Merge branch 'fix/misc' into topic/misc

13 files changed, 634 insertions, 247 deletions

diff --git a/sound/usb/Makefile b/sound/usb/Makefile
index e7ac7f4..1e362bf 100644
--- a/sound/usb/Makefile
+++ b/sound/usb/Makefile
@@ -11,7 +11,8 @@ snd-usb-audio-objs := 	card.o \
 			endpoint.o \
 			urb.o \
 			pcm.o \
-			helper.o
+			helper.o \
+			clock.o
 
 snd-usbmidi-lib-objs := midi.o
 
diff --git a/sound/usb/card.c b/sound/usb/card.c
index da1346b..7a8ac1d 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -236,7 +236,6 @@ static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
 	}
 
 	case UAC_VERSION_2: {
-		struct uac_clock_source_descriptor *cs;
 		struct usb_interface_assoc_descriptor *assoc =
 			usb_ifnum_to_if(dev, ctrlif)->intf_assoc;
 
@@ -245,21 +244,6 @@ static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
 			return -EINVAL;
 		}
 
-		/* FIXME: for now, we expect there is at least one clock source
-		 * descriptor and we always take the first one.
-		 * We should properly support devices with multiple clock sources,
-		 * clock selectors and sample rate conversion units. */
-
-		cs = snd_usb_find_csint_desc(host_iface->extra, host_iface->extralen,
-						NULL, UAC2_CLOCK_SOURCE);
-
-		if (!cs) {
-			snd_printk(KERN_ERR "CLOCK_SOURCE descriptor not found\n");
-			return -EINVAL;
-		}
-
-		chip->clock_id = cs->bClockID;
-
 		for (i = 0; i < assoc->bInterfaceCount; i++) {
 			int intf = assoc->bFirstInterface + i;
 
@@ -481,6 +465,8 @@ static void *snd_usb_audio_probe(struct usb_device *dev,
 			goto __error;
 	}
 
+	chip->ctrl_intf = alts;
+
 	if (err > 0) {
 		/* create normal USB audio interfaces */
 		if (snd_usb_create_streams(chip, ifnum) < 0 ||
diff --git a/sound/usb/card.h b/sound/usb/card.h
index ed92420..1febf2f 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -25,6 +25,7 @@ struct audioformat {
 	unsigned int rate_min, rate_max;	/* min/max rates */
 	unsigned int nr_rates;		/* number of rate table entries */
 	unsigned int *rate_table;	/* rate table */
+	unsigned char clock;		/* associated clock */
 };
 
