1 /*
2  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
3  *  Routines for control of MPU-401 in UART mode
4  *
5  *  MPU-401 supports UART mode which is not capable generate transmit
6  *  interrupts thus output is done via polling. Also, if irq < 0, then
7  *  input is done also via polling. Do not expect good performance.
8  *
9  *
10  *   This program is free software; you can redistribute it and/or modify
11  *   it under the terms of the GNU General Public License as published by
12  *   the Free Software Foundation; either version 2 of the License, or
13  *   (at your option) any later version.
14  *
15  *   This program is distributed in the hope that it will be useful,
16  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
17  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  *   GNU General Public License for more details.
19  *
20  *   You should have received a copy of the GNU General Public License
21  *   along with this program; if not, write to the Free Software
22  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
23  *
24  *   13-03-2003:
25  *      Added support for different kind of hardware I/O. Build in choices
26  *      are port and mmio. For other kind of I/O, set mpu->read and
27  *      mpu->write to your own I/O functions.
28  *
29  */
30 
31 #include <sound/driver.h>
32 #include <asm/io.h>
33 #include <linux/delay.h>
34 #include <linux/init.h>
35 #include <linux/slab.h>
36 #include <linux/ioport.h>
37 #include <linux/interrupt.h>
38 #include <linux/errno.h>
39 #include <sound/core.h>
40 #include <sound/mpu401.h>
41 
42 MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>");
43 MODULE_DESCRIPTION("Routines for control of MPU-401 in UART mode");
44 MODULE_LICENSE("GPL");
45 
46 static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu);
47 static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu);
48 
49 /*
50 
51  */
52 
53 #define snd_mpu401_input_avail(mpu)	(!(mpu->read(mpu, MPU401C(mpu)) & 0x80))
54 #define snd_mpu401_output_ready(mpu)	(!(mpu->read(mpu, MPU401C(mpu)) & 0x40))
55 
56 #define MPU401_RESET		0xff
57 #define MPU401_ENTER_UART	0x3f
58 #define MPU401_ACK		0xfe
59 
60 /* Build in lowlevel io */
61 static void mpu401_write_port(struct snd_mpu401 *mpu, unsigned char data, unsigned long addr)
62 {
63 	outb(data, addr);
64 }
65 
66 static unsigned char mpu401_read_port(struct snd_mpu401 *mpu, unsigned long addr)
67 {
68 	return inb(addr);
69 }
70 
71 static void mpu401_write_mmio(struct snd_mpu401 *mpu, unsigned char data, unsigned long addr)
72 {
73 	writeb(data, (void __iomem *)addr);
74 }
75 
76 static unsigned char mpu401_read_mmio(struct snd_mpu401 *mpu, unsigned long addr)
77 {
78 	return readb((void __iomem *)addr);
79 }
80 /*  */
81 
82 static void snd_mpu401_uart_clear_rx(struct snd_mpu401 *mpu)
83 {
84 	int timeout = 100000;
85 	for (; timeout > 0 && snd_mpu401_input_avail(mpu); timeout--)
86 		mpu->read(mpu, MPU401D(mpu));
87 #ifdef CONFIG_SND_DEBUG
88 	if (timeout <= 0)
89 		snd_printk("cmd: clear rx timeout (status = 0x%x)\n", mpu->read(mpu, MPU401C(mpu)));
90 #endif
91 }
92 
93 static void _snd_mpu401_uart_interrupt(struct snd_mpu401 *mpu)
94 {
95 	spin_lock(&mpu->input_lock);
96 	if (test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode)) {
97 		snd_mpu401_uart_input_read(mpu);
98 	} else {
99 		snd_mpu401_uart_clear_rx(mpu);
100 	}
101 	spin_unlock(&mpu->input_lock);
102  	/* ok. for better Tx performance try do some output when input is done */
103 	if (test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode) &&
104 	    test_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode)) {
105 		spin_lock(&mpu->output_lock);
106 		snd_mpu401_uart_output_write(mpu);
107 		spin_unlock(&mpu->output_lock);
108 	}
109 }
110 
111 /**
112  * snd_mpu401_uart_interrupt - generic MPU401-UART interrupt handler
113  * @irq: the irq number
114  * @dev_id: mpu401 instance
115  * @regs: the reigster
116  *
117  * Processes the interrupt for MPU401-UART i/o.
