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.. SPDX-License-Identifier: GPL-2.0+:
.. index::
single: gpio (command)
gpio command
============
Synopsis
--------
::
gpio <input|set|clear|toggle> <pin>
gpio read <name> <pin>
gpio status [-a] [<bank>|<pin>]
The gpio command is used to access General Purpose Inputs/Outputs.
gpio input
----------
Switch the GPIO *pin* to input mode.
gpio set
--------
Switch the GPIO *pin* to output mode and set the signal to 1.
gpio clear
----------
Switch the GPIO *pin* to output mode and set the signal to 0.
gpio toggle
-----------
Switch the GPIO *pin* to output mode and reverse the signal state.
gpio read
---------
Read the signal state of the GPIO *pin* and save it in environment variable
*name*.
gpio status
-----------
Display the status of one or multiple GPIOs. By default only claimed GPIOs
are displayed.
gpio status command output fields are::
<name>: <function>: <value> [x] <label>
*function* can take the following values:
output
pin configured in gpio output, *value* indicates the pin's level
input
pin configured in gpio input, *value* indicates the pin's level
func
pin configured in alternate function, followed by *label*
which shows pinmuxing label.
unused
pin not configured
*[x]* or *[ ]* indicate respectively if the gpio is used or not.
*label* shows the gpio label.
Parameters
----------
-a
Display GPIOs irrespective of being claimed.
bank
Name of a bank of GPIOs to be displayed.
pin
Name of a single GPIO to be displayed or manipulated.
Examples
--------
Switch the status of a GPIO::
=> gpio set a5
gpio: pin a5 (gpio 133) value is 1
=> gpio clear a5
gpio: pin a5 (gpio 133) value is 0
=> gpio toggle a5
gpio: pin a5 (gpio 133) value is 1
=> gpio read myvar a5
gpio: pin a5 (gpio 133) value is 1
=> echo $myvar
1
=> gpio toggle a5
gpio: pin a5 (gpio 133) value is 0
=> gpio read myvar a5
gpio: pin a5 (gpio 133) value is 0
=> echo $myvar
0
Show the GPIO status::
=> gpio status
Bank GPIOA:
GPIOA1: func rgmii-0
GPIOA2: func rgmii-0
GPIOA7: func rgmii-0
GPIOA10: output: 0 [x] hdmi-transmitter@39.reset-gpios
GPIOA13: output: 1 [x] red.gpios
Bank GPIOB:
GPIOB0: func rgmii-0
GPIOB1: func rgmii-0
GPIOB2: func uart4-0
GPIOB7: input: 0 [x] mmc@58005000.cd-gpios
GPIOB11: func rgmii-0
Configuration
-------------
The *gpio* command is only available if CONFIG_CMD_GPIO=y.
The *gpio read* command is only available if CONFIG_CMD_GPIO_READ=y.
Return value
------------
If the command succeds the return value $? is set to 0. If an error occurs, the
return value $? is set to 1.
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