 struct snd_usb_substream;
diff --git a/sound/usb/clock.c b/sound/usb/clock.c
new file mode 100644
index 0000000..b585511
--- /dev/null
+++ b/sound/usb/clock.c
@@ -0,0 +1,315 @@
+/*
+ *   Clock domain and sample rate management functions
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/bitops.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/usb.h>
+#include <linux/moduleparam.h>
+#include <linux/mutex.h>
+#include <linux/usb/audio.h>
+#include <linux/usb/audio-v2.h>
+
+#include <sound/core.h>
+#include <sound/info.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/initval.h>
+
+#include "usbaudio.h"
+#include "card.h"
+#include "midi.h"
+#include "mixer.h"
+#include "proc.h"
+#include "quirks.h"
+#include "endpoint.h"
+#include "helper.h"
+#include "debug.h"
+#include "pcm.h"
+#include "urb.h"
+#include "format.h"
+
+static struct uac_clock_source_descriptor *
+	snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface,
+				  int clock_id)
+{
+	struct uac_clock_source_descriptor *cs = NULL;
+
+	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
+					     ctrl_iface->extralen,
+					     cs, UAC2_CLOCK_SOURCE))) {
+		if (cs->bClockID == clock_id)
+			return cs;
+	}
+
+	return NULL;
+}
+
+static struct uac_clock_selector_descriptor *
+	snd_usb_find_clock_selector(struct usb_host_interface *ctrl_iface,
+				    int clock_id)
+{
+	struct uac_clock_selector_descriptor *cs = NULL;
+
+	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
+					     ctrl_iface->extralen,
+					     cs, UAC2_CLOCK_SELECTOR))) {
+		if (cs->bClockID == clock_id)
+			return cs;
+	}
+
+	return NULL;
+}
+
+static struct uac_clock_multiplier_descriptor *
+	snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface,
+				      int clock_id)
+{
+	struct uac_clock_multiplier_descriptor *cs = NULL;
+
+	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
+					     ctrl_iface->extralen,
+					     cs, UAC2_CLOCK_MULTIPLIER))) {
+		if (cs->bClockID == clock_id)
+			return cs;
+	}
+
+	return NULL;
+}
+
+static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
+{
+	unsigned char buf;
+	int ret;
+
+	ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
+			      UAC2_CS_CUR,
+			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
+			      UAC2_CX_CLOCK_SELECTOR << 8,
+			      snd_usb_ctrl_intf(chip) | (selector_id << 8),
+			      &buf, sizeof(buf), 1000);
+
+	if (ret < 0)
+		return ret;
+
+	return buf;
+}
+
+static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id)
+{
+	int err;
+	unsigned char data;
+	struct usb_device *dev = chip->dev;
+
+	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
+			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
+			      UAC2_CS_CONTROL_CLOCK_VALID << 8,
+			      snd_usb_ctrl_intf(chip) | (source_id << 8),
+			      &data, sizeof(data), 1000);
+
+	if (err < 0) {
+		snd_printk(KERN_WARNING "%s(): cannot get clock validity for id %d\n",
+			   __func__, source_id);
+		return err;
+	}
+
+	return !!data;
+}
+
+/* Try to find the clock source ID of a given clock entity */
+
+static int __uac_clock_find_source(struct snd_usb_audio *chip,
+				   struct usb_host_interface *host_iface,
+				   int entity_id, unsigned long *visited)
+{
+	struct uac_clock_source_descriptor *source;
+	struct uac_clock_selector_descriptor *selector;
+	struct uac_clock_multiplier_descriptor *multiplier;
+
+	entity_id &= 0xff;
+
+	if (test_and_set_bit(entity_id, visited)) {
+		snd_printk(KERN_WARNING
+			"%s(): recursive clock topology detected, id %d.\n",
+			__func__, entity_id);
+		return -EINVAL;
+	}
+
+	/* first, see if the ID we're looking for is a clock source already */
+	source = snd_usb_find_clock_source(host_iface, entity_id);
+	if (source)
+		return source->bClockID;
+
+	selector = snd_usb_find_clock_selector(host_iface, entity_id);
+	if (selector) {
+		int ret;
+
+		/* the entity ID we are looking for is a selector.
+		 * find out what it currently selects */
+		ret = uac_clock_selector_get_val(chip, selector->bClockID);
+		if (ret < 0)
+			return ret;
+
+		if (ret > selector->bNrInPins || ret < 1) {
+			printk(KERN_ERR
+				"%s(): selector reported illegal value, id %d, ret %d\n",
+				__func__, selector->bClockID, ret);
+
+			return -EINVAL;
+		}
+
+		return __uac_clock_find_source(chip, host_iface,
+					       selector->baCSourceID[ret-1],
+					       visited);
+	}
+
+	/* FIXME: multipliers only act as pass-thru element for now */
+	multiplier = snd_usb_find_clock_multiplier(host_iface, entity_id);
+	if (multiplier)
+		return __uac_clock_find_source(chip, host_iface,
+					       multiplier->bCSourceID, visited);
+
+	return -EINVAL;
+}
+
+int snd_usb_clock_find_source(struct snd_usb_audio *chip,
+			      struct usb_host_interface *host_iface,
+			      int entity_id)
+{
+	DECLARE_BITMAP(visited, 256);
+	memset(visited, 0, sizeof(visited));
+	return __uac_clock_find_source(chip, host_iface, entity_id, visited);
+}
+
+static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
+			      struct usb_host_interface *alts,
+			      struct audioformat *fmt, int rate)
+{
+	struct usb_device *dev = chip->dev;
+	unsigned int ep;
+	unsigned char data[3];
+	int err, crate;
+
+	ep = get_endpoint(alts, 0)->bEndpointAddress;
+
+	/* if endpoint doesn't have sampling rate control, bail out */
+	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE)) {
+		snd_printk(KERN_WARNING "%d:%d:%d: endpoint lacks sample rate attribute bit, cannot set.\n",
+				   dev->devnum, iface, fmt->altsetting);
+		return 0;
+	}
+
+	data[0] = rate;
+	data[1] = rate >> 8;
+	data[2] = rate >> 16;
+	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
+				   USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
+				   UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
+				   data, sizeof(data), 1000)) < 0) {
+		snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n",
+			   dev->devnum, iface, fmt->altsetting, rate, ep);
+		return err;
+	}
+
+	if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
+				   USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
+				   UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
+				   data, sizeof(data), 1000)) < 0) {
+		snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n",
+			   dev->devnum, iface, fmt->altsetting, ep);
+		return 0; /* some devices don't support reading */
+	}
+
+	crate = data[0] | (data[1] << 8) | (data[2] << 16);
+	if (crate != rate) {
+		snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
+		// runtime->rate = crate;
+	}
+
+	return 0;
+}
+
+static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
+			      struct usb_host_interface *alts,
+			      struct audioformat *fmt, int rate)
+{
+	struct usb_device *dev = chip->dev;
+	unsigned char data[4];
+	int err, crate;
+	int clock = snd_usb_clock_find_source(chip, chip->ctrl_intf, fmt->clock);
+
+	if (clock < 0)
+		return clock;
+
+	if (!uac_clock_source_is_valid(chip, clock)) {
+		snd_printk(KERN_ERR "%d:%d:%d: clock source %d is not valid, cannot use\n",
+			   dev->devnum, iface, fmt->altsetting, clock);
+		return -ENXIO;
+	}
+
+	data[0] = rate;
+	data[1] = rate >> 8;
+	data[2] = rate >> 16;
+	data[3] = rate >> 24;
+	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
+				   USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
+				   UAC2_CS_CONTROL_SAM_FREQ << 8,
+				   snd_usb_ctrl_intf(chip) | (clock << 8),
+				   data, sizeof(data), 1000)) < 0) {
+		snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2)\n",
+			   dev->devnum, iface, fmt->altsetting, rate);
+		return err;
+	}
+
+	if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
+				   USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
+				   UAC2_CS_CONTROL_SAM_FREQ << 8,
+				   snd_usb_ctrl_intf(chip) | (clock << 8),
+				   data, sizeof(data), 1000)) < 0) {
+		snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2)\n",
+			   dev->devnum, iface, fmt->altsetting);
+		return err;
+	}
+
+	crate = data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
+	if (crate != rate)
+		snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
+
+	return 0;
+}
+
+int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
+			     struct usb_host_interface *alts,
+			     struct audioformat *fmt, int rate)
+{
+	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
+
+	switch (altsd->bInterfaceProtocol) {
+	case UAC_VERSION_1:
+		return set_sample_rate_v1(chip, iface, alts, fmt, rate);
+
+	case UAC_VERSION_2:
+		return set_sample_rate_v2(chip, iface, alts, fmt, rate);
+	}
+
+	return -EINVAL;
+}
+
diff --git a/sound/usb/clock.h b/sound/usb/clock.h
new file mode 100644
index 0000000..beb2536
--- /dev/null
+++ b/sound/usb/clock.h
@@ -0,0 +1,12 @@
+#ifndef __USBAUDIO_CLOCK_H
+#define __USBAUDIO_CLOCK_H
+
+int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
+			     struct usb_host_interface *alts,
+			     struct audioformat *fmt, int rate);
+
+int snd_usb_clock_find_source(struct snd_usb_audio *chip,
+			      struct usb_host_interface *host_iface,
+			      int entity_id);
+
+#endif /* __USBAUDIO_CLOCK_H */
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 28ee1ce..6f6596c 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -190,6 +190,38 @@ static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
 	return attributes;
 }
 
+static struct uac2_input_terminal_descriptor *
+	snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
+					       int terminal_id)
+{
+	struct uac2_input_terminal_descriptor *term = NULL;
+
+	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
+					       ctrl_iface->extralen,
+					       term, UAC_INPUT_TERMINAL))) {
+		if (term->bTerminalID == terminal_id)
+			return term;
+	}
+
+	return NULL;
+}
+
+static struct uac2_output_terminal_descriptor *
+	snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
+						int terminal_id)
+{
+	struct uac2_output_terminal_descriptor *term = NULL;
+
+	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
+					       ctrl_iface->extralen,
+					       term, UAC_OUTPUT_TERMINAL))) {
+		if (term->bTerminalID == terminal_id)
+			return term;
+	}
+
+	return NULL;
+}
+
 int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
 {
 	struct usb_device *dev;
@@ -199,7 +231,7 @@ int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
 	int i, altno, err, stream;
 	int format = 0, num_channels = 0;
 	struct audioformat *fp = NULL;
-	int num, protocol;
+	int num, protocol, clock = 0;
 	struct uac_format_type_i_continuous_descriptor *fmt;
 
 	dev = chip->dev;
@@ -263,6 +295,8 @@ int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
 		}
 
 		case UAC_VERSION_2: {
+			struct uac2_input_terminal_descriptor *input_term;
+			struct uac2_output_terminal_descriptor *output_term;
 			struct uac_as_header_descriptor_v2 *as =
 				snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
 
