gpiolib: gpio_to_irq() hooks

Add a new gpiolib mechanism: gpio_chip instances can provide mappings
between their (input) GPIOs and any associated IRQs.  This makes it easier
for platforms to support IRQs that are provided by board-specific external
chips instead of as part of their core (such as SOC-integrated GPIOs).

Also update the irq_to_gpio() description, saying to avoid it because it's
not always supported.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Brownell
2008-10-15 22:03:14 -07:00
committed by Linus Torvalds
parent 2f8d11971b
commit 0f6d504e73
3 changed files with 28 additions and 2 deletions

View File

@@ -1010,6 +1010,24 @@ int __gpio_cansleep(unsigned gpio)
}
EXPORT_SYMBOL_GPL(__gpio_cansleep);
/**
* __gpio_to_irq() - return the IRQ corresponding to a GPIO
* @gpio: gpio whose IRQ will be returned (already requested)
* Context: any
*
* This is used directly or indirectly to implement gpio_to_irq().
* It returns the number of the IRQ signaled by this (input) GPIO,
* or a negative errno.
*/
int __gpio_to_irq(unsigned gpio)
{
struct gpio_chip *chip;
chip = gpio_to_chip(gpio);
return chip->to_irq ? chip->to_irq(chip, gpio - chip->base) : -ENXIO;
}
EXPORT_SYMBOL_GPL(__gpio_to_irq);
/* There's no value in making it easy to inline GPIO calls that may sleep.