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gpiolib-acpi.c
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gpiolib-acpi.c
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// SPDX-License-Identifier: GPL-2.0
/*
* 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>
*/
#include <linux/dmi.h>
#include <linux/errno.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.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"
#include "gpiolib-acpi.h"
static int run_edge_events_on_boot = -1;
module_param(run_edge_events_on_boot, int, 0444);
MODULE_PARM_DESC(run_edge_events_on_boot,
"Run edge _AEI event-handlers at boot: 0=no, 1=yes, -1=auto");
static char *ignore_wake;
module_param(ignore_wake, charp, 0444);
MODULE_PARM_DESC(ignore_wake,
"controller@pin combos on which to ignore the ACPI wake flag "
"ignore_wake=controller@pin[,controller@pin[,...]]");
struct acpi_gpiolib_dmi_quirk {
bool no_edge_events_on_boot;
char *ignore_wake;
};
/**
* struct acpi_gpio_event - ACPI GPIO event handler data
*
* @node: list-entry of the events list of the struct acpi_gpio_chip
* @handle: handle of ACPI method to execute when the IRQ triggers
* @handler: handler function to pass to request_irq() when requesting the IRQ
* @pin: GPIO pin number on the struct gpio_chip
* @irq: Linux IRQ number for the event, for request_irq() / free_irq()
* @irqflags: flags to pass to request_irq() when requesting the IRQ
* @irq_is_wake: If the ACPI flags indicate the IRQ is a wakeup source
* @irq_requested:True if request_irq() has been done
* @desc: struct gpio_desc for the GPIO pin for this event
*/
struct acpi_gpio_event {
struct list_head node;
acpi_handle handle;
irq_handler_t handler;
unsigned int pin;
unsigned int irq;
unsigned long irqflags;
bool irq_is_wake;
bool irq_requested;
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;
struct list_head deferred_req_irqs_list_entry;
};
/*
* For GPIO chips which call acpi_gpiochip_request_interrupts() before late_init
* (so builtin drivers) we register the ACPI GpioInt IRQ handlers from a
* late_initcall_sync() handler, so that other builtin drivers can register their
* OpRegions before the event handlers can run. This list contains GPIO chips
* for which the acpi_gpiochip_request_irqs() call has been deferred.
*/
static DEFINE_MUTEX(acpi_gpio_deferred_req_irqs_lock);
static LIST_HEAD(acpi_gpio_deferred_req_irqs_list);
static bool acpi_gpio_deferred_req_irqs_done;
static int acpi_gpiochip_find(struct gpio_chip *gc, void *data)
{
if (!gc->parent)
return false;
return ACPI_HANDLE(gc->parent) == data;
}
/**
* 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 GPIO chip 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;
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);
return gpiochip_get_desc(chip, pin);
}
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. */
}
bool acpi_gpio_get_irq_resource(struct acpi_resource *ares,
struct acpi_resource_gpio **agpio)
{
struct acpi_resource_gpio *gpio;
if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
return false;
gpio = &ares->data.gpio;
if (gpio->connection_type != ACPI_RESOURCE_GPIO_TYPE_INT)
return false;
*agpio = gpio;
return true;
}
EXPORT_SYMBOL_GPL(acpi_gpio_get_irq_resource);
static void acpi_gpiochip_request_irq(struct acpi_gpio_chip *acpi_gpio,
struct acpi_gpio_event *event)
{
int ret, value;
ret = request_threaded_irq(event->irq, NULL, event->handler,
event->irqflags, "ACPI:Event", event);
if (ret) {
dev_err(acpi_gpio->chip->parent,
"Failed to setup interrupt handler for %d\n",
event->irq);
return;
}
if (event->irq_is_wake)
enable_irq_wake(event->irq);
event->irq_requested = true;
/* Make sure we trigger the initial state of edge-triggered IRQs */
if (run_edge_events_on_boot &&
(event->irqflags & (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING))) {
value = gpiod_get_raw_value_cansleep(event->desc);
if (((event->irqflags & IRQF_TRIGGER_RISING) && value == 1) ||
((event->irqflags & IRQF_TRIGGER_FALLING) && value == 0))
event->handler(event->irq, event);
}
}
static void acpi_gpiochip_request_irqs(struct acpi_gpio_chip *acpi_gpio)
{
struct acpi_gpio_event *event;
list_for_each_entry(event, &acpi_gpio->events, node)
acpi_gpiochip_request_irq(acpi_gpio, event);
}
static enum gpiod_flags
acpi_gpio_to_gpiod_flags(const struct acpi_resource_gpio *agpio, int polarity)
{
/* GpioInt() implies input configuration */
if (agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT)
return GPIOD_IN;
switch (agpio->io_restriction) {
case ACPI_IO_RESTRICT_INPUT:
return GPIOD_IN;
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
* and the polarity instead. If the pin is pulled up we assume
* default to be high, if it is pulled down we assume default
* to be low, otherwise we leave pin untouched. For active low
* polarity values will be switched. See also
* Documentation/firmware-guide/acpi/gpio-properties.rst.
