linux/drivers/gpio/gpiolib-acpi.c
Linus Torvalds 58cf279aca GPIO bulk updates for the v4.5 kernel cycle:
Infrastructural changes:
 
 - In struct gpio_chip, rename the .dev node to .parent to better reflect
   the fact that this is not the GPIO struct device abstraction. We will
   add that soon so this would be totallt confusing.
 
 - It was noted that the driver .get_value() callbacks was
   sometimes reporting negative -ERR values to the gpiolib core, expecting
   them to be propagated to consumer gpiod_get_value() and gpio_get_value()
   calls. This was not happening, so as there was a mess of drivers
   returning negative errors and some returning "anything else than zero"
   to indicate that a line was active. As some would have bit 31 set to
   indicate "line active" it clashed with negative error codes. This is
   fixed by the largeish series clamping values in all drivers with
   !!value to [0,1] and then augmenting the code to propagate error codes
   to consumers. (Includes some ACKed patches in other subsystems.)
 
 - Add a void *data pointer to struct gpio_chip. The container_of() design
   pattern is indeed very nice, but we want to reform the struct gpio_chip
   to be a non-volative, stateless business, and keep states internal to
   the gpiolib to be able to hold on to the state when adding a proper
   userspace ABI (character device) further down the road. To achieve this,
   drivers need a handle at the internal state that is not dependent on
   their struct gpio_chip() so we add gpiochip_add_data() and
   gpiochip_get_data() following the pattern of many other subsystems.
   All the "use gpiochip data pointer" patches transforms drivers to this
   scheme.
 
 - The Generic GPIO chip header has been merged into the general
   <linux/gpio/driver.h> header, and the custom header for that removed.
   Instead of having a separate mm_gpio_chip struct for these generic
   drivers, merge that into struct gpio_chip, simplifying the code and
   removing the need for separate and confusing includes.
 
 Misc improvements:
 
 - Stabilize the way GPIOs are looked up from the ACPI legacy
   specification.
 
 - Incremental driver features for PXA, PCA953X, Lantiq (patches from the
   OpenWRT community), RCAR, Zynq, PL061, 104-idi-48
 
 New drivers:
 
 - Add a GPIO chip to the ALSA SoC AC97 driver.
 
 - Add a new Broadcom NSP SoC driver (this lands in the pinctrl dir, but
   the branch is merged here too to account for infrastructural changes).
 
 - The sx150x driver now supports the sx1502.
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Merge tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "Here is the bulk of GPIO changes for v4.5.

  Notably there are big refactorings mostly by myself, aimed at getting
  the gpio_chip into a shape that makes me believe I can proceed to
  preserve state for a proper userspace ABI (character device) that has
  already been proposed once, but resulted in the feedback that I need
  to go back and restructure stuff.  So I've been restructuring stuff.
  On the way I ran into brokenness (return code from the get_value()
  callback) and had to fix it.  Also, refactored generic GPIO to be
  simpler.

  Some of that is still waiting to trickle down from the subsystems all
  over the kernel that provide random gpio_chips, I've touched every
  single GPIO driver in the kernel now, oh man I didn't know I was
  responsible for so much...

  Apart from that we're churning along as usual.

  I took some effort to test and retest so it should merge nicely and we
  shook out a couple of bugs in -next.

  Infrastructural changes:

   - In struct gpio_chip, rename the .dev node to .parent to better
     reflect the fact that this is not the GPIO struct device
     abstraction.  We will add that soon so this would be totallt
     confusing.

   - It was noted that the driver .get_value() callbacks was sometimes
     reporting negative -ERR values to the gpiolib core, expecting them
     to be propagated to consumer gpiod_get_value() and gpio_get_value()
     calls.  This was not happening, so as there was a mess of drivers
     returning negative errors and some returning "anything else than
     zero" to indicate that a line was active.  As some would have bit
     31 set to indicate "line active" it clashed with negative error
     codes.  This is fixed by the largeish series clamping values in all
     drivers with !!value to [0,1] and then augmenting the code to
     propagate error codes to consumers.  (Includes some ACKed patches
     in other subsystems.)

