1/*
2 *  Copyright (c) by Jaroslav Kysela <perex@perex.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. Without interrupt,
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 <linux/io.h>
32#include <linux/delay.h>
33#include <linux/init.h>
34#include <linux/slab.h>
35#include <linux/ioport.h>
36#include <linux/module.h>
37#include <linux/interrupt.h>
38#include <linux/errno.h>
39#include <sound/core.h>
40#include <sound/mpu401.h>
41
42MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
43MODULE_DESCRIPTION("Routines for control of MPU-401 in UART mode");
44MODULE_LICENSE("GPL");
45
46static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu);
47static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu);
48
49/*
50
51 */
52
53#define snd_mpu401_input_avail(mpu) \
54	(!(mpu->read(mpu, MPU401C(mpu)) & MPU401_RX_EMPTY))
55#define snd_mpu401_output_ready(mpu) \
56	(!(mpu->read(mpu, MPU401C(mpu)) & MPU401_TX_FULL))
57
58/* Build in lowlevel io */
59static void mpu401_write_port(struct snd_mpu401 *mpu, unsigned char data,
60			      unsigned long addr)
61{
62	outb(data, addr);
63}
64
65static unsigned char mpu401_read_port(struct snd_mpu401 *mpu,
66				      unsigned long addr)
67{
68	return inb(addr);
69}
70
71static void mpu401_write_mmio(struct snd_mpu401 *mpu, unsigned char data,
72			      unsigned long addr)
73{
74	writeb(data, (void __iomem *)addr);
75}
76
77static unsigned char mpu401_read_mmio(struct snd_mpu401 *mpu,
78				      unsigned long addr)
79{
80	return readb((void __iomem *)addr);
81}
82/*  */
83
84static void snd_mpu401_uart_clear_rx(struct snd_mpu401 *mpu)
85{
86	int timeout = 100000;
87	for (; timeout > 0 && snd_mpu401_input_avail(mpu); timeout--)
88		mpu->read(mpu, MPU401D(mpu));
89#ifdef CONFIG_SND_DEBUG
90	if (timeout <= 0)
91		snd_printk(KERN_ERR "cmd: clear rx timeout (status = 0x%x)\n",
92			   mpu->read(mpu, MPU401C(mpu)));
93#endif
94}
95
96static void uart_interrupt_tx(struct snd_mpu401 *mpu)
97{
98	unsigned long flags;
99
100	if (test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode) &&
101	    test_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode)) {
102		spin_lock_irqsave(&mpu->output_lock, flags);
103		snd_mpu401_uart_output_write(mpu);
104		spin_unlock_irqrestore(&mpu->output_lock, flags);
105	}
106}
107
108static void _snd_mpu401_uart_interrupt(struct snd_mpu401 *mpu)
109{
110	unsigned long flags;
111
112	if (mpu->info_flags & MPU401_INFO_INPUT) {
113		spin_lock_irqsave(&mpu->input_lock, flags);
114		if (test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
115			snd_mpu401_uart_input_read(mpu);
116		else
117			snd_mpu401_uart_clear_rx(mpu);
118		spin_unlock_irqrestore(&mpu->input_lock, flags);
119	}
120	if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
121		/* ok. for better Tx performance try do some output
122		   when input is done */
123		uart_interrupt_tx(mpu);
124}
125
126/**
127 * snd_mpu401_uart_interrupt - generic MPU401-UART interrupt handler
128 * @irq: the irq number
129 * @dev_id: mpu401 instance
130 *
131 * Processes the interrupt for MPU401-UART i/o.
132 *
133 * Return: %IRQ_HANDLED if the interrupt was handled. %IRQ_NONE otherwise.
134 */
135irqreturn_t snd_mpu401_uart_interrupt(int irq, void *dev_id)
136{
137	struct snd_mpu401 *mpu = dev_id;
138
139	if (mpu == NULL)
140		return IRQ_NONE;
141	_snd_mpu401_uart_interrupt(mpu);
142	return IRQ_HANDLED;
143}
144
145EXPORT_SYMBOL(snd_mpu401_uart_interrupt);
146
147/**
148 * snd_mpu401_uart_interrupt_tx - generic MPU401-UART transmit irq handler
149 * @irq: the irq number
150 * @dev_id: mpu401 instance
151 *
152 * Processes the interrupt for MPU401-UART output.
