2 * ACPI helpers for GPIO API
4 * Copyright (C) 2012, Intel Corporation
5 * Authors: Mathias Nyman <mathias.nyman@linux.intel.com>
6 * Mika Westerberg <mika.westerberg@linux.intel.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/errno.h>
14 #include <linux/gpio.h>
15 #include <linux/gpio/consumer.h>
16 #include <linux/gpio/driver.h>
17 #include <linux/export.h>
18 #include <linux/acpi.h>
19 #include <linux/interrupt.h>
20 #include <linux/mutex.h>
21 #include <linux/pinctrl/pinctrl.h>
25 struct acpi_gpio_event
{
26 struct list_head node
;
30 struct gpio_desc
*desc
;
33 struct acpi_gpio_connection
{
34 struct list_head node
;
36 struct gpio_desc
*desc
;
39 struct acpi_gpio_chip
{
41 * ACPICA requires that the first field of the context parameter
42 * passed to acpi_install_address_space_handler() is large enough
43 * to hold struct acpi_connection_info.
45 struct acpi_connection_info conn_info
;
46 struct list_head conns
;
47 struct mutex conn_lock
;
48 struct gpio_chip
*chip
;
49 struct list_head events
;
52 static int acpi_gpiochip_find(struct gpio_chip
*gc
, void *data
)
57 return ACPI_HANDLE(gc
->dev
) == data
;
62 * acpi_gpiochip_pin_to_gpio_offset() - translates ACPI GPIO to Linux GPIO
64 * @pin: ACPI GPIO pin number from GpioIo/GpioInt resource
66 * Function takes ACPI GpioIo/GpioInt pin number as a parameter and
67 * translates it to a corresponding offset suitable to be passed to a
68 * GPIO controller driver.
70 * Typically the returned offset is same as @pin, but if the GPIO
71 * controller uses pin controller and the mapping is not contigous the
72 * offset might be different.
74 static int acpi_gpiochip_pin_to_gpio_offset(struct gpio_chip
*chip
, int pin
)
76 struct gpio_pin_range
*pin_range
;
78 /* If there are no ranges in this chip, use 1:1 mapping */
79 if (list_empty(&chip
->pin_ranges
))
82 list_for_each_entry(pin_range
, &chip
->pin_ranges
, node
) {
83 const struct pinctrl_gpio_range
*range
= &pin_range
->range
;
87 for (i
= 0; i
< range
->npins
; i
++) {
88 if (range
->pins
[i
] == pin
)
89 return range
->base
+ i
- chip
->base
;
92 if (pin
>= range
->pin_base
&&
93 pin
< range
->pin_base
+ range
->npins
) {
96 gpio_base
= range
->base
- chip
->base
;
97 return gpio_base
+ pin
- range
->pin_base
;
105 static inline int acpi_gpiochip_pin_to_gpio_offset(struct gpio_chip
*chip
,
113 * acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with GPIO API
114 * @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
115 * @pin: ACPI GPIO pin number (0-based, controller-relative)
117 * Returns GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR
121 static struct gpio_desc
*acpi_get_gpiod(char *path
, int pin
)
123 struct gpio_chip
*chip
;
128 status
= acpi_get_handle(NULL
, path
, &handle
);
129 if (ACPI_FAILURE(status
))
130 return ERR_PTR(-ENODEV
);
132 chip
= gpiochip_find(handle
, acpi_gpiochip_find
);
134 return ERR_PTR(-ENODEV
);
136 offset
= acpi_gpiochip_pin_to_gpio_offset(chip
, pin
);
138 return ERR_PTR(offset
);
140 return gpiochip_get_desc(chip
, offset
);
143 static irqreturn_t
