1 files changed, 493 insertions, 0 deletions

diff --git a/sound/usb/implicit.c b/sound/usb/implicit.c
new file mode 100644
index 000000000..4727043fd
--- /dev/null
+++ b/sound/usb/implicit.c
@@ -0,0 +1,493 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+//
+// Special handling for implicit feedback mode
+//
+
+#include <linux/init.h>
+#include <linux/usb.h>
+#include <linux/usb/audio.h>
+#include <linux/usb/audio-v2.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+
+#include "usbaudio.h"
+#include "card.h"
+#include "helper.h"
+#include "pcm.h"
+#include "implicit.h"
+
+enum {
+	IMPLICIT_FB_NONE,
+	IMPLICIT_FB_GENERIC,
+	IMPLICIT_FB_FIXED,
+	IMPLICIT_FB_BOTH,	/* generic playback + capture (for BOSS) */
+};
+
+struct snd_usb_implicit_fb_match {
+	unsigned int id;
+	unsigned int iface_class;
+	unsigned int ep_num;
+	unsigned int iface;
+	int type;
+};
+
+#define IMPLICIT_FB_GENERIC_DEV(vend, prod) \
+	{ .id = USB_ID(vend, prod), .type = IMPLICIT_FB_GENERIC }
+#define IMPLICIT_FB_FIXED_DEV(vend, prod, ep, ifnum) \
+	{ .id = USB_ID(vend, prod), .type = IMPLICIT_FB_FIXED, .ep_num = (ep),\
+	    .iface = (ifnum) }
+#define IMPLICIT_FB_BOTH_DEV(vend, prod, ep, ifnum) \
+	{ .id = USB_ID(vend, prod), .type = IMPLICIT_FB_BOTH, .ep_num = (ep),\
+	    .iface = (ifnum) }
+#define IMPLICIT_FB_SKIP_DEV(vend, prod) \
+	{ .id = USB_ID(vend, prod), .type = IMPLICIT_FB_NONE }
+
+/* Implicit feedback quirk table for playback */
+static const struct snd_usb_implicit_fb_match playback_implicit_fb_quirks[] = {
+	/* Fixed EP */
+	/* FIXME: check the availability of generic matching */
+	IMPLICIT_FB_FIXED_DEV(0x0763, 0x2030, 0x81, 3), /* M-Audio Fast Track C400 */
+	IMPLICIT_FB_FIXED_DEV(0x0763, 0x2031, 0x81, 3), /* M-Audio Fast Track C600 */
+	IMPLICIT_FB_FIXED_DEV(0x0763, 0x2080, 0x81, 2), /* M-Audio FastTrack Ultra */
+	IMPLICIT_FB_FIXED_DEV(0x0763, 0x2081, 0x81, 2), /* M-Audio FastTrack Ultra */
+	IMPLICIT_FB_FIXED_DEV(0x2466, 0x8010, 0x81, 2), /* Fractal Audio Axe-Fx III */
+	IMPLICIT_FB_FIXED_DEV(0x31e9, 0x0001, 0x81, 2), /* Solid State Logic SSL2 */
+	IMPLICIT_FB_FIXED_DEV(0x31e9, 0x0002, 0x81, 2), /* Solid State Logic SSL2+ */
+	IMPLICIT_FB_FIXED_DEV(0x0499, 0x172f, 0x81, 2), /* Steinberg UR22C */
+	IMPLICIT_FB_FIXED_DEV(0x0d9a, 0x00df, 0x81, 2), /* RTX6001 */
+	IMPLICIT_FB_FIXED_DEV(0x22f0, 0x0006, 0x81, 3), /* Allen&Heath Qu-16 */
+	IMPLICIT_FB_FIXED_DEV(0x1686, 0xf029, 0x82, 2), /* Zoom UAC-2 */
+	IMPLICIT_FB_FIXED_DEV(0x2466, 0x8003, 0x86, 2), /* Fractal Audio Axe-Fx II */
+	IMPLICIT_FB_FIXED_DEV(0x0499, 0x172a, 0x86, 2), /* Yamaha MODX */
+
+	/* Special matching */
+	{ .id = USB_ID(0x07fd, 0x0004), .iface_class = USB_CLASS_AUDIO,
+	  .type = IMPLICIT_FB_NONE },		/* MicroBook IIc */
+	/* ep = 0x84, ifnum = 0 */
+	{ .id = USB_ID(0x07fd, 0x0004), .iface_class = USB_CLASS_VENDOR_SPEC,
+	  .type = IMPLICIT_FB_FIXED,
+	  .ep_num = 0x84, .iface = 0 },		/* MOTU MicroBook II */
+
+	{} /* terminator */
+};
+
+/* Implicit feedback quirk table for capture: only FIXED type */
+static const struct snd_usb_implicit_fb_match capture_implicit_fb_quirks[] = {
+	{} /* terminator */
+};
+
+/* set up sync EP information on the audioformat */
+static int add_implicit_fb_sync_ep(struct snd_usb_audio *chip,
+				   struct audioformat *fmt,
+				   int ep, int ep_idx, int ifnum,
+				   const struct usb_host_interface *alts)
+{
+	struct usb_interface *iface;
+
+	if (!alts) {
+		iface = usb_ifnum_to_if(chip->dev, ifnum);
+		if (!iface || iface->num_altsetting < 2)
+			return 0;
