ALSA: sound/usb: add preliminary support for UAC2 interrupts

For both UAC1 and UAC2, interrupt endpoint messages are now parsed with
structs rather that with anonymous buffer array accesses.

For UAC2, only CUR interrupt notifications are supported for now.

snd_usb_mixer_status_complete() was renamed to
snd_usb_mixer_interrupt().

Fixed one indentation flaw on the way.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 85 insertions, 13 deletions

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index e350f053440a..820dfe08ac22 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -1443,8 +1443,8 @@ static struct procunit_info procunits[] = {
  * predefined data for extension units
  */
 static struct procunit_value_info clock_rate_xu_info[] = {
-       { USB_XU_CLOCK_RATE_SELECTOR, "Selector", USB_MIXER_U8, 0 },
-       { 0 }
+        { USB_XU_CLOCK_RATE_SELECTOR, "Selector", USB_MIXER_U8, 0 },
+        { 0 }
 };
 static struct procunit_value_info clock_source_xu_info[] = {
         { USB_XU_CLOCK_SOURCE_SELECTOR, "External", USB_MIXER_BOOLEAN },
@@ -1967,26 +1967,98 @@ static void snd_usb_mixer_proc_read(struct snd_info_entry *entry,
         }
 }
 
-static void snd_usb_mixer_status_complete(struct urb *urb)
+static void snd_usb_mixer_interrupt_v2(struct usb_mixer_interface *mixer,
+                                       int attribute, int value, int index)
+{
+        struct usb_mixer_elem_info *info;
+        __u8 unitid = (index >> 8) & 0xff;
+        __u8 control = (value >> 8) & 0xff;
+        __u8 channel = value & 0xff;
+
+        if (channel >= MAX_CHANNELS) {
+                snd_printk(KERN_DEBUG "%s(): bogus channel number %d\n",
+                                __func__, channel);
+                return;
+        }
+
+        for (info = mixer->id_elems[unitid]; info; info = info->next_id_elem) {
+                if (info->control != control)
+                        continue;
+
+                switch (attribute) {
+                case UAC2_CS_CUR:
+                        /* invalidate cache, so the value is read from the device */
+                        if (channel)
+                                info->cached &= ~(1 << channel);
+                        else /* master channel */
+                                info->cached = 0;
+
+                        snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
+                                        info->elem_id);
+                        break;
+
+                case UAC2_CS_RANGE:
+                        /* TODO */
+                        break;
+
+                case UAC2_CS_MEM:
+                        /* TODO */
+                        break;
+
+                default:
+                        snd_printk(KERN_DEBUG "unknown attribute %d in interrupt\n",
+                                                attribute);
+                        break;
+                } /* switch */
+        }
+}
+
+static void snd_usb_mixer_interrupt(struct urb *urb)
 {
         struct usb_mixer_interface *mixer = urb->context;
+        int len = urb->actual_length;
+
+        if (urb->status != 0)
+                goto requeue;
 
-        if (urb->status == 0) {
-                u8 *buf = urb->transfer_buffer;
-                int i;
+        if (mixer->protocol == UAC_VERSION_1) {
+                struct uac1_status_word *status;
 
-                for (i = urb->actual_length; i >= 2; buf += 2, i -= 2) {
+                for (status = urb->transfer_buffer;
+                     len >= sizeof(*status);
+                     len -= sizeof(*status), status++) {
                         snd_printd(KERN_DEBUG "status interrupt: %02x %02x\n",
-                                   buf[0], buf[1]);
+                                                status->bStatusType,
+                                                status->bOriginator);
+
                         /* ignore any notifications not from the control interface */
-                        if ((buf[0] & 0x0f) != 0)
+                        if ((status->bStatusType & UAC1_STATUS_TYPE_ORIG_MASK) !=
+                                UAC1_STATUS_TYPE_ORIG_AUDIO_CONTROL_IF)
                                 continue;
-                        if (!(buf[0] & 0x40))
-                                snd_usb_mixer_notify_id(mixer, buf[1]);
+
+                        if (status->bStatusType & UAC1_STATUS_TYPE_MEM_CHANGED)
+                                snd_usb_mixer_rc_memory_change(mixer, status->bOriginator);
                         else
-                                snd_usb_mixer_rc_memory_change(mixer, buf[1]);
+                                snd_usb_mixer_notify_id(mixer, status->bOriginator);
+                }
+        } else { /* UAC_VERSION_2 */
+                struct uac2_interrupt_data_msg *msg;
+
+                for (msg = urb->transfer_buffer;
+                     len >= sizeof(*msg);
+                     len -= sizeof(*msg), msg++) {
+                        /* drop vendor specific and endpoint requests */
+                        if ((msg->bInfo & UAC2_INTERRUPT_DATA_MSG_VENDOR) ||
+                            (msg->bInfo & UAC2_INTERRUPT_DATA_MSG_EP))
+                                continue;
+
+                        snd_usb_mixer_interrupt_v2(mixer, msg->bAttribute,
+                                                   le16_to_cpu(msg->wValue),
+                                                   le16_to_cpu(msg->wIndex));
                 }
         }
+
+requeue:
         if (urb->status != -ENOENT && urb->status != -ECONNRESET) {
                 urb->dev = mixer->chip->dev;
                 usb_submit_urb(urb, GFP_ATOMIC);
@@ -2023,7 +2095,7 @@ static int snd_usb_mixer_status_create(struct usb_mixer_interface *mixer)
         usb_fill_int_urb(mixer->urb, mixer->chip->dev,
                          usb_rcvintpipe(mixer->chip->dev, epnum),
                          transfer_buffer, buffer_length,
-                         snd_usb_mixer_status_complete, mixer, ep->bInterval);
+                         snd_usb_mixer_interrupt, mixer, ep->bInterval);
         usb_submit_urb(mixer->urb, GFP_KERNEL);
         return 0;
 }