@@ -281,7 +315,25 @@ int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
 			num_channels = as->bNrChannels;
 			format = le32_to_cpu(as->bmFormats);
 
-			break;
+			/* lookup the terminal associated to this interface
+			 * to extract the clock */
+			input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
+									    as->bTerminalLink);
+			if (input_term) {
+				clock = input_term->bCSourceID;
+				break;
+			}
+
+			output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
+									      as->bTerminalLink);
+			if (output_term) {
+				clock = output_term->bCSourceID;
+				break;
+			}
+
+			snd_printk(KERN_ERR "%d:%u:%d : bogus bTerminalLink %d\n",
+				   dev->devnum, iface_no, altno, as->bTerminalLink);
+			continue;
 		}
 
 		default:
@@ -338,6 +390,7 @@ int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
 			fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
 					* (fp->maxpacksize & 0x7ff);
 		fp->attributes = parse_uac_endpoint_attributes(chip, alts, protocol, iface_no);
+		fp->clock = clock;
 
 		/* some quirks for attributes here */
 
@@ -374,6 +427,7 @@ int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
 		if (snd_usb_parse_audio_format(chip, fp, format, fmt, stream, alts) < 0) {
 			kfree(fp->rate_table);
 			kfree(fp);
+			fp = NULL;
 			continue;
 		}
 
diff --git a/sound/usb/format.c b/sound/usb/format.c
index fe29d61..30364ab 100644
--- a/sound/usb/format.c
+++ b/sound/usb/format.c
@@ -29,6 +29,7 @@
 #include "quirks.h"
 #include "helper.h"
 #include "debug.h"
+#include "clock.h"
 
 /*
  * parse the audio format type I descriptor
@@ -205,6 +206,60 @@ static int parse_audio_format_rates_v1(struct snd_usb_audio *chip, struct audiof
 }
 
 /*
+ * Helper function to walk the array of sample rate triplets reported by
+ * the device. The problem is that we need to parse whole array first to
+ * get to know how many sample rates we have to expect.
+ * Then fp->rate_table can be allocated and filled.
+ */
+static int parse_uac2_sample_rate_range(struct audioformat *fp, int nr_triplets,
+					const unsigned char *data)
+{
+	int i, nr_rates = 0;
+
+	fp->rates = fp->rate_min = fp->rate_max = 0;
+
+	for (i = 0; i < nr_triplets; i++) {
+		int min = combine_quad(&data[2 + 12 * i]);
+		int max = combine_quad(&data[6 + 12 * i]);
+		int res = combine_quad(&data[10 + 12 * i]);
+		int rate;
+
+		if ((max < 0) || (min < 0) || (res < 0) || (max < min))
+			continue;
+
+		/*
+		 * for ranges with res == 1, we announce a continuous sample
+		 * rate range, and this function should return 0 for no further
+		 * parsing.
+		 */
+		if (res == 1) {
+			fp->rate_min = min;
+			fp->rate_max = max;
+			fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
+			return 0;
+		}
+
+		for (rate = min; rate <= max; rate += res) {
+			if (fp->rate_table)
+				fp->rate_table[nr_rates] = rate;
+			if (!fp->rate_min || rate < fp->rate_min)
+				fp->rate_min = rate;
+			if (!fp->rate_max || rate > fp->rate_max)
+				fp->rate_max = rate;
+			fp->rates |= snd_pcm_rate_to_rate_bit(rate);
+
+			nr_rates++;
+
+			/* avoid endless loop */
+			if (res == 0)
+				break;
+		}
+	}
+
+	return nr_rates;
+}
+
+/*
  * parse the format descriptor and stores the possible sample rates
  * on the audioformat table (audio class v2).
  */
@@ -214,21 +269,30 @@ static int parse_audio_format_rates_v2(struct snd_usb_audio *chip,
 {
 	struct usb_device *dev = chip->dev;
 	unsigned char tmp[2], *data;
-	int i, nr_rates, data_size, ret = 0;
+	int nr_triplets, data_size, ret = 0;
+	int clock = snd_usb_clock_find_source(chip, chip->ctrl_intf, fp->clock);
+
+	if (clock < 0) {
+		snd_printk(KERN_ERR "%s(): unable to find clock source (clock %d)\n",
+				__func__, clock);
+		goto err;
+	}
 
 	/* get the number of sample rates first by only fetching 2 bytes */
 	ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_RANGE,
 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
-			      UAC2_CS_CONTROL_SAM_FREQ << 8, chip->clock_id << 8,
+			      UAC2_CS_CONTROL_SAM_FREQ << 8,
+			      snd_usb_ctrl_intf(chip) | (clock << 8),
 			      tmp, sizeof(tmp), 1000);
 
 	if (ret < 0) {
-		snd_printk(KERN_ERR "unable to retrieve number of sample rates\n");
+		snd_printk(KERN_ERR "%s(): unable to retrieve number of sample rates (clock %d)\n",
+				__func__, clock);
 		goto err;
 	}
 
-	nr_rates = (tmp[1] << 8) | tmp[0];
-	data_size = 2 + 12 * nr_rates;
+	nr_triplets = (tmp[1] << 8) | tmp[0];
+	data_size = 2 + 12 * nr_triplets;
 	data = kzalloc(data_size, GFP_KERNEL);
 	if (!data) {
 		ret = -ENOMEM;
@@ -237,36 +301,40 @@ static int parse_audio_format_rates_v2(struct snd_usb_audio *chip,
 
 	/* now get the full information */
 	ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_RANGE,
-			       USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
-			       UAC2_CS_CONTROL_SAM_FREQ << 8, chip->clock_id << 8,
-			       data, data_size, 1000);
+			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
+			      UAC2_CS_CONTROL_SAM_FREQ << 8,
+			      snd_usb_ctrl_intf(chip) | (clock << 8),
+			      data, data_size, 1000);
 
 	if (ret < 0) {
-		snd_printk(KERN_ERR "unable to retrieve sample rate range\n");
+		snd_printk(KERN_ERR "%s(): unable to retrieve sample rate range (clock %d)\n",
+				__func__, clock);
 		ret = -EINVAL;
 		goto err_free;
 	}
 
