+ * MIDI
+ */
+
+static void vt1724_midi_clear_rx(struct snd_ice1712 *ice)
+{
+ unsigned int count;
+
+ for (count = inb(ICEREG1724(ice, MPU_RXFIFO)); count > 0; --count)
+ inb(ICEREG1724(ice, MPU_DATA));
+}
+
+static inline struct snd_rawmidi_substream *
+get_rawmidi_substream(struct snd_ice1712 *ice, unsigned int stream)
+{
+ return list_first_entry(&ice->rmidi[0]->streams[stream].substreams,
+ struct snd_rawmidi_substream, list);
+}
+
+static void enable_midi_irq(struct snd_ice1712 *ice, u8 flag, int enable);
+
+static void vt1724_midi_write(struct snd_ice1712 *ice)
+{
+ struct snd_rawmidi_substream *s;
+ int count, i;
+ u8 buffer[32];
+
+ s = get_rawmidi_substream(ice, SNDRV_RAWMIDI_STREAM_OUTPUT);
+ count = 31 - inb(ICEREG1724(ice, MPU_TXFIFO));
+ if (count > 0) {
+ count = snd_rawmidi_transmit(s, buffer, count);
+ for (i = 0; i < count; ++i)
+ outb(buffer[i], ICEREG1724(ice, MPU_DATA));
+ }
+ /* mask irq when all bytes have been transmitted.
+ * enabled again in output_trigger when the new data comes in.
+ */
+ enable_midi_irq(ice, VT1724_IRQ_MPU_TX,
+ !snd_rawmidi_transmit_empty(s));
+}
+
+static void vt1724_midi_read(struct snd_ice1712 *ice)
+{
+ struct snd_rawmidi_substream *s;
+ int count, i;
+ u8 buffer[32];
+
+ s = get_rawmidi_substream(ice, SNDRV_RAWMIDI_STREAM_INPUT);
+ count = inb(ICEREG1724(ice, MPU_RXFIFO));
+ if (count > 0) {
+ count = min(count, 32);
+ for (i = 0; i < count; ++i)
+ buffer[i] = inb(ICEREG1724(ice, MPU_DATA));
+ snd_rawmidi_receive(s, buffer, count);
+ }
+}
+
+/* call with ice->reg_lock */
+static void enable_midi_irq(struct snd_ice1712 *ice, u8 flag, int enable)
+{
+ u8 mask = inb(ICEREG1724(ice, IRQMASK));
+ if (enable)
+ mask &= ~flag;
+ else
+ mask |= flag;
+ outb(mask, ICEREG1724(ice, IRQMASK));
+}
+
+static void vt1724_enable_midi_irq(struct snd_rawmidi_substream *substream,
+ u8 flag, int enable)
+{
+ struct snd_ice1712 *ice = substream->rmidi->private_data;
+
+ spin_lock_irq(&ice->reg_lock);
+ enable_midi_irq(ice, flag, enable);
+ spin_unlock_irq(&ice->reg_lock);
+}
+
+static int vt1724_midi_output_open(struct snd_rawmidi_substream *s)
+{
+ return 0;
+}
+
+static int vt1724_midi_output_close(struct snd_rawmidi_substream *s)
+{
+ return 0;
+}
+
+static void vt1724_midi_output_trigger(struct snd_rawmidi_substream *s, int up)
+{
+ struct snd_ice1712 *ice = s->rmidi->private_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ice->reg_lock, flags);
+ if (up) {
+ ice->midi_output = 1;
+ vt1724_midi_write(ice);
+ } else {
+ ice->midi_output = 0;
+ enable_midi_irq(ice, VT1724_IRQ_MPU_TX, 0);
+ }
+ spin_unlock_irqrestore(&ice->reg_lock, flags);
+}
+
+static void vt1724_midi_output_drain(struct snd_rawmidi_substream *s)
+{
+ struct snd_ice1712 *ice = s->rmidi->private_data;
+ unsigned long timeout;
+
+ vt1724_enable_midi_irq(s, VT1724_IRQ_MPU_TX, 0);
+ /* 32 bytes should be transmitted in less than about 12 ms */
+ timeout = jiffies + msecs_to_jiffies(15);
+ do {
+ if (inb(ICEREG1724(ice, MPU_CTRL)) & VT1724_MPU_TX_EMPTY)
+ break;
+ schedule_timeout_uninterruptible(1);
+ } while (time_after(timeout, jiffies));
+}
+
+static struct snd_rawmidi_ops vt1724_midi_output_ops = {
+ .open = vt1724_midi_output_open,
+ .close = vt1724_midi_output_close,
+ .trigger = vt1724_midi_output_trigger,
+ .drain = vt1724_midi_output_drain,
+};
+
+static int vt1724_midi_input_open(struct snd_rawmidi_substream *s)
+{
+ vt1724_midi_clear_rx(s->rmidi->private_data);
+ vt1724_enable_midi_irq(s, VT1724_IRQ_MPU_RX, 1);
+ return 0;
+}
+
+static int vt1724_midi_input_close(struct snd_rawmidi_substream *s)
+{
+ vt1724_enable_midi_irq(s, VT1724_IRQ_MPU_RX, 0);
+ return 0;
+}
+
+static void vt1724_midi_input_trigger(struct snd_rawmidi_substream *s, int up)
+{
+ struct snd_ice1712 *ice = s->rmidi->private_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ice->reg_lock, flags);
+ if (up) {
+ ice->midi_input = 1;
+ vt1724_midi_read(ice);
+ } else {
+ ice->midi_input = 0;
+ }
+ spin_unlock_irqrestore(&ice->reg_lock, flags);
+}
+
+static struct snd_rawmidi_ops vt1724_midi_input_ops = {
+ .open = vt1724_midi_input_open,
+ .close = vt1724_midi_input_close,
+ .trigger = vt1724_midi_input_trigger,
+};
+
+
+/*