   - Add a void *data pointer to struct gpio_chip.  The container_of()
     design pattern is indeed very nice, but we want to reform the
     struct gpio_chip to be a non-volative, stateless business, and keep
     states internal to the gpiolib to be able to hold on to the state
     when adding a proper userspace ABI (character device) further down
     the road.  To achieve this, drivers need a handle at the internal
     state that is not dependent on their struct gpio_chip() so we add
     gpiochip_add_data() and gpiochip_get_data() following the pattern
     of many other subsystems.  All the "use gpiochip data pointer"
     patches transforms drivers to this scheme.

   - The Generic GPIO chip header has been merged into the general
     <linux/gpio/driver.h> header, and the custom header for that
     removed.  Instead of having a separate mm_gpio_chip struct for
     these generic drivers, merge that into struct gpio_chip,
     simplifying the code and removing the need for separate and
     confusing includes.

  Misc improvements:

   - Stabilize the way GPIOs are looked up from the ACPI legacy
     specification.

   - Incremental driver features for PXA, PCA953X, Lantiq (patches from
     the OpenWRT community), RCAR, Zynq, PL061, 104-idi-48

  New drivers:

   - Add a GPIO chip to the ALSA SoC AC97 driver.

   - Add a new Broadcom NSP SoC driver (this lands in the pinctrl dir,
     but the branch is merged here too to account for infrastructural
     changes).

   - The sx150x driver now supports the sx1502"

* tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (220 commits)
  gpio: generic: make bgpio_pdata always visible
  gpiolib: fix chip order in gpio list
  gpio: mpc8xxx: Do not use gpiochip_get_data() in mpc8xxx_gpio_save_regs()
  gpio: mm-lantiq: Do not use gpiochip_get_data() in ltq_mm_save_regs()
  gpio: brcmstb: Allow building driver for BMIPS_GENERIC
  gpio: brcmstb: Set endian flags for big-endian MIPS
  gpio: moxart: fix build regression
  gpio: xilinx: Do not use gpiochip_get_data() in xgpio_save_regs()
  leds: pca9532: use gpiochip data pointer
  leds: tca6507: use gpiochip data pointer
  hid: cp2112: use gpiochip data pointer
  bcma: gpio: use gpiochip data pointer
  avr32: gpio: use gpiochip data pointer
  video: fbdev: via: use gpiochip data pointer
  gpio: pch: Optimize pch_gpio_get()
  Revert "pinctrl: lantiq: Implement gpio_chip.to_irq"
  pinctrl: nsp-gpio: use gpiochip data pointer
  pinctrl: vt8500-wmt: use gpiochip data pointer
  pinctrl: exynos5440: use gpiochip data pointer
  pinctrl: at91-pio4: use gpiochip data pointer
  ...
2016-01-17 12:32:01 -08:00