*/
switch (agpio->pin_config) {
case ACPI_PIN_CONFIG_PULLUP:
return polarity == GPIO_ACTIVE_LOW ? GPIOD_OUT_LOW : GPIOD_OUT_HIGH;
case ACPI_PIN_CONFIG_PULLDOWN:
return polarity == GPIO_ACTIVE_LOW ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
default:
break;
}
break;
default:
break;
}
/*
* Assume that the BIOS has configured the direction and pull
* accordingly.
*/
return GPIOD_ASIS;
}
static struct gpio_desc *acpi_request_own_gpiod(struct gpio_chip *chip,
struct acpi_resource_gpio *agpio,
unsigned int index,
const char *label)
{
int polarity = GPIO_ACTIVE_HIGH;
enum gpiod_flags flags = acpi_gpio_to_gpiod_flags(agpio, polarity);
unsigned int pin = agpio->pin_table[index];
struct gpio_desc *desc;
int ret;
desc = gpiochip_request_own_desc(chip, pin, label, polarity, flags);
if (IS_ERR(desc))
return desc;
ret = gpio_set_debounce_timeout(desc, agpio->debounce_timeout);
if (ret)
gpiochip_free_own_desc(desc);
return ret ? ERR_PTR(ret) : desc;
}
static bool acpi_gpio_in_ignore_list(const char *controller_in, int pin_in)
{
const char *controller, *pin_str;
int len, pin;
char *endp;
controller = ignore_wake;
while (controller) {
pin_str = strchr(controller, '@');
if (!pin_str)
goto err;
len = pin_str - controller;
if (len == strlen(controller_in) &&
strncmp(controller, controller_in, len) == 0) {
pin = simple_strtoul(pin_str + 1, &endp, 10);
if (*endp != 0 && *endp != ',')
goto err;
if (pin == pin_in)
return true;
}
controller = strchr(controller, ',');
if (controller)
controller++;
}
return false;
err:
pr_err_once("Error invalid value for gpiolib_acpi.ignore_wake: %s\n",
ignore_wake);
return false;
}
static bool acpi_gpio_irq_is_wake(struct device *parent,
struct acpi_resource_gpio *agpio)
{
int pin = agpio->pin_table[0];
if (agpio->wake_capable != ACPI_WAKE_CAPABLE)
return false;
if (acpi_gpio_in_ignore_list(dev_name(parent), pin)) {
dev_info(parent, "Ignoring wakeup on pin %d\n", pin);
return false;
}
return true;
}
/* Always returns AE_OK so that we keep looping over the resources */
static acpi_status acpi_gpiochip_alloc_event(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;
int ret, pin, irq;
if (!acpi_gpio_get_irq_resource(ares, &agpio))
return AE_OK;
handle = ACPI_HANDLE(chip->parent);
pin = agpio->pin_table[0];
if (pin <= 255) {
char ev_name[5];
sprintf(ev_name, "_%c%02hhX",
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_OK;
desc = acpi_request_own_gpiod(chip, agpio, 0, "ACPI:Event");
if (IS_ERR(desc)) {
dev_err(chip->parent,
"Failed to request GPIO for pin 0x%04X, err %ld\n",
pin, PTR_ERR(desc));
return AE_OK;
}
ret = gpiochip_lock_as_irq(chip, pin);
if (ret) {
dev_err(chip->parent,
"Failed to lock GPIO pin 0x%04X as interrupt, err %d\n",
pin, ret);
goto fail_free_desc;
}
irq = gpiod_to_irq(desc);
if (irq < 0) {
dev_err(chip->parent,
"Failed to translate GPIO pin 0x%04X to IRQ, err %d\n",
pin, irq);
goto fail_unlock_irq;
}
event = kzalloc(sizeof(*event), GFP_KERNEL);
if (!event)
goto fail_unlock_irq;
event->irqflags = IRQF_ONESHOT;
if (agpio->triggering == ACPI_LEVEL_SENSITIVE) {
if (agpio->polarity == ACPI_ACTIVE_HIGH)
event->irqflags |= IRQF_TRIGGER_HIGH;
else
event->irqflags |= IRQF_TRIGGER_LOW;
} else {
switch (agpio->polarity) {
case ACPI_ACTIVE_HIGH:
event->irqflags |= IRQF_TRIGGER_RISING;
break;
case ACPI_ACTIVE_LOW:
event->irqflags |= IRQF_TRIGGER_FALLING;
break;
default:
event->irqflags |= IRQF_TRIGGER_RISING |
IRQF_TRIGGER_FALLING;
break;
}
}
event->handle = evt_handle;
event->handler = handler;
event->irq = irq;
event->irq_is_wake = acpi_gpio_irq_is_wake(chip->parent, agpio);
event->pin = pin;
event->desc = desc;
list_add_tail(&event->node, &acpi_gpio->events);
return AE_OK;
fail_unlock_irq:
gpiochip_unlock_as_irq(chip, pin);
fail_free_desc:
gpiochip_free_own_desc(desc);
return AE_OK;
}
/**
* 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;
bool defer;
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_alloc_event, acpi_gpio);
mutex_lock(&acpi_gpio_deferred_req_irqs_lock);
defer = !acpi_gpio_deferred_req_irqs_done;
if (defer)
list_add(&acpi_gpio->deferred_req_irqs_list_entry,
&acpi_gpio_deferred_req_irqs_list);
mutex_unlock(&acpi_gpio_deferred_req_irqs_lock);
if (defer)
return;
acpi_gpiochip_request_irqs(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;
mutex_lock(&acpi_gpio_deferred_req_irqs_lock);
if (!list_empty(&acpi_gpio->deferred_req_irqs_list_entry))
list_del_init(&acpi_gpio->deferred_req_irqs_list_entry);
mutex_unlock(&acpi_gpio_deferred_req_irqs_lock);
list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
if (event->irq_requested) {
if (event->irq_is_wake)
disable_irq_wake(event->irq);
free_irq(event->irq, event);
}
gpiochip_unlock_as_irq(chip, event->pin);
gpiochip_free_own_desc(event->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);
void acpi_dev_remove_driver_gpios(struct acpi_device *adev)
{
if (adev)
adev->driver_gpios = NULL;
}
EXPORT_SYMBOL_GPL(acpi_dev_remove_driver_gpios);
static void devm_acpi_dev_release_driver_gpios(struct device *dev, void *res)
{
acpi_dev_remove_driver_gpios(ACPI_COMPANION(dev));
}
int devm_acpi_dev_add_driver_gpios(struct device *dev,
const struct acpi_gpio_mapping *gpios)
{
void *res;
int ret;
res = devres_alloc(devm_acpi_dev_release_driver_gpios, 0, GFP_KERNEL);
if (!res)
return -ENOMEM;
ret = acpi_dev_add_driver_gpios(ACPI_COMPANION(dev), gpios);
if (ret) {
devres_free(res);
return ret;
}
devres_add(dev, res);
return 0;
}
EXPORT_SYMBOL_GPL(devm_acpi_dev_add_driver_gpios);
void devm_acpi_dev_remove_driver_gpios(struct device *dev)
{
WARN_ON(devres_release(dev, devm_acpi_dev_release_driver_gpios, NULL, NULL));
}
EXPORT_SYMBOL_GPL(devm_acpi_dev_remove_driver_gpios);
static bool acpi_get_driver_gpio_data(struct acpi_device *adev,
const char *name, int index,
struct fwnode_reference_args *args,
unsigned int *quirks)
{
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->fwnode = acpi_fwnode_handle(adev);
args->args[0] = par->crs_entry_index;
args->args[1] = par->line_index;
args->args[2] = par->active_low;
args->nargs = 3;
*quirks = gm->quirks;
return true;
}
return false;
}
static int
__acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags, enum gpiod_flags update)
{
const enum gpiod_flags mask =
GPIOD_FLAGS_BIT_DIR_SET | GPIOD_FLAGS_BIT_DIR_OUT |
GPIOD_FLAGS_BIT_DIR_VAL;
int ret = 0;
/*
* Check if the BIOS has IoRestriction with explicitly set direction
* and update @flags accordingly. Otherwise use whatever caller asked
* for.