acpi_gpio_irq_handler(int irq
, void *data
)
145 struct acpi_gpio_event
*event
= data
;
147 acpi_evaluate_object(event
->handle
, NULL
, NULL
, NULL
);
152 static irqreturn_t
acpi_gpio_irq_handler_evt(int irq
, void *data
)
154 struct acpi_gpio_event
*event
= data
;
156 acpi_execute_simple_method(event
->handle
, NULL
, event
->pin
);
161 static void acpi_gpio_chip_dh(acpi_handle handle
, void *data
)
163 /* The address of this function is used as a key. */
166 static acpi_status
acpi_gpiochip_request_interrupt(struct acpi_resource
*ares
,
169 struct acpi_gpio_chip
*acpi_gpio
= context
;
170 struct gpio_chip
*chip
= acpi_gpio
->chip
;
171 struct acpi_resource_gpio
*agpio
;
172 acpi_handle handle
, evt_handle
;
173 struct acpi_gpio_event
*event
;
174 irq_handler_t handler
= NULL
;
175 struct gpio_desc
*desc
;
176 unsigned long irqflags
;
179 if (ares
->type
!= ACPI_RESOURCE_TYPE_GPIO
)
182 agpio
= &ares
->data
.gpio
;
183 if (agpio
->connection_type
!= ACPI_RESOURCE_GPIO_TYPE_INT
)
186 handle
= ACPI_HANDLE(chip
->dev
);
187 pin
= agpio
->pin_table
[0];
191 sprintf(ev_name
, "_%c%02X",
192 agpio
->triggering
== ACPI_EDGE_SENSITIVE
? 'E' : 'L',
194 if (ACPI_SUCCESS(acpi_get_handle(handle
, ev_name
, &evt_handle
)))
195 handler
= acpi_gpio_irq_handler
;
198 if (ACPI_SUCCESS(acpi_get_handle(handle
, "_EVT", &evt_handle
)))
199 handler
= acpi_gpio_irq_handler_evt
;
202 return AE_BAD_PARAMETER
;
204 desc
= gpiochip_request_own_desc(chip
, pin
, "ACPI:Event");
206 dev_err(chip
->dev
, "Failed to request GPIO\n");
210 gpiod_direction_input(desc
);
212 ret
= gpiochip_lock_as_irq(chip
, pin
);
214 dev_err(chip
->dev
, "Failed to lock GPIO as interrupt\n");
218 irq
= gpiod_to_irq(desc
);
220 dev_err(chip
->dev
, "Failed to translate GPIO to IRQ\n");
221 goto fail_unlock_irq
;
224 irqflags
= IRQF_ONESHOT
;
225 if (agpio
->triggering
== ACPI_LEVEL_SENSITIVE
) {
226 if (agpio
->polarity
== ACPI_ACTIVE_HIGH
)
227 irqflags
|= IRQF_TRIGGER_HIGH
;
229 irqflags
|= IRQF_TRIGGER_LOW
;
231 switch (agpio
->polarity
) {
232 case ACPI_ACTIVE_HIGH
:
233 irqflags
|= IRQF_TRIGGER_RISING
;
235 case ACPI_ACTIVE_LOW
:
236 irqflags
|= IRQF_TRIGGER_FALLING
;
239 irqflags
|= IRQF_TRIGGER_RISING
|
240 IRQF_TRIGGER_FALLING
;
245 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
247 goto fail_unlock_irq
;
249 event
->handle
= evt_handle
;
254 ret
= request_threaded_irq(event
->irq
, NULL
, handler
, irqflags
,
255 "ACPI:Event", event
);
257 dev_err(chip
->dev
, "Failed to setup interrupt handler for %d\n",
259 goto fail_free_event
;
262 list_add_tail(&event
->node
, &acpi_gpio
->events
);
268 gpiochip_unlock_as_irq(chip
, pin
);
270 gpiochip_free_own_desc(desc
);
276 * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
279 * ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
280 * handled by ACPI event methods which need to be called from the GPIO
281 * chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
282 * gpio pins have acpi event methods and assigns interrupt handlers that calls
283 * the acpi event methods for those pins.
