greybus: arche-apb-ctrl: Introduce ara,init-disable property for APB
New DT property "ara,init-disable" will allow user to disable APB1 or APB2 during boot and enable it only when needed through command prompt via sysfs interface. - To disable APB2 during boot, specify "ara,init-disable" property in respective APB node. - How to check the state # cat /sys/devices/arche_platform.*/apb*/state It should be 'off', if 'ara,init-disable' enabled in DT. - During runtime if user/developer desired to enable APB2 (strictly and only for development purpose) then respective APB can be enabled through, # echo active > /sys/devices/arche_platform.*/apb*/state Note: - If APB device is in 'off,disabled' state, then no state transitions are permitted. - User/developer must first activate APB device # echo active > /sys/devices/arche_platform.*/apb*/state This will clear the 'init-disable' flag and allow state transition from here onwards. Note that, 'off,disabled' is only indicative state and is only applicable during init/boot. Testing Done: Tested on EVT1.2 and DB3.5 platform Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Showing
Please register or sign in to comment