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 <asm/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 	midi->timer.expires = 1 + jiffies;
360 	add_timer(&midi->timer);
361 	spin_unlock_irqrestore (&midi->virtual, flags);
362 	snd_wavefront_midi_output_write(card);
363 }
364 
365 static 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 	if ((midi = get_wavefront_midi (substream)) == NULL) {
380 		return;
381 	}
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 				init_timer(&midi->timer);
388 				midi->timer.function = snd_wavefront_midi_output_timer;
389 				midi->timer.data = (unsigned long) substream->rmidi->card->private_data;
390 				midi->timer.expires = 1 + jiffies;
391 				add_timer(&midi->timer);
392 			}
393 			midi->istimer++;
394 			midi->mode[mpu] |= MPU401_MODE_OUTPUT_TRIGGER;
395 		}
396 	} else {
397 		midi->mode[mpu] &= ~MPU401_MODE_OUTPUT_TRIGGER;
398 	}
399 	spin_unlock_irqrestore (&midi->virtual, flags);
400 
401 	if (up)
402 		snd_wavefront_midi_output_write((snd_wavefront_card_t *)substream->rmidi->card->private_data);
403 }
404 
405 void
406 snd_wavefront_midi_interrupt (snd_wavefront_card_t *card)
407 
408 {
409 	unsigned long flags;
410 	snd_wavefront_midi_t *midi;
411 	static struct snd_rawmidi_substream *substream = NULL;
412 	static int mpu = external_mpu;
413 	int max = 128;
414 	unsigned char byte;
415 
416 	midi = &card->wavefront.midi;
417 
418 	if (!input_avail (midi)) { /* not for us */
419 		snd_wavefront_midi_output_write(card);
420 		return;
421 	}
422 
423 	spin_lock_irqsave (&midi->virtual, flags);
424 	while (--max) {
425 
426 		if (input_avail (midi)) {
427 			byte = read_data (midi);
428 
429 			if (midi->isvirtual) {
430 				if (byte == WF_EXTERNAL_SWITCH) {
431 					substream = midi->substream_input[external_mpu];
432 					mpu = external_mpu;
433 				} else if (byte == WF_INTERNAL_SWITCH) {
434 					substream = midi->substream_output[internal_mpu];
435 					mpu = internal_mpu;
436 				} /* else just leave it as it is */
437 			} else {
438 				substream = midi->substream_input[internal_mpu];
439 				mpu = internal_mpu;
440 			}
441 
442 			if (substream == NULL) {
443 				continue;
444 			}
445 
446 			if (midi->mode[mpu] & MPU401_MODE_INPUT_TRIGGER) {
447 				snd_rawmidi_receive(substream, &byte, 1);
448 			}
449 		} else {
450 			break;
451 		}
452 	}
453 	spin_unlock_irqrestore (&midi->virtual, flags);
454 
455 	snd_wavefront_midi_output_write(card);
456 }
457 
458 void
459 snd_wavefront_midi_enable_virtual (snd_wavefront_card_t *card)
460 
461 {
462 	unsigned long flags;
463 
464 	spin_lock_irqsave (&card->wavefront.midi.virtual, flags);
465 	card->wavefront.midi.isvirtual = 1;
466 	card->wavefront.midi.output_mpu = internal_mpu;
467 	card->wavefront.midi.input_mpu = internal_mpu;
468 	spin_unlock_irqrestore (&card->wavefront.midi.virtual, flags);
469 }
470 
471 void
472 snd_wavefront_midi_disable_virtual (snd_wavefront_card_t *card)
473 
474 {
475 	unsigned long flags;
476 
477 	spin_lock_irqsave (&card->wavefront.midi.virtual, flags);
478 	// snd_wavefront_midi_input_close (card->ics2115_external_rmidi);
479 	// snd_wavefront_midi_output_close (card->ics2115_external_rmidi);
480 	card->wavefront.midi.isvirtual = 0;
481 	spin_unlock_irqrestore (&card->wavefront.midi.virtual, flags);
482 }
483 
484 int
485 snd_wavefront_midi_start (snd_wavefront_card_t *card)
486 
487 {
488 	int ok, i;
489 	unsigned char rbuf[4], wbuf[4];
490 	snd_wavefront_t *dev;
491 	snd_wavefront_midi_t *midi;
492 
493 	dev = &card->wavefront;
494 	midi = &dev->midi;
495 
496 	/* The ICS2115 MPU-401 interface doesn't do anything
497 	   until its set into UART mode.
498 	*/
499 
500 	/* XXX fix me - no hard timing loops allowed! */
501 
502 	for (i = 0; i < 30000 && !output_ready (midi); i++);
503 
504 	if (!output_ready (midi)) {
505 		snd_printk ("MIDI interface not ready for command\n");
506 		return -1;
507 	}
508 
509 	/* Any interrupts received from now on
510 	   are owned by the MIDI side of things.
511 	*/
512 
513 	dev->interrupts_are_midi = 1;
514 
515 	outb (UART_MODE_ON, midi->mpu_command_port);
516 
517 	for (ok = 0, i = 50000; i > 0 && !ok; i--) {
518 		if (input_avail (midi)) {
519 			if (read_data (midi) == MPU_ACK) {
520 				ok = 1;
521 				break;
522 			}
523 		}
524 	}
525 
526 	if (!ok) {
527 		snd_printk ("cannot set UART mode for MIDI interface");
528 		dev->interrupts_are_midi = 0;
529 		return -1;
530 	}
531 
532 	/* Route external MIDI to WaveFront synth (by default) */
533 
534 	if (snd_wavefront_cmd (dev, WFC_MISYNTH_ON, rbuf, wbuf)) {
535 		snd_printk ("can't enable MIDI-IN-2-synth routing.\n");
536 		/* XXX error ? */
537 	}
538 
539 	/* Turn on Virtual MIDI, but first *always* turn it off,
540 	   since otherwise consecutive reloads of the driver will
541 	   never cause the hardware to generate the initial "internal" or
542 	   "external" source bytes in the MIDI data stream. This
543 	   is pretty important, since the internal hardware generally will
544 	   be used to generate none or very little MIDI output, and
545 	   thus the only source of MIDI data is actually external. Without
546 	   the switch bytes, the driver will think it all comes from
547 	   the internal interface. Duh.
548 	*/
549 
550 	if (snd_wavefront_cmd (dev, WFC_VMIDI_OFF, rbuf, wbuf)) {
551 		snd_printk ("virtual MIDI mode not disabled\n");
552 		return 0; /* We're OK, but missing the external MIDI dev */
553 	}
554 
555 	snd_wavefront_midi_enable_virtual (card);
556 
557 	if (snd_wavefront_cmd (dev, WFC_VMIDI_ON, rbuf, wbuf)) {
558 		snd_printk ("cannot enable virtual MIDI mode.\n");
559 		snd_wavefront_midi_disable_virtual (card);
560 	}
561 	return 0;
562 }
563 
564 struct snd_rawmidi_ops snd_wavefront_midi_output =
565 {
566 	.open =		snd_wavefront_midi_output_open,
567 	.close =	snd_wavefront_midi_output_close,
568 	.trigger =	snd_wavefront_midi_output_trigger,
569 };
570 
571 struct snd_rawmidi_ops snd_wavefront_midi_input =
572 {
573 	.open =		snd_wavefront_midi_input_open,
574 	.close =	snd_wavefront_midi_input_close,
575 	.trigger =	snd_wavefront_midi_input_trigger,
576 };
577 
578