1 /*
2  * Copyright (C) by Paul Barton-Davis 1998-1999
3  *
4  * This file is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
5  * Version 2 (June 1991). See the "COPYING" file distributed with this
6  * software for more info.
7  */
8 
9 /* The low level driver for the WaveFront ICS2115 MIDI interface(s)
10  *
11  * Note that there is also an MPU-401 emulation (actually, a UART-401
12  * emulation) on the CS4232 on the Tropez and Tropez Plus. This code
13  * has nothing to do with that interface at all.
14  *
15  * The interface is essentially just a UART-401, but is has the
16  * interesting property of supporting what Turtle Beach called
17  * "Virtual MIDI" mode. In this mode, there are effectively *two*
18  * MIDI buses accessible via the interface, one that is routed
19  * solely to/from the external WaveFront synthesizer and the other
20  * corresponding to the pin/socket connector used to link external
21  * MIDI devices to the board.
22  *
23  * This driver fully supports this mode, allowing two distinct MIDI
24  * busses to be used completely independently, giving 32 channels of
25  * MIDI routing, 16 to the WaveFront synth and 16 to the external MIDI
26  * bus. The devices are named /dev/snd/midiCnD0 and /dev/snd/midiCnD1,
27  * where `n' is the card number. Note that the device numbers may be
28  * something other than 0 and 1 if the CS4232 UART/MPU-401 interface
29  * is enabled.
30  *
31  * Switching between the two is accomplished externally by the driver
32  * using the two otherwise unused MIDI bytes. See the code for more details.
33  *
34  * NOTE: VIRTUAL MIDI MODE IS ON BY DEFAULT (see lowlevel/isa/wavefront.c)
35  *
36  * The main reason to turn off Virtual MIDI mode is when you want to
37  * tightly couple the WaveFront synth with an external MIDI
38  * device. You won't be able to distinguish the source of any MIDI
39  * data except via SysEx ID, but thats probably OK, since for the most
40  * part, the WaveFront won't be sending any MIDI data at all.
41  *
42  * The main reason to turn on Virtual MIDI Mode is to provide two
43  * completely independent 16-channel MIDI buses, one to the
44  * WaveFront and one to any external MIDI devices. Given the 32
45  * voice nature of the WaveFront, its pretty easy to find a use
46  * for all 16 channels driving just that synth.
47  *
48  */
49 
50 #include <linux/io.h>
51 #include <linux/init.h>
52 #include <linux/time.h>
53 #include <linux/wait.h>
54 #include <sound/core.h>
55 #include <sound/snd_wavefront.h>
56 
57 static inline int
58 wf_mpu_status (snd_wavefront_midi_t *midi)
59 
60 {
61 	return inb (midi->mpu_status_port);
62 }
63 
64 static inline int
65 input_avail (snd_wavefront_midi_t *midi)
66 
67 {
68 	return !(wf_mpu_status(midi) & INPUT_AVAIL);
69 }
70 
71 static inline int
72 output_ready (snd_wavefront_midi_t *midi)
73 
74 {
75 	return !(wf_mpu_status(midi) & OUTPUT_READY);
76 }
77 
78 static inline int
79 read_data (snd_wavefront_midi_t *midi)
80 
81 {
82 	return inb (midi->mpu_data_port);
83 }
84 
85 static inline void
86 write_data (snd_wavefront_midi_t *midi, unsigned char byte)
87 
88 {
89 	outb (byte, midi->mpu_data_port);
90 }
91 
92 static snd_wavefront_midi_t *
93 get_wavefront_midi (struct snd_rawmidi_substream *substream)
94 
95 {
96 	struct snd_card *card;
97 	snd_wavefront_card_t *acard;
98 
99 	if (substream == NULL || substream->rmidi == NULL)
100 	        return NULL;
101 
102 	card = substream->rmidi->card;
103 
104 	if (card == NULL)
105 	        return NULL;
106 
107 	if (card->private_data == NULL)
108  	        return NULL;
109 
110 	acard = card->private_data;
111 
112 	return &acard->wavefront.midi;
113 }
114 
115 static void snd_wavefront_midi_output_write(snd_wavefront_card_t *card)
116 {
117 	snd_wavefront_midi_t *midi = &card->wavefront.midi;
118 	snd_wavefront_mpu_id  mpu;
119 	unsigned long flags;
120 	unsigned char midi_byte;
121 	int max = 256, mask = 1;
122 	int timeout;
123 
124 	/* Its not OK to try to change the status of "virtuality" of
125 	   the MIDI interface while we're outputting stuff.  See
126 	   snd_wavefront_midi_{enable,disable}_virtual () for the
127 	   other half of this.
