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 memset(&ghd, 0, sizeof(ghd));
349 /* TODO: check if descriptors are really input */
350 for (i = 0; i < lh->numdescs; i++) {
351 val = gpiod_get_value_cansleep(lh->descs[i]);
357 if (copy_to_user(ip, &ghd, sizeof(ghd)))
361 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
362 int vals[GPIOHANDLES_MAX];
364 /* TODO: check if descriptors are really output */
365 if (copy_from_user(&ghd, ip, sizeof(ghd)))
368 /* Clamp all values to [0,1] */
369 for (i = 0; i < lh->numdescs; i++)
370 vals[i] = !!ghd.values[i];
372 /* Reuse the array setting function */
373 gpiod_set_array_value_complex(false,
384 static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
387 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
391 static int linehandle_release(struct inode *inode, struct file *filep)
393 struct linehandle_state *lh = filep->private_data;
394 struct gpio_device *gdev = lh->gdev;
397 for (i = 0; i < lh->numdescs; i++)
398 gpiod_free(lh->descs[i]);
401 put_device(&gdev->dev);
405 static const struct file_operations linehandle_fileops = {
406 .release = linehandle_release,
407 .owner = THIS_MODULE,
408 .llseek = noop_llseek,
409 .unlocked_ioctl = linehandle_ioctl,
411 .compat_ioctl = linehandle_ioctl_compat,
415 static int linehandle_create(struct gpio_device *gdev, void __user *ip)
417 struct gpiohandle_request handlereq;
418 struct linehandle_state *lh;
421 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
423 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
426 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
430 get_device(&gdev->dev);
432 /* Make sure this is terminated */
433 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
434 if (strlen(handlereq.consumer_label)) {
435 lh->label = kstrdup(handlereq.consumer_label,
443 /* Request each GPIO */
444 for (i = 0; i < handlereq.lines; i++) {
445 u32 offset = handlereq.lineoffsets[i];
446 u32 lflags = handlereq.flags;
447 struct gpio_desc *desc;
449 if (offset >= gdev->ngpio) {
454 desc = &gdev->descs[offset];
455 ret = gpiod_request(desc, lh->label);
460 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
461 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
462 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
463 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
464 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
465 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
468 * Lines have to be requested explicitly for input
469 * or output, else the line will be treated "as is".
471 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
472 int val = !!handlereq.default_values[i];
474 ret = gpiod_direction_output(desc, val);
477 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
478 ret = gpiod_direction_input(desc);
482 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
485 /* Let i point at the last handle */
487 lh->numdescs = handlereq.lines;
489 fd = anon_inode_getfd("gpio-linehandle",
492 O_RDONLY | O_CLOEXEC);
499 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
504 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
511 gpiod_free(lh->descs[i]);
515 put_device(&gdev->dev);
520 * GPIO line event management
524 * struct lineevent_state - contains the state of a userspace event
525 * @gdev: the GPIO device the event pertains to
526 * @label: consumer label used to tag descriptors
527 * @desc: the GPIO descriptor held by this event
528 * @eflags: the event flags this line was requested with
529 * @irq: the interrupt that trigger in response to events on this GPIO
530 * @wait: wait queue that handles blocking reads of events
531 * @events: KFIFO for the GPIO events
532 * @read_lock: mutex lock to protect reads from colliding with adding
533 * new events to the FIFO
535 struct lineevent_state {
536 struct gpio_device *gdev;
538 struct gpio_desc *desc;
541 wait_queue_head_t wait;
542 DECLARE_KFIFO(events, struct gpioevent_data, 16);
543 struct mutex read_lock;
546 static unsigned int lineevent_poll(struct file *filep,
547 struct poll_table_struct *wait)
549 struct lineevent_state *le = filep->private_data;
550 unsigned int events = 0;
552 poll_wait(filep, &le->wait, wait);
554 if (!kfifo_is_empty(&le->events))
555 events = POLLIN | POLLRDNORM;
561 static ssize_t lineevent_read(struct file *filep,
566 struct lineevent_state *le = filep->private_data;
570 if (count < sizeof(struct gpioevent_data))
574 if (kfifo_is_empty(&le->events)) {
575 if (filep->f_flags & O_NONBLOCK)
578 ret = wait_event_interruptible(le->wait,
579 !kfifo_is_empty(&le->events));
584 if (mutex_lock_interruptible(&le->read_lock))
586 ret = kfifo_to_user(&le->events, buf, count, &copied);
587 mutex_unlock(&le->read_lock);
593 * If we couldn't read anything from the fifo (a different
594 * thread might have been faster) we either return -EAGAIN if
595 * the file descriptor is non-blocking, otherwise we go back to
596 * sleep and wait for more data to arrive.
598 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
601 } while (copied == 0);
606 static int lineevent_release(struct inode *inode, struct file *filep)
608 struct lineevent_state *le = filep->private_data;
609 struct gpio_device *gdev = le->gdev;
611 free_irq(le->irq, le);
612 gpiod_free(le->desc);
615 put_device(&gdev->dev);
619 static long lineevent_ioctl(struct file *filep, unsigned int cmd,
622 struct lineevent_state *le = filep->private_data;
623 void __user *ip = (void __user *)arg;
624 struct gpiohandle_data ghd;
627 * We can get the value for an event line but not set it,
628 * because it is input by definition.
630 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
633 memset(&ghd, 0, sizeof(ghd));
635 val = gpiod_get_value_cansleep(le->desc);
640 if (copy_to_user(ip, &ghd, sizeof(ghd)))
649 static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
652 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
656 static const struct file_operations lineevent_fileops = {
657 .release = lineevent_release,
658 .read = lineevent_read,
659 .poll = lineevent_poll,
660 .owner = THIS_MODULE,
661 .llseek = noop_llseek,
662 .unlocked_ioctl = lineevent_ioctl,
664 .compat_ioctl = lineevent_ioctl_compat,
668 static irqreturn_t lineevent_irq_thread(int irq, void *p)
670 struct lineevent_state *le = p;
671 struct gpioevent_data ge;
674 ge.timestamp = ktime_get_real_ns();
676 if (le->eflags & GPIOEVENT_REQUEST_BOTH_EDGES) {
677 int level = gpiod_get_value_cansleep(le->desc);
680 /* Emit low-to-high event */
681 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
683 /* Emit high-to-low event */
684 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
685 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
686 /* Emit low-to-high event */
687 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
688 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
689 /* Emit high-to-low event */
690 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
695 ret = kfifo_put(&le->events, ge);
697 wake_up_poll(&le->wait, POLLIN);
702 static int lineevent_create(struct gpio_device *gdev, void __user *ip)
704 struct gpioevent_request eventreq;
705 struct lineevent_state *le;
706 struct gpio_desc *desc;
714 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
717 le = kzalloc(sizeof(*le), GFP_KERNEL);
721 get_device(&gdev->dev);
723 /* Make sure this is terminated */
724 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
725 if (strlen(eventreq.consumer_label)) {
726 le->label = kstrdup(eventreq.consumer_label,
734 offset = eventreq.lineoffset;
735 lflags = eventreq.handleflags;
736 eflags = eventreq.eventflags;
738 if (offset >= gdev->ngpio) {
743 /* This is just wrong: we don't look for events on output lines */
744 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
749 desc = &gdev->descs[offset];
750 ret = gpiod_request(desc, le->label);
756 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
757 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
758 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
759 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
760 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
761 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
763 ret = gpiod_direction_input(desc);
767 le->irq = gpiod_to_irq(desc);
773 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
774 irqflags |= IRQF_TRIGGER_RISING;
775 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
776 irqflags |= IRQF_TRIGGER_FALLING;
777 irqflags |= IRQF_ONESHOT;
778 irqflags |= IRQF_SHARED;
780 INIT_KFIFO(le->events);
781 init_waitqueue_head(&le->wait);
782 mutex_init(&le->read_lock);
784 /* Request a thread to read the events */
785 ret = request_threaded_irq(le->irq,
787 lineevent_irq_thread,
794 fd = anon_inode_getfd("gpio-event",
797 O_RDONLY | O_CLOEXEC);
804 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
812 free_irq(le->irq, le);
814 gpiod_free(le->desc);
819 put_device(&gdev->dev);
824 * gpio_ioctl() - ioctl handler for the GPIO chardev
826 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
828 struct gpio_device *gdev = filp->private_data;
829 struct gpio_chip *chip = gdev->chip;
830 void __user *ip = (void __user *)arg;
832 /* We fail any subsequent ioctl():s when the chip is gone */
836 /* Fill in the struct and pass to userspace */
837 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
838 struct gpiochip_info chipinfo;
840 memset(&chipinfo, 0, sizeof(chipinfo));
842 strncpy(chipinfo.name, dev_name(&gdev->dev),
843 sizeof(chipinfo.name));
844 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
845 strncpy(chipinfo.label, gdev->label,
846 sizeof(chipinfo.label));
847 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
848 chipinfo.lines = gdev->ngpio;
849 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
852 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
853 struct gpioline_info lineinfo;
854 struct gpio_desc *desc;
856 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
858 if (lineinfo.line_offset >= gdev->ngpio)
861 desc = &gdev->descs[lineinfo.line_offset];
863 strncpy(lineinfo.name, desc->name,
864 sizeof(lineinfo.name));
865 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
867 lineinfo.name[0] = '\0';
870 strncpy(lineinfo.consumer, desc->label,
871 sizeof(lineinfo.consumer));
872 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
874 lineinfo.consumer[0] = '\0';
878 * Userspace only need to know that the kernel is using
879 * this GPIO so it can't use it.
