1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) by Paul Barton-Davis 1998-1999
4 */
5
6/* The low level driver for the WaveFront ICS2115 MIDI interface(s)
7 *
8 * Note that there is also an MPU-401 emulation (actually, a UART-401
9 * emulation) on the CS4232 on the Tropez and Tropez Plus. This code
10 * has nothing to do with that interface at all.
11 *
12 * The interface is essentially just a UART-401, but is has the
13 * interesting property of supporting what Turtle Beach called
14 * "Virtual MIDI" mode. In this mode, there are effectively *two*
15 * MIDI buses accessible via the interface, one that is routed
16 * solely to/from the external WaveFront synthesizer and the other
17 * corresponding to the pin/socket connector used to link external
18 * MIDI devices to the board.
19 *
20 * This driver fully supports this mode, allowing two distinct MIDI
21 * busses to be used completely independently, giving 32 channels of
22 * MIDI routing, 16 to the WaveFront synth and 16 to the external MIDI
23 * bus. The devices are named /dev/snd/midiCnD0 and /dev/snd/midiCnD1,
24 * where `n' is the card number. Note that the device numbers may be
25 * something other than 0 and 1 if the CS4232 UART/MPU-401 interface
26 * is enabled.
27 *
28 * Switching between the two is accomplished externally by the driver
29 * using the two otherwise unused MIDI bytes. See the code for more details.
30 *
31 * NOTE: VIRTUAL MIDI MODE IS ON BY DEFAULT (see lowlevel/isa/wavefront.c)
32 *
33 * The main reason to turn off Virtual MIDI mode is when you want to
34 * tightly couple the WaveFront synth with an external MIDI
35 * device. You won't be able to distinguish the source of any MIDI
36 * data except via SysEx ID, but thats probably OK, since for the most
37 * part, the WaveFront won't be sending any MIDI data at all.
38 *
39 * The main reason to turn on Virtual MIDI Mode is to provide two
40 * completely independent 16-channel MIDI buses, one to the
41 * WaveFront and one to any external MIDI devices. Given the 32
42 * voice nature of the WaveFront, its pretty easy to find a use
43 * for all 16 channels driving just that synth.
44 *
45 */
46
47#include <linux/io.h>
48#include <linux/init.h>
49#include <linux/time.h>
50#include <linux/wait.h>
51#include <sound/core.h>
52#include <sound/snd_wavefront.h>
53
54static inline int
55wf_mpu_status (snd_wavefront_midi_t *midi)
56
57{
58	return inb (midi->mpu_status_port);
59}
60
61static inline int
62input_avail (snd_wavefront_midi_t *midi)
63
64{
65	return !(wf_mpu_status(midi) & INPUT_AVAIL);
66}
67
68static inline int
69output_ready (snd_wavefront_midi_t *midi)
70
71{
72	return !(wf_mpu_status(midi) & OUTPUT_READY);
73}
74
75static inline int
76read_data (snd_wavefront_midi_t *midi)
77
78{
79	return inb (midi->mpu_data_port);
80}
81
82static inline void
83write_data (snd_wavefront_midi_t *midi, unsigned char byte)
84
85{
86	outb (byte, midi->mpu_data_port);
87}
88
89static snd_wavefront_midi_t *
90get_wavefront_midi (struct snd_rawmidi_substream *substream)
91
92{
93	struct snd_card *card;
94	snd_wavefront_card_t *acard;
95
96	if (substream == NULL || substream->rmidi == NULL)
97	        return NULL;
98
99	card = substream->rmidi->card;
100
101	if (card == NULL)
102	        return NULL;
103
104	if (card->private_data == NULL)
105 	        return NULL;
106
107	acard = card->private_data;
108
109	return &acard->wavefront.midi;
110}
111
112static void snd_wavefront_midi_output_write(snd_wavefront_card_t *card)
113{
114	snd_wavefront_midi_t *midi = &card->wavefront.midi;
115	snd_wavefront_mpu_id  mpu;
116	unsigned long flags;
117	unsigned char midi_byte;
118	int max = 256, mask = 1;
119	int timeout;
120
121	/* Its not OK to try to change the status of "virtuality" of
122	   the MIDI interface while we're outputting stuff.  See
123	   snd_wavefront_midi_{enable,disable}_virtual () for the
124	   other half of this.
