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/idr.h>
20 #include <linux/cdev.h>
22 #include <linux/uaccess.h>
23 #include <uapi/linux/gpio.h>
27 #define CREATE_TRACE_POINTS
28 #include <trace/events/gpio.h>
30 /* Implementation infrastructure for GPIO interfaces.
32 * The GPIO programming interface allows for inlining speed-critical
33 * get/set operations for common cases, so that access to SOC-integrated
34 * GPIOs can sometimes cost only an instruction or two per bit.
38 /* When debugging, extend minimal trust to callers and platform code.
39 * Also emit diagnostic messages that may help initial bringup, when
40 * board setup or driver bugs are most common.
42 * Otherwise, minimize overhead in what may be bitbanging codepaths.
45 #define extra_checks 1
47 #define extra_checks 0
50 /* Device and char device-related information */
51 static DEFINE_IDA(gpio_ida
);
52 static dev_t gpio_devt
;
53 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
54 static struct bus_type gpio_bus_type
= {
58 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
59 * While any GPIO is requested, its gpio_chip is not removable;
60 * each GPIO's "requested" flag serves as a lock and refcount.
62 DEFINE_SPINLOCK(gpio_lock
);
64 static DEFINE_MUTEX(gpio_lookup_lock
);
65 static LIST_HEAD(gpio_lookup_list
);
66 LIST_HEAD(gpio_devices
);
68 static void gpiochip_free_hogs(struct gpio_chip
*chip
);
69 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
);
72 static inline void desc_set_label(struct gpio_desc
*d
, const char *label
)
78 * Convert a GPIO number to its descriptor
80 struct gpio_desc
*gpio_to_desc(unsigned gpio
)
82 struct gpio_device
*gdev
;
85 spin_lock_irqsave(&gpio_lock
, flags
);
87 list_for_each_entry(gdev
, &gpio_devices
, list
) {
88 if (gdev
->base
<= gpio
&&
89 gdev
->base
+ gdev
->ngpio
> gpio
) {
90 spin_unlock_irqrestore(&gpio_lock
, flags
);
91 return &gdev
->descs
[gpio
- gdev
->base
];
95 spin_unlock_irqrestore(&gpio_lock
, flags
);
97 if (!gpio_is_valid(gpio
))
98 WARN(1, "invalid GPIO %d\n", gpio
);
102 EXPORT_SYMBOL_GPL(gpio_to_desc
);
105 * Get the GPIO descriptor corresponding to the given hw number for this chip.
107 struct gpio_desc
*gpiochip_get_desc(struct gpio_chip
*chip
,
110 struct gpio_device
*gdev
= chip
->gpiodev
;
112 if (hwnum
>= gdev
->ngpio
)
113 return ERR_PTR(-EINVAL
);
115 return &gdev
->descs
[hwnum
];
119 * Convert a GPIO descriptor to the integer namespace.
120 * This should disappear in the future but is needed since we still
121 * use GPIO numbers for error messages and sysfs nodes
123 int desc_to_gpio(const struct gpio_desc
*desc
)
125 return desc
->gdev
->base
+ (desc
- &desc
->gdev
->descs
[0]);
127 EXPORT_SYMBOL_GPL(desc_to_gpio
);
131 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
132 * @desc: descriptor to return the chip of
134 struct gpio_chip
*gpiod_to_chip(const struct gpio_desc
*desc
)
136 if (!desc
|| !desc
->gdev
|| !desc
->gdev
->chip
)
138 return desc
->gdev
->chip
;
140 EXPORT_SYMBOL_GPL(gpiod_to_chip
);
142 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
143 static int gpiochip_find_base(int ngpio
)
145 struct gpio_device
*gdev
;
146 int base
= ARCH_NR_GPIOS
- ngpio
;
148 list_for_each_entry_reverse(gdev
, &gpio_devices
, list
) {
149 /* found a free space? */
150 if (gdev
->base
+ gdev
->ngpio
<= base
)
153 /* nope, check the space right before the chip */
154 base
= gdev
->base
- ngpio
;
157 if (gpio_is_valid(base
)) {
158 pr_debug("%s: found new base at %d\n", __func__
, base
);
161 pr_err("%s: cannot find free range\n", __func__
);
167 * gpiod_get_direction - return the current direction of a GPIO
168 * @desc: GPIO to get the direction of
170 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
172 * This function may sleep if gpiod_cansleep() is true.
174 int gpiod_get_direction(struct gpio_desc
*desc
)
176 struct gpio_chip
*chip
;
178 int status
= -EINVAL
;
180 chip
= gpiod_to_chip(desc
);
181 offset
= gpio_chip_hwgpio(desc
);
183 if (!chip
->get_direction
)
186 status
= chip
->get_direction(chip
, offset
);
188 /* GPIOF_DIR_IN, or other positive */
190 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
194 set_bit(FLAG_IS_OUT
, &desc
->flags
);
198 EXPORT_SYMBOL_GPL(gpiod_get_direction
);
201 * Add a new chip to the global chips list, keeping the list of chips sorted
202 * by range(means [base, base + ngpio - 1]) order.
204 * Return -EBUSY if the new chip overlaps with some other chip's integer
207 static int gpiodev_add_to_list(struct gpio_device
*gdev
)
209 struct gpio_device
*iterator
;
210 struct gpio_device
*previous
= NULL
;
215 if (list_empty(&gpio_devices
)) {
216 list_add_tail(&gdev
->list
, &gpio_devices
);
220 list_for_each_entry(iterator
, &gpio_devices
, list
) {
221 if (iterator
->base
>= gdev
->base
+ gdev
->ngpio
) {
223 * Iterator is the first GPIO chip so there is no
230 * We found a valid range(means
231 * [base, base + ngpio - 1]) between previous
234 if (previous
->base
+ previous
->ngpio
243 * We are beyond the last chip in the list and iterator now
244 * points to the head.
245 * Let iterator point to the last chip in the list.
248 iterator
= list_last_entry(&gpio_devices
, struct gpio_device
, list
);
249 if (iterator
->base
+ iterator
->ngpio
<= gdev
->base
) {
250 list_add(&gdev
->list
, &iterator
->list
);
255 "GPIO integer space overlap, cannot add chip\n");
259 list_add_tail(&gdev
->list
, &iterator
->list
);
264 * Convert a GPIO name to its descriptor
266 static struct gpio_desc
*gpio_name_to_desc(const char * const name
)
268 struct gpio_device
*gdev
;
271 spin_lock_irqsave(&gpio_lock
, flags
);
273 list_for_each_entry(gdev
, &gpio_devices
, list
) {
276 for (i
= 0; i
!= gdev
->ngpio
; ++i
) {
277 struct gpio_desc
*desc
= &gdev
->descs
[i
];
279 if (!desc
->name
|| !name
)
282 if (!strcmp(desc
->name
, name
)) {
283 spin_unlock_irqrestore(&gpio_lock
, flags
);
289 spin_unlock_irqrestore(&gpio_lock
, flags
);
295 * Takes the names from gc->names and checks if they are all unique. If they
296 * are, they are assigned to their gpio descriptors.
298 * Warning if one of the names is already used for a different GPIO.
300 static int gpiochip_set_desc_names(struct gpio_chip
*gc
)
302 struct gpio_device
*gdev
= gc
->gpiodev
;
308 /* First check all names if they are unique */
309 for (i
= 0; i
!= gc
->ngpio
; ++i
) {
310 struct gpio_desc
*gpio
;
312 gpio
= gpio_name_to_desc(gc
->names
[i
]);
315 "Detected name collision for GPIO name '%s'\n",
319 /* Then add all names to the GPIO descriptors */
320 for (i
= 0; i
!= gc
->ngpio
; ++i
)
321 gdev
->descs
[i
].name
= gc
->names
[i
];
327 * gpio_ioctl() - ioctl handler for the GPIO chardev
329 static long gpio_ioctl(struct file
*filp
, unsigned int cmd
, unsigned long arg
)
331 struct gpio_device
*gdev
= filp
->private_data
;
332 struct gpio_chip
*chip
= gdev
->chip
;
333 int __user
*ip
= (int __user
*)arg
;
335 /* We fail any subsequent ioctl():s when the chip is gone */
339 /* Fill in the struct and pass to userspace */
340 if (cmd
== GPIO_GET_CHIPINFO_IOCTL
) {
341 struct gpiochip_info chipinfo
;
343 strncpy(chipinfo
.name
, dev_name(&gdev
->dev
),
344 sizeof(chipinfo
.name
));
345 chipinfo
.name
[sizeof(chipinfo
.name
)-1] = '\0';
346 strncpy(chipinfo
.label
, gdev
->label
,
347 sizeof(chipinfo
.label
));
348 chipinfo
.label
[sizeof(chipinfo
.label
)-1] = '\0';
349 chipinfo
.lines
= gdev
->ngpio
;
350 if (copy_to_user(ip
, &chipinfo
, sizeof(chipinfo
)))
353 } else if (cmd
== GPIO_GET_LINEINFO_IOCTL
) {
354 struct gpioline_info lineinfo
;
355 struct gpio_desc
*desc
;
357 if (copy_from_user(&lineinfo
, ip
, sizeof(lineinfo
)))
359 if (lineinfo
.line_offset
> gdev
->ngpio
)
362 desc
= &gdev
->descs
[lineinfo
.line_offset
];
364 strncpy(lineinfo
.name
, desc
->name
,
365 sizeof(lineinfo
.name
));
366 lineinfo
.name
[sizeof(lineinfo
.name
)-1] = '\0';
368 lineinfo
.name
[0] = '\0';
371 strncpy(lineinfo
.label
, desc
->label
,
372 sizeof(lineinfo
.label
));
373 lineinfo
.label
[sizeof(lineinfo
.label
)-1] = '\0';
375 lineinfo
.label
[0] = '\0';
379 * Userspace only need to know that the kernel is using
380 * this GPIO so it can't use it.
