From 3a572d94bcff98a14c94fe686881a169a26f3fca Mon Sep 17 00:00:00 2001 From: Jussi Laako Date: Wed, 13 Jun 2018 01:43:01 +0300 Subject: 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: Jussi Laako Signed-off-by: Takashi Iwai --- sound/usb/card.h | 1 + sound/usb/format.c | 5 ++++- sound/usb/quirks.c | 13 +++++++++++++ 3 files changed, 18 insertions(+), 1 deletion(-) (limited to 'sound/usb') diff --git a/sound/usb/card.h b/sound/usb/card.h index 1406292d50ec..9b41b7dda84f 100644 --- a/sound/usb/card.h +++ b/sound/usb/card.h @@ -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; diff --git a/sound/usb/format.c b/sound/usb/format.c index 49e7ec6d2399..0a2a27f2854d 100644 --- a/sound/usb/format.c +++ b/sound/usb/format.c @@ -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; diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c index f4b69173682c..c616c251dbac 100644 --- a/sound/usb/quirks.c +++ b/sound/usb/quirks.c @@ -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; } -- cgit