diff options
| -rw-r--r-- | drivers/gpio/gpiolib-acpi.c | 82 | ||||
| -rw-r--r-- | include/linux/acpi_gpio.h | 4 |
2 files changed, 86 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index cbad6e908d3..54ce2269ed2 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -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); diff --git a/include/linux/acpi_gpio.h b/include/linux/acpi_gpio.h index 91615a389b6..b76ebd08ff8 100644 --- a/include/linux/acpi_gpio.h +++ b/include/linux/acpi_gpio.h @@ -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_ */ |