gpiolib-acpi: Add ACPI5 event model support to gpio. (0d1c28a4) · Commits · 戴 / test

drivers/gpio/gpiolib-acpi.c

+82 −0

Original line number	Diff line number	Diff line
		@@ -15,6 +15,7 @@
		#include <linux/export.h>
		#include <linux/acpi_gpio.h>
		#include <linux/acpi.h>
		#include <linux/interrupt.h>

		static int acpi_gpiochip_find(struct gpio_chip gc, void data)
		{
		@@ -52,3 +53,84 @@ int acpi_get_gpio(char *path, int pin)
		return chip->base + pin;
		}
		EXPORT_SYMBOL_GPL(acpi_get_gpio);


		static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
		{
		acpi_handle handle = data;

		acpi_evaluate_object(handle, NULL, NULL, NULL);

		return IRQ_HANDLED;
		}

		/**
		* 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.
		*
		* Interrupts are automatically freed on driver detach
		*/

		void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
		{
		struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
		struct acpi_resource *res;
		acpi_handle handle, ev_handle;
		acpi_status status;
		unsigned int pin, irq;
		char ev_name[5];

		if (!chip->dev \|\| !chip->to_irq)
		return;

		handle = ACPI_HANDLE(chip->dev);
		if (!handle)
		return;

		status = acpi_get_event_resources(handle, &buf);
		if (ACPI_FAILURE(status))
		return;

		/* If a gpio interrupt has an acpi event handler method, then
		* set up an interrupt handler that calls the acpi event handler
		*/

		for (res = buf.pointer;
		res && (res->type != ACPI_RESOURCE_TYPE_END_TAG);
		res = ACPI_NEXT_RESOURCE(res)) {

		if (res->type != ACPI_RESOURCE_TYPE_GPIO \|\|
		res->data.gpio.connection_type !=
		ACPI_RESOURCE_GPIO_TYPE_INT)
		continue;

		pin = res->data.gpio.pin_table[0];
		if (pin > chip->ngpio)
		continue;

		sprintf(ev_name, "_%c%02X",
		res->data.gpio.triggering ? 'E' : 'L', pin);

		status = acpi_get_handle(handle, ev_name, &ev_handle);
		if (ACPI_FAILURE(status))
		continue;

		irq = chip->to_irq(chip, pin);
		if (irq < 0)
		continue;

		/* Assume BIOS sets the triggering, so no flags */
		devm_request_threaded_irq(chip->dev, irq, NULL,
		acpi_gpio_irq_handler,
		0,
		"GPIO-signaled-ACPI-event",
		ev_handle);
		}
		}
		EXPORT_SYMBOL(acpi_gpiochip_request_interrupts);

include/linux/acpi_gpio.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -2,10 +2,12 @@
		#define _LINUX_ACPI_GPIO_H_

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

		#ifdef CONFIG_GPIO_ACPI

		int acpi_get_gpio(char *path, int pin);
		void acpi_gpiochip_request_interrupts(struct gpio_chip *chip);

		#else /* CONFIG_GPIO_ACPI */

		@@ -14,6 +16,8 @@ static inline int acpi_get_gpio(char *path, int pin)
		return -ENODEV;
		}

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

		#endif /* CONFIG_GPIO_ACPI */

		#endif /* _LINUX_ACPI_GPIO_H_ */

Admin message