+		alts = &iface->altsetting[1];
+	}
+
+	fmt->sync_ep = ep;
+	fmt->sync_iface = ifnum;
+	fmt->sync_altsetting = alts->desc.bAlternateSetting;
+	fmt->sync_ep_idx = ep_idx;
+	fmt->implicit_fb = 1;
+	usb_audio_dbg(chip,
+		      "%d:%d: added %s implicit_fb sync_ep %x, iface %d:%d\n",
+		      fmt->iface, fmt->altsetting,
+		      (ep & USB_DIR_IN) ? "playback" : "capture",
+		      fmt->sync_ep, fmt->sync_iface, fmt->sync_altsetting);
+	return 1;
+}
+
+/* Check whether the given UAC2 iface:altset points to an implicit fb source */
+static int add_generic_uac2_implicit_fb(struct snd_usb_audio *chip,
+					struct audioformat *fmt,
+					unsigned int ifnum,
+					unsigned int altsetting)
+{
+	struct usb_host_interface *alts;
+	struct usb_endpoint_descriptor *epd;
+
+	alts = snd_usb_get_host_interface(chip, ifnum, altsetting);
+	if (!alts)
+		return 0;
+	if (alts->desc.bInterfaceClass != USB_CLASS_AUDIO ||
+	    alts->desc.bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING ||
+	    alts->desc.bInterfaceProtocol != UAC_VERSION_2 ||
+	    alts->desc.bNumEndpoints < 1)
+		return 0;
+	epd = get_endpoint(alts, 0);
+	if (!usb_endpoint_is_isoc_in(epd) ||
+	    (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
+					USB_ENDPOINT_USAGE_IMPLICIT_FB)
+		return 0;
+	return add_implicit_fb_sync_ep(chip, fmt, epd->bEndpointAddress, 0,
+				       ifnum, alts);
+}
+
+static bool roland_sanity_check_iface(struct usb_host_interface *alts)
+{
+	if (alts->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC ||
+	    (alts->desc.bInterfaceSubClass != 2 &&
+	     alts->desc.bInterfaceProtocol != 2) ||
+	    alts->desc.bNumEndpoints < 1)
+		return false;
+	return true;
+}
+
+/* Like the UAC2 case above, but specific to Roland with vendor class and hack */
+static int add_roland_implicit_fb(struct snd_usb_audio *chip,
+				  struct audioformat *fmt,
+				  struct usb_host_interface *alts)
+{
+	struct usb_endpoint_descriptor *epd;
+
+	if (!roland_sanity_check_iface(alts))
+		return 0;
+	/* only when both streams are with ASYNC type */
+	epd = get_endpoint(alts, 0);
+	if (!usb_endpoint_is_isoc_out(epd) ||
+	    (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
+		return 0;
+
+	/* check capture EP */
+	alts = snd_usb_get_host_interface(chip,
+					  alts->desc.bInterfaceNumber + 1,
+					  alts->desc.bAlternateSetting);
+	if (!alts || !roland_sanity_check_iface(alts))
+		return 0;
+	epd = get_endpoint(alts, 0);
+	if (!usb_endpoint_is_isoc_in(epd) ||
+	    (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
+		return 0;
+	chip->quirk_flags |= QUIRK_FLAG_PLAYBACK_FIRST;
+	return add_implicit_fb_sync_ep(chip, fmt, epd->bEndpointAddress, 0,
+				       alts->desc.bInterfaceNumber, alts);
+}
+
+/* capture quirk for Roland device; always full-duplex */
+static int add_roland_capture_quirk(struct snd_usb_audio *chip,
+				    struct audioformat *fmt,
+				    struct usb_host_interface *alts)
+{
+	struct usb_endpoint_descriptor *epd;
+
+	if (!roland_sanity_check_iface(alts))
+		return 0;
+	epd = get_endpoint(alts, 0);
+	if (!usb_endpoint_is_isoc_in(epd) ||
+	    (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
+		return 0;
+
+	alts = snd_usb_get_host_interface(chip,
+					  alts->desc.bInterfaceNumber - 1,
+					  alts->desc.bAlternateSetting);
+	if (!alts || !roland_sanity_check_iface(alts))
+		return 0;
+	epd = get_endpoint(alts, 0);
+	if (!usb_endpoint_is_isoc_out(epd))
+		return 0;
+	return add_implicit_fb_sync_ep(chip, fmt, epd->bEndpointAddress, 0,
