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	if ((midi = get_wavefront_midi (substream)) == NULL)
243	        return -EIO;
244
245	spin_lock_irqsave (&midi->open, flags);
246	midi->mode[mpu] |= MPU401_MODE_INPUT;
247	midi->substream_input[mpu] = substream;
248	spin_unlock_irqrestore (&midi->open, flags);
249
250	return 0;
251}
252
253static int snd_wavefront_midi_output_open(struct snd_rawmidi_substream *substream)
254{
255	unsigned long flags;
256	snd_wavefront_midi_t *midi;
257	snd_wavefront_mpu_id mpu;
258
259	if (snd_BUG_ON(!substream || !substream->rmidi))
260		return -ENXIO;
261	if (snd_BUG_ON(!substream->rmidi->private_data))
262		return -ENXIO;
263
264	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
265
266	if ((midi = get_wavefront_midi (substream)) == NULL)
267	        return -EIO;
268
269	spin_lock_irqsave (&midi->open, flags);
270	midi->mode[mpu] |= MPU401_MODE_OUTPUT;
271	midi->substream_output[mpu] = substream;
272	spin_unlock_irqrestore (&midi->open, flags);
273
274	return 0;
275}
276
277static int snd_wavefront_midi_input_close(struct snd_rawmidi_substream *substream)
278{
279	unsigned long flags;
280	snd_wavefront_midi_t *midi;
281	snd_wavefront_mpu_id mpu;
282
283	if (snd_BUG_ON(!substream || !substream->rmidi))
284		return -ENXIO;
285	if (snd_BUG_ON(!substream->rmidi->private_data))
286		return -ENXIO;
287
288	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
289
290	if ((midi = get_wavefront_midi (substream)) == NULL)
291	        return -EIO;
292
293	spin_lock_irqsave (&midi->open, flags);
294	midi->mode[mpu] &= ~MPU401_MODE_INPUT;
295	spin_unlock_irqrestore (&midi->open, flags);
296
297	return 0;
298}
299
300static int snd_wavefront_midi_output_close(struct snd_rawmidi_substream *substream)
301{
302	unsigned long flags;
303	snd_wavefront_midi_t *midi;
304	snd_wavefront_mpu_id mpu;
305
306	if (snd_BUG_ON(!substream || !substream->rmidi))
307		return -ENXIO;
308	if (snd_BUG_ON(!substream->rmidi->private_data))
309		return -ENXIO;
310
311	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
312
313	if ((midi = get_wavefront_midi (substream)) == NULL)
314	        return -EIO;
315
316	spin_lock_irqsave (&midi->open, flags);
317	midi->mode[mpu] &= ~MPU401_MODE_OUTPUT;
318	spin_unlock_irqrestore (&midi->open, flags);
319	return 0;
320}
321
322static void snd_wavefront_midi_input_trigger(struct snd_rawmidi_substream *substream, int up)
323{
324	unsigned long flags;
325	snd_wavefront_midi_t *midi;
326	snd_wavefront_mpu_id mpu;
327
328	if (substream == NULL || substream->rmidi == NULL)
329	        return;
330
331	if (substream->rmidi->private_data == NULL)
332	        return;
333
334	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
335
336	if ((midi = get_wavefront_midi (substream)) == NULL) {
337		return;
338	}
339
340	spin_lock_irqsave (&midi->virtual, flags);
341	if (up) {
342		midi->mode[mpu] |= MPU401_MODE_INPUT_TRIGGER;
343	} else {
344		midi->mode[mpu] &= ~MPU401_MODE_INPUT_TRIGGER;
345	}
346	spin_unlock_irqrestore (&midi->virtual, flags);
347}
348
349static void snd_wavefront_midi_output_timer(struct timer_list *t)
350{
351	snd_wavefront_midi_t *midi = from_timer(midi, t, timer);
352	snd_wavefront_card_t *card = midi->timer_card;
353	unsigned long flags;
354
355	spin_lock_irqsave (&midi->virtual, flags);
356	mod_timer(&midi->timer, 1 + jiffies);
357	spin_unlock_irqrestore (&midi->virtual, flags);
358	snd_wavefront_midi_output_write(card);
359}
360
361static void snd_wavefront_midi_output_trigger(struct snd_rawmidi_substream *substream, int up)
362{
363	unsigned long flags;
364	snd_wavefront_midi_t *midi;
365	snd_wavefront_mpu_id mpu;
366
367	if (substream == NULL || substream->rmidi == NULL)
368	        return;
369
370	if (substream->rmidi->private_data == NULL)
371	        return;
372
373	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
374
375	if ((midi = get_wavefront_midi (substream)) == NULL) {
376		return;
377	}
378
379	spin_lock_irqsave (&midi->virtual, flags);
380	if (up) {
381		if ((midi->mode[mpu] & MPU401_MODE_OUTPUT_TRIGGER) == 0) {
382			if (!midi->istimer) {
383				timer_setup(&midi->timer,
384					    snd_wavefront_midi_output_timer,
385					    0);
386				mod_timer(&midi->timer, 1 + jiffies);
387			}
388			midi->istimer++;
389			midi->mode[mpu] |= MPU401_MODE_OUTPUT_TRIGGER;
390		}
391	} else {
392		midi->mode[mpu] &= ~MPU401_MODE_OUTPUT_TRIGGER;
393	}
394	spin_unlock_irqrestore (&midi->virtual, flags);
395
396	if (up)
397		snd_wavefront_midi_output_write((snd_wavefront_card_t *)substream->rmidi->card->private_data);
398}
399
400void
401snd_wavefront_midi_interrupt (snd_wavefront_card_t *card)
402
403{
404	unsigned long flags;
405	snd_wavefront_midi_t *midi;
