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

From: Johan Hovold
Date: Mon Mar 24 2025 - 04:13:31 EST


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@xxxxxxxxxxx> wrote:
> >
> > From: Peng Fan <peng.fan@xxxxxxx>
> >
> > 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@xxxxxxx>

> > @@ -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