882 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
883 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
884 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
885 test_bit(FLAG_EXPORT, &desc->flags) ||
886 test_bit(FLAG_SYSFS, &desc->flags))
887 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
888 if (test_bit(FLAG_IS_OUT, &desc->flags))
889 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
890 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
891 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
892 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
893 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
894 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
895 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
897 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
900 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
901 return linehandle_create(gdev, ip);
902 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
903 return lineevent_create(gdev, ip);
909 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
912 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
917 * gpio_chrdev_open() - open the chardev for ioctl operations
918 * @inode: inode for this chardev
919 * @filp: file struct for storing private data
920 * Returns 0 on success
922 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
924 struct gpio_device *gdev = container_of(inode->i_cdev,
925 struct gpio_device, chrdev);
927 /* Fail on open if the backing gpiochip is gone */
928 if (!gdev || !gdev->chip)
930 get_device(&gdev->dev);
931 filp->private_data = gdev;
936 * gpio_chrdev_release() - close chardev after ioctl operations
937 * @inode: inode for this chardev
938 * @filp: file struct for storing private data
939 * Returns 0 on success
941 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
943 struct gpio_device *gdev = container_of(inode->i_cdev,
944 struct gpio_device, chrdev);
948 put_device(&gdev->dev);
953 static const struct file_operations gpio_fileops = {
954 .release = gpio_chrdev_release,
955 .open = gpio_chrdev_open,
956 .owner = THIS_MODULE,
957 .llseek = noop_llseek,
958 .unlocked_ioctl = gpio_ioctl,
960 .compat_ioctl = gpio_ioctl_compat,
964 static void gpiodevice_release(struct device *dev)
966 struct gpio_device *gdev = dev_get_drvdata(dev);
968 list_del(&gdev->list);
969 ida_simple_remove(&gpio_ida, gdev->id);
975 static int gpiochip_setup_dev(struct gpio_device *gdev)
979 cdev_init(&gdev->chrdev, &gpio_fileops);
980 gdev->chrdev.owner = THIS_MODULE;
981 gdev->chrdev.kobj.parent = &gdev->dev.kobj;
982 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
983 status = cdev_add(&gdev->chrdev, gdev->dev.devt, 1);
985 chip_warn(gdev->chip, "failed to add char device %d:%d\n",
986 MAJOR(gpio_devt), gdev->id);
988 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
989 MAJOR(gpio_devt), gdev->id);
990 status = device_add(&gdev->dev);
992 goto err_remove_chardev;
994 status = gpiochip_sysfs_register(gdev);
996 goto err_remove_device;
998 /* From this point, the .release() function cleans up gpio_device */
999 gdev->dev.release = gpiodevice_release;
1000 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1001 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1002 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1007 device_del(&gdev->dev);
1009 cdev_del(&gdev->chrdev);
1013 static void gpiochip_setup_devs(void)
1015 struct gpio_device *gdev;
1018 list_for_each_entry(gdev, &gpio_devices, list) {
1019 err = gpiochip_setup_dev(gdev);
1021 pr_err("%s: Failed to initialize gpio device (%d)\n",
1022 dev_name(&gdev->dev), err);
1027 * gpiochip_add_data() - register a gpio_chip
1028 * @chip: the chip to register, with chip->base initialized
1029 * Context: potentially before irqs will work
1031 * Returns a negative errno if the chip can't be registered, such as
1032 * because the chip->base is invalid or already associated with a
1033 * different chip. Otherwise it returns zero as a success code.
1035 * When gpiochip_add_data() is called very early during boot, so that GPIOs
1036 * can be freely used, the chip->parent device must be registered before
1037 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
1038 * for GPIOs will fail rudely.
1040 * gpiochip_add_data() must only be called after gpiolib initialization,
1041 * ie after core_initcall().
1043 * If chip->base is negative, this requests dynamic assignment of
1044 * a range of valid GPIOs.
1046 int gpiochip_add_data(struct gpio_chip *chip, void *data)
1048 unsigned long flags;
1051 int base = chip->base;
1052 struct gpio_device *gdev;
1055 * First: allocate and populate the internal stat container, and
1056 * set up the struct device.
1058 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1061 gdev->dev.bus = &gpio_bus_type;
1063 chip->gpiodev = gdev;
1065 gdev->dev.parent = chip->parent;
1066 gdev->dev.of_node = chip->parent->of_node;
1069 #ifdef CONFIG_OF_GPIO
1070 /* If the gpiochip has an assigned OF node this takes precedence */
1072 gdev->dev.of_node = chip->of_node;
1075 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1080 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1081 device_initialize(&gdev->dev);
1082 dev_set_drvdata(&gdev->dev, gdev);
1083 if (chip->parent && chip->parent->driver)
1084 gdev->owner = chip->parent->driver->owner;
1085 else if (chip->owner)
1086 /* TODO: remove chip->owner */
1087 gdev->owner = chip->owner;
1089 gdev->owner = THIS_MODULE;
1091 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1097 if (chip->ngpio == 0) {
1098 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1100 goto err_free_descs;
1104 gdev->label = kstrdup(chip->label, GFP_KERNEL);
1106 gdev->label = kstrdup("unknown", GFP_KERNEL);
1109 goto err_free_descs;
1112 gdev->ngpio = chip->ngpio;
1115 spin_lock_irqsave(&gpio_lock, flags);
1118 * TODO: this allocates a Linux GPIO number base in the global
1119 * GPIO numberspace for this chip. In the long run we want to
1120 * get *rid* of this numberspace and use only descriptors, but
1121 * it may be a pipe dream. It will not happen before we get rid
1122 * of the sysfs interface anyways.
1125 base = gpiochip_find_base(chip->ngpio);
1128 spin_unlock_irqrestore(&gpio_lock, flags);
1129 goto err_free_label;
1132 * TODO: it should not be necessary to reflect the assigned
1133 * base outside of the GPIO subsystem. Go over drivers and
1134 * see if anyone makes use of this, else drop this and assign
1141 status = gpiodev_add_to_list(gdev);
1143 spin_unlock_irqrestore(&gpio_lock, flags);
1144 goto err_free_label;
1147 spin_unlock_irqrestore(&gpio_lock, flags);
1149 for (i = 0; i < chip->ngpio; i++) {
1150 struct gpio_desc *desc = &gdev->descs[i];
1154 * REVISIT: most hardware initializes GPIOs as inputs
1155 * (often with pullups enabled) so power usage is
1156 * minimized. Linux code should set the gpio direction
1157 * first thing; but until it does, and in case
1158 * chip->get_direction is not set, we may expose the
1159 * wrong direction in sysfs.
1162 if (chip->get_direction) {
1164 * If we have .get_direction, set up the initial
1165 * direction flag from the hardware.
1167 int dir = chip->get_direction(chip, i);
1170 set_bit(FLAG_IS_OUT, &desc->flags);
1171 } else if (!chip->direction_input) {
1173 * If the chip lacks the .direction_input callback
1174 * we logically assume all lines are outputs.
1176 set_bit(FLAG_IS_OUT, &desc->flags);
1180 #ifdef CONFIG_PINCTRL
1181 INIT_LIST_HEAD(&gdev->pin_ranges);
1184 status = gpiochip_set_desc_names(chip);
1186 goto err_remove_from_list;
1188 status = gpiochip_irqchip_init_valid_mask(chip);
1190 goto err_remove_from_list;
1192 status = of_gpiochip_add(chip);
1194 goto err_remove_chip;
1196 acpi_gpiochip_add(chip);
1199 * By first adding the chardev, and then adding the device,
1200 * we get a device node entry in sysfs under
1201 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1202 * coldplug of device nodes and other udev business.
1203 * We can do this only if gpiolib has been initialized.
1204 * Otherwise, defer until later.
1206 if (gpiolib_initialized) {
1207 status = gpiochip_setup_dev(gdev);
1209 goto err_remove_chip;
1214 acpi_gpiochip_remove(chip);
1215 gpiochip_free_hogs(chip);
1216 of_gpiochip_remove(chip);
1217 gpiochip_irqchip_free_valid_mask(chip);
1218 err_remove_from_list:
1219 spin_lock_irqsave(&gpio_lock, flags);
1220 list_del(&gdev->list);
1221 spin_unlock_irqrestore(&gpio_lock, flags);
1227 ida_simple_remove(&gpio_ida, gdev->id);
1228 /* failures here can mean systems won't boot... */
1229 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
1230 gdev->base, gdev->base + gdev->ngpio - 1,
1231 chip->label ? : "generic");
1235 EXPORT_SYMBOL_GPL(gpiochip_add_data);
1238 * gpiochip_get_data() - get per-subdriver data for the chip
1240 void *gpiochip_get_data(struct gpio_chip *chip)
1242 return chip->gpiodev->data;
1244 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1247 * gpiochip_remove() - unregister a gpio_chip
1248 * @chip: the chip to unregister
1250 * A gpio_chip with any GPIOs still requested may not be removed.
