ALSA: usb-audio: Add mode select quirk for Denon/Marantz DACs

Denon/Marantz USB DACs need a specific vendor command to switch between PCM and
DSD mode. This patch adds a new quirk function to switch between the two modes
using the specific USB vendor command.

This patch applies to the following devices:
- Marantz SA-14S1
- Marantz HD-DAC1

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

1 files changed, 38 insertions, 0 deletions

diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index a9d4add..e0cde74 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -1111,6 +1111,44 @@ void snd_usb_set_format_quirk(struct snd_usb_substream *subs,
 	}
 }
 
+
+/* Marantz/Denon USB DACs need a vendor cmd to switch
+ * between PCM and native DSD mode
+ */
+int snd_usb_select_mode_quirk(struct snd_usb_substream *subs,
+			      struct audioformat *fmt)
+{
+	struct usb_device *dev = subs->dev;
+	int err;
+
+	switch (subs->stream->chip->usb_id) {
+	case USB_ID(0x154e, 0x3005): /* Marantz HD-DAC1 */
+	case USB_ID(0x154e, 0x3006): /* Marantz SA-14S1 */
+
+		/* First switch to alt set 0, otherwise the mode switch cmd
+		 * will not be accepted by the DAC
+		 */
+		err = usb_set_interface(dev, fmt->iface, 0);
+		if (err < 0)
+			return err;
+
+		mdelay(20); /* Delay needed after setting the interface */
+
+		switch (fmt->altsetting) {
+		case 2: /* DSD mode requested */
+		case 1: /* PCM mode requested */
+			err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), 0,
+					      USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
+					      fmt->altsetting - 1, 1, NULL, 0);
+			if (err < 0)
+				return err;
+			break;
+		}
+		mdelay(20);
+	}
+	return 0;
+}
+
 void snd_usb_endpoint_start_quirk(struct snd_usb_endpoint *ep)
 {
 	/*