383 if (test_bit(FLAG_REQUESTED
, &desc
->flags
) ||
384 test_bit(FLAG_IS_HOGGED
, &desc
->flags
) ||
385 test_bit(FLAG_USED_AS_IRQ
, &desc
->flags
) ||
386 test_bit(FLAG_EXPORT
, &desc
->flags
) ||
387 test_bit(FLAG_SYSFS
, &desc
->flags
))
388 lineinfo
.flags
|= GPIOLINE_FLAG_KERNEL
;
389 if (test_bit(FLAG_IS_OUT
, &desc
->flags
))
390 lineinfo
.flags
|= GPIOLINE_FLAG_IS_OUT
;
391 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
392 lineinfo
.flags
|= GPIOLINE_FLAG_ACTIVE_LOW
;
393 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
))
394 lineinfo
.flags
|= GPIOLINE_FLAG_OPEN_DRAIN
;
395 if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
))
396 lineinfo
.flags
|= GPIOLINE_FLAG_OPEN_SOURCE
;
398 if (copy_to_user(ip
, &lineinfo
, sizeof(lineinfo
)))
406 * gpio_chrdev_open() - open the chardev for ioctl operations
407 * @inode: inode for this chardev
408 * @filp: file struct for storing private data
409 * Returns 0 on success
411 static int gpio_chrdev_open(struct inode
*inode
, struct file
*filp
)
413 struct gpio_device
*gdev
= container_of(inode
->i_cdev
,
414 struct gpio_device
, chrdev
);
416 /* Fail on open if the backing gpiochip is gone */
417 if (!gdev
|| !gdev
->chip
)
419 get_device(&gdev
->dev
);
420 filp
->private_data
= gdev
;
425 * gpio_chrdev_release() - close chardev after ioctl operations
426 * @inode: inode for this chardev
427 * @filp: file struct for storing private data
428 * Returns 0 on success
430 static int gpio_chrdev_release(struct inode
*inode
, struct file
*filp
)
432 struct gpio_device
*gdev
= container_of(inode
->i_cdev
,
433 struct gpio_device
, chrdev
);
437 put_device(&gdev
->dev
);
442 static const struct file_operations gpio_fileops
= {
443 .release
= gpio_chrdev_release
,
444 .open
= gpio_chrdev_open
,
445 .owner
= THIS_MODULE
,
446 .llseek
= noop_llseek
,
447 .unlocked_ioctl
= gpio_ioctl
,
448 .compat_ioctl
= gpio_ioctl
,
451 static void gpiodevice_release(struct device
*dev
)
453 struct gpio_device
*gdev
= dev_get_drvdata(dev
);
455 cdev_del(&gdev
->chrdev
);
456 list_del(&gdev
->list
);
457 ida_simple_remove(&gpio_ida
, gdev
->id
);
462 * gpiochip_add_data() - register a gpio_chip
463 * @chip: the chip to register, with chip->base initialized
464 * Context: potentially before irqs will work
466 * Returns a negative errno if the chip can't be registered, such as
467 * because the chip->base is invalid or already associated with a
468 * different chip. Otherwise it returns zero as a success code.
470 * When gpiochip_add_data() is called very early during boot, so that GPIOs
471 * can be freely used, the chip->parent device must be registered before
472 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
473 * for GPIOs will fail rudely.
475 * If chip->base is negative, this requests dynamic assignment of
476 * a range of valid GPIOs.
478 int gpiochip_add_data(struct gpio_chip
*chip
, void *data
)
483 int base
= chip
->base
;
484 struct gpio_device
*gdev
;
487 * First: allocate and populate the internal stat container, and
488 * set up the struct device.
490 gdev
= kzalloc(sizeof(*gdev
), GFP_KERNEL
);
493 gdev
->dev
.bus
= &gpio_bus_type
;
495 chip
->gpiodev
= gdev
;
497 gdev
->dev
.parent
= chip
->parent
;
498 gdev
->dev
.of_node
= chip
->parent
->of_node
;
500 #ifdef CONFIG_OF_GPIO
501 /* If the gpiochip has an assigned OF node this takes precedence */
503 gdev
->dev
.of_node
= chip
->of_node
;
506 gdev
->id
= ida_simple_get(&gpio_ida
, 0, 0, GFP_KERNEL
);
511 dev_set_name(&gdev
->dev
, "gpiochip%d", gdev
->id
);
512 device_initialize(&gdev
->dev
);
513 dev_set_drvdata(&gdev
->dev
, gdev
);
514 if (chip
->parent
&& chip
->parent
->driver
)
515 gdev
->owner
= chip
->parent
->driver
->owner
;
516 else if (chip
->owner
)
517 /* TODO: remove chip->owner */
518 gdev
->owner
= chip
->owner
;
520 gdev
->owner
= THIS_MODULE
;
522 gdev
->descs
= devm_kcalloc(&gdev
->dev
, chip
->ngpio
,
523 sizeof(gdev
->descs
[0]), GFP_KERNEL
);
529 if (chip
->ngpio
== 0) {
530 chip_err(chip
, "tried to insert a GPIO chip with zero lines\n");
536 gdev
->label
= devm_kstrdup(&gdev
->dev
, chip
->label
, GFP_KERNEL
);
538 gdev
->label
= devm_kstrdup(&gdev
->dev
, "unknown", GFP_KERNEL
);
544 gdev
->ngpio
= chip
->ngpio
;
547 spin_lock_irqsave(&gpio_lock
, flags
);
550 * TODO: this allocates a Linux GPIO number base in the global
551 * GPIO numberspace for this chip. In the long run we want to
552 * get *rid* of this numberspace and use only descriptors, but
553 * it may be a pipe dream. It will not happen before we get rid
554 * of the sysfs interface anyways.
557 base
= gpiochip_find_base(chip
->ngpio
);
560 spin_unlock_irqrestore(&gpio_lock
, flags
);
564 * TODO: it should not be necessary to reflect the assigned
565 * base outside of the GPIO subsystem. Go over drivers and
566 * see if anyone makes use of this, else drop this and assign
573 status
= gpiodev_add_to_list(gdev
);
575 spin_unlock_irqrestore(&gpio_lock
, flags
);
579 for (i
= 0; i
< chip
->ngpio
; i
++) {
580 struct gpio_desc
*desc
= &gdev
->descs
[i
];
584 /* REVISIT: most hardware initializes GPIOs as inputs (often
585 * with pullups enabled) so power usage is minimized. Linux
586 * code should set the gpio direction first thing; but until
587 * it does, and in case chip->get_direction is not set, we may
588 * expose the wrong direction in sysfs.
590 desc
->flags
= !chip
->direction_input
? (1 << FLAG_IS_OUT
) : 0;
593 spin_unlock_irqrestore(&gpio_lock
, flags
);
595 #ifdef CONFIG_PINCTRL
596 INIT_LIST_HEAD(&gdev
->pin_ranges
);
599 status
= gpiochip_set_desc_names(chip
);
601 goto err_remove_from_list
;
603 status
= of_gpiochip_add(chip
);
605 goto err_remove_chip
;
607 acpi_gpiochip_add(chip
);
610 * By first adding the chardev, and then adding the device,
611 * we get a device node entry in sysfs under
612 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
613 * coldplug of device nodes and other udev business.
615 cdev_init(&gdev
->chrdev
, &gpio_fileops
);
616 gdev
->chrdev
.owner
= THIS_MODULE
;
617 gdev
->chrdev
.kobj
.parent
= &gdev
->dev
.kobj
;
618 gdev
->dev
.devt
= MKDEV(MAJOR(gpio_devt
), gdev
->id
);
619 status
= cdev_add(&gdev
->chrdev
, gdev
->dev
.devt
, 1);
621 chip_warn(chip
, "failed to add char device %d:%d\n",
622 MAJOR(gpio_devt
), gdev
->id
);
624 chip_dbg(chip
, "added GPIO chardev (%d:%d)\n",
625 MAJOR(gpio_devt
), gdev
->id
);
626 status
= device_add(&gdev
->dev
);
628 goto err_remove_chardev
;
630 status
= gpiochip_sysfs_register(gdev
);
632 goto err_remove_device
;
634 /* From this point, the .release() function cleans up gpio_device */
635 gdev
->dev
.release
= gpiodevice_release
;
636 get_device(&gdev
->dev
);
637 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
638 __func__
, gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1,
639 dev_name(&gdev
->dev
), chip
->label
? : "generic");
644 device_del(&gdev
->dev
);
646 cdev_del(&gdev
->chrdev
);
648 acpi_gpiochip_remove(chip
);
649 gpiochip_free_hogs(chip
);
650 of_gpiochip_remove(chip
);
651 err_remove_from_list
:
652 spin_lock_irqsave(&gpio_lock
, flags
);
653 list_del(&gdev
->list
);
654 spin_unlock_irqrestore(&gpio_lock
, flags
);
656 ida_simple_remove(&gpio_ida
, gdev
->id
);
657 /* failures here can mean systems won't boot... */
658 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__
,
659 gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1,
660 chip
->label
? : "generic");
664 EXPORT_SYMBOL_GPL(gpiochip_add_data
);
667 * gpiochip_get_data() - get per-subdriver data for the chip
669 void *gpiochip_get_data(struct gpio_chip
*chip
)
671 return chip
->gpiodev
->data
;
673 EXPORT_SYMBOL_GPL(gpiochip_get_data
);
676 * gpiochip_remove() - unregister a gpio_chip
677 * @chip: the chip to unregister
679 * A gpio_chip with any GPIOs still requested may not be removed.
681 void gpiochip_remove(struct gpio_chip
*chip
)
683 struct gpio_device
*gdev
= chip
->gpiodev
;
684 struct gpio_desc
*desc
;
687 bool requested
= false;
689 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
690 gpiochip_sysfs_unregister(gdev
);
691 /* Numb the device, cancelling all outstanding operations */
693 gpiochip_irqchip_remove(chip
);
694 acpi_gpiochip_remove(chip
);
695 gpiochip_remove_pin_ranges(chip
);
696 gpiochip_free_hogs(chip
);
697 of_gpiochip_remove(chip
);
699 * We accept no more calls into the driver from this point, so
700 * NULL the driver data pointer
704 spin_lock_irqsave(&gpio_lock
, flags
);
705 for (i
= 0; i
< gdev
->ngpio
; i
++) {
706 desc
= &gdev
->descs
[i
];
707 if (test_bit(FLAG_REQUESTED
, &desc
->flags
))
710 spin_unlock_irqrestore(&gpio_lock
, flags
);
714 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
717 * The gpiochip side puts its use of the device to rest here:
718 * if there are no userspace clients, the chardev and device will
719 * be removed, else it will be dangling until the last user is
722 put_device(&gdev
->dev
);
724 EXPORT_SYMBOL_GPL(gpiochip_remove
);
727 * gpiochip_find() - iterator for locating a specific gpio_chip
728 * @data: data to pass to match function
729 * @callback: Callback function to check gpio_chip
731 * Similar to bus_find_device. It returns a reference to a gpio_chip as
732 * determined by a user supplied @match callback. The callback should return
733 * 0 if the device doesn't match and non-zero if it does. If the callback is
734 * non-zero, this function will return to the caller and not iterate over any
737 struct gpio_chip
*gpiochip_find(void *data
,
738 int (*match
)(struct gpio_chip
*chip
,
741 struct gpio_device
*gdev
;
742 struct gpio_chip
*chip
;
745 spin_lock_irqsave(&gpio_lock
, flags
);
746 list_for_each_entry(gdev
, &gpio_devices
, list
)
747 if (match(gdev
->chip
, data
))
751 if (&gdev
->list
== &gpio_devices
)
756 spin_unlock_irqrestore(&gpio_lock
, flags
);
760 EXPORT_SYMBOL_GPL(gpiochip_find
);
762 static int gpiochip_match_name(struct gpio_chip
*chip
, void *data
)
764 const char *name
= data
;
766 return !strcmp(chip
->label
, name
);
769 static struct gpio_chip
*find_chip_by_name(const char *name
)
771 return gpiochip_find((void *)name
, gpiochip_match_name
);
774 #ifdef CONFIG_GPIOLIB_IRQCHIP
777 * The following is irqchip helper code for gpiochips.