1252 void gpiochip_remove(struct gpio_chip *chip)
1254 struct gpio_device *gdev = chip->gpiodev;
1255 struct gpio_desc *desc;
1256 unsigned long flags;
1258 bool requested = false;
1260 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1261 gpiochip_sysfs_unregister(gdev);
1262 /* Numb the device, cancelling all outstanding operations */
1264 gpiochip_irqchip_remove(chip);
1265 acpi_gpiochip_remove(chip);
1266 gpiochip_remove_pin_ranges(chip);
1267 gpiochip_free_hogs(chip);
1268 of_gpiochip_remove(chip);
1270 * We accept no more calls into the driver from this point, so
1271 * NULL the driver data pointer
1275 spin_lock_irqsave(&gpio_lock, flags);
1276 for (i = 0; i < gdev->ngpio; i++) {
1277 desc = &gdev->descs[i];
1278 if (test_bit(FLAG_REQUESTED, &desc->flags))
1281 spin_unlock_irqrestore(&gpio_lock, flags);
1284 dev_crit(&gdev->dev,
1285 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1288 * The gpiochip side puts its use of the device to rest here:
1289 * if there are no userspace clients, the chardev and device will
1290 * be removed, else it will be dangling until the last user is
1293 cdev_del(&gdev->chrdev);
1294 device_del(&gdev->dev);
1295 put_device(&gdev->dev);
1297 EXPORT_SYMBOL_GPL(gpiochip_remove);
1299 static void devm_gpio_chip_release(struct device *dev, void *res)
1301 struct gpio_chip *chip = *(struct gpio_chip **)res;
1303 gpiochip_remove(chip);
1306 static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
1309 struct gpio_chip **r = res;
1320 * devm_gpiochip_add_data() - Resource manager piochip_add_data()
1321 * @dev: the device pointer on which irq_chip belongs to.
1322 * @chip: the chip to register, with chip->base initialized
1323 * Context: potentially before irqs will work
1325 * Returns a negative errno if the chip can't be registered, such as
1326 * because the chip->base is invalid or already associated with a
1327 * different chip. Otherwise it returns zero as a success code.
1329 * The gpio chip automatically be released when the device is unbound.
1331 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1334 struct gpio_chip **ptr;
1337 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1342 ret = gpiochip_add_data(chip, data);
1349 devres_add(dev, ptr);
1353 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1356 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1357 * @dev: device for which which resource was allocated
1358 * @chip: the chip to remove
1360 * A gpio_chip with any GPIOs still requested may not be removed.
1362 void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
1366 ret = devres_release(dev, devm_gpio_chip_release,
1367 devm_gpio_chip_match, chip);
1371 EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
1374 * gpiochip_find() - iterator for locating a specific gpio_chip
1375 * @data: data to pass to match function
1376 * @callback: Callback function to check gpio_chip
1378 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1379 * determined by a user supplied @match callback. The callback should return
1380 * 0 if the device doesn't match and non-zero if it does. If the callback is
1381 * non-zero, this function will return to the caller and not iterate over any
1384 struct gpio_chip *gpiochip_find(void *data,
1385 int (*match)(struct gpio_chip *chip,
1388 struct gpio_device *gdev;
1389 struct gpio_chip *chip = NULL;
1390 unsigned long flags;
1392 spin_lock_irqsave(&gpio_lock, flags);
1393 list_for_each_entry(gdev, &gpio_devices, list)
1394 if (gdev->chip && match(gdev->chip, data)) {
1399 spin_unlock_irqrestore(&gpio_lock, flags);
1403 EXPORT_SYMBOL_GPL(gpiochip_find);
1405 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1407 const char *name = data;
1409 return !strcmp(chip->label, name);
1412 static struct gpio_chip *find_chip_by_name(const char *name)
1414 return gpiochip_find((void *)name, gpiochip_match_name);
1417 #ifdef CONFIG_GPIOLIB_IRQCHIP
1420 * The following is irqchip helper code for gpiochips.
1423 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1427 if (!gpiochip->irq_need_valid_mask)
1430 gpiochip->irq_valid_mask = kcalloc(BITS_TO_LONGS(gpiochip->ngpio),
1431 sizeof(long), GFP_KERNEL);
1432 if (!gpiochip->irq_valid_mask)
1435 /* Assume by default all GPIOs are valid */
1436 for (i = 0; i < gpiochip->ngpio; i++)
1437 set_bit(i, gpiochip->irq_valid_mask);
1442 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1444 kfree(gpiochip->irq_valid_mask);
1445 gpiochip->irq_valid_mask = NULL;
1448 static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1449 unsigned int offset)
1451 /* No mask means all valid */
1452 if (likely(!gpiochip->irq_valid_mask))
1454 return test_bit(offset, gpiochip->irq_valid_mask);
1458 * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
1459 * @gpiochip: the gpiochip to set the irqchip chain to
1460 * @irqchip: the irqchip to chain to the gpiochip
1461 * @parent_irq: the irq number corresponding to the parent IRQ for this
1463 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1464 * coming out of the gpiochip. If the interrupt is nested rather than
1465 * cascaded, pass NULL in this handler argument
1467 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1468 struct irq_chip *irqchip,
1470 irq_flow_handler_t parent_handler)
1472 unsigned int offset;
1474 if (!gpiochip->irqdomain) {
1475 chip_err(gpiochip, "called %s before setting up irqchip\n",
1480 if (parent_handler) {
1481 if (gpiochip->can_sleep) {
1483 "you cannot have chained interrupts on a "
1484 "chip that may sleep\n");
1488 * The parent irqchip is already using the chip_data for this
1489 * irqchip, so our callbacks simply use the handler_data.
1491 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1494 gpiochip->irq_parent = parent_irq;
1497 /* Set the parent IRQ for all affected IRQs */
1498 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1499 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1501 irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
1505 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1508 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1509 * @d: the irqdomain used by this irqchip
1510 * @irq: the global irq number used by this GPIO irqchip irq
1511 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1513 * This function will set up the mapping for a certain IRQ line on a
1514 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1515 * stored inside the gpiochip.
1517 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1518 irq_hw_number_t hwirq)
1520 struct gpio_chip *chip = d->host_data;
1522 irq_set_chip_data(irq, chip);
1524 * This lock class tells lockdep that GPIO irqs are in a different
1525 * category than their parents, so it won't report false recursion.
1527 irq_set_lockdep_class(irq, chip->lock_key);
1528 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
1529 /* Chips that can sleep need nested thread handlers */
1530 if (chip->can_sleep && !chip->irq_not_threaded)
1531 irq_set_nested_thread(irq, 1);
1532 irq_set_noprobe(irq);
1535 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1536 * is passed as default type.
1538 if (chip->irq_default_type != IRQ_TYPE_NONE)
1539 irq_set_irq_type(irq, chip->irq_default_type);
1544 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1546 struct gpio_chip *chip = d->host_data;
1548 if (chip->can_sleep)
1549 irq_set_nested_thread(irq, 0);
1550 irq_set_chip_and_handler(irq, NULL, NULL);
1551 irq_set_chip_data(irq, NULL);
1554 static const struct irq_domain_ops gpiochip_domain_ops = {
1555 .map = gpiochip_irq_map,
1556 .unmap = gpiochip_irq_unmap,
1557 /* Virtually all GPIO irqchips are twocell:ed */
1558 .xlate = irq_domain_xlate_twocell,
1561 static int gpiochip_irq_reqres(struct irq_data *d)
1563 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1565 if (!try_module_get(chip->gpiodev->owner))
1568 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
1570 "unable to lock HW IRQ %lu for IRQ\n",
1572 module_put(chip->gpiodev->owner);
1578 static void gpiochip_irq_relres(struct irq_data *d)
1580 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1582 gpiochip_unlock_as_irq(chip, d->hwirq);
1583 module_put(chip->gpiodev->owner);
1586 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1588 return irq_find_mapping(chip->irqdomain, offset);
1592 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1593 * @gpiochip: the gpiochip to remove the irqchip from
1595 * This is called only from gpiochip_remove()
1597 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1599 unsigned int offset;
1601 acpi_gpiochip_free_interrupts(gpiochip);
1603 if (gpiochip->irq_parent) {
1604 irq_set_chained_handler(gpiochip->irq_parent, NULL);
1605 irq_set_handler_data(gpiochip->irq_parent, NULL);
1608 /* Remove all IRQ mappings and delete the domain */
1609 if (gpiochip->irqdomain) {
1610 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1611 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1613 irq_dispose_mapping(
1614 irq_find_mapping(gpiochip->irqdomain, offset));
1616 irq_domain_remove(gpiochip->irqdomain);
1619 if (gpiochip->irqchip) {
1620 gpiochip->irqchip->irq_request_resources = NULL;
1621 gpiochip->irqchip->irq_release_resources = NULL;
1622 gpiochip->irqchip = NULL;
1625 gpiochip_irqchip_free_valid_mask(gpiochip);
1629 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
1630 * @gpiochip: the gpiochip to add the irqchip to
1631 * @irqchip: the irqchip to add to the gpiochip
1632 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1633 * allocate gpiochip irqs from
1634 * @handler: the irq handler to use (often a predefined irq core function)
1635 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1636 * to have the core avoid setting up any default type in the hardware.