*/
if (update & GPIOD_FLAGS_BIT_DIR_SET) {
enum gpiod_flags diff = *flags ^ update;
/*
* Check if caller supplied incompatible GPIO initialization
* flags.
*
* Return %-EINVAL to notify that firmware has different
* settings and we are going to use them.
*/
if (((*flags & GPIOD_FLAGS_BIT_DIR_SET) && (diff & GPIOD_FLAGS_BIT_DIR_OUT)) ||
((*flags & GPIOD_FLAGS_BIT_DIR_OUT) && (diff & GPIOD_FLAGS_BIT_DIR_VAL)))
ret = -EINVAL;
*flags = (*flags & ~mask) | (update & mask);
}
return ret;
}
int
acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags, struct acpi_gpio_info *info)
{
struct device *dev = &info->adev->dev;
enum gpiod_flags old = *flags;
int ret;
ret = __acpi_gpio_update_gpiod_flags(&old, info->flags);
if (info->quirks & ACPI_GPIO_QUIRK_NO_IO_RESTRICTION) {
if (ret)
dev_warn(dev, FW_BUG "GPIO not in correct mode, fixing\n");
} else {
if (ret)
dev_dbg(dev, "Override GPIO initialization flags\n");
*flags = old;
}
return ret;
}
int acpi_gpio_update_gpiod_lookup_flags(unsigned long *lookupflags,
struct acpi_gpio_info *info)
{
switch (info->pin_config) {
case ACPI_PIN_CONFIG_PULLUP:
*lookupflags |= GPIO_PULL_UP;
break;
case ACPI_PIN_CONFIG_PULLDOWN:
*lookupflags |= GPIO_PULL_DOWN;
break;
default:
break;
}
if (info->polarity == GPIO_ACTIVE_LOW)
*lookupflags |= GPIO_ACTIVE_LOW;
return 0;
}
struct acpi_gpio_lookup {
struct acpi_gpio_info info;
int index;
u16 pin_index;
bool active_low;
struct gpio_desc *desc;
int n;
};
static int acpi_populate_gpio_lookup(struct acpi_resource *ares, void *data)
{
struct acpi_gpio_lookup *lookup = data;
if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
return 1;
if (!lookup->desc) {
const struct acpi_resource_gpio *agpio = &ares->data.gpio;
bool gpioint = agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
struct gpio_desc *desc;
u16 pin_index;
if (lookup->info.quirks & ACPI_GPIO_QUIRK_ONLY_GPIOIO && gpioint)
lookup->index++;
if (lookup->n++ != lookup->index)
return 1;
pin_index = lookup->pin_index;
if (pin_index >= agpio->pin_table_length)
return 1;
if (lookup->info.quirks & ACPI_GPIO_QUIRK_ABSOLUTE_NUMBER)
desc = gpio_to_desc(agpio->pin_table[pin_index]);
else
desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
agpio->pin_table[pin_index]);
lookup->desc = desc;
lookup->info.pin_config = agpio->pin_config;
lookup->info.debounce = agpio->debounce_timeout;
lookup->info.gpioint = gpioint;
/*
* Polarity and triggering are only specified for GpioInt
* resource.