-	fp->rate_table = kmalloc(sizeof(int) * nr_rates, GFP_KERNEL);
+	/* Call the triplet parser, and make sure fp->rate_table is NULL.
+	 * We just use the return value to know how many sample rates we
+	 * will have to deal with. */
+	kfree(fp->rate_table);
+	fp->rate_table = NULL;
+	fp->nr_rates = parse_uac2_sample_rate_range(fp, nr_triplets, data);
+
+	if (fp->nr_rates == 0) {
+		/* SNDRV_PCM_RATE_CONTINUOUS */
+		ret = 0;
+		goto err_free;
+	}
+
+	fp->rate_table = kmalloc(sizeof(int) * fp->nr_rates, GFP_KERNEL);
 	if (!fp->rate_table) {
 		ret = -ENOMEM;
 		goto err_free;
 	}
 
-	fp->nr_rates = 0;
-	fp->rate_min = fp->rate_max = 0;
-
-	for (i = 0; i < nr_rates; i++) {
-		int rate = combine_quad(&data[2 + 12 * i]);
-
-		fp->rate_table[fp->nr_rates] = rate;
-		if (!fp->rate_min || rate < fp->rate_min)
-			fp->rate_min = rate;
-		if (!fp->rate_max || rate > fp->rate_max)
-			fp->rate_max = rate;
-		fp->rates |= snd_pcm_rate_to_rate_bit(rate);
-		fp->nr_rates++;
-	}
+	/* Call the triplet parser again, but this time, fp->rate_table is
+	 * allocated, so the rates will be stored */
+	parse_uac2_sample_rate_range(fp, nr_triplets, data);
 
 err_free:
 	kfree(data);
diff --git a/sound/usb/helper.h b/sound/usb/helper.h
index a6b0e51..09bd943 100644
--- a/sound/usb/helper.h
+++ b/sound/usb/helper.h
@@ -28,5 +28,9 @@ unsigned char snd_usb_parse_datainterval(struct snd_usb_audio *chip,
 #define snd_usb_get_speed(dev) ((dev)->speed)
 #endif
 
+static inline int snd_usb_ctrl_intf(struct snd_usb_audio *chip)
+{
+	return get_iface_desc(chip->ctrl_intf)->bInterfaceNumber;
+}
 
 #endif /* __USBAUDIO_HELPER_H */
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 03ce971..736d134 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -78,39 +78,6 @@ enum {
 	USB_MIXER_U16,
 };
 
-enum {
-	USB_PROC_UPDOWN = 1,
-	USB_PROC_UPDOWN_SWITCH = 1,
-	USB_PROC_UPDOWN_MODE_SEL = 2,
-
-	USB_PROC_PROLOGIC = 2,
-	USB_PROC_PROLOGIC_SWITCH = 1,
-	USB_PROC_PROLOGIC_MODE_SEL = 2,
-
-	USB_PROC_3DENH = 3,
-	USB_PROC_3DENH_SWITCH = 1,
-	USB_PROC_3DENH_SPACE = 2,
-
-	USB_PROC_REVERB = 4,
-	USB_PROC_REVERB_SWITCH = 1,
-	USB_PROC_REVERB_LEVEL = 2,
-	USB_PROC_REVERB_TIME = 3,
-	USB_PROC_REVERB_DELAY = 4,
-
-	USB_PROC_CHORUS = 5,
-	USB_PROC_CHORUS_SWITCH = 1,
-	USB_PROC_CHORUS_LEVEL = 2,
-	USB_PROC_CHORUS_RATE = 3,
-	USB_PROC_CHORUS_DEPTH = 4,
-
-	USB_PROC_DCR = 6,
-	USB_PROC_DCR_SWITCH = 1,
-	USB_PROC_DCR_RATIO = 2,
-	USB_PROC_DCR_MAX_AMP = 3,
-	USB_PROC_DCR_THRESHOLD = 4,
-	USB_PROC_DCR_ATTACK = 5,
-	USB_PROC_DCR_RELEASE = 6,
-};
 
 /*E-mu 0202(0404) eXtension Unit(XU) control*/
 enum {
@@ -198,22 +165,24 @@ static int check_mapped_selector_name(struct mixer_build *state, int unitid,
 
 /*
  * find an audio control unit with the given unit id
- * this doesn't return any clock related units, so they need to be handled elsewhere
  */
 static void *find_audio_control_unit(struct mixer_build *state, unsigned char unit)
 {
-	unsigned char *p;
+	/* we just parse the header */
+	struct uac_feature_unit_descriptor *hdr = NULL;
 
-	p = NULL;
-	while ((p = snd_usb_find_desc(state->buffer, state->buflen, p,
-				      USB_DT_CS_INTERFACE)) != NULL) {
-		if (p[0] >= 4 && p[2] >= UAC_INPUT_TERMINAL && p[2] <= UAC2_EXTENSION_UNIT_V2 && p[3] == unit)
-			return p;
+	while ((hdr = snd_usb_find_desc(state->buffer, state->buflen, hdr,
+					USB_DT_CS_INTERFACE)) != NULL) {
+		if (hdr->bLength >= 4 &&
+		    hdr->bDescriptorSubtype >= UAC_INPUT_TERMINAL &&
+		    hdr->bDescriptorSubtype <= UAC2_SAMPLE_RATE_CONVERTER &&
+		    hdr->bUnitID == unit)
+			return hdr;
 	}
+
 	return NULL;
 }
 
-
 /*
  * copy a string with the given id
  */
@@ -328,27 +297,36 @@ static int get_ctl_value_v1(struct usb_mixer_elem_info *cval, int request, int v
 
 static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request, int validx, int *value_ret)
 {
-	unsigned char buf[14]; /* enough space for one range of 4 bytes */
+	unsigned char buf[2 + 3*sizeof(__u16)]; /* enough space for one range */
 	unsigned char *val;
-	int ret;
+	int ret, size;
 	__u8 bRequest;
 
-	bRequest = (request == UAC_GET_CUR) ?
-		UAC2_CS_CUR : UAC2_CS_RANGE;
+	if (request == UAC_GET_CUR) {
+		bRequest = UAC2_CS_CUR;
+		size = sizeof(__u16);
+	} else {
+		bRequest = UAC2_CS_RANGE;
+		size = sizeof(buf);
+	}
+
+	memset(buf, 0, sizeof(buf));
 
 	ret = snd_usb_ctl_msg(cval->mixer->chip->dev,
 			      usb_rcvctrlpipe(cval->mixer->chip->dev, 0),
 			      bRequest,
 			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
 			      validx, cval->mixer->ctrlif | (cval->id << 8),
-			      buf, sizeof(buf), 1000);
+			      buf, size, 1000);
 
 	if (ret < 0) {
-		snd_printdd(KERN_ERR "cannot get ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d\n",
-			    request, validx, cval->mixer->ctrlif | (cval->id << 8), cval->val_type);
+		snd_printk(KERN_ERR "cannot get ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d\n",
+			   request, validx, cval->mixer->ctrlif | (cval->id << 8), cval->val_type);
 		return ret;
 	}
 