128 
129 	   The first loop attempts to flush any data from the
130 	   current output device, and then the second
131 	   emits the switch byte (if necessary), and starts
132 	   outputting data for the output device currently in use.
133 	*/
134 
135 	if (midi->substream_output[midi->output_mpu] == NULL) {
136 		goto __second;
137 	}
138 
139 	while (max > 0) {
140 
141 		/* XXX fix me - no hard timing loops allowed! */
142 
143 		for (timeout = 30000; timeout > 0; timeout--) {
144 			if (output_ready (midi))
145 				break;
146 		}
147 
148 		spin_lock_irqsave (&midi->virtual, flags);
149 		if ((midi->mode[midi->output_mpu] & MPU401_MODE_OUTPUT) == 0) {
150 			spin_unlock_irqrestore (&midi->virtual, flags);
151 			goto __second;
152 		}
153 		if (output_ready (midi)) {
154 			if (snd_rawmidi_transmit(midi->substream_output[midi->output_mpu], &midi_byte, 1) == 1) {
155 				if (!midi->isvirtual ||
156 					(midi_byte != WF_INTERNAL_SWITCH &&
157 					 midi_byte != WF_EXTERNAL_SWITCH))
158 					write_data(midi, midi_byte);
159 				max--;
160 			} else {
161 				if (midi->istimer) {
162 					if (--midi->istimer <= 0)
163 						del_timer(&midi->timer);
164 				}
165 				midi->mode[midi->output_mpu] &= ~MPU401_MODE_OUTPUT_TRIGGER;
166 				spin_unlock_irqrestore (&midi->virtual, flags);
167 				goto __second;
168 			}
169 		} else {
170 			spin_unlock_irqrestore (&midi->virtual, flags);
171 			return;
172 		}
173 		spin_unlock_irqrestore (&midi->virtual, flags);
174 	}
175 
176       __second:
177 
178 	if (midi->substream_output[!midi->output_mpu] == NULL) {
179 		return;
180 	}
181 
182 	while (max > 0) {
183 
184 		/* XXX fix me - no hard timing loops allowed! */
185 
186 		for (timeout = 30000; timeout > 0; timeout--) {
187 			if (output_ready (midi))
188 				break;
189 		}
190 
191 		spin_lock_irqsave (&midi->virtual, flags);
192 		if (!midi->isvirtual)
193 			mask = 0;
194 		mpu = midi->output_mpu ^ mask;
195 		mask = 0;	/* don't invert the value from now */
196 		if ((midi->mode[mpu] & MPU401_MODE_OUTPUT) == 0) {
197 			spin_unlock_irqrestore (&midi->virtual, flags);
198 			return;
199 		}
200 		if (snd_rawmidi_transmit_empty(midi->substream_output[mpu]))
201 			goto __timer;
202 		if (output_ready (midi)) {
203 			if (mpu != midi->output_mpu) {
204 				write_data(midi, mpu == internal_mpu ?