992 lines
24 KiB
C

/*
* ACPI helpers for GPIO API
*
* Copyright (C) 2012, Intel Corporation
* Authors: Mathias Nyman <mathias.nyman@linux.intel.com>
* Mika Westerberg <mika.westerberg@linux.intel.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/errno.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/driver.h>
#include <linux/export.h>
#include <linux/acpi.h>
#include <linux/interrupt.h>
#include <linux/mutex.h>
#include <linux/pinctrl/pinctrl.h>
#include "gpiolib.h"
struct acpi_gpio_event {
struct list_head node;
acpi_handle handle;
unsigned int pin;
unsigned int irq;
struct gpio_desc *desc;
};
struct acpi_gpio_connection {
struct list_head node;
unsigned int pin;
struct gpio_desc *desc;
};
struct acpi_gpio_chip {
/*
* ACPICA requires that the first field of the context parameter
* passed to acpi_install_address_space_handler() is large enough
* to hold struct acpi_connection_info.
*/
struct acpi_connection_info conn_info;
struct list_head conns;
struct mutex conn_lock;
struct gpio_chip *chip;
struct list_head events;
};
static int acpi_gpiochip_find(struct gpio_chip *gc, void *data)
{
if (!gc->parent)
return false;
return ACPI_HANDLE(gc->parent) == data;
}
#ifdef CONFIG_PINCTRL
/**
* acpi_gpiochip_pin_to_gpio_offset() - translates ACPI GPIO to Linux GPIO
* @chip: GPIO chip
* @pin: ACPI GPIO pin number from GpioIo/GpioInt resource
*
* Function takes ACPI GpioIo/GpioInt pin number as a parameter and
* translates it to a corresponding offset suitable to be passed to a
* GPIO controller driver.
*
* Typically the returned offset is same as @pin, but if the GPIO
* controller uses pin controller and the mapping is not contiguous the
* offset might be different.
*/
static int acpi_gpiochip_pin_to_gpio_offset(struct gpio_chip *chip, int pin)
{
struct gpio_pin_range *pin_range;
/* If there are no ranges in this chip, use 1:1 mapping */
if (list_empty(&chip->pin_ranges))
return pin;
list_for_each_entry(pin_range, &chip->pin_ranges, node) {
const struct pinctrl_gpio_range *range = &pin_range->range;
int i;
if (range->pins) {
for (i = 0; i < range->npins; i++) {
if (range->pins[i] == pin)
return range->base + i - chip->base;
}
} else {
if (pin >= range->pin_base &&
pin < range->pin_base + range->npins) {
unsigned gpio_base;
gpio_base = range->base - chip->base;
return gpio_base + pin - range->pin_base;
}
}
}
return -EINVAL;
}
#else
static inline int acpi_gpiochip_pin_to_gpio_offset(struct gpio_chip *chip,
int pin)
{
return pin;
}
#endif
/**
* acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with GPIO API
* @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
* @pin: ACPI GPIO pin number (0-based, controller-relative)
*
* Return: GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR
* error value. Specifically returns %-EPROBE_DEFER if the referenced GPIO
* controller does not have gpiochip registered at the moment. This is to
* support probe deferral.
*/
static struct gpio_desc *acpi_get_gpiod(char *path, int pin)
{
struct gpio_chip *chip;
acpi_handle handle;
acpi_status status;
int offset;
status = acpi_get_handle(NULL, path, &handle);
if (ACPI_FAILURE(status))
return ERR_PTR(-ENODEV);
chip = gpiochip_find(handle, acpi_gpiochip_find);
if (!chip)
return ERR_PTR(-EPROBE_DEFER);
offset = acpi_gpiochip_pin_to_gpio_offset(chip, pin);
if (offset < 0)
return ERR_PTR(offset);
return gpiochip_get_desc(chip, offset);
}
static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
{
struct acpi_gpio_event *event = data;
acpi_evaluate_object(event->handle, NULL, NULL, NULL);
return IRQ_HANDLED;
}
static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
{
struct acpi_gpio_event *event = data;
acpi_execute_simple_method(event->handle, NULL, event->pin);
return IRQ_HANDLED;
}
static void acpi_gpio_chip_dh(acpi_handle handle, void *data)
{
