diff options
| author | Kent Gibson <warthog618@gmail.com> | 2020-09-28 08:27:59 +0800 |
|---|---|---|
| committer | Bartosz Golaszewski <bgolaszewski@baylibre.com> | 2020-09-30 10:57:04 +0200 |
| commit | 65cff70464068a823b3f4a28074000febdce0630 (patch) | |
| tree | b262f306a48ef52165fd1a10b94fbd6673a73a38 /drivers/gpio/gpiolib.c | |
| parent | 7b8e00d981680ddbbdd9874a7b46e0da58a2da4b (diff) | |
gpiolib: cdev: support setting debounce
Add support for setting debounce on a line via the GPIO uAPI.
Where debounce is not supported by hardware, a software debounce is
provided.
The implementation of the software debouncer waits for the line to be
stable for the debounce period before determining if a level change,
and a corresponding edge event, has occurred. This provides maximum
protection against glitches, but also introduces a debounce_period
latency to edge events.
The software debouncer is integrated with the edge detection as it
utilises the line interrupt, and integration is simpler than getting
the two to interwork. Where software debounce AND edge detection is
required, the debouncer provides both.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index aa20481e9452..3cdf9effc13a 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2098,6 +2098,9 @@ static bool gpiod_free_commit(struct gpio_desc *desc) #ifdef CONFIG_OF_DYNAMIC desc->hog = NULL; #endif +#ifdef CONFIG_GPIO_CDEV + WRITE_ONCE(desc->debounce_period_us, 0); +#endif ret = true; } |