1637 * @lock_key: lockdep class
1639 * This function closely associates a certain irqchip with a certain
1640 * gpiochip, providing an irq domain to translate the local IRQs to
1641 * global irqs in the gpiolib core, and making sure that the gpiochip
1642 * is passed as chip data to all related functions. Driver callbacks
1643 * need to use gpiochip_get_data() to get their local state containers back
1644 * from the gpiochip passed as chip data. An irqdomain will be stored
1645 * in the gpiochip that shall be used by the driver to handle IRQ number
1646 * translation. The gpiochip will need to be initialized and registered
1647 * before calling this function.
1649 * This function will handle two cell:ed simple IRQs and assumes all
1650 * the pins on the gpiochip can generate a unique IRQ. Everything else
1651 * need to be open coded.
1653 int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
1654 struct irq_chip *irqchip,
1655 unsigned int first_irq,
1656 irq_flow_handler_t handler,
1658 struct lock_class_key *lock_key)
1660 struct device_node *of_node;
1661 bool irq_base_set = false;
1662 unsigned int offset;
1663 unsigned irq_base = 0;
1665 if (!gpiochip || !irqchip)
1668 if (!gpiochip->parent) {
1669 pr_err("missing gpiochip .dev parent pointer\n");
1672 of_node = gpiochip->parent->of_node;
1673 #ifdef CONFIG_OF_GPIO
1675 * If the gpiochip has an assigned OF node this takes precedence
1676 * FIXME: get rid of this and use gpiochip->parent->of_node
1679 if (gpiochip->of_node)
1680 of_node = gpiochip->of_node;
1683 * Specifying a default trigger is a terrible idea if DT or ACPI is
1684 * used to configure the interrupts, as you may end-up with
1685 * conflicting triggers. Tell the user, and reset to NONE.
1687 if (WARN(of_node && type != IRQ_TYPE_NONE,
1688 "%s: Ignoring %d default trigger\n", of_node->full_name, type))
1689 type = IRQ_TYPE_NONE;
1690 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1691 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1692 "Ignoring %d default trigger\n", type);
1693 type = IRQ_TYPE_NONE;
1696 gpiochip->irqchip = irqchip;
1697 gpiochip->irq_handler = handler;
1698 gpiochip->irq_default_type = type;
1699 gpiochip->to_irq = gpiochip_to_irq;
1700 gpiochip->lock_key = lock_key;
1701 gpiochip->irqdomain = irq_domain_add_simple(of_node,
1702 gpiochip->ngpio, first_irq,
1703 &gpiochip_domain_ops, gpiochip);
1704 if (!gpiochip->irqdomain) {
1705 gpiochip->irqchip = NULL;
1710 * It is possible for a driver to override this, but only if the
1711 * alternative functions are both implemented.
1713 if (!irqchip->irq_request_resources &&
1714 !irqchip->irq_release_resources) {
1715 irqchip->irq_request_resources = gpiochip_irq_reqres;
1716 irqchip->irq_release_resources = gpiochip_irq_relres;
1720 * Prepare the mapping since the irqchip shall be orthogonal to
1721 * any gpiochip calls. If the first_irq was zero, this is
1722 * necessary to allocate descriptors for all IRQs.
1724 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1725 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1727 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
1728 if (!irq_base_set) {
1730 * Store the base into the gpiochip to be used when
1731 * unmapping the irqs.
1733 gpiochip->irq_base = irq_base;
1734 irq_base_set = true;
1738 acpi_gpiochip_request_interrupts(gpiochip);
1742 EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add);
1744 #else /* CONFIG_GPIOLIB_IRQCHIP */
1746 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
1747 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1751 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1754 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1757 * gpiochip_generic_request() - request the gpio function for a pin
1758 * @chip: the gpiochip owning the GPIO
1759 * @offset: the offset of the GPIO to request for GPIO function
1761 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
1763 return pinctrl_request_gpio(chip->gpiodev->base + offset);
1765 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1768 * gpiochip_generic_free() - free the gpio function from a pin
1769 * @chip: the gpiochip to request the gpio function for
1770 * @offset: the offset of the GPIO to free from GPIO function
1772 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
1774 pinctrl_free_gpio(chip->gpiodev->base + offset);
1776 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1778 #ifdef CONFIG_PINCTRL
1781 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1782 * @chip: the gpiochip to add the range for
1783 * @pctldev: the pin controller to map to
1784 * @gpio_offset: the start offset in the current gpio_chip number space
1785 * @pin_group: name of the pin group inside the pin controller
1787 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
1788 struct pinctrl_dev *pctldev,
1789 unsigned int gpio_offset, const char *pin_group)
1791 struct gpio_pin_range *pin_range;
1792 struct gpio_device *gdev = chip->gpiodev;
1795 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1797 chip_err(chip, "failed to allocate pin ranges\n");
1801 /* Use local offset as range ID */
1802 pin_range->range.id = gpio_offset;
1803 pin_range->range.gc = chip;
1804 pin_range->range.name = chip->label;
1805 pin_range->range.base = gdev->base + gpio_offset;
1806 pin_range->pctldev = pctldev;
1808 ret = pinctrl_get_group_pins(pctldev, pin_group,
1809 &pin_range->range.pins,
1810 &pin_range->range.npins);
1816 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1818 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1819 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1820 pinctrl_dev_get_devname(pctldev), pin_group);
1822 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1826 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1829 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1830 * @chip: the gpiochip to add the range for
1831 * @pinctrl_name: the dev_name() of the pin controller to map to
1832 * @gpio_offset: the start offset in the current gpio_chip number space
1833 * @pin_offset: the start offset in the pin controller number space
1834 * @npins: the number of pins from the offset of each pin space (GPIO and
1835 * pin controller) to accumulate in this range
1837 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
1838 unsigned int gpio_offset, unsigned int pin_offset,
1841 struct gpio_pin_range *pin_range;
1842 struct gpio_device *gdev = chip->gpiodev;
1845 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1847 chip_err(chip, "failed to allocate pin ranges\n");
1851 /* Use local offset as range ID */
1852 pin_range->range.id = gpio_offset;
1853 pin_range->range.gc = chip;
1854 pin_range->range.name = chip->label;
1855 pin_range->range.base = gdev->base + gpio_offset;
1856 pin_range->range.pin_base = pin_offset;
1857 pin_range->range.npins = npins;
1858 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1860 if (IS_ERR(pin_range->pctldev)) {
1861 ret = PTR_ERR(pin_range->pctldev);
1862 chip_err(chip, "could not create pin range\n");
1866 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1867 gpio_offset, gpio_offset + npins - 1,
1869 pin_offset, pin_offset + npins - 1);
1871 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1875 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1878 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1879 * @chip: the chip to remove all the mappings for
1881 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
1883 struct gpio_pin_range *pin_range, *tmp;
1884 struct gpio_device *gdev = chip->gpiodev;
1886 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1887 list_del(&pin_range->node);
1888 pinctrl_remove_gpio_range(pin_range->pctldev,
1893 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1895 #endif /* CONFIG_PINCTRL */
1897 /* These "optional" allocation calls help prevent drivers from stomping
1898 * on each other, and help provide better diagnostics in debugfs.
1899 * They're called even less than the "set direction" calls.
1901 static int __gpiod_request(struct gpio_desc *desc, const char *label)
1903 struct gpio_chip *chip = desc->gdev->chip;
1905 unsigned long flags;
1907 spin_lock_irqsave(&gpio_lock, flags);
1909 /* NOTE: gpio_request() can be called in early boot,
1910 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1913 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1914 desc_set_label(desc, label ? : "?");
1921 if (chip->request) {
1922 /* chip->request may sleep */
1923 spin_unlock_irqrestore(&gpio_lock, flags);
1924 status = chip->request(chip, gpio_chip_hwgpio(desc));
1925 spin_lock_irqsave(&gpio_lock, flags);
1928 desc_set_label(desc, NULL);
1929 clear_bit(FLAG_REQUESTED, &desc->flags);
1933 if (chip->get_direction) {
1934 /* chip->get_direction may sleep */
1935 spin_unlock_irqrestore(&gpio_lock, flags);
1936 gpiod_get_direction(desc);
1937 spin_lock_irqsave(&gpio_lock, flags);
1940 spin_unlock_irqrestore(&gpio_lock, flags);
1945 * This descriptor validation needs to be inserted verbatim into each
1946 * function taking a descriptor, so we need to use a preprocessor
1947 * macro to avoid endless duplication. If the desc is NULL it is an
1948 * optional GPIO and calls should just bail out.