+	/* FIXME: how should we handle multiple triplets here? */
+
 	switch (request) {
 	case UAC_GET_CUR:
 		val = buf;
@@ -462,6 +440,16 @@ static int set_cur_mix_value(struct usb_mixer_elem_info *cval, int channel,
 			     int index, int value)
 {
 	int err;
+	unsigned int read_only = (channel == 0) ?
+		cval->master_readonly :
+		cval->ch_readonly & (1 << (channel - 1));
+
+	if (read_only) {
+		snd_printdd(KERN_INFO "%s(): channel %d of control %d is read_only\n",
+			    __func__, channel, cval->control);
+		return 0;
+	}
+
 	err = snd_usb_mixer_set_ctl_value(cval, UAC_SET_CUR, (cval->control << 8) | channel,
 			    value);
 	if (err < 0)
@@ -631,6 +619,7 @@ static int get_term_name(struct mixer_build *state, struct usb_audio_term *iterm
  */
 static int check_input_term(struct mixer_build *state, int id, struct usb_audio_term *term)
 {
+	int err;
 	void *p1;
 
 	memset(term, 0, sizeof(*term));
@@ -651,6 +640,11 @@ static int check_input_term(struct mixer_build *state, int id, struct usb_audio_
 				term->channels = d->bNrChannels;
 				term->chconfig = le32_to_cpu(d->bmChannelConfig);
 				term->name = d->iTerminal;
+
+				/* call recursively to get the clock selectors */
+				err = check_input_term(state, d->bCSourceID, term);
+				if (err < 0)
+					return err;
 			}
 			return 0;
 		case UAC_FEATURE_UNIT: {
@@ -667,7 +661,8 @@ static int check_input_term(struct mixer_build *state, int id, struct usb_audio_
 			term->name = uac_mixer_unit_iMixer(d);
 			return 0;
 		}
-		case UAC_SELECTOR_UNIT: {
+		case UAC_SELECTOR_UNIT:
+		case UAC2_CLOCK_SELECTOR: {
 			struct uac_selector_unit_descriptor *d = p1;
 			/* call recursively to retrieve the channel info */
 			if (check_input_term(state, d->baSourceID[0], term) < 0)
@@ -690,6 +685,13 @@ static int check_input_term(struct mixer_build *state, int id, struct usb_audio_
 			term->name = uac_processing_unit_iProcessing(d, state->mixer->protocol);
 			return 0;
 		}
+		case UAC2_CLOCK_SOURCE: {
+			struct uac_clock_source_descriptor *d = p1;
+			term->type = d->bDescriptorSubtype << 16; /* virtual type */
+			term->id = id;
+			term->name = d->iClockSource;
+			return 0;
+		}
 		default:
 			return -ENODEV;
 		}
@@ -709,16 +711,20 @@ struct usb_feature_control_info {
 };
 
 static struct usb_feature_control_info audio_feature_info[] = {
-	{ "Mute",		USB_MIXER_INV_BOOLEAN },
-	{ "Volume",		USB_MIXER_S16 },
+	{ "Mute",			USB_MIXER_INV_BOOLEAN },
+	{ "Volume",			USB_MIXER_S16 },
 	{ "Tone Control - Bass",	USB_MIXER_S8 },
 	{ "Tone Control - Mid",		USB_MIXER_S8 },
 	{ "Tone Control - Treble",	USB_MIXER_S8 },
 	{ "Graphic Equalizer",		USB_MIXER_S8 }, /* FIXME: not implemeted yet */
-	{ "Auto Gain Control",	USB_MIXER_BOOLEAN },
-	{ "Delay Control",	USB_MIXER_U16 },
-	{ "Bass Boost",		USB_MIXER_BOOLEAN },
-	{ "Loudness",		USB_MIXER_BOOLEAN },
+	{ "Auto Gain Control",		USB_MIXER_BOOLEAN },
+	{ "Delay Control",		USB_MIXER_U16 },
+	{ "Bass Boost",			USB_MIXER_BOOLEAN },
+	{ "Loudness",			USB_MIXER_BOOLEAN },
+	/* UAC2 specific */
+	{ "Input Gain Control",		USB_MIXER_U16 },
+	{ "Input Gain Pad Control",	USB_MIXER_BOOLEAN },
+	{ "Phase Inverter Control",	USB_MIXER_BOOLEAN },
 };
 
 
@@ -958,7 +964,7 @@ static size_t append_ctl_name(struct snd_kcontrol *kctl, const char *str)
 static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
 			      unsigned int ctl_mask, int control,
 			      struct usb_audio_term *iterm, int unitid,
-			      int read_only)
+			      int readonly_mask)
 {
 	struct uac_feature_unit_descriptor *desc = raw_desc;
 	unsigned int len = 0;
@@ -970,7 +976,7 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
 
 	control++; /* change from zero-based to 1-based value */
 
-	if (control == UAC_GRAPHIC_EQUALIZER_CONTROL) {
+	if (control == UAC_FU_GRAPHIC_EQUALIZER) {
 		/* FIXME: not supported yet */
 		return;
 	}
@@ -989,20 +995,25 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
 	cval->control = control;
 	cval->cmask = ctl_mask;
 	cval->val_type = audio_feature_info[control-1].type;
-	if (ctl_mask == 0)
+	if (ctl_mask == 0) {
 		cval->channels = 1;	/* master channel */
-	else {
+		cval->master_readonly = readonly_mask;
+	} else {
 		int i, c = 0;
 		for (i = 0; i < 16; i++)
 			if (ctl_mask & (1 << i))
 				c++;
 		cval->channels = c;
+		cval->ch_readonly = readonly_mask;
 	}
 
 	/* get min/max values */
 	get_min_max(cval, 0);
 
