ALSA: usb-audio: add native DSD support for XMOS based DACs

Add quirks for XMOS based DACs for native DSD playback support using the new
DSD_U32_LE sample format.

This version adds native DSD support for:
- iFi Audio micro iDSD/nano iDSD (they use the same prod. id)
- DIYINHK USB to I2S/DSD converter

Changes from v2:
- fix and simplify switch statement
Changes from v1:
- use specific product id and alt setting per XMOS based device

[fixed a misc coding style issue by tiwai]

Signed-off-by: Jurgen Kramer <gtmkramer@xs4all.nl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 16 insertions, 0 deletions

diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 19a921eb75f1..d2aa45a8d895 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -1174,5 +1174,21 @@ u64 snd_usb_interface_dsd_format_quirks(struct snd_usb_audio *chip,
                 }
         }
 
+        /* XMOS based USB DACs */
+        switch (chip->usb_id) {
+        /* iFi Audio micro/nano iDSD */
+        case USB_ID(0x20b1, 0x3008):
+                if (fp->altsetting == 2)
+                        return SNDRV_PCM_FMTBIT_DSD_U32_LE;
+                break;
+        /* DIYINHK DSD DXD 384kHz USB to I2S/DSD */
+        case USB_ID(0x20b1, 0x2009):
+                if (fp->altsetting == 3)
+                        return SNDRV_PCM_FMTBIT_DSD_U32_LE;
+                break;
+        default:
+                break;
+        }
+
         return 0;
 }