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.

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

Usage: gpiocdev [OPTIONS] <COMMAND>

Commands:
  chip      Get information about GPIO chips
  edges     Monitor GPIO lines for edge events
  get       Read the levels of GPIO lines
  line      Get information about GPIO lines (everything but levels)
  notify    Monitor lines for requests and changes to configuration state
  platform  Get information about the platform GPIO uAPI support
  set       Set the levels of GPIO 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
  -V, --version  Print version

Refer to the help for each subcommand for more details.

Example Usage

chip

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

line

$ gpiocdev line -c 1
gpiochip1 - 8 lines:
	line   0:	BT_ON         	output
	line   1:	WL_ON         	output
	line   2:	PWR_LED_OFF   	output active-low consumer=led1
	line   3:	GLOBAL_RESET  	output
	line   4:	VDD_SD_IO_SEL 	output consumer=vdd-sd-io
	line   5:	CAM_GPIO      	output consumer=cam1_regulator
	line   6:	SD_PWR_ON     	output consumer=sd_vcc_reg
	line   7:	SD_OC_N       	input

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

get

$ gpiocdev get RXD0 GPIO22
RXD0=active GPIO22=inactive

$ gpiocdev get --quoted RXD0 GPIO22
"RXD0"=active "GPIO22"=inactive

$ gpiocdev get --numeric RXD0 GPIO22
1 0

set

$ gpiocdev set GPIO22=active

$ gpiocdev set GPIO17=1

Interactive mode:

$ 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

$ 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

$ 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

plaftorm

$ gpiocdev platform
Kernel 5.4.237-yocto-standard
uAPI ABI v1 is supported.
uAPI ABI v2 is not supported by the kernel.

$ gpiocdev platform -v
Kernel 5.15.0-72-generic
Kernel does not support HTE (added in 5.19).
uAPI ABI v1 is supported.
uAPI ABI v2 is supported.

ABI compatibility

The cli supports both GPIO uAPI v1 and v2.

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. The --abi-version option can be used to force the use of a particular ABI.

libgpiod compatibility

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

The subcommands map to libgpiod tools as follows:

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

gpiocdev detect

is equivalent to

gpiocdev chip

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

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.