diff options
| author | Drew Fustini <[email protected]> | 2019-09-21 12:25:23 +0200 |
|---|---|---|
| committer | Linus Walleij <[email protected]> | 2019-10-05 18:59:14 +0200 |
| commit | 8c550e94b8835170593169a45b5ba30d3fc72a70 (patch) | |
| tree | a58d4be1e471377362f15562a8146a5b76cd94c5 | |
| parent | 2a36550567307b881ce570a81189682ae1c9d08d (diff) | |
gpio: expose pull-up/pull-down line flags to userspace
Add pull-up/pull-down flags to the gpio line get and
set ioctl() calls. Use cases include a push button
that does not have an external resistor.
Addition use cases described by Limor Fried (ladyada) of
Adafruit in this PR for Adafruit_Blinka Python lib:
https://github.com/adafruit/Adafruit_Blinka/pull/59
Signed-off-by: Drew Fustini <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Linus Walleij <[email protected]>
| -rw-r--r-- | drivers/gpio/gpiolib.c | 12 | ||||
| -rw-r--r-- | include/uapi/linux/gpio.h | 4 |
2 files changed, 16 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 2342deaace17..921f76d2f5c4 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -421,6 +421,8 @@ struct linehandle_state { (GPIOHANDLE_REQUEST_INPUT | \ GPIOHANDLE_REQUEST_OUTPUT | \ GPIOHANDLE_REQUEST_ACTIVE_LOW | \ + GPIOHANDLE_REQUEST_PULL_UP | \ + GPIOHANDLE_REQUEST_PULL_DOWN | \ GPIOHANDLE_REQUEST_OPEN_DRAIN | \ GPIOHANDLE_REQUEST_OPEN_SOURCE) @@ -592,6 +594,10 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) set_bit(FLAG_OPEN_DRAIN, &desc->flags); if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE) set_bit(FLAG_OPEN_SOURCE, &desc->flags); + if (lflags & GPIOHANDLE_REQUEST_PULL_DOWN) + set_bit(FLAG_PULL_DOWN, &desc->flags); + if (lflags & GPIOHANDLE_REQUEST_PULL_UP) + set_bit(FLAG_PULL_UP, &desc->flags); ret = gpiod_set_transitory(desc, false); if (ret < 0) @@ -1097,6 +1103,10 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) lineinfo.flags |= (GPIOLINE_FLAG_OPEN_SOURCE | GPIOLINE_FLAG_IS_OUT); + if (test_bit(FLAG_PULL_DOWN, &desc->flags)) + lineinfo.flags |= GPIOLINE_FLAG_PULL_DOWN; + if (test_bit(FLAG_PULL_UP, &desc->flags)) + lineinfo.flags |= GPIOLINE_FLAG_PULL_UP; if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) return -EFAULT; @@ -2770,6 +2780,8 @@ static bool gpiod_free_commit(struct gpio_desc *desc) clear_bit(FLAG_REQUESTED, &desc->flags); clear_bit(FLAG_OPEN_DRAIN, &desc->flags); clear_bit(FLAG_OPEN_SOURCE, &desc->flags); + clear_bit(FLAG_PULL_UP, &desc->flags); + clear_bit(FLAG_PULL_DOWN, &desc->flags); clear_bit(FLAG_IS_HOGGED, &desc->flags); ret = true; } diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h index 4ebfe0ac6c5b..c2d1f7d908d6 100644 --- a/include/uapi/linux/gpio.h +++ b/include/uapi/linux/gpio.h @@ -33,6 +33,8 @@ struct gpiochip_info { #define GPIOLINE_FLAG_ACTIVE_LOW (1UL << 2) #define GPIOLINE_FLAG_OPEN_DRAIN (1UL << 3) #define GPIOLINE_FLAG_OPEN_SOURCE (1UL << 4) +#define GPIOLINE_FLAG_PULL_UP (1UL << 5) +#define GPIOLINE_FLAG_PULL_DOWN (1UL << 6) /** * struct gpioline_info - Information about a certain GPIO line @@ -62,6 +64,8 @@ struct gpioline_info { #define GPIOHANDLE_REQUEST_ACTIVE_LOW (1UL << 2) #define GPIOHANDLE_REQUEST_OPEN_DRAIN (1UL << 3) #define GPIOHANDLE_REQUEST_OPEN_SOURCE (1UL << 4) +#define GPIOHANDLE_REQUEST_PULL_UP (1UL << 5) +#define GPIOHANDLE_REQUEST_PULL_DOWN (1UL << 6) /** * struct gpiohandle_request - Information about a GPIO handle request |