-	if (read_only)
+	/* if all channels in the mask are marked read-only, make the control
+	 * read-only. set_cur_mix_value() will check the mask again and won't
+	 * issue write commands to read-only channels. */
+	if (cval->channels == readonly_mask)
 		kctl = snd_ctl_new1(&usb_feature_unit_ctl_ro, cval);
 	else
 		kctl = snd_ctl_new1(&usb_feature_unit_ctl, cval);
@@ -1021,8 +1032,8 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
 				kctl->id.name, sizeof(kctl->id.name));
 
 	switch (control) {
-	case UAC_MUTE_CONTROL:
-	case UAC_VOLUME_CONTROL:
+	case UAC_FU_MUTE:
+	case UAC_FU_VOLUME:
 		/* determine the control name.  the rule is:
 		 * - if a name id is given in descriptor, use it.
 		 * - if the connected input can be determined, then use the name
@@ -1049,9 +1060,9 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
 				len = append_ctl_name(kctl, " Playback");
 			}
 		}
-		append_ctl_name(kctl, control == UAC_MUTE_CONTROL ?
+		append_ctl_name(kctl, control == UAC_FU_MUTE ?
 				" Switch" : " Volume");
-		if (control == UAC_VOLUME_CONTROL) {
+		if (control == UAC_FU_VOLUME) {
 			kctl->tlv.c = mixer_vol_tlv;
 			kctl->vd[0].access |= 
 				SNDRV_CTL_ELEM_ACCESS_TLV_READ |
@@ -1096,6 +1107,19 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
 		}
 		break;
 
+	case USB_ID(0x046d, 0x0809):
+	case USB_ID(0x046d, 0x0991):
+	/* Most audio usb devices lie about volume resolution.
+	 * Most Logitech webcams have res = 384.
+	 * Proboly there is some logitech magic behind this number --fishor
+	 */
+		if (!strcmp(kctl->id.name, "Mic Capture Volume")) {
+			snd_printk(KERN_INFO
+				"set resolution quirk: cval->res = 384\n");
+			cval->res = 384;
+		}
+		break;
+
 	}
 
 	snd_printdd(KERN_INFO "[%d] FU [%s] ch = %d, val = %d/%d/%d\n",
@@ -1150,7 +1174,7 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, void
 		snd_printk(KERN_INFO
 			   "usbmixer: master volume quirk for PCM2702 chip\n");
 		/* disable non-functional volume control */
-		master_bits &= ~UAC_FU_VOLUME;
+		master_bits &= ~UAC_CONTROL_BIT(UAC_FU_VOLUME);
 		break;
 	}
 	if (channels > 0)
@@ -1188,19 +1212,22 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, void
 
 			for (j = 0; j < channels; j++) {
 				unsigned int mask = snd_usb_combine_bytes(bmaControls + csize * (j+1), csize);
-				if (mask & (1 << (i * 2))) {
+				if (uac2_control_is_readable(mask, i)) {
 					ch_bits |= (1 << j);
-					if (~mask & (1 << ((i * 2) + 1)))
+					if (!uac2_control_is_writeable(mask, i))
 						ch_read_only |= (1 << j);
 				}
 			}
 
-			/* FIXME: the whole unit is read-only if any of the channels is marked read-only */
+			/* NOTE: build_feature_ctl() will mark the control read-only if all channels
+			 * are marked read-only in the descriptors. Otherwise, the control will be
+			 * reported as writeable, but the driver will not actually issue a write
+			 * command for read-only channels */
 			if (ch_bits & 1) /* the first channel must be set (for ease of programming) */
-				build_feature_ctl(state, _ftr, ch_bits, i, &iterm, unitid, !!ch_read_only);
-			if (master_bits & (1 << i * 2))
+				build_feature_ctl(state, _ftr, ch_bits, i, &iterm, unitid, ch_read_only);
+			if (uac2_control_is_readable(master_bits, i))
 				build_feature_ctl(state, _ftr, 0, i, &iterm, unitid,
-						  ~master_bits & (1 << ((i * 2) + 1)));
+						  !uac2_control_is_writeable(master_bits, i));
 		}
 	}
 
@@ -1392,51 +1419,51 @@ struct procunit_info {
 };
 
 static struct procunit_value_info updown_proc_info[] = {
-	{ USB_PROC_UPDOWN_SWITCH, "Switch", USB_MIXER_BOOLEAN },
-	{ USB_PROC_UPDOWN_MODE_SEL, "Mode Select", USB_MIXER_U8, 1 },
+	{ UAC_UD_ENABLE, "Switch", USB_MIXER_BOOLEAN },
+	{ UAC_UD_MODE_SELECT, "Mode Select", USB_MIXER_U8, 1 },
 	{ 0 }
 };
 static struct procunit_value_info prologic_proc_info[] = {
-	{ USB_PROC_PROLOGIC_SWITCH, "Switch", USB_MIXER_BOOLEAN },
-	{ USB_PROC_PROLOGIC_MODE_SEL, "Mode Select", USB_MIXER_U8, 1 },
+	{ UAC_DP_ENABLE, "Switch", USB_MIXER_BOOLEAN },
+	{ UAC_DP_MODE_SELECT, "Mode Select", USB_MIXER_U8, 1 },
 	{ 0 }
 };
 static struct procunit_value_info threed_enh_proc_info[] = {
-	{ USB_PROC_3DENH_SWITCH, "Switch", USB_MIXER_BOOLEAN },
-	{ USB_PROC_3DENH_SPACE, "Spaciousness", USB_MIXER_U8 },
+	{ UAC_3D_ENABLE, "Switch", USB_MIXER_BOOLEAN },
+	{ UAC_3D_SPACE, "Spaciousness", USB_MIXER_U8 },
 	{ 0 }
 };
 static struct procunit_value_info reverb_proc_info[] = {
-	{ USB_PROC_REVERB_SWITCH, "Switch", USB_MIXER_BOOLEAN },
-	{ USB_PROC_REVERB_LEVEL, "Level", USB_MIXER_U8 },
-	{ USB_PROC_REVERB_TIME, "Time", USB_MIXER_U16 },
-	{ USB_PROC_REVERB_DELAY, "Delay", USB_MIXER_U8 },
+	{ UAC_REVERB_ENABLE, "Switch", USB_MIXER_BOOLEAN },
+	{ UAC_REVERB_LEVEL, "Level", USB_MIXER_U8 },
+	{ UAC_REVERB_TIME, "Time", USB_MIXER_U16 },
+	{ UAC_REVERB_FEEDBACK, "Feedback", USB_MIXER_U8 },
 	{ 0 }
 };
 static struct procunit_value_info chorus_proc_info[] = {
-	{ USB_PROC_CHORUS_SWITCH, "Switch", USB_MIXER_BOOLEAN },
-	{ USB_PROC_CHORUS_LEVEL, "Level", USB_MIXER_U8 },
-	{ USB_PROC_CHORUS_RATE, "Rate", USB_MIXER_U16 },
-	{ USB_PROC_CHORUS_DEPTH, "Depth", USB_MIXER_U16 },
+	{ UAC_CHORUS_ENABLE, "Switch", USB_MIXER_BOOLEAN },
+	{ UAC_CHORUS_LEVEL, "Level", USB_MIXER_U8 },
+	{ UAC_CHORUS_RATE, "Rate", USB_MIXER_U16 },
+	{ UAC_CHORUS_DEPTH, "Depth", USB_MIXER_U16 },
 	{ 0 }
 };
 static struct procunit_value_info dcr_proc_info[] = {
-	{ USB_PROC_DCR_SWITCH, "Switch", USB_MIXER_BOOLEAN },
-	{ USB_PROC_DCR_RATIO, "Ratio", USB_MIXER_U16 },
-	{ USB_PROC_DCR_MAX_AMP, "Max Amp", USB_MIXER_S16 },
-	{ USB_PROC_DCR_THRESHOLD, "Threshold", USB_MIXER_S16 },
-	{ USB_PROC_DCR_ATTACK, "Attack Time", USB_MIXER_U16 },
-	{ USB_PROC_DCR_RELEASE, "Release Time", USB_MIXER_U16 },
+	{ UAC_DCR_ENABLE, "Switch", USB_MIXER_BOOLEAN },
+	{ UAC_DCR_RATE, "Ratio", USB_MIXER_U16 },
+	{ UAC_DCR_MAXAMPL, "Max Amp", USB_MIXER_S16 },
+	{ UAC_DCR_THRESHOLD, "Threshold", USB_MIXER_S16 },
+	{ UAC_DCR_ATTACK_TIME, "Attack Time", USB_MIXER_U16 },
+	{ UAC_DCR_RELEASE_TIME, "Release Time", USB_MIXER_U16 },
 	{ 0 }
 };
 