/* The address of this function is used as a key. */
}
static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
void *context)
{
struct acpi_gpio_chip *acpi_gpio = context;
struct gpio_chip *chip = acpi_gpio->chip;
struct acpi_resource_gpio *agpio;
acpi_handle handle, evt_handle;
struct acpi_gpio_event *event;
irq_handler_t handler = NULL;
struct gpio_desc *desc;
unsigned long irqflags;
int ret, pin, irq;
if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
return AE_OK;
agpio = &ares->data.gpio;
if (agpio->connection_type != ACPI_RESOURCE_GPIO_TYPE_INT)
return AE_OK;
handle = ACPI_HANDLE(chip->parent);
pin = agpio->pin_table[0];
if (pin <= 255) {
char ev_name[5];
sprintf(ev_name, "_%c%02X",
agpio->triggering == ACPI_EDGE_SENSITIVE ? 'E' : 'L',
pin);
if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))
handler = acpi_gpio_irq_handler;
}
if (!handler) {
if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle)))
handler = acpi_gpio_irq_handler_evt;
}
if (!handler)
return AE_BAD_PARAMETER;
pin = acpi_gpiochip_pin_to_gpio_offset(chip, pin);
if (pin < 0)
return AE_BAD_PARAMETER;
desc = gpiochip_request_own_desc(chip, pin, "ACPI:Event");
if (IS_ERR(desc)) {
dev_err(chip->parent, "Failed to request GPIO\n");
return AE_ERROR;
}
gpiod_direction_input(desc);
ret = gpiochip_lock_as_irq(chip, pin);
if (ret) {
dev_err(chip->parent, "Failed to lock GPIO as interrupt\n");
goto fail_free_desc;
}
irq = gpiod_to_irq(desc);
if (irq < 0) {
dev_err(chip->parent, "Failed to translate GPIO to IRQ\n");
goto fail_unlock_irq;
}
irqflags = IRQF_ONESHOT;
if (agpio->triggering == ACPI_LEVEL_SENSITIVE) {
if (agpio->polarity == ACPI_ACTIVE_HIGH)
irqflags |= IRQF_TRIGGER_HIGH;
else
irqflags |= IRQF_TRIGGER_LOW;
} else {
switch (agpio->polarity) {
case ACPI_ACTIVE_HIGH:
irqflags |= IRQF_TRIGGER_RISING;
break;
case ACPI_ACTIVE_LOW:
irqflags |= IRQF_TRIGGER_FALLING;
break;
default:
irqflags |= IRQF_TRIGGER_RISING |
IRQF_TRIGGER_FALLING;
break;
}
}
event = kzalloc(sizeof(*event), GFP_KERNEL);
if (!event)
goto fail_unlock_irq;
event->handle = evt_handle;
event->irq = irq;
event->pin = pin;
event->desc = desc;
ret = request_threaded_irq(event->irq, NULL, handler, irqflags,
"ACPI:Event", event);
if (ret) {
dev_err(chip->parent,
"Failed to setup interrupt handler for %d\n",
event->irq);
goto fail_free_event;
}
list_add_tail(&event->node, &acpi_gpio->events);
return AE_OK;
fail_free_event:
kfree(event);
fail_unlock_irq:
gpiochip_unlock_as_irq(chip, pin);
fail_free_desc:
gpiochip_free_own_desc(desc);
return AE_ERROR;
}
/**
* acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
* @chip: GPIO chip
*
* ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
* handled by ACPI event methods which need to be called from the GPIO
* chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
* gpio pins have acpi event methods and assigns interrupt handlers that calls
* the acpi event methods for those pins.
*/
void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
{
struct acpi_gpio_chip *acpi_gpio;
acpi_handle handle;
acpi_status status;
if (!chip->parent || !chip->to_irq)
return;
handle = ACPI_HANDLE(chip->parent);
if (!handle)
return;
status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
if (ACPI_FAILURE(status))
return;
acpi_walk_resources(handle, "_AEI",
acpi_gpiochip_request_interrupt, acpi_gpio);
}
EXPORT_SYMBOL_GPL(acpi_gpiochip_request_interrupts);
/**
* acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
* @chip: GPIO chip
*
* Free interrupts associated with GPIO ACPI event method for the given
* GPIO chip.
*/
void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
{
struct acpi_gpio_chip *acpi_gpio;
struct acpi_gpio_event *event, *ep;
acpi_handle handle;
acpi_status status;
if (!chip->parent || !chip->to_irq)
return;
handle = ACPI_HANDLE(chip->parent);
if (!handle)
return;
