Re: [PATCH 1/2] mfd: arizona: Add GPIO maintain state flag

From: Rob Herring
Date: Mon Apr 10 2017 - 16:18:04 EST


On Fri, Apr 07, 2017 at 01:38:44PM +0100, Charles Keepax wrote:
> The Arizona devices only maintain the state of output GPIOs whilst the
> CODEC is active, this can cause issues if the CODEC suspends whilst
> something is relying on the state of one of its GPIOs. However, in
> many systems the CODEC GPIOs are used for audio related features
> and thus the state of the GPIOs is unimportant whilst the CODEC is
> suspended. Often keeping the CODEC resumed in such a system would
> incur a power impact that is unacceptable.
>
> Add a flag through the second cell of the GPIO specifier in device
> tree, to allow the user to select whether a GPIO being configured as
> an output should keep the CODEC resumed.

If the whole codec can't be suspended, why does this need to be per
GPIO? You could just have a single boolean property.

>
> Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/mfd/arizona.txt | 5 ++++-
> include/dt-bindings/mfd/arizona.h | 3 +++
> 2 files changed, 7 insertions(+), 1 deletion(-)