twocell,
1554 static int gpiochip_irq_reqres(struct irq_data *d)
1556 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1558 if (!try_module_get(chip->gpiodev->owner))
1561 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
1563 "unable to lock HW IRQ %lu for IRQ\n",
1565 module_put(chip->gpiodev->owner);
1571 static void gpiochip_irq_relres(struct irq_data *d)
1573 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1575 gpiochip_unlock_as_irq(chip, d->hwirq);
1576 module_put(chip->gpiodev->owner);
1579 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1581 return irq_find_mapping(chip->irqdomain, offset);
1585 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1586 * @gpiochip: the gpiochip to remove the irqchip from
1588 * This is called only from gpiochip_remove()
1590 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1592 unsigned int offset;
1594 acpi_gpiochip_free_interrupts(gpiochip);
1596 if (gpiochip->irq_parent) {
1597 irq_set_chained_handler(gpiochip->irq_parent, NULL);
1598 irq_set_handler_data(gpiochip->irq_parent, NULL);
1601 /* Remove all IRQ mappings and delete the domain */
1602 if (gpiochip->irqdomain) {
1603 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1604 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1606 irq_dispose_mapping(
1607 irq_find_mapping(gpiochip->irqdomain, offset));
1609 irq_domain_remove(gpiochip->irqdomain);
1612 if (gpiochip->irqchip) {
1613 gpiochip->irqchip->irq_request_resources = NULL;
1614 gpiochip->irqchip->irq_release_resources = NULL;
1615 gpiochip->irqchip = NULL;
1618 gpiochip_irqchip_free_valid_mask(gpiochip);
1622 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
1623 * @gpiochip: the gpiochip to add the irqchip to
1624 * @irqchip: the irqchip to add to the gpiochip
1625 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1626 * allocate gpiochip irqs from
1627 * @handler: the irq handler to use (often a predefined irq core function)
1628 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1629 * to have the core avoid setting up any default type in the hardware.
1630 * @lock_key: lockdep class
1632 * This function closely associates a certain irqchip with a certain
1633 * gpiochip, providing an irq domain to translate the local IRQs to
1634 * global irqs in the gpiolib core, and making sure that the gpiochip
1635 * is passed as chip data to all related functions. Driver callbacks
1636 * need to use gpiochip_get_data() to get their local state containers back
1637 * from the gpiochip passed as chip data. An irqdomain will be stored
1638 * in the gpiochip that shall be used by the driver to handle IRQ number
1639 * translation. The gpiochip will need to be initialized and registered
1640 * before calling this function.
1642 * This function will handle two cell:ed simple IRQs and assumes all
1643 * the pins on the gpiochip can generate a unique IRQ. Everything else
1644 * need to be open coded.
1646 int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
1647 struct irq_chip *irqchip,
1648 unsigned int first_irq,
1649 irq_flow_handler_t handler,
1651 struct lock_class_key *lock_key)
1653 struct device_node *of_node;
1654 bool irq_base_set = false;
1655 unsigned int offset;
1656 unsigned irq_base = 0;
1658 if (!gpiochip || !irqchip)
1661 if (!gpiochip->parent) {
1662 pr_err("missing gpiochip .dev parent pointer\n");
1665 of_node = gpiochip->parent->of_node;
1666 #ifdef CONFIG_OF_GPIO
1668 * If the gpiochip has an assigned OF node this takes precedence
1669 * FIXME: get rid of this and use gpiochip->parent->of_node
1672 if (gpiochip->of_node)
1673 of_node = gpiochip->of_node;
1676 * Specifying a default trigger is a terrible idea if DT or ACPI is
1677 * used to configure the interrupts, as you may end-up with
1678 * conflicting triggers. Tell the user, and reset to NONE.
1680 if (WARN(of_node && type != IRQ_TYPE_NONE,
1681 "%s: Ignoring %d default trigger\n", of_node->full_name, type))
1682 type = IRQ_TYPE_NONE;
1683 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1684 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1685 "Ignoring %d default trigger\n", type);
1686 type = IRQ_TYPE_NONE;
1689 gpiochip->irqchip = irqchip;
1690 gpiochip->irq_handler = handler;
1691 gpiochip->irq_default_type = type;
1692 gpiochip->to_irq = gpiochip_to_irq;
1693 gpiochip->lock_key = lock_key;
1694 gpiochip->irqdomain = irq_domain_add_simple(of_node,
1695 gpiochip->ngpio, first_irq,
1696 &gpiochip_domain_ops, gpiochip);
1697 if (!gpiochip->irqdomain) {
1698 gpiochip->irqchip = NULL;
1703 * It is possible for a driver to override this, but only if the
1704 * alternative functions are both implemented.
1706 if (!irqchip->irq_request_resources &&
1707 !irqchip->irq_release_resources) {
1708 irqchip->irq_request_resources = gpiochip_irq_reqres;
1709 irqchip->irq_release_resources = gpiochip_irq_relres;
1713 * Prepare the mapping since the irqchip shall be orthogonal to
1714 * any gpiochip calls. If the first_irq was zero, this is
1715 * necessary to allocate descriptors for all IRQs.
1717 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1718 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1720 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
1721 if (!irq_base_set) {
1723 * Store the base into the gpiochip to be used when
1724 * unmapping the irqs.