status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
if (ACPI_FAILURE(status))
return;
list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
struct gpio_desc *desc;
free_irq(event->irq, event);
desc = event->desc;
if (WARN_ON(IS_ERR(desc)))
continue;
gpiochip_unlock_as_irq(chip, event->pin);
gpiochip_free_own_desc(desc);
list_del(&event->node);
kfree(event);
}
}
EXPORT_SYMBOL_GPL(acpi_gpiochip_free_interrupts);
int acpi_dev_add_driver_gpios(struct acpi_device *adev,
const struct acpi_gpio_mapping *gpios)
{
if (adev && gpios) {
adev->driver_gpios = gpios;
return 0;
}
return -EINVAL;
}
EXPORT_SYMBOL_GPL(acpi_dev_add_driver_gpios);
static bool acpi_get_driver_gpio_data(struct acpi_device *adev,
const char *name, int index,
struct acpi_reference_args *args)
{
const struct acpi_gpio_mapping *gm;
if (!adev->driver_gpios)
return false;
for (gm = adev->driver_gpios; gm->name; gm++)
if (!strcmp(name, gm->name) && gm->data && index < gm->size) {
const struct acpi_gpio_params *par = gm->data + index;
args->adev = adev;
args->args[0] = par->crs_entry_index;
args->args[1] = par->line_index;
args->args[2] = par->active_low;
args->nargs = 3;
return true;
}
return false;
}
struct acpi_gpio_lookup {
struct acpi_gpio_info info;
int index;
int pin_index;
bool active_low;
struct acpi_device *adev;
struct gpio_desc *desc;
int n;
};
static int acpi_find_gpio(struct acpi_resource *ares, void *data)
{
struct acpi_gpio_lookup *lookup = data;
if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
return 1;
if (lookup->n++ == lookup->index && !lookup->desc) {
const struct acpi_resource_gpio *agpio = &ares->data.gpio;
int pin_index = lookup->pin_index;
if (pin_index >= agpio->pin_table_length)
return 1;
lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
agpio->pin_table[pin_index]);
lookup->info.gpioint =
agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
/*
* ActiveLow is only specified for GpioInt resource. If
* GpioIo is used then the only way to set the flag is
* to use _DSD "gpios" property.
* Note: we expect here:
* - ACPI_ACTIVE_LOW == GPIO_ACTIVE_LOW
* - ACPI_ACTIVE_HIGH == GPIO_ACTIVE_HIGH
*/
if (lookup->info.gpioint) {
lookup->info.polarity = agpio->polarity;
lookup->info.triggering = agpio->triggering;
}
}
return 1;
}
static int acpi_gpio_resource_lookup(struct acpi_gpio_lookup *lookup,
struct acpi_gpio_info *info)
{
struct list_head res_list;
int ret;
INIT_LIST_HEAD(&res_list);
ret = acpi_dev_get_resources(lookup->adev, &res_list, acpi_find_gpio,
lookup);
if (ret < 0)
return ret;
acpi_dev_free_resource_list(&res_list);
if (!lookup->desc)
return -ENOENT;
if (info) {
*info = lookup->info;
if (lookup->active_low)
info->polarity = lookup->active_low;
}
return 0;
}
static int acpi_gpio_property_lookup(struct fwnode_handle *fwnode,
const char *propname, int index,
struct acpi_gpio_lookup *lookup)
{
struct acpi_reference_args args;
int ret;
memset(&args, 0, sizeof(args));
ret = acpi_node_get_property_reference(fwnode, propname, index, &args);
if (ret) {
struct acpi_device *adev = to_acpi_device_node(fwnode);
if (!adev)
return ret;
if (!acpi_get_driver_gpio_data(adev, propname, index, &args))
return ret;
}
/*
* The property was found and resolved, so need to lookup the GPIO based
* on returned args.
*/
lookup->adev = args.adev;
if (args.nargs >= 2) {
lookup->index = args.args[0];
lookup->pin_index = args.args[1];
/* 3rd argument, if present is used to specify active_low. */
if (args.nargs >= 3)
lookup->active_low = !!args.args[2];
}
return 0;
}
/**
* acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
* @adev: pointer to a ACPI device to get GPIO from
* @propname: Property name of the GPIO (optional)
* @index: index of GpioIo/GpioInt resource (starting from %0)
* @info: info pointer to fill in (optional)
*
* Function goes through ACPI resources for @adev and based on @index looks
