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

[Liam Girdwood <liam.r.girdwood@linux.intel.com>]

On Fri, 2016-12-16 at 10:51 +0800, mengdong.lin@linux.intel.com wrote:
> From: Liam Girdwood <liam.r.girdwood@linux.intel.com>
> 
> Intel DSP platform drivers are used by many different devices but are
> difficult for userspace to differentiate. This patch adds an API to allow
> the DMI name to be used in the sound card long name, thereby helping
> userspace load the correct UCM configuration. Usually machine drivers
> uses their own name as the sound card name (short name), and leave the
> long name and driver name blank. This API will generate DMI name from the
> DMI vendor, product and board info, and then make up a unique card long
> name from the short name and DMI name. If the machine driver has already
> explicitly set the long name, although not observed, this API will do
> nothing.
> 
> This patch also allows for further differentiation as many devices that
> share the same DMI name i.e. Minnowboards, UP boards may be configured
> with different codecs or firmwares. The API supports flavoring the DMI
> name into the card longname to provide the extra differentiation required
> for these devices.
> 
> Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
> Signed-off-by: Mengdong Lin <mengdong.lin@linux.intel.com>
> 
> diff --git a/include/sound/soc.h b/include/sound/soc.h
> index 795e6c4..b84648f 100644
> --- a/include/sound/soc.h
> +++ b/include/sound/soc.h
> @@ -497,6 +497,8 @@ void snd_soc_runtime_deactivate(struct snd_soc_pcm_runtime *rtd, int stream);
>  int snd_soc_runtime_set_dai_fmt(struct snd_soc_pcm_runtime *rtd,
>  	unsigned int dai_fmt);
>  
> +int snd_soc_set_dmi_name(struct snd_soc_card *card, const char *flavour);
> +
>  /* 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 +1096,9 @@ struct snd_soc_card {
>  	const char *name;
>  	const char *long_name;
>  	const char *driver_name;
> +	char dmi_longname[80];
> +	char board_name[80];
> +
>  	struct device *dev;
>  	struct snd_card *snd_card;
>  	struct module *owner;
> diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
> index aaab26a..bb6a23a 100644
> --- a/sound/soc/soc-core.c
> +++ b/sound/soc/soc-core.c
> @@ -34,6 +34,7 @@
>  #include <linux/ctype.h>
>  #include <linux/slab.h>
>  #include <linux/of.h>
> +#include <linux/dmi.h>
>  #include <sound/core.h>
>  #include <sound/jack.h>
>  #include <sound/pcm.h>
> @@ -1886,6 +1887,139 @@ int snd_soc_runtime_set_dai_fmt(struct snd_soc_pcm_runtime *rtd,
>  }
>  EXPORT_SYMBOL_GPL(snd_soc_runtime_set_dai_fmt);
>  
> +/* Move the DMI stuff below to a new file soc-dmi.c? */
> +struct snd_soc_dmi_name  {
> +	const char *vendor;
> +	const char *product;
> +	const char *board;
> +	const char *name;
> +};
> +
> +#define SOC_DMI_ENTRY(_vendor, _product, _board, _name) \
> +	{ .vendor = (_vendor), .board = (_board), \
> +	  .product = (_product), .name = (_name) }
> +
> +/* DMI names. The matched DMI name will be appended to the card short name
> + * to make up the card long name. Machine drivers ususally use their own name
> + * as the card short name, and leave the long name empty. Machine driver may
> + * call API snd_soc_set_dmi_name() to get a unique long name. In user space,
> + * Use Case Manager (UCM) will try to find the best configuration file by
> + * matching the card long name at first, and if unavailable, match the short
> + * name as a fallback.
> + * For example, for a Boradwell-based Dell XPS 13-2015(9343), the card short
> + * name is "broadwell-rt286" and the DMI name is "DELL-XPS", so the long name
> + * will be "broadwell-rt286-Dell-XPS". For a new Skylake-based Dell XPS 13/15,
> + * if the short name is "skl-xyz" and DMI name is "Dell-XPS", the long name
> + * will be "skl-xyz-Dell-XPS".In user space, Use Case Manager (UCM) will try
> + * to find the best configuration file by matching the card long name (e.g.
> + * broadwell-rt286-Dell-XPS), and if unavailable, fallback to the default
> + * configuration file by matching the short name (e.g. broadwell-rt286).
> + */
> +static struct snd_soc_dmi_name dmi_names[]  = {
> +	SOC_DMI_ENTRY("Intel Corp.", "Broadwell Client platform",
> +		      "Wilson Beach SDS", "Intel-Wilson-Beach"),
> +	SOC_DMI_ENTRY("Dell Inc.", "XPS 13 9343", "0310JH", "Dell-XPS"),
> +	SOC_DMI_ENTRY("ASUSTeK COMPUTER INC.", "T100TA", "T100TA",
> +		      "ASUS-T100"),
> +	{}	/* terminator */
> +};


We cant have any tables here or add new data for each machine. The
intention is that the long name should be made from the DMI name (just a
verbatim copy really). That way we dont need to do any new driver
updates for a new machine, we just read the DMI name.

UCM will then try and find a config for the long name first, then will
revert to the current short/driver name to load the existing configs.
This way we dont break legacy or current users.

Liam

> +
> +/* retrieve the last word of shortname or longname */
> +static const char *retrieve_id_from_card_name(const char *name)
> +{
> +	const char *spos = name;
> +
> +	while (*name) {
> +		if (isspace(*name) && isalnum(name[1]))
> +			spos = name + 1;
> +		name++;
> +	}
> +	return spos;
> +}
> +
> +static const char *find_dmi_name(const char *vendor, const char *product,
> +			const char *board)
> +{
> +	struct snd_soc_dmi_name *name_entry;
> +
> +	/* vendor must be valid, either product or board must to be valid */
> +	if (!vendor || (!product && !board))
> +		return NULL;
> +
> +	name_entry = dmi_names;
> +	while (name_entry->vendor) {
> +		if (!strncmp(vendor, name_entry->vendor, 32)
> +		    && (!product
> +			|| !strncmp(product, name_entry->product, 32))
> +		    && (!board || !strncmp(board, name_entry->board, 32)))
> +			return name_entry->name;
> +
> +		name_entry++;
> +	}
> +
> +	return NULL;
> +}
> +
> +/**
> + * 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.
> + *
> + * 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, *name;
> +	char *spos;
> +
> +	if (card->long_name)
> +		return 0; /* already set long name by driver or from DMI */
> +
> +	vendor = dmi_get_system_info(DMI_BOARD_VENDOR);
> +	if (!vendor) {
> +		dev_warn(card->dev, "ASoC: the DMI vendor name is empty!\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: both board/product name are empty!\n");
> +		return 0;
> +	}
> +
> +	name = find_dmi_name(vendor, product, board);
> +	if (name)
> +		snprintf(card->board_name, sizeof(card->board_name),
> +			"%s-%s", card->name, name);
> +	else
> +		snprintf(card->board_name, sizeof(card->snd_card->longname),
> +			"%s-%s-%s-%s", card->name, vendor, product, board);
> +
> +	/* replace SPACE with '-' */
> +	spos = card->board_name;
> +	while (*spos) {
> +		if (isspace(*spos))
> +			*spos = '-';
> +		spos++;
> +	}
> +
> +	/* long name */
> +	card->long_name = card->board_name;
> +
> +	/* Add flavour to long name */
> +	if (flavour) {
> +		snprintf(card->dmi_longname, sizeof(card->snd_card->longname),
> +			"%s-%s", retrieve_id_from_card_name(card->long_name),
> +			flavour);
> +		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;