xref: /openbmc/linux/sound/drivers/mpu401/mpu401_uart.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2) 
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(mpu401_t * mpu);
47 static void snd_mpu401_uart_output_write(mpu401_t * 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(mpu401_t *mpu, unsigned char data, unsigned long addr)
62 {
63 	outb(data, addr);
64 }
65 
66 static unsigned char mpu401_read_port(mpu401_t *mpu, unsigned long addr)
67 {
68 	return inb(addr);
69 }
70 
71 static void mpu401_write_mmio(mpu401_t *mpu, unsigned char data, unsigned long addr)
72 {
73 	writeb(data, (void __iomem *)addr);
74 }
75 
76 static unsigned char mpu401_read_mmio(mpu401_t *mpu, unsigned long addr)
77 {
78 	return readb((void __iomem *)addr);
79 }
80 /*  */
81 
82 static void snd_mpu401_uart_clear_rx(mpu401_t *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(mpu401_t *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 	mpu401_t *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 	mpu401_t *mpu = (mpu401_t *)data;
136 
137 	spin_lock(&mpu->timer_lock);
138 	/*mpu->mode |= MPU401_MODE_TIMER;*/
139 	mpu->timer.expires = 1 + jiffies;
140 	add_timer(&mpu->timer);
141 	spin_unlock(&mpu->timer_lock);
142 	if (mpu->rmidi)
143 		_snd_mpu401_uart_interrupt(mpu);
144 }
145 
146 /*
147  * initialize the timer callback if not programmed yet
148  */
149 static void snd_mpu401_uart_add_timer (mpu401_t *mpu, int input)
150 {
151 	unsigned long flags;
152 
153 	spin_lock_irqsave (&mpu->timer_lock, flags);
154 	if (mpu->timer_invoked == 0) {
155 		init_timer(&mpu->timer);
156 		mpu->timer.data = (unsigned long)mpu;
157 		mpu->timer.function = snd_mpu401_uart_timer;
158 		mpu->timer.expires = 1 + jiffies;
159 		add_timer(&mpu->timer);
160 	}
161 	mpu->timer_invoked |= input ? MPU401_MODE_INPUT_TIMER : MPU401_MODE_OUTPUT_TIMER;
162 	spin_unlock_irqrestore (&mpu->timer_lock, flags);
163 }
164 
165 /*
166  * remove the timer callback if still active
167  */
168 static void snd_mpu401_uart_remove_timer (mpu401_t *mpu, int input)
169 {
170 	unsigned long flags;
171 
172 	spin_lock_irqsave (&mpu->timer_lock, flags);
173 	if (mpu->timer_invoked) {
174 		mpu->timer_invoked &= input ? ~MPU401_MODE_INPUT_TIMER : ~MPU401_MODE_OUTPUT_TIMER;
175 		if (! mpu->timer_invoked)
176 			del_timer(&mpu->timer);
177 	}
178 	spin_unlock_irqrestore (&mpu->timer_lock, flags);
179 }
180 
181 /*
182 
183  */
184 
185 static void snd_mpu401_uart_cmd(mpu401_t * mpu, unsigned char cmd, int ack)
186 {
187 	unsigned long flags;
188 	int timeout, ok;
189 
190 	spin_lock_irqsave(&mpu->input_lock, flags);
191 	if (mpu->hardware != MPU401_HW_TRID4DWAVE) {
192 		mpu->write(mpu, 0x00, MPU401D(mpu));
193 		/*snd_mpu401_uart_clear_rx(mpu);*/
194 	}
195 	/* ok. standard MPU-401 initialization */
196 	if (mpu->hardware != MPU401_HW_SB) {
197 		for (timeout = 1000; timeout > 0 && !snd_mpu401_output_ready(mpu); timeout--)
198 			udelay(10);
199 #ifdef CONFIG_SND_DEBUG
200 		if (!timeout)
201 			snd_printk("cmd: tx timeout (status = 0x%x)\n", mpu->read(mpu, MPU401C(mpu)));
202 #endif
203 	}
204 	mpu->write(mpu, cmd, MPU401C(mpu));
205 	if (ack) {
206 		ok = 0;
207 		timeout = 10000;
208 		while (!ok && timeout-- > 0) {
209 			if (snd_mpu401_input_avail(mpu)) {
210 				if (mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
211 					ok = 1;
212 			}
213 		}
214 		if (!ok && mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
215 			ok = 1;
216 	} else {
217 		ok = 1;
218 	}