205 							WF_INTERNAL_SWITCH :
206 							WF_EXTERNAL_SWITCH);
207 				midi->output_mpu = mpu;
208 			} else if (snd_rawmidi_transmit(midi->substream_output[mpu], &midi_byte, 1) == 1) {
209 				if (!midi->isvirtual ||
210 					(midi_byte != WF_INTERNAL_SWITCH &&
211 					 midi_byte != WF_EXTERNAL_SWITCH))
212 					write_data(midi, midi_byte);
213 				max--;
214 			} else {
215 			      __timer:
216 				if (midi->istimer) {
217 					if (--midi->istimer <= 0)
218 						del_timer(&midi->timer);
219 				}
220 				midi->mode[mpu] &= ~MPU401_MODE_OUTPUT_TRIGGER;
221 				spin_unlock_irqrestore (&midi->virtual, flags);
222 				return;
223 			}
224 		} else {
225 			spin_unlock_irqrestore (&midi->virtual, flags);
226 			return;
227 		}
228 		spin_unlock_irqrestore (&midi->virtual, flags);
229 	}
230 }
231 
232 static int snd_wavefront_midi_input_open(struct snd_rawmidi_substream *substream)
233 {
234 	unsigned long flags;
235 	snd_wavefront_midi_t *midi;
236 	snd_wavefront_mpu_id mpu;
237 
238 	if (snd_BUG_ON(!substream || !substream->rmidi))
239 		return -ENXIO;
240 	if (snd_BUG_ON(!substream->rmidi->private_data))
241 		return -ENXIO;
242 
243 	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
244 
245 	if ((midi = get_wavefront_midi (substream)) == NULL)
246 	        return -EIO;
247 
248 	spin_lock_irqsave (&midi->open, flags);
249 	midi->mode[mpu] |= MPU401_MODE_INPUT;
250 	midi->substream_input[mpu] = substream;
251 	spin_unlock_irqrestore (&midi->open, flags);
252 
253 	return 0;
254 }
255 
256 static int snd_wavefront_midi_output_open(struct snd_rawmidi_substream *substream)
257 {
258 	unsigned long flags;
259 	snd_wavefront_midi_t *midi;
260 	snd_wavefront_mpu_id mpu;
261 
262 	if (snd_BUG_ON(!substream || !substream->rmidi))
263 		return -ENXIO;
264 	if (snd_BUG_ON(!substream->rmidi->private_data))
265 		return -ENXIO;
266 
267 	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
268 
269 	if ((midi = get_wavefront_midi (substream)) == NULL)
270 	        return -EIO;
271 
272 	spin_lock_irqsave (&midi->open, flags);
273 	midi->mode[mpu] |= MPU401_MODE_OUTPUT;
274 	midi->substream_output[mpu] = substream;
275 	spin_unlock_irqrestore (&midi->open, flags);
276 
277 	return 0;
278 }
279 
280 static int snd_wavefront_midi_input_close(struct snd_rawmidi_substream *substream)
281 {
282 	unsigned long flags;
283 	snd_wavefront_midi_t *midi;
284 	snd_wavefront_mpu_id mpu;
285 
286 	if (snd_BUG_ON(!substream || !substream->rmidi))
287 		return -ENXIO;
288 	if (snd_BUG_ON(!substream->rmidi->private_data))
289 		return -ENXIO;
290 
291 	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
292 
293 	if ((midi = get_wavefront_midi (substream)) == NULL)
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 
303 static 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 	if ((midi = get_wavefront_midi (substream)) == NULL)
317 	        return -EIO;
318 
319 	spin_lock_irqsave (&midi->open, flags);
320 	midi->mode[mpu] &= ~MPU401_MODE_OUTPUT;
321 	spin_unlock_irqrestore (&midi->open, flags);
322 	return 0;
323 }
324 
325 static void snd_wavefront_midi_input_trigger(struct snd_rawmidi_substream *substream, int up)
326 {
327 	unsigned long flags;
328 	snd_wavefront_midi_t *midi;
329 	snd_wavefront_mpu_id mpu;
330 
331 	if (substream == NULL || substream->rmidi == NULL)
332 	        return;
333 
334 	if (substream->rmidi->private_data == NULL)
335 	        return;
336 
337 	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
338 
339 	if ((midi = get_wavefront_midi (substream)) == NULL) {
340 		return;
341 	}
342 
343 	spin_lock_irqsave (&midi->virtual, flags);
344 	if (up) {
345 		midi->mode[mpu] |= MPU401_MODE_INPUT_TRIGGER;
346 	} else {
347 		midi->mode[mpu] &= ~MPU401_MODE_INPUT_TRIGGER;
348 	}
349 	spin_unlock_irqrestore (&midi->virtual, flags);
350 }
351 
352 static void snd_wavefront_midi_output_timer(unsigned long data)
353 {
354 	snd_wavefront_card_t *card = (snd_wavefront_card_t *)data;
355 	snd_wavefront_midi_t *midi = &card->wavefront.midi;
