Re: [PATCH v2 1/2] ASoC: core: Add API to use DMI name in sound card long name

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

On Tue, 2017-01-03 at 15:44 +0000, Lin, Mengdong wrote:
> > -----Original Message-----
> > From: Liam Girdwood [mailto:liam.r.girdwood@linux.intel.com]
> > Sent: Tuesday, January 3, 2017 10:40 PM
> > To: mengdong.lin@linux.intel.com
> > Cc: alsa-devel@alsa-project.org; broonie@kernel.org; tiwai@suse.de; Lin,
> > Mengdong <mengdong.lin@intel.com>; Koul, Vinod <vinod.koul@intel.com>;
> > Bossart, Pierre-louis <pierre-louis.bossart@intel.com>
> > Subject: Re: [alsa-devel] [PATCH v2 1/2] ASoC: core: Add API to use DMI name
> > in sound card long name
> > 
> > On Tue, 2017-01-03 at 12:58 +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 use the DMI
> > > info like vendor, product and board to make up the card long name. If
> > > the machine driver has already explicitly set the long name, 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.
> > >
> > > For Use Case Manager (UCM) in the user space, changing card long name
> > > by this API is backward compatible, since the card name does not
> > > change. For a given sound card, even if there is no device-specific
> > > UCM configuration file that uses the card long name, UCM will fall
> > > back to load the default configuration file that uses the card name.
> > >
> > > 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..e4f1844 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 +1096,8 @@ struct snd_soc_card {
> > >  	const char *name;
> > >  	const char *long_name;
> > >  	const char *driver_name;
> > > +	char dmi_longname[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..3dbb5aa 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 +1887,104 @@ int snd_soc_runtime_set_dai_fmt(struct
> > > snd_soc_pcm_runtime *rtd,  }
> > > EXPORT_SYMBOL_GPL(snd_soc_runtime_set_dai_fmt);
> > >
> > > +
> > > +/* Only keep number and alphabet characters and a few separator
> > characters.
> > > + * DMI info often has SPACE and we must trim them, since Use Case
> > > +Manager in
> > > + * the user space expects the device-specific configuration
> > > +files/directories
> > > + * use the same name as the card long name but Autoconf cannot
> > > +support SPACE
> > > + * in file or directory name.
> > > + */
> > > +static void trim_special_characters(char *name) {
> > > +	int i, j = 0;
> > > +
> > > +	for (i = 0; name[i]; i++) {
> > > +		if (isalnum(name[i]) || (name[i] == '.')
> > > +		    || (name[i] == '-') || (name[i] == '_'))
> > > +			name[j++] = name[i];
> > > +	}
> > > +
> > > +	name[j] = '\0';
> > > +}
> > > +
> > > +/**
> > > + * 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 as the
> > > +sound
> > > + * card long name, thereby helping userspace load the correct UCM
> > > +(Use Case
> > > + * Manager) configuration. Character '.' are used to separate
> > > +different DMI
> > > + * fields like "vendor.product.board".
> > > + *
> > > + * Possible card long names may be:
> > > + * DellInc..XPS139343.0310JH
> > > + * IntelCorp..BroadwellClientPlatform.WilsonBeachSDS
> > > + * ASUSTeKCOMPUTERINC..T100TA.T100TA
> > > + * Circuitco.MinnowboardMaxD0PLATFORM.MinnowBoardMAX
> > > + * (Please note DMI info can also include '.' after some abbreviation
> > > +like
> > > + * "Inc." so you may see double '.' sometimes)
> > > + *
> > > + * This function also supports flavoring the card longname to provide
> > > + * the extra differentiation, like "vendor.product.board.flavor".
> > 
> > I dont think we need vendor (it just makes it too long). The product or board
> > name should be unique enough for us to load the correct files.
> > 
> > Liam
> 
> Yes, from the sample machines I checked, product or board name are
> unique. But I feel there might be the risk that two vendors happen to
> use the same product or board name, e.g. "T100TA".

I think this would be problematic from a legal/marketing position from
two different vendors so it would be unlikely.

Liam

> 
> And if we want to add the vendor field later, we may need to rename
> existing UCM configuration files and directories, which may be not so
> easy if those machines are not around us.
> 
> Thanks
> Mengdong
> 
> > 
> > > + *
> > > + * We only keep number and alphabet characters and a few separator
> > > +characters
> > > + * in the card long name since UCM in the user space uses the card
> > > +long names
> > > + * as card configuration directory names and AudoConf cannot support
> > > +special
> > > + * charactors like SPACE.
> > > + *
> > > + * 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;
> > > +	char dmi_longname[80];
> > > +
> > > +	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: vendor.product.board */
> > > +	if (product && board)
> > > +		snprintf(dmi_longname, sizeof(card->snd_card->longname),
> > > +			 "%s.%s.%s", vendor, product, board);
> > > +	else
> > > +		snprintf(dmi_longname, sizeof(card->snd_card->longname),
> > > +			 "%s.%s", vendor, product ? product : board);
> > > +
> > > +	/* Add flavour to dmi long name */
> > > +	if (flavour)
> > > +		snprintf(card->dmi_longname, sizeof(card->snd_card-
> > >longname),
> > > +			 "%s.%s", dmi_longname, flavour);
> > > +	else
> > > +		strncpy(card->dmi_longname, dmi_longname,
> > > +			sizeof(card->snd_card->longname) - 1);
> > > +
> > > +	trim_special_characters(card->dmi_longname);
> > > +
> > > +	/* 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;
> > 
> 
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