ALSA: usb-audio: Factor out the implicit feedback quirk code

The code dealing with the implicit feedback mode grew recently, and
it's becoming messy.  As we receive more and more devices that need
the similar handling, it's better to be processed through a table
instead of the open code.

This patch moves the code that is relevant with parsing the implicit
feedback mode and some helpers into another file, implicit.c.  The
detection and the setup of the implicit feedback sync EPs are
rewritten to use the ID/class matching table instead.

There should be no functional changes.

Tested-by: Keith Milner <kamilner@superlative.org>
Tested-by: Dylan Robinson <dylan_robinson@motu.com>
Link: https://lore.kernel.org/r/20201123085347.19667-38-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 14 insertions, 306 deletions

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 676acc20595b..56079901769f 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -23,6 +23,7 @@
 #include "clock.h"
 #include "power.h"
 #include "media.h"
+#include "implicit.h"
 
 #define SUBSTREAM_FLAG_DATA_EP_STARTED	0
 #define SUBSTREAM_FLAG_SYNC_EP_STARTED	1
@@ -276,211 +277,7 @@ static int snd_usb_pcm_sync_stop(struct snd_pcm_substream *substream)
 	return 0;
 }
 
-/* Check whether the given iface:altsetting points to an implicit fb source */
-static bool search_generic_implicit_fb(struct snd_usb_audio *chip, int ifnum,
-				       unsigned int altsetting,
-				       struct usb_host_interface **altsp,
-				       unsigned int *ep)
-{
-	struct usb_host_interface *alts;
-	struct usb_interface_descriptor *altsd;
-	struct usb_endpoint_descriptor *epd;
-
-	alts = snd_usb_get_host_interface(chip, ifnum, altsetting);
-	if (!alts)
-		return false;
-	altsd = get_iface_desc(alts);
-	if (altsd->bInterfaceClass != USB_CLASS_AUDIO ||
-	    altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING ||
-	    altsd->bInterfaceProtocol != UAC_VERSION_2 ||
-	    altsd->bNumEndpoints < 1)
-		return false;
-	epd = get_endpoint(alts, 0);
-	if (!usb_endpoint_is_isoc_in(epd) ||
-	    (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
-					USB_ENDPOINT_USAGE_IMPLICIT_FB)
-		return false;
-	*ep = epd->bEndpointAddress;
-	*altsp = alts;
-	return true;
-}
-
-/* Like the function above, but specific to Roland with vendor class and hack */
-static bool search_roland_implicit_fb(struct snd_usb_audio *chip, int ifnum,
-				      unsigned int altsetting,
-				      struct usb_host_interface **altsp,
-				      unsigned int *ep)
-{
-	struct usb_host_interface *alts;
-	struct usb_interface_descriptor *altsd;
-	struct usb_endpoint_descriptor *epd;
-
-	alts = snd_usb_get_host_interface(chip, ifnum, altsetting);
-	if (!alts)
-		return false;
-	altsd = get_iface_desc(alts);
-	if (altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC ||
-	    (altsd->bInterfaceSubClass != 2 &&
-	     altsd->bInterfaceProtocol != 2) ||
-	    altsd->bNumEndpoints < 1)
-		return false;
-	epd = get_endpoint(alts, 0);
-	if (!usb_endpoint_is_isoc_in(epd) ||
-	    (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
-					USB_ENDPOINT_USAGE_IMPLICIT_FB)
-		return false;
-	*ep = epd->bEndpointAddress;
-	*altsp = alts;
-	return true;
-}
-
-/* Setup an implicit feedback endpoint from a quirk. Returns 0 if no quirk
- * applies. Returns 1 if a quirk was found.
- */
-static int audioformat_implicit_fb_quirk(struct snd_usb_audio *chip,
-					 struct audioformat *fmt,
-					 struct usb_host_interface *alts)
-{
-	struct usb_device *dev = chip->dev;
-	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
-	struct usb_interface *iface;
-	unsigned int attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
-	unsigned int ep;
-	unsigned int ifnum;
-
-	switch (chip->usb_id) {
-	case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
-	case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
-	case USB_ID(0x22f0, 0x0006): /* Allen&Heath Qu-16 */
-		ep = 0x81;
-		ifnum = 3;
-		goto add_sync_ep_from_ifnum;
-	case USB_ID(0x0763, 0x2080): /* M-Audio FastTrack Ultra */
