gpiocdev-cli

A command line tool to access and control GPIO lines on Linux.

This is equivalent to the tools provided by libgpiod, combined into a single tool.

```text $ gpiocdev -h A utility to control GPIO lines on Linux using GPIO character devices.

Usage: gpiocdev [OPTIONS]

Commands: chip Get info about GPIO chips edges Monitor lines for edge events get Read the values of lines line Get information for lines notify Monitor lines for requests and changes to configuration state set Set the value of lines help Print this message or the help of the given subcommand(s)

Options: -v, --verbose Provide more detailed error messages -h, --help Print help information -V, --version Print version information ```

Refer to the help for each subcommand for more details.

Example Usage

chip

shell $ gpiocdev chip gpiochip0 [pinctrl-bcm2711] (58 lines) gpiochip1 [raspberrypi-exp-gpio] (8 lines)

line

```shell $ gpiocdev line -c 1 gpiochip1 - 8 lines: line 0: BTON output line 1: WLON output line 2: PWRLEDOFF output active-low consumer=led1 line 3: GLOBALRESET output line 4: VDDSDIOSEL output consumer=vdd-sd-io line 5: CAMGPIO output consumer=cam1regulator line 6: SDPWRON output consumer=sdvccreg line 7: SDOCN input

$ gpiocdev line RXD0 GPIO22 WLON gpiochip0 22 GPIO22 input gpiochip0 33 RXD0 input gpiochip1 1 WLON output ```

get

```shell $ gpiocdev get RXD0 GPIO22 RXD0=active GPIO22=inactive

$ gpiocdev get --numeric RXD0 GPIO22 1 0 ```

set

```shell $ gpiocdev set GPIO22=active

$ gpiocdev set GPIO17=1 ```

Interactive mode:

shell $ gpiocdev set -i GPIO23=1 GPIO24=0 gpiocdev-set> get GPIO23=active GPIO24=inactive gpiocdev-set> toggle gpiocdev-set> get GPIO23=inactive GPIO24=active gpiocdev-set> toggle GPIO23 gpiocdev-set> get GPIO23=active GPIO24=active gpiocdev-set> set GPIO24=0 gpiocdev-set> get GPIO23=active GPIO24=inactive gpiocdev-set> exit

edges

```shell $ gpiocdev edges GPIO22 264.429997058 rising GPIO22 270.948800095 falling GPIO22 279.482197087 rising GPIO22

$ gpiocdev edges --localtime GPIO22 2022-10-10T08:01:59.078908766 falling GPIO22 2022-10-10T08:01:59.810733200 rising GPIO22 2022-10-10T08:02:00.497461672 falling GPIO22 ```

notify

```shell $ gpiocdev notify GPIO23 390.467444514 requested GPIO23 390.467655548 released GPIO23 391.701420722 requested GPIO23 391.701624886 released GPIO23

$ gpiocdev notify --localtime GPIO23 2022-10-10T08:03:35.365989261 requested GPIO23 2022-10-10T08:03:35.366200648 released GPIO23 2022-10-10T08:03:35.884780936 requested GPIO23 2022-10-10T08:03:35.884881408 released GPIO23 ```

ABI compatibility

The cli supports both GPIO uAPI v1 and v2 through features.

Options that require v2, such as debounce, will fail if applied to a kernel that only supports v1.

Either or both uAPI versions can be supported in the one executable. By default both are supported, with the most recent ABI supported by the kernel being used.

libgpiod compatibility

The tools are plug compatible with the proposed tools for libgpiod v2, though unlike those can also work with both GPIO uAPI v1 and v2.

The subcommands map to libgpiod tools as follows: | Subcommand | libgpiod Tool | Alias | |------------|------|-------| | chip | gpiodetect | detect | | edges | gpiomon | mon | | get | gpioget | - | | line | gpioinfo | info | | notify | gpiowatch | watch | |set | gpioset | - |

The subcommand aliases provide an alternative drawn from the libgpiod tool name, minus the gpio prefix. e.g.

shell gpiocdev detect

is equivalent to

shell gpiocdev chip

The libgpiod v1 gpiofind tool is obsoleted by the line subcommand.