125
126	   The first loop attempts to flush any data from the
127	   current output device, and then the second
128	   emits the switch byte (if necessary), and starts
129	   outputting data for the output device currently in use.
130	*/
131
132	if (midi->substream_output[midi->output_mpu] == NULL) {
133		goto __second;
134	}
135
136	while (max > 0) {
137
138		/* XXX fix me - no hard timing loops allowed! */
139
140		for (timeout = 30000; timeout > 0; timeout--) {
141			if (output_ready (midi))
142				break;
143		}
144
145		spin_lock_irqsave (&midi->virtual, flags);
146		if ((midi->mode[midi->output_mpu] & MPU401_MODE_OUTPUT) == 0) {
147			spin_unlock_irqrestore (&midi->virtual, flags);
148			goto __second;
149		}
150		if (output_ready (midi)) {
151			if (snd_rawmidi_transmit(midi->substream_output[midi->output_mpu], &midi_byte, 1) == 1) {
152				if (!midi->isvirtual ||
153					(midi_byte != WF_INTERNAL_SWITCH &&
154					 midi_byte != WF_EXTERNAL_SWITCH))
155					write_data(midi, midi_byte);
156				max--;
157			} else {
158				if (midi->istimer) {
159					if (--midi->istimer <= 0)
160						del_timer(&midi->timer);
161				}
162				midi->mode[midi->output_mpu] &= ~MPU401_MODE_OUTPUT_TRIGGER;
163				spin_unlock_irqrestore (&midi->virtual, flags);
164				goto __second;
165			}
166		} else {
167			spin_unlock_irqrestore (&midi->virtual, flags);
168			return;
169		}
170		spin_unlock_irqrestore (&midi->virtual, flags);
171	}
172
173      __second:
174
175	if (midi->substream_output[!midi->output_mpu] == NULL) {
176		return;
177	}
178
179	while (max > 0) {
180
181		/* XXX fix me - no hard timing loops allowed! */
182
183		for (timeout = 30000; timeout > 0; timeout--) {
184			if (output_ready (midi))
185				break;
186		}
187
188		spin_lock_irqsave (&midi->virtual, flags);
189		if (!midi->isvirtual)
190			mask = 0;
191		mpu = midi->output_mpu ^ mask;
192		mask = 0;	/* don't invert the value from now */
193		if ((midi->mode[mpu] & MPU401_MODE_OUTPUT) == 0) {
194			spin_unlock_irqrestore (&midi->virtual, flags);
195			return;
196		}
197		if (snd_rawmidi_transmit_empty(midi->substream_output[mpu]))
198			goto __timer;
199		if (output_ready (midi)) {
200			if (mpu != midi->output_mpu) {
201				write_data(midi, mpu == internal_mpu ?
