From: Felipe Balbi <[email protected]> Few architectures, like OMAP, allow you to set a debouncing time for the gpio before generating the IRQ. Teach gpiolib about that.
Signed-off-by: Felipe Balbi <[email protected]> --- drivers/gpio/gpiolib.c | 43 +++++++++++++++++++++++++++++++++++++++++++ include/asm-generic/gpio.h | 5 +++++ include/linux/gpio.h | 5 +++++ 3 files changed, 53 insertions(+), 0 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index eb0c3fe..cd85fd1 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1447,6 +1447,49 @@ fail: } EXPORT_SYMBOL_GPL(gpio_direction_output); +/** + * gpio_set_debounce - sets @debounce time for a @gpio + * @gpio: the gpio to set debounce time + * @debounce: debounce time is microseconds + */ +int gpio_set_debounce(unsigned gpio, unsigned debounce) +{ + unsigned long flags; + struct gpio_chip *chip; + struct gpio_desc *desc = &gpio_desc[gpio]; + int status = -EINVAL; + + spin_lock_irqsave(&gpio_lock, flags); + + if (!gpio_is_valid(gpio)) + goto fail; + chip = desc->chip; + if (!chip || !chip->set || !chip->set_debounce) + goto fail; + gpio -= chip->base; + if (gpio >= chip->ngpio) + goto fail; + status = gpio_ensure_requested(desc, gpio); + if (status < 0) + goto fail; + + /* now we know the gpio is valid and chip won't vanish */ + + spin_unlock_irqrestore(&gpio_lock, flags); + + might_sleep_if(extra_checks && chip->can_sleep); + + return chip->set_debounce(chip, gpio, debounce); + +fail: + spin_unlock_irqrestore(&gpio_lock, flags); + if (status) + pr_debug("%s: gpio-%d status %d\n", + __func__, gpio, status); + + return status; +} +EXPORT_SYMBOL_GPL(gpio_set_debounce); /* I/O calls are only valid after configuration completed; the relevant * "is this a valid GPIO" error checks should already have been done. diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index 979c6a5..ce3eb87 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -88,6 +88,9 @@ struct gpio_chip { unsigned offset); int (*direction_output)(struct gpio_chip *chip, unsigned offset, int value); + int (*set_debounce)(struct gpio_chip *chip, + unsigned offset, unsigned debounce); + void (*set)(struct gpio_chip *chip, unsigned offset, int value); @@ -121,6 +124,8 @@ extern void gpio_free(unsigned gpio); extern int gpio_direction_input(unsigned gpio); extern int gpio_direction_output(unsigned gpio, int value); +extern int gpio_set_debounce(unsigned gpio, unsigned debounce); + extern int gpio_get_value_cansleep(unsigned gpio); extern void gpio_set_value_cansleep(unsigned gpio, int value); diff --git a/include/linux/gpio.h b/include/linux/gpio.h index 4e949a5..03f616b 100644 --- a/include/linux/gpio.h +++ b/include/linux/gpio.h @@ -51,6 +51,11 @@ static inline int gpio_direction_output(unsigned gpio, int value) return -ENOSYS; } +static inline int gpio_set_debounce(unsigned gpio, unsigned debounce) +{ + return -ENOSYS; +} + static inline int gpio_get_value(unsigned gpio) { /* GPIO can never have been requested or set as {in,out}put */ -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