 static struct procunit_info procunits[] = {
-	{ USB_PROC_UPDOWN, "Up Down", updown_proc_info },
-	{ USB_PROC_PROLOGIC, "Dolby Prologic", prologic_proc_info },
-	{ USB_PROC_3DENH, "3D Stereo Extender", threed_enh_proc_info },
-	{ USB_PROC_REVERB, "Reverb", reverb_proc_info },
-	{ USB_PROC_CHORUS, "Chorus", chorus_proc_info },
-	{ USB_PROC_DCR, "DCR", dcr_proc_info },
+	{ UAC_PROCESS_UP_DOWNMIX, "Up Down", updown_proc_info },
+	{ UAC_PROCESS_DOLBY_PROLOGIC, "Dolby Prologic", prologic_proc_info },
+	{ UAC_PROCESS_STEREO_EXTENDER, "3D Stereo Extender", threed_enh_proc_info },
+	{ UAC_PROCESS_REVERB, "Reverb", reverb_proc_info },
+	{ UAC_PROCESS_CHORUS, "Chorus", chorus_proc_info },
+	{ UAC_PROCESS_DYN_RANGE_COMP, "DCR", dcr_proc_info },
 	{ 0 },
 };
 /*
@@ -1524,7 +1551,7 @@ static int build_audio_procunit(struct mixer_build *state, int unitid, void *raw
 		cval->channels = 1;
 
 		/* get min/max values */
-		if (type == USB_PROC_UPDOWN && cval->control == USB_PROC_UPDOWN_MODE_SEL) {
+		if (type == UAC_PROCESS_UP_DOWNMIX && cval->control == UAC_UD_MODE_SELECT) {
 			__u8 *control_spec = uac_processing_unit_specific(desc, state->mixer->protocol);
 			/* FIXME: hard-coded */
 			cval->min = 1;
@@ -1619,7 +1646,7 @@ static int mixer_ctl_selector_get(struct snd_kcontrol *kcontrol, struct snd_ctl_
 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
 	int val, err;
 
-	err = get_cur_ctl_value(cval, 0, &val);
+	err = get_cur_ctl_value(cval, cval->control << 8, &val);
 	if (err < 0) {
 		if (cval->mixer->ignore_ctl_error) {
 			ucontrol->value.enumerated.item[0] = 0;
@@ -1638,7 +1665,7 @@ static int mixer_ctl_selector_put(struct snd_kcontrol *kcontrol, struct snd_ctl_
 	struct usb_mixer_elem_info *cval = kcontrol->private_data;
 	int val, oval, err;
 
-	err = get_cur_ctl_value(cval, 0, &oval);
+	err = get_cur_ctl_value(cval, cval->control << 8, &oval);
 	if (err < 0) {
 		if (cval->mixer->ignore_ctl_error)
 			return 0;
@@ -1647,7 +1674,7 @@ static int mixer_ctl_selector_put(struct snd_kcontrol *kcontrol, struct snd_ctl_
 	val = ucontrol->value.enumerated.item[0];
 	val = get_abs_value(cval, val);
 	if (val != oval) {
-		set_cur_ctl_value(cval, 0, val);
+		set_cur_ctl_value(cval, cval->control << 8, val);
 		return 1;
 	}
 	return 0;
@@ -1729,6 +1756,11 @@ static int parse_audio_selector_unit(struct mixer_build *state, int unitid, void
 	cval->res = 1;
 	cval->initialized = 1;
 
+	if (desc->bDescriptorSubtype == UAC2_CLOCK_SELECTOR)
+		cval->control = UAC2_CX_CLOCK_SELECTOR;
+	else
+		cval->control = 0;
+
 	namelist = kmalloc(sizeof(char *) * desc->bNrInPins, GFP_KERNEL);
 	if (! namelist) {
 		snd_printk(KERN_ERR "cannot malloc\n");
@@ -1778,7 +1810,9 @@ static int parse_audio_selector_unit(struct mixer_build *state, int unitid, void
 		if (! len)
 			strlcpy(kctl->id.name, "USB", sizeof(kctl->id.name));
 
