From 35e8bb5175c1a6ff6253f1a2acb30bfe52a2f500 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Wed, 15 Oct 2008 22:03:16 -0700 Subject: gpiolib: request/free hooks Add a new internal mechanism to gpiolib to support low power operations by letting gpio_chip instances see when their GPIOs are in use. When no GPIOs are active, chips may be able to enter lower powered runtime states by disabling clocks and/or power domains. Signed-off-by: David Brownell Cc: "Magnus Damm" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-generic/gpio.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include') diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index 04cb1d175df1..81797ec9ab29 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -35,6 +35,10 @@ struct module; * @label: for diagnostics * @dev: optional device providing the GPIOs * @owner: helps prevent removal of modules exporting active GPIOs + * @request: optional hook for chip-specific activation, such as + * enabling module power and clock; may sleep + * @free: optional hook for chip-specific deactivation, such as + * disabling module power and clock; may sleep * @direction_input: configures signal "offset" as input, or returns error * @get: returns value for signal "offset"; for output signals this * returns either the value actually sensed, or zero @@ -67,6 +71,11 @@ struct gpio_chip { struct device *dev; struct module *owner; + int (*request)(struct gpio_chip *chip, + unsigned offset); + void (*free)(struct gpio_chip *chip, + unsigned offset); + int (*direction_input)(struct gpio_chip *chip, unsigned offset); int (*get)(struct gpio_chip *chip, -- cgit v1.2.2