1726 gpiochip->irq_base = irq_base;
1727 irq_base_set = true;
1731 acpi_gpiochip_request_interrupts(gpiochip);
1735 EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add);
1737 #else /* CONFIG_GPIOLIB_IRQCHIP */
1739 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
1740 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1744 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1747 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1750 * gpiochip_generic_request() - request the gpio function for a pin
1751 * @chip: the gpiochip owning the GPIO
1752 * @offset: the offset of the GPIO to request for GPIO function
1754 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
1756 return pinctrl_request_gpio(chip->gpiodev->base + offset);
1758 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1761 * gpiochip_generic_free() - free the gpio function from a pin
1762 * @chip: the gpiochip to request the gpio function for
1763 * @offset: the offset of the GPIO to free from GPIO function
1765 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
1767 pinctrl_free_gpio(chip->gpiodev->base + offset);
1769 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1771 #ifdef CONFIG_PINCTRL
1774 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1775 * @chip: the gpiochip to add the range for
1776 * @pctldev: the pin controller to map to
1777 * @gpio_offset: the start offset in the current gpio_chip number space
1778 * @pin_group: name of the pin group inside the pin controller
1780 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
1781 struct pinctrl_dev *pctldev,
1782 unsigned int gpio_offset, const char *pin_group)
1784 struct gpio_pin_range *pin_range;
1785 struct gpio_device *gdev = chip->gpiodev;
1788 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1790 chip_err(chip, "failed to allocate pin ranges\n");
1794 /* Use local offset as range ID */
1795 pin_range->range.id = gpio_offset;
1796 pin_range->range.gc = chip;
1797 pin_range->range.name = chip->label;
1798 pin_range->range.base = gdev->base + gpio_offset;
1799 pin_range->pctldev = pctldev;
1801 ret = pinctrl_get_group_pins(pctldev, pin_group,
1802 &pin_range->range.pins,
1803 &pin_range->range.npins);
1809 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1811 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1812 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1813 pinctrl_dev_get_devname(pctldev), pin_group);
1815 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1819 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1822 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1823 * @chip: the gpiochip to add the range for
1824 * @pinctrl_name: the dev_name() of the pin controller to map to
1825 * @gpio_offset: the start offset in the current gpio_chip number space
1826 * @pin_offset: the start offset in the pin controller number space
1827 * @npins: the number of pins from the offset of each pin space (GPIO and
1828 * pin controller) to accumulate in this range
1830 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
1831 unsigned int gpio_offset, unsigned int pin_offset,
1834 struct gpio_pin_range *pin_range;
1835 struct gpio_device *gdev = chip->gpiodev;
1838 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1840 chip_err(chip, "failed to allocate pin ranges\n");
1844 /* Use local offset as range ID */
1845 pin_range->range.id = gpio_offset;
1846 pin_range->range.gc = chip;
1847 pin_range->range.name = chip->label;
1848 pin_range->range.base = gdev->base + gpio_offset;
1849 pin_range->range.pin_base = pin_offset;
1850 pin_range->range.npins = npins;
1851 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1853 if (IS_ERR(pin_range->pctldev)) {
1854 ret = PTR_ERR(pin_range->pctldev);
1855 chip_err(chip, "could not create pin range\n");
1859 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1860 gpio_offset, gpio_offset + npins - 1,
1862 pin_offset, pin_offset + npins - 1);
1864 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1868 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1871 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1872 * @chip: the chip to remove all the mappings for
1874 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
1876 struct gpio_pin_range *pin_range, *tmp;
1877 struct gpio_device *gdev = chip->gpiodev;
1879 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1880 list_del(&pin_range->node);
1881 pinctrl_remove_gpio_range(pin_range->pctldev,
1886 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1888 #endif /* CONFIG_PINCTRL */
1890 /* These "optional" allocation calls help prevent drivers from stomping
1891 * on each other, and help provide better diagnostics in debugfs.
1892 * They're called even less than the "set direction" calls.
1894 static int __gpiod_request(struct gpio_desc *desc, const char *label)
1896 struct gpio_chip *chip = desc->gdev->chip;
1898 unsigned long flags;
1900 spin_lock_irqsave(&gpio_lock, flags);
1902 /* NOTE: gpio_request() can be called in early boot,
1903 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1906 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1907 desc_set_label(desc, label ? : "?");
1914 if (chip->request) {
1915 /* chip->request may sleep */
1916 spin_unlock_irqrestore(&gpio_lock, flags);
1917 status = chip->request(chip, gpio_chip_hwgpio(desc));
1918 spin_lock_irqsave(&gpio_lock, flags);
1921 desc_set_label(desc, NULL);
1922 clear_bit(FLAG_REQUESTED, &desc->flags);
1926 if (chip->get_direction) {
1927 /* chip->get_direction may sleep */
1928 spin_unlock_irqrestore(&gpio_lock, flags);
1929 gpiod_get_direction(desc);
1930 spin_lock_irqsave(&gpio_lock, flags);
1933 spin_unlock_irqrestore(&gpio_lock, flags);
1938 * This descriptor validation needs to be inserted verbatim into each
1939 * function taking a descriptor, so we need to use a preprocessor
1940 * macro to avoid endless duplication. If the desc is NULL it is an
1941 * optional GPIO and calls should just bail out.
1943 #define VALIDATE_DESC(desc) do { \
1946 if (IS_ERR(desc)) { \
1947 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
1948 return PTR_ERR(desc); \
1950 if (!desc->gdev) { \
1951 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
1954 if ( !desc->gdev->chip ) { \
1955 dev_warn(&desc->gdev->dev, \
1956 "%s: backing chip is gone\n", __func__); \
1960 #define VALIDATE_DESC_VOID(desc) do { \
1963 if (IS_ERR(desc)) { \
1964 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
1967 if (!desc->gdev) { \
1968 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
1971 if (!desc->gdev->chip) { \
1972 dev_warn(&desc->gdev->dev, \
1973 "%s: backing chip is gone\n", __func__); \
1978 int gpiod_request(struct gpio_desc *desc, const char *label)
1980 int status = -EPROBE_DEFER;
1981 struct gpio_device *gdev;
1983 VALIDATE_DESC(desc);
1986 if (try_module_get(gdev->owner)) {
1987 status = __gpiod_request(desc, label);
1989 module_put(gdev->owner);
1991 get_device(&gdev->dev);
1995 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2000 static bool __gpiod_free(struct gpio_desc *desc)
2003 unsigned long flags;
2004 struct gpio_chip *chip;
2008 gpiod_unexport(desc);
2010 spin_lock_irqsave(&gpio_lock, flags);
2012 chip = desc->gdev->chip;
2013 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2015 spin_unlock_irqrestore(&gpio_lock, flags);
2016 might_sleep_if(chip->can_sleep);
2017 chip->free(chip, gpio_chip_hwgpio(desc));
2018 spin_lock_irqsave(&gpio_lock, flags);
2020 desc_set_label(desc, NULL);
2021 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2022 clear_bit(FLAG_REQUESTED, &desc->flags);
2023 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2024 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2025 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2029 spin_unlock_irqrestore(&gpio_lock, flags);
2033 void gpiod_free(struct gpio_desc *desc)
2035 if (desc && desc->gdev && __gpiod_free(desc)) {
2036 module_put(desc->gdev->owner);
2037 put_device(&desc->gdev->dev);
2039 WARN_ON(extra_checks);
2044 * gpiochip_is_requested - return string iff signal was requested
2045 * @chip: controller managing the signal
2046 * @offset: of signal within controller's 0..(ngpio - 1) range
2048 * Returns NULL if the GPIO is not currently requested, else a string.
