[PATCH v2] ASoC: tas5805m: fix pdn polarity
John Keeping
john at metanate.com
Wed Mar 9 17:19:31 CET 2022
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.
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