[PATCH 1/1] Added functionality for E-mu 0404USB/0202USB/TrackerPre

[Zerg Cannibal <cnb_zerg@yahoo.com>]

Added functionality:
1) Extension Units support (all XU settings now available at alsamixer, kmix, etc):
 - "AnalogueIn soft limiter" switch;
 - "Sample rate" selector (values 0,1,2,3,4,5 corresponds to 44.1 48 ... 192 kHz);
 - "DigitalIn CLK source" selector (internal/external) (**);
 - "DigitalOut format SPDIF/AC3" switch (**);
(**)E-mu-0404usb only.

2) Automatic device sample rate adjustment depending on substream samplerate for both capture and playback substream. 
  
Patch is based on Mac OS-X driver (http://sourceforge.net/projects/zaudiodrivermac/) and successfully tested by Ubuntu community users for 0404usb and 0202usb.

Signed-off-by: CannibalZerg <cnb_zerg@yahoo.com>
---
 sound/usb/usbaudio.c |   44 ++++++++++++++++++++++++++++++
 sound/usb/usbaudio.h |    2 +
 sound/usb/usbmixer.c |   73 +++++++++++++++++++++++++++++++++++++++++++++++---
 3 files changed, 115 insertions(+), 4 deletions(-)

diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index 31b63ea..d8eb029 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -1271,6 +1271,42 @@ static int init_usb_sample_rate(struct usb_device *dev, int iface,
 }
 
 /*
+ * For E-Mu 0404USB/0202USB/TrackerPre sample rate should be set for device,
+ * not for interface.
+*/
+static void set_format_emu_quirk(struct snd_usb_substream *subs, struct audioformat *fmt)
+{
+	unsigned char emu_samplerate_id = 0;
+
+	/* When capture is active sample rate shouldn't be changed by playback substream*/
+	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK) {
+		if (subs->stream->substream[SNDRV_PCM_STREAM_CAPTURE].interface != -1)
+			return;
+	}
+
+	switch (fmt->rate_min) {
+	case 48000:
+		emu_samplerate_id = 1;
+		break;
+	case 88200:
+		emu_samplerate_id = 2;
+		break;
+	case 96000:
+		emu_samplerate_id = 3;
+		break;
+	case 176400:
+		emu_samplerate_id = 4;
+		break;
+	case 192000:
+		emu_samplerate_id = 5;
+		break;
+	default:
+		emu_samplerate_id = 0;
+	}
+	snd_emuusb_set_samplerate(subs->stream->chip, emu_samplerate_id);
+}
+
+/*
  * find a matching format and set up the interface
  */
 static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
@@ -1383,6 +1419,14 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
 
 	subs->cur_audiofmt = fmt;
 
+	switch (subs->stream->chip->usb_id) {
+	case USB_ID(0x041e, 0x3f02): /* E-Mu 0202 USB */
+	case USB_ID(0x041e, 0x3f04): /* E-Mu 0404 USB */
+	case USB_ID(0x041e, 0x3f0a): /* E-Mu Tracker Pre */
+		set_format_emu_quirk(subs, fmt);
+	break;
+	}
+
 #if 0
 	printk(KERN_DEBUG
 	       "setting done: format = %d, rate = %d..%d, channels = %d\n",
diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
index 9826337..8558773 100644
--- a/sound/usb/usbaudio.h
+++ b/sound/usb/usbaudio.h
@@ -233,6 +233,8 @@ void snd_usbmidi_input_stop(struct list_head* p);
 void snd_usbmidi_input_start(struct list_head* p);
 void snd_usbmidi_disconnect(struct list_head *p);
 
+void snd_emuusb_set_samplerate(struct snd_usb_audio *chip, unsigned char samplerate_id);
+
 /*
  * retrieve usb_interface descriptor from the host interface
  * (conditional for compatibility with the older API)
diff --git a/sound/usb/usbmixer.c b/sound/usb/usbmixer.c
index c998220..400208c 100644
--- a/sound/usb/usbmixer.c
+++ b/sound/usb/usbmixer.c
@@ -186,6 +186,21 @@ enum {
 	USB_PROC_DCR_RELEASE = 6,
 };
 