153 *
154 * Return: %IRQ_HANDLED if the interrupt was handled. %IRQ_NONE otherwise.
155 */
156irqreturn_t snd_mpu401_uart_interrupt_tx(int irq, void *dev_id)
157{
158	struct snd_mpu401 *mpu = dev_id;
159
160	if (mpu == NULL)
161		return IRQ_NONE;
162	uart_interrupt_tx(mpu);
163	return IRQ_HANDLED;
164}
165
166EXPORT_SYMBOL(snd_mpu401_uart_interrupt_tx);
167
168/*
169 * timer callback
170 * reprogram the timer and call the interrupt job
171 */
172static void snd_mpu401_uart_timer(unsigned long data)
173{
174	struct snd_mpu401 *mpu = (struct snd_mpu401 *)data;
175	unsigned long flags;
176
177	spin_lock_irqsave(&mpu->timer_lock, flags);
178	/*mpu->mode |= MPU401_MODE_TIMER;*/
179	mod_timer(&mpu->timer,  1 + jiffies);
180	spin_unlock_irqrestore(&mpu->timer_lock, flags);
181	if (mpu->rmidi)
182		_snd_mpu401_uart_interrupt(mpu);
183}
184
185/*
186 * initialize the timer callback if not programmed yet
187 */
188static void snd_mpu401_uart_add_timer (struct snd_mpu401 *mpu, int input)
189{
190	unsigned long flags;
191
192	spin_lock_irqsave (&mpu->timer_lock, flags);
193	if (mpu->timer_invoked == 0) {
194		setup_timer(&mpu->timer, snd_mpu401_uart_timer,
195			    (unsigned long)mpu);
196		mod_timer(&mpu->timer, 1 + jiffies);
197	}
198	mpu->timer_invoked |= input ? MPU401_MODE_INPUT_TIMER :
199		MPU401_MODE_OUTPUT_TIMER;
200	spin_unlock_irqrestore (&mpu->timer_lock, flags);
201}
202
203/*
204 * remove the timer callback if still active
205 */
206static void snd_mpu401_uart_remove_timer (struct snd_mpu401 *mpu, int input)
207{
208	unsigned long flags;
209
210	spin_lock_irqsave (&mpu->timer_lock, flags);
211	if (mpu->timer_invoked) {
212		mpu->timer_invoked &= input ? ~MPU401_MODE_INPUT_TIMER :
213			~MPU401_MODE_OUTPUT_TIMER;
214		if (! mpu->timer_invoked)
215			del_timer(&mpu->timer);
216	}
217	spin_unlock_irqrestore (&mpu->timer_lock, flags);
218}
219
220/*
221 * send a UART command
222 * return zero if successful, non-zero for some errors
223 */
224
225static int snd_mpu401_uart_cmd(struct snd_mpu401 * mpu, unsigned char cmd,
226			       int ack)
227{
228	unsigned long flags;
229	int timeout, ok;
230
231	spin_lock_irqsave(&mpu->input_lock, flags);
232	if (mpu->hardware != MPU401_HW_TRID4DWAVE) {
233		mpu->write(mpu, 0x00, MPU401D(mpu));
234		/*snd_mpu401_uart_clear_rx(mpu);*/
235	}
236	/* ok. standard MPU-401 initialization */
237	if (mpu->hardware != MPU401_HW_SB) {
238		for (timeout = 1000; timeout > 0 &&
239			     !snd_mpu401_output_ready(mpu); timeout--)
240			udelay(10);
241#ifdef CONFIG_SND_DEBUG
242		if (!timeout)
243			snd_printk(KERN_ERR "cmd: tx timeout (status = 0x%x)\n",
244				   mpu->read(mpu, MPU401C(mpu)));
245#endif
246	}
247	mpu->write(mpu, cmd, MPU401C(mpu));
248	if (ack && !(mpu->info_flags & MPU401_INFO_NO_ACK)) {
249		ok = 0;
250		timeout = 10000;
251		while (!ok && timeout-- > 0) {
252			if (snd_mpu401_input_avail(mpu)) {
253				if (mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
254					ok = 1;
255			}
256		}
257		if (!ok && mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
258			ok = 1;
259	} else
260		ok = 1;
261	spin_unlock_irqrestore(&mpu->input_lock, flags);
262	if (!ok) {
263		snd_printk(KERN_ERR "cmd: 0x%x failed at 0x%lx "
264			   "(status = 0x%x, data = 0x%x)\n", cmd, mpu->port,
265			   mpu->read(mpu, MPU401C(mpu)),
266			   mpu->read(mpu, MPU401D(mpu)));
267		return 1;
268	}
269	return 0;
270}
271
272static int snd_mpu401_do_reset(struct snd_mpu401 *mpu)
273{
274	if (snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1))
275		return -EIO;
276	if (snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 0))
277		return -EIO;
278	return 0;
279}
280
281/*
282 * input/output open/close - protected by open_mutex in rawmidi.c
283 */
284static int snd_mpu401_uart_input_open(struct snd_rawmidi_substream *substream)
285{
286	struct snd_mpu401 *mpu;
287	int err;
288
289	mpu = substream->rmidi->private_data;
290	if (mpu->open_input && (err = mpu->open_input(mpu)) < 0)
291		return err;
292	if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode)) {
