diff options
| author |   Drew Fustini <drew@pdp7.com> | 2019-11-05 10:04:23 +0800 |
|---|---|---|
| committer |   Bartosz Golaszewski <bgolaszewski@baylibre.com> | 2019-11-12 16:30:30 +0100 |
| commit | 9225d5169d110734099a82c39c073a11e399cb3f (patch) | |
| tree | ce801bf8c51d4dc21533dca65d8c2f8d87562a2a /drivers/gpio | |
| parent | gpio: rcar: Use proper irq_chip name (diff) | |
| download | linux-dev-9225d5169d110734099a82c39c073a11e399cb3f.tar.xz linux-dev-9225d5169d110734099a82c39c073a11e399cb3f.zip | |
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 <drew@pdp7.com>
[Kent: added BIAS to GPIO flag names and restrict application to input
lines]
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 731d732cdc2b..53086724c051 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -422,6 +422,8 @@ struct linehandle_state { (GPIOHANDLE_REQUEST_INPUT | \ GPIOHANDLE_REQUEST_OUTPUT | \ GPIOHANDLE_REQUEST_ACTIVE_LOW | \ + GPIOHANDLE_REQUEST_BIAS_PULL_UP | \ + GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | \ GPIOHANDLE_REQUEST_OPEN_DRAIN | \ GPIOHANDLE_REQUEST_OPEN_SOURCE) @@ -553,6 +555,12 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))) return -EINVAL; + /* PULL_UP and PULL_DOWN flags only make sense for input mode. */ + if (!(lflags & GPIOHANDLE_REQUEST_INPUT) && + ((lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) || + (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN))) + return -EINVAL; + lh = kzalloc(sizeof(*lh), GFP_KERNEL); if (!lh) return -ENOMEM; @@ -593,6 +601,10 @@ 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_BIAS_PULL_DOWN) + set_bit(FLAG_PULL_DOWN, &desc->flags); + if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) + set_bit(FLAG_PULL_UP, &desc->flags); ret = gpiod_set_transitory(desc, false); if (ret < 0) @@ -1092,6 +1104,10 @@ 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_BIAS_PULL_DOWN; + if (test_bit(FLAG_PULL_UP, &desc->flags)) + lineinfo.flags |= GPIOLINE_FLAG_BIAS_PULL_UP; if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) return -EFAULT; @@ -2785,6 +2801,8 @@ 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; } |