118  */
119 irqreturn_t snd_mpu401_uart_interrupt(int irq, void *dev_id, struct pt_regs *regs)
120 {
121 	struct snd_mpu401 *mpu = dev_id;
122 
123 	if (mpu == NULL)
124 		return IRQ_NONE;
125 	_snd_mpu401_uart_interrupt(mpu);
126 	return IRQ_HANDLED;
127 }
128 
129 /*
130  * timer callback
131  * reprogram the timer and call the interrupt job
132  */
133 static void snd_mpu401_uart_timer(unsigned long data)
134 {
135 	struct snd_mpu401 *mpu = (struct snd_mpu401 *)data;
136 	unsigned long flags;
137 
138 	spin_lock_irqsave(&mpu->timer_lock, flags);
139 	/*mpu->mode |= MPU401_MODE_TIMER;*/
140 	mpu->timer.expires = 1 + jiffies;
141 	add_timer(&mpu->timer);
142 	spin_unlock_irqrestore(&mpu->timer_lock, flags);
143 	if (mpu->rmidi)
144 		_snd_mpu401_uart_interrupt(mpu);
145 }
146 
147 /*
148  * initialize the timer callback if not programmed yet
149  */
150 static void snd_mpu401_uart_add_timer (struct snd_mpu401 *mpu, int input)
151 {
152 	unsigned long flags;
153 
154 	spin_lock_irqsave (&mpu->timer_lock, flags);
155 	if (mpu->timer_invoked == 0) {
156 		init_timer(&mpu->timer);
157 		mpu->timer.data = (unsigned long)mpu;
158 		mpu->timer.function = snd_mpu401_uart_timer;
159 		mpu->timer.expires = 1 + jiffies;
160 		add_timer(&mpu->timer);
161 	}
162 	mpu->timer_invoked |= input ? MPU401_MODE_INPUT_TIMER : MPU401_MODE_OUTPUT_TIMER;
163 	spin_unlock_irqrestore (&mpu->timer_lock, flags);
164 }
165 
166 /*
167  * remove the timer callback if still active
168  */
169 static void snd_mpu401_uart_remove_timer (struct snd_mpu401 *mpu, int input)
170 {
171 	unsigned long flags;
172 
173 	spin_lock_irqsave (&mpu->timer_lock, flags);
174 	if (mpu->timer_invoked) {
175 		mpu->timer_invoked &= input ? ~MPU401_MODE_INPUT_TIMER : ~MPU401_MODE_OUTPUT_TIMER;
176 		if (! mpu->timer_invoked)
177 			del_timer(&mpu->timer);
178 	}
179 	spin_unlock_irqrestore (&mpu->timer_lock, flags);
180 }
181 
182 /*
183 
184  */
185 
186 static int snd_mpu401_uart_cmd(struct snd_mpu401 * mpu, unsigned char cmd,
187 		int ack)
188 {
189 	unsigned long flags;
190 	int timeout, ok;
191 
192 	spin_lock_irqsave(&mpu->input_lock, flags);
193 	if (mpu->hardware != MPU401_HW_TRID4DWAVE) {
194 		mpu->write(mpu, 0x00, MPU401D(mpu));
195 		/*snd_mpu401_uart_clear_rx(mpu);*/
196 	}
197 	/* ok. standard MPU-401 initialization */
198 	if (mpu->hardware != MPU401_HW_SB) {
199 		for (timeout = 1000; timeout > 0 && !snd_mpu401_output_ready(mpu); timeout--)
200 			udelay(10);
201 #ifdef CONFIG_SND_DEBUG
202 		if (!timeout)
203 			snd_printk("cmd: tx timeout (status = 0x%x)\n", mpu->read(mpu, MPU401C(mpu)));
204 #endif
205 	}
206 	mpu->write(mpu, cmd, MPU401C(mpu));
207 	if (ack) {
208 		ok = 0;
209 		timeout = 10000;
210 		while (!ok && timeout-- > 0) {
211 			if (snd_mpu401_input_avail(mpu)) {
212 				if (mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
213 					ok = 1;
214 			}
215 		}
216 		if (!ok && mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
217 			ok = 1;
218 	} else {
219 		ok = 1;
220 	}
221 	spin_unlock_irqrestore(&mpu->input_lock, flags);
222 	if (!ok) {
223 		snd_printk("cmd: 0x%x failed at 0x%lx (status = 0x%x, data = 0x%x)\n", cmd, mpu->port, mpu->read(mpu, MPU401C(mpu)), mpu->read(mpu, MPU401D(mpu)));
224 		return 1;
225 	}
226 	return 0;
227 }
228 
229 /*
230  * input/output open/close - protected by open_mutex in rawmidi.c
231  */
232 static int snd_mpu401_uart_input_open(struct snd_rawmidi_substream *substream)
233 {
234 	struct snd_mpu401 *mpu;
235 	int err;
236 