1950 #define VALIDATE_DESC(desc) do { \
1953 if (IS_ERR(desc)) { \
1954 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
1955 return PTR_ERR(desc); \
1957 if (!desc->gdev) { \
1958 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
1961 if ( !desc->gdev->chip ) { \
1962 dev_warn(&desc->gdev->dev, \
1963 "%s: backing chip is gone\n", __func__); \
1967 #define VALIDATE_DESC_VOID(desc) do { \
1970 if (IS_ERR(desc)) { \
1971 pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
1974 if (!desc->gdev) { \
1975 pr_warn("%s: invalid GPIO (no device)\n", __func__); \
1978 if (!desc->gdev->chip) { \
1979 dev_warn(&desc->gdev->dev, \
1980 "%s: backing chip is gone\n", __func__); \
1985 int gpiod_request(struct gpio_desc *desc, const char *label)
1987 int status = -EPROBE_DEFER;
1988 struct gpio_device *gdev;
1990 VALIDATE_DESC(desc);
1993 if (try_module_get(gdev->owner)) {
1994 status = __gpiod_request(desc, label);
1996 module_put(gdev->owner);
1998 get_device(&gdev->dev);
2002 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2007 static bool __gpiod_free(struct gpio_desc *desc)
2010 unsigned long flags;
2011 struct gpio_chip *chip;
2015 gpiod_unexport(desc);
2017 spin_lock_irqsave(&gpio_lock, flags);
2019 chip = desc->gdev->chip;
2020 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2022 spin_unlock_irqrestore(&gpio_lock, flags);
2023 might_sleep_if(chip->can_sleep);
2024 chip->free(chip, gpio_chip_hwgpio(desc));
2025 spin_lock_irqsave(&gpio_lock, flags);
2027 desc_set_label(desc, NULL);
2028 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2029 clear_bit(FLAG_REQUESTED, &desc->flags);
2030 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2031 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2032 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2036 spin_unlock_irqrestore(&gpio_lock, flags);
2040 void gpiod_free(struct gpio_desc *desc)
2042 if (desc && desc->gdev && __gpiod_free(desc)) {
2043 module_put(desc->gdev->owner);
2044 put_device(&desc->gdev->dev);
2046 WARN_ON(extra_checks);
2051 * gpiochip_is_requested - return string iff signal was requested
2052 * @chip: controller managing the signal
2053 * @offset: of signal within controller's 0..(ngpio - 1) range
2055 * Returns NULL if the GPIO is not currently requested, else a string.
2056 * The string returned is the label passed to gpio_request(); if none has been
2057 * passed it is a meaningless, non-NULL constant.
2059 * This function is for use by GPIO controller drivers. The label can
2060 * help with diagnostics, and knowing that the signal is used as a GPIO
2061 * can help avoid accidentally multiplexing it to another controller.
2063 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2065 struct gpio_desc *desc;
2067 if (offset >= chip->ngpio)
2070 desc = &chip->gpiodev->descs[offset];
2072 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2076 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2079 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2080 * @desc: GPIO descriptor to request
2081 * @label: label for the GPIO
2083 * Function allows GPIO chip drivers to request and use their own GPIO
2084 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2085 * function will not increase reference count of the GPIO chip module. This
2086 * allows the GPIO chip module to be unloaded as needed (we assume that the
2087 * GPIO chip driver handles freeing the GPIOs it has requested).
2089 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2092 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2096 chip_err(chip, "failed to get GPIO descriptor\n");
2100 err = __gpiod_request(desc, label);
2102 return ERR_PTR(err);
2106 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2109 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2110 * @desc: GPIO descriptor to free
2112 * Function frees the given GPIO requested previously with
2113 * gpiochip_request_own_desc().
2115 void gpiochip_free_own_desc(struct gpio_desc *desc)
2120 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2123 * Drivers MUST set GPIO direction before making get/set calls. In
2124 * some cases this is done in early boot, before IRQs are enabled.
2126 * As a rule these aren't called more than once (except for drivers
2127 * using the open-drain emulation idiom) so these are natural places
2128 * to accumulate extra debugging checks. Note that we can't (yet)
2129 * rely on gpio_request() having been called beforehand.
2133 * gpiod_direction_input - set the GPIO direction to input
2134 * @desc: GPIO to set to input
2136 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2137 * be called safely on it.
2139 * Return 0 in case of success, else an error code.
2141 int gpiod_direction_input(struct gpio_desc *desc)
2143 struct gpio_chip *chip;
2144 int status = -EINVAL;
2146 VALIDATE_DESC(desc);
2147 chip = desc->gdev->chip;
2149 if (!chip->get || !chip->direction_input) {
2151 "%s: missing get() or direction_input() operations\n",
2156 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2158 clear_bit(FLAG_IS_OUT, &desc->flags);
2160 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2164 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2166 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2168 struct gpio_chip *gc = desc->gdev->chip;
2171 /* GPIOs used for IRQs shall not be set as output */
2172 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
2174 "%s: tried to set a GPIO tied to an IRQ as output\n",
2179 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2180 /* First see if we can enable open drain in hardware */
2181 if (gc->set_single_ended) {
2182 ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
2183 LINE_MODE_OPEN_DRAIN);
2185 goto set_output_value;
2187 /* Emulate open drain by not actively driving the line high */
2189 return gpiod_direction_input(desc);
2191 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2192 if (gc->set_single_ended) {
2193 ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
2194 LINE_MODE_OPEN_SOURCE);
2196 goto set_output_value;
2198 /* Emulate open source by not actively driving the line low */
2200 return gpiod_direction_input(desc);
2202 /* Make sure to disable open drain/source hardware, if any */
2203 if (gc->set_single_ended)
2204 gc->set_single_ended(gc,
2205 gpio_chip_hwgpio(desc),
2206 LINE_MODE_PUSH_PULL);
2210 if (!gc->set || !gc->direction_output) {
2212 "%s: missing set() or direction_output() operations\n",
2217 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), value);
2219 set_bit(FLAG_IS_OUT, &desc->flags);
2220 trace_gpio_value(desc_to_gpio(desc), 0, value);
2221 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2226 * gpiod_direction_output_raw - set the GPIO direction to output
2227 * @desc: GPIO to set to output
2228 * @value: initial output value of the GPIO
2230 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2231 * be called safely on it. The initial value of the output must be specified
2232 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2234 * Return 0 in case of success, else an error code.
2236 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2238 VALIDATE_DESC(desc);
2239 return _gpiod_direction_output_raw(desc, value);
2241 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2244 * gpiod_direction_output - set the GPIO direction to output
2245 * @desc: GPIO to set to output
2246 * @value: initial output value of the GPIO
2248 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2249 * be called safely on it. The initial value of the output must be specified
2250 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2253 * Return 0 in case of success, else an error code.
2255 int gpiod_direction_output(struct gpio_desc *desc, int value)
2257 VALIDATE_DESC(desc);
2258 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2260 return _gpiod_direction_output_raw(desc, value);
2262 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2265 * gpiod_set_debounce - sets @debounce time for a @gpio
2266 * @gpio: the gpio to set debounce time
2267 * @debounce: debounce time is microseconds
2269 * returns -ENOTSUPP if the controller does not support setting
2272 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2274 struct gpio_chip *chip;
2276 VALIDATE_DESC(desc);
2277 chip = desc->gdev->chip;
2278 if (!chip->set || !chip->set_debounce) {
2280 "%s: missing set() or set_debounce() operations\n",
2285 return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);
2287 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2290 * gpiod_is_active_low - test whether a GPIO is active-low or not
2291 * @desc: the gpio descriptor to test
2293 * Returns 1 if the GPIO is active-low, 0 otherwise.
2295 int gpiod_is_active_low(const struct gpio_desc *desc)
2297 VALIDATE_DESC(desc);
2298 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2300 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2302 /* I/O calls are only valid after configuration completed; the relevant
2303 * "is this a valid GPIO" error checks should already have been done.
2305 * "Get" operations are often inlinable as reading a pin value register,
2306 * and masking the relevant bit in that register.
2308 * When "set" operations are inlinable, they involve writing that mask to
2309 * one register to set a low value, or a different register to set it high.
2310 * Otherwise locking is needed, so there may be little value to inlining.
2312 *------------------------------------------------------------------------
2314 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2315 * have requested the GPIO. That can include implicit requesting by
2316 * a direction setting call. Marking a gpio as requested locks its chip
2317 * in memory, guaranteeing that these table lookups need no more locking
2318 * and that gpiochip_remove() will fail.
2320 * REVISIT when debugging, consider adding some instrumentation to ensure
2321 * that the GPIO was actually requested.
2324 static int _gpiod_get_raw_value(const struct gpio_desc *desc)
2326 struct gpio_chip *chip;
2330 chip = desc->gdev->chip;
2331 offset = gpio_chip_hwgpio(desc);
2332 value = chip->get ? chip->get(chip, offset) : -EIO;
2333 value = value < 0 ? value : !!value;
2334 trace_gpio_value(desc_to_gpio(desc), 1, value);
2339 * gpiod_get_raw_value() - return a gpio's raw value
2340 * @desc: gpio whose value will be returned
2342 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2343 * its ACTIVE_LOW status, or negative errno on failure.
2345 * This function should be called from contexts where we cannot sleep, and will
2346 * complain if the GPIO chip functions potentially sleep.
