[alsa-devel] [PATCH V6 1/2] ASoC: core: add API for registering and cleaning up DMI card names

[Takashi Sakamoto]

Hi,

On Apr 6 2016 13:43, han.lu at intel.com wrote:
> From: "Lu, Han" <han.lu at intel.com>
>
> Add core API for registering and cleaning up DMI card names, so user
> space utils such as PA and UCM can distinguish various products.
> Previously on ASoC, the card short name, driver name and long name are
> all the same as the machine driver name.
> The patch adds more board information:
>    card driver name --->  machine driver name
>    card short name  --->  DMI_BOARD_NAME or DMI_PRODUCT_NAME
>    card long name and
>    card component   --->  short name;driver name;(DMI_SYS_VENDOR,
>                           optional);(the firmware name, optional)
>
> Signed-off-by: Lu, Han <han.lu at intel.com>
>
> diff --git a/include/sound/soc.h b/include/sound/soc.h
> index 02b4a21..911d09e 100644
> --- a/include/sound/soc.h
> +++ b/include/sound/soc.h
> @@ -486,6 +486,9 @@ 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_card_names(struct snd_soc_card *card, const char *firmware);
> +void snd_soc_cleanup_card_names(struct snd_soc_card *card);
> +
>   /* 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);
> diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
> index d2e62b15..0cfffff 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>
> @@ -1828,6 +1829,92 @@ int snd_soc_runtime_set_dai_fmt(struct snd_soc_pcm_runtime *rtd,
>   }
>   EXPORT_SYMBOL_GPL(snd_soc_runtime_set_dai_fmt);
>
> +/**
> + * snd_soc_set_card_names() - Register DMI names to card
> + * @card: The card to register DMI names
> + * @board: DMI_BOARD_NAME or DMI_PRODUCT_NAME
> + * @vendor: DMI_SYS_VENDOR, optional
> + * @firmware: The firmware name, optional
> + *
> + * This function registers DMI names to card for the userspace to distinguish
> + * different boards/products:
> + *   card driver name --->  machine driver name
> + *   card short name  --->  DMI_BOARD_NAME or DMI_PRODUCT_NAME
> + *   card long name and
> + *   card component   --->  short name;driver name;(DMI_SYS_VENDOR, optional)
> + *                          ;(firmware name, optional)
> + *
> + * Returns 0 on success, otherwise a negative error code.
> + */
> +int snd_soc_set_card_names(struct snd_soc_card *card, const char *firmware)
> +{
> +	int ret = 0;
> +	size_t buf_size, name_size;
> +	const char *board, *vendor;
> +	char *longname;
> +
> +	board = dmi_get_system_info(DMI_BOARD_NAME);
> +	if (!board)
> +		board = dmi_get_system_info(DMI_PRODUCT_NAME);
> +	if (!board) {
> +		dev_err(card->dev, "ASoC: the board/product name is empty!\n");
> +		return -EINVAL;
> +	}
> +
> +	vendor = dmi_get_system_info(DMI_SYS_VENDOR);
> +
> +	/* card driver name */
> +	card->driver_name = card->name;
> +
> +	/* card short name */
> +	card->name = board;
> +
> +	/* card long name */
> +	buf_size = sizeof(card->snd_card->longname);
> +	name_size = strlen(card->name) + strlen(card->driver_name) + 4;
> +	if (vendor)
> +		name_size += strlen(vendor);
> +	if (firmware)
> +		name_size += strlen(firmware);
> +	if (name_size > buf_size)
> +		return -ENOMEM;
> +
> +	longname = kmalloc(buf_size, GFP_KERNEL);
> +	if (!longname)
> +		return -ENOMEM;
> +	snprintf(longname, buf_size, "%s;%s;",
> +			card->name, card->driver_name);
> +	if (vendor)
> +		strlcat(longname, vendor, buf_size);
> +	strlcat(longname, ";", buf_size);
> +	if (firmware)
> +		strlcat(longname, firmware, buf_size);
> +
> +	card->long_name = longname;
> +
> +	/* card component */
> +	if (sizeof(card->snd_card->components) < name_size
> +			+ strlen(card->snd_card->components))
> +		return -ENOMEM;
> +
> +	ret = snd_component_add(card->snd_card, card->long_name);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(snd_soc_set_card_names);
> +
> +/**
> + * snd_soc_cleanup_card_names() - cleanup registered DMI names
> + * @card: The card to cleanup
> + *
> + * This function cleanup the registered DMI names from card
> + */
> +void snd_soc_cleanup_card_names(struct snd_soc_card *card)
> +{
> +	kfree(card->long_name);
> +}
> +EXPORT_SYMBOL_GPL(snd_soc_cleanup_card_names);
> +

Hm. How about do it in a path to release devres? In short,

When registering card instance, devm_card_release is assigned to the 
resource.
devm_snd_soc_register_card()
->devres_alloc(devm_card_release, sizeof(*ptr), GFP_KERNEL);

When releasing the resource:
(sound/soc/soc-devres.c)
->devm_card_release()
   (sound/soc/soc-core.c)
   ->snd_soc_unregister_card()
     ->kfree(card->long_name) (yours)

I just have a quick glance. It's better for you to confirm it in your case.


Regards

Takashi Sakamoto

>   static int snd_soc_instantiate_card(struct snd_soc_card *card)
>   {
>   	struct snd_soc_codec *codec;