-	case USB_ID(0x0763, 0x2081):
-		ep = 0x81;
-		ifnum = 2;
-		goto add_sync_ep_from_ifnum;
-	case USB_ID(0x2466, 0x8003): /* Fractal Audio Axe-Fx II */
-	case USB_ID(0x0499, 0x172a): /* Yamaha MODX */
-		ep = 0x86;
-		ifnum = 2;
-		goto add_sync_ep_from_ifnum;
-	case USB_ID(0x2466, 0x8010): /* Fractal Audio Axe-Fx III */
-		ep = 0x81;
-		ifnum = 2;
-		goto add_sync_ep_from_ifnum;
-	case USB_ID(0x1686, 0xf029): /* Zoom UAC-2 */
-		ep = 0x82;
-		ifnum = 2;
-		goto add_sync_ep_from_ifnum;
-	case USB_ID(0x1397, 0x0001): /* Behringer UFX1604 */
-	case USB_ID(0x1397, 0x0002): /* Behringer UFX1204 */
-		ep = 0x81;
-		ifnum = 1;
-		goto add_sync_ep_from_ifnum;
-	case USB_ID(0x07fd, 0x0004): /* MOTU MicroBook II/IIc */
-		/* MicroBook IIc */
-		if (altsd->bInterfaceClass == USB_CLASS_AUDIO)
-			return 0;
-
-		/* MicroBook II */
-		ep = 0x84;
-		ifnum = 0;
-		goto add_sync_ep_from_ifnum;
-	case USB_ID(0x07fd, 0x0008): /* MOTU M Series */
-	case USB_ID(0x31e9, 0x0001): /* Solid State Logic SSL2 */
-	case USB_ID(0x31e9, 0x0002): /* Solid State Logic SSL2+ */
-	case USB_ID(0x0499, 0x172f): /* Steinberg UR22C */
-	case USB_ID(0x0d9a, 0x00df): /* RTX6001 */
-		ep = 0x81;
-		ifnum = 2;
-		goto add_sync_ep_from_ifnum;
-	case USB_ID(0x2b73, 0x000a): /* Pioneer DJ DJM-900NXS2 */
-	case USB_ID(0x2b73, 0x0017): /* Pioneer DJ DJM-250MK2 */
-		ep = 0x82;
-		ifnum = 0;
-		goto add_sync_ep_from_ifnum;
-	case USB_ID(0x0582, 0x01d8): /* BOSS Katana */
-		/* BOSS Katana amplifiers do not need quirks */
-		return 0;
-	case USB_ID(0x0582, 0x01e5): /* BOSS GT-001 */
-		/* BOSS GT-001 needs no implicit fb for playback */
-		return 0;
-	}
-
-	/* Generic UAC2 implicit feedback */
-	if (attr == USB_ENDPOINT_SYNC_ASYNC &&
-	    altsd->bInterfaceClass == USB_CLASS_AUDIO &&
-	    altsd->bInterfaceProtocol == UAC_VERSION_2 &&
-	    altsd->bNumEndpoints == 1) {
-		ifnum = altsd->bInterfaceNumber + 1;
-		if (search_generic_implicit_fb(chip, ifnum,
-					       altsd->bAlternateSetting,
-					       &alts, &ep))
-			goto add_sync_ep;
-	}
-
-	/* Roland/BOSS implicit feedback with vendor spec class */
-	if (attr == USB_ENDPOINT_SYNC_ASYNC &&
-	    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
-	    altsd->bInterfaceProtocol == 2 &&
-	    altsd->bNumEndpoints == 1 &&
-	    USB_ID_VENDOR(chip->usb_id) == 0x0582 /* Roland */) {
-		ifnum = altsd->bInterfaceNumber + 1;
-		if (search_roland_implicit_fb(chip, ifnum,
-					      altsd->bAlternateSetting,
-					      &alts, &ep))
-			goto add_sync_ep;
-	}
-
-	/* No quirk */
-	return 0;
-
-add_sync_ep_from_ifnum:
-	iface = usb_ifnum_to_if(dev, ifnum);
-
-	if (!iface || iface->num_altsetting < 2)
-		return 0;
-
-	alts = &iface->altsetting[1];
-
-add_sync_ep:
-	fmt->sync_ep = ep;
-	fmt->sync_iface = ifnum;
-	fmt->sync_altsetting = alts->desc.bAlternateSetting;
-	fmt->sync_ep_idx = 0;
-	fmt->implicit_fb = 1;
-	dev_dbg(&dev->dev, "%d:%d: found implicit_fb sync_ep=%x, iface=%d, alt=%d\n",
-		fmt->iface, fmt->altsetting, fmt->sync_ep, fmt->sync_iface,
-		fmt->sync_altsetting);
-
-	return 1;
-}
-
-static int audioformat_capture_quirk(struct snd_usb_audio *chip,
-				     struct audioformat *fmt,
-				     struct usb_host_interface *alts)
-{
-	struct usb_device *dev = chip->dev;
-
-	switch (chip->usb_id) {
-	case USB_ID(0x0582, 0x01e5): /* BOSS GT-001 */
-		if (!snd_usb_get_host_interface(chip, 0x01, 0x01))
-			return 0;
-		fmt->sync_ep = 0x0d;
-		fmt->sync_iface = 0x01;
-		fmt->sync_altsetting = 0x01;
-		fmt->sync_ep_idx = 0;
-		fmt->implicit_fb = 1;
-		dev_dbg(&dev->dev, "%d:%d: added fake capture sync sync_ep=%x, iface=%d, alt=%d\n",
-			fmt->iface, fmt->altsetting, fmt->sync_ep, fmt->sync_iface,
-			fmt->sync_altsetting);
-		return 1;
-	}
-	return 0;
-
-}
-
+/* Set up sync endpoint */
 int snd_usb_audioformat_set_sync_ep(struct snd_usb_audio *chip,
 				    struct audioformat *fmt)
 {
@@ -496,20 +293,18 @@ int snd_usb_audioformat_set_sync_ep(struct snd_usb_audio *chip,
 		return 0;
 	altsd = get_iface_desc(alts);
 
