Add support for pull up/down to lineevent_create. Use cases include receiving asynchronous presses from a push button without an external pull up/down. Also restrict the application of bias to lines explicitly requested as inputs to prevent bias being applied to as-is line requests. Signed-off-by: Kent Gibson <warthog618@xxxxxxxxx> --- drivers/gpio/gpiolib.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index e80e689be2cc..7dfbb3676ee0 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -554,6 +554,12 @@ 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; @@ -944,6 +950,10 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip) if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW) set_bit(FLAG_ACTIVE_LOW, &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_direction_input(desc); if (ret) -- 2.23.0