285 void acpi_gpiochip_request_interrupts(struct gpio_chip
*chip
)
287 struct acpi_gpio_chip
*acpi_gpio
;
291 if (!chip
->dev
|| !chip
->to_irq
)
294 handle
= ACPI_HANDLE(chip
->dev
);
298 status
= acpi_get_data(handle
, acpi_gpio_chip_dh
, (void **)&acpi_gpio
);
299 if (ACPI_FAILURE(status
))
302 INIT_LIST_HEAD(&acpi_gpio
->events
);
303 acpi_walk_resources(ACPI_HANDLE(chip
->dev
), "_AEI",
304 acpi_gpiochip_request_interrupt
, acpi_gpio
);
308 * acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
311 * Free interrupts associated with GPIO ACPI event method for the given
314 void acpi_gpiochip_free_interrupts(struct gpio_chip
*chip
)
316 struct acpi_gpio_chip
*acpi_gpio
;
317 struct acpi_gpio_event
*event
, *ep
;
321 if (!chip
->dev
|| !chip
->to_irq
)
324 handle
= ACPI_HANDLE(chip
->dev
);
328 status
= acpi_get_data(handle
, acpi_gpio_chip_dh
, (void **)&acpi_gpio
);
329 if (ACPI_FAILURE(status
))
332 list_for_each_entry_safe_reverse(event
, ep
, &acpi_gpio
->events
, node
) {
333 struct gpio_desc
*desc
;
335 free_irq(event
->irq
, event
);
337 if (WARN_ON(IS_ERR(desc
)))
339 gpiochip_unlock_as_irq(chip
, event
->pin
);
340 gpiochip_free_own_desc(desc
);
341 list_del(&event
->node
);
346 int acpi_dev_add_driver_gpios(struct acpi_device
*adev
,
347 const struct acpi_gpio_mapping
*gpios
)
350 adev
->driver_gpios
= gpios
;
355 EXPORT_SYMBOL_GPL(acpi_dev_add_driver_gpios
);
357 static bool acpi_get_driver_gpio_data(struct acpi_device
*adev
,
358 const char *name
, int index
,
359 struct acpi_reference_args
*args
)
361 const struct acpi_gpio_mapping
*gm
;
363 if (!adev
->driver_gpios
)
366 for (gm
= adev
->driver_gpios
; gm
->name
; gm
++)
367 if (!strcmp(name
, gm
->name
) && gm
->data
&& index
< gm
->size
) {
368 const struct acpi_gpio_params
*par
= gm
->data
+ index
;
371 args
->args
[0] = par
->crs_entry_index
;
372 args
->args
[1] = par
->line_index
;
373 args
->args
[2] = par
->active_low
;
381 struct acpi_gpio_lookup
{
382 struct acpi_gpio_info info
;
385 struct gpio_desc
*desc
;
389 static int acpi_find_gpio(struct acpi_resource
*ares
, void *data
)
391 struct acpi_gpio_lookup
*lookup
= data
;
393 if (ares
->type
!= ACPI_RESOURCE_TYPE_GPIO
)
396 if (lookup
->n
++ == lookup
->index
&& !lookup
->desc
) {
397 const struct acpi_resource_gpio
*agpio
= &ares
->data
.gpio
;
398 int pin_index
= lookup
->pin_index
;
400 if (pin_index
>= agpio
->pin_table_length
)
403 lookup
->desc
= acpi_get_gpiod(agpio
->resource_source
.string_ptr
,
404 agpio
->pin_table
[pin_index
]);
405 lookup
->info
.gpioint
=
406 agpio
->connection_type
== ACPI_RESOURCE_GPIO_TYPE_INT
;
409 * ActiveLow is only specified for GpioInt resource. If
410 * GpioIo is used then the only way to set the flag is
411 * to use _DSD "gpios" property.
413 if (lookup
->info
.gpioint
)
414 lookup
->info
.active_low
=
415 agpio
->polarity
== ACPI_ACTIVE_LOW
;
422 * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
423 * @adev: pointer to a ACPI device to get GPIO from
424 * @propname: Property name of the GPIO (optional)
425 * @index: index of GpioIo/GpioInt resource (starting from %0)
426 * @info: info pointer to fill in (optional)
428 * Function goes through ACPI resources for @adev and based on @index looks
429 * up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
430 * and returns it. @index matches GpioIo/GpioInt resources only so if there
431 * are total %3 GPIO resources, the index goes from %0 to %2.