781 * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
782 * @gpiochip: the gpiochip to set the irqchip chain to
783 * @irqchip: the irqchip to chain to the gpiochip
784 * @parent_irq: the irq number corresponding to the parent IRQ for this
786 * @parent_handler: the parent interrupt handler for the accumulated IRQ
787 * coming out of the gpiochip. If the interrupt is nested rather than
788 * cascaded, pass NULL in this handler argument
790 void gpiochip_set_chained_irqchip(struct gpio_chip
*gpiochip
,
791 struct irq_chip
*irqchip
,
793 irq_flow_handler_t parent_handler
)
797 if (!gpiochip
->irqdomain
) {
798 chip_err(gpiochip
, "called %s before setting up irqchip\n",
803 if (parent_handler
) {
804 if (gpiochip
->can_sleep
) {
806 "you cannot have chained interrupts on a "
807 "chip that may sleep\n");
811 * The parent irqchip is already using the chip_data for this
812 * irqchip, so our callbacks simply use the handler_data.
814 irq_set_chained_handler_and_data(parent_irq
, parent_handler
,
817 gpiochip
->irq_parent
= parent_irq
;
820 /* Set the parent IRQ for all affected IRQs */
821 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++)
822 irq_set_parent(irq_find_mapping(gpiochip
->irqdomain
, offset
),
825 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip
);
828 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
829 * @d: the irqdomain used by this irqchip
830 * @irq: the global irq number used by this GPIO irqchip irq
831 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
833 * This function will set up the mapping for a certain IRQ line on a
834 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
835 * stored inside the gpiochip.
837 static int gpiochip_irq_map(struct irq_domain
*d
, unsigned int irq
,
838 irq_hw_number_t hwirq
)
840 struct gpio_chip
*chip
= d
->host_data
;
842 irq_set_chip_data(irq
, chip
);
844 * This lock class tells lockdep that GPIO irqs are in a different
845 * category than their parents, so it won't report false recursion.
847 irq_set_lockdep_class(irq
, chip
->lock_key
);
848 irq_set_chip_and_handler(irq
, chip
->irqchip
, chip
->irq_handler
);
849 /* Chips that can sleep need nested thread handlers */
850 if (chip
->can_sleep
&& !chip
->irq_not_threaded
)
851 irq_set_nested_thread(irq
, 1);
852 irq_set_noprobe(irq
);
855 * No set-up of the hardware will happen if IRQ_TYPE_NONE
856 * is passed as default type.
858 if (chip
->irq_default_type
!= IRQ_TYPE_NONE
)
859 irq_set_irq_type(irq
, chip
->irq_default_type
);
864 static void gpiochip_irq_unmap(struct irq_domain
*d
, unsigned int irq
)
866 struct gpio_chip
*chip
= d
->host_data
;
869 irq_set_nested_thread(irq
, 0);
870 irq_set_chip_and_handler(irq
, NULL
, NULL
);
871 irq_set_chip_data(irq
, NULL
);
874 static const struct irq_domain_ops gpiochip_domain_ops
= {
875 .map
= gpiochip_irq_map
,
876 .unmap
= gpiochip_irq_unmap
,
877 /* Virtually all GPIO irqchips are twocell:ed */
878 .xlate
= irq_domain_xlate_twocell
,
881 static int gpiochip_irq_reqres(struct irq_data
*d
)
883 struct gpio_chip
*chip
= irq_data_get_irq_chip_data(d
);
885 if (!try_module_get(chip
->gpiodev
->owner
))
888 if (gpiochip_lock_as_irq(chip
, d
->hwirq
)) {
890 "unable to lock HW IRQ %lu for IRQ\n",
892 module_put(chip
->gpiodev
->owner
);
898 static void gpiochip_irq_relres(struct irq_data
*d
)
900 struct gpio_chip
*chip
= irq_data_get_irq_chip_data(d
);
902 gpiochip_unlock_as_irq(chip
, d
->hwirq
);
903 module_put(chip
->gpiodev
->owner
);
906 static int gpiochip_to_irq(struct gpio_chip
*chip
, unsigned offset
)
908 return irq_find_mapping(chip
->irqdomain
, offset
);
912 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
913 * @gpiochip: the gpiochip to remove the irqchip from
915 * This is called only from gpiochip_remove()
917 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
)
921 acpi_gpiochip_free_interrupts(gpiochip
);
923 if (gpiochip
->irq_parent
) {
924 irq_set_chained_handler(gpiochip
->irq_parent
, NULL
);
925 irq_set_handler_data(gpiochip
->irq_parent
, NULL
);
928 /* Remove all IRQ mappings and delete the domain */
929 if (gpiochip
->irqdomain
) {
930 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++)
932 irq_find_mapping(gpiochip
->irqdomain
, offset
));
933 irq_domain_remove(gpiochip
->irqdomain
);
936 if (gpiochip
->irqchip
) {
937 gpiochip
->irqchip
->irq_request_resources
= NULL
;
938 gpiochip
->irqchip
->irq_release_resources
= NULL
;
939 gpiochip
->irqchip
= NULL
;
944 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
945 * @gpiochip: the gpiochip to add the irqchip to
946 * @irqchip: the irqchip to add to the gpiochip
947 * @first_irq: if not dynamically assigned, the base (first) IRQ to
948 * allocate gpiochip irqs from
949 * @handler: the irq handler to use (often a predefined irq core function)
950 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
951 * to have the core avoid setting up any default type in the hardware.
952 * @lock_key: lockdep class
954 * This function closely associates a certain irqchip with a certain
955 * gpiochip, providing an irq domain to translate the local IRQs to
956 * global irqs in the gpiolib core, and making sure that the gpiochip
957 * is passed as chip data to all related functions. Driver callbacks
958 * need to use gpiochip_get_data() to get their local state containers back
959 * from the gpiochip passed as chip data. An irqdomain will be stored
960 * in the gpiochip that shall be used by the driver to handle IRQ number
961 * translation. The gpiochip will need to be initialized and registered
962 * before calling this function.
964 * This function will handle two cell:ed simple IRQs and assumes all
965 * the pins on the gpiochip can generate a unique IRQ. Everything else
966 * need to be open coded.
968 int _gpiochip_irqchip_add(struct gpio_chip
*gpiochip
,
969 struct irq_chip
*irqchip
,
970 unsigned int first_irq
,
971 irq_flow_handler_t handler
,
973 struct lock_class_key
*lock_key
)
975 struct device_node
*of_node
;
977 unsigned irq_base
= 0;
979 if (!gpiochip
|| !irqchip
)
982 if (!gpiochip
->parent
) {
983 pr_err("missing gpiochip .dev parent pointer\n");
986 of_node
= gpiochip
->parent
->of_node
;
987 #ifdef CONFIG_OF_GPIO
989 * If the gpiochip has an assigned OF node this takes precedence
990 * FIXME: get rid of this and use gpiochip->parent->of_node
993 if (gpiochip
->of_node
)
994 of_node
= gpiochip
->of_node
;
996 gpiochip
->irqchip
= irqchip
;
997 gpiochip
->irq_handler
= handler
;
998 gpiochip
->irq_default_type
= type
;
999 gpiochip
->to_irq
= gpiochip_to_irq
;
1000 gpiochip
->lock_key
= lock_key
;
1001 gpiochip
->irqdomain
= irq_domain_add_simple(of_node
,
1002 gpiochip
->ngpio
, first_irq
,
1003 &gpiochip_domain_ops
, gpiochip
);
1004 if (!gpiochip
->irqdomain
) {
1005 gpiochip
->irqchip
= NULL
;
1010 * It is possible for a driver to override this, but only if the
1011 * alternative functions are both implemented.
1013 if (!irqchip
->irq_request_resources
&&
1014 !irqchip
->irq_release_resources
) {
1015 irqchip
->irq_request_resources
= gpiochip_irq_reqres
;
1016 irqchip
->irq_release_resources
= gpiochip_irq_relres
;
1020 * Prepare the mapping since the irqchip shall be orthogonal to
1021 * any gpiochip calls. If the first_irq was zero, this is
1022 * necessary to allocate descriptors for all IRQs.
1024 for (offset
= 0; offset
< gpiochip
->ngpio
; offset
++) {
1025 irq_base
= irq_create_mapping(gpiochip
->irqdomain
, offset
);
1028 * Store the base into the gpiochip to be used when
1029 * unmapping the irqs.
