On Wed, Mar 09, 2022 at 03:56:12PM +0000, Mark Brown wrote:
On Wed, Mar 09, 2022 at 01:56:49PM +0000, John Keeping wrote:
The binding defines the GPIO as "pdn-gpios" so when the GPIO is active the expectation is that the power down signal is asserted and this is how all other drivers using this GPIO name interpret the value.
But the tas5805m driver inverts the sense from the normal expectation so when the powerdown GPIO is logically asserted the chip is running.
This is a new driver that is not yet in a released kernel and has no in-tree users of the binding so fix the sense of the GPIO so that logically asserted means that the device is powered down.
- Rewrite commit message to make it more obvious that this is a change to the interpretation of the GPIO in the binding
I'm still not seeing the functional change here. The actual state of the GPIO is identical in both cases, all that's changing is the logical view internally to the kernel.
Ah, sorry, I'm considering it functional since it changes the device tree ABI.
Used with the same device tree with, say, GPIO_ACTIVE_HIGH the physical state of the GPIO will change as a result of this patch and the device tree needs to be updated to use GPIO_ACTIVE_LOW.