293		if (snd_mpu401_do_reset(mpu) < 0)
294			goto error_out;
295	}
296	mpu->substream_input = substream;
297	set_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
298	return 0;
299
300error_out:
301	if (mpu->open_input && mpu->close_input)
302		mpu->close_input(mpu);
303	return -EIO;
304}
305
306static int snd_mpu401_uart_output_open(struct snd_rawmidi_substream *substream)
307{
308	struct snd_mpu401 *mpu;
309	int err;
310
311	mpu = substream->rmidi->private_data;
312	if (mpu->open_output && (err = mpu->open_output(mpu)) < 0)
313		return err;
314	if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode)) {
315		if (snd_mpu401_do_reset(mpu) < 0)
316			goto error_out;
317	}
318	mpu->substream_output = substream;
319	set_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
320	return 0;
321
322error_out:
323	if (mpu->open_output && mpu->close_output)
324		mpu->close_output(mpu);
325	return -EIO;
326}
327
328static int snd_mpu401_uart_input_close(struct snd_rawmidi_substream *substream)
329{
330	struct snd_mpu401 *mpu;
331	int err = 0;
332
333	mpu = substream->rmidi->private_data;
334	clear_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
335	mpu->substream_input = NULL;
336	if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode))
337		err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
338	if (mpu->close_input)
339		mpu->close_input(mpu);
340	if (err)
341		return -EIO;
342	return 0;
343}
344
345static int snd_mpu401_uart_output_close(struct snd_rawmidi_substream *substream)
346{
347	struct snd_mpu401 *mpu;
348	int err = 0;
349
350	mpu = substream->rmidi->private_data;
351	clear_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
352	mpu->substream_output = NULL;
353	if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
354		err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
355	if (mpu->close_output)
356		mpu->close_output(mpu);
357	if (err)
358		return -EIO;
359	return 0;
360}
361
362/*
363 * trigger input callback
364 */
365static void
366snd_mpu401_uart_input_trigger(struct snd_rawmidi_substream *substream, int up)
367{
368	unsigned long flags;
369	struct snd_mpu401 *mpu;
370	int max = 64;
371
372	mpu = substream->rmidi->private_data;
373	if (up) {
374		if (! test_and_set_bit(MPU401_MODE_BIT_INPUT_TRIGGER,
375				       &mpu->mode)) {
376			/* first time - flush FIFO */
377			while (max-- > 0)
378				mpu->read(mpu, MPU401D(mpu));
379			if (mpu->info_flags & MPU401_INFO_USE_TIMER)
380				snd_mpu401_uart_add_timer(mpu, 1);
381		}
382
383		/* read data in advance */
384		spin_lock_irqsave(&mpu->input_lock, flags);
385		snd_mpu401_uart_input_read(mpu);
386		spin_unlock_irqrestore(&mpu->input_lock, flags);
387	} else {
388		if (mpu->info_flags & MPU401_INFO_USE_TIMER)
389			snd_mpu401_uart_remove_timer(mpu, 1);
390		clear_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
391	}
392
393}
394
395/*
396 * transfer input pending data
397 * call with input_lock spinlock held
398 */
399static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu)
400{
401	int max = 128;
402	unsigned char byte;
403
404	while (max-- > 0) {
405		if (! snd_mpu401_input_avail(mpu))
406			break; /* input not available */
407		byte = mpu->read(mpu, MPU401D(mpu));
408		if (test_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode))
409			snd_rawmidi_receive(mpu->substream_input, &byte, 1);
410	}
411}
412
413/*
414 *  Tx FIFO sizes:
415 *    CS4237B			- 16 bytes
416 *    AudioDrive ES1688         - 12 bytes
417 *    S3 SonicVibes             -  8 bytes
418 *    SoundBlaster AWE 64       -  2 bytes (ugly hardware)
419 */
420
421/*
422 * write output pending bytes
423 * call with output_lock spinlock held
424 */
425static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu)
426{
427	unsigned char byte;
428	int max = 256;
429
430	do {
431		if (snd_rawmidi_transmit_peek(mpu->substream_output,
432					      &byte, 1) == 1) {
433			/*
434			 * Try twice because there is hardware that insists on
435			 * setting the output busy bit after each write.