1031 gpiochip
->irq_base
= irq_base
;
1034 acpi_gpiochip_request_interrupts(gpiochip
);
1038 EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add
);
1040 #else /* CONFIG_GPIOLIB_IRQCHIP */
1042 static void gpiochip_irqchip_remove(struct gpio_chip
*gpiochip
) {}
1044 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1047 * gpiochip_generic_request() - request the gpio function for a pin
1048 * @chip: the gpiochip owning the GPIO
1049 * @offset: the offset of the GPIO to request for GPIO function
1051 int gpiochip_generic_request(struct gpio_chip
*chip
, unsigned offset
)
1053 return pinctrl_request_gpio(chip
->gpiodev
->base
+ offset
);
1055 EXPORT_SYMBOL_GPL(gpiochip_generic_request
);
1058 * gpiochip_generic_free() - free the gpio function from a pin
1059 * @chip: the gpiochip to request the gpio function for
1060 * @offset: the offset of the GPIO to free from GPIO function
1062 void gpiochip_generic_free(struct gpio_chip
*chip
, unsigned offset
)
1064 pinctrl_free_gpio(chip
->gpiodev
->base
+ offset
);
1066 EXPORT_SYMBOL_GPL(gpiochip_generic_free
);
1068 #ifdef CONFIG_PINCTRL
1071 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1072 * @chip: the gpiochip to add the range for
1073 * @pctldev: the pin controller to map to
1074 * @gpio_offset: the start offset in the current gpio_chip number space
1075 * @pin_group: name of the pin group inside the pin controller
1077 int gpiochip_add_pingroup_range(struct gpio_chip
*chip
,
1078 struct pinctrl_dev
*pctldev
,
1079 unsigned int gpio_offset
, const char *pin_group
)
1081 struct gpio_pin_range
*pin_range
;
1082 struct gpio_device
*gdev
= chip
->gpiodev
;
1085 pin_range
= kzalloc(sizeof(*pin_range
), GFP_KERNEL
);
1087 chip_err(chip
, "failed to allocate pin ranges\n");
1091 /* Use local offset as range ID */
1092 pin_range
->range
.id
= gpio_offset
;
1093 pin_range
->range
.gc
= chip
;
1094 pin_range
->range
.name
= chip
->label
;
1095 pin_range
->range
.base
= gdev
->base
+ gpio_offset
;
1096 pin_range
->pctldev
= pctldev
;
1098 ret
= pinctrl_get_group_pins(pctldev
, pin_group
,
1099 &pin_range
->range
.pins
,
1100 &pin_range
->range
.npins
);
1106 pinctrl_add_gpio_range(pctldev
, &pin_range
->range
);
1108 chip_dbg(chip
, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1109 gpio_offset
, gpio_offset
+ pin_range
->range
.npins
- 1,
1110 pinctrl_dev_get_devname(pctldev
), pin_group
);
1112 list_add_tail(&pin_range
->node
, &gdev
->pin_ranges
);
1116 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range
);
1119 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1120 * @chip: the gpiochip to add the range for
1121 * @pinctrl_name: the dev_name() of the pin controller to map to
1122 * @gpio_offset: the start offset in the current gpio_chip number space
1123 * @pin_offset: the start offset in the pin controller number space
1124 * @npins: the number of pins from the offset of each pin space (GPIO and
1125 * pin controller) to accumulate in this range
1127 int gpiochip_add_pin_range(struct gpio_chip
*chip
, const char *pinctl_name
,
1128 unsigned int gpio_offset
, unsigned int pin_offset
,
1131 struct gpio_pin_range
*pin_range
;
1132 struct gpio_device
*gdev
= chip
->gpiodev
;
1135 pin_range
= kzalloc(sizeof(*pin_range
), GFP_KERNEL
);
1137 chip_err(chip
, "failed to allocate pin ranges\n");
1141 /* Use local offset as range ID */
1142 pin_range
->range
.id
= gpio_offset
;
1143 pin_range
->range
.gc
= chip
;
1144 pin_range
->range
.name
= chip
->label
;
1145 pin_range
->range
.base
= gdev
->base
+ gpio_offset
;
1146 pin_range
->range
.pin_base
= pin_offset
;
1147 pin_range
->range
.npins
= npins
;
1148 pin_range
->pctldev
= pinctrl_find_and_add_gpio_range(pinctl_name
,
1150 if (IS_ERR(pin_range
->pctldev
)) {
1151 ret
= PTR_ERR(pin_range
->pctldev
);
1152 chip_err(chip
, "could not create pin range\n");
1156 chip_dbg(chip
, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1157 gpio_offset
, gpio_offset
+ npins
- 1,
1159 pin_offset
, pin_offset
+ npins
- 1);
1161 list_add_tail(&pin_range
->node
, &gdev
->pin_ranges
);
1165 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range
);
1168 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1169 * @chip: the chip to remove all the mappings for
1171 void gpiochip_remove_pin_ranges(struct gpio_chip
*chip
)
1173 struct gpio_pin_range
*pin_range
, *tmp
;
1174 struct gpio_device
*gdev
= chip
->gpiodev
;
1176 list_for_each_entry_safe(pin_range
, tmp
, &gdev
->pin_ranges
, node
) {
1177 list_del(&pin_range
->node
);
1178 pinctrl_remove_gpio_range(pin_range
->pctldev
,
1183 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges
);
1185 #endif /* CONFIG_PINCTRL */
1187 /* These "optional" allocation calls help prevent drivers from stomping
1188 * on each other, and help provide better diagnostics in debugfs.
1189 * They're called even less than the "set direction" calls.
1191 static int __gpiod_request(struct gpio_desc
*desc
, const char *label
)
1193 struct gpio_chip
*chip
= desc
->gdev
->chip
;
1195 unsigned long flags
;
1197 spin_lock_irqsave(&gpio_lock
, flags
);
1199 /* NOTE: gpio_request() can be called in early boot,
1200 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1203 if (test_and_set_bit(FLAG_REQUESTED
, &desc
->flags
) == 0) {
1204 desc_set_label(desc
, label
? : "?");
1211 if (chip
->request
) {
1212 /* chip->request may sleep */
1213 spin_unlock_irqrestore(&gpio_lock
, flags
);
1214 status
= chip
->request(chip
, gpio_chip_hwgpio(desc
));
1215 spin_lock_irqsave(&gpio_lock
, flags
);
1218 desc_set_label(desc
, NULL
);
1219 clear_bit(FLAG_REQUESTED
, &desc
->flags
);
1223 if (chip
->get_direction
) {
1224 /* chip->get_direction may sleep */
1225 spin_unlock_irqrestore(&gpio_lock
, flags
);
1226 gpiod_get_direction(desc
);
1227 spin_lock_irqsave(&gpio_lock
, flags
);
1231 /* Clear flags that might have been set by the caller before
1232 * requesting the GPIO.
1234 clear_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
1235 clear_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
1236 clear_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
1238 spin_unlock_irqrestore(&gpio_lock
, flags
);
1243 * This descriptor validation needs to be inserted verbatim into each
1244 * function taking a descriptor, so we need to use a preprocessor
1245 * macro to avoid endless duplication.
1247 #define VALIDATE_DESC(desc) do { \
1248 if (!desc || !desc->gdev) { \
1249 pr_warn("%s: invalid GPIO\n", __func__); \
1252 if ( !desc->gdev->chip ) { \
1253 dev_warn(&desc->gdev->dev, \
1254 "%s: backing chip is gone\n", __func__); \
1258 #define VALIDATE_DESC_VOID(desc) do { \
1259 if (!desc || !desc->gdev) { \
1260 pr_warn("%s: invalid GPIO\n", __func__); \
1263 if (!desc->gdev->chip) { \
1264 dev_warn(&desc->gdev->dev, \
1265 "%s: backing chip is gone\n", __func__); \
1270 int gpiod_request(struct gpio_desc
*desc
, const char *label
)
1272 int status
= -EPROBE_DEFER
;
1273 struct gpio_device
*gdev
;
1275 VALIDATE_DESC(desc
);
1278 if (try_module_get(gdev
->owner
)) {
1279 status
= __gpiod_request(desc
, label
);
1281 module_put(gdev
->owner
);
1283 get_device(&gdev
->dev
);
1287 gpiod_dbg(desc
, "%s: status %d\n", __func__
, status
);
1292 static bool __gpiod_free(struct gpio_desc
*desc
)
1295 unsigned long flags
;
1296 struct gpio_chip
*chip
;
1300 gpiod_unexport(desc
);
1302 spin_lock_irqsave(&gpio_lock
, flags
);
1304 chip
= desc
->gdev
->chip
;
1305 if (chip
&& test_bit(FLAG_REQUESTED
, &desc
->flags
)) {
1307 spin_unlock_irqrestore(&gpio_lock
, flags
);
1308 might_sleep_if(chip
->can_sleep
);
1309 chip
->free(chip
, gpio_chip_hwgpio(desc
));
1310 spin_lock_irqsave(&gpio_lock
, flags
);
1312 desc_set_label(desc
, NULL
);
1313 clear_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
1314 clear_bit(FLAG_REQUESTED
, &desc
->flags
);
1315 clear_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
1316 clear_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
1317 clear_bit(FLAG_IS_HOGGED
, &desc
->flags
);
1321 spin_unlock_irqrestore(&gpio_lock
, flags
);
1325 void gpiod_free(struct gpio_desc
*desc
)
1327 if (desc
&& desc
->gdev
&& __gpiod_free(desc
)) {
1328 module_put(desc
->gdev
->owner
);
1329 put_device(&desc
->gdev
->dev
);
1331 WARN_ON(extra_checks
);
1336 * gpiochip_is_requested - return string iff signal was requested
1337 * @chip: controller managing the signal
1338 * @offset: of signal within controller's 0..(ngpio - 1) range
1340 * Returns NULL if the GPIO is not currently requested, else a string.
1341 * The string returned is the label passed to gpio_request(); if none has been
1342 * passed it is a meaningless, non-NULL constant.
1344 * This function is for use by GPIO controller drivers. The label can
1345 * help with diagnostics, and knowing that the signal is used as a GPIO
1346 * can help avoid accidentally multiplexing it to another controller.
1348 const char *gpiochip_is_requested(struct gpio_chip
*chip
, unsigned offset
)
1350 struct gpio_desc
*desc
;
1352 if (offset
>= chip
->ngpio
)
1355 desc
= &chip
->gpiodev
->descs
[offset
];
1357 if (test_bit(FLAG_REQUESTED
, &desc
->flags
) == 0)
1361 EXPORT_SYMBOL_GPL(gpiochip_is_requested
);
1364 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
1365 * @desc: GPIO descriptor to request
1366 * @label: label for the GPIO
1368 * Function allows GPIO chip drivers to request and use their own GPIO
1369 * descriptors via gpiolib API. Difference to gpiod_request() is that this
1370 * function will not increase reference count of the GPIO chip module. This
1371 * allows the GPIO chip module to be unloaded as needed (we assume that the
1372 * GPIO chip driver handles freeing the GPIOs it has requested).
1374 struct gpio_desc
*gpiochip_request_own_desc(struct gpio_chip
*chip
, u16 hwnum
,
1377 struct gpio_desc
*desc
= gpiochip_get_desc(chip
, hwnum
);
1381 chip_err(chip
, "failed to get GPIO descriptor\n");
1385 err
= __gpiod_request(desc
, label
);
1387 return ERR_PTR(err
);
1391 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc
);
1394 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
1395 * @desc: GPIO descriptor to free
1397 * Function frees the given GPIO requested previously with
1398 * gpiochip_request_own_desc().
1400 void gpiochip_free_own_desc(struct gpio_desc
*desc
)
1405 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc
);
1408 * Drivers MUST set GPIO direction before making get/set calls. In
1409 * some cases this is done in early boot, before IRQs are enabled.
1411 * As a rule these aren't called more than once (except for drivers
1412 * using the open-drain emulation idiom) so these are natural places
1413 * to accumulate extra debugging checks. Note that we can't (yet)
1414 * rely on gpio_request() having been called beforehand.
1418 * gpiod_direction_input - set the GPIO direction to input
1419 * @desc: GPIO to set to input
1421 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
1422 * be called safely on it.
1424 * Return 0 in case of success, else an error code.
