[PATCH] gpio: expose gpio_to_chip()

From: Linus Walleij
Date: Thu Apr 14 2011 - 16:00:14 EST

This makes the gpio_to_chip() function available to drivers. The
usecase is when you want to add a few chip-specific operations
apart from the ones exposed in struct gpio_chip.

Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Grant, would be great to have your input on this.

I will need this for enabling/disabling IRQ in certain pins
and setting pullup/pulldown mode, setting sleep modes for pins
etc when migrating arch/arm/mach-u300/gpio.c and
arch/arm/plat-nomadik/gpio.c out from the arch/arm hierarchy
and into drivers/gpio where they belong.

An alternative solution is to implement generic function pointers
for these things in struct gpio_chip, which I'm happy to do.
Beware that it'll be quite a number of enumerators for all the
funky pullup/pulldown modes people have, and for the sleep modes

Linus Walleij
drivers/gpio/gpiolib.c | 2 +-
include/asm-generic/gpio.h | 1 +
2 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 36a2974..af219bd 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -112,7 +112,7 @@ static int gpio_ensure_requested(struct gpio_desc *desc, unsigned offset)

/* caller holds gpio_lock *OR* gpio is marked as requested */
-static inline struct gpio_chip *gpio_to_chip(unsigned gpio)
+struct gpio_chip *gpio_to_chip(unsigned gpio)
return gpio_desc[gpio].chip;
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index ff5c660..5a4d219 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -132,6 +132,7 @@ struct gpio_chip {

+extern struct gpio_chip *gpio_to_chip(unsigned gpio);
extern const char *gpiochip_is_requested(struct gpio_chip *chip,
unsigned offset);
extern int __must_check gpiochip_reserve(int start, int ngpio);

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