433 * If @propname is specified the GPIO is looked using device property. In
434 * that case @index is used to select the GPIO entry in the property value
435 * (in case of multiple).
437 * If the GPIO cannot be translated or there is an error an ERR_PTR is
440 * Note: if the GPIO resource has multiple entries in the pin list, this
441 * function only returns the first.
443 struct gpio_desc
*acpi_get_gpiod_by_index(struct acpi_device
*adev
,
444 const char *propname
, int index
,
445 struct acpi_gpio_info
*info
)
447 struct acpi_gpio_lookup lookup
;
448 struct list_head resource_list
;
449 bool active_low
= false;
453 return ERR_PTR(-ENODEV
);
455 memset(&lookup
, 0, sizeof(lookup
));
456 lookup
.index
= index
;
459 struct acpi_reference_args args
;
461 dev_dbg(&adev
->dev
, "GPIO: looking up %s\n", propname
);
463 memset(&args
, 0, sizeof(args
));
464 ret
= acpi_dev_get_property_reference(adev
, propname
,
467 bool found
= acpi_get_driver_gpio_data(adev
, propname
,
474 * The property was found and resolved so need to
475 * lookup the GPIO based on returned args instead.
478 if (args
.nargs
>= 2) {
479 lookup
.index
= args
.args
[0];
480 lookup
.pin_index
= args
.args
[1];
482 * 3rd argument, if present is used to
483 * specify active_low.
486 active_low
= !!args
.args
[2];
489 dev_dbg(&adev
->dev
, "GPIO: _DSD returned %s %zd %llu %llu %llu\n",
490 dev_name(&adev
->dev
), args
.nargs
,
491 args
.args
[0], args
.args
[1], args
.args
[2]);
493 dev_dbg(&adev
->dev
, "GPIO: looking up %d in _CRS\n", index
);
496 INIT_LIST_HEAD(&resource_list
);
497 ret
= acpi_dev_get_resources(adev
, &resource_list
, acpi_find_gpio
,
502 acpi_dev_free_resource_list(&resource_list
);
504 if (lookup
.desc
&& info
) {
507 info
->active_low
= active_low
;
510 return lookup
.desc
? lookup
.desc
: ERR_PTR(-ENOENT
);
514 acpi_gpio_adr_space_handler(u32 function
, acpi_physical_address address
,
515 u32 bits
, u64
*value
, void *handler_context
,
516 void *region_context
)
518 struct acpi_gpio_chip
*achip
= region_context
;
519 struct gpio_chip
*chip
= achip
->chip
;
520 struct acpi_resource_gpio
*agpio
;
521 struct acpi_resource
*ares
;
522 int pin_index
= (int)address
;
528 status
= acpi_buffer_to_resource(achip
->conn_info
.connection
,
529 achip
->conn_info
.length
, &ares
);
530 if (ACPI_FAILURE(status
))
533 if (WARN_ON(ares
->type
!= ACPI_RESOURCE_TYPE_GPIO
)) {
535 return AE_BAD_PARAMETER
;
538 agpio
= &ares
->data
.gpio
;
539 pull_up
= agpio
->pin_config
== ACPI_PIN_CONFIG_PULLUP
;
541 if (WARN_ON(agpio
->io_restriction
== ACPI_IO_RESTRICT_INPUT
&&
542 function
== ACPI_WRITE
)) {
544 return AE_BAD_PARAMETER
;
547 length
= min(agpio
->pin_table_length
, (u16
)(pin_index
+ bits
));
548 for (i
= pin_index
; i
< length
; ++i
) {
549 unsigned pin
= agpio
->pin_table
[i
];
550 struct acpi_gpio_connection
*conn
;
551 struct gpio_desc
*desc
;
554 mutex_lock(&achip
->conn_lock
);
557 list_for_each_entry(conn
, &achip
->conns
, node
) {
558 if (conn
->pin
== pin
) {
565 desc
= gpiochip_request_own_desc(chip
, pin
,
569 mutex_unlock(&achip
->conn_lock
);
573 switch (agpio
->io_restriction
) {
574 case ACPI_IO_RESTRICT_INPUT
:
575 gpiod_direction_input(desc
);
577 case ACPI_IO_RESTRICT_OUTPUT
:
579 * ACPI GPIO resources don't contain an
580 * initial value for the GPIO. Therefore we
581 * deduce that value from the pull field
582 * instead. If the pin is pulled up we
583 * assume default to be high, otherwise
586 gpiod_direction_output(desc
, pull_up
);
590 * Assume that the BIOS has configured the
591 * direction and pull accordingly.