406	static struct snd_rawmidi_substream *substream = NULL;
407	static int mpu = external_mpu;
408	int max = 128;
409	unsigned char byte;
410
411	midi = &card->wavefront.midi;
412
413	if (!input_avail (midi)) { /* not for us */
414		snd_wavefront_midi_output_write(card);
415		return;
416	}
417
418	spin_lock_irqsave (&midi->virtual, flags);
419	while (--max) {
420
421		if (input_avail (midi)) {
422			byte = read_data (midi);
423
424			if (midi->isvirtual) {
425				if (byte == WF_EXTERNAL_SWITCH) {
426					substream = midi->substream_input[external_mpu];
427					mpu = external_mpu;
428				} else if (byte == WF_INTERNAL_SWITCH) {
429					substream = midi->substream_output[internal_mpu];
430					mpu = internal_mpu;
431				} /* else just leave it as it is */
432			} else {
433				substream = midi->substream_input[internal_mpu];
434				mpu = internal_mpu;
435			}
436
437			if (substream == NULL) {
438				continue;
439			}
440
441			if (midi->mode[mpu] & MPU401_MODE_INPUT_TRIGGER) {
442				snd_rawmidi_receive(substream, &byte, 1);
443			}
444		} else {
445			break;
446		}
447	}
448	spin_unlock_irqrestore (&midi->virtual, flags);
449
450	snd_wavefront_midi_output_write(card);
451}
452
453void
454snd_wavefront_midi_enable_virtual (snd_wavefront_card_t *card)
455
456{
457	unsigned long flags;
458
459	spin_lock_irqsave (&card->wavefront.midi.virtual, flags);
460	card->wavefront.midi.isvirtual = 1;
461	card->wavefront.midi.output_mpu = internal_mpu;
462	card->wavefront.midi.input_mpu = internal_mpu;
463	spin_unlock_irqrestore (&card->wavefront.midi.virtual, flags);
464}
465
466void
467snd_wavefront_midi_disable_virtual (snd_wavefront_card_t *card)
468
469{
470	unsigned long flags;
471
472	spin_lock_irqsave (&card->wavefront.midi.virtual, flags);
473	// snd_wavefront_midi_input_close (card->ics2115_external_rmidi);
474	// snd_wavefront_midi_output_close (card->ics2115_external_rmidi);
475	card->wavefront.midi.isvirtual = 0;
476	spin_unlock_irqrestore (&card->wavefront.midi.virtual, flags);
477}
478
479int
480snd_wavefront_midi_start (snd_wavefront_card_t *card)
481
482{
483	int ok, i;
484	unsigned char rbuf[4], wbuf[4];
485	snd_wavefront_t *dev;
486	snd_wavefront_midi_t *midi;
487
488	dev = &card->wavefront;
489	midi = &dev->midi;
490
491	/* The ICS2115 MPU-401 interface doesn't do anything
492	   until its set into UART mode.
493	*/
494
495	/* XXX fix me - no hard timing loops allowed! */
496
497	for (i = 0; i < 30000 && !output_ready (midi); i++);
498
499	if (!output_ready (midi)) {
500		snd_printk ("MIDI interface not ready for command\n");
501		return -1;
502	}
503
504	/* Any interrupts received from now on
505	   are owned by the MIDI side of things.
506	*/
507
508	dev->interrupts_are_midi = 1;
509
510	outb (UART_MODE_ON, midi->mpu_command_port);
511
512	for (ok = 0, i = 50000; i > 0 && !ok; i--) {
513		if (input_avail (midi)) {
514			if (read_data (midi) == MPU_ACK) {
515				ok = 1;
516				break;
517			}
518		}
519	}
520
521	if (!ok) {
522		snd_printk ("cannot set UART mode for MIDI interface");
523		dev->interrupts_are_midi = 0;
524		return -1;
525	}
526
527	/* Route external MIDI to WaveFront synth (by default) */
528
529	if (snd_wavefront_cmd (dev, WFC_MISYNTH_ON, rbuf, wbuf)) {
530		snd_printk ("can't enable MIDI-IN-2-synth routing.\n");
531		/* XXX error ? */
532	}
533
534	/* Turn on Virtual MIDI, but first *always* turn it off,
535	   since otherwise consecutive reloads of the driver will
536	   never cause the hardware to generate the initial "internal" or
537	   "external" source bytes in the MIDI data stream. This
538	   is pretty important, since the internal hardware generally will
539	   be used to generate none or very little MIDI output, and
540	   thus the only source of MIDI data is actually external. Without
541	   the switch bytes, the driver will think it all comes from
542	   the internal interface. Duh.
543	*/
544
545	if (snd_wavefront_cmd (dev, WFC_VMIDI_OFF, rbuf, wbuf)) {
546		snd_printk ("virtual MIDI mode not disabled\n");
547		return 0; /* We're OK, but missing the external MIDI dev */
548	}
549
550	snd_wavefront_midi_enable_virtual (card);
551
552	if (snd_wavefront_cmd (dev, WFC_VMIDI_ON, rbuf, wbuf)) {
553		snd_printk ("cannot enable virtual MIDI mode.\n");
554		snd_wavefront_midi_disable_virtual (card);
555	}
556	return 0;
557}
558
559const struct snd_rawmidi_ops snd_wavefront_midi_output =
560{
561	.open =		snd_wavefront_midi_output_open,
562	.close =	snd_wavefront_midi_output_close,
563	.trigger =	snd_wavefront_midi_output_trigger,
564};
565
566const struct snd_rawmidi_ops snd_wavefront_midi_input =
567{
568	.open =		snd_wavefront_midi_input_open,
569	.close =	snd_wavefront_midi_input_close,
570	.trigger =	snd_wavefront_midi_input_trigger,
571};
572
573