1426 int gpiod_direction_input(struct gpio_desc
*desc
)
1428 struct gpio_chip
*chip
;
1429 int status
= -EINVAL
;
1431 VALIDATE_DESC(desc
);
1432 chip
= desc
->gdev
->chip
;
1434 if (!chip
->get
|| !chip
->direction_input
) {
1436 "%s: missing get() or direction_input() operations\n",
1441 status
= chip
->direction_input(chip
, gpio_chip_hwgpio(desc
));
1443 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
1445 trace_gpio_direction(desc_to_gpio(desc
), 1, status
);
1449 EXPORT_SYMBOL_GPL(gpiod_direction_input
);
1451 static int _gpiod_direction_output_raw(struct gpio_desc
*desc
, int value
)
1453 struct gpio_chip
*chip
;
1454 int status
= -EINVAL
;
1456 /* GPIOs used for IRQs shall not be set as output */
1457 if (test_bit(FLAG_USED_AS_IRQ
, &desc
->flags
)) {
1459 "%s: tried to set a GPIO tied to an IRQ as output\n",
1464 /* Open drain pin should not be driven to 1 */
1465 if (value
&& test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
))
1466 return gpiod_direction_input(desc
);
1468 /* Open source pin should not be driven to 0 */
1469 if (!value
&& test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
))
1470 return gpiod_direction_input(desc
);
1472 chip
= desc
->gdev
->chip
;
1473 if (!chip
->set
|| !chip
->direction_output
) {
1475 "%s: missing set() or direction_output() operations\n",
1480 status
= chip
->direction_output(chip
, gpio_chip_hwgpio(desc
), value
);
1482 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1483 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
1484 trace_gpio_direction(desc_to_gpio(desc
), 0, status
);
1489 * gpiod_direction_output_raw - set the GPIO direction to output
1490 * @desc: GPIO to set to output
1491 * @value: initial output value of the GPIO
1493 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1494 * be called safely on it. The initial value of the output must be specified
1495 * as raw value on the physical line without regard for the ACTIVE_LOW status.
1497 * Return 0 in case of success, else an error code.
1499 int gpiod_direction_output_raw(struct gpio_desc
*desc
, int value
)
1501 VALIDATE_DESC(desc
);
1502 return _gpiod_direction_output_raw(desc
, value
);
1504 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw
);
1507 * gpiod_direction_output - set the GPIO direction to output
1508 * @desc: GPIO to set to output
1509 * @value: initial output value of the GPIO
1511 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1512 * be called safely on it. The initial value of the output must be specified
1513 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1516 * Return 0 in case of success, else an error code.
1518 int gpiod_direction_output(struct gpio_desc
*desc
, int value
)
1520 VALIDATE_DESC(desc
);
1521 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1523 return _gpiod_direction_output_raw(desc
, value
);
1525 EXPORT_SYMBOL_GPL(gpiod_direction_output
);
1528 * gpiod_set_debounce - sets @debounce time for a @gpio
1529 * @gpio: the gpio to set debounce time
1530 * @debounce: debounce time is microseconds
1532 * returns -ENOTSUPP if the controller does not support setting
1535 int gpiod_set_debounce(struct gpio_desc
*desc
, unsigned debounce
)
1537 struct gpio_chip
*chip
;
1539 VALIDATE_DESC(desc
);
1540 chip
= desc
->gdev
->chip
;
1541 if (!chip
->set
|| !chip
->set_debounce
) {
1543 "%s: missing set() or set_debounce() operations\n",
1548 return chip
->set_debounce(chip
, gpio_chip_hwgpio(desc
), debounce
);
1550 EXPORT_SYMBOL_GPL(gpiod_set_debounce
);
1553 * gpiod_is_active_low - test whether a GPIO is active-low or not
1554 * @desc: the gpio descriptor to test
1556 * Returns 1 if the GPIO is active-low, 0 otherwise.
1558 int gpiod_is_active_low(const struct gpio_desc
*desc
)
1560 VALIDATE_DESC(desc
);
1561 return test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
1563 EXPORT_SYMBOL_GPL(gpiod_is_active_low
);
1565 /* I/O calls are only valid after configuration completed; the relevant
1566 * "is this a valid GPIO" error checks should already have been done.
1568 * "Get" operations are often inlinable as reading a pin value register,
1569 * and masking the relevant bit in that register.
1571 * When "set" operations are inlinable, they involve writing that mask to
1572 * one register to set a low value, or a different register to set it high.
1573 * Otherwise locking is needed, so there may be little value to inlining.
1575 *------------------------------------------------------------------------
1577 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
1578 * have requested the GPIO. That can include implicit requesting by
1579 * a direction setting call. Marking a gpio as requested locks its chip
1580 * in memory, guaranteeing that these table lookups need no more locking
1581 * and that gpiochip_remove() will fail.
1583 * REVISIT when debugging, consider adding some instrumentation to ensure
1584 * that the GPIO was actually requested.
1587 static int _gpiod_get_raw_value(const struct gpio_desc
*desc
)
1589 struct gpio_chip
*chip
;
1593 chip
= desc
->gdev
->chip
;
1594 offset
= gpio_chip_hwgpio(desc
);
1595 value
= chip
->get
? chip
->get(chip
, offset
) : -EIO
;
1596 value
= value
< 0 ? value
: !!value
;
1597 trace_gpio_value(desc_to_gpio(desc
), 1, value
);
1602 * gpiod_get_raw_value() - return a gpio's raw value
1603 * @desc: gpio whose value will be returned
1605 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1606 * its ACTIVE_LOW status, or negative errno on failure.
1608 * This function should be called from contexts where we cannot sleep, and will
1609 * complain if the GPIO chip functions potentially sleep.
1611 int gpiod_get_raw_value(const struct gpio_desc
*desc
)
1613 VALIDATE_DESC(desc
);
1614 /* Should be using gpio_get_value_cansleep() */
1615 WARN_ON(desc
->gdev
->chip
->can_sleep
);
1616 return _gpiod_get_raw_value(desc
);
1618 EXPORT_SYMBOL_GPL(gpiod_get_raw_value
);
1621 * gpiod_get_value() - return a gpio's value
1622 * @desc: gpio whose value will be returned
1624 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1625 * account, or negative errno on failure.
1627 * This function should be called from contexts where we cannot sleep, and will
1628 * complain if the GPIO chip functions potentially sleep.
1630 int gpiod_get_value(const struct gpio_desc
*desc
)
1634 VALIDATE_DESC(desc
);
1635 /* Should be using gpio_get_value_cansleep() */
1636 WARN_ON(desc
->gdev
->chip
->can_sleep
);
1638 value
= _gpiod_get_raw_value(desc
);
1642 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1647 EXPORT_SYMBOL_GPL(gpiod_get_value
);
1650 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
1651 * @desc: gpio descriptor whose state need to be set.
1652 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1654 static void _gpio_set_open_drain_value(struct gpio_desc
*desc
, bool value
)
1657 struct gpio_chip
*chip
= desc
->gdev
->chip
;
1658 int offset
= gpio_chip_hwgpio(desc
);
1661 err
= chip
->direction_input(chip
, offset
);
1663 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
1665 err
= chip
->direction_output(chip
, offset
, 0);
1667 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1669 trace_gpio_direction(desc_to_gpio(desc
), value
, err
);
1672 "%s: Error in set_value for open drain err %d\n",
1677 * _gpio_set_open_source_value() - Set the open source gpio's value.
1678 * @desc: gpio descriptor whose state need to be set.
1679 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1681 static void _gpio_set_open_source_value(struct gpio_desc
*desc
, bool value
)
1684 struct gpio_chip
*chip
= desc
->gdev
->chip
;
1685 int offset
= gpio_chip_hwgpio(desc
);
1688 err
= chip
->direction_output(chip
, offset
, 1);
1690 set_bit(FLAG_IS_OUT
, &desc
->flags
);
1692 err
= chip
->direction_input(chip
, offset
);
1694 clear_bit(FLAG_IS_OUT
, &desc
->flags
);
1696 trace_gpio_direction(desc_to_gpio(desc
), !value
, err
);
1699 "%s: Error in set_value for open source err %d\n",
1703 static void _gpiod_set_raw_value(struct gpio_desc
*desc
, bool value
)
1705 struct gpio_chip
*chip
;
1707 chip
= desc
->gdev
->chip
;
1708 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
1709 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
))
1710 _gpio_set_open_drain_value(desc
, value
);
1711 else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
))
1712 _gpio_set_open_source_value(desc
, value
);
1714 chip
->set(chip
, gpio_chip_hwgpio(desc
), value
);
1718 * set multiple outputs on the same chip;
1719 * use the chip's set_multiple function if available;
1720 * otherwise set the outputs sequentially;
1721 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
1722 * defines which outputs are to be changed
1723 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
1724 * defines the values the outputs specified by mask are to be set to
1726 static void gpio_chip_set_multiple(struct gpio_chip
*chip
,
1727 unsigned long *mask
, unsigned long *bits
)
1729 if (chip
->set_multiple
) {
1730 chip
->set_multiple(chip
, mask
, bits
);
1733 for (i
= 0; i
< chip
->ngpio
; i
++) {
1734 if (mask
[BIT_WORD(i
)] == 0) {
1735 /* no more set bits in this mask word;
1736 * skip ahead to the next word */
1737 i
= (BIT_WORD(i
) + 1) * BITS_PER_LONG
- 1;
1740 /* set outputs if the corresponding mask bit is set */
1741 if (__test_and_clear_bit(i
, mask
))
1742 chip
->set(chip
, i
, test_bit(i
, bits
));
1747 static void gpiod_set_array_value_priv(bool raw
, bool can_sleep
,
1748 unsigned int array_size
,
1749 struct gpio_desc
**desc_array
,
1754 while (i
< array_size
) {
1755 struct gpio_chip
*chip
= desc_array
[i
]->gdev
->chip
;
1756 unsigned long mask
[BITS_TO_LONGS(chip
->ngpio
)];
1757 unsigned long bits
[BITS_TO_LONGS(chip
->ngpio
)];
1761 WARN_ON(chip
->can_sleep
);
1763 memset(mask
, 0, sizeof(mask
));
1765 struct gpio_desc
*desc
= desc_array
[i
];
1766 int hwgpio
= gpio_chip_hwgpio(desc
);
1767 int value
= value_array
[i
];
1769 if (!raw
&& test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1771 trace_gpio_value(desc_to_gpio(desc
), 0, value
);
1773 * collect all normal outputs belonging to the same chip
1774 * open drain and open source outputs are set individually
1776 if (test_bit(FLAG_OPEN_DRAIN
, &desc
->flags
)) {
1777 _gpio_set_open_drain_value(desc
, value
);
1778 } else if (test_bit(FLAG_OPEN_SOURCE
, &desc
->flags
)) {
1779 _gpio_set_open_source_value(desc
, value
);
1781 __set_bit(hwgpio
, mask
);
1783 __set_bit(hwgpio
, bits
);
1785 __clear_bit(hwgpio
, bits
);
1789 } while ((i
< array_size
) &&
1790 (desc_array
[i
]->gdev
->chip
== chip
));
1791 /* push collected bits to outputs */
1793 gpio_chip_set_multiple(chip
, mask
, bits
);
1798 * gpiod_set_raw_value() - assign a gpio's raw value
1799 * @desc: gpio whose value will be assigned
1800 * @value: value to assign
1802 * Set the raw value of the GPIO, i.e. the value of its physical line without
1803 * regard for its ACTIVE_LOW status.
1805 * This function should be called from contexts where we cannot sleep, and will
1806 * complain if the GPIO chip functions potentially sleep.
