Fixed MTP to work with TWRP

sound/isa/wavefront/wavefront_midi.c

@@ -0,0 +1,577 @@
+/*
+ * Copyright (C) by Paul Barton-Davis 1998-1999
+ *
+ * This file is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
+ * Version 2 (June 1991). See the "COPYING" file distributed with this
+ * software for more info.  
+ */
+
+/* The low level driver for the WaveFront ICS2115 MIDI interface(s)
+ *
+ * Note that there is also an MPU-401 emulation (actually, a UART-401
+ * emulation) on the CS4232 on the Tropez and Tropez Plus. This code
+ * has nothing to do with that interface at all.
+ *
+ * The interface is essentially just a UART-401, but is has the
+ * interesting property of supporting what Turtle Beach called
+ * "Virtual MIDI" mode. In this mode, there are effectively *two*
+ * MIDI buses accessible via the interface, one that is routed
+ * solely to/from the external WaveFront synthesizer and the other
+ * corresponding to the pin/socket connector used to link external
+ * MIDI devices to the board.
+ *
+ * This driver fully supports this mode, allowing two distinct MIDI
+ * busses to be used completely independently, giving 32 channels of
+ * MIDI routing, 16 to the WaveFront synth and 16 to the external MIDI
+ * bus. The devices are named /dev/snd/midiCnD0 and /dev/snd/midiCnD1,
+ * where `n' is the card number. Note that the device numbers may be
+ * something other than 0 and 1 if the CS4232 UART/MPU-401 interface
+ * is enabled.
+ *
+ * Switching between the two is accomplished externally by the driver
+ * using the two otherwise unused MIDI bytes. See the code for more details.
+ *
+ * NOTE: VIRTUAL MIDI MODE IS ON BY DEFAULT (see lowlevel/isa/wavefront.c)
+ *
+ * The main reason to turn off Virtual MIDI mode is when you want to
+ * tightly couple the WaveFront synth with an external MIDI
+ * device. You won't be able to distinguish the source of any MIDI
+ * data except via SysEx ID, but thats probably OK, since for the most
+ * part, the WaveFront won't be sending any MIDI data at all.
+ *  
+ * The main reason to turn on Virtual MIDI Mode is to provide two
+ * completely independent 16-channel MIDI buses, one to the
+ * WaveFront and one to any external MIDI devices. Given the 32
+ * voice nature of the WaveFront, its pretty easy to find a use
+ * for all 16 channels driving just that synth.
+ *  
+ */
+
+#include <asm/io.h>
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/wait.h>
+#include <sound/core.h>
+#include <sound/snd_wavefront.h>
+
+static inline int 
+wf_mpu_status (snd_wavefront_midi_t *midi)
+
+{
+	return inb (midi->mpu_status_port);
+}
+
+static inline int 
+input_avail (snd_wavefront_midi_t *midi)
+
+{
+	return !(wf_mpu_status(midi) & INPUT_AVAIL);
+}
+
+static inline int
+output_ready (snd_wavefront_midi_t *midi)
+
+{
+	return !(wf_mpu_status(midi) & OUTPUT_READY);
+}
+
+static inline int 
+read_data (snd_wavefront_midi_t *midi)
+
+{
+	return inb (midi->mpu_data_port);
+}
+
+static inline void 
+write_data (snd_wavefront_midi_t *midi, unsigned char byte)
+
+{
+	outb (byte, midi->mpu_data_port);
+}
+
+static snd_wavefront_midi_t *
+get_wavefront_midi (struct snd_rawmidi_substream *substream)
+
+{
+	struct snd_card *card;
+	snd_wavefront_card_t *acard;
+
+	if (substream == NULL || substream->rmidi == NULL) 
+	        return NULL;
+
+	card = substream->rmidi->card;
+
+	if (card == NULL) 
+	        return NULL;
+
+	if (card->private_data == NULL) 
+ 	        return NULL;
+
+	acard = card->private_data;
+
+	return &acard->wavefront.midi;
+}
+
+static void snd_wavefront_midi_output_write(snd_wavefront_card_t *card)
+{
+	snd_wavefront_midi_t *midi = &card->wavefront.midi;
+	snd_wavefront_mpu_id  mpu;
+	unsigned long flags;
+	unsigned char midi_byte;
+	int max = 256, mask = 1;
+	int timeout;
+
+	/* Its not OK to try to change the status of "virtuality" of
+	   the MIDI interface while we're outputting stuff.  See
+	   snd_wavefront_midi_{enable,disable}_virtual () for the
+	   other half of this.  