2049 * The string returned is the label passed to gpio_request(); if none has been
2050 * passed it is a meaningless, non-NULL constant.
2052 * This function is for use by GPIO controller drivers. The label can
2053 * help with diagnostics, and knowing that the signal is used as a GPIO
2054 * can help avoid accidentally multiplexing it to another controller.
2056 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2058 struct gpio_desc *desc;
2060 if (offset >= chip->ngpio)
2063 desc = &chip->gpiodev->descs[offset];
2065 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2069 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2072 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2073 * @desc: GPIO descriptor to request
2074 * @label: label for the GPIO
2076 * Function allows GPIO chip drivers to request and use their own GPIO
2077 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2078 * function will not increase reference count of the GPIO chip module. This
2079 * allows the GPIO chip module to be unloaded as needed (we assume that the
2080 * GPIO chip driver handles freeing the GPIOs it has requested).
2082 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2085 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2089 chip_err(chip, "failed to get GPIO descriptor\n");
2093 err = __gpiod_request(desc, label);
2095 return ERR_PTR(err);
2099 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2102 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2103 * @desc: GPIO descriptor to free
2105 * Function frees the given GPIO requested previously with
2106 * gpiochip_request_own_desc().
2108 void gpiochip_free_own_desc(struct gpio_desc *desc)
2113 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2116 * Drivers MUST set GPIO direction before making get/set calls. In
2117 * some cases this is done in early boot, before IRQs are enabled.
2119 * As a rule these aren't called more than once (except for drivers
2120 * using the open-drain emulation idiom) so these are natural places
2121 * to accumulate extra debugging checks. Note that we can't (yet)
2122 * rely on gpio_request() having been called beforehand.
2126 * gpiod_direction_input - set the GPIO direction to input
2127 * @desc: GPIO to set to input
2129 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2130 * be called safely on it.
2132 * Return 0 in case of success, else an error code.
2134 int gpiod_direction_input(struct gpio_desc *desc)
2136 struct gpio_chip *chip;
2137 int status = -EINVAL;
2139 VALIDATE_DESC(desc);
2140 chip = desc->gdev->chip;
2142 if (!chip->get || !chip->direction_input) {
2144 "%s: missing get() or direction_input() operations\n",
2149 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2151 clear_bit(FLAG_IS_OUT, &desc->flags);
2153 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2157 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2159 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2161 struct gpio_chip *gc = desc->gdev->chip;
2164 /* GPIOs used for IRQs shall not be set as output */
2165 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
2167 "%s: tried to set a GPIO tied to an IRQ as output\n",
2172 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2173 /* First see if we can enable open drain in hardware */
2174 if (gc->set_single_ended) {
2175 ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
2176 LINE_MODE_OPEN_DRAIN);
2178 goto set_output_value;
2180 /* Emulate open drain by not actively driving the line high */
2182 return gpiod_direction_input(desc);
2184 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2185 if (gc->set_single_ended) {
2186 ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
2187 LINE_MODE_OPEN_SOURCE);
2189 goto set_output_value;
2191 /* Emulate open source by not actively driving the line low */
2193 return gpiod_direction_input(desc);
2195 /* Make sure to disable open drain/source hardware, if any */
2196 if (gc->set_single_ended)
2197 gc->set_single_ended(gc,
2198 gpio_chip_hwgpio(desc),
2199 LINE_MODE_PUSH_PULL);
2203 if (!gc->set || !gc->direction_output) {
2205 "%s: missing set() or direction_output() operations\n",
2210 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), value);
2212 set_bit(FLAG_IS_OUT, &desc->flags);
2213 trace_gpio_value(desc_to_gpio(desc), 0, value);
2214 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2219 * gpiod_direction_output_raw - set the GPIO direction to output
2220 * @desc: GPIO to set to output
2221 * @value: initial output value of the GPIO
2223 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2224 * be called safely on it. The initial value of the output must be specified
2225 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2227 * Return 0 in case of success, else an error code.
2229 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2231 VALIDATE_DESC(desc);
2232 return _gpiod_direction_output_raw(desc, value);
2234 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2237 * gpiod_direction_output - set the GPIO direction to output
2238 * @desc: GPIO to set to output
2239 * @value: initial output value of the GPIO
2241 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2242 * be called safely on it. The initial value of the output must be specified
2243 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2246 * Return 0 in case of success, else an error code.
2248 int gpiod_direction_output(struct gpio_desc *desc, int value)
2250 VALIDATE_DESC(desc);
2251 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2253 return _gpiod_direction_output_raw(desc, value);
2255 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2258 * gpiod_set_debounce - sets @debounce time for a @gpio
2259 * @gpio: the gpio to set debounce time
2260 * @debounce: debounce time is microseconds
2262 * returns -ENOTSUPP if the controller does not support setting
2265 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2267 struct gpio_chip *chip;
2269 VALIDATE_DESC(desc);
2270 chip = desc->gdev->chip;
2271 if (!chip->set || !chip->set_debounce) {
2273 "%s: missing set() or set_debounce() operations\n",
2278 return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);
2280 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2283 * gpiod_is_active_low - test whether a GPIO is active-low or not
2284 * @desc: the gpio descriptor to test
2286 * Returns 1 if the GPIO is active-low, 0 otherwise.