202							WF_INTERNAL_SWITCH :
203							WF_EXTERNAL_SWITCH);
204				midi->output_mpu = mpu;
205			} else if (snd_rawmidi_transmit(midi->substream_output[mpu], &midi_byte, 1) == 1) {
206				if (!midi->isvirtual ||
207					(midi_byte != WF_INTERNAL_SWITCH &&
208					 midi_byte != WF_EXTERNAL_SWITCH))
209					write_data(midi, midi_byte);
210				max--;
211			} else {
212			      __timer:
213				if (midi->istimer) {
214					if (--midi->istimer <= 0)
215						del_timer(&midi->timer);
216				}
217				midi->mode[mpu] &= ~MPU401_MODE_OUTPUT_TRIGGER;
218				spin_unlock_irqrestore (&midi->virtual, flags);
219				return;
220			}
221		} else {
222			spin_unlock_irqrestore (&midi->virtual, flags);
223			return;
224		}
225		spin_unlock_irqrestore (&midi->virtual, flags);
226	}
227}
228
229static int snd_wavefront_midi_input_open(struct snd_rawmidi_substream *substream)
230{
231	unsigned long flags;
232	snd_wavefront_midi_t *midi;
233	snd_wavefront_mpu_id mpu;
234
235	if (snd_BUG_ON(!substream || !substream->rmidi))
236		return -ENXIO;
237	if (snd_BUG_ON(!substream->rmidi->private_data))
238		return -ENXIO;
239
240	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
241
242	midi = get_wavefront_midi(substream);
243	if (!midi)
244	        return -EIO;
245
246	spin_lock_irqsave (&midi->open, flags);
247	midi->mode[mpu] |= MPU401_MODE_INPUT;
248	midi->substream_input[mpu] = substream;
249	spin_unlock_irqrestore (&midi->open, flags);
250
251	return 0;
252}
253
254static int snd_wavefront_midi_output_open(struct snd_rawmidi_substream *substream)
255{
256	unsigned long flags;
257	snd_wavefront_midi_t *midi;
258	snd_wavefront_mpu_id mpu;
259
260	if (snd_BUG_ON(!substream || !substream->rmidi))
261		return -ENXIO;
262	if (snd_BUG_ON(!substream->rmidi->private_data))
263		return -ENXIO;
264
265	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
266
267	midi = get_wavefront_midi(substream);
268	if (!midi)
269	        return -EIO;
270
271	spin_lock_irqsave (&midi->open, flags);
272	midi->mode[mpu] |= MPU401_MODE_OUTPUT;
273	midi->substream_output[mpu] = substream;
274	spin_unlock_irqrestore (&midi->open, flags);
275
276	return 0;
277}
278
279static int snd_wavefront_midi_input_close(struct snd_rawmidi_substream *substream)
280{
281	unsigned long flags;
282	snd_wavefront_midi_t *midi;
283	snd_wavefront_mpu_id mpu;
284
285	if (snd_BUG_ON(!substream || !substream->rmidi))
286		return -ENXIO;
287	if (snd_BUG_ON(!substream->rmidi->private_data))
288		return -ENXIO;
289
290	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
291
292	midi = get_wavefront_midi(substream);
293	if (!midi)
294	        return -EIO;
295
296	spin_lock_irqsave (&midi->open, flags);
297	midi->mode[mpu] &= ~MPU401_MODE_INPUT;
298	spin_unlock_irqrestore (&midi->open, flags);
299
300	return 0;
301}
302
303static int snd_wavefront_midi_output_close(struct snd_rawmidi_substream *substream)
304{
305	unsigned long flags;
306	snd_wavefront_midi_t *midi;
307	snd_wavefront_mpu_id mpu;
308
309	if (snd_BUG_ON(!substream || !substream->rmidi))
310		return -ENXIO;
311	if (snd_BUG_ON(!substream->rmidi->private_data))
312		return -ENXIO;
313
314	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
315
316	midi = get_wavefront_midi(substream);
317	if (!midi)
318	        return -EIO;
319
320	spin_lock_irqsave (&midi->open, flags);
321	midi->mode[mpu] &= ~MPU401_MODE_OUTPUT;
322	spin_unlock_irqrestore (&midi->open, flags);
323	return 0;
324}
325
326static void snd_wavefront_midi_input_trigger(struct snd_rawmidi_substream *substream, int up)
327{
328	unsigned long flags;
329	snd_wavefront_midi_t *midi;
330	snd_wavefront_mpu_id mpu;
331
332	if (substream == NULL || substream->rmidi == NULL)
333	        return;
334
335	if (substream->rmidi->private_data == NULL)
336	        return;
337
338	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
339
340	midi = get_wavefront_midi(substream);
341	if (!midi)
342		return;
343
344	spin_lock_irqsave (&midi->virtual, flags);
345	if (up) {
346		midi->mode[mpu] |= MPU401_MODE_INPUT_TRIGGER;
347	} else {
348		midi->mode[mpu] &= ~MPU401_MODE_INPUT_TRIGGER;