237 	mpu = substream->rmidi->private_data;
238 	if (mpu->open_input && (err = mpu->open_input(mpu)) < 0)
239 		return err;
240 	if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode)) {
241 		if (snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1))
242 			goto error_out;
243 		if (snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 1))
244 			goto error_out;
245 	}
246 	mpu->substream_input = substream;
247 	set_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
248 	return 0;
249 
250 error_out:
251 	if (mpu->open_input && mpu->close_input)
252 		mpu->close_input(mpu);
253 	return -EIO;
254 }
255 
256 static int snd_mpu401_uart_output_open(struct snd_rawmidi_substream *substream)
257 {
258 	struct snd_mpu401 *mpu;
259 	int err;
260 
261 	mpu = substream->rmidi->private_data;
262 	if (mpu->open_output && (err = mpu->open_output(mpu)) < 0)
263 		return err;
264 	if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode)) {
265 		if (snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1))
266 			goto error_out;
267 		if (snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 1))
268 			goto error_out;
269 	}
270 	mpu->substream_output = substream;
271 	set_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
272 	return 0;
273 
274 error_out:
275 	if (mpu->open_output && mpu->close_output)
276 		mpu->close_output(mpu);
277 	return -EIO;
278 }
279 
280 static int snd_mpu401_uart_input_close(struct snd_rawmidi_substream *substream)
281 {
282 	struct snd_mpu401 *mpu;
283 	int err = 0;
284 
285 	mpu = substream->rmidi->private_data;
286 	clear_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
287 	mpu->substream_input = NULL;
288 	if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode))
289 		err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
290 	if (mpu->close_input)
291 		mpu->close_input(mpu);
292 	if (err)
293 		return -EIO;
294 	return 0;
295 }
296 
297 static int snd_mpu401_uart_output_close(struct snd_rawmidi_substream *substream)
298 {
299 	struct snd_mpu401 *mpu;
300 	int err = 0;
301 
302 	mpu = substream->rmidi->private_data;
303 	clear_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
304 	mpu->substream_output = NULL;
305 	if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
306 		err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
307 	if (mpu->close_output)
308 		mpu->close_output(mpu);
309 	if (err)
310 		return -EIO;
311 	return 0;
312 }
313 
314 /*
315  * trigger input callback
316  */
317 static void snd_mpu401_uart_input_trigger(struct snd_rawmidi_substream *substream, int up)
318 {
319 	unsigned long flags;
320 	struct snd_mpu401 *mpu;
321 	int max = 64;
322 
323 	mpu = substream->rmidi->private_data;
324 	if (up) {
325 		if (! test_and_set_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode)) {
326 			/* first time - flush FIFO */
327 			while (max-- > 0)
328 				mpu->read(mpu, MPU401D(mpu));
329 			if (mpu->irq < 0)
330 				snd_mpu401_uart_add_timer(mpu, 1);
331 		}
332 
333 		/* read data in advance */
334 		spin_lock_irqsave(&mpu->input_lock, flags);
335 		snd_mpu401_uart_input_read(mpu);
336 		spin_unlock_irqrestore(&mpu->input_lock, flags);
337 	} else {
338 		if (mpu->irq < 0)
339 			snd_mpu401_uart_remove_timer(mpu, 1);
340 		clear_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
341 	}
342 
343 }
344 
345 /*
346  * transfer input pending data
347  * call with input_lock spinlock held
348  */
349 static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu)
350 {
351 	int max = 128;
