[PATCH v2 07/21] ASoC: ops: Introduce 'soc_set_enum_kctl'

[Cezary Rojewski]

On 10/4/2026 8:03 AM, James Calligeros wrote:
> From: Martin Povišer <povik+lin at cutebit.org>
> 
> The new function is to be used to set enumerated controls to desired
> values. It is something a machine driver may call in fixup_controls.

> +++ b/sound/soc/soc-ops.c
> @@ -505,6 +505,75 @@ int snd_soc_deactivate_kctl(struct snd_soc_card *card,
>  }
>  EXPORT_SYMBOL_GPL(snd_soc_deactivate_kctl);
>  
> +static int soc_set_enum_kctl(struct snd_kcontrol *kctl, const char *value)
> +{
> +	struct snd_ctl_elem_value evalue = { 0 };
> +	struct snd_ctl_elem_info info = { 0 };
> +	int sel, i, ret;
> +
> +	ret = kctl->info(kctl, &info);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (info.type != SNDRV_CTL_ELEM_TYPE_ENUMERATED)
> +		return -EINVAL;
> +
> +	for (sel = 0; sel < info.value.enumerated.items; sel++) {
> +		info.value.enumerated.item = sel;
> +		ret = kctl->info(kctl, &info);
> +		if (ret < 0)
> +			return ret;
> +
> +		if (!strcmp(value, info.value.enumerated.name))
> +			break;
> +	}
> +
> +	if (sel == info.value.enumerated.items)
> +		return -EINVAL;

ENOENT may be a better candidate.

> +
> +	for (i = 0; i < info.count; i++)
> +		evalue.value.enumerated.item[i] = sel;
> +
> +	if (kctl->put)
> +		return kctl->put(kctl, &evalue);
> +	else
> +		return -EINVAL;

The if-else statement is redundant here, drop the 'else' part. If fact,
it would be better to check for ->put() upfront rather than when all of
this iterating is done.

> +}
> +
> +/**
> + * snd_soc_set_enum_kctl - Set enumerated control matching a name
> + *
> + * @card: where to look for the controls
> + * @name: name
> + * @value: string value to set the controls to
> + *
> + * Return 0 on success, else error.
> + */
> +int snd_soc_set_enum_kctl(struct snd_soc_card *card,
> +	const char *name, const char *value)
> +{
> +	struct snd_kcontrol *kctl;
> +	int ret = -EINVAL;
> +
> +	/* Sanity check for name */
> +	if (unlikely(!name))
> +		return -EINVAL;

I'd leave the validation job to snd_soc_card_get_kcontrol().

> +
> +	kctl = snd_soc_card_get_kcontrol(card, name);
> +
> +	if (kctl) {
> +		ret = soc_set_enum_kctl(kctl, value);
> +		if (ret)
> +			return ret;

The if-statement is redundant.

> +	} else {
> +		dev_dbg(card->dev, "Tried to set unknown control '%s' to '%s'\n",
> +			name, value);

One line.

Maybe just refactor the entire block:

	kctl = snd_soc_card_get_kcontrol(..)
	if (!kctl) {
		dev_dbg(...);
		return -EINVAL;
	}

	return snd_set_enum_kctl(...);

With that, drop the assignment for 'ret' in the declaration block.

> +	}
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(snd_soc_set_enum_kctl);
> +
>  int snd_soc_bytes_info(struct snd_kcontrol *kcontrol,
>  		       struct snd_ctl_elem_info *uinfo)
>  {
>