436			 */
437			if (!snd_mpu401_output_ready(mpu) &&
438			    !snd_mpu401_output_ready(mpu))
439				break;	/* Tx FIFO full - try again later */
440			mpu->write(mpu, byte, MPU401D(mpu));
441			snd_rawmidi_transmit_ack(mpu->substream_output, 1);
442		} else {
443			snd_mpu401_uart_remove_timer (mpu, 0);
444			break;	/* no other data - leave the tx loop */
445		}
446	} while (--max > 0);
447}
448
449/*
450 * output trigger callback
451 */
452static void
453snd_mpu401_uart_output_trigger(struct snd_rawmidi_substream *substream, int up)
454{
455	unsigned long flags;
456	struct snd_mpu401 *mpu;
457
458	mpu = substream->rmidi->private_data;
459	if (up) {
460		set_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
461
462		/* try to add the timer at each output trigger,
463		 * since the output timer might have been removed in
464		 * snd_mpu401_uart_output_write().
465		 */
466		if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
467			snd_mpu401_uart_add_timer(mpu, 0);
468
469		/* output pending data */
470		spin_lock_irqsave(&mpu->output_lock, flags);
471		snd_mpu401_uart_output_write(mpu);
472		spin_unlock_irqrestore(&mpu->output_lock, flags);
473	} else {
474		if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
475			snd_mpu401_uart_remove_timer(mpu, 0);
476		clear_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
477	}
478}
479
480/*
481
482 */
483
484static struct snd_rawmidi_ops snd_mpu401_uart_output =
485{
486	.open =		snd_mpu401_uart_output_open,
487	.close =	snd_mpu401_uart_output_close,
488	.trigger =	snd_mpu401_uart_output_trigger,
489};
490
491static struct snd_rawmidi_ops snd_mpu401_uart_input =
492{
493	.open =		snd_mpu401_uart_input_open,
494	.close =	snd_mpu401_uart_input_close,
495	.trigger =	snd_mpu401_uart_input_trigger,
496};
497
498static void snd_mpu401_uart_free(struct snd_rawmidi *rmidi)
499{
500	struct snd_mpu401 *mpu = rmidi->private_data;
501	if (mpu->irq >= 0)
502		free_irq(mpu->irq, (void *) mpu);
503	release_and_free_resource(mpu->res);
504	kfree(mpu);
505}
506
507/**
508 * snd_mpu401_uart_new - create an MPU401-UART instance
509 * @card: the card instance
510 * @device: the device index, zero-based
511 * @hardware: the hardware type, MPU401_HW_XXXX
512 * @port: the base address of MPU401 port
513 * @info_flags: bitflags MPU401_INFO_XXX
514 * @irq: the ISA irq number, -1 if not to be allocated
515 * @rrawmidi: the pointer to store the new rawmidi instance
516 *
517 * Creates a new MPU-401 instance.
518 *
519 * Note that the rawmidi instance is returned on the rrawmidi argument,
520 * not the mpu401 instance itself.  To access to the mpu401 instance,
521 * cast from rawmidi->private_data (with struct snd_mpu401 magic-cast).
522 *
523 * Return: Zero if successful, or a negative error code.
