+static void snd_usb_soundblaster_remote_complete(struct urb *urb,
+ struct pt_regs *regs)
+{
+ struct usb_mixer_interface *mixer = urb->context;
+ /*
+ * format of remote control data:
+ * Extigy: xx 00
+ * Audigy 2 NX: 06 80 xx 00 00 00
+ */
+ int offset = mixer->rc_type == RC_EXTIGY ? 0 : 2;
+ u32 code;
+
+ if (urb->status < 0 || urb->actual_length <= offset)
+ return;
+ code = mixer->rc_buffer[offset];
+ /* the Mute button actually changes the mixer control */
+ if (code == 13)
+ snd_usb_mixer_notify_id(mixer, 18);
+ mixer->rc_code = code;
+ wmb();
+ wake_up(&mixer->rc_waitq);
+}
+
+static int snd_usb_sbrc_hwdep_open(snd_hwdep_t *hw, struct file *file)
+{
+ struct usb_mixer_interface *mixer = hw->private_data;
+
+ if (test_and_set_bit(0, &mixer->rc_hwdep_open))
+ return -EBUSY;
+ return 0;
+}
+
+static int snd_usb_sbrc_hwdep_release(snd_hwdep_t *hw, struct file *file)
+{
+ struct usb_mixer_interface *mixer = hw->private_data;
+
+ clear_bit(0, &mixer->rc_hwdep_open);
+ smp_mb__after_clear_bit();
+ return 0;
+}
+
+static long snd_usb_sbrc_hwdep_read(snd_hwdep_t *hw, char __user *buf,
+ long count, loff_t *offset)
+{
+ struct usb_mixer_interface *mixer = hw->private_data;
+ int err;
+ u32 rc_code;
+
+ if (count != 1)
+ return -EINVAL;
+ err = wait_event_interruptible(mixer->rc_waitq,
+ (rc_code = xchg(&mixer->rc_code, 0)) != 0);
+ if (err == 0) {
+ err = put_user(rc_code, buf);
+ }
+ return err < 0 ? err : count;
+}
+
+static unsigned int snd_usb_sbrc_hwdep_poll(snd_hwdep_t *hw, struct file *file,
+ poll_table *wait)
+{
+ struct usb_mixer_interface *mixer = hw->private_data;
+
+ poll_wait(file, &mixer->rc_waitq, wait);
+ return mixer->rc_code ? POLLIN | POLLRDNORM : 0;
+}
+
+static int snd_usb_soundblaster_remote_init(struct usb_mixer_interface *mixer)
+{
+ snd_hwdep_t *hwdep;
+ int err, len;
+
+ switch (le16_to_cpu(mixer->chip->dev->descriptor.idProduct)) {
+ case 0x3000:
+ mixer->rc_type = RC_EXTIGY;
+ len = 2;
+ break;
+ case 0x3020:
+ mixer->rc_type = RC_AUDIGY2NX;
+ len = 6;
+ break;
+ default:
+ return 0;
+ }
+
+ init_waitqueue_head(&mixer->rc_waitq);
+ err = snd_hwdep_new(mixer->chip->card, "SB remote control", 0, &hwdep);
+ if (err < 0)
+ return err;
+ snprintf(hwdep->name, sizeof(hwdep->name),
+ "%s remote control", mixer->chip->card->shortname);
+ hwdep->iface = SNDRV_HWDEP_IFACE_SB_RC;
+ hwdep->private_data = mixer;
+ hwdep->ops.read = snd_usb_sbrc_hwdep_read;
+ hwdep->ops.open = snd_usb_sbrc_hwdep_open;
+ hwdep->ops.release = snd_usb_sbrc_hwdep_release;
+ hwdep->ops.poll = snd_usb_sbrc_hwdep_poll;
+
+ mixer->rc_urb = usb_alloc_urb(0, GFP_KERNEL);
+ if (!mixer->rc_urb)
+ return -ENOMEM;
+ mixer->rc_setup_packet = kmalloc(sizeof(*mixer->rc_setup_packet), GFP_KERNEL);
+ if (!mixer->rc_setup_packet) {
+ usb_free_urb(mixer->rc_urb);
+ mixer->rc_urb = NULL;
+ return -ENOMEM;
+ }
+ mixer->rc_setup_packet->bRequestType =
+ USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE;
+ mixer->rc_setup_packet->bRequest = GET_MEM;
+ mixer->rc_setup_packet->wValue = cpu_to_le16(0);
+ mixer->rc_setup_packet->wIndex = cpu_to_le16(0);
+ mixer->rc_setup_packet->wLength = cpu_to_le16(len);
+ usb_fill_control_urb(mixer->rc_urb, mixer->chip->dev,
+ usb_rcvctrlpipe(mixer->chip->dev, 0),
+ (u8*)mixer->rc_setup_packet, mixer->rc_buffer, len,
+ snd_usb_soundblaster_remote_complete, mixer);
+ return 0;
+}
+