* 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;
} else {
lookup->info.polarity = lookup->active_low;
}
lookup->info.flags = acpi_gpio_to_gpiod_flags(agpio, lookup->info.polarity);
}
return 1;
}
static int acpi_gpio_resource_lookup(struct acpi_gpio_lookup *lookup,
struct acpi_gpio_info *info)
{
struct acpi_device *adev = lookup->info.adev;
struct list_head res_list;
int ret;
INIT_LIST_HEAD(&res_list);
ret = acpi_dev_get_resources(adev, &res_list,
acpi_populate_gpio_lookup,
lookup);
if (ret < 0)
return ret;
acpi_dev_free_resource_list(&res_list);
if (!lookup->desc)
return -ENOENT;
if (info)
*info = lookup->info;
return 0;
}
static int acpi_gpio_property_lookup(struct fwnode_handle *fwnode,
const char *propname, int index,
struct acpi_gpio_lookup *lookup)
{
struct fwnode_reference_args args;
unsigned int quirks = 0;
int ret;
memset(&args, 0, sizeof(args));
ret = __acpi_node_get_property_reference(fwnode, propname, index, 3,
&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,
&quirks))
return ret;
}
/*
* The property was found and resolved, so need to lookup the GPIO based
* on returned args.
*/
if (!to_acpi_device_node(args.fwnode))
return -EINVAL;
if (args.nargs != 3)
return -EPROTO;
lookup->index = args.args[0];
lookup->pin_index = args.args[1];
lookup->active_low = !!args.args[2];
lookup->info.adev = to_acpi_device_node(args.fwnode);
lookup->info.quirks = quirks;
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.
*/
static 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 %u %u\n",
dev_name(&lookup.info.adev->dev), lookup.index,
lookup.pin_index, lookup.active_low);
} else {
dev_dbg(&adev->dev, "GPIO: looking up %d in _CRS\n", index);
lookup.info.adev = adev;
}
ret = acpi_gpio_resource_lookup(&lookup, info);
return ret ? ERR_PTR(ret) : lookup.desc;
}
static bool acpi_can_fallback_to_crs(struct acpi_device *adev,
const char *con_id)
{
/* Never allow fallback if the device has properties */
if (acpi_dev_has_props(adev) || adev->driver_gpios)
return false;
return con_id == NULL;
}
struct gpio_desc *acpi_find_gpio(struct device *dev,
const char *con_id,
unsigned int idx,
enum gpiod_flags *dflags,
unsigned long *lookupflags)
{
struct acpi_device *adev = ACPI_COMPANION(dev);
struct acpi_gpio_info info;
struct gpio_desc *desc;
char propname[32];
int i;
/* Try first from _DSD */
for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
if (con_id) {
snprintf(propname, sizeof(propname), "%s-%s",
con_id, gpio_suffixes[i]);
} else {
snprintf(propname, sizeof(propname), "%s",
gpio_suffixes[i]);
}
desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
if (!IS_ERR(desc))
break;
if (PTR_ERR(desc) == -EPROBE_DEFER)
return ERR_CAST(desc);
}
/* Then from plain _CRS GPIOs */
if (IS_ERR(desc)) {
if (!acpi_can_fallback_to_crs(adev, con_id))
return ERR_PTR(-ENOENT);
desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
if (IS_ERR(desc))
return desc;
}
if (info.gpioint &&
(*dflags == GPIOD_OUT_LOW || *dflags == GPIOD_OUT_HIGH)) {
dev_dbg(dev, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n");
return ERR_PTR(-ENOENT);
}
acpi_gpio_update_gpiod_flags(dflags, &info);
acpi_gpio_update_gpiod_lookup_flags(lookupflags, &info);
return 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 (i.e. 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.
*
* If the GPIO cannot be translated or there is an error an ERR_PTR is
* returned.
*/
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.
*
* The function is idempotent, though each time it runs it will configure GPIO
* pin direction according to the flags in GpioInt resource.
*
* 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;
int ret;
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);
/* Ignore -EPROBE_DEFER, it only matters if idx matches */
if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER)
return PTR_ERR(desc);
if (info.gpioint && idx++ == index) {
unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
enum gpiod_flags dflags = GPIOD_ASIS;
char label[32];
int irq;
if (IS_ERR(desc))
return PTR_ERR(desc);
irq = gpiod_to_irq(desc);
if (irq < 0)
return irq;
acpi_gpio_update_gpiod_flags(&dflags, &info);
acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
snprintf(label, sizeof(label), "GpioInt() %d", index);
ret = gpiod_configure_flags(desc, label, lflags, dflags);
if (ret < 0)
return ret;
ret = gpio_set_debounce_timeout(desc, info.debounce);
if (ret)
return ret;