Re: [PATCH 1/2] ASoC: core: Add API to use DMI name in sound card long name

[Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>]

>  /* Utility functions to get clock rates from various things */
>  int snd_soc_calc_frame_size(int sample_size, int channels, int tdm_slots);
>  int snd_soc_params_to_frame_size(struct snd_pcm_hw_params *params);
> @@ -1094,6 +1096,8 @@ struct snd_soc_card {
>  	const char *name;
>  	const char *long_name;
>  	const char *driver_name;
> +	char dmi_longname[80];

why 80? is this linked to DMI restrictions on board/product names?

>
> +/**
> + * snd_soc_set_dmi_name() - Register DMI names to card
> + * @card: The card to register DMI names
> + * @flavour: The flavour "differentiator" for the card amongst its peers.
> + *
> + * Intel DSP platform drivers are used by many different devices but are
> + * difficult for userspace to differentiate, since machine drivers ususally
> + * use their own name as the card name (short name) and leave the card long
> + * name blank. This function will allow DMI info to be used in the sound
> + * card long name, thereby helping userspace load the correct UCM (Use Case
> + * Manager) configuration.
> + * Possible card long names may be:
> + * broadwell-rt286-Dell Inc.-XPS 13 9343-0310JH
> + * broadwell-rt286-Intel Corp.-Broadwell Client platform-Wilson Beach SDS
> + * bytcr-rt5640-ASUSTeK COMPUTER INC.-T100TA-T100TA
> + * bytcr-rt5651-Circuitco-Minnowboard Max D0 PLATFORM-MinnowBoard MAX

You may want to add a comment that the '.' is not a separator but part 
of the DMI name. I was trying to figure out why there were cases with .-

> + *
> + * This function also supports flavoring the card longname to provide
> + * the extra differentiation.
> + *
> + * Returns 0 on success, otherwise a negative error code.
> + */
> +int snd_soc_set_dmi_name(struct snd_soc_card *card, const char *flavour)
> +{
> +	const char *vendor, *product, *board;
> +
> +	if (card->long_name)
> +		return 0; /* long name already set by driver or from DMI */
> +
> +	vendor = dmi_get_system_info(DMI_BOARD_VENDOR);
> +	if (!vendor) {
> +		dev_warn(card->dev, "ASoC: no DMI vendor name!\n");
> +		return 0;
> +	}
> +
> +	product = dmi_get_system_info(DMI_PRODUCT_NAME);
> +	board = dmi_get_system_info(DMI_BOARD_NAME);
> +	if (!board && !product) {
> +		/* fall back to using legacy name */
> +		dev_warn(card->dev, "ASoC: no DMI board/product name!\n");
> +		return 0;
> +	}
> +
> +	/* make up dmi long name as:
> +	 * card name (usually machine driver name) -vendor -product -board
> +	 */
> +	snprintf(card->dmi_longname, sizeof(card->snd_card->longname),
> +			"%s-%s", card->name, vendor);
> +
> +	if (product) {
> +		strncat(card->dmi_longname, "-",
> +			sizeof(card->snd_card->longname));
> +		strncat(card->dmi_longname, product,
> +			sizeof(card->snd_card->longname));
> +	}
> +
> +	if (board) {
> +		strncat(card->dmi_longname, "-",
> +			sizeof(card->snd_card->longname));
> +		strncat(card->dmi_longname, board,
> +			sizeof(card->snd_card->longname));
> +	}
> +
> +
> +	/* Add flavour to dmi long name */
> +	if (flavour) {
> +		strncat(card->dmi_longname, "-",
> +			sizeof(card->snd_card->longname));
> +		strncat(card->dmi_longname, flavour,
> +			sizeof(card->snd_card->longname));
> +	}

how is the 'flavour' defined? This doesn't seem to come from the DMI 
decode information? Is this for example intended to be used with quirks?


> +
> +	/* set long name */
> +	card->long_name = card->dmi_longname;
> +
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(snd_soc_set_dmi_name);
> +
>  static int snd_soc_instantiate_card(struct snd_soc_card *card)
>  {
>  	struct snd_soc_codec *codec;
>