+
+	   The first loop attempts to flush any data from the
+	   current output device, and then the second 
+	   emits the switch byte (if necessary), and starts
+	   outputting data for the output device currently in use.
+	*/
+
+	if (midi->substream_output[midi->output_mpu] == NULL) {
+		goto __second;
+	}
+
+	while (max > 0) {
+
+		/* XXX fix me - no hard timing loops allowed! */
+
+		for (timeout = 30000; timeout > 0; timeout--) {
+			if (output_ready (midi))
+				break;
+		}
+	
+		spin_lock_irqsave (&midi->virtual, flags);
+		if ((midi->mode[midi->output_mpu] & MPU401_MODE_OUTPUT) == 0) {
+			spin_unlock_irqrestore (&midi->virtual, flags);
+			goto __second;
+		}
+		if (output_ready (midi)) {
+			if (snd_rawmidi_transmit(midi->substream_output[midi->output_mpu], &midi_byte, 1) == 1) {
+				if (!midi->isvirtual ||
+					(midi_byte != WF_INTERNAL_SWITCH &&
+					 midi_byte != WF_EXTERNAL_SWITCH))
+					write_data(midi, midi_byte);
+				max--;
+			} else {
+				if (midi->istimer) {
+					if (--midi->istimer <= 0)
+						del_timer(&midi->timer);
+				}
+				midi->mode[midi->output_mpu] &= ~MPU401_MODE_OUTPUT_TRIGGER;
+				spin_unlock_irqrestore (&midi->virtual, flags);
+				goto __second;
+			}
+		} else {
+			spin_unlock_irqrestore (&midi->virtual, flags);
+			return;
+		}
+		spin_unlock_irqrestore (&midi->virtual, flags);
+	}
+
+      __second:
+
+	if (midi->substream_output[!midi->output_mpu] == NULL) {
+		return;
+	}
+
+	while (max > 0) {
+
+		/* XXX fix me - no hard timing loops allowed! */
+
+		for (timeout = 30000; timeout > 0; timeout--) {
+			if (output_ready (midi))
+				break;
+		}
+	
+		spin_lock_irqsave (&midi->virtual, flags);
+		if (!midi->isvirtual)
+			mask = 0;
+		mpu = midi->output_mpu ^ mask;
+		mask = 0;	/* don't invert the value from now */
+		if ((midi->mode[mpu] & MPU401_MODE_OUTPUT) == 0) {
+			spin_unlock_irqrestore (&midi->virtual, flags);
+			return;
+		}
+		if (snd_rawmidi_transmit_empty(midi->substream_output[mpu]))
+			goto __timer;
+		if (output_ready (midi)) {
+			if (mpu != midi->output_mpu) {
+				write_data(midi, mpu == internal_mpu ?