1808 void gpiod_set_raw_value(struct gpio_desc
*desc
, int value
)
1810 VALIDATE_DESC_VOID(desc
);
1811 /* Should be using gpio_set_value_cansleep() */
1812 WARN_ON(desc
->gdev
->chip
->can_sleep
);
1813 _gpiod_set_raw_value(desc
, value
);
1815 EXPORT_SYMBOL_GPL(gpiod_set_raw_value
);
1818 * gpiod_set_value() - assign a gpio's value
1819 * @desc: gpio whose value will be assigned
1820 * @value: value to assign
1822 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1825 * This function should be called from contexts where we cannot sleep, and will
1826 * complain if the GPIO chip functions potentially sleep.
1828 void gpiod_set_value(struct gpio_desc
*desc
, int value
)
1830 VALIDATE_DESC_VOID(desc
);
1831 /* Should be using gpio_set_value_cansleep() */
1832 WARN_ON(desc
->gdev
->chip
->can_sleep
);
1833 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
1835 _gpiod_set_raw_value(desc
, value
);
1837 EXPORT_SYMBOL_GPL(gpiod_set_value
);
1840 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
1841 * @array_size: number of elements in the descriptor / value arrays
1842 * @desc_array: array of GPIO descriptors whose values will be assigned
1843 * @value_array: array of values to assign
1845 * Set the raw values of the GPIOs, i.e. the values of the physical lines
1846 * without regard for their ACTIVE_LOW status.
1848 * This function should be called from contexts where we cannot sleep, and will
1849 * complain if the GPIO chip functions potentially sleep.
1851 void gpiod_set_raw_array_value(unsigned int array_size
,
1852 struct gpio_desc
**desc_array
, int *value_array
)
1856 gpiod_set_array_value_priv(true, false, array_size
, desc_array
,
1859 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value
);
1862 * gpiod_set_array_value() - assign values to an array of GPIOs
1863 * @array_size: number of elements in the descriptor / value arrays
1864 * @desc_array: array of GPIO descriptors whose values will be assigned
1865 * @value_array: array of values to assign
1867 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
1870 * This function should be called from contexts where we cannot sleep, and will
1871 * complain if the GPIO chip functions potentially sleep.
1873 void gpiod_set_array_value(unsigned int array_size
,
1874 struct gpio_desc
**desc_array
, int *value_array
)
1878 gpiod_set_array_value_priv(false, false, array_size
, desc_array
,
1881 EXPORT_SYMBOL_GPL(gpiod_set_array_value
);
1884 * gpiod_cansleep() - report whether gpio value access may sleep
1885 * @desc: gpio to check
1888 int gpiod_cansleep(const struct gpio_desc
*desc
)
1890 VALIDATE_DESC(desc
);
1891 return desc
->gdev
->chip
->can_sleep
;
1893 EXPORT_SYMBOL_GPL(gpiod_cansleep
);
1896 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
1897 * @desc: gpio whose IRQ will be returned (already requested)
1899 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
1902 int gpiod_to_irq(const struct gpio_desc
*desc
)
1904 struct gpio_chip
*chip
;
1907 VALIDATE_DESC(desc
);
1908 chip
= desc
->gdev
->chip
;
1909 offset
= gpio_chip_hwgpio(desc
);
1910 return chip
->to_irq
? chip
->to_irq(chip
, offset
) : -ENXIO
;
1912 EXPORT_SYMBOL_GPL(gpiod_to_irq
);
1915 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
1916 * @chip: the chip the GPIO to lock belongs to
1917 * @offset: the offset of the GPIO to lock as IRQ
1919 * This is used directly by GPIO drivers that want to lock down
1920 * a certain GPIO line to be used for IRQs.
1922 int gpiochip_lock_as_irq(struct gpio_chip
*chip
, unsigned int offset
)
1924 if (offset
>= chip
->ngpio
)
1927 if (test_bit(FLAG_IS_OUT
, &chip
->gpiodev
->descs
[offset
].flags
)) {
1929 "%s: tried to flag a GPIO set as output for IRQ\n",
1934 set_bit(FLAG_USED_AS_IRQ
, &chip
->gpiodev
->descs
[offset
].flags
);
1937 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq
);
1940 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
1941 * @chip: the chip the GPIO to lock belongs to
1942 * @offset: the offset of the GPIO to lock as IRQ
1944 * This is used directly by GPIO drivers that want to indicate
1945 * that a certain GPIO is no longer used exclusively for IRQ.
1947 void gpiochip_unlock_as_irq(struct gpio_chip
*chip
, unsigned int offset
)
1949 if (offset
>= chip
->ngpio
)
1952 clear_bit(FLAG_USED_AS_IRQ
, &chip
->gpiodev
->descs
[offset
].flags
);
1954 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq
);
1956 bool gpiochip_line_is_irq(struct gpio_chip
*chip
, unsigned int offset
)
1958 if (offset
>= chip
->ngpio
)
1961 return test_bit(FLAG_USED_AS_IRQ
, &chip
->gpiodev
->descs
[offset
].flags
);
1963 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq
);
1965 bool gpiochip_line_is_open_drain(struct gpio_chip
*chip
, unsigned int offset
)
1967 if (offset
>= chip
->ngpio
)
1970 return test_bit(FLAG_OPEN_DRAIN
, &chip
->gpiodev
->descs
[offset
].flags
);
1972 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain
);
1974 bool gpiochip_line_is_open_source(struct gpio_chip
*chip
, unsigned int offset
)
1976 if (offset
>= chip
->ngpio
)
1979 return test_bit(FLAG_OPEN_SOURCE
, &chip
->gpiodev
->descs
[offset
].flags
);
1981 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source
);
1984 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
1985 * @desc: gpio whose value will be returned
1987 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1988 * its ACTIVE_LOW status, or negative errno on failure.
1990 * This function is to be called from contexts that can sleep.
1992 int gpiod_get_raw_value_cansleep(const struct gpio_desc
*desc
)
1994 might_sleep_if(extra_checks
);
1995 VALIDATE_DESC(desc
);
1996 return _gpiod_get_raw_value(desc
);
1998 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep
);
2001 * gpiod_get_value_cansleep() - return a gpio's value
2002 * @desc: gpio whose value will be returned
2004 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2005 * account, or negative errno on failure.
2007 * This function is to be called from contexts that can sleep.
2009 int gpiod_get_value_cansleep(const struct gpio_desc
*desc
)
2013 might_sleep_if(extra_checks
);
2014 VALIDATE_DESC(desc
);
2015 value
= _gpiod_get_raw_value(desc
);
2019 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2024 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep
);
2027 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2028 * @desc: gpio whose value will be assigned
2029 * @value: value to assign
2031 * Set the raw value of the GPIO, i.e. the value of its physical line without
2032 * regard for its ACTIVE_LOW status.
2034 * This function is to be called from contexts that can sleep.
2036 void gpiod_set_raw_value_cansleep(struct gpio_desc
*desc
, int value
)
2038 might_sleep_if(extra_checks
);
2039 VALIDATE_DESC_VOID(desc
);
2040 _gpiod_set_raw_value(desc
, value
);
2042 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep
);
2045 * gpiod_set_value_cansleep() - assign a gpio's value
2046 * @desc: gpio whose value will be assigned
2047 * @value: value to assign
2049 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2052 * This function is to be called from contexts that can sleep.
2054 void gpiod_set_value_cansleep(struct gpio_desc
*desc
, int value
)
2056 might_sleep_if(extra_checks
);
2057 VALIDATE_DESC_VOID(desc
);
2058 if (test_bit(FLAG_ACTIVE_LOW
, &desc
->flags
))
2060 _gpiod_set_raw_value(desc
, value
);
2062 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep
);
2065 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2066 * @array_size: number of elements in the descriptor / value arrays
2067 * @desc_array: array of GPIO descriptors whose values will be assigned
2068 * @value_array: array of values to assign
2070 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2071 * without regard for their ACTIVE_LOW status.
2073 * This function is to be called from contexts that can sleep.
2075 void gpiod_set_raw_array_value_cansleep(unsigned int array_size
,
2076 struct gpio_desc
**desc_array
,
2079 might_sleep_if(extra_checks
);
2082 gpiod_set_array_value_priv(true, true, array_size
, desc_array
,
2085 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep
);
2088 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2089 * @array_size: number of elements in the descriptor / value arrays
2090 * @desc_array: array of GPIO descriptors whose values will be assigned
2091 * @value_array: array of values to assign
2093 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2096 * This function is to be called from contexts that can sleep.