349	}
350	spin_unlock_irqrestore (&midi->virtual, flags);
351}
352
353static void snd_wavefront_midi_output_timer(struct timer_list *t)
354{
355	snd_wavefront_midi_t *midi = from_timer(midi, t, timer);
356	snd_wavefront_card_t *card = midi->timer_card;
357	unsigned long flags;
358
359	spin_lock_irqsave (&midi->virtual, flags);
360	mod_timer(&midi->timer, 1 + jiffies);
361	spin_unlock_irqrestore (&midi->virtual, flags);
362	snd_wavefront_midi_output_write(card);
363}
364
365static void snd_wavefront_midi_output_trigger(struct snd_rawmidi_substream *substream, int up)
366{
367	unsigned long flags;
368	snd_wavefront_midi_t *midi;
369	snd_wavefront_mpu_id mpu;
370
371	if (substream == NULL || substream->rmidi == NULL)
372	        return;
373
374	if (substream->rmidi->private_data == NULL)
375	        return;
376
377	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
378
379	midi = get_wavefront_midi(substream);
380	if (!midi)
381		return;
382
383	spin_lock_irqsave (&midi->virtual, flags);
384	if (up) {
385		if ((midi->mode[mpu] & MPU401_MODE_OUTPUT_TRIGGER) == 0) {
386			if (!midi->istimer) {
387				timer_setup(&midi->timer,
388					    snd_wavefront_midi_output_timer,
389					    0);
390				mod_timer(&midi->timer, 1 + jiffies);
391			}
392			midi->istimer++;
393			midi->mode[mpu] |= MPU401_MODE_OUTPUT_TRIGGER;
394		}
395	} else {
396		midi->mode[mpu] &= ~MPU401_MODE_OUTPUT_TRIGGER;
397	}
398	spin_unlock_irqrestore (&midi->virtual, flags);
399
400	if (up)
401		snd_wavefront_midi_output_write((snd_wavefront_card_t *)substream->rmidi->card->private_data);
402}
403
404void
405snd_wavefront_midi_interrupt (snd_wavefront_card_t *card)
406
407{
408	unsigned long flags;
409	snd_wavefront_midi_t *midi;
410	static struct snd_rawmidi_substream *substream = NULL;
411	static int mpu = external_mpu;
412	int max = 128;
413	unsigned char byte;
414
415	midi = &card->wavefront.midi;
416
417	if (!input_avail (midi)) { /* not for us */
418		snd_wavefront_midi_output_write(card);
419		return;
420	}
421
422	spin_lock_irqsave (&midi->virtual, flags);
423	while (--max) {
424
425		if (input_avail (midi)) {
426			byte = read_data (midi);
427
428			if (midi->isvirtual) {
429				if (byte == WF_EXTERNAL_SWITCH) {
430					substream = midi->substream_input[external_mpu];
431					mpu = external_mpu;
432				} else if (byte == WF_INTERNAL_SWITCH) {
433					substream = midi->substream_output[internal_mpu];
434					mpu = internal_mpu;
435				} /* else just leave it as it is */
436			} else {
437				substream = midi->substream_input[internal_mpu];
438				mpu = internal_mpu;
439			}
440
441			if (substream == NULL) {
442				continue;
443			}
444
445			if (midi->mode[mpu] & MPU401_MODE_INPUT_TRIGGER) {
446				snd_rawmidi_receive(substream, &byte, 1);
447			}
448		} else {
449			break;
450		}
451	}
452	spin_unlock_irqrestore (&midi->virtual, flags);
453
454	snd_wavefront_midi_output_write(card);
455}
456
457void
458snd_wavefront_midi_enable_virtual (snd_wavefront_card_t *card)
459
460{
461	unsigned long flags;
462
463	spin_lock_irqsave (&card->wavefront.midi.virtual, flags);
464	card->wavefront.midi.isvirtual = 1;
465	card->wavefront.midi.output_mpu = internal_mpu;
466	card->wavefront.midi.input_mpu = internal_mpu;
467	spin_unlock_irqrestore (&card->wavefront.midi.virtual, flags);
468}
469
470void
471snd_wavefront_midi_disable_virtual (snd_wavefront_card_t *card)
472
473{
474	unsigned long flags;
475
476	spin_lock_irqsave (&card->wavefront.midi.virtual, flags);
477	// snd_wavefront_midi_input_close (card->ics2115_external_rmidi);
478	// snd_wavefront_midi_output_close (card->ics2115_external_rmidi);
479	card->wavefront.midi.isvirtual = 0;
480	spin_unlock_irqrestore (&card->wavefront.midi.virtual, flags);
481}
482
483int
484snd_wavefront_midi_start (snd_wavefront_card_t *card)
485
486{
487	int ok, i;
488	unsigned char rbuf[4], wbuf[4];
489	snd_wavefront_t *dev;
490	snd_wavefront_midi_t *midi;
491
492	dev = &card->wavefront;
493	midi = &dev->midi;
494
495	/* The ICS2115 MPU-401 interface doesn't do anything
496	   until its set into UART mode.