+							WF_INTERNAL_SWITCH :
+							WF_EXTERNAL_SWITCH);
+				midi->output_mpu = mpu;
+			} else if (snd_rawmidi_transmit(midi->substream_output[mpu], &midi_byte, 1) == 1) {
+				if (!midi->isvirtual ||
+					(midi_byte != WF_INTERNAL_SWITCH &&
+					 midi_byte != WF_EXTERNAL_SWITCH))
+					write_data(midi, midi_byte);
+				max--;
+			} else {
+			      __timer:
+				if (midi->istimer) {
+					if (--midi->istimer <= 0)
+						del_timer(&midi->timer);
+				}
+				midi->mode[mpu] &= ~MPU401_MODE_OUTPUT_TRIGGER;
+				spin_unlock_irqrestore (&midi->virtual, flags);
+				return;
+			}
+		} else {
+			spin_unlock_irqrestore (&midi->virtual, flags);
+			return;
+		}
+		spin_unlock_irqrestore (&midi->virtual, flags);
+	}
+}
+
+static int snd_wavefront_midi_input_open(struct snd_rawmidi_substream *substream)
+{
+	unsigned long flags;
+	snd_wavefront_midi_t *midi;
+	snd_wavefront_mpu_id mpu;
+
+	if (snd_BUG_ON(!substream || !substream->rmidi))
+		return -ENXIO;
+	if (snd_BUG_ON(!substream->rmidi->private_data))
+		return -ENXIO;
+
+	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
+
+	if ((midi = get_wavefront_midi (substream)) == NULL)
+	        return -EIO;
+
+	spin_lock_irqsave (&midi->open, flags);
+	midi->mode[mpu] |= MPU401_MODE_INPUT;
+	midi->substream_input[mpu] = substream;
+	spin_unlock_irqrestore (&midi->open, flags);
+
+	return 0;
+}
+
+static int snd_wavefront_midi_output_open(struct snd_rawmidi_substream *substream)
+{
+	unsigned long flags;
+	snd_wavefront_midi_t *midi;
+	snd_wavefront_mpu_id mpu;
+
+	if (snd_BUG_ON(!substream || !substream->rmidi))
+		return -ENXIO;
+	if (snd_BUG_ON(!substream->rmidi->private_data))
+		return -ENXIO;
+
+	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
+
+	if ((midi = get_wavefront_midi (substream)) == NULL)
+	        return -EIO;
+
+	spin_lock_irqsave (&midi->open, flags);
+	midi->mode[mpu] |= MPU401_MODE_OUTPUT;
+	midi->substream_output[mpu] = substream;
+	spin_unlock_irqrestore (&midi->open, flags);
+
+	return 0;
+}
+
+static int snd_wavefront_midi_input_close(struct snd_rawmidi_substream *substream)
+{
+	unsigned long flags;
+	snd_wavefront_midi_t *midi;
+	snd_wavefront_mpu_id mpu;
+
+	if (snd_BUG_ON(!substream || !substream->rmidi))
+		return -ENXIO;
+	if (snd_BUG_ON(!substream->rmidi->private_data))
+		return -ENXIO;
+
+	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
+
+	if ((midi = get_wavefront_midi (substream)) == NULL)
+	        return -EIO;
+
+	spin_lock_irqsave (&midi->open, flags);
+	midi->mode[mpu] &= ~MPU401_MODE_INPUT;
+	spin_unlock_irqrestore (&midi->open, flags);
+
+	return 0;
+}
+
+static int snd_wavefront_midi_output_close(struct snd_rawmidi_substream *substream)
+{
+	unsigned long flags;
+	snd_wavefront_midi_t *midi;
+	snd_wavefront_mpu_id mpu;
+
+	if (snd_BUG_ON(!substream || !substream->rmidi))
+		return -ENXIO;
+	if (snd_BUG_ON(!substream->rmidi->private_data))
+		return -ENXIO;
+
+	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
+
+	if ((midi = get_wavefront_midi (substream)) == NULL)
+	        return -EIO;
+
+	spin_lock_irqsave (&midi->open, flags);
+	midi->mode[mpu] &= ~MPU401_MODE_OUTPUT;
+	spin_unlock_irqrestore (&midi->open, flags);
+	return 0;
+}
+
+static void snd_wavefront_midi_input_trigger(struct snd_rawmidi_substream *substream, int up)
+{
+	unsigned long flags;
+	snd_wavefront_midi_t *midi;
+	snd_wavefront_mpu_id mpu;
+
+	if (substream == NULL || substream->rmidi == NULL) 
+	        return;
+
+	if (substream->rmidi->private_data == NULL)
+	        return;
+
+	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
+
+	if ((midi = get_wavefront_midi (substream)) == NULL) {
+		return;
+	}
+
+	spin_lock_irqsave (&midi->virtual, flags);
+	if (up) {
+		midi->mode[mpu] |= MPU401_MODE_INPUT_TRIGGER;
+	} else {
+		midi->mode[mpu] &= ~MPU401_MODE_INPUT_TRIGGER;
+	}
+	spin_unlock_irqrestore (&midi->virtual, flags);
+}
+