524 */
525int snd_mpu401_uart_new(struct snd_card *card, int device,
526			unsigned short hardware,
527			unsigned long port,
528			unsigned int info_flags,
529			int irq,
530			struct snd_rawmidi ** rrawmidi)
531{
532	struct snd_mpu401 *mpu;
533	struct snd_rawmidi *rmidi;
534	int in_enable, out_enable;
535	int err;
536
537	if (rrawmidi)
538		*rrawmidi = NULL;
539	if (! (info_flags & (MPU401_INFO_INPUT | MPU401_INFO_OUTPUT)))
540		info_flags |= MPU401_INFO_INPUT | MPU401_INFO_OUTPUT;
541	in_enable = (info_flags & MPU401_INFO_INPUT) ? 1 : 0;
542	out_enable = (info_flags & MPU401_INFO_OUTPUT) ? 1 : 0;
543	if ((err = snd_rawmidi_new(card, "MPU-401U", device,
544				   out_enable, in_enable, &rmidi)) < 0)
545		return err;
546	mpu = kzalloc(sizeof(*mpu), GFP_KERNEL);
547	if (mpu == NULL) {
548		snd_printk(KERN_ERR "mpu401_uart: cannot allocate\n");
549		snd_device_free(card, rmidi);
550		return -ENOMEM;
551	}
552	rmidi->private_data = mpu;
553	rmidi->private_free = snd_mpu401_uart_free;
554	spin_lock_init(&mpu->input_lock);
555	spin_lock_init(&mpu->output_lock);
556	spin_lock_init(&mpu->timer_lock);
557	mpu->hardware = hardware;
558	mpu->irq = -1;
559	if (! (info_flags & MPU401_INFO_INTEGRATED)) {
560		int res_size = hardware == MPU401_HW_PC98II ? 4 : 2;
561		mpu->res = request_region(port, res_size, "MPU401 UART");
562		if (mpu->res == NULL) {
563			snd_printk(KERN_ERR "mpu401_uart: "
564				   "unable to grab port 0x%lx size %d\n",
565				   port, res_size);
566			snd_device_free(card, rmidi);
567			return -EBUSY;
568		}
569	}
570	if (info_flags & MPU401_INFO_MMIO) {
571		mpu->write = mpu401_write_mmio;
572		mpu->read = mpu401_read_mmio;
573	} else {
574		mpu->write = mpu401_write_port;
575		mpu->read = mpu401_read_port;
576	}
577	mpu->port = port;
578	if (hardware == MPU401_HW_PC98II)
579		mpu->cport = port + 2;
580	else
581		mpu->cport = port + 1;
582	if (irq >= 0) {
583		if (request_irq(irq, snd_mpu401_uart_interrupt, 0,
584				"MPU401 UART", (void *) mpu)) {
585			snd_printk(KERN_ERR "mpu401_uart: "
586				   "unable to grab IRQ %d\n", irq);
587			snd_device_free(card, rmidi);
588			return -EBUSY;
589		}
590	}
591	if (irq < 0 && !(info_flags & MPU401_INFO_IRQ_HOOK))
592		info_flags |= MPU401_INFO_USE_TIMER;
593	mpu->info_flags = info_flags;
594	mpu->irq = irq;
595	if (card->shortname[0])
596		snprintf(rmidi->name, sizeof(rmidi->name), "%s MIDI",
597			 card->shortname);
598	else
599		sprintf(rmidi->name, "MPU-401 MIDI %d-%d",card->number, device);
600	if (out_enable) {
601		snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
602				    &snd_mpu401_uart_output);
603		rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
604	}
605	if (in_enable) {
606		snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
607				    &snd_mpu401_uart_input);
608		rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
609		if (out_enable)
610			rmidi->info_flags |= SNDRV_RAWMIDI_INFO_DUPLEX;
611	}
612	mpu->rmidi = rmidi;
613	if (rrawmidi)
614		*rrawmidi = rmidi;
615	return 0;
616}
617
618EXPORT_SYMBOL(snd_mpu401_uart_new);
619
620/*
621 *  INIT part
622 */
623
624static int __init alsa_mpu401_uart_init(void)
625{
626	return 0;
627}
628
629static void __exit alsa_mpu401_uart_exit(void)
630{
631}
632
633module_init(alsa_mpu401_uart_init)
634module_exit(alsa_mpu401_uart_exit)
635