497	*/
498
499	/* XXX fix me - no hard timing loops allowed! */
500
501	for (i = 0; i < 30000 && !output_ready (midi); i++);
502
503	if (!output_ready (midi)) {
504		snd_printk ("MIDI interface not ready for command\n");
505		return -1;
506	}
507
508	/* Any interrupts received from now on
509	   are owned by the MIDI side of things.
510	*/
511
512	dev->interrupts_are_midi = 1;
513
514	outb (UART_MODE_ON, midi->mpu_command_port);
515
516	for (ok = 0, i = 50000; i > 0 && !ok; i--) {
517		if (input_avail (midi)) {
518			if (read_data (midi) == MPU_ACK) {
519				ok = 1;
520				break;
521			}
522		}
523	}
524
525	if (!ok) {
526		snd_printk ("cannot set UART mode for MIDI interface");
527		dev->interrupts_are_midi = 0;
528		return -1;
529	}
530
531	/* Route external MIDI to WaveFront synth (by default) */
532
533	if (snd_wavefront_cmd (dev, WFC_MISYNTH_ON, rbuf, wbuf)) {
534		snd_printk ("can't enable MIDI-IN-2-synth routing.\n");
535		/* XXX error ? */
536	}
537
538	/* Turn on Virtual MIDI, but first *always* turn it off,
539	   since otherwise consecutive reloads of the driver will
540	   never cause the hardware to generate the initial "internal" or
541	   "external" source bytes in the MIDI data stream. This
542	   is pretty important, since the internal hardware generally will
543	   be used to generate none or very little MIDI output, and
544	   thus the only source of MIDI data is actually external. Without
545	   the switch bytes, the driver will think it all comes from
546	   the internal interface. Duh.
547	*/
548
549	if (snd_wavefront_cmd (dev, WFC_VMIDI_OFF, rbuf, wbuf)) {
550		snd_printk ("virtual MIDI mode not disabled\n");
551		return 0; /* We're OK, but missing the external MIDI dev */
552	}
553
554	snd_wavefront_midi_enable_virtual (card);
555
556	if (snd_wavefront_cmd (dev, WFC_VMIDI_ON, rbuf, wbuf)) {
557		snd_printk ("cannot enable virtual MIDI mode.\n");
558		snd_wavefront_midi_disable_virtual (card);
559	}
560	return 0;
561}
562
563const struct snd_rawmidi_ops snd_wavefront_midi_output =
564{
565	.open =		snd_wavefront_midi_output_open,
566	.close =	snd_wavefront_midi_output_close,
567	.trigger =	snd_wavefront_midi_output_trigger,
568};
569
570const struct snd_rawmidi_ops snd_wavefront_midi_input =
571{
572	.open =		snd_wavefront_midi_input_open,
573	.close =	snd_wavefront_midi_input_close,
574	.trigger =	snd_wavefront_midi_input_trigger,
575};
576
577