linux-kernel - Re: [PATCH v3 3/9] ASoC: codec: cs42l56: Convert to GPIO descriptors

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Message-ID: <CACRpkdbFASLw+Sr6Uofa_F+csmETa8h=YhDWkZOfF1x2fq9dOg@mail.gmail.com>
Date: Tue, 13 May 2025 14:54:55 +0200
From: Linus Walleij <linus.walleij@...aro.org>
To: "Peng Fan (OSS)" <peng.fan@....nxp.com>
Cc: David Rhodes <david.rhodes@...rus.com>, Richard Fitzgerald <rf@...nsource.cirrus.com>, 
	Liam Girdwood <lgirdwood@...il.com>, Mark Brown <broonie@...nel.org>, 
	Jaroslav Kysela <perex@...ex.cz>, Takashi Iwai <tiwai@...e.com>, Bartosz Golaszewski <brgl@...ev.pl>, 
	Charles Keepax <ckeepax@...nsource.cirrus.com>, linux-sound@...r.kernel.org, 
	patches@...nsource.cirrus.com, linux-kernel@...r.kernel.org, 
	linux-gpio@...r.kernel.org, Peng Fan <peng.fan@....com>
Subject: Re: [PATCH v3 3/9] ASoC: codec: cs42l56: Convert to GPIO descriptors

On Tue, May 6, 2025 at 9:31 AM Peng Fan (OSS) <peng.fan@....nxp.com> wrote:

> From: Peng Fan <peng.fan@....com>
>
> of_gpio.h is deprecated, update the driver to use GPIO descriptors.
>  - Use devm_gpiod_get_optional to get GPIO descriptor with default
>    polarity GPIOD_OUT_LOW, set consumer name.
>  - Use gpiod_set_value_cansleep to configure output value.
>
> Checking the current driver using legacy GPIO API, the
> nreset value is first output HIGH, then LOW, then HIGH.
>
> Checking the datasheet, nreset is should be held low after power
> on, when nreset is high, it starts to work.
>
> Since the driver has been here for quite long time and no complain on
> the nreset flow, still follow original flow when using GPIOD
> descriptors.
>
> Commit 944004eb56dc ("gpiolib: of: add a quirk for reset line for Cirrus
> CS42L56 codec") added quirks, so the gpio request API will work as before.
>
> Per datasheet, the DTS polarity should be GPIOD_ACTIVE_LOW. The binding
> example use value 0(GPIOD_ACTIVE_HIGH) which seems wrong. There is
> no in-tree DTS has the device, so all should be fine.
>
> Signed-off-by: Peng Fan <peng.fan@....com>

Reviewed-by: Linus Walleij <linus.walleij@...aro.org>

Yours,
Linus Walleij