2098 void gpiod_set_array_value_cansleep(unsigned int array_size
,
2099 struct gpio_desc
**desc_array
,
2102 might_sleep_if(extra_checks
);
2105 gpiod_set_array_value_priv(false, true, array_size
, desc_array
,
2108 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep
);
2111 * gpiod_add_lookup_table() - register GPIO device consumers
2112 * @table: table of consumers to register
2114 void gpiod_add_lookup_table(struct gpiod_lookup_table
*table
)
2116 mutex_lock(&gpio_lookup_lock
);
2118 list_add_tail(&table
->list
, &gpio_lookup_list
);
2120 mutex_unlock(&gpio_lookup_lock
);
2124 * gpiod_remove_lookup_table() - unregister GPIO device consumers
2125 * @table: table of consumers to unregister
2127 void gpiod_remove_lookup_table(struct gpiod_lookup_table
*table
)
2129 mutex_lock(&gpio_lookup_lock
);
2131 list_del(&table
->list
);
2133 mutex_unlock(&gpio_lookup_lock
);
2136 static struct gpio_desc
*of_find_gpio(struct device
*dev
, const char *con_id
,
2138 enum gpio_lookup_flags
*flags
)
2140 char prop_name
[32]; /* 32 is max size of property name */
2141 enum of_gpio_flags of_flags
;
2142 struct gpio_desc
*desc
;
2145 for (i
= 0; i
< ARRAY_SIZE(gpio_suffixes
); i
++) {
2147 snprintf(prop_name
, sizeof(prop_name
), "%s-%s", con_id
,
2150 snprintf(prop_name
, sizeof(prop_name
), "%s",
2153 desc
= of_get_named_gpiod_flags(dev
->of_node
, prop_name
, idx
,
2155 if (!IS_ERR(desc
) || (PTR_ERR(desc
) == -EPROBE_DEFER
))
2162 if (of_flags
& OF_GPIO_ACTIVE_LOW
)
2163 *flags
|= GPIO_ACTIVE_LOW
;
2165 if (of_flags
& OF_GPIO_SINGLE_ENDED
) {
2166 if (of_flags
& OF_GPIO_ACTIVE_LOW
)
2167 *flags
|= GPIO_OPEN_DRAIN
;
2169 *flags
|= GPIO_OPEN_SOURCE
;
2175 static struct gpio_desc
*acpi_find_gpio(struct device
*dev
, const char *con_id
,
2177 enum gpio_lookup_flags
*flags
)
2179 struct acpi_device
*adev
= ACPI_COMPANION(dev
);
2180 struct acpi_gpio_info info
;
2181 struct gpio_desc
*desc
;
2185 /* Try first from _DSD */
2186 for (i
= 0; i
< ARRAY_SIZE(gpio_suffixes
); i
++) {
2187 if (con_id
&& strcmp(con_id
, "gpios")) {
2188 snprintf(propname
, sizeof(propname
), "%s-%s",
2189 con_id
, gpio_suffixes
[i
]);
2191 snprintf(propname
, sizeof(propname
), "%s",
2195 desc
= acpi_get_gpiod_by_index(adev
, propname
, idx
, &info
);
2196 if (!IS_ERR(desc
) || (PTR_ERR(desc
) == -EPROBE_DEFER
))
2200 /* Then from plain _CRS GPIOs */
2202 if (!acpi_can_fallback_to_crs(adev
, con_id
))
2203 return ERR_PTR(-ENOENT
);
2205 desc
= acpi_get_gpiod_by_index(adev
, NULL
, idx
, &info
);
2210 if (info
.polarity
== GPIO_ACTIVE_LOW
)
2211 *flags
|= GPIO_ACTIVE_LOW
;
2216 static struct gpiod_lookup_table
*gpiod_find_lookup_table(struct device
*dev
)
2218 const char *dev_id
= dev
? dev_name(dev
) : NULL
;
2219 struct gpiod_lookup_table
*table
;
2221 mutex_lock(&gpio_lookup_lock
);
2223 list_for_each_entry(table
, &gpio_lookup_list
, list
) {
2224 if (table
->dev_id
&& dev_id
) {
2226 * Valid strings on both ends, must be identical to have
2229 if (!strcmp(table
->dev_id
, dev_id
))
2233 * One of the pointers is NULL, so both must be to have
2236 if (dev_id
== table
->dev_id
)
2243 mutex_unlock(&gpio_lookup_lock
);
2247 static struct gpio_desc
*gpiod_find(struct device
*dev
, const char *con_id
,
2249 enum gpio_lookup_flags
*flags
)
2251 struct gpio_desc
*desc
= ERR_PTR(-ENOENT
);
2252 struct gpiod_lookup_table
*table
;
2253 struct gpiod_lookup
*p
;
2255 table
= gpiod_find_lookup_table(dev
);
2259 for (p
= &table
->table
[0]; p
->chip_label
; p
++) {
2260 struct gpio_chip
*chip
;
2262 /* idx must always match exactly */
2266 /* If the lookup entry has a con_id, require exact match */
2267 if (p
->con_id
&& (!con_id
|| strcmp(p
->con_id
, con_id
)))
2270 chip
= find_chip_by_name(p
->chip_label
);
2273 dev_err(dev
, "cannot find GPIO chip %s\n",
2275 return ERR_PTR(-ENODEV
);
2278 if (chip
->ngpio
<= p
->chip_hwnum
) {
2280 "requested GPIO %d is out of range [0..%d] for chip %s\n",
2281 idx
, chip
->ngpio
, chip
->label
);
2282 return ERR_PTR(-EINVAL
);
2285 desc
= gpiochip_get_desc(chip
, p
->chip_hwnum
);
2294 static int dt_gpio_count(struct device
*dev
, const char *con_id
)
2300 for (i
= 0; i
< ARRAY_SIZE(gpio_suffixes
); i
++) {
2302 snprintf(propname
, sizeof(propname
), "%s-%s",
2303 con_id
, gpio_suffixes
[i
]);
2305 snprintf(propname
, sizeof(propname
), "%s",
2308 ret
= of_gpio_named_count(dev
->of_node
, propname
);
2315 static int platform_gpio_count(struct device
*dev
, const char *con_id
)
2317 struct gpiod_lookup_table
*table
;
2318 struct gpiod_lookup
*p
;
2319 unsigned int count
= 0;
2321 table
= gpiod_find_lookup_table(dev
);
2325 for (p
= &table
->table
[0]; p
->chip_label
; p
++) {
2326 if ((con_id
&& p
->con_id
&& !strcmp(con_id
, p
->con_id
)) ||
2327 (!con_id
&& !p
->con_id
))
2337 * gpiod_count - return the number of GPIOs associated with a device / function
2338 * or -ENOENT if no GPIO has been assigned to the requested function
2339 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2340 * @con_id: function within the GPIO consumer
2342 int gpiod_count(struct device
*dev
, const char *con_id
)
2344 int count
= -ENOENT
;
2346 if (IS_ENABLED(CONFIG_OF
) && dev
&& dev
->of_node
)
2347 count
= dt_gpio_count(dev
, con_id
);
2348 else if (IS_ENABLED(CONFIG_ACPI
) && dev
&& ACPI_HANDLE(dev
))
2349 count
= acpi_gpio_count(dev
, con_id
);
2352 count
= platform_gpio_count(dev
, con_id
);
2356 EXPORT_SYMBOL_GPL(gpiod_count
);
2359 * gpiod_get - obtain a GPIO for a given GPIO function
2360 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2361 * @con_id: function within the GPIO consumer
2362 * @flags: optional GPIO initialization flags
2364 * Return the GPIO descriptor corresponding to the function con_id of device
2365 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
2366 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
2368 struct gpio_desc
*__must_check
gpiod_get(struct device
*dev
, const char *con_id
,
2369 enum gpiod_flags flags
)
2371 return gpiod_get_index(dev
, con_id
, 0, flags
);
2373 EXPORT_SYMBOL_GPL(gpiod_get
);
2376 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
2377 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2378 * @con_id: function within the GPIO consumer
2379 * @flags: optional GPIO initialization flags
2381 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
2382 * the requested function it will return NULL. This is convenient for drivers
2383 * that need to handle optional GPIOs.
2385 struct gpio_desc
*__must_check
gpiod_get_optional(struct device
*dev
,
2387 enum gpiod_flags flags
)
2389 return gpiod_get_index_optional(dev
, con_id
, 0, flags
);
2391 EXPORT_SYMBOL_GPL(gpiod_get_optional
);
2394 * gpiod_parse_flags - helper function to parse GPIO lookup flags
2395 * @desc: gpio to be setup
2396 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2399 * Set the GPIO descriptor flags based on the given GPIO lookup flags.
2401 static void gpiod_parse_flags(struct gpio_desc
*desc
, unsigned long lflags
)
2403 if (lflags
& GPIO_ACTIVE_LOW
)
2404 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
2405 if (lflags
& GPIO_OPEN_DRAIN
)
2406 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
2407 if (lflags
& GPIO_OPEN_SOURCE
)
2408 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
2412 * gpiod_configure_flags - helper function to configure a given GPIO
2413 * @desc: gpio whose value will be assigned
2414 * @con_id: function within the GPIO consumer
2415 * @dflags: gpiod_flags - optional GPIO initialization flags
2417 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
2418 * requested function and/or index, or another IS_ERR() code if an error
2419 * occurred while trying to acquire the GPIO.
2421 static int gpiod_configure_flags(struct gpio_desc
*desc
, const char *con_id
,
2422 enum gpiod_flags dflags
)
2426 /* No particular flag request, return here... */
2427 if (!(dflags
& GPIOD_FLAGS_BIT_DIR_SET
)) {
2428 pr_debug("no flags found for %s\n", con_id
);
2433 if (dflags
& GPIOD_FLAGS_BIT_DIR_OUT
)
2434 status
= gpiod_direction_output(desc
,
2435 dflags
& GPIOD_FLAGS_BIT_DIR_VAL
);
2437 status
= gpiod_direction_input(desc
);
2443 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
2444 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2445 * @con_id: function within the GPIO consumer
2446 * @idx: index of the GPIO to obtain in the consumer
2447 * @flags: optional GPIO initialization flags
2449 * This variant of gpiod_get() allows to access GPIOs other than the first
2450 * defined one for functions that define several GPIOs.
2452 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
2453 * requested function and/or index, or another IS_ERR() code if an error
2454 * occurred while trying to acquire the GPIO.
2456 struct gpio_desc
*__must_check
gpiod_get_index(struct device
*dev
,
2459 enum gpiod_flags flags
)
2461 struct gpio_desc
*desc
= NULL
;
2463 enum gpio_lookup_flags lookupflags
= 0;
2465 dev_dbg(dev
, "GPIO lookup for consumer %s\n", con_id
);
2468 /* Using device tree? */
2469 if (IS_ENABLED(CONFIG_OF
) && dev
->of_node
) {
2470 dev_dbg(dev
, "using device tree for GPIO lookup\n");
2471 desc
= of_find_gpio(dev
, con_id
, idx
, &lookupflags
);
2472 } else if (ACPI_COMPANION(dev
)) {
2473 dev_dbg(dev
, "using ACPI for GPIO lookup\n");
2474 desc
= acpi_find_gpio(dev
, con_id
, idx
, &lookupflags
);
2479 * Either we are not using DT or ACPI, or their lookup did not return
2480 * a result. In that case, use platform lookup as a fallback.
2482 if (!desc
|| desc
== ERR_PTR(-ENOENT
)) {
2483 dev_dbg(dev
, "using lookup tables for GPIO lookup\n");
2484 desc
= gpiod_find(dev
, con_id
, idx
, &lookupflags
);
2488 dev_dbg(dev
, "lookup for GPIO %s failed\n", con_id
);
2492 gpiod_parse_flags(desc
, lookupflags
);
2494 status
= gpiod_request(desc
, con_id
);
2496 return ERR_PTR(status
);
2498 status
= gpiod_configure_flags(desc
, con_id
, flags
);
2500 dev_dbg(dev
, "setup of GPIO %s failed\n", con_id
);
2502 return ERR_PTR(status
);
2507 EXPORT_SYMBOL_GPL(gpiod_get_index
);
2510 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
2511 * @fwnode: handle of the firmware node
2512 * @propname: name of the firmware property representing the GPIO
2514 * This function can be used for drivers that get their configuration
2517 * Function properly finds the corresponding GPIO using whatever is the
2518 * underlying firmware interface and then makes sure that the GPIO
2519 * descriptor is requested before it is returned to the caller.
2521 * In case of error an ERR_PTR() is returned.
2523 struct gpio_desc
*fwnode_get_named_gpiod(struct fwnode_handle
*fwnode
,
2524 const char *propname
)
2526 struct gpio_desc
*desc
= ERR_PTR(-ENODEV
);
2527 bool active_low
= false;
2528 bool single_ended
= false;
2532 return ERR_PTR(-EINVAL
);
2534 if (is_of_node(fwnode
)) {
2535 enum of_gpio_flags flags
;
2537 desc
= of_get_named_gpiod_flags(to_of_node(fwnode
), propname
, 0,
2539 if (!IS_ERR(desc
)) {
2540 active_low
= flags
& OF_GPIO_ACTIVE_LOW
;
2541 single_ended
= flags
& OF_GPIO_SINGLE_ENDED
;
2543 } else if (is_acpi_node(fwnode
)) {
2544 struct acpi_gpio_info info
;
2546 desc
= acpi_node_get_gpiod(fwnode
, propname
, 0, &info
);
2548 active_low
= info
.polarity
== GPIO_ACTIVE_LOW
;
2555 set_bit(FLAG_ACTIVE_LOW
, &desc
->flags
);
2559 set_bit(FLAG_OPEN_DRAIN
, &desc
->flags
);
2561 set_bit(FLAG_OPEN_SOURCE
, &desc
->flags
);
2564 ret
= gpiod_request(desc
, NULL
);
2566 return ERR_PTR(ret
);
2570 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod
);
2573 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
2575 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2576 * @con_id: function within the GPIO consumer
2577 * @index: index of the GPIO to obtain in the consumer
2578 * @flags: optional GPIO initialization flags
2580 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
2581 * specified index was assigned to the requested function it will return NULL.