+static void snd_wavefront_midi_output_timer(unsigned long data)
+{
+	snd_wavefront_card_t *card = (snd_wavefront_card_t *)data;
+	snd_wavefront_midi_t *midi = &card->wavefront.midi;
+	unsigned long flags;
+	
+	spin_lock_irqsave (&midi->virtual, flags);
+	midi->timer.expires = 1 + jiffies;
+	add_timer(&midi->timer);
+	spin_unlock_irqrestore (&midi->virtual, flags);
+	snd_wavefront_midi_output_write(card);
+}
+
+static void snd_wavefront_midi_output_trigger(struct snd_rawmidi_substream *substream, int up)
+{
+	unsigned long flags;
+	snd_wavefront_midi_t *midi;
+	snd_wavefront_mpu_id mpu;
+
+	if (substream == NULL || substream->rmidi == NULL) 
+	        return;
+
+	if (substream->rmidi->private_data == NULL)
+	        return;
+
+	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
+
+	if ((midi = get_wavefront_midi (substream)) == NULL) {
+		return;
+	}
+
+	spin_lock_irqsave (&midi->virtual, flags);
+	if (up) {
+		if ((midi->mode[mpu] & MPU401_MODE_OUTPUT_TRIGGER) == 0) {
+			if (!midi->istimer) {
+				init_timer(&midi->timer);
+				midi->timer.function = snd_wavefront_midi_output_timer;
+				midi->timer.data = (unsigned long) substream->rmidi->card->private_data;
+				midi->timer.expires = 1 + jiffies;
+				add_timer(&midi->timer);
+			}
+			midi->istimer++;
+			midi->mode[mpu] |= MPU401_MODE_OUTPUT_TRIGGER;
+		}
+	} else {
+		midi->mode[mpu] &= ~MPU401_MODE_OUTPUT_TRIGGER;
+	}
+	spin_unlock_irqrestore (&midi->virtual, flags);
+
+	if (up)
+		snd_wavefront_midi_output_write((snd_wavefront_card_t *)substream->rmidi->card->private_data);
+}
+
+void
+snd_wavefront_midi_interrupt (snd_wavefront_card_t *card)
+
+{
+	unsigned long flags;
+	snd_wavefront_midi_t *midi;
+	static struct snd_rawmidi_substream *substream = NULL;
+	static int mpu = external_mpu; 
+	int max = 128;
+	unsigned char byte;
+
+	midi = &card->wavefront.midi;
+
+	if (!input_avail (midi)) { /* not for us */
+		snd_wavefront_midi_output_write(card);
+		return;
+	}
+
+	spin_lock_irqsave (&midi->virtual, flags);
+	while (--max) {
+
+		if (input_avail (midi)) {
+			byte = read_data (midi);
+
+			if (midi->isvirtual) {				
+				if (byte == WF_EXTERNAL_SWITCH) {
+					substream = midi->substream_input[external_mpu];
+					mpu = external_mpu;
+				} else if (byte == WF_INTERNAL_SWITCH) { 
+					substream = midi->substream_output[internal_mpu];
+					mpu = internal_mpu;
+				} /* else just leave it as it is */
+			} else {
+				substream = midi->substream_input[internal_mpu];
+				mpu = internal_mpu;
+			}
+
+			if (substream == NULL) {
+				continue;
+			}
+
+			if (midi->mode[mpu] & MPU401_MODE_INPUT_TRIGGER) {
+				snd_rawmidi_receive(substream, &byte, 1);
+			}
+		} else {
+			break;
+		}
+	} 
+	spin_unlock_irqrestore (&midi->virtual, flags);
+
+	snd_wavefront_midi_output_write(card);
+}
+
+void
+snd_wavefront_midi_enable_virtual (snd_wavefront_card_t *card)
+
+{
+	unsigned long flags;
+
+	spin_lock_irqsave (&card->wavefront.midi.virtual, flags);
+	card->wavefront.midi.isvirtual = 1;
+	card->wavefront.midi.output_mpu = internal_mpu;
+	card->wavefront.midi.input_mpu = internal_mpu;
+	spin_unlock_irqrestore (&card->wavefront.midi.virtual, flags);
+}
+
+void
+snd_wavefront_midi_disable_virtual (snd_wavefront_card_t *card)
+
+{
+	unsigned long flags;
+
+	spin_lock_irqsave (&card->wavefront.midi.virtual, flags);
+	// snd_wavefront_midi_input_close (card->ics2115_external_rmidi);
+	// snd_wavefront_midi_output_close (card->ics2115_external_rmidi);
+	card->wavefront.midi.isvirtual = 0;
+	spin_unlock_irqrestore (&card->wavefront.midi.virtual, flags);
+}
+
+int
+snd_wavefront_midi_start (snd_wavefront_card_t *card)
+
+{
+	int ok, i;
+	unsigned char rbuf[4], wbuf[4];
+	snd_wavefront_t *dev;
+	snd_wavefront_midi_t *midi;
+
+	dev = &card->wavefront;
+	midi = &dev->midi;
+
+	/* The ICS2115 MPU-401 interface doesn't do anything
+	   until its set into UART mode.
