unbind command
Synopsis
unbind <node path>
unbind <class> <seq>
unbind <class> <seq> <driver>
Description
The unbind command is used to unbind a device from a driver. This makes the device unavailable in U-Boot.
- node path
path of the device’s device-tree node
- class
device class name
- seq
sequence number of the 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 three alternative unbind syntaxes.
=> dm tree
Class Seq 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
=> dm tree
Class Seq Probed Driver Name
-----------------------------------------------------------
root 0 [ + ] root_driver root_driver
...
=> unbind /pl031@9010000
Cannot find a device with path /pl031@9010000
=> bind /pl031@9010000 rtc-pl031
=> dm tree
Class Seq Probed Driver Name
-----------------------------------------------------------
root 0 [ + ] root_driver root_driver
...
rtc 0 [ ] rtc-pl031 |-- pl031@9010000
=> unbind rtc 0
=> bind /pl031@9010000 rtc-pl031
=> unbind rtc 0 rtc-pl031
Configuration
The unbind command is only available if CONFIG_CMD_BIND=y.
Return code
The return code $? is 0 (true) on success and 1 (false) on failure.