* up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
* and returns it. @index matches GpioIo/GpioInt resources only so if there
* are total %3 GPIO resources, the index goes from %0 to %2.
*
* If @propname is specified the GPIO is looked using device property. In
* that case @index is used to select the GPIO entry in the property value
* (in case of multiple).
*
* If the GPIO cannot be translated or there is an error an ERR_PTR is
* returned.
*
* Note: if the GPIO resource has multiple entries in the pin list, this
* function only returns the first.
*/
struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
const char *propname, int index,
struct acpi_gpio_info *info)
{
struct acpi_gpio_lookup lookup;
int ret;
if (!adev)
return ERR_PTR(-ENODEV);
memset(&lookup, 0, sizeof(lookup));
lookup.index = index;
if (propname) {
dev_dbg(&adev->dev, "GPIO: looking up %s\n", propname);
ret = acpi_gpio_property_lookup(acpi_fwnode_handle(adev),
propname, index, &lookup);
if (ret)
return ERR_PTR(ret);
dev_dbg(&adev->dev, "GPIO: _DSD returned %s %d %d %u\n",
dev_name(&lookup.adev->dev), lookup.index,
lookup.pin_index, lookup.active_low);
} else {
dev_dbg(&adev->dev, "GPIO: looking up %d in _CRS\n", index);
lookup.adev = adev;
}
ret = acpi_gpio_resource_lookup(&lookup, info);
return ret ? ERR_PTR(ret) : lookup.desc;
}
/**
* acpi_node_get_gpiod() - get a GPIO descriptor from ACPI resources
* @fwnode: pointer to an ACPI firmware node to get the GPIO information from
* @propname: Property name of the GPIO
* @index: index of GpioIo/GpioInt resource (starting from %0)
* @info: info pointer to fill in (optional)
*
* If @fwnode is an ACPI device object, call %acpi_get_gpiod_by_index() for it.
* Otherwise (ie. it is a data-only non-device object), use the property-based
* GPIO lookup to get to the GPIO resource with the relevant information and use
* that to obtain the GPIO descriptor to return.
*/
struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
const char *propname, int index,
struct acpi_gpio_info *info)
{
struct acpi_gpio_lookup lookup;
struct acpi_device *adev;
int ret;
adev = to_acpi_device_node(fwnode);
if (adev)
return acpi_get_gpiod_by_index(adev, propname, index, info);
if (!is_acpi_data_node(fwnode))
return ERR_PTR(-ENODEV);
if (!propname)
return ERR_PTR(-EINVAL);
memset(&lookup, 0, sizeof(lookup));
lookup.index = index;
ret = acpi_gpio_property_lookup(fwnode, propname, index, &lookup);
if (ret)
return ERR_PTR(ret);
ret = acpi_gpio_resource_lookup(&lookup, info);
return ret ? ERR_PTR(ret) : lookup.desc;
}
/**
* acpi_dev_gpio_irq_get() - Find GpioInt and translate it to Linux IRQ number
* @adev: pointer to a ACPI device to get IRQ from
* @index: index of GpioInt resource (starting from %0)
*
* If the device has one or more GpioInt resources, this function can be
* used to translate from the GPIO offset in the resource to the Linux IRQ
* number.
*
* Return: Linux IRQ number (>%0) on success, negative errno on failure.
*/
int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
{
int idx, i;
unsigned int irq_flags;
for (i = 0, idx = 0; idx <= index; i++) {
struct acpi_gpio_info info;
struct gpio_desc *desc;
desc = acpi_get_gpiod_by_index(adev, NULL, i, &info);
if (IS_ERR(desc))
break;
if (info.gpioint && idx++ == index) {
int irq = gpiod_to_irq(desc);
if (irq < 0)
return irq;
irq_flags = acpi_dev_get_irq_type(info.triggering,
info.polarity);
/* Set type if specified and different than the current one */
if (irq_flags != IRQ_TYPE_NONE &&
irq_flags != irq_get_trigger_type(irq))
irq_set_irq_type(irq, irq_flags);
return irq;
}
}
return -ENOENT;
}
EXPORT_SYMBOL_GPL(acpi_dev_gpio_irq_get);
static acpi_status
acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
u32 bits, u64 *value, void *handler_context,
void *region_context)