2288 int gpiod_is_active_low(const struct gpio_desc *desc)
2290 VALIDATE_DESC(desc);
2291 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2293 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2295 /* I/O calls are only valid after configuration completed; the relevant
2296 * "is this a valid GPIO" error checks should already have been done.
2298 * "Get" operations are often inlinable as reading a pin value register,
2299 * and masking the relevant bit in that register.
2301 * When "set" operations are inlinable, they involve writing that mask to
2302 * one register to set a low value, or a different register to set it high.
2303 * Otherwise locking is needed, so there may be little value to inlining.
2305 *------------------------------------------------------------------------
2307 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2308 * have requested the GPIO. That can include implicit requesting by
2309 * a direction setting call. Marking a gpio as requested locks its chip
2310 * in memory, guaranteeing that these table lookups need no more locking
2311 * and that gpiochip_remove() will fail.
2313 * REVISIT when debugging, consider adding some instrumentation to ensure
2314 * that the GPIO was actually requested.
2317 static int _gpiod_get_raw_value(const struct gpio_desc *desc)
2319 struct gpio_chip *chip;
2323 chip = desc->gdev->chip;
2324 offset = gpio_chip_hwgpio(desc);
2325 value = chip->get ? chip->get(chip, offset) : -EIO;
2326 value = value < 0 ? value : !!value;
2327 trace_gpio_value(desc_to_gpio(desc), 1, value);
2332 * gpiod_get_raw_value() - return a gpio's raw value
2333 * @desc: gpio whose value will be returned
2335 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2336 * its ACTIVE_LOW status, or negative errno on failure.
2338 * This function should be called from contexts where we cannot sleep, and will
2339 * complain if the GPIO chip functions potentially sleep.
2341 int gpiod_get_raw_value(const struct gpio_desc *desc)
2343 VALIDATE_DESC(desc);
2344 /* Should be using gpio_get_value_cansleep() */
2345 WARN_ON(desc->gdev->chip->can_sleep);
2346 return _gpiod_get_raw_value(desc);
2348 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2351 * gpiod_get_value() - return a gpio's value
2352 * @desc: gpio whose value will be returned
2354 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2355 * account, or negative errno on failure.
2357 * This function should be called from contexts where we cannot sleep, and will
2358 * complain if the GPIO chip functions potentially sleep.
2360 int gpiod_get_value(const struct gpio_desc *desc)
2364 VALIDATE_DESC(desc);
2365 /* Should be using gpio_get_value_cansleep() */
2366 WARN_ON(desc->gdev->chip->can_sleep);
2368 value = _gpiod_get_raw_value(desc);
2372 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2377 EXPORT_SYMBOL_GPL(gpiod_get_value);
2380 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
2381 * @desc: gpio descriptor whose state need to be set.
2382 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2384 static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
2387 struct gpio_chip *chip = desc->gdev->chip;
2388 int offset = gpio_chip_hwgpio(desc);
2391 err = chip->direction_input(chip, offset);
2393 clear_bit(FLAG_IS_OUT, &desc->flags);
2395 err = chip->direction_output(chip, offset, 0);
2397 set_bit(FLAG_IS_OUT, &desc->flags);
2399 trace_gpio_direction(desc_to_gpio(desc), value, err);
2402 "%s: Error in set_value for open drain err %d\n",
2407 * _gpio_set_open_source_value() - Set the open source gpio's value.
2408 * @desc: gpio descriptor whose state need to be set.
2409 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2411 static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
2414 struct gpio_chip *chip = desc->gdev->chip;
2415 int offset = gpio_chip_hwgpio(desc);
2418 err = chip->direction_output(chip, offset, 1);
2420 set_bit(FLAG_IS_OUT, &desc->flags);
2422 err = chip->direction_input(chip, offset);
2424 clear_bit(FLAG_IS_OUT, &desc->flags);
2426 trace_gpio_direction(desc_to_gpio(desc), !value, err);
2429 "%s: Error in set_value for open source err %d\n",
2433 static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
2435 struct gpio_chip *chip;
2437 chip = desc->gdev->chip;
2438 trace_gpio_value(desc_to_gpio(desc), 0, value);
2439 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
2440 _gpio_set_open_drain_value(desc, value);
2441 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
2442 _gpio_set_open_source_value(desc, value);
2444 chip->set(chip, gpio_chip_hwgpio(desc), value);
2448 * set multiple outputs on the same chip;
2449 * use the chip's set_multiple function if available;
2450 * otherwise set the outputs sequentially;
2451 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2452 * defines which outputs are to be changed
2453 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2454 * defines the values the outputs specified by mask are to be set to
2456 static void gpio_chip_set_multiple(struct gpio_chip *chip,
2457 unsigned long *mask, unsigned long *bits)
2459 if (chip->set_multiple) {
2460 chip->set_multiple(chip, mask, bits);
2463 for (i = 0; i < chip->ngpio; i++) {
2464 if (mask[BIT_WORD(i)] == 0) {
2465 /* no more set bits in this mask word;
2466 * skip ahead to the next word */
2467 i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1;
2470 /* set outputs if the corresponding mask bit is set */
2471 if (__test_and_clear_bit(i, mask))
2472 chip->set(chip, i, test_bit(i, bits));
2477 void gpiod_set_array_value_complex(bool raw, bool can_sleep,
2478 unsigned int array_size,
2479 struct gpio_desc **desc_array,
2484 while (i < array_size) {
2485 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2486 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
2487 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
2491 WARN_ON(chip->can_sleep);
2493 memset(mask, 0, sizeof(mask));
2495 struct gpio_desc *desc = desc_array[i];
2496 int hwgpio = gpio_chip_hwgpio(desc);
2497 int value = value_array[i];
2499 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2501 trace_gpio_value(desc_to_gpio(desc), 0, value);
2503 * collect all normal outputs belonging to the same chip
2504 * open drain and open source outputs are set individually
2506 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2507 _gpio_set_open_drain_value(desc, value);
2508 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2509 _gpio_set_open_source_value(desc, value);
2511 __set_bit(hwgpio, mask);
2513 __set_bit(hwgpio, bits);
2515 __clear_bit(hwgpio, bits);
2519 } while ((i < array_size) &&
2520 (desc_array[i]->gdev->chip == chip));
2521 /* push collected bits to outputs */
2523 gpio_chip_set_multiple(chip, mask, bits);
2528 * gpiod_set_raw_value() - assign a gpio's raw value
2529 * @desc: gpio whose value will be assigned
2530 * @value: value to assign
2532 * Set the raw value of the GPIO, i.e. the value of its physical line without
2533 * regard for its ACTIVE_LOW status.