352 	unsigned char byte;
353 
354 	while (max-- > 0) {
355 		if (snd_mpu401_input_avail(mpu)) {
356 			byte = mpu->read(mpu, MPU401D(mpu));
357 			if (test_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode))
358 				snd_rawmidi_receive(mpu->substream_input, &byte, 1);
359 		} else {
360 			break; /* input not available */
361 		}
362 	}
363 }
364 
365 /*
366  *  Tx FIFO sizes:
367  *    CS4237B			- 16 bytes
368  *    AudioDrive ES1688         - 12 bytes
369  *    S3 SonicVibes             -  8 bytes
370  *    SoundBlaster AWE 64       -  2 bytes (ugly hardware)
371  */
372 
373 /*
374  * write output pending bytes
375  * call with output_lock spinlock held
376  */
377 static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu)
378 {
379 	unsigned char byte;
380 	int max = 256, timeout;
381 
382 	do {
383 		if (snd_rawmidi_transmit_peek(mpu->substream_output, &byte, 1) == 1) {
384 			for (timeout = 100; timeout > 0; timeout--) {
385 				if (snd_mpu401_output_ready(mpu)) {
386 					mpu->write(mpu, byte, MPU401D(mpu));
387 					snd_rawmidi_transmit_ack(mpu->substream_output, 1);
388 					break;
389 				}
390 			}
391 			if (timeout == 0)
392 				break;	/* Tx FIFO full - try again later */
393 		} else {
394 			snd_mpu401_uart_remove_timer (mpu, 0);
395 			break;	/* no other data - leave the tx loop */
396 		}
397 	} while (--max > 0);
398 }
399 
400 /*
401  * output trigger callback
402  */
403 static void snd_mpu401_uart_output_trigger(struct snd_rawmidi_substream *substream, int up)
404 {
405 	unsigned long flags;
406 	struct snd_mpu401 *mpu;
407 
408 	mpu = substream->rmidi->private_data;
409 	if (up) {
410 		set_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
411 
412 		/* try to add the timer at each output trigger,
413 		 * since the output timer might have been removed in
414 		 * snd_mpu401_uart_output_write().
415 		 */
416 		snd_mpu401_uart_add_timer(mpu, 0);
417 
418 		/* output pending data */
419 		spin_lock_irqsave(&mpu->output_lock, flags);
420 		snd_mpu401_uart_output_write(mpu);
421 		spin_unlock_irqrestore(&mpu->output_lock, flags);
422 	} else {
423 		snd_mpu401_uart_remove_timer(mpu, 0);
424 		clear_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
425 	}
426 }
427 
428 /*
429 
430  */
431 
432 static struct snd_rawmidi_ops snd_mpu401_uart_output =
433 {
434 	.open =		snd_mpu401_uart_output_open,
435 	.close =	snd_mpu401_uart_output_close,
436 	.trigger =	snd_mpu401_uart_output_trigger,
437 };
438 
439 static struct snd_rawmidi_ops snd_mpu401_uart_input =
440 {
441 	.open =		snd_mpu401_uart_input_open,
442 	.close =	snd_mpu401_uart_input_close,
443 	.trigger =	snd_mpu401_uart_input_trigger,
444 };
445 
446 static void snd_mpu401_uart_free(struct snd_rawmidi *rmidi)
447 {
448 	struct snd_mpu401 *mpu = rmidi->private_data;
449 	if (mpu->irq_flags && mpu->irq >= 0)
450 		free_irq(mpu->irq, (void *) mpu);
451 	release_and_free_resource(mpu->res);
452 	kfree(mpu);
453 }
454 
455 /**
456  * snd_mpu401_uart_new - create an MPU401-UART instance
457  * @card: the card instance
458  * @device: the device index, zero-based
459  * @hardware: the hardware type, MPU401_HW_XXXX
460  * @port: the base address of MPU401 port
461  * @integrated: non-zero if the port was already reserved by the chip
462  * @irq: the irq number, -1 if no interrupt for mpu
463  * @irq_flags: the irq request flags (SA_XXX), 0 if irq was already reserved.
464  * @rrawmidi: the pointer to store the new rawmidi instance
465  *
466  * Creates a new MPU-401 instance.