-	is_playback = !(get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN);
-	if (is_playback) {
-		err = audioformat_implicit_fb_quirk(chip, fmt, alts);
-		if (err > 0)
-			return 0;
-	} else {
-		err = audioformat_capture_quirk(chip, fmt, alts);
-		if (err > 0)
-			return 0;
-	}
+	err = snd_usb_parse_implicit_fb_quirk(chip, fmt, alts);
+	if (err > 0)
+		return 0; /* matched */
+
+	/*
+	 * Generic sync EP handling
+	 */
 
 	if (altsd->bNumEndpoints < 2)
 		return 0;
 
+	is_playback = !(get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN);
 	attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
 	if ((is_playback && (attr == USB_ENDPOINT_SYNC_SYNC ||
 			     attr == USB_ENDPOINT_SYNC_ADAPTIVE)) ||
@@ -569,45 +364,6 @@ int snd_usb_audioformat_set_sync_ep(struct snd_usb_audio *chip,
 	return 0;
 }
 
-/*
- * Return the score of matching two audioformats.
- * Veto the audioformat if:
- * - It has no channels for some reason.
- * - Requested PCM format is not supported.
- * - Requested sample rate is not supported.
- */
-static int match_endpoint_audioformats(struct snd_usb_substream *subs,
-				       const struct audioformat *fp,
-				       int rate, int channels,
-				       snd_pcm_format_t pcm_format)
-{
-	int i, score;
-
-	if (fp->channels < 1)
-		return 0;
-
-	if (!(fp->formats & pcm_format_to_bits(pcm_format)))
-		return 0;
-
-	if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS) {
-		if (rate < fp->rate_min || rate > fp->rate_max)
-			return 0;
-	} else {
-		for (i = 0; i < fp->nr_rates; i++) {
-			if (fp->rate_table[i] == rate)
-				break;
-		}
-		if (i >= fp->nr_rates)
-			return 0;
-	}
-
-	score = 1;
-	if (fp->channels == channels)
-		score++;
-
-	return score;
-}
-
 static int snd_usb_pcm_change_state(struct snd_usb_substream *subs, int state)
 {
 	int ret;
@@ -656,53 +412,6 @@ int snd_usb_pcm_resume(struct snd_usb_stream *as)
 	return 0;
 }
 
-static struct snd_usb_substream *
-find_matching_substream(struct snd_usb_audio *chip, int stream, int ep_num,
-			int fmt_type)
-{
-	struct snd_usb_stream *as;
-	struct snd_usb_substream *subs;
-
-	list_for_each_entry(as, &chip->pcm_list, list) {
-		subs = &as->substream[stream];
-		if (as->fmt_type == fmt_type && subs->ep_num == ep_num)
-			return subs;
-	}
-
-	return NULL;
-}
-
-static const struct audioformat *
-find_implicit_fb_sync_format(struct snd_usb_audio *chip,
-			     const struct audioformat *target,
-			     const struct snd_pcm_hw_params *params,
-			     int stream)
-{
-	struct snd_usb_substream *subs;
-	const struct audioformat *fp, *sync_fmt;
-	int score, high_score;
-
-	subs = find_matching_substream(chip, stream, target->sync_ep,
-				       target->fmt_type);
-	if (!subs)
-		return NULL;
-
-	sync_fmt = NULL;
-	high_score = 0;
-	list_for_each_entry(fp, &subs->fmt_list, list) {
-		score = match_endpoint_audioformats(subs, fp,
-						    params_rate(params),
-						    params_channels(params),
-						    params_format(params));
-		if (score > high_score) {
-			sync_fmt = fp;
-			high_score = score;
-		}
-	}
-
-	return sync_fmt;
-}
-
 static void close_endpoints(struct snd_usb_audio *chip,
 			    struct snd_usb_substream *subs)
 {
@@ -775,11 +484,10 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 		goto stop_pipeline;
 	}
 
-	if (fmt->implicit_fb &&
-	    (fmt->iface != fmt->sync_iface ||
-	     fmt->altsetting != fmt->sync_altsetting)) {
-		sync_fmt = find_implicit_fb_sync_format(chip, fmt, hw_params,
-							!substream->stream);
+	if (fmt->implicit_fb) {
+		sync_fmt = snd_usb_find_implicit_fb_sync_format(chip, fmt,
+								hw_params,
+								!substream->stream);
 		if (!sync_fmt) {
 			usb_audio_dbg(chip,
 				      "cannot find sync format: ep=0x%x, iface=%d:%d, format=%s, rate=%d, channels=%d\n",