{
struct acpi_gpio_chip *achip = region_context;
struct gpio_chip *chip = achip->chip;
struct acpi_resource_gpio *agpio;
struct acpi_resource *ares;
int pin_index = (int)address;
acpi_status status;
bool pull_up;
int length;
int i;
status = acpi_buffer_to_resource(achip->conn_info.connection,
achip->conn_info.length, &ares);
if (ACPI_FAILURE(status))
return status;
if (WARN_ON(ares->type != ACPI_RESOURCE_TYPE_GPIO)) {
ACPI_FREE(ares);
return AE_BAD_PARAMETER;
}
agpio = &ares->data.gpio;
pull_up = agpio->pin_config == ACPI_PIN_CONFIG_PULLUP;
if (WARN_ON(agpio->io_restriction == ACPI_IO_RESTRICT_INPUT &&
function == ACPI_WRITE)) {
ACPI_FREE(ares);
return AE_BAD_PARAMETER;
}
length = min(agpio->pin_table_length, (u16)(pin_index + bits));
for (i = pin_index; i < length; ++i) {
int pin = agpio->pin_table[i];
struct acpi_gpio_connection *conn;
struct gpio_desc *desc;
bool found;
pin = acpi_gpiochip_pin_to_gpio_offset(chip, pin);
if (pin < 0) {
status = AE_BAD_PARAMETER;
goto out;
}
mutex_lock(&achip->conn_lock);
found = false;
list_for_each_entry(conn, &achip->conns, node) {
if (conn->pin == pin) {
found = true;
desc = conn->desc;
break;
}
}
/*
* The same GPIO can be shared between operation region and
* event but only if the access here is ACPI_READ. In that
* case we "borrow" the event GPIO instead.
*/
if (!found && agpio->sharable == ACPI_SHARED &&
function == ACPI_READ) {
struct acpi_gpio_event *event;
list_for_each_entry(event, &achip->events, node) {
if (event->pin == pin) {
desc = event->desc;
found = true;
break;
}
}
}
if (!found) {
desc = gpiochip_request_own_desc(chip, pin,
"ACPI:OpRegion");
if (IS_ERR(desc)) {
status = AE_ERROR;
mutex_unlock(&achip->conn_lock);
goto out;
}
switch (agpio->io_restriction) {
case ACPI_IO_RESTRICT_INPUT:
gpiod_direction_input(desc);
break;
case ACPI_IO_RESTRICT_OUTPUT:
/*
* ACPI GPIO resources don't contain an
* initial value for the GPIO. Therefore we
* deduce that value from the pull field
* instead. If the pin is pulled up we
* assume default to be high, otherwise
* low.
*/
gpiod_direction_output(desc, pull_up);
break;
default:
/*
* Assume that the BIOS has configured the
* direction and pull accordingly.
*/
break;
}
conn = kzalloc(sizeof(*conn), GFP_KERNEL);
if (!conn) {
status = AE_NO_MEMORY;
gpiochip_free_own_desc(desc);
mutex_unlock(&achip->conn_lock);
goto out;
}
conn->pin = pin;
conn->desc = desc;
list_add_tail(&conn->node, &achip->conns);
}
mutex_unlock(&achip->conn_lock);
if (function == ACPI_WRITE)
gpiod_set_raw_value_cansleep(desc,
!!((1 << i) & *value));
else
*value |= (u64)gpiod_get_raw_value_cansleep(desc) << i;
}
out:
ACPI_FREE(ares);
return status;
}
static void acpi_gpiochip_request_regions(struct acpi_gpio_chip *achip)
{
struct gpio_chip *chip = achip->chip;
acpi_handle handle = ACPI_HANDLE(chip->parent);
acpi_status status;
INIT_LIST_HEAD(&achip->conns);
mutex_init(&achip->conn_lock);
status = acpi_install_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
acpi_gpio_adr_space_handler,
NULL, achip);
if (ACPI_FAILURE(status))
dev_err(chip->parent,
"Failed to install GPIO OpRegion handler\n");
}
static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip)
{
struct gpio_chip *chip = achip->chip;
acpi_handle handle = ACPI_HANDLE(chip->parent);
struct acpi_gpio_connection *conn, *tmp;
acpi_status status;
status = acpi_remove_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
acpi_gpio_adr_space_handler);
if (ACPI_FAILURE(status)) {
dev_err(chip->parent,
"Failed to remove GPIO OpRegion handler\n");
return;
}
list_for_each_entry_safe_reverse(conn, tmp, &achip->conns, node) {
gpiochip_free_own_desc(conn->desc);
list_del(&conn->node);
kfree(conn);
}
}
void acpi_gpiochip_add(struct gpio_chip *chip)
{
struct acpi_gpio_chip *acpi_gpio;
acpi_handle handle;
acpi_status status;
if (!chip || !chip->parent)