2535 * This function should be called from contexts where we cannot sleep, and will
2536 * complain if the GPIO chip functions potentially sleep.
2538 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
2540 VALIDATE_DESC_VOID(desc);
2541 /* Should be using gpiod_set_value_cansleep() */
2542 WARN_ON(desc->gdev->chip->can_sleep);
2543 _gpiod_set_raw_value(desc, value);
2545 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
2548 * gpiod_set_value() - assign a gpio's value
2549 * @desc: gpio whose value will be assigned
2550 * @value: value to assign
2552 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2555 * This function should be called from contexts where we cannot sleep, and will
2556 * complain if the GPIO chip functions potentially sleep.
2558 void gpiod_set_value(struct gpio_desc *desc, int value)
2560 VALIDATE_DESC_VOID(desc);
2561 /* Should be using gpiod_set_value_cansleep() */
2562 WARN_ON(desc->gdev->chip->can_sleep);
2563 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2565 _gpiod_set_raw_value(desc, value);
2567 EXPORT_SYMBOL_GPL(gpiod_set_value);
2570 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
2571 * @array_size: number of elements in the descriptor / value arrays
2572 * @desc_array: array of GPIO descriptors whose values will be assigned
2573 * @value_array: array of values to assign
2575 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2576 * without regard for their ACTIVE_LOW status.
2578 * This function should be called from contexts where we cannot sleep, and will
2579 * complain if the GPIO chip functions potentially sleep.
2581 void gpiod_set_raw_array_value(unsigned int array_size,
2582 struct gpio_desc **desc_array, int *value_array)
2586 gpiod_set_array_value_complex(true, false, array_size, desc_array,
2589 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
2592 * gpiod_set_array_value() - assign values to an array of GPIOs
2593 * @array_size: number of elements in the descriptor / value arrays
2594 * @desc_array: array of GPIO descriptors whose values will be assigned
2595 * @value_array: array of values to assign
2597 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2600 * This function should be called from contexts where we cannot sleep, and will
2601 * complain if the GPIO chip functions potentially sleep.
2603 void gpiod_set_array_value(unsigned int array_size,
2604 struct gpio_desc **desc_array, int *value_array)
2608 gpiod_set_array_value_complex(false, false, array_size, desc_array,
2611 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
2614 * gpiod_cansleep() - report whether gpio value access may sleep
2615 * @desc: gpio to check
2618 int gpiod_cansleep(const struct gpio_desc *desc)
2620 VALIDATE_DESC(desc);
2621 return desc->gdev->chip->can_sleep;
2623 EXPORT_SYMBOL_GPL(gpiod_cansleep);
2626 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
2627 * @desc: gpio whose IRQ will be returned (already requested)
2629 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
2632 int gpiod_to_irq(const struct gpio_desc *desc)
2634 struct gpio_chip *chip;
2638 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
2639 * requires this function to not return zero on an invalid descriptor
2640 * but rather a negative error number.
2642 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
2645 chip = desc->gdev->chip;
2646 offset = gpio_chip_hwgpio(desc);
2648 int retirq = chip->to_irq(chip, offset);
2650 /* Zero means NO_IRQ */
2658 EXPORT_SYMBOL_GPL(gpiod_to_irq);
2661 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
2662 * @chip: the chip the GPIO to lock belongs to
2663 * @offset: the offset of the GPIO to lock as IRQ
2665 * This is used directly by GPIO drivers that want to lock down
2666 * a certain GPIO line to be used for IRQs.
2668 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
2670 struct gpio_desc *desc;
2672 desc = gpiochip_get_desc(chip, offset);
2674 return PTR_ERR(desc);
2676 /* Flush direction if something changed behind our back */
2677 if (chip->get_direction) {
2678 int dir = chip->get_direction(chip, offset);
2681 clear_bit(FLAG_IS_OUT, &desc->flags);
2683 set_bit(FLAG_IS_OUT, &desc->flags);
2686 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
2688 "%s: tried to flag a GPIO set as output for IRQ\n",
2693 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
2696 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
2699 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
2700 * @chip: the chip the GPIO to lock belongs to
2701 * @offset: the offset of the GPIO to lock as IRQ
2703 * This is used directly by GPIO drivers that want to indicate
2704 * that a certain GPIO is no longer used exclusively for IRQ.
2706 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
2708 if (offset >= chip->ngpio)
2711 clear_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2713 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
2715 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
2717 if (offset >= chip->ngpio)
2720 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2722 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
2724 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
2726 if (offset >= chip->ngpio)
2729 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
2731 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
2733 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
2735 if (offset >= chip->ngpio)
2738 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
2740 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
2743 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2744 * @desc: gpio whose value will be returned
2746 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2747 * its ACTIVE_LOW status, or negative errno on failure.
2749 * This function is to be called from contexts that can sleep.
2751 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
2753 might_sleep_if(extra_checks);
2754 VALIDATE_DESC(desc);
2755 return _gpiod_get_raw_value(desc);
2757 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
2760 * gpiod_get_value_cansleep() - return a gpio's value
2761 * @desc: gpio whose value will be returned
2763 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2764 * account, or negative errno on failure.