2348 int gpiod_get_raw_value(const struct gpio_desc *desc)
2350 VALIDATE_DESC(desc);
2351 /* Should be using gpio_get_value_cansleep() */
2352 WARN_ON(desc->gdev->chip->can_sleep);
2353 return _gpiod_get_raw_value(desc);
2355 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2358 * gpiod_get_value() - return a gpio's value
2359 * @desc: gpio whose value will be returned
2361 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2362 * account, or negative errno on failure.
2364 * This function should be called from contexts where we cannot sleep, and will
2365 * complain if the GPIO chip functions potentially sleep.
2367 int gpiod_get_value(const struct gpio_desc *desc)
2371 VALIDATE_DESC(desc);
2372 /* Should be using gpio_get_value_cansleep() */
2373 WARN_ON(desc->gdev->chip->can_sleep);
2375 value = _gpiod_get_raw_value(desc);
2379 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2384 EXPORT_SYMBOL_GPL(gpiod_get_value);
2387 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
2388 * @desc: gpio descriptor whose state need to be set.
2389 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2391 static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
2394 struct gpio_chip *chip = desc->gdev->chip;
2395 int offset = gpio_chip_hwgpio(desc);
2398 err = chip->direction_input(chip, offset);
2400 clear_bit(FLAG_IS_OUT, &desc->flags);
2402 err = chip->direction_output(chip, offset, 0);
2404 set_bit(FLAG_IS_OUT, &desc->flags);
2406 trace_gpio_direction(desc_to_gpio(desc), value, err);
2409 "%s: Error in set_value for open drain err %d\n",
2414 * _gpio_set_open_source_value() - Set the open source gpio's value.
2415 * @desc: gpio descriptor whose state need to be set.
2416 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2418 static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
2421 struct gpio_chip *chip = desc->gdev->chip;
2422 int offset = gpio_chip_hwgpio(desc);
2425 err = chip->direction_output(chip, offset, 1);
2427 set_bit(FLAG_IS_OUT, &desc->flags);
2429 err = chip->direction_input(chip, offset);
2431 clear_bit(FLAG_IS_OUT, &desc->flags);
2433 trace_gpio_direction(desc_to_gpio(desc), !value, err);
2436 "%s: Error in set_value for open source err %d\n",
2440 static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
2442 struct gpio_chip *chip;
2444 chip = desc->gdev->chip;
2445 trace_gpio_value(desc_to_gpio(desc), 0, value);
2446 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
2447 _gpio_set_open_drain_value(desc, value);
2448 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
2449 _gpio_set_open_source_value(desc, value);
2451 chip->set(chip, gpio_chip_hwgpio(desc), value);
2455 * set multiple outputs on the same chip;
2456 * use the chip's set_multiple function if available;
2457 * otherwise set the outputs sequentially;
2458 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2459 * defines which outputs are to be changed
2460 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2461 * defines the values the outputs specified by mask are to be set to
2463 static void gpio_chip_set_multiple(struct gpio_chip *chip,
2464 unsigned long *mask, unsigned long *bits)
2466 if (chip->set_multiple) {
2467 chip->set_multiple(chip, mask, bits);
2470 for (i = 0; i < chip->ngpio; i++) {
2471 if (mask[BIT_WORD(i)] == 0) {
2472 /* no more set bits in this mask word;
2473 * skip ahead to the next word */
2474 i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1;
2477 /* set outputs if the corresponding mask bit is set */
2478 if (__test_and_clear_bit(i, mask))
2479 chip->set(chip, i, test_bit(i, bits));
2484 void gpiod_set_array_value_complex(bool raw, bool can_sleep,
2485 unsigned int array_size,
2486 struct gpio_desc **desc_array,
2491 while (i < array_size) {
2492 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2493 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
2494 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
2498 WARN_ON(chip->can_sleep);
2500 memset(mask, 0, sizeof(mask));
2502 struct gpio_desc *desc = desc_array[i];
2503 int hwgpio = gpio_chip_hwgpio(desc);
2504 int value = value_array[i];
2506 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2508 trace_gpio_value(desc_to_gpio(desc), 0, value);
2510 * collect all normal outputs belonging to the same chip
2511 * open drain and open source outputs are set individually
2513 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2514 _gpio_set_open_drain_value(desc, value);
2515 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2516 _gpio_set_open_source_value(desc, value);
2518 __set_bit(hwgpio, mask);
2520 __set_bit(hwgpio, bits);
2522 __clear_bit(hwgpio, bits);
2526 } while ((i < array_size) &&
2527 (desc_array[i]->gdev->chip == chip));
2528 /* push collected bits to outputs */
2530 gpio_chip_set_multiple(chip, mask, bits);
2535 * gpiod_set_raw_value() - assign a gpio's raw value
2536 * @desc: gpio whose value will be assigned
2537 * @value: value to assign
2539 * Set the raw value of the GPIO, i.e. the value of its physical line without
2540 * regard for its ACTIVE_LOW status.
2542 * This function should be called from contexts where we cannot sleep, and will
2543 * complain if the GPIO chip functions potentially sleep.
2545 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
2547 VALIDATE_DESC_VOID(desc);
2548 /* Should be using gpiod_set_value_cansleep() */
2549 WARN_ON(desc->gdev->chip->can_sleep);
2550 _gpiod_set_raw_value(desc, value);
2552 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
2555 * gpiod_set_value() - assign a gpio's value
2556 * @desc: gpio whose value will be assigned
2557 * @value: value to assign
2559 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2562 * This function should be called from contexts where we cannot sleep, and will
2563 * complain if the GPIO chip functions potentially sleep.
2565 void gpiod_set_value(struct gpio_desc *desc, int value)
2567 VALIDATE_DESC_VOID(desc);
2568 /* Should be using gpiod_set_value_cansleep() */
2569 WARN_ON(desc->gdev->chip->can_sleep);
2570 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2572 _gpiod_set_raw_value(desc, value);
2574 EXPORT_SYMBOL_GPL(gpiod_set_value);
2577 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
2578 * @array_size: number of elements in the descriptor / value arrays
2579 * @desc_array: array of GPIO descriptors whose values will be assigned
2580 * @value_array: array of values to assign
2582 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2583 * without regard for their ACTIVE_LOW status.
2585 * This function should be called from contexts where we cannot sleep, and will
2586 * complain if the GPIO chip functions potentially sleep.
2588 void gpiod_set_raw_array_value(unsigned int array_size,
2589 struct gpio_desc **desc_array, int *value_array)
2593 gpiod_set_array_value_complex(true, false, array_size, desc_array,
2596 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
2599 * gpiod_set_array_value() - assign values to an array of GPIOs
2600 * @array_size: number of elements in the descriptor / value arrays
2601 * @desc_array: array of GPIO descriptors whose values will be assigned
2602 * @value_array: array of values to assign
2604 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2607 * This function should be called from contexts where we cannot sleep, and will
2608 * complain if the GPIO chip functions potentially sleep.
2610 void gpiod_set_array_value(unsigned int array_size,
2611 struct gpio_desc **desc_array, int *value_array)
2615 gpiod_set_array_value_complex(false, false, array_size, desc_array,
2618 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
2621 * gpiod_cansleep() - report whether gpio value access may sleep
2622 * @desc: gpio to check
2625 int gpiod_cansleep(const struct gpio_desc *desc)
2627 VALIDATE_DESC(desc);
2628 return desc->gdev->chip->can_sleep;
2630 EXPORT_SYMBOL_GPL(gpiod_cansleep);
2633 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
2634 * @desc: gpio whose IRQ will be returned (already requested)
2636 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
2639 int gpiod_to_irq(const struct gpio_desc *desc)
2641 struct gpio_chip *chip;
2645 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
2646 * requires this function to not return zero on an invalid descriptor
2647 * but rather a negative error number.
2649 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
2652 chip = desc->gdev->chip;
2653 offset = gpio_chip_hwgpio(desc);
2655 int retirq = chip->to_irq(chip, offset);
2657 /* Zero means NO_IRQ */
2665 EXPORT_SYMBOL_GPL(gpiod_to_irq);
2668 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
2669 * @chip: the chip the GPIO to lock belongs to
2670 * @offset: the offset of the GPIO to lock as IRQ
2672 * This is used directly by GPIO drivers that want to lock down
2673 * a certain GPIO line to be used for IRQs.
2675 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
2677 struct gpio_desc *desc;
2679 desc = gpiochip_get_desc(chip, offset);
2681 return PTR_ERR(desc);
2683 /* Flush direction if something changed behind our back */
2684 if (chip->get_direction) {
2685 int dir = chip->get_direction(chip, offset);
2688 clear_bit(FLAG_IS_OUT, &desc->flags);
2690 set_bit(FLAG_IS_OUT, &desc->flags);
2693 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
2695 "%s: tried to flag a GPIO set as output for IRQ\n",
2700 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
2703 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
2706 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
2707 * @chip: the chip the GPIO to lock belongs to
2708 * @offset: the offset of the GPIO to lock as IRQ
2710 * This is used directly by GPIO drivers that want to indicate
2711 * that a certain GPIO is no longer used exclusively for IRQ.