-		if ((state->oterm.type & 0xff00) == 0x0100)
+		if (desc->bDescriptorSubtype == UAC2_CLOCK_SELECTOR)
+			append_ctl_name(kctl, " Clock Source");
+		else if ((state->oterm.type & 0xff00) == 0x0100)
 			append_ctl_name(kctl, " Capture Source");
 		else
 			append_ctl_name(kctl, " Playback Source");
@@ -1812,10 +1846,12 @@ static int parse_audio_unit(struct mixer_build *state, int unitid)
 
 	switch (p1[2]) {
 	case UAC_INPUT_TERMINAL:
+	case UAC2_CLOCK_SOURCE:
 		return 0; /* NOP */
 	case UAC_MIXER_UNIT:
 		return parse_audio_mixer_unit(state, unitid, p1);
 	case UAC_SELECTOR_UNIT:
+	case UAC2_CLOCK_SELECTOR:
 		return parse_audio_selector_unit(state, unitid, p1);
 	case UAC_FEATURE_UNIT:
 		return parse_audio_feature_unit(state, unitid, p1);
@@ -1912,6 +1948,11 @@ static int snd_usb_mixer_controls(struct usb_mixer_interface *mixer)
 			err = parse_audio_unit(&state, desc->bSourceID);
 			if (err < 0)
 				return err;
+
+			/* for UAC2, use the same approach to also add the clock selectors */
+			err = parse_audio_unit(&state, desc->bCSourceID);
+			if (err < 0)
+				return err;
 		}
 	}
 
diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h
index 1301238..a7cf100 100644
--- a/sound/usb/mixer.h
+++ b/sound/usb/mixer.h
@@ -34,6 +34,8 @@ struct usb_mixer_elem_info {
 	unsigned int id;
 	unsigned int control;	/* CS or ICN (high byte) */
 	unsigned int cmask; /* channel mask bitmap: 0 = master */
+	unsigned int ch_readonly;
+	unsigned int master_readonly;
 	int channels;
 	int val_type;
 	int min, max, res;
diff --git a/sound/usb/mixer_maps.c b/sound/usb/mixer_maps.c
index d93fc89..f1324c4 100644
--- a/sound/usb/mixer_maps.c
+++ b/sound/usb/mixer_maps.c
@@ -85,8 +85,8 @@ static struct usbmix_name_map extigy_map[] = {
 	/* 16: MU (w/o controls) */
 	{ 17, NULL, 1 }, /* DISABLED: PU-switch (any effect?) */
 	{ 17, "Channel Routing", 2 },	/* PU: mode select */
-	{ 18, "Tone Control - Bass", UAC_BASS_CONTROL }, /* FU */
-	{ 18, "Tone Control - Treble", UAC_TREBLE_CONTROL }, /* FU */
+	{ 18, "Tone Control - Bass", UAC_FU_BASS }, /* FU */
+	{ 18, "Tone Control - Treble", UAC_FU_TREBLE }, /* FU */
 	{ 18, "Master Playback" }, /* FU; others */
 	/* 19: OT speaker */
 	/* 20: OT headphone */
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 056587d..4568298 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -31,6 +31,7 @@
 #include "urb.h"
 #include "helper.h"
 #include "pcm.h"
+#include "clock.h"
 
 /*
  * return the current pcm pointer.  just based on the hwptr_done value.
@@ -181,103 +182,6 @@ int snd_usb_init_pitch(struct snd_usb_audio *chip, int iface,
 	return -EINVAL;
 }
 
-static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
-			      struct usb_host_interface *alts,
-			      struct audioformat *fmt, int rate)
-{
-	struct usb_device *dev = chip->dev;
-	unsigned int ep;
-	unsigned char data[3];
-	int err, crate;
-
-	ep = get_endpoint(alts, 0)->bEndpointAddress;
-	/* if endpoint doesn't have sampling rate control, bail out */
-	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE)) {
-		snd_printk(KERN_WARNING "%d:%d:%d: endpoint lacks sample rate attribute bit, cannot set.\n",
-				   dev->devnum, iface, fmt->altsetting);
-		return 0;
-	}
-
-	data[0] = rate;
-	data[1] = rate >> 8;
-	data[2] = rate >> 16;
-	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
-				   USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT,
-				   UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
-				   data, sizeof(data), 1000)) < 0) {
-		snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n",
-			   dev->devnum, iface, fmt->altsetting, rate, ep);
-		return err;
-	}
-	if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
-				   USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_IN,
-				   UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
-				   data, sizeof(data), 1000)) < 0) {
-		snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n",
-			   dev->devnum, iface, fmt->altsetting, ep);
-		return 0; /* some devices don't support reading */
-	}
-	crate = data[0] | (data[1] << 8) | (data[2] << 16);
-	if (crate != rate) {
-		snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
-		// runtime->rate = crate;
-	}
-
-	return 0;
-}
-
-static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
-			      struct usb_host_interface *alts,
-			      struct audioformat *fmt, int rate)
-{
-	struct usb_device *dev = chip->dev;
-	unsigned char data[4];
-	int err, crate;
-
-	data[0] = rate;
-	data[1] = rate >> 8;
-	data[2] = rate >> 16;
-	data[3] = rate >> 24;
-	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
-				   USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
-				   UAC2_CS_CONTROL_SAM_FREQ << 8, chip->clock_id << 8,
-				   data, sizeof(data), 1000)) < 0) {
-		snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2)\n",
-			   dev->devnum, iface, fmt->altsetting, rate);
-		return err;
-	}
-	if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
-				   USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
-				   UAC2_CS_CONTROL_SAM_FREQ << 8, chip->clock_id << 8,
-				   data, sizeof(data), 1000)) < 0) {
-		snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2)\n",
-			   dev->devnum, iface, fmt->altsetting);
-		return err;
-	}
-	crate = data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
-	if (crate != rate)
-		snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
-
-	return 0;
-}
-
-int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
-			     struct usb_host_interface *alts,
-			     struct audioformat *fmt, int rate)
-{
-	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
-
-	switch (altsd->bInterfaceProtocol) {
-	case UAC_VERSION_1:
-		return set_sample_rate_v1(chip, iface, alts, fmt, rate);
-
-	case UAC_VERSION_2:
-		return set_sample_rate_v2(chip, iface, alts, fmt, rate);
-	}
-
-	return -EINVAL;
-}
-
 /*
  * find a matching format and set up the interface
  */
diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
index 06ebf24..24d3319 100644
--- a/sound/usb/usbaudio.h
+++ b/sound/usb/usbaudio.h
@@ -40,9 +40,6 @@ struct snd_usb_audio {
 	int num_interfaces;
 	int num_suspended_intf;
 
-	/* for audio class v2 */
-	int clock_id;
-
 	struct list_head pcm_list;	/* list of pcm streams */
 	int pcm_devs;
 
@@ -53,6 +50,8 @@ struct snd_usb_audio {
 	int setup;			/* from the 'device_setup' module param */
 	int nrpacks;			/* from the 'nrpacks' module param */
 	int async_unlink;		/* from the 'async_unlink' module param */
+
+	struct usb_host_interface *ctrl_intf;	/* the audio control interface */
 };
 
 /*