219 	spin_unlock_irqrestore(&mpu->input_lock, flags);
220 	if (! ok)
221 		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)));
222 	// snd_printk("cmd: 0x%x at 0x%lx (status = 0x%x, data = 0x%x)\n", cmd, mpu->port, mpu->read(mpu, MPU401C(mpu)), mpu->read(mpu, MPU401D(mpu)));
223 }
224 
225 /*
226  * input/output open/close - protected by open_mutex in rawmidi.c
227  */
228 static int snd_mpu401_uart_input_open(snd_rawmidi_substream_t * substream)
229 {
230 	mpu401_t *mpu;
231 	int err;
232 
233 	mpu = substream->rmidi->private_data;
234 	if (mpu->open_input && (err = mpu->open_input(mpu)) < 0)
235 		return err;
236 	if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode)) {
237 		snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1);
238 		snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 1);
239 	}
240 	mpu->substream_input = substream;
241 	set_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
242 	return 0;
243 }
244 
245 static int snd_mpu401_uart_output_open(snd_rawmidi_substream_t * substream)
246 {
247 	mpu401_t *mpu;
248 	int err;
249 
250 	mpu = substream->rmidi->private_data;
251 	if (mpu->open_output && (err = mpu->open_output(mpu)) < 0)
252 		return err;
253 	if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode)) {
254 		snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1);
255 		snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 1);
256 	}
257 	mpu->substream_output = substream;
258 	set_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
259 	return 0;
260 }
261 
262 static int snd_mpu401_uart_input_close(snd_rawmidi_substream_t * substream)
263 {
264 	mpu401_t *mpu;
265 
266 	mpu = substream->rmidi->private_data;
267 	clear_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
268 	mpu->substream_input = NULL;
269 	if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode))
270 		snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
271 	if (mpu->close_input)
272 		mpu->close_input(mpu);
273 	return 0;
274 }
275 
276 static int snd_mpu401_uart_output_close(snd_rawmidi_substream_t * substream)
277 {
278 	mpu401_t *mpu;
279 
280 	mpu = substream->rmidi->private_data;
281 	clear_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
282 	mpu->substream_output = NULL;
283 	if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
284 		snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
285 	if (mpu->close_output)
286 		mpu->close_output(mpu);
287 	return 0;
288 }
289 
290 /*
291  * trigger input callback
292  */
293 static void snd_mpu401_uart_input_trigger(snd_rawmidi_substream_t * substream, int up)
294 {
295 	unsigned long flags;
296 	mpu401_t *mpu;
297 	int max = 64;
298 
299 	mpu = substream->rmidi->private_data;
300 	if (up) {
301 		if (! test_and_set_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode)) {
302 			/* first time - flush FIFO */
303 			while (max-- > 0)
304 				mpu->read(mpu, MPU401D(mpu));
305 			if (mpu->irq < 0)
306 				snd_mpu401_uart_add_timer(mpu, 1);
307 		}
308 
309 		/* read data in advance */
310 		spin_lock_irqsave(&mpu->input_lock, flags);
311 		snd_mpu401_uart_input_read(mpu);
312 		spin_unlock_irqrestore(&mpu->input_lock, flags);
313 	} else {
314 		if (mpu->irq < 0)
315 			snd_mpu401_uart_remove_timer(mpu, 1);
316 		clear_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
317 	}
318 }
319 
320 /*
321  * transfer input pending data
322  * call with input_lock spinlock held
323  */
324 static void snd_mpu401_uart_input_read(mpu401_t * mpu)
325 {
326 	int max = 128;
327 	unsigned char byte;
