Re: [PATCH 2/3] ASoC: codec: wcd938x: Convert to GPIO descriptors

[Johan Hovold <johan@kernel.org>]

On Sun, Mar 23, 2025 at 10:40:51PM -0500, Steev Klimaszewski wrote:
> On Sun, Mar 23, 2025 at 9:28 PM Peng Fan (OSS) <peng.fan@oss.nxp.com> wrote:
> >
> > From: Peng Fan <peng.fan@nxp.com>
> >
> > of_gpio.h is deprecated, update the driver to use GPIO descriptors.
> >  - Use dev_gpiod_get to get GPIO descriptor.
> >  - Use gpiod_set_value to configure output value.
> >
> > With legacy of_gpio API, the driver set gpio value 0 to assert reset,
> > and 1 to deassert reset. And the reset-gpios use GPIO_ACTIVE_LOW flag in
> > DTS, so set GPIOD_ASIS when get GPIO descriptors, and set value 1 means
> > output low, set value 0 means output high with gpiod API.
> >
> > Signed-off-by: Peng Fan <peng.fan@nxp.com>

> > @@ -3251,9 +3250,9 @@ static int wcd938x_populate_dt_data(struct wcd938x_priv *wcd938x, struct device
> >         struct wcd_mbhc_config *cfg = &wcd938x->mbhc_cfg;
> >         int ret;
> >
> > -       wcd938x->reset_gpio = of_get_named_gpio(dev->of_node, "reset-gpios", 0);
> > -       if (wcd938x->reset_gpio < 0)
> > -               return dev_err_probe(dev, wcd938x->reset_gpio,
> > +       wcd938x->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_ASIS);
> > +       if (IS_ERR(wcd938x->reset_gpio))
> > +               return dev_err_probe(dev, PTR_ERR(wcd938x->reset_gpio),
> >                                      "Failed to get reset gpio\n");
> >
> >         wcd938x->us_euro_gpio = devm_gpiod_get_optional(dev, "us-euro",
> > @@ -3297,10 +3296,10 @@ static int wcd938x_populate_dt_data(struct wcd938x_priv *wcd938x, struct device
> >
> >  static int wcd938x_reset(struct wcd938x_priv *wcd938x)
> >  {
> > -       gpio_direction_output(wcd938x->reset_gpio, 0);
> > +       gpiod_set_value(wcd938x->reset_gpio, 1);

This may be what is causing the regression; the driver no longer
configures the reset line as an output. From the docs:

	* GPIOD_ASIS or 0 to not initialize the GPIO at all. The
	  direction must be set later with one of the dedicated
	  functions.

> >         /* 20us sleep required after pulling the reset gpio to LOW */
> >         usleep_range(20, 30);
> > -       gpio_set_value(wcd938x->reset_gpio, 1);
> > +       gpiod_set_value(wcd938x->reset_gpio, 0);
> >         /* 20us sleep required after pulling the reset gpio to HIGH */
> >         usleep_range(20, 30);

> With this patchset applied, the wcd938x codec used in the Thinkpad
> X13s stops working:
> 
> wcd938x_codec audio-codec: soundwire device init timeout
> wcd938x_codec audio-codec: ASoC: error at snd_soc_component_probe on
> audio-codec: -110
> snd-sc8280xp sound: ASoC: failed to instantiate card -110
> snd-sc8280xp sound: probe with driver snd-sc8280xp failed with error -110

Johan