Re: [PATCH v5 2/2] ASoC: cs35l41: Read System Name from ACPI _SUB to identify firmware

[Pierre-Louis Bossart]

On 6/30/22 10:01, Stefan Binding wrote:
> When loading firmware, wm_adsp uses a number of parameters to
> determine the path of the firmware and tuning files to load.
> One of these parameters is system_name.
> Add support in cs35l41 to read this system name from the ACPI
> _SUB ID in order to uniquely identify the firmware and tuning
> mapped to a particular system.

It's my understanding that the _SUB method is optional, not required. It
may be wise to plan for a fallback, e.g to use DMI quirks or other
identifiers, no?

If it's used quite widely, then it may be a good thing to add to
'alsa-info'.
> Signed-off-by: Stefan Binding <sbinding@xxxxxxxxxxxxxxxxxxxxx>
> ---
>  sound/soc/codecs/cs35l41.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> diff --git a/sound/soc/codecs/cs35l41.c b/sound/soc/codecs/cs35l41.c
> index 8766e19d85f1..d70469686699 100644
> --- a/sound/soc/codecs/cs35l41.c
> +++ b/sound/soc/codecs/cs35l41.c
> @@ -6,6 +6,7 @@
>  //
>  // Author: David Rhodes <david.rhodes@xxxxxxxxxx>
>  
> +#include <linux/acpi.h>
>  #include <linux/delay.h>
>  #include <linux/err.h>
>  #include <linux/init.h>
> @@ -1142,6 +1143,24 @@ static int cs35l41_dsp_init(struct cs35l41_private *cs35l41)
>  	return ret;
>  }
>  
> +static int cs35l41_acpi_get_name(struct cs35l41_private *cs35l41)
> +{
> +	acpi_handle handle = ACPI_HANDLE(cs35l41->dev);
> +	const char *sub;
> +
> +	/* If there is no ACPI_HANDLE, there is no ACPI for this system, return 0 */
> +	if (!handle)
> +		return 0;
> +
> +	sub = acpi_get_subsystem_id(handle);
> +	if (IS_ERR(sub))
> +		return PTR_ERR(sub);
> +
> +	cs35l41->dsp.system_name = sub;
> +	dev_dbg(cs35l41->dev, "Susystem ID: %s\n", cs35l41->dsp.system_name);

Typo: Subsystem

> +	return 0;
> +}
> +
>  int cs35l41_probe(struct cs35l41_private *cs35l41, const struct cs35l41_hw_cfg *hw_cfg)
>  {
>  	u32 regid, reg_revid, i, mtl_revid, int_status, chipid_match;
> @@ -1270,6 +1289,10 @@ int cs35l41_probe(struct cs35l41_private *cs35l41, const struct cs35l41_hw_cfg *
>  		goto err;
>  	}
>  
> +	ret = cs35l41_acpi_get_name(cs35l41);
> +	if (ret < 0)
> +		goto err;
> +
>  	ret = cs35l41_dsp_init(cs35l41);
>  	if (ret < 0)
>  		goto err;
> @@ -1316,6 +1339,7 @@ void cs35l41_remove(struct cs35l41_private *cs35l41)
>  	pm_runtime_disable(cs35l41->dev);
>  
>  	regmap_write(cs35l41->regmap, CS35L41_IRQ1_MASK1, 0xFFFFFFFF);
> +	kfree(cs35l41->dsp.system_name);
>  	wm_adsp2_remove(&cs35l41->dsp);
>  	cs35l41_safe_reset(cs35l41->regmap, cs35l41->hw_cfg.bst_type);
>