Re: [PATCH v2 4/5] ASoC: codecs: wcd938x: add mux control support for hp audio mux

[Dmitry Baryshkov]

On Thu, Mar 20, 2025 at 11:56:32AM +0000, srinivas.kandagatla@xxxxxxxxxx wrote:
> From: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> 
> On some platforms to minimise pop and click during switching between
> CTIA and OMTP headset an additional HiFi mux is used. Most common
> case is that this switch is switched on by default, but on some
> platforms this needs a regulator enable.
> 
> move to using mux control to enable both regulator and handle gpios,
> deprecate the usage of gpio.
> 
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> ---
>  sound/soc/codecs/Kconfig   |  2 ++
>  sound/soc/codecs/wcd938x.c | 38 ++++++++++++++++++++++++++++++--------
>  2 files changed, 32 insertions(+), 8 deletions(-)
> 
> diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
> index ee35f3aa5521..b04076282c8b 100644
> --- a/sound/soc/codecs/Kconfig
> +++ b/sound/soc/codecs/Kconfig
> @@ -2226,6 +2226,8 @@ config SND_SOC_WCD938X
>  	tristate
>  	depends on SOUNDWIRE || !SOUNDWIRE
>  	select SND_SOC_WCD_CLASSH
> +	select MULTIPLEXER
> +	imply MUX_GPIO

Why? This is true for a particular platform, isn't it?

>  
>  config SND_SOC_WCD938X_SDW
>  	tristate "WCD9380/WCD9385 Codec - SDW"
> diff --git a/sound/soc/codecs/wcd938x.c b/sound/soc/codecs/wcd938x.c
> index f2a4f3262bdb..b7a235eef6ba 100644
> --- a/sound/soc/codecs/wcd938x.c
> +++ b/sound/soc/codecs/wcd938x.c
> @@ -19,6 +19,7 @@
>  #include <linux/regmap.h>
>  #include <sound/soc.h>
>  #include <sound/soc-dapm.h>
> +#include <linux/mux/consumer.h>
>  #include <linux/regulator/consumer.h>
>  
>  #include "wcd-clsh-v2.h"
> @@ -178,6 +179,8 @@ struct wcd938x_priv {
>  	int variant;
>  	int reset_gpio;
>  	struct gpio_desc *us_euro_gpio;
> +	struct mux_control *us_euro_mux;
> +	u32 mux_state;
>  	u32 micb1_mv;
>  	u32 micb2_mv;
>  	u32 micb3_mv;
> @@ -3243,9 +3246,16 @@ static bool wcd938x_swap_gnd_mic(struct snd_soc_component *component, bool activ
>  
>  	wcd938x = snd_soc_component_get_drvdata(component);
>  
> -	value = gpiod_get_value(wcd938x->us_euro_gpio);
> +	if (!wcd938x->us_euro_mux) {
> +		value = gpiod_get_value(wcd938x->us_euro_gpio);
>  
> -	gpiod_set_value(wcd938x->us_euro_gpio, !value);
> +		gpiod_set_value(wcd938x->us_euro_gpio, !value);

This looks like a separate topic, but why is 'active' being ignored?

> +	} else {
> +		mux_control_deselect(wcd938x->us_euro_mux);
> +		wcd938x->mux_state = !wcd938x->mux_state;
> +		if (mux_control_select(wcd938x->us_euro_mux, wcd938x->mux_state))

Can't it just be 'mux_control_select(wcd938x->us_euro_mux, active)' ?

> +			dev_err(component->dev, "Unable to select us/euro mux state\n");
> +	}
>  
>  	return true;
>  }

-- 
With best wishes
Dmitry