From 9225d5169d110734099a82c39c073a11e399cb3f Mon Sep 17 00:00:00 2001 From: Drew Fustini Date: Tue, 5 Nov 2019 10:04:23 +0800 Subject: 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 [Kent: added BIAS to GPIO flag names and restrict application to input lines] Signed-off-by: Kent Gibson Signed-off-by: Bartosz Golaszewski --- include/uapi/linux/gpio.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h index 4ebfe0ac6c5b..39e6c7854d63 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_BIAS_PULL_UP (1UL << 5) +#define GPIOLINE_FLAG_BIAS_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_BIAS_PULL_UP (1UL << 5) +#define GPIOHANDLE_REQUEST_BIAS_PULL_DOWN (1UL << 6) /** * struct gpiohandle_request - Information about a GPIO handle request -- cgit From 2148ad7790ea4f1f0081e6404fbb776bdbc793bb Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Tue, 5 Nov 2019 10:04:25 +0800 Subject: gpiolib: add support for disabling line bias Allow pull up/down bias to be disabled, allowing the line to float or to be biased only by external circuitry. Use case is for where the bias has been applied previously, either by default or by the user, but that setting may conflict with the current use of the line. Signed-off-by: Kent Gibson Signed-off-by: Bartosz Golaszewski --- include/uapi/linux/gpio.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h index 39e6c7854d63..7cc21c3b0839 100644 --- a/include/uapi/linux/gpio.h +++ b/include/uapi/linux/gpio.h @@ -35,6 +35,7 @@ struct gpiochip_info { #define GPIOLINE_FLAG_OPEN_SOURCE (1UL << 4) #define GPIOLINE_FLAG_BIAS_PULL_UP (1UL << 5) #define GPIOLINE_FLAG_BIAS_PULL_DOWN (1UL << 6) +#define GPIOLINE_FLAG_BIAS_DISABLE (1UL << 7) /** * struct gpioline_info - Information about a certain GPIO line @@ -66,6 +67,7 @@ struct gpioline_info { #define GPIOHANDLE_REQUEST_OPEN_SOURCE (1UL << 4) #define GPIOHANDLE_REQUEST_BIAS_PULL_UP (1UL << 5) #define GPIOHANDLE_REQUEST_BIAS_PULL_DOWN (1UL << 6) +#define GPIOHANDLE_REQUEST_BIAS_DISABLE (1UL << 7) /** * struct gpiohandle_request - Information about a GPIO handle request -- cgit From e588bb1eae31be73fbec2b731be986a7c09635a4 Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Tue, 5 Nov 2019 10:04:29 +0800 Subject: gpio: add new SET_CONFIG ioctl() to gpio chardev Add the GPIOHANDLE_SET_CONFIG_IOCTL to the gpio chardev. The ioctl allows some of the configuration of a requested handle to be changed without having to release the line. The primary use case is the changing of direction for bi-directional lines. Based on initial work by Bartosz Golaszewski Signed-off-by: Kent Gibson Signed-off-by: Bartosz Golaszewski --- include/uapi/linux/gpio.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h index 7cc21c3b0839..799cf823d493 100644 --- a/include/uapi/linux/gpio.h +++ b/include/uapi/linux/gpio.h @@ -100,6 +100,24 @@ struct gpiohandle_request { int fd; }; +/** + * struct gpiohandle_config - Configuration for a GPIO handle request + * @flags: updated flags for the requested GPIO lines, such as + * GPIOHANDLE_REQUEST_OUTPUT, GPIOHANDLE_REQUEST_ACTIVE_LOW etc, OR:ed + * together + * @default_values: if the GPIOHANDLE_REQUEST_OUTPUT is set in flags, + * this specifies the default output value, should be 0 (low) or + * 1 (high), anything else than 0 or 1 will be interpreted as 1 (high) + * @padding: reserved for future use and should be zero filled + */ +struct gpiohandle_config { + __u32 flags; + __u8 default_values[GPIOHANDLES_MAX]; + __u32 padding[4]; /* padding for future use */ +}; + +#define GPIOHANDLE_SET_CONFIG_IOCTL _IOWR(0xB4, 0x0a, struct gpiohandle_config) + /** * struct gpiohandle_data - Information of values on a GPIO handle * @values: when getting the state of lines this contains the current -- cgit