linux-kernel - Re: [PATCH 06/16] ASoC: cs42l42: Reset GPIO is mandatory

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Date:   Fri, 15 Oct 2021 15:30:07 +0100
From:   Mark Brown <broonie@...nel.org>
To:     Richard Fitzgerald <rf@...nsource.cirrus.com>
Cc:     alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
        patches@...nsource.cirrus.com
Subject: Re: [PATCH 06/16] ASoC: cs42l42: Reset GPIO is mandatory

On Fri, Oct 15, 2021 at 02:36:09PM +0100, Richard Fitzgerald wrote:

> The hard RESET must be used to correctly power-up the cs42l42, as
> described in the datasheet.

> The code was getting the GPIO with devm_gpiod_get_optional(). Change
> this to devm_gpiod_get().

Does that power sequencing have to be done by the CPU though?  Usually
if a GPIO is not supplied it's because the sequencing is done during the
general power up sequence (PMICs can be programmed to assert GPIOs as
part of the their sequencing for example).

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