gpiolib-acpi: introduce acpi_get_gpio_by_index() helper (12028d2d) · Commits · 戴 / test

Documentation/acpi/enumeration.txt

+31 −1

Original line number	Diff line number	Diff line
		@@ -199,6 +199,8 @@ the device to the driver. For example:
		{
		Name (SBUF, ResourceTemplate()
		{
		...
		// Used to power on/off the device
		GpioIo (Exclusive, PullDefault, 0x0000, 0x0000,
		IoRestrictionOutputOnly, "\\_SB.PCI0.GPI0",
		0x00, ResourceConsumer,,)
		@@ -206,10 +208,20 @@ the device to the driver. For example:
		// Pin List
		0x0055
		}

		// Interrupt for the device
		GpioInt (Edge, ActiveHigh, ExclusiveAndWake, PullNone,
		0x0000, "\\_SB.PCI0.GPI0", 0x00, ResourceConsumer,,)
		{
		// Pin list
		0x0058
		}

		...

		Return (SBUF)
		}

		Return (SBUF)
		}

		These GPIO numbers are controller relative and path "\\_SB.PCI0.GPI0"
		@@ -220,6 +232,24 @@ The driver can do this by including <linux/acpi_gpio.h> and then calling
		acpi_get_gpio(path, gpio). This will return the Linux GPIO number or
		negative errno if there was no translation found.

		In a simple case of just getting the Linux GPIO number from device
		resources one can use acpi_get_gpio_by_index() helper function. It takes
		pointer to the device and index of the GpioIo/GpioInt descriptor in the
		device resources list. For example:

		int gpio_irq, gpio_power;
		int ret;

		gpio_irq = acpi_get_gpio_by_index(dev, 1, NULL);
		if (gpio_irq < 0)
		/* handle error */

		gpio_power = acpi_get_gpio_by_index(dev, 0, NULL);
		if (gpio_power < 0)
		/* handle error */

		/* Now we can use the GPIO numbers */

		Other GpioIo parameters must be converted first by the driver to be
		suitable to the gpiolib before passing them.

drivers/gpio/gpiolib-acpi.c

+77 −0

Original line number	Diff line number	Diff line
		@@ -201,6 +201,83 @@ void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
		}
		EXPORT_SYMBOL(acpi_gpiochip_request_interrupts);

		struct acpi_gpio_lookup {
		struct acpi_gpio_info info;
		int index;
		int gpio;
		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->gpio < 0) {
		const struct acpi_resource_gpio *agpio = &ares->data.gpio;

		lookup->gpio = acpi_get_gpio(agpio->resource_source.string_ptr,
		agpio->pin_table[0]);
		lookup->info.gpioint =
		agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
		}

		return 1;
		}

		/**
		* acpi_get_gpio_by_index() - get a GPIO number from device resources
		* @dev: pointer to a device to get GPIO from
		* @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
		* up a GpioIo/GpioInt resource, translates it to the Linux GPIO number,
		* 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 the GPIO cannot be translated or there is an error, negative errno is
		* returned.
		*
		* Note: if the GPIO resource has multiple entries in the pin list, this
		* function only returns the first.
		*/
		int acpi_get_gpio_by_index(struct device *dev, int index,
		struct acpi_gpio_info *info)
		{
		struct acpi_gpio_lookup lookup;
		struct list_head resource_list;
		struct acpi_device *adev;
		acpi_handle handle;
		int ret;

		if (!dev)
		return -EINVAL;

		handle = ACPI_HANDLE(dev);
		if (!handle \|\| acpi_bus_get_device(handle, &adev))
		return -ENODEV;

		memset(&lookup, 0, sizeof(lookup));
		lookup.index = index;
		lookup.gpio = -ENODEV;

		INIT_LIST_HEAD(&resource_list);
		ret = acpi_dev_get_resources(adev, &resource_list, acpi_find_gpio,
		&lookup);
		if (ret < 0)
		return ret;

		acpi_dev_free_resource_list(&resource_list);

		if (lookup.gpio >= 0 && info)
		*info = lookup.info;

		return lookup.gpio;
		}
		EXPORT_SYMBOL_GPL(acpi_get_gpio_by_index);

		/**
		* acpi_gpiochip_free_interrupts() - Free GPIO _EVT ACPI event interrupts.

include/linux/acpi_gpio.h

+17 −0

Original line number	Diff line number	Diff line
		#ifndef _LINUX_ACPI_GPIO_H_
		#define _LINUX_ACPI_GPIO_H_

		#include <linux/device.h>
		#include <linux/errno.h>
		#include <linux/gpio.h>

		/**
		* struct acpi_gpio_info - ACPI GPIO specific information
		* @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo
		*/
		struct acpi_gpio_info {
		bool gpioint;
		};

		#ifdef CONFIG_GPIO_ACPI

		int acpi_get_gpio(char *path, int pin);
		int acpi_get_gpio_by_index(struct device *dev, int index,
		struct acpi_gpio_info *info);
		void acpi_gpiochip_request_interrupts(struct gpio_chip *chip);
		void acpi_gpiochip_free_interrupts(struct gpio_chip *chip);

		@@ -17,6 +28,12 @@ static inline int acpi_get_gpio(char *path, int pin)
		return -ENODEV;
		}

		static inline int acpi_get_gpio_by_index(struct device *dev, int index,
		struct acpi_gpio_info *info)
		{
		return -ENODEV;
		}

		static inline void acpi_gpiochip_request_interrupts(struct gpio_chip *chip) { }
		static inline void acpi_gpiochip_free_interrupts(struct gpio_chip *chip) { }

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