2766 * This function is to be called from contexts that can sleep.
2768 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
2772 might_sleep_if(extra_checks);
2773 VALIDATE_DESC(desc);
2774 value = _gpiod_get_raw_value(desc);
2778 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2783 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
2786 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2787 * @desc: gpio whose value will be assigned
2788 * @value: value to assign
2790 * Set the raw value of the GPIO, i.e. the value of its physical line without
2791 * regard for its ACTIVE_LOW status.
2793 * This function is to be called from contexts that can sleep.
2795 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
2797 might_sleep_if(extra_checks);
2798 VALIDATE_DESC_VOID(desc);
2799 _gpiod_set_raw_value(desc, value);
2801 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
2804 * gpiod_set_value_cansleep() - assign a gpio's value
2805 * @desc: gpio whose value will be assigned
2806 * @value: value to assign
2808 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2811 * This function is to be called from contexts that can sleep.
2813 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
2815 might_sleep_if(extra_checks);
2816 VALIDATE_DESC_VOID(desc);
2817 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2819 _gpiod_set_raw_value(desc, value);
2821 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
2824 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2825 * @array_size: number of elements in the descriptor / value arrays
2826 * @desc_array: array of GPIO descriptors whose values will be assigned
2827 * @value_array: array of values to assign
2829 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2830 * without regard for their ACTIVE_LOW status.
2832 * This function is to be called from contexts that can sleep.
2834 void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
2835 struct gpio_desc **desc_array,
2838 might_sleep_if(extra_checks);
2841 gpiod_set_array_value_complex(true, true, array_size, desc_array,
2844 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
2847 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2848 * @array_size: number of elements in the descriptor / value arrays
2849 * @desc_array: array of GPIO descriptors whose values will be assigned
2850 * @value_array: array of values to assign
2852 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2855 * This function is to be called from contexts that can sleep.
2857 void gpiod_set_array_value_cansleep(unsigned int array_size,
2858 struct gpio_desc **desc_array,
2861 might_sleep_if(extra_checks);
2864 gpiod_set_array_value_complex(false, true, array_size, desc_array,
2867 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
2870 * gpiod_add_lookup_table() - register GPIO device consumers
2871 * @table: table of consumers to register
2873 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
2875 mutex_lock(&gpio_lookup_lock);
2877 list_add_tail(&table->list, &gpio_lookup_list);
2879 mutex_unlock(&gpio_lookup_lock);
2883 * gpiod_remove_lookup_table() - unregister GPIO device consumers
2884 * @table: table of consumers to unregister
2886 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
2888 mutex_lock(&gpio_lookup_lock);
2890 list_del(&table->list);
2892 mutex_unlock(&gpio_lookup_lock);
2895 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
2897 const char *dev_id = dev ? dev_name(dev) : NULL;
2898 struct gpiod_lookup_table *table;
2900 mutex_lock(&gpio_lookup_lock);
2902 list_for_each_entry(table, &gpio_lookup_list, list) {
2903 if (table->dev_id && dev_id) {
2905 * Valid strings on both ends, must be identical to have
2908 if (!strcmp(table->dev_id, dev_id))
2912 * One of the pointers is NULL, so both must be to have
2915 if (dev_id == table->dev_id)
2922 mutex_unlock(&gpio_lookup_lock);
2926 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
2928 enum gpio_lookup_flags *flags)
2930 struct gpio_desc *desc = ERR_PTR(-ENOENT);
2931 struct gpiod_lookup_table *table;
2932 struct gpiod_lookup *p;
2934 table = gpiod_find_lookup_table(dev);
2938 for (p = &table->table[0]; p->chip_label; p++) {
2939 struct gpio_chip *chip;
2941 /* idx must always match exactly */
2945 /* If the lookup entry has a con_id, require exact match */
2946 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
2949 chip = find_chip_by_name(p->chip_label);
2952 dev_err(dev, "cannot find GPIO chip %s\n",
2954 return ERR_PTR(-ENODEV);
2957 if (chip->ngpio <= p->chip_hwnum) {
2959 "requested GPIO %d is out of range [0..%d] for chip %s\n",
2960 idx, chip->ngpio, chip->label);
2961 return ERR_PTR(-EINVAL);
2964 desc = gpiochip_get_desc(chip, p->chip_hwnum);
2973 static int dt_gpio_count(struct device *dev, const char *con_id)
2979 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
2981 snprintf(propname, sizeof(propname), "%s-%s",
2982 con_id, gpio_suffixes[i]);
2984 snprintf(propname, sizeof(propname), "%s",
2987 ret = of_gpio_named_count(dev->of_node, propname);
2994 static int platform_gpio_count(struct device *dev, const char *con_id)
2996 struct gpiod_lookup_table *table;
2997 struct gpiod_lookup *p;
2998 unsigned int count = 0;
3000 table = gpiod_find_lookup_table(dev);
3004 for (p = &table->table[0]; p->chip_label; p++) {
3005 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3006 (!con_id && !p->con_id))
3016 * gpiod_count - return the number of GPIOs associated with a device / function
3017 * or -ENOENT if no GPIO has been assigned to the requested function
3018 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3019 * @con_id: function within the GPIO consumer
3021 int gpiod_count(struct device *dev, const char *con_id)
3023 int count = -ENOENT;
3025 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
3026 count = dt_gpio_count(dev, con_id);
3027 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
3028 count = acpi_gpio_count(dev, con_id);
3031 count = platform_gpio_count(dev, con_id);
3035 EXPORT_SYMBOL_GPL(gpiod_count);
3038 * gpiod_get - obtain a GPIO for a given GPIO function
3039 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3040 * @con_id: function within the GPIO consumer
3041 * @flags: optional GPIO initialization flags
3043 * Return the GPIO descriptor corresponding to the function con_id of device
3044 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3045 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3047 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3048 enum gpiod_flags flags)
3050 return gpiod_get_index(dev, con_id, 0, flags);
3052 EXPORT_SYMBOL_GPL(gpiod_get);
3055 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3056 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3057 * @con_id: function within the GPIO consumer
3058 * @flags: optional GPIO initialization flags
3060 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3061 * the requested function it will return NULL. This is convenient for drivers
3062 * that need to handle optional GPIOs.