2713 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
2715 if (offset >= chip->ngpio)
2718 clear_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2720 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
2722 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
2724 if (offset >= chip->ngpio)
2727 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2729 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
2731 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
2733 if (offset >= chip->ngpio)
2736 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
2738 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
2740 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
2742 if (offset >= chip->ngpio)
2745 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
2747 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
2750 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2751 * @desc: gpio whose value will be returned
2753 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2754 * its ACTIVE_LOW status, or negative errno on failure.
2756 * This function is to be called from contexts that can sleep.
2758 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
2760 might_sleep_if(extra_checks);
2761 VALIDATE_DESC(desc);
2762 return _gpiod_get_raw_value(desc);
2764 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
2767 * gpiod_get_value_cansleep() - return a gpio's value
2768 * @desc: gpio whose value will be returned
2770 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2771 * account, or negative errno on failure.
2773 * This function is to be called from contexts that can sleep.
2775 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
2779 might_sleep_if(extra_checks);
2780 VALIDATE_DESC(desc);
2781 value = _gpiod_get_raw_value(desc);
2785 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2790 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
2793 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2794 * @desc: gpio whose value will be assigned
2795 * @value: value to assign
2797 * Set the raw value of the GPIO, i.e. the value of its physical line without
2798 * regard for its ACTIVE_LOW status.
2800 * This function is to be called from contexts that can sleep.
2802 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
2804 might_sleep_if(extra_checks);
2805 VALIDATE_DESC_VOID(desc);
2806 _gpiod_set_raw_value(desc, value);
2808 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
2811 * gpiod_set_value_cansleep() - assign a gpio's value
2812 * @desc: gpio whose value will be assigned
2813 * @value: value to assign
2815 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2818 * This function is to be called from contexts that can sleep.
2820 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
2822 might_sleep_if(extra_checks);
2823 VALIDATE_DESC_VOID(desc);
2824 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2826 _gpiod_set_raw_value(desc, value);
2828 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
2831 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2832 * @array_size: number of elements in the descriptor / value arrays
2833 * @desc_array: array of GPIO descriptors whose values will be assigned
2834 * @value_array: array of values to assign
2836 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2837 * without regard for their ACTIVE_LOW status.
2839 * This function is to be called from contexts that can sleep.
2841 void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
2842 struct gpio_desc **desc_array,
2845 might_sleep_if(extra_checks);
2848 gpiod_set_array_value_complex(true, true, array_size, desc_array,
2851 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
2854 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2855 * @array_size: number of elements in the descriptor / value arrays
2856 * @desc_array: array of GPIO descriptors whose values will be assigned
2857 * @value_array: array of values to assign
2859 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2862 * This function is to be called from contexts that can sleep.
2864 void gpiod_set_array_value_cansleep(unsigned int array_size,
2865 struct gpio_desc **desc_array,
2868 might_sleep_if(extra_checks);
2871 gpiod_set_array_value_complex(false, true, array_size, desc_array,
2874 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
2877 * gpiod_add_lookup_table() - register GPIO device consumers
2878 * @table: table of consumers to register
2880 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
2882 mutex_lock(&gpio_lookup_lock);
2884 list_add_tail(&table->list, &gpio_lookup_list);
2886 mutex_unlock(&gpio_lookup_lock);
2890 * gpiod_remove_lookup_table() - unregister GPIO device consumers
2891 * @table: table of consumers to unregister
2893 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
2895 mutex_lock(&gpio_lookup_lock);
2897 list_del(&table->list);
2899 mutex_unlock(&gpio_lookup_lock);
2902 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
2904 const char *dev_id = dev ? dev_name(dev) : NULL;
2905 struct gpiod_lookup_table *table;
2907 mutex_lock(&gpio_lookup_lock);
2909 list_for_each_entry(table, &gpio_lookup_list, list) {
2910 if (table->dev_id && dev_id) {
2912 * Valid strings on both ends, must be identical to have
2915 if (!strcmp(table->dev_id, dev_id))
2919 * One of the pointers is NULL, so both must be to have
2922 if (dev_id == table->dev_id)
2929 mutex_unlock(&gpio_lookup_lock);
2933 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
2935 enum gpio_lookup_flags *flags)
2937 struct gpio_desc *desc = ERR_PTR(-ENOENT);
2938 struct gpiod_lookup_table *table;
2939 struct gpiod_lookup *p;
2941 table = gpiod_find_lookup_table(dev);
2945 for (p = &table->table[0]; p->chip_label; p++) {
2946 struct gpio_chip *chip;
2948 /* idx must always match exactly */
2952 /* If the lookup entry has a con_id, require exact match */
2953 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
2956 chip = find_chip_by_name(p->chip_label);
2959 dev_err(dev, "cannot find GPIO chip %s\n",
2961 return ERR_PTR(-ENODEV);
2964 if (chip->ngpio <= p->chip_hwnum) {
2966 "requested GPIO %d is out of range [0..%d] for chip %s\n",
2967 idx, chip->ngpio, chip->label);
2968 return ERR_PTR(-EINVAL);
2971 desc = gpiochip_get_desc(chip, p->chip_hwnum);
2980 static int dt_gpio_count(struct device *dev, const char *con_id)
2986 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
2988 snprintf(propname, sizeof(propname), "%s-%s",
2989 con_id, gpio_suffixes[i]);
2991 snprintf(propname, sizeof(propname), "%s",
2994 ret = of_gpio_named_count(dev->of_node, propname);
3001 static int platform_gpio_count(struct device *dev, const char *con_id)
3003 struct gpiod_lookup_table *table;
3004 struct gpiod_lookup *p;
3005 unsigned int count = 0;
3007 table = gpiod_find_lookup_table(dev);
3011 for (p = &table->table[0]; p->chip_label; p++) {
3012 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3013 (!con_id && !p->con_id))
3023 * gpiod_count - return the number of GPIOs associated with a device / function
3024 * or -ENOENT if no GPIO has been assigned to the requested function
3025 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3026 * @con_id: function within the GPIO consumer
3028 int gpiod_count(struct device *dev, const char *con_id)
3030 int count = -ENOENT;
3032 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
3033 count = dt_gpio_count(dev, con_id);
3034 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
3035 count = acpi_gpio_count(dev, con_id);
3038 count = platform_gpio_count(dev, con_id);
3042 EXPORT_SYMBOL_GPL(gpiod_count);
3045 * gpiod_get - obtain a GPIO for a given GPIO function
3046 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3047 * @con_id: function within the GPIO consumer
3048 * @flags: optional GPIO initialization flags
3050 * Return the GPIO descriptor corresponding to the function con_id of device
3051 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3052 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3054 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3055 enum gpiod_flags flags)
3057 return gpiod_get_index(dev, con_id, 0, flags);
3059 EXPORT_SYMBOL_GPL(gpiod_get);
3062 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3063 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3064 * @con_id: function within the GPIO consumer
3065 * @flags: optional GPIO initialization flags
3067 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3068 * the requested function it will return NULL. This is convenient for drivers
3069 * that need to handle optional GPIOs.
3071 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3073 enum gpiod_flags flags)
3075 return gpiod_get_index_optional(dev, con_id, 0, flags);
3077 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3081 * gpiod_configure_flags - helper function to configure a given GPIO
3082 * @desc: gpio whose value will be assigned
3083 * @con_id: function within the GPIO consumer
3084 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3086 * @dflags: gpiod_flags - optional GPIO initialization flags
3088 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3089 * requested function and/or index, or another IS_ERR() code if an error
3090 * occurred while trying to acquire the GPIO.
3092 static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3093 unsigned long lflags, enum gpiod_flags dflags)
3097 if (lflags & GPIO_ACTIVE_LOW)
3098 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3099 if (lflags & GPIO_OPEN_DRAIN)
3100 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3101 if (lflags & GPIO_OPEN_SOURCE)
3102 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3104 /* No particular flag request, return here... */
3105 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3106 pr_debug("no flags found for %s\n", con_id);
3111 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3112 status = gpiod_direction_output(desc,
3113 dflags & GPIOD_FLAGS_BIT_DIR_VAL);
3115 status = gpiod_direction_input(desc);
3121 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3122 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3123 * @con_id: function within the GPIO consumer
3124 * @idx: index of the GPIO to obtain in the consumer
3125 * @flags: optional GPIO initialization flags
3127 * This variant of gpiod_get() allows to access GPIOs other than the first
3128 * defined one for functions that define several GPIOs.
3130 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3131 * requested function and/or index, or another IS_ERR() code if an error
3132 * occurred while trying to acquire the GPIO.
3134 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3137 enum gpiod_flags flags)
3139 struct gpio_desc *desc = NULL;
3141 enum gpio_lookup_flags lookupflags = 0;
3143 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3146 /* Using device tree? */
3147 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
3148 dev_dbg(dev, "using device tree for GPIO lookup\n");
3149 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3150 } else if (ACPI_COMPANION(dev)) {
3151 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3152 desc = acpi_find_gpio(dev, con_id, idx, flags, &lookupflags);
3157 * Either we are not using DT or ACPI, or their lookup did not return
3158 * a result. In that case, use platform lookup as a fallback.
