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path: root/drivers/gpio/gpiolib-acpi.c
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-rw-r--r--drivers/gpio/gpiolib-acpi.c179
1 files changed, 162 insertions, 17 deletions
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index 05c6275da224..c3bdaff71c25 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -11,12 +11,14 @@
*/
#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"
@@ -55,6 +57,58 @@ static int acpi_gpiochip_find(struct gpio_chip *gc, void *data)
return ACPI_HANDLE(gc->dev) == 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 contigous 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")
@@ -69,6 +123,7 @@ 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))
@@ -78,10 +133,11 @@ static struct gpio_desc *acpi_get_gpiod(char *path, int pin)
if (!chip)
return ERR_PTR(-ENODEV);
- if (pin < 0 || pin > chip->ngpio)
- return ERR_PTR(-EINVAL);
+ offset = acpi_gpiochip_pin_to_gpio_offset(chip, pin);
+ if (offset < 0)
+ return ERR_PTR(offset);
- return gpiochip_get_desc(chip, pin);
+ return gpiochip_get_desc(chip, offset);
}
static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
@@ -287,9 +343,45 @@ void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
}
}
+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;
struct gpio_desc *desc;
int n;
};
@@ -303,13 +395,24 @@ static int acpi_find_gpio(struct acpi_resource *ares, void *data)
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[0]);
+ agpio->pin_table[pin_index]);
lookup->info.gpioint =
agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
- lookup->info.active_low =
- agpio->polarity == ACPI_ACTIVE_LOW;
+
+ /*
+ * 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.
+ */
+ if (lookup->info.gpioint)
+ lookup->info.active_low =
+ agpio->polarity == ACPI_ACTIVE_LOW;
}
return 1;
@@ -317,40 +420,79 @@ static int acpi_find_gpio(struct acpi_resource *ares, void *data)
/**
* acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
- * @dev: pointer to a device to get GPIO from
+ * @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 @dev and based on @index looks
+ * 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 device *dev, int index,
+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;
struct list_head resource_list;
- struct acpi_device *adev;
- acpi_handle handle;
+ bool active_low = false;
int ret;
- if (!dev)
- return ERR_PTR(-EINVAL);
-
- handle = ACPI_HANDLE(dev);
- if (!handle || acpi_bus_get_device(handle, &adev))
+ if (!adev)
return ERR_PTR(-ENODEV);
memset(&lookup, 0, sizeof(lookup));
lookup.index = index;
+ if (propname) {
+ struct acpi_reference_args args;
+
+ dev_dbg(&adev->dev, "GPIO: looking up %s\n", propname);
+
+ memset(&args, 0, sizeof(args));
+ ret = acpi_dev_get_property_reference(adev, propname,
+ index, &args);
+ if (ret) {
+ bool found = acpi_get_driver_gpio_data(adev, propname,
+ index, &args);
+ if (!found)
+ return ERR_PTR(ret);
+ }
+
+ /*
+ * The property was found and resolved so need to
+ * lookup the GPIO based on returned args instead.
+ */
+ 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)
+ active_low = !!args.args[2];
+ }
+
+ dev_dbg(&adev->dev, "GPIO: _DSD returned %s %zd %llu %llu %llu\n",
+ dev_name(&adev->dev), args.nargs,
+ args.args[0], args.args[1], args.args[2]);
+ } else {
+ dev_dbg(&adev->dev, "GPIO: looking up %d in _CRS\n", index);
+ }
+
INIT_LIST_HEAD(&resource_list);
ret = acpi_dev_get_resources(adev, &resource_list, acpi_find_gpio,
&lookup);
@@ -359,8 +501,11 @@ struct gpio_desc *acpi_get_gpiod_by_index(struct device *dev, int index,
acpi_dev_free_resource_list(&resource_list);
- if (lookup.desc && info)
+ if (lookup.desc && info) {
*info = lookup.info;
+ if (active_low)
+ info->active_low = active_low;
+ }
return lookup.desc ? lookup.desc : ERR_PTR(-ENOENT);
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.