328 
329 	while (max-- > 0) {
330 		if (snd_mpu401_input_avail(mpu)) {
331 			byte = mpu->read(mpu, MPU401D(mpu));
332 			if (test_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode))
333 				snd_rawmidi_receive(mpu->substream_input, &byte, 1);
334 		} else {
335 			break; /* input not available */
336 		}
337 	}
338 }
339 
340 /*
341  *  Tx FIFO sizes:
342  *    CS4237B			- 16 bytes
343  *    AudioDrive ES1688         - 12 bytes
344  *    S3 SonicVibes             -  8 bytes
345  *    SoundBlaster AWE 64       -  2 bytes (ugly hardware)
346  */
347 
348 /*
349  * write output pending bytes
350  * call with output_lock spinlock held
351  */
352 static void snd_mpu401_uart_output_write(mpu401_t * mpu)
353 {
354 	unsigned char byte;
355 	int max = 256, timeout;
356 
357 	do {
358 		if (snd_rawmidi_transmit_peek(mpu->substream_output, &byte, 1) == 1) {
359 			for (timeout = 100; timeout > 0; timeout--) {
360 				if (snd_mpu401_output_ready(mpu)) {
361 					mpu->write(mpu, byte, MPU401D(mpu));
362 					snd_rawmidi_transmit_ack(mpu->substream_output, 1);
363 					break;
364 				}
365 			}
366 			if (timeout == 0)
367 				break;	/* Tx FIFO full - try again later */
368 		} else {
369 			snd_mpu401_uart_remove_timer (mpu, 0);
370 			break;	/* no other data - leave the tx loop */
371 		}
372 	} while (--max > 0);
373 }
374 
375 /*
376  * output trigger callback
377  */
378 static void snd_mpu401_uart_output_trigger(snd_rawmidi_substream_t * substream, int up)
379 {
380 	unsigned long flags;
381 	mpu401_t *mpu;
382 
383 	mpu = substream->rmidi->private_data;
384 	if (up) {
385 		set_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
386 
387 		/* try to add the timer at each output trigger,
388 		 * since the output timer might have been removed in
389 		 * snd_mpu401_uart_output_write().
390 		 */
391 		snd_mpu401_uart_add_timer(mpu, 0);
392 
393 		/* output pending data */
394 		spin_lock_irqsave(&mpu->output_lock, flags);
395 		snd_mpu401_uart_output_write(mpu);
396 		spin_unlock_irqrestore(&mpu->output_lock, flags);
397 	} else {
398 		snd_mpu401_uart_remove_timer(mpu, 0);
399 		clear_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
400 	}
401 }
402 
403 /*
404 
405  */
406 
407 static snd_rawmidi_ops_t snd_mpu401_uart_output =
408 {
409 	.open =		snd_mpu401_uart_output_open,
410 	.close =	snd_mpu401_uart_output_close,
411 	.trigger =	snd_mpu401_uart_output_trigger,
412 };
413 
414 static snd_rawmidi_ops_t snd_mpu401_uart_input =
415 {
416 	.open =		snd_mpu401_uart_input_open,
417 	.close =	snd_mpu401_uart_input_close,
418 	.trigger =	snd_mpu401_uart_input_trigger,
419 };
420 
421 static void snd_mpu401_uart_free(snd_rawmidi_t *rmidi)
422 {
423 	mpu401_t *mpu = rmidi->private_data;
424 	if (mpu->irq_flags && mpu->irq >= 0)
425 		free_irq(mpu->irq, (void *) mpu);
426 	if (mpu->res) {
427 		release_resource(mpu->res);
428 		kfree_nocheck(mpu->res);
429 	}
430 	kfree(mpu);
431 }
432 
433 /**
434  * snd_mpu401_uart_new - create an MPU401-UART instance
435  * @card: the card instance
436  * @device: the device index, zero-based
437  * @hardware: the hardware type, MPU401_HW_XXXX
438  * @port: the base address of MPU401 port
439  * @integrated: non-zero if the port was already reserved by the chip
440  * @irq: the irq number, -1 if no interrupt for mpu
441  * @irq_flags: the irq request flags (SA_XXX), 0 if irq was already reserved.
442  * @rrawmidi: the pointer to store the new rawmidi instance
443  *
444  * Creates a new MPU-401 instance.