356 	unsigned long flags;
357 
358 	spin_lock_irqsave (&midi->virtual, flags);
359 	mod_timer(&midi->timer, 1 + jiffies);
360 	spin_unlock_irqrestore (&midi->virtual, flags);
361 	snd_wavefront_midi_output_write(card);
362 }
363 
364 static void snd_wavefront_midi_output_trigger(struct snd_rawmidi_substream *substream, int up)
365 {
366 	unsigned long flags;
367 	snd_wavefront_midi_t *midi;
368 	snd_wavefront_mpu_id mpu;
369 
370 	if (substream == NULL || substream->rmidi == NULL)
371 	        return;
372 
373 	if (substream->rmidi->private_data == NULL)
374 	        return;
375 
376 	mpu = *((snd_wavefront_mpu_id *) substream->rmidi->private_data);
377 
378 	if ((midi = get_wavefront_midi (substream)) == NULL) {
379 		return;
380 	}
381 
382 	spin_lock_irqsave (&midi->virtual, flags);
383 	if (up) {
384 		if ((midi->mode[mpu] & MPU401_MODE_OUTPUT_TRIGGER) == 0) {
385 			if (!midi->istimer) {
386 				setup_timer(&midi->timer,
387 					    snd_wavefront_midi_output_timer,
388 					    (unsigned long) substream->rmidi->card->private_data);
389 				mod_timer(&midi->timer, 1 + jiffies);
390 			}
391 			midi->istimer++;
392 			midi->mode[mpu] |= MPU401_MODE_OUTPUT_TRIGGER;
393 		}
394 	} else {
395 		midi->mode[mpu] &= ~MPU401_MODE_OUTPUT_TRIGGER;
396 	}
397 	spin_unlock_irqrestore (&midi->virtual, flags);
398 
399 	if (up)
400 		snd_wavefront_midi_output_write((snd_wavefront_card_t *)substream->rmidi->card->private_data);
401 }
402 
403 void
404 snd_wavefront_midi_interrupt (snd_wavefront_card_t *card)
405 
406 {
407 	unsigned long flags;
408 	snd_wavefront_midi_t *midi;
409 	static struct snd_rawmidi_substream *substream = NULL;
410 	static int mpu = external_mpu;
411 	int max = 128;
412 	unsigned char byte;
413 
414 	midi = &card->wavefront.midi;
415 
416 	if (!input_avail (midi)) { /* not for us */
417 		snd_wavefront_midi_output_write(card);
418 		return;
419 	}
420 
421 	spin_lock_irqsave (&midi->virtual, flags);
422 	while (--max) {
423 
424 		if (input_avail (midi)) {
425 			byte = read_data (midi);
426 
427 			if (midi->isvirtual) {
428 				if (byte == WF_EXTERNAL_SWITCH) {
429 					substream = midi->substream_input[external_mpu];
430 					mpu = external_mpu;
431 				} else if (byte == WF_INTERNAL_SWITCH) {
432 					substream = midi->substream_output[internal_mpu];
433 					mpu = internal_mpu;
434 				} /* else just leave it as it is */
435 			} else {
436 				substream = midi->substream_input[internal_mpu];
437 				mpu = internal_mpu;
438 			}
439 
440 			if (substream == NULL) {
441 				continue;
442 			}
443 
444 			if (midi->mode[mpu] & MPU401_MODE_INPUT_TRIGGER) {
445 				snd_rawmidi_receive(substream, &byte, 1);
446 			}
447 		} else {
448 			break;
449 		}
450 	}
451 	spin_unlock_irqrestore (&midi->virtual, flags);
452 
453 	snd_wavefront_midi_output_write(card);
454 }
455 
456 void
457 snd_wavefront_midi_enable_virtual (snd_wavefront_card_t *card)
458 
459 {
460 	unsigned long flags;
461 
462 	spin_lock_irqsave (&card->wavefront.midi.virtual, flags);
463 	card->wavefront.midi.isvirtual = 1;
464 	card->wavefront.midi.output_mpu = internal_mpu;
465 	card->wavefront.midi.input_mpu = internal_mpu;
466 	spin_unlock_irqrestore (&card->wavefront.midi.virtual, flags);
467 }
468 
469 void
470 snd_wavefront_midi_disable_virtual (snd_wavefront_card_t *card)
471 
472 {
473 	unsigned long flags;
474 
475 	spin_lock_irqsave (&card->wavefront.midi.virtual, flags);
476 	// snd_wavefront_midi_input_close (card->ics2115_external_rmidi);
477 	// snd_wavefront_midi_output_close (card->ics2115_external_rmidi);
478 	card->wavefront.midi.isvirtual = 0;
479 	spin_unlock_irqrestore (&card->wavefront.midi.virtual, flags);
480 }
481 
482 int
483 snd_wavefront_midi_start (snd_wavefront_card_t *card)
484 
485 {
486 	int ok, i;
487 	unsigned char rbuf[4], wbuf[4];
488 	snd_wavefront_t *dev;
489 	snd_wavefront_midi_t *midi;
490 
491 	dev = &card->wavefront;
492 	midi = &dev->midi;
493 
494 	/* The ICS2115 MPU-401 interface doesn't do anything
495 	   until its set into UART mode.
