Re: [PATCH v4 2/2] ASoC: codecs: wsa883x: Handle shared reset GPIO for WSA883x speakers

[Srinivas Kandagatla <srini@kernel.org>]

On 8/6/25 7:18 PM, Mohammad Rafi Shaik wrote:
> From: Mohammad Rafi Shaik <quic_mohs@quicinc.com>
> 
> On some Qualcomm platforms such as QCS6490-RB3Gen2, the multiple
> WSA8830/WSA8835 speaker amplifiers share a common reset (shutdown) GPIO.
> 
> To handle such scenario, use the reset controller framework and its
> "reset-gpio" driver to handle such case. This allows proper handling
> of all WSA883x speaker amplifiers on QCS6490-RB3Gen2 board.
> 
> Signed-off-by: Mohammad Rafi Shaik <quic_mohs@quicinc.com>
> ---
>  sound/soc/codecs/wsa883x.c | 57 +++++++++++++++++++++++++++++++++-----
>  1 file changed, 50 insertions(+), 7 deletions(-)
> 
> diff --git a/sound/soc/codecs/wsa883x.c b/sound/soc/codecs/wsa883x.c
> index 188363b03b93..ec7a55d88576 100644
> --- a/sound/soc/codecs/wsa883x.c
> +++ b/sound/soc/codecs/wsa883x.c
> @@ -14,6 +14,7 @@
>  #include <linux/printk.h>
>  #include <linux/regmap.h>
>  #include <linux/regulator/consumer.h>
> +#include <linux/reset.h>
>  #include <linux/slab.h>
>  #include <linux/soundwire/sdw.h>
>  #include <linux/soundwire/sdw_registers.h>
> @@ -468,6 +469,7 @@ struct wsa883x_priv {
>  	struct sdw_stream_runtime *sruntime;
>  	struct sdw_port_config port_config[WSA883X_MAX_SWR_PORTS];
>  	struct gpio_desc *sd_n;
> +	struct reset_control *sd_reset;
>  	bool port_prepared[WSA883X_MAX_SWR_PORTS];
>  	bool port_enable[WSA883X_MAX_SWR_PORTS];
>  	int active_ports;
> @@ -1546,6 +1548,46 @@ static const struct hwmon_chip_info wsa883x_hwmon_chip_info = {
>  	.info	= wsa883x_hwmon_info,
>  };
>  
> +static void wsa883x_reset_assert(void *data)
> +{
> +	struct wsa883x_priv *wsa883x = data;
> +
> +	if (wsa883x->sd_reset)
> +		reset_control_assert(wsa883x->sd_reset);
> +	else
> +		gpiod_direction_output(wsa883x->sd_n, 1);
> +}
> +
> +static void wsa883x_reset_deassert(struct wsa883x_priv *wsa883x)
> +{
> +	if (wsa883x->sd_reset)
> +		reset_control_deassert(wsa883x->sd_reset);
> +	else
> +		gpiod_direction_output(wsa883x->sd_n, 0);
> +}
> +
> +static int wsa883x_get_reset(struct device *dev, struct wsa883x_priv *wsa883x)
> +{
> +	wsa883x->sd_reset = devm_reset_control_get_optional_shared_deasserted(dev, NULL);
why deasserted ? we are already doing wsa883x_reset_deassert(wsa883x)
just after calling this.

> +	if (IS_ERR(wsa883x->sd_reset))
> +		return dev_err_probe(dev, PTR_ERR(wsa883x->sd_reset),
> +				     "Failed to get reset\n");
> +	/*
> +	 * if sd_reset: NULL, so use the backwards compatible way for powerdown-gpios,
> +	 * which does not handle sharing GPIO properly.
> +	 */
> +	if (!wsa883x->sd_reset) {
> +		wsa883x->sd_n = devm_gpiod_get_optional(dev, "powerdown",
> +							GPIOD_FLAGS_BIT_NONEXCLUSIVE |
> +							GPIOD_OUT_HIGH);
> +		if (IS_ERR(wsa883x->sd_n))
> +			return dev_err_probe(dev, PTR_ERR(wsa883x->sd_n),
> +					     "Shutdown Control GPIO not found\n");
> +	}
> +
> +	return 0;
> +}
> +
>  static int wsa883x_probe(struct sdw_slave *pdev,
>  			 const struct sdw_device_id *id)
>  {
> @@ -1566,11 +1608,9 @@ static int wsa883x_probe(struct sdw_slave *pdev,
>  	if (ret)
>  		return dev_err_probe(dev, ret, "Failed to enable vdd regulator\n");
>  
> -	wsa883x->sd_n = devm_gpiod_get_optional(dev, "powerdown",
> -						GPIOD_FLAGS_BIT_NONEXCLUSIVE | GPIOD_OUT_HIGH);
> -	if (IS_ERR(wsa883x->sd_n)) {
> -		ret = dev_err_probe(dev, PTR_ERR(wsa883x->sd_n),
> -				    "Shutdown Control GPIO not found\n");
> +	ret = wsa883x_get_reset(dev, wsa883x);
> +	if (ret) {
> +		dev_dbg(dev, "Failed to get reset powerdown GPIO: %d\n", ret);
this is redundant we already have failure messages from wsa883x_get_reset().


--srini
>  		goto err;
>  	}
>  
> @@ -1595,11 +1635,14 @@ static int wsa883x_probe(struct sdw_slave *pdev,
>  	pdev->prop.simple_clk_stop_capable = true;
>  	pdev->prop.sink_dpn_prop = wsa_sink_dpn_prop;
>  	pdev->prop.scp_int1_mask = SDW_SCP_INT1_BUS_CLASH | SDW_SCP_INT1_PARITY;
> -	gpiod_direction_output(wsa883x->sd_n, 0);
> +
> +	wsa883x_reset_deassert(wsa883x);
> +	ret = devm_add_action_or_reset(dev, wsa883x_reset_assert, wsa883x);
> +	if (ret)
> +		return ret;
>  
>  	wsa883x->regmap = devm_regmap_init_sdw(pdev, &wsa883x_regmap_config);
>  	if (IS_ERR(wsa883x->regmap)) {
> -		gpiod_direction_output(wsa883x->sd_n, 1);
>  		ret = dev_err_probe(dev, PTR_ERR(wsa883x->regmap),
>  				    "regmap_init failed\n");
>  		goto err;