2582 * This is convenient for drivers that need to handle optional GPIOs.
2584 struct gpio_desc
*__must_check
gpiod_get_index_optional(struct device
*dev
,
2587 enum gpiod_flags flags
)
2589 struct gpio_desc
*desc
;
2591 desc
= gpiod_get_index(dev
, con_id
, index
, flags
);
2593 if (PTR_ERR(desc
) == -ENOENT
)
2599 EXPORT_SYMBOL_GPL(gpiod_get_index_optional
);
2602 * gpiod_hog - Hog the specified GPIO desc given the provided flags
2603 * @desc: gpio whose value will be assigned
2604 * @name: gpio line name
2605 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
2607 * @dflags: gpiod_flags - optional GPIO initialization flags
2609 int gpiod_hog(struct gpio_desc
*desc
, const char *name
,
2610 unsigned long lflags
, enum gpiod_flags dflags
)
2612 struct gpio_chip
*chip
;
2613 struct gpio_desc
*local_desc
;
2617 chip
= gpiod_to_chip(desc
);
2618 hwnum
= gpio_chip_hwgpio(desc
);
2620 gpiod_parse_flags(desc
, lflags
);
2622 local_desc
= gpiochip_request_own_desc(chip
, hwnum
, name
);
2623 if (IS_ERR(local_desc
)) {
2624 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed\n",
2625 name
, chip
->label
, hwnum
);
2626 return PTR_ERR(local_desc
);
2629 status
= gpiod_configure_flags(desc
, name
, dflags
);
2631 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed\n",
2632 name
, chip
->label
, hwnum
);
2633 gpiochip_free_own_desc(desc
);
2637 /* Mark GPIO as hogged so it can be identified and removed later */
2638 set_bit(FLAG_IS_HOGGED
, &desc
->flags
);
2640 pr_info("GPIO line %d (%s) hogged as %s%s\n",
2641 desc_to_gpio(desc
), name
,
2642 (dflags
&GPIOD_FLAGS_BIT_DIR_OUT
) ? "output" : "input",
2643 (dflags
&GPIOD_FLAGS_BIT_DIR_OUT
) ?
2644 (dflags
&GPIOD_FLAGS_BIT_DIR_VAL
) ? "/high" : "/low":"");
2650 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
2651 * @chip: gpio chip to act on
2653 * This is only used by of_gpiochip_remove to free hogged gpios
2655 static void gpiochip_free_hogs(struct gpio_chip
*chip
)
2659 for (id
= 0; id
< chip
->ngpio
; id
++) {
2660 if (test_bit(FLAG_IS_HOGGED
, &chip
->gpiodev
->descs
[id
].flags
))
2661 gpiochip_free_own_desc(&chip
->gpiodev
->descs
[id
]);
2666 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
2667 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2668 * @con_id: function within the GPIO consumer
2669 * @flags: optional GPIO initialization flags
2671 * This function acquires all the GPIOs defined under a given function.
2673 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
2674 * no GPIO has been assigned to the requested function, or another IS_ERR()
2675 * code if an error occurred while trying to acquire the GPIOs.
2677 struct gpio_descs
*__must_check
gpiod_get_array(struct device
*dev
,
2679 enum gpiod_flags flags
)
2681 struct gpio_desc
*desc
;
2682 struct gpio_descs
*descs
;
2685 count
= gpiod_count(dev
, con_id
);
2687 return ERR_PTR(count
);
2689 descs
= kzalloc(sizeof(*descs
) + sizeof(descs
->desc
[0]) * count
,
2692 return ERR_PTR(-ENOMEM
);
2694 for (descs
->ndescs
= 0; descs
->ndescs
< count
; ) {
2695 desc
= gpiod_get_index(dev
, con_id
, descs
->ndescs
, flags
);
2697 gpiod_put_array(descs
);
2698 return ERR_CAST(desc
);
2700 descs
->desc
[descs
->ndescs
] = desc
;
2705 EXPORT_SYMBOL_GPL(gpiod_get_array
);
2708 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
2710 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2711 * @con_id: function within the GPIO consumer
2712 * @flags: optional GPIO initialization flags
2714 * This is equivalent to gpiod_get_array(), except that when no GPIO was
2715 * assigned to the requested function it will return NULL.
2717 struct gpio_descs
*__must_check
gpiod_get_array_optional(struct device
*dev
,
2719 enum gpiod_flags flags
)
2721 struct gpio_descs
*descs
;
2723 descs
= gpiod_get_array(dev
, con_id
, flags
);
2724 if (IS_ERR(descs
) && (PTR_ERR(descs
) == -ENOENT
))
2729 EXPORT_SYMBOL_GPL(gpiod_get_array_optional
);
2732 * gpiod_put - dispose of a GPIO descriptor
2733 * @desc: GPIO descriptor to dispose of
2735 * No descriptor can be used after gpiod_put() has been called on it.
2737 void gpiod_put(struct gpio_desc
*desc
)
2741 EXPORT_SYMBOL_GPL(gpiod_put
);
2744 * gpiod_put_array - dispose of multiple GPIO descriptors
2745 * @descs: struct gpio_descs containing an array of descriptors
2747 void gpiod_put_array(struct gpio_descs
*descs
)
2751 for (i
= 0; i
< descs
->ndescs
; i
++)
2752 gpiod_put(descs
->desc
[i
]);
2756 EXPORT_SYMBOL_GPL(gpiod_put_array
);
2758 static int __init
gpiolib_dev_init(void)
2762 /* Register GPIO sysfs bus */
2763 ret
= bus_register(&gpio_bus_type
);
2765 pr_err("gpiolib: could not register GPIO bus type\n");
2769 ret
= alloc_chrdev_region(&gpio_devt
, 0, GPIO_DEV_MAX
, "gpiochip");
2771 pr_err("gpiolib: failed to allocate char dev region\n");
2772 bus_unregister(&gpio_bus_type
);
2776 core_initcall(gpiolib_dev_init
);
2778 #ifdef CONFIG_DEBUG_FS
2780 static void gpiolib_dbg_show(struct seq_file
*s
, struct gpio_device
*gdev
)
2783 struct gpio_chip
*chip
= gdev
->chip
;
2784 unsigned gpio
= gdev
->base
;
2785 struct gpio_desc
*gdesc
= &gdev
->descs
[0];
2789 for (i
= 0; i
< gdev
->ngpio
; i
++, gpio
++, gdesc
++) {
2790 if (!test_bit(FLAG_REQUESTED
, &gdesc
->flags
)) {
2792 seq_printf(s
, " gpio-%-3d (%-20.20s)\n",
2798 gpiod_get_direction(gdesc
);
2799 is_out
= test_bit(FLAG_IS_OUT
, &gdesc
->flags
);
2800 is_irq
= test_bit(FLAG_USED_AS_IRQ
, &gdesc
->flags
);
2801 seq_printf(s
, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
2802 gpio
, gdesc
->name
? gdesc
->name
: "", gdesc
->label
,
2803 is_out
? "out" : "in ",
2805 ? (chip
->get(chip
, i
) ? "hi" : "lo")
2807 is_irq
? "IRQ" : " ");
2808 seq_printf(s
, "\n");
2812 static void *gpiolib_seq_start(struct seq_file
*s
, loff_t
*pos
)
2814 unsigned long flags
;
2815 struct gpio_device
*gdev
= NULL
;
2816 loff_t index
= *pos
;
2820 spin_lock_irqsave(&gpio_lock
, flags
);
2821 list_for_each_entry(gdev
, &gpio_devices
, list
)
2823 spin_unlock_irqrestore(&gpio_lock
, flags
);
2826 spin_unlock_irqrestore(&gpio_lock
, flags
);
2831 static void *gpiolib_seq_next(struct seq_file
*s
, void *v
, loff_t
*pos
)
2833 unsigned long flags
;
2834 struct gpio_device
*gdev
= v
;
2837 spin_lock_irqsave(&gpio_lock
, flags
);
2838 if (list_is_last(&gdev
->list
, &gpio_devices
))
2841 ret
= list_entry(gdev
->list
.next
, struct gpio_device
, list
);
2842 spin_unlock_irqrestore(&gpio_lock
, flags
);
2850 static void gpiolib_seq_stop(struct seq_file
*s
, void *v
)
2854 static int gpiolib_seq_show(struct seq_file
*s
, void *v
)
2856 struct gpio_device
*gdev
= v
;
2857 struct gpio_chip
*chip
= gdev
->chip
;
2858 struct device
*parent
;
2861 seq_printf(s
, "%s%s: (dangling chip)", (char *)s
->private,
2862 dev_name(&gdev
->dev
));
2866 seq_printf(s
, "%s%s: GPIOs %d-%d", (char *)s
->private,
2867 dev_name(&gdev
->dev
),
2868 gdev
->base
, gdev
->base
+ gdev
->ngpio
- 1);
2869 parent
= chip
->parent
;
2871 seq_printf(s
, ", parent: %s/%s",
2872 parent
->bus
? parent
->bus
->name
: "no-bus",
2875 seq_printf(s
, ", %s", chip
->label
);
2876 if (chip
->can_sleep
)
2877 seq_printf(s
, ", can sleep");
2878 seq_printf(s
, ":\n");
2881 chip
->dbg_show(s
, chip
);
2883 gpiolib_dbg_show(s
, gdev
);
2888 static const struct seq_operations gpiolib_seq_ops
= {
2889 .start
= gpiolib_seq_start
,
2890 .next
= gpiolib_seq_next
,
2891 .stop
= gpiolib_seq_stop
,
2892 .show
= gpiolib_seq_show
,
2895 static int gpiolib_open(struct inode
*inode
, struct file
*file
)
2897 return seq_open(file
, &gpiolib_seq_ops
);
2900 static const struct file_operations gpiolib_operations
= {
2901 .owner
= THIS_MODULE
,
2902 .open
= gpiolib_open
,
2904 .llseek
= seq_lseek
,
2905 .release
= seq_release
,
2908 static int __init
gpiolib_debugfs_init(void)
2910 /* /sys/kernel/debug/gpio */
2911 (void) debugfs_create_file("gpio", S_IFREG
| S_IRUGO
,
2912 NULL
, NULL
, &gpiolib_operations
);
2915 subsys_initcall(gpiolib_debugfs_init
);
2917 #endif /* DEBUG_FS */