u-boot/doc/usage/cmd/bind.rst
Heinrich Schuchardt 63e23f239d doc: bind man-page
provide a man-page for the bind command

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
2023-06-23 15:53:10 +02:00

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.. SPDX-License-Identifier: GPL-2.0+:
bind command
============
Synopsis
--------
::
bind <node path> <driver>
bind <class> <index> <driver>
Description
-----------
The bind command is used to bind a device to a driver. This makes the
device available in U-Boot.
While binding to a *node path* typically provides a working device
binding by parent node and driver may lead to a device that is only
partially initialized.
node path
path of the device's device-tree node
class
device class name
index
index of the parent device in the device class
driver
device driver name
Example
-------
Given a system with a real time clock device with device path */pl031@9010000*
and using driver rtc-pl031 unbinding and binding of the device is demonstrated
using the two alternative bind syntaxes.
.. code-block::
=> dm tree
Class Index Probed Driver Name
-----------------------------------------------------------
root 0 [ + ] root_driver root_driver
...
rtc 0 [ ] rtc-pl031 |-- pl031@9010000
...
=> fdt addr $fdtcontroladdr
Working FDT set to 7ed7fdb0
=> fdt print
/ {
interrupt-parent = <0x00008003>;
model = "linux,dummy-virt";
#size-cells = <0x00000002>;
#address-cells = <0x00000002>;
compatible = "linux,dummy-virt";
...
pl031@9010000 {
clock-names = "apb_pclk";
clocks = <0x00008000>;
interrupts = <0x00000000 0x00000002 0x00000004>;
reg = <0x00000000 0x09010000 0x00000000 0x00001000>;
compatible = "arm,pl031", "arm,primecell";
};
...
}
=> unbind /pl031@9010000
=> date
Cannot find RTC: err=-19
=> dm tree
Class Index Probed Driver Name
-----------------------------------------------------------
root 0 [ + ] root_driver root_driver
...
=> bind /pl031@9010000 rtc-pl031
=> dm tree
Class Index Probed Driver Name
-----------------------------------------------------------
root 0 [ + ] root_driver root_driver
...
rtc 0 [ ] rtc-pl031 |-- pl031@9010000
=> date
Date: 2023-06-22 (Thursday) Time: 15:14:51
=> unbind rtc 0 rtc-pl031
=> bind root 0 rtc-pl031
=> date
Date: 1980-08-19 (Tuesday) Time: 14:45:30
Obviously the device is not initialized correctly by the last bind command.
Configuration
-------------
The bind command is only available if CONFIG_CMD_BIND=y.
Return code
-----------
The return code $? is 0 (true) on success and 1 (false) on failure.