+				       alts->desc.bInterfaceNumber, alts);
+}
+
+/* Playback and capture EPs on Pioneer devices share the same iface/altset
+ * for the implicit feedback operation
+ */
+static bool is_pioneer_implicit_fb(struct snd_usb_audio *chip,
+				   struct usb_host_interface *alts)
+
+{
+	struct usb_endpoint_descriptor *epd;
+
+	if (USB_ID_VENDOR(chip->usb_id) != 0x2b73 &&
+	    USB_ID_VENDOR(chip->usb_id) != 0x08e4)
+		return false;
+	if (alts->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC)
+		return false;
+	if (alts->desc.bNumEndpoints != 2)
+		return false;
+
+	epd = get_endpoint(alts, 0);
+	if (!usb_endpoint_is_isoc_out(epd) ||
+	    (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
+		return false;
+
+	epd = get_endpoint(alts, 1);
+	if (!usb_endpoint_is_isoc_in(epd) ||
+	    (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC ||
+	    ((epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
+	     USB_ENDPOINT_USAGE_DATA &&
+	     (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
+	     USB_ENDPOINT_USAGE_IMPLICIT_FB))
+		return false;
+
+	return true;
+}
+
+static int __add_generic_implicit_fb(struct snd_usb_audio *chip,
+				     struct audioformat *fmt,
+				     int iface, int altset)
+{
+	struct usb_host_interface *alts;
+	struct usb_endpoint_descriptor *epd;
+
+	alts = snd_usb_get_host_interface(chip, iface, altset);
+	if (!alts)
+		return 0;
+
+	if ((alts->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC &&
+	     alts->desc.bInterfaceClass != USB_CLASS_AUDIO) ||
+	    alts->desc.bNumEndpoints < 1)
+		return 0;
+	epd = get_endpoint(alts, 0);
+	if (!usb_endpoint_is_isoc_in(epd) ||
+	    (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
+		return 0;
+	return add_implicit_fb_sync_ep(chip, fmt, epd->bEndpointAddress, 0,
+				       iface, alts);
+}
+
+/* More generic quirk: look for the sync EP next to the data EP */
+static int add_generic_implicit_fb(struct snd_usb_audio *chip,
+				   struct audioformat *fmt,
+				   struct usb_host_interface *alts)
+{
+	if ((fmt->ep_attr & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
+		return 0;
+
+	if (__add_generic_implicit_fb(chip, fmt,
+				      alts->desc.bInterfaceNumber + 1,
+				      alts->desc.bAlternateSetting))
+		return 1;
+	return __add_generic_implicit_fb(chip, fmt,
+					 alts->desc.bInterfaceNumber - 1,
+					 alts->desc.bAlternateSetting);
+}
+
+static const struct snd_usb_implicit_fb_match *
+find_implicit_fb_entry(struct snd_usb_audio *chip,
+		       const struct snd_usb_implicit_fb_match *match,
+		       const struct usb_host_interface *alts)
+{
+	for (; match->id; match++)
+		if (match->id == chip->usb_id &&
+		    (!match->iface_class ||
+		     (alts->desc.bInterfaceClass == match->iface_class)))
+			return match;
+
+	return NULL;
+}
+
+/* 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)
+{
+	const struct snd_usb_implicit_fb_match *p;
+	unsigned int attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
+
+	p = find_implicit_fb_entry(chip, playback_implicit_fb_quirks, alts);
+	if (p) {
+		switch (p->type) {
+		case IMPLICIT_FB_GENERIC:
+			return add_generic_implicit_fb(chip, fmt, alts);
+		case IMPLICIT_FB_NONE:
+			return 0; /* No quirk */
+		case IMPLICIT_FB_FIXED:
+			return add_implicit_fb_sync_ep(chip, fmt, p->ep_num, 0,
+						       p->iface, NULL);
+		}
+	}
+
+	/* Special handling for devices with capture quirks */
+	p = find_implicit_fb_entry(chip, capture_implicit_fb_quirks, alts);
+	if (p) {
+		switch (p->type) {
+		case IMPLICIT_FB_FIXED:
+			return 0; /* no quirk */
+		case IMPLICIT_FB_BOTH:
+			chip->quirk_flags |= QUIRK_FLAG_PLAYBACK_FIRST;
+			return add_generic_implicit_fb(chip, fmt, alts);
+		}
+	}
+
+	/* Generic UAC2 implicit feedback */
+	if (attr == USB_ENDPOINT_SYNC_ASYNC &&
+	    alts->desc.bInterfaceClass == USB_CLASS_AUDIO &&
+	    alts->desc.bInterfaceProtocol == UAC_VERSION_2 &&
+	    alts->desc.bNumEndpoints == 1) {
+		if (add_generic_uac2_implicit_fb(chip, fmt,
+						 alts->desc.bInterfaceNumber + 1,
+						 alts->desc.bAlternateSetting))
+			return 1;
+	}
+
+	/* Roland/BOSS implicit feedback with vendor spec class */
+	if (USB_ID_VENDOR(chip->usb_id) == 0x0582) {
+		if (add_roland_implicit_fb(chip, fmt, alts) > 0)
+			return 1;
+	}
+
+	/* Pioneer devices with vendor spec class */
+	if (is_pioneer_implicit_fb(chip, alts)) {
+		chip->quirk_flags |= QUIRK_FLAG_PLAYBACK_FIRST;
+		return add_implicit_fb_sync_ep(chip, fmt,
+					       get_endpoint(alts, 1)->bEndpointAddress,
+					       1, alts->desc.bInterfaceNumber,
+					       alts);
+	}
+
+	/* Try the generic implicit fb if available */
+	if (chip->generic_implicit_fb ||
+	    (chip->quirk_flags & QUIRK_FLAG_GENERIC_IMPLICIT_FB))
+		return add_generic_implicit_fb(chip, fmt, alts);
+
+	/* No quirk */
+	return 0;
+}
+
+/* same for capture, but only handling FIXED entry */
+static int audioformat_capture_quirk(struct snd_usb_audio *chip,
+				     struct audioformat *fmt,
+				     struct usb_host_interface *alts)
+{
+	const struct snd_usb_implicit_fb_match *p;
+
+	p = find_implicit_fb_entry(chip, capture_implicit_fb_quirks, alts);
+	if (p && (p->type == IMPLICIT_FB_FIXED || p->type == IMPLICIT_FB_BOTH))
+		return add_implicit_fb_sync_ep(chip, fmt, p->ep_num, 0,
+					       p->iface, NULL);
+
+	/* Roland/BOSS need full-duplex streams */
+	if (USB_ID_VENDOR(chip->usb_id) == 0x0582) {
+		if (add_roland_capture_quirk(chip, fmt, alts) > 0)
+			return 1;
+	}
+
+	if (is_pioneer_implicit_fb(chip, alts))
+		return 1; /* skip the quirk, also don't handle generic sync EP */
+	return 0;
+}
+
+/*
+ * Parse altset and set up implicit feedback endpoint on the audioformat
+ */
+int snd_usb_parse_implicit_fb_quirk(struct snd_usb_audio *chip,
+				    struct audioformat *fmt,
+				    struct usb_host_interface *alts)
+{
+	if (chip->quirk_flags & QUIRK_FLAG_SKIP_IMPLICIT_FB)
+		return 0;
+	if (fmt->endpoint & USB_DIR_IN)
+		return audioformat_capture_quirk(chip, fmt, alts);
+	else
+		return audioformat_implicit_fb_quirk(chip, fmt, alts);
+}
+
+/*
+ * 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 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;
+}
+
+/*
+ * Return the audioformat that is suitable for the implicit fb
+ */
+const struct audioformat *
+snd_usb_find_implicit_fb_sync_format(struct snd_usb_audio *chip,
+				     const struct audioformat *target,
+				     const struct snd_pcm_hw_params *params,
+				     int stream,
+				     bool *fixed_rate)
+{
+	struct snd_usb_substream *subs;
+	const struct audioformat *fp, *sync_fmt = NULL;
+	int score, high_score;
+
+	/* Use the original audioformat as fallback for the shared altset */
+	if (target->iface == target->sync_iface &&
+	    target->altsetting == target->sync_altsetting)
+		sync_fmt = target;
+
+	subs = find_matching_substream(chip, stream, target->sync_ep,
+				       target->fmt_type);
+	if (!subs)
+		goto end;
+
+	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;
+		}
+	}
+
+ end:
+	if (fixed_rate)
+		*fixed_rate = snd_usb_pcm_has_fixed_rate(subs);
+	return sync_fmt;
+}
+