3064 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3066 enum gpiod_flags flags)
3068 return gpiod_get_index_optional(dev, con_id, 0, flags);
3070 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3074 * gpiod_configure_flags - helper function to configure a given GPIO
3075 * @desc: gpio whose value will be assigned
3076 * @con_id: function within the GPIO consumer
3077 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3079 * @dflags: gpiod_flags - optional GPIO initialization flags
3081 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3082 * requested function and/or index, or another IS_ERR() code if an error
3083 * occurred while trying to acquire the GPIO.
3085 static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3086 unsigned long lflags, enum gpiod_flags dflags)
3090 if (lflags & GPIO_ACTIVE_LOW)
3091 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3092 if (lflags & GPIO_OPEN_DRAIN)
3093 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3094 if (lflags & GPIO_OPEN_SOURCE)
3095 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3097 /* No particular flag request, return here... */
3098 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3099 pr_debug("no flags found for %s\n", con_id);
3104 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3105 status = gpiod_direction_output(desc,
3106 dflags & GPIOD_FLAGS_BIT_DIR_VAL);
3108 status = gpiod_direction_input(desc);
3114 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3115 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3116 * @con_id: function within the GPIO consumer
3117 * @idx: index of the GPIO to obtain in the consumer
3118 * @flags: optional GPIO initialization flags
3120 * This variant of gpiod_get() allows to access GPIOs other than the first
3121 * defined one for functions that define several GPIOs.
3123 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3124 * requested function and/or index, or another IS_ERR() code if an error
3125 * occurred while trying to acquire the GPIO.
3127 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3130 enum gpiod_flags flags)
3132 struct gpio_desc *desc = NULL;
3134 enum gpio_lookup_flags lookupflags = 0;
3136 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3139 /* Using device tree? */
3140 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
3141 dev_dbg(dev, "using device tree for GPIO lookup\n");
3142 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3143 } else if (ACPI_COMPANION(dev)) {
3144 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3145 desc = acpi_find_gpio(dev, con_id, idx, flags, &lookupflags);
3150 * Either we are not using DT or ACPI, or their lookup did not return
3151 * a result. In that case, use platform lookup as a fallback.
3153 if (!desc || desc == ERR_PTR(-ENOENT)) {
3154 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3155 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3159 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
3163 status = gpiod_request(desc, con_id);
3165 return ERR_PTR(status);
3167 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3169 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3171 return ERR_PTR(status);
3176 EXPORT_SYMBOL_GPL(gpiod_get_index);
3179 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3180 * @fwnode: handle of the firmware node
3181 * @propname: name of the firmware property representing the GPIO
3183 * This function can be used for drivers that get their configuration
3186 * Function properly finds the corresponding GPIO using whatever is the
3187 * underlying firmware interface and then makes sure that the GPIO
3188 * descriptor is requested before it is returned to the caller.
3190 * In case of error an ERR_PTR() is returned.
3192 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
3193 const char *propname)
3195 struct gpio_desc *desc = ERR_PTR(-ENODEV);
3196 bool active_low = false;
3197 bool single_ended = false;
3201 return ERR_PTR(-EINVAL);
3203 if (is_of_node(fwnode)) {
3204 enum of_gpio_flags flags;
3206 desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0,
3208 if (!IS_ERR(desc)) {
3209 active_low = flags & OF_GPIO_ACTIVE_LOW;
3210 single_ended = flags & OF_GPIO_SINGLE_ENDED;
3212 } else if (is_acpi_node(fwnode)) {
3213 struct acpi_gpio_info info;
3215 desc = acpi_node_get_gpiod(fwnode, propname, 0, &info);
3217 active_low = info.polarity == GPIO_ACTIVE_LOW;
3223 ret = gpiod_request(desc, NULL);
3225 return ERR_PTR(ret);
3228 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3232 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3234 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3239 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
3242 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
3244 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3245 * @con_id: function within the GPIO consumer
3246 * @index: index of the GPIO to obtain in the consumer
3247 * @flags: optional GPIO initialization flags
3249 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
3250 * specified index was assigned to the requested function it will return NULL.
3251 * This is convenient for drivers that need to handle optional GPIOs.
3253 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
3256 enum gpiod_flags flags)
3258 struct gpio_desc *desc;
3260 desc = gpiod_get_index(dev, con_id, index, flags);
3262 if (PTR_ERR(desc) == -ENOENT)
3268 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
3271 * gpiod_hog - Hog the specified GPIO desc given the provided flags
3272 * @desc: gpio whose value will be assigned
3273 * @name: gpio line name
3274 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3276 * @dflags: gpiod_flags - optional GPIO initialization flags
3278 int gpiod_hog(struct gpio_desc *desc, const char *name,
3279 unsigned long lflags, enum gpiod_flags dflags)
3281 struct gpio_chip *chip;
3282 struct gpio_desc *local_desc;
3286 chip = gpiod_to_chip(desc);
3287 hwnum = gpio_chip_hwgpio(desc);
3289 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
3290 if (IS_ERR(local_desc)) {
3291 status = PTR_ERR(local_desc);
3292 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
3293 name, chip->label, hwnum, status);
3297 status = gpiod_configure_flags(desc, name, lflags, dflags);
3299 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
3300 name, chip->label, hwnum, status);
3301 gpiochip_free_own_desc(desc);
3305 /* Mark GPIO as hogged so it can be identified and removed later */
3306 set_bit(FLAG_IS_HOGGED, &desc->flags);
3308 pr_info("GPIO line %d (%s) hogged as %s%s\n",
3309 desc_to_gpio(desc), name,
3310 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
3311 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
3312 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
3318 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
3319 * @chip: gpio chip to act on
3321 * This is only used by of_gpiochip_remove to free hogged gpios
3323 static void gpiochip_free_hogs(struct gpio_chip *chip)
3327 for (id = 0; id < chip->ngpio; id++) {
3328 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
3329 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
3334 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
3335 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3336 * @con_id: function within the GPIO consumer
3337 * @flags: optional GPIO initialization flags
3339 * This function acquires all the GPIOs defined under a given function.
