Commit 3a572d94 authored by Jussi Laako's avatar Jussi Laako Committed by Takashi Iwai
Browse files

ALSA: usb-audio: Add native DSD support for Mytek DACs 



Add new mostly generic code with Mytek VID to support native DSD mode.

This implementation should be easier to maintain when manufacturers
release new products.

Signed-off-by: default avatarJussi Laako <jussi@sonarnerd.net>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent c7273bd6

sound/usb/card.h

+1 −0
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ struct audioformat { 
	struct snd_pcm_chmap_elem *chmap; /* (optional) channel map */

	bool dsd_dop;			/* add DOP headers in case of DSD samples */

	bool dsd_bitrev;		/* reverse the bits of each DSD sample */

	bool dsd_raw;			/* altsetting is raw DSD */

};



struct snd_usb_substream;

sound/usb/format.c

+4 −1
Original line number Diff line number Diff line
@@ -64,8 +64,11 @@ static u64 parse_audio_format_i_type(struct snd_usb_audio *chip, 
		sample_width = fmt->bBitResolution;

		sample_bytes = fmt->bSubslotSize;



		if (format & UAC2_FORMAT_TYPE_I_RAW_DATA)

		if (format & UAC2_FORMAT_TYPE_I_RAW_DATA) {

			pcm_formats |= SNDRV_PCM_FMTBIT_SPECIAL;

			/* flag potentially raw DSD capable altsettings */

			fp->dsd_raw = true;

		}



		format <<= 1;

		break;

sound/usb/quirks.c

+13 −0
Original line number Diff line number Diff line
@@ -1443,6 +1443,19 @@ u64 snd_usb_interface_dsd_format_quirks(struct snd_usb_audio *chip, 
			return SNDRV_PCM_FMTBIT_DSD_U32_BE;

	}



	/* Mostly generic method to detect many DSD-capable implementations -

	 * from XMOS/Thesycon

	 */

	switch (USB_ID_VENDOR(chip->usb_id)) {

	case 0x25ce:  /* Mytek devices */

		if (fp->dsd_raw)

			return SNDRV_PCM_FMTBIT_DSD_U32_BE;

		break;

	default:

		break;



	}



	return 0;

}