return;
handle = ACPI_HANDLE(chip->parent);
if (!handle)
return;
acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
if (!acpi_gpio) {
dev_err(chip->parent,
"Failed to allocate memory for ACPI GPIO chip\n");
return;
}
acpi_gpio->chip = chip;
INIT_LIST_HEAD(&acpi_gpio->events);
status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
if (ACPI_FAILURE(status)) {
dev_err(chip->parent, "Failed to attach ACPI GPIO chip\n");
kfree(acpi_gpio);
return;
}
acpi_gpiochip_request_regions(acpi_gpio);
}
void acpi_gpiochip_remove(struct gpio_chip *chip)
{
struct acpi_gpio_chip *acpi_gpio;
acpi_handle handle;
acpi_status status;
if (!chip || !chip->parent)
return;
handle = ACPI_HANDLE(chip->parent);
if (!handle)
return;
status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
if (ACPI_FAILURE(status)) {
dev_warn(chip->parent, "Failed to retrieve ACPI GPIO chip\n");
return;
}
acpi_gpiochip_free_regions(acpi_gpio);
acpi_detach_data(handle, acpi_gpio_chip_dh);
kfree(acpi_gpio);
}
static unsigned int acpi_gpio_package_count(const union acpi_object *obj)
{
const union acpi_object *element = obj->package.elements;
const union acpi_object *end = element + obj->package.count;
unsigned int count = 0;
while (element < end) {
if (element->type == ACPI_TYPE_LOCAL_REFERENCE)
count++;
element++;
}
return count;
}
static int acpi_find_gpio_count(struct acpi_resource *ares, void *data)
{
unsigned int *count = data;
if (ares->type == ACPI_RESOURCE_TYPE_GPIO)
*count += ares->data.gpio.pin_table_length;
return 1;
}
/**
* acpi_gpio_count - return the number of GPIOs associated with a
* device / function or -ENOENT if no GPIO has been
* assigned to the requested function.
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
*/
int acpi_gpio_count(struct device *dev, const char *con_id)
{
struct acpi_device *adev = ACPI_COMPANION(dev);
const union acpi_object *obj;
const struct acpi_gpio_mapping *gm;
int count = -ENOENT;
int ret;
char propname[32];
unsigned int i;
/* Try first from _DSD */
for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
if (con_id && strcmp(con_id, "gpios"))
snprintf(propname, sizeof(propname), "%s-%s",
con_id, gpio_suffixes[i]);
else
snprintf(propname, sizeof(propname), "%s",
gpio_suffixes[i]);
ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY,
&obj);
if (ret == 0) {
if (obj->type == ACPI_TYPE_LOCAL_REFERENCE)
count = 1;
else if (obj->type == ACPI_TYPE_PACKAGE)
count = acpi_gpio_package_count(obj);
} else if (adev->driver_gpios) {
for (gm = adev->driver_gpios; gm->name; gm++)
if (strcmp(propname, gm->name) == 0) {
count = gm->size;
break;
}
}
if (count >= 0)
break;
}
/* Then from plain _CRS GPIOs */
if (count < 0) {
struct list_head resource_list;
unsigned int crs_count = 0;
INIT_LIST_HEAD(&resource_list);
acpi_dev_get_resources(adev, &resource_list,
acpi_find_gpio_count, &crs_count);
acpi_dev_free_resource_list(&resource_list);
if (crs_count > 0)
count = crs_count;
}
return count;
}
struct acpi_crs_lookup {
struct list_head node;
struct acpi_device *adev;
const char *con_id;
};
static DEFINE_MUTEX(acpi_crs_lookup_lock);
static LIST_HEAD(acpi_crs_lookup_list);
bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id)
{
struct acpi_crs_lookup *l, *lookup = NULL;
/* Never allow fallback if the device has properties */
if (adev->data.properties || adev->driver_gpios)
return false;
mutex_lock(&acpi_crs_lookup_lock);
list_for_each_entry(l, &acpi_crs_lookup_list, node) {
if (l->adev == adev) {
lookup = l;
break;
}
}
if (!lookup) {
lookup = kmalloc(sizeof(*lookup), GFP_KERNEL);
if (lookup) {
lookup->adev = adev;
lookup->con_id = con_id;
list_add_tail(&lookup->node, &acpi_crs_lookup_list);
}
}
mutex_unlock(&acpi_crs_lookup_lock);
return lookup &&
((!lookup->con_id && !con_id) ||
(lookup->con_id && con_id &&
strcmp(lookup->con_id, con_id) == 0));
}