3341 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
3342 * no GPIO has been assigned to the requested function, or another IS_ERR()
3343 * code if an error occurred while trying to acquire the GPIOs.
3345 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
3347 enum gpiod_flags flags)
3349 struct gpio_desc *desc;
3350 struct gpio_descs *descs;
3353 count = gpiod_count(dev, con_id);
3355 return ERR_PTR(count);
3357 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
3360 return ERR_PTR(-ENOMEM);
3362 for (descs->ndescs = 0; descs->ndescs < count; ) {
3363 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
3365 gpiod_put_array(descs);
3366 return ERR_CAST(desc);
3368 descs->desc[descs->ndescs] = desc;
3373 EXPORT_SYMBOL_GPL(gpiod_get_array);
3376 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
3378 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3379 * @con_id: function within the GPIO consumer
3380 * @flags: optional GPIO initialization flags
3382 * This is equivalent to gpiod_get_array(), except that when no GPIO was
3383 * assigned to the requested function it will return NULL.
3385 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
3387 enum gpiod_flags flags)
3389 struct gpio_descs *descs;
3391 descs = gpiod_get_array(dev, con_id, flags);
3392 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
3397 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
3400 * gpiod_put - dispose of a GPIO descriptor
3401 * @desc: GPIO descriptor to dispose of
3403 * No descriptor can be used after gpiod_put() has been called on it.
3405 void gpiod_put(struct gpio_desc *desc)
3409 EXPORT_SYMBOL_GPL(gpiod_put);
3412 * gpiod_put_array - dispose of multiple GPIO descriptors
3413 * @descs: struct gpio_descs containing an array of descriptors
3415 void gpiod_put_array(struct gpio_descs *descs)
3419 for (i = 0; i < descs->ndescs; i++)
3420 gpiod_put(descs->desc[i]);
3424 EXPORT_SYMBOL_GPL(gpiod_put_array);
3426 static int __init gpiolib_dev_init(void)
3430 /* Register GPIO sysfs bus */
3431 ret = bus_register(&gpio_bus_type);
3433 pr_err("gpiolib: could not register GPIO bus type\n");
3437 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
3439 pr_err("gpiolib: failed to allocate char dev region\n");
3440 bus_unregister(&gpio_bus_type);
3442 gpiolib_initialized = true;
3443 gpiochip_setup_devs();
3447 core_initcall(gpiolib_dev_init);
3449 #ifdef CONFIG_DEBUG_FS
3451 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
3454 struct gpio_chip *chip = gdev->chip;
3455 unsigned gpio = gdev->base;
3456 struct gpio_desc *gdesc = &gdev->descs[0];
3460 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
3461 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
3463 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
3469 gpiod_get_direction(gdesc);
3470 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
3471 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
3472 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
3473 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
3474 is_out ? "out" : "in ",
3476 ? (chip->get(chip, i) ? "hi" : "lo")
3478 is_irq ? "IRQ" : " ");
3479 seq_printf(s, "\n");
3483 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
3485 unsigned long flags;
3486 struct gpio_device *gdev = NULL;
3487 loff_t index = *pos;
3491 spin_lock_irqsave(&gpio_lock, flags);
3492 list_for_each_entry(gdev, &gpio_devices, list)
3494 spin_unlock_irqrestore(&gpio_lock, flags);
3497 spin_unlock_irqrestore(&gpio_lock, flags);
3502 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
3504 unsigned long flags;
3505 struct gpio_device *gdev = v;
3508 spin_lock_irqsave(&gpio_lock, flags);
3509 if (list_is_last(&gdev->list, &gpio_devices))
3512 ret = list_entry(gdev->list.next, struct gpio_device, list);
3513 spin_unlock_irqrestore(&gpio_lock, flags);
3521 static void gpiolib_seq_stop(struct seq_file *s, void *v)
3525 static int gpiolib_seq_show(struct seq_file *s, void *v)
3527 struct gpio_device *gdev = v;
3528 struct gpio_chip *chip = gdev->chip;
3529 struct device *parent;
3532 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
3533 dev_name(&gdev->dev));
3537 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
3538 dev_name(&gdev->dev),
3539 gdev->base, gdev->base + gdev->ngpio - 1);
3540 parent = chip->parent;
3542 seq_printf(s, ", parent: %s/%s",
3543 parent->bus ? parent->bus->name : "no-bus",
3546 seq_printf(s, ", %s", chip->label);
3547 if (chip->can_sleep)
3548 seq_printf(s, ", can sleep");
3549 seq_printf(s, ":\n");
3552 chip->dbg_show(s, chip);
3554 gpiolib_dbg_show(s, gdev);
3559 static const struct seq_operations gpiolib_seq_ops = {
3560 .start = gpiolib_seq_start,
3561 .next = gpiolib_seq_next,
3562 .stop = gpiolib_seq_stop,
3563 .show = gpiolib_seq_show,
3566 static int gpiolib_open(struct inode *inode, struct file *file)
3568 return seq_open(file, &gpiolib_seq_ops);
3571 static const struct file_operations gpiolib_operations = {
3572 .owner = THIS_MODULE,
3573 .open = gpiolib_open,
3575 .llseek = seq_lseek,
3576 .release = seq_release,
3579 static int __init gpiolib_debugfs_init(void)
3581 /* /sys/kernel/debug/gpio */
3582 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
3583 NULL, NULL, &gpiolib_operations);
3586 subsys_initcall(gpiolib_debugfs_init);
3588 #endif /* DEBUG_FS */