+/*E-mu 0202(0404) eXtension Unit(XU) control*/
+enum {
+  USB_XU_CLOCK_RATE 		= 0xe301,
+  USB_XU_CLOCK_SOURCE		= 0xe302,
+  USB_XU_DIGITAL_IO_STATUS	= 0xe303,
+  USB_XU_DEVICE_OPTIONS	= 0xe304,
+  USB_XU_DIRECT_MONITORING	= 0xe305,
+  USB_XU_METERING		= 0xe306
+};
+enum {
+	USB_XU_CLOCK_SOURCE_SELECTOR = 0x02,	/* clock source*/
+	USB_XU_CLOCK_RATE_SELECTOR = 0x03,	/* clock rate */
+	USB_XU_DIGITAL_FORMAT_SELECTOR = 0x01,   /* the spdif format */
+	USB_XU_SOFT_LIMIT_SELECTOR = 0x03 /* soft limiter */
+};
 
 /*
  * manual mapping of mixer names
@@ -1330,7 +1345,32 @@ static struct procunit_info procunits[] = {
 	{ USB_PROC_DCR, "DCR", dcr_proc_info },
 	{ 0 },
 };
-
+/*
+ * predefined data for extension units
+ */
+static struct procunit_value_info clock_rate_xu_info[] = {
+       { USB_XU_CLOCK_RATE_SELECTOR, "Selector", USB_MIXER_U8, 0},
+       { 0 }
+};
+static struct procunit_value_info clock_source_xu_info[] = {
+	{ USB_XU_CLOCK_SOURCE_SELECTOR, "External", USB_MIXER_BOOLEAN},
+	{ 0 }
+};
+static struct procunit_value_info spdif_format_xu_info[] = {
+	{ USB_XU_DIGITAL_FORMAT_SELECTOR, "SPDIF/AC3", USB_MIXER_BOOLEAN},
+	{ 0 }
+};
+static struct procunit_value_info soft_limit_xu_info[] = {
+	{ USB_XU_SOFT_LIMIT_SELECTOR, " ", USB_MIXER_BOOLEAN},
+	{ 0 }
+};
+static struct procunit_info extunits[] = {
+	{ USB_XU_CLOCK_RATE, "Clock rate", clock_rate_xu_info },
+	{ USB_XU_CLOCK_SOURCE, "DigitalIn CLK source", clock_source_xu_info },
+	{ USB_XU_DIGITAL_IO_STATUS, "DigitalOut format:", spdif_format_xu_info },
+	{ USB_XU_DEVICE_OPTIONS, "AnalogueIn Soft Limit", soft_limit_xu_info },
+	{ 0 }
+};
 /*
  * build a processing/extension unit
  */
@@ -1391,8 +1431,16 @@ static int build_audio_procunit(struct mixer_build *state, int unitid, unsigned
 			cval->max = dsc[15];
 			cval->res = 1;
 			cval->initialized = 1;
-		} else
-			get_min_max(cval, valinfo->min_value);
+		} else {
+			if (type == USB_XU_CLOCK_RATE) {
+				/*E-Mu USB 0404/0202/TrackerPre samplerate control quirk*/
+						cval->min = 0;
+						cval->max = 5;
+						cval->res = 1;
+						cval->initialized = 1;
+			} else
+				get_min_max(cval, valinfo->min_value);
+		}
 
 		kctl = snd_ctl_new1(&mixer_procunit_ctl, cval);
 		if (! kctl) {
@@ -1433,7 +1481,7 @@ static int parse_audio_processing_unit(struct mixer_build *state, int unitid, un
 
 static int parse_audio_extension_unit(struct mixer_build *state, int unitid, unsigned char *desc)
 {
-	return build_audio_procunit(state, unitid, desc, NULL, "Extension Unit");
+	return build_audio_procunit(state, unitid, desc, extunits, "Extension Unit");
 }
 
 
@@ -2109,6 +2157,23 @@ static int snd_xonar_u1_controls_create(struct usb_mixer_interface *mixer)
 	return 0;
 }
 
+void snd_emuusb_set_samplerate(struct snd_usb_audio *chip, unsigned char samplerate_id)
+{
+	 struct usb_mixer_interface *mixer;
+	 struct list_head *p;
+	 struct usb_mixer_elem_info *cval;
+	 int unitid = 12; /*SampleRate ExtensionUnit ID*/
+	 list_for_each(p, &chip->mixer_list) {
+		 mixer = list_entry(p, struct usb_mixer_interface, list);
+		 cval = mixer->id_elems[unitid];
+		 if (cval) {
+			 set_cur_ctl_value(cval, cval->control << 8, samplerate_id);
+			 snd_usb_mixer_notify_id(mixer, unitid);
+		 }
+		 break;
+	 }
+}
+
 int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
 			 int ignore_error)
 {
-- 
1.6.5.6