diff options
| -rw-r--r-- | Documentation/acpi/enumeration.txt | 32 | ||||
| -rw-r--r-- | drivers/gpio/gpiolib-acpi.c | 77 | ||||
| -rw-r--r-- | include/linux/acpi_gpio.h | 17 |
3 files changed, 125 insertions, 1 deletions
diff --git a/Documentation/acpi/enumeration.txt b/Documentation/acpi/enumeration.txt index 94a6561..b0d5410 100644 --- a/Documentation/acpi/enumeration.txt +++ b/Documentation/acpi/enumeration.txt @@ -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. diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index 89336c4..5c1ef2b 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -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. diff --git a/include/linux/acpi_gpio.h b/include/linux/acpi_gpio.h index 213135f..4c120a1 100644 --- a/include/linux/acpi_gpio.h +++ b/include/linux/acpi_gpio.h @@ -1,12 +1,23 @@ #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) { } |