467  *
468  * Note that the rawmidi instance is returned on the rrawmidi argument,
469  * not the mpu401 instance itself.  To access to the mpu401 instance,
470  * cast from rawmidi->private_data (with struct snd_mpu401 magic-cast).
471  *
472  * Returns zero if successful, or a negative error code.
473  */
474 int snd_mpu401_uart_new(struct snd_card *card, int device,
475 			unsigned short hardware,
476 			unsigned long port, int integrated,
477 			int irq, int irq_flags,
478 			struct snd_rawmidi ** rrawmidi)
479 {
480 	struct snd_mpu401 *mpu;
481 	struct snd_rawmidi *rmidi;
482 	int err;
483 
484 	if (rrawmidi)
485 		*rrawmidi = NULL;
486 	if ((err = snd_rawmidi_new(card, "MPU-401U", device, 1, 1, &rmidi)) < 0)
487 		return err;
488 	mpu = kzalloc(sizeof(*mpu), GFP_KERNEL);
489 	if (mpu == NULL) {
490 		snd_printk(KERN_ERR "mpu401_uart: cannot allocate\n");
491 		snd_device_free(card, rmidi);
492 		return -ENOMEM;
493 	}
494 	rmidi->private_data = mpu;
495 	rmidi->private_free = snd_mpu401_uart_free;
496 	spin_lock_init(&mpu->input_lock);
497 	spin_lock_init(&mpu->output_lock);
498 	spin_lock_init(&mpu->timer_lock);
499 	mpu->hardware = hardware;
500 	if (!integrated) {
501 		int res_size = hardware == MPU401_HW_PC98II ? 4 : 2;
502 		if ((mpu->res = request_region(port, res_size, "MPU401 UART")) == NULL) {
503 			snd_printk(KERN_ERR "mpu401_uart: unable to grab port 0x%lx size %d\n", port, res_size);
504 			snd_device_free(card, rmidi);
505 			return -EBUSY;
506 		}
507 	}
508 	switch (hardware) {
509 	case MPU401_HW_AUREAL:
510 		mpu->write = mpu401_write_mmio;
511 		mpu->read = mpu401_read_mmio;
512 		break;
513 	default:
514 		mpu->write = mpu401_write_port;
515 		mpu->read = mpu401_read_port;
516 		break;
517 	}
518 	mpu->port = port;
519 	if (hardware == MPU401_HW_PC98II)
520 		mpu->cport = port + 2;
521 	else
522 		mpu->cport = port + 1;
523 	if (irq >= 0 && irq_flags) {
524 		if (request_irq(irq, snd_mpu401_uart_interrupt, irq_flags, "MPU401 UART", (void *) mpu)) {
525 			snd_printk(KERN_ERR "mpu401_uart: unable to grab IRQ %d\n", irq);
526 			snd_device_free(card, rmidi);
527 			return -EBUSY;
528 		}
529 	}
530 	mpu->irq = irq;
531 	mpu->irq_flags = irq_flags;
532 	if (card->shortname[0])
533 		snprintf(rmidi->name, sizeof(rmidi->name), "%s MIDI", card->shortname);
534 	else
535 		sprintf(rmidi->name, "MPU-401 MIDI %d-%d", card->number, device);
536 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_mpu401_uart_output);
537 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_mpu401_uart_input);
538 	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT |
539 	                     SNDRV_RAWMIDI_INFO_INPUT |
540 	                     SNDRV_RAWMIDI_INFO_DUPLEX;
541 	mpu->rmidi = rmidi;
542 	if (rrawmidi)
543 		*rrawmidi = rmidi;
544 	return 0;
545 }
546 
547 EXPORT_SYMBOL(snd_mpu401_uart_interrupt);
548 EXPORT_SYMBOL(snd_mpu401_uart_new);
549 
550 /*
551  *  INIT part
552  */
553 
554 static int __init alsa_mpu401_uart_init(void)
555 {
556 	return 0;
557 }
558 
559 static void __exit alsa_mpu401_uart_exit(void)
560 {
561 }
562 
563 module_init(alsa_mpu401_uart_init)
564 module_exit(alsa_mpu401_uart_exit)
565