496 	*/
497 
498 	/* XXX fix me - no hard timing loops allowed! */
499 
500 	for (i = 0; i < 30000 && !output_ready (midi); i++);
501 
502 	if (!output_ready (midi)) {
503 		snd_printk ("MIDI interface not ready for command\n");
504 		return -1;
505 	}
506 
507 	/* Any interrupts received from now on
508 	   are owned by the MIDI side of things.
509 	*/
510 
511 	dev->interrupts_are_midi = 1;
512 
513 	outb (UART_MODE_ON, midi->mpu_command_port);
514 
515 	for (ok = 0, i = 50000; i > 0 && !ok; i--) {
516 		if (input_avail (midi)) {
517 			if (read_data (midi) == MPU_ACK) {
518 				ok = 1;
519 				break;
520 			}
521 		}
522 	}
523 
524 	if (!ok) {
525 		snd_printk ("cannot set UART mode for MIDI interface");
526 		dev->interrupts_are_midi = 0;
527 		return -1;
528 	}
529 
530 	/* Route external MIDI to WaveFront synth (by default) */
531 
532 	if (snd_wavefront_cmd (dev, WFC_MISYNTH_ON, rbuf, wbuf)) {
533 		snd_printk ("can't enable MIDI-IN-2-synth routing.\n");
534 		/* XXX error ? */
535 	}
536 
537 	/* Turn on Virtual MIDI, but first *always* turn it off,
538 	   since otherwise consecutive reloads of the driver will
539 	   never cause the hardware to generate the initial "internal" or
540 	   "external" source bytes in the MIDI data stream. This
541 	   is pretty important, since the internal hardware generally will
542 	   be used to generate none or very little MIDI output, and
543 	   thus the only source of MIDI data is actually external. Without
544 	   the switch bytes, the driver will think it all comes from
545 	   the internal interface. Duh.
546 	*/
547 
548 	if (snd_wavefront_cmd (dev, WFC_VMIDI_OFF, rbuf, wbuf)) {
549 		snd_printk ("virtual MIDI mode not disabled\n");
550 		return 0; /* We're OK, but missing the external MIDI dev */
551 	}
552 
553 	snd_wavefront_midi_enable_virtual (card);
554 
555 	if (snd_wavefront_cmd (dev, WFC_VMIDI_ON, rbuf, wbuf)) {
556 		snd_printk ("cannot enable virtual MIDI mode.\n");
557 		snd_wavefront_midi_disable_virtual (card);
558 	}
559 	return 0;
560 }
561 
562 const struct snd_rawmidi_ops snd_wavefront_midi_output =
563 {
564 	.open =		snd_wavefront_midi_output_open,
565 	.close =	snd_wavefront_midi_output_close,
566 	.trigger =	snd_wavefront_midi_output_trigger,
567 };
568 
569 const struct snd_rawmidi_ops snd_wavefront_midi_input =
570 {
571 	.open =		snd_wavefront_midi_input_open,
572 	.close =	snd_wavefront_midi_input_close,
573 	.trigger =	snd_wavefront_midi_input_trigger,
574 };
575 
576