1 .. SPDX-License-Identifier: GPL-2.0+
17 The button command is used to retrieve the status of a button. To show the
18 status of a button with name 'button1' you would issue the command
24 The status of the button is both written to the console as *ON* or *OFF* and
25 set in the return value variable *$?* as 0 (true) or 1 (false). To retrieve
26 the status of a button with name *button1* and to write it to environment
27 variable *status1* you would execute the commands
34 A list of all available buttons and their status can be displayed using
40 If a button device has not been probed yet, its status will be shown as
41 *<inactive>* in the list.
46 To use the button command you must specify CONFIG_CMD_BUTTON=y and enable a
47 button driver. The available buttons are defined in the device-tree.
52 The variable *$?* takes the following values
54 +---+-----------------------------+
55 | 0 | ON, the button is pressed |
56 +---+-----------------------------+
57 | 1 | OFF, the button is released |
58 +---+-----------------------------+
59 | 0 | button list was shown |
60 +---+-----------------------------+
61 | 1 | button not found |
62 +---+-----------------------------+
63 | 1 | invalid arguments |
64 +---+-----------------------------+