+	*/
+
+	/* XXX fix me - no hard timing loops allowed! */
+
+	for (i = 0; i < 30000 && !output_ready (midi); i++);
+
+	if (!output_ready (midi)) {
+		snd_printk ("MIDI interface not ready for command\n");
+		return -1;
+	}
+
+	/* Any interrupts received from now on
+	   are owned by the MIDI side of things.
+	*/
+
+	dev->interrupts_are_midi = 1;
+	
+	outb (UART_MODE_ON, midi->mpu_command_port);
+
+	for (ok = 0, i = 50000; i > 0 && !ok; i--) {
+		if (input_avail (midi)) {
+			if (read_data (midi) == MPU_ACK) {
+				ok = 1;
+				break;
+			}
+		}
+	}
+
+	if (!ok) {
+		snd_printk ("cannot set UART mode for MIDI interface");
+		dev->interrupts_are_midi = 0;
+		return -1;
+	}
+
+	/* Route external MIDI to WaveFront synth (by default) */
+    
+	if (snd_wavefront_cmd (dev, WFC_MISYNTH_ON, rbuf, wbuf)) {
+		snd_printk ("can't enable MIDI-IN-2-synth routing.\n");
+		/* XXX error ? */
+	}
+
+	/* Turn on Virtual MIDI, but first *always* turn it off,
+	   since otherwise consecutive reloads of the driver will
+	   never cause the hardware to generate the initial "internal" or 
+	   "external" source bytes in the MIDI data stream. This
+	   is pretty important, since the internal hardware generally will
+	   be used to generate none or very little MIDI output, and
+	   thus the only source of MIDI data is actually external. Without
+	   the switch bytes, the driver will think it all comes from
+	   the internal interface. Duh.
+	*/
+
+	if (snd_wavefront_cmd (dev, WFC_VMIDI_OFF, rbuf, wbuf)) { 
+		snd_printk ("virtual MIDI mode not disabled\n");
+		return 0; /* We're OK, but missing the external MIDI dev */
+	}
+
+	snd_wavefront_midi_enable_virtual (card);
+
+	if (snd_wavefront_cmd (dev, WFC_VMIDI_ON, rbuf, wbuf)) {
+		snd_printk ("cannot enable virtual MIDI mode.\n");
+		snd_wavefront_midi_disable_virtual (card);
+	} 
+	return 0;
+}
+
+struct snd_rawmidi_ops snd_wavefront_midi_output =
+{
+	.open =		snd_wavefront_midi_output_open,
+	.close =	snd_wavefront_midi_output_close,
+	.trigger =	snd_wavefront_midi_output_trigger,
+};
+
+struct snd_rawmidi_ops snd_wavefront_midi_input =
+{
+	.open =		snd_wavefront_midi_input_open,
+	.close =	snd_wavefront_midi_input_close,
+	.trigger =	snd_wavefront_midi_input_trigger,
+};
+