[PATCH v4 2/2] ASoC: cs35l41: Read System Name from ACPI _SUB to identify firmware

[Rafael J. Wysocki]

On Tue, Jun 28, 2022 at 12:44 PM Stefan Binding
<sbinding at opensource.cirrus.com> 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.
>
> Signed-off-by: Stefan Binding <sbinding at opensource.cirrus.com>
> ---
>  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..9ab016094b32 100644
> --- a/sound/soc/codecs/cs35l41.c
> +++ b/sound/soc/codecs/cs35l41.c
> @@ -6,6 +6,7 @@
>  //
>  // Author: David Rhodes <david.rhodes at cirrus.com>
>
> +#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_probe_acpi(struct cs35l41_private *cs35l41)

I'd call this cs35l41_acpi_get_name(), because that's what it does.

> +{
> +       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);
> +       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_probe_acpi(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);
>
> --