ALSA: usb-audio: add support for samplerate setting on v2 devices

Sample rate setting is done with a 4-byte long class request that
addresses the interface.
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/endpoint.c

@@ -350,8 +350,8 @@ int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
 		}
 		/* try to set the interface... */
 		usb_set_interface(chip->dev, iface_no, altno);
-		snd_usb_init_pitch(chip->dev, iface_no, alts, fp);
-		snd_usb_init_sample_rate(chip->dev, iface_no, alts, fp, fp->rate_max);
+		snd_usb_init_pitch(chip, iface_no, alts, fp);
+		snd_usb_init_sample_rate(chip, iface_no, alts, fp, fp->rate_max);
 	}
 	return 0;
 }

sound/usb/pcm.c

@@ -107,58 +107,87 @@ static struct audioformat *find_format(struct snd_usb_substream *subs, unsigned
 	return found;
 }
 
-
-/*
- * initialize the picth control and sample rate
- */
-int snd_usb_init_pitch(struct usb_device *dev, int iface,
+static int init_pitch_v1(struct snd_usb_audio *chip, int iface,
 			 struct usb_host_interface *alts,
 			 struct audioformat *fmt)
 {
+	struct usb_device *dev = chip->dev;
 	unsigned int ep;
 	unsigned char data[1];
 	int err;
 
 	ep = get_endpoint(alts, 0)->bEndpointAddress;
-	/* if endpoint has pitch control, enable it */
-	if (fmt->attributes & UAC_EP_CS_ATTR_PITCH_CONTROL) {
+
+	/* if endpoint doesn't have pitch control, bail out */
+	if (!(fmt->attributes & UAC_EP_CS_ATTR_PITCH_CONTROL))
+		return 0;
+
 	data[0] = 1;
 	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_PITCH_CONTROL << 8, ep, data, 1, 1000)) < 0) {
+				   UAC_EP_CS_ATTR_PITCH_CONTROL << 8, ep,
+				   data, sizeof(data), 1000)) < 0) {
 		snd_printk(KERN_ERR "%d:%d:%d: cannot set enable PITCH\n",
 			   dev->devnum, iface, ep);
 		return err;
 	}
-	}
+
 	return 0;
 }
 
-int snd_usb_init_sample_rate(struct usb_device *dev, int iface,
+/*
+ * initialize the picth control and sample rate
+ */
+int snd_usb_init_pitch(struct snd_usb_audio *chip, int iface,
+		       struct usb_host_interface *alts,
+		       struct audioformat *fmt)
+{
+	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
+
+	switch (altsd->bInterfaceProtocol) {
+	case UAC_VERSION_1:
+		return init_pitch_v1(chip, iface, alts, fmt);
+
+	case UAC_VERSION_2:
+		/* not implemented yet */
+		return 0;
+	}
+
+	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;
+	int err, crate;
 
 	ep = get_endpoint(alts, 0)->bEndpointAddress;
-	/* if endpoint has sampling rate control, set it */
-	if (fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE) {
-		int crate;
+	/* 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, 3, 1000)) < 0) {
+				   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, 3, 1000)) < 0) {
+				   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 */
@@ -168,10 +197,62 @@ int snd_usb_init_sample_rate(struct usb_device *dev, int iface,
 		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,
+				   0x0100, 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,
+				   0x0100, 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
  */
@@ -280,7 +361,7 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
 	if (fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX)
 		subs->fill_max = 1;
 
-	if ((err = snd_usb_init_pitch(dev, subs->interface, alts, fmt)) < 0)
+	if ((err = snd_usb_init_pitch(subs->stream->chip, subs->interface, alts, fmt)) < 0)
 		return err;
 
 	subs->cur_audiofmt = fmt;
@@ -343,7 +424,7 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 		struct usb_interface *iface;
 		iface = usb_ifnum_to_if(subs->dev, fmt->iface);
 		alts = &iface->altsetting[fmt->altset_idx];
-		ret = snd_usb_init_sample_rate(subs->dev, subs->interface, alts, fmt, rate);
+		ret = snd_usb_init_sample_rate(subs->stream->chip, subs->interface, alts, fmt, rate);
 		if (ret < 0)
 			return ret;
 		subs->cur_rate = rate;

sound/usb/pcm.h

@@ -3,11 +3,11 @@
 
 void snd_usb_set_pcm_ops(struct snd_pcm *pcm, int stream);
 
-int snd_usb_init_pitch(struct usb_device *dev, int iface,
+int snd_usb_init_pitch(struct snd_usb_audio *chip, int iface,
 		       struct usb_host_interface *alts,
 		       struct audioformat *fmt);
 
-int snd_usb_init_sample_rate(struct usb_device *dev, int iface,
+int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
 			     struct usb_host_interface *alts,
 			     struct audioformat *fmt, int rate);
 

sound/usb/quirks.c

@@ -159,8 +159,8 @@ static int create_fixed_stream_quirk(struct snd_usb_audio *chip,
 	fp->datainterval = snd_usb_parse_datainterval(chip, alts);
 	fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
 	usb_set_interface(chip->dev, fp->iface, 0);
-	snd_usb_init_pitch(chip->dev, fp->iface, alts, fp);
-	snd_usb_init_sample_rate(chip->dev, fp->iface, alts, fp, fp->rate_max);
+	snd_usb_init_pitch(chip, fp->iface, alts, fp);
+	snd_usb_init_sample_rate(chip, fp->iface, alts, fp, fp->rate_max);
 	return 0;
 }