596 conn
= kzalloc(sizeof(*conn
), GFP_KERNEL
);
598 status
= AE_NO_MEMORY
;
599 gpiochip_free_own_desc(desc
);
600 mutex_unlock(&achip
->conn_lock
);
606 list_add_tail(&conn
->node
, &achip
->conns
);
609 mutex_unlock(&achip
->conn_lock
);
611 if (function
== ACPI_WRITE
)
612 gpiod_set_raw_value_cansleep(desc
,
613 !!((1 << i
) & *value
));
615 *value
|= (u64
)gpiod_get_raw_value_cansleep(desc
) << i
;
623 static void acpi_gpiochip_request_regions(struct acpi_gpio_chip
*achip
)
625 struct gpio_chip
*chip
= achip
->chip
;
626 acpi_handle handle
= ACPI_HANDLE(chip
->dev
);
629 INIT_LIST_HEAD(&achip
->conns
);
630 mutex_init(&achip
->conn_lock
);
631 status
= acpi_install_address_space_handler(handle
, ACPI_ADR_SPACE_GPIO
,
632 acpi_gpio_adr_space_handler
,
634 if (ACPI_FAILURE(status
))
635 dev_err(chip
->dev
, "Failed to install GPIO OpRegion handler\n");
638 static void acpi_gpiochip_free_regions(struct acpi_gpio_chip
*achip
)
640 struct gpio_chip
*chip
= achip
->chip
;
641 acpi_handle handle
= ACPI_HANDLE(chip
->dev
);
642 struct acpi_gpio_connection
*conn
, *tmp
;
645 status
= acpi_remove_address_space_handler(handle
, ACPI_ADR_SPACE_GPIO
,
646 acpi_gpio_adr_space_handler
);
647 if (ACPI_FAILURE(status
)) {
648 dev_err(chip
->dev
, "Failed to remove GPIO OpRegion handler\n");
652 list_for_each_entry_safe_reverse(conn
, tmp
, &achip
->conns
, node
) {
653 gpiochip_free_own_desc(conn
->desc
);
654 list_del(&conn
->node
);
659 void acpi_gpiochip_add(struct gpio_chip
*chip
)
661 struct acpi_gpio_chip
*acpi_gpio
;
665 if (!chip
|| !chip
->dev
)
668 handle
= ACPI_HANDLE(chip
->dev
);
672 acpi_gpio
= kzalloc(sizeof(*acpi_gpio
), GFP_KERNEL
);
675 "Failed to allocate memory for ACPI GPIO chip\n");
679 acpi_gpio
->chip
= chip
;
681 status
= acpi_attach_data(handle
, acpi_gpio_chip_dh
, acpi_gpio
);
682 if (ACPI_FAILURE(status
)) {
683 dev_err(chip
->dev
, "Failed to attach ACPI GPIO chip\n");
688 acpi_gpiochip_request_regions(acpi_gpio
);
691 void acpi_gpiochip_remove(struct gpio_chip
*chip
)
693 struct acpi_gpio_chip
*acpi_gpio
;
697 if (!chip
|| !chip
->dev
)
700 handle
= ACPI_HANDLE(chip
->dev
);
704 status
= acpi_get_data(handle
, acpi_gpio_chip_dh
, (void **)&acpi_gpio
);
705 if (ACPI_FAILURE(status
)) {
706 dev_warn(chip
->dev
, "Failed to retrieve ACPI GPIO chip\n");
710 acpi_gpiochip_free_regions(acpi_gpio
);
712 acpi_detach_data(handle
, acpi_gpio_chip_dh
);