[ALSA] usb-audio - high speed audio support

USB generic driver
Add support for endpoints with bInterval > 1, and decoding of the
wMaxPacketSize field of high-speed endpoints.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

1 files changed, 25 insertions, 12 deletions

diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index b5e734d975e..facd9fc11c3 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -153,6 +153,7 @@ struct snd_usb_substream {
         unsigned int format;     /* USB data format */
         unsigned int datapipe;   /* the data i/o pipe */
         unsigned int syncpipe;   /* 1 - async out or adaptive in */
+        unsigned int datainterval;      /* log_2 of data packet interval */
         unsigned int syncinterval;  /* P for adaptive mode, 0 otherwise */
         unsigned int freqn;      /* nominal sampling rate in fs/fps in Q16.16 format */
         unsigned int freqm;      /* momentary sampling rate in fs/fps in Q16.16 format */
@@ -518,7 +519,8 @@ static int prepare_playback_urb(snd_usb_substream_t *subs,
                 if (subs->fill_max)
                         counts = subs->maxframesize; /* fixed */
                 else {
-                        subs->phase = (subs->phase & 0xffff) + subs->freqm;
+                        subs->phase = (subs->phase & 0xffff)
+                                + (subs->freqm << subs->datainterval);
                         counts = subs->phase >> 16;
                         if (counts > subs->maxframesize)
                                 counts = subs->maxframesize;
@@ -899,16 +901,19 @@ static int init_substream_urbs(snd_usb_substream_t *subs, unsigned int period_by
         else
                 subs->freqn = get_usb_high_speed_rate(rate);
         subs->freqm = subs->freqn;
-        subs->freqmax = subs->freqn + (subs->freqn >> 2); /* max. allowed frequency */
-        subs->phase = 0;
-
-        /* calculate the max. size of packet */
-        maxsize = ((subs->freqmax + 0xffff) * (frame_bits >> 3)) >> 16;
-        if (subs->maxpacksize && maxsize > subs->maxpacksize) {
-                //snd_printd(KERN_DEBUG "maxsize %d is greater than defined size %d\n",
-                //         maxsize, subs->maxpacksize);
+        /* calculate max. frequency */
+        if (subs->maxpacksize) {
+                /* whatever fits into a max. size packet */
                 maxsize = subs->maxpacksize;
+                subs->freqmax = (maxsize / (frame_bits >> 3))
+                                << (16 - subs->datainterval);
+        } else {
+                /* no max. packet size: just take 25% higher than nominal */
+                subs->freqmax = subs->freqn + (subs->freqn >> 2);
+                maxsize = ((subs->freqmax + 0xffff) * (frame_bits >> 3))
+                                >> (16 - subs->datainterval);
         }
+        subs->phase = 0;
 
         if (subs->fill_max)
                 subs->curpacksize = subs->maxpacksize;
@@ -918,7 +923,7 @@ static int init_substream_urbs(snd_usb_substream_t *subs, unsigned int period_by
         if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
                 urb_packs = nrpacks;
         else
-                urb_packs = nrpacks * 8;
+                urb_packs = (nrpacks * 8) >> subs->datainterval;
 
         /* allocate a temporary buffer for playback */
         if (is_playback) {
@@ -991,7 +996,7 @@ static int init_substream_urbs(snd_usb_substream_t *subs, unsigned int period_by
                 u->urb->pipe = subs->datapipe;
                 u->urb->transfer_flags = URB_ISO_ASAP;
                 u->urb->number_of_packets = u->packets;
-                u->urb->interval = 1;
+                u->urb->interval = 1 << subs->datainterval;
                 u->urb->context = u;
                 u->urb->complete = snd_usb_complete_callback(snd_complete_urb);
         }
@@ -1195,6 +1200,12 @@ static int set_format(snd_usb_substream_t *subs, struct audioformat *fmt)
                 subs->datapipe = usb_sndisocpipe(dev, ep);
         else
                 subs->datapipe = usb_rcvisocpipe(dev, ep);
+        if (snd_usb_get_speed(subs->dev) == USB_SPEED_HIGH &&
+            get_endpoint(alts, 0)->bInterval >= 1 &&
+            get_endpoint(alts, 0)->bInterval <= 4)
+                subs->datainterval = get_endpoint(alts, 0)->bInterval - 1;
+        else
+                subs->datainterval = 0;
         subs->syncpipe = subs->syncinterval = 0;
         subs->maxpacksize = fmt->maxpacksize;
         subs->fill_max = 0;
@@ -2492,8 +2503,10 @@ static int parse_audio_endpoints(snd_usb_audio_t *chip, int iface_no)
                 fp->altset_idx = i;
                 fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
                 fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
-                /* FIXME: decode wMaxPacketSize of high bandwith endpoints */
                 fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
+                if (snd_usb_get_speed(dev) == USB_SPEED_HIGH)
+                        fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
+                                        * (fp->maxpacksize & 0x7ff);
                 fp->attributes = csep[3];
 
                 /* some quirks for attributes here */