3160 if (!desc || desc == ERR_PTR(-ENOENT)) {
3161 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3162 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3166 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
3170 status = gpiod_request(desc, con_id);
3172 return ERR_PTR(status);
3174 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3176 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3178 return ERR_PTR(status);
3183 EXPORT_SYMBOL_GPL(gpiod_get_index);
3186 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3187 * @fwnode: handle of the firmware node
3188 * @propname: name of the firmware property representing the GPIO
3190 * This function can be used for drivers that get their configuration
3193 * Function properly finds the corresponding GPIO using whatever is the
3194 * underlying firmware interface and then makes sure that the GPIO
3195 * descriptor is requested before it is returned to the caller.
3197 * In case of error an ERR_PTR() is returned.
3199 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
3200 const char *propname)
3202 struct gpio_desc *desc = ERR_PTR(-ENODEV);
3203 bool active_low = false;
3204 bool single_ended = false;
3208 return ERR_PTR(-EINVAL);
3210 if (is_of_node(fwnode)) {
3211 enum of_gpio_flags flags;
3213 desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0,
3215 if (!IS_ERR(desc)) {
3216 active_low = flags & OF_GPIO_ACTIVE_LOW;
3217 single_ended = flags & OF_GPIO_SINGLE_ENDED;
3219 } else if (is_acpi_node(fwnode)) {
3220 struct acpi_gpio_info info;
3222 desc = acpi_node_get_gpiod(fwnode, propname, 0, &info);
3224 active_low = info.polarity == GPIO_ACTIVE_LOW;
3230 ret = gpiod_request(desc, NULL);
3232 return ERR_PTR(ret);
3235 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3239 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3241 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3246 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
3249 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
3251 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3252 * @con_id: function within the GPIO consumer
3253 * @index: index of the GPIO to obtain in the consumer
3254 * @flags: optional GPIO initialization flags
3256 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
3257 * specified index was assigned to the requested function it will return NULL.
3258 * This is convenient for drivers that need to handle optional GPIOs.
3260 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
3263 enum gpiod_flags flags)
3265 struct gpio_desc *desc;
3267 desc = gpiod_get_index(dev, con_id, index, flags);
3269 if (PTR_ERR(desc) == -ENOENT)
3275 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
3278 * gpiod_hog - Hog the specified GPIO desc given the provided flags
3279 * @desc: gpio whose value will be assigned
3280 * @name: gpio line name
3281 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3283 * @dflags: gpiod_flags - optional GPIO initialization flags
3285 int gpiod_hog(struct gpio_desc *desc, const char *name,
3286 unsigned long lflags, enum gpiod_flags dflags)
3288 struct gpio_chip *chip;
3289 struct gpio_desc *local_desc;
3293 chip = gpiod_to_chip(desc);
3294 hwnum = gpio_chip_hwgpio(desc);
3296 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
3297 if (IS_ERR(local_desc)) {
3298 status = PTR_ERR(local_desc);
3299 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
3300 name, chip->label, hwnum, status);
3304 status = gpiod_configure_flags(desc, name, lflags, dflags);
3306 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
3307 name, chip->label, hwnum, status);
3308 gpiochip_free_own_desc(desc);
3312 /* Mark GPIO as hogged so it can be identified and removed later */
3313 set_bit(FLAG_IS_HOGGED, &desc->flags);
3315 pr_info("GPIO line %d (%s) hogged as %s%s\n",
3316 desc_to_gpio(desc), name,
3317 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
3318 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
3319 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
3325 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
3326 * @chip: gpio chip to act on
3328 * This is only used by of_gpiochip_remove to free hogged gpios
3330 static void gpiochip_free_hogs(struct gpio_chip *chip)
3334 for (id = 0; id < chip->ngpio; id++) {
3335 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
3336 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
3341 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
3342 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3343 * @con_id: function within the GPIO consumer
3344 * @flags: optional GPIO initialization flags
3346 * This function acquires all the GPIOs defined under a given function.
3348 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
3349 * no GPIO has been assigned to the requested function, or another IS_ERR()
3350 * code if an error occurred while trying to acquire the GPIOs.
3352 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
3354 enum gpiod_flags flags)
3356 struct gpio_desc *desc;
3357 struct gpio_descs *descs;
3360 count = gpiod_count(dev, con_id);
3362 return ERR_PTR(count);
3364 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
3367 return ERR_PTR(-ENOMEM);
3369 for (descs->ndescs = 0; descs->ndescs < count; ) {
3370 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
3372 gpiod_put_array(descs);
3373 return ERR_CAST(desc);
3375 descs->desc[descs->ndescs] = desc;
3380 EXPORT_SYMBOL_GPL(gpiod_get_array);
3383 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
3385 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3386 * @con_id: function within the GPIO consumer
3387 * @flags: optional GPIO initialization flags
3389 * This is equivalent to gpiod_get_array(), except that when no GPIO was
3390 * assigned to the requested function it will return NULL.
3392 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
3394 enum gpiod_flags flags)
3396 struct gpio_descs *descs;
3398 descs = gpiod_get_array(dev, con_id, flags);
3399 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
3404 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
3407 * gpiod_put - dispose of a GPIO descriptor
3408 * @desc: GPIO descriptor to dispose of
3410 * No descriptor can be used after gpiod_put() has been called on it.
3412 void gpiod_put(struct gpio_desc *desc)
3416 EXPORT_SYMBOL_GPL(gpiod_put);
3419 * gpiod_put_array - dispose of multiple GPIO descriptors
3420 * @descs: struct gpio_descs containing an array of descriptors
3422 void gpiod_put_array(struct gpio_descs *descs)
3426 for (i = 0; i < descs->ndescs; i++)
3427 gpiod_put(descs->desc[i]);
3431 EXPORT_SYMBOL_GPL(gpiod_put_array);
3433 static int __init gpiolib_dev_init(void)
3437 /* Register GPIO sysfs bus */
3438 ret = bus_register(&gpio_bus_type);
3440 pr_err("gpiolib: could not register GPIO bus type\n");
3444 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
3446 pr_err("gpiolib: failed to allocate char dev region\n");
3447 bus_unregister(&gpio_bus_type);
3449 gpiolib_initialized = true;
3450 gpiochip_setup_devs();
3454 core_initcall(gpiolib_dev_init);
3456 #ifdef CONFIG_DEBUG_FS
3458 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
3461 struct gpio_chip *chip = gdev->chip;
3462 unsigned gpio = gdev->base;
3463 struct gpio_desc *gdesc = &gdev->descs[0];
3467 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
3468 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
3470 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
3476 gpiod_get_direction(gdesc);
3477 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
3478 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
3479 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
3480 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
3481 is_out ? "out" : "in ",
3483 ? (chip->get(chip, i) ? "hi" : "lo")
3485 is_irq ? "IRQ" : " ");
3486 seq_printf(s, "\n");
3490 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
3492 unsigned long flags;
3493 struct gpio_device *gdev = NULL;
3494 loff_t index = *pos;
3498 spin_lock_irqsave(&gpio_lock, flags);
3499 list_for_each_entry(gdev, &gpio_devices, list)
3501 spin_unlock_irqrestore(&gpio_lock, flags);
3504 spin_unlock_irqrestore(&gpio_lock, flags);
3509 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
3511 unsigned long flags;
3512 struct gpio_device *gdev = v;
3515 spin_lock_irqsave(&gpio_lock, flags);
3516 if (list_is_last(&gdev->list, &gpio_devices))
3519 ret = list_entry(gdev->list.next, struct gpio_device, list);
3520 spin_unlock_irqrestore(&gpio_lock, flags);
3528 static void gpiolib_seq_stop(struct seq_file *s, void *v)
3532 static int gpiolib_seq_show(struct seq_file *s, void *v)
3534 struct gpio_device *gdev = v;
3535 struct gpio_chip *chip = gdev->chip;
3536 struct device *parent;
3539 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
3540 dev_name(&gdev->dev));
3544 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
3545 dev_name(&gdev->dev),
3546 gdev->base, gdev->base + gdev->ngpio - 1);
3547 parent = chip->parent;
3549 seq_printf(s, ", parent: %s/%s",
3550 parent->bus ? parent->bus->name : "no-bus",
3553 seq_printf(s, ", %s", chip->label);
3554 if (chip->can_sleep)
3555 seq_printf(s, ", can sleep");
3556 seq_printf(s, ":\n");
3559 chip->dbg_show(s, chip);
3561 gpiolib_dbg_show(s, gdev);
3566 static const struct seq_operations gpiolib_seq_ops = {
3567 .start = gpiolib_seq_start,
3568 .next = gpiolib_seq_next,
3569 .stop = gpiolib_seq_stop,
3570 .show = gpiolib_seq_show,
3573 static int gpiolib_open(struct inode *inode, struct file *file)
3575 return seq_open(file, &gpiolib_seq_ops);
3578 static const struct file_operations gpiolib_operations = {
3579 .owner = THIS_MODULE,
3580 .open = gpiolib_open,
3582 .llseek = seq_lseek,
3583 .release = seq_release,
3586 static int __init gpiolib_debugfs_init(void)
3588 /* /sys/kernel/debug/gpio */
3589 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
3590 NULL, NULL, &gpiolib_operations);
3593 subsys_initcall(gpiolib_debugfs_init);
3595 #endif /* DEBUG_FS */