445  *
446  * Note that the rawmidi instance is returned on the rrawmidi argument,
447  * not the mpu401 instance itself.  To access to the mpu401 instance,
448  * cast from rawmidi->private_data (with mpu401_t magic-cast).
449  *
450  * Returns zero if successful, or a negative error code.
451  */
452 int snd_mpu401_uart_new(snd_card_t * card, int device,
453 			unsigned short hardware,
454 			unsigned long port, int integrated,
455 			int irq, int irq_flags,
456 			snd_rawmidi_t ** rrawmidi)
457 {
458 	mpu401_t *mpu;
459 	snd_rawmidi_t *rmidi;
460 	int err;
461 
462 	if (rrawmidi)
463 		*rrawmidi = NULL;
464 	if ((err = snd_rawmidi_new(card, "MPU-401U", device, 1, 1, &rmidi)) < 0)
465 		return err;
466 	mpu = kcalloc(1, sizeof(*mpu), GFP_KERNEL);
467 	if (mpu == NULL) {
468 		snd_device_free(card, rmidi);
469 		return -ENOMEM;
470 	}
471 	rmidi->private_data = mpu;
472 	rmidi->private_free = snd_mpu401_uart_free;
473 	spin_lock_init(&mpu->input_lock);
474 	spin_lock_init(&mpu->output_lock);
475 	spin_lock_init(&mpu->timer_lock);
476 	mpu->hardware = hardware;
477 	if (!integrated) {
478 		int res_size = hardware == MPU401_HW_PC98II ? 4 : 2;
479 		if ((mpu->res = request_region(port, res_size, "MPU401 UART")) == NULL) {
480 			snd_printk(KERN_ERR "mpu401_uart: unable to grab port 0x%lx size %d\n", port, res_size);
481 			snd_device_free(card, rmidi);
482 			return -EBUSY;
483 		}
484 	}
485 	switch (hardware) {
486 	case MPU401_HW_AUREAL:
487 		mpu->write = mpu401_write_mmio;
488 		mpu->read = mpu401_read_mmio;
489 		break;
490 	default:
491 		mpu->write = mpu401_write_port;
492 		mpu->read = mpu401_read_port;
493 		break;
494 	}
495 	mpu->port = port;
496 	if (hardware == MPU401_HW_PC98II)
497 		mpu->cport = port + 2;
498 	else
499 		mpu->cport = port + 1;
500 	if (irq >= 0 && irq_flags) {
501 		if (request_irq(irq, snd_mpu401_uart_interrupt, irq_flags, "MPU401 UART", (void *) mpu)) {
502 			snd_printk(KERN_ERR "mpu401_uart: unable to grab IRQ %d\n", irq);
503 			snd_device_free(card, rmidi);
504 			return -EBUSY;
505 		}
506 	}
507 	mpu->irq = irq;
508 	mpu->irq_flags = irq_flags;
509 	if (card->shortname[0])
510 		snprintf(rmidi->name, sizeof(rmidi->name), "%s MIDI", card->shortname);
511 	else
512 		sprintf(rmidi->name, "MPU-401 MIDI %d-%d", card->number, device);
513 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_mpu401_uart_output);
514 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_mpu401_uart_input);
515 	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT |
516 	                     SNDRV_RAWMIDI_INFO_INPUT |
517 	                     SNDRV_RAWMIDI_INFO_DUPLEX;
518 	mpu->rmidi = rmidi;
519 	if (rrawmidi)
520 		*rrawmidi = rmidi;
521 	return 0;
522 }
523 
524 EXPORT_SYMBOL(snd_mpu401_uart_interrupt);
525 EXPORT_SYMBOL(snd_mpu401_uart_new);
526 
527 /*
528  *  INIT part
529  */
530 
531 static int __init alsa_mpu401_uart_init(void)
532 {
533 	return 0;
534 }
535 
536 static void __exit alsa_mpu401_uart_exit(void)
537 {
538 }
539 
540 module_init(alsa_mpu401_uart_init)
541 module_exit(alsa_mpu401_uart_exit)
542