Free Electrons

Embedded Linux Experts

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
/*
 * pas2_pcm.c Audio routines for PAS16
 *
 *
 * Copyright (C) by Hannu Savolainen 1993-1997
 *
 * OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
 * Version 2 (June 1991). See the "COPYING" file distributed with this software
 * for more info.
 *
 *
 * Thomas Sailer   : ioctl code reworked (vmalloc/vfree removed)
 * Alan Cox	   : Swatted a double allocation of device bug. Made a few
 *		     more things module options.
 * Bartlomiej Zolnierkiewicz : Added __init to pas_pcm_init()
 */

#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/timex.h>
#include "sound_config.h"

#include "pas2.h"

#ifndef DEB
#define DEB(WHAT)
#endif

#define PAS_PCM_INTRBITS (0x08)
/*
 * Sample buffer timer interrupt enable
 */

#define PCM_NON	0
#define PCM_DAC	1
#define PCM_ADC	2

static unsigned long pcm_speed; 	/* sampling rate */
static unsigned char pcm_channels = 1;	/* channels (1 or 2) */
static unsigned char pcm_bits = 8;	/* bits/sample (8 or 16) */
static unsigned char pcm_filter;	/* filter FLAG */
static unsigned char pcm_mode = PCM_NON;
static unsigned long pcm_count;
static unsigned short pcm_bitsok = 8;	/* mask of OK bits */
static int      pcm_busy;
int             pas_audiodev = -1;
static int      open_mode;

extern spinlock_t pas_lock;

static int pcm_set_speed(int arg)
{
	int foo, tmp;
	unsigned long flags;

	if (arg == 0)
		return pcm_speed;

	if (arg > 44100)
		arg = 44100;
	if (arg < 5000)
		arg = 5000;

	if (pcm_channels & 2)
	{
		foo = ((PIT_TICK_RATE / 2) + (arg / 2)) / arg;
		arg = ((PIT_TICK_RATE / 2) + (foo / 2)) / foo;
	}
	else
	{
		foo = (PIT_TICK_RATE + (arg / 2)) / arg;
		arg = (PIT_TICK_RATE + (foo / 2)) / foo;
	}

	pcm_speed = arg;

	tmp = pas_read(0x0B8A);

	/*
	 * Set anti-aliasing filters according to sample rate. You really *NEED*
	 * to enable this feature for all normal recording unless you want to
	 * experiment with aliasing effects.
	 * These filters apply to the selected "recording" source.
	 * I (pfw) don't know the encoding of these 5 bits. The values shown
	 * come from the SDK found on ftp.uwp.edu:/pub/msdos/proaudio/.
	 *
	 * I cleared bit 5 of these values, since that bit controls the master
	 * mute flag. (Olav W├Âlfelschneider)
	 *
	 */
#if !defined NO_AUTO_FILTER_SET
	tmp &= 0xe0;
	if (pcm_speed >= 2 * 17897)
		tmp |= 0x01;
	else if (pcm_speed >= 2 * 15909)
		tmp |= 0x02;
	else if (pcm_speed >= 2 * 11931)
		tmp |= 0x09;
	else if (pcm_speed >= 2 * 8948)
		tmp |= 0x11;
	else if (pcm_speed >= 2 * 5965)
		tmp |= 0x19;
	else if (pcm_speed >= 2 * 2982)
		tmp |= 0x04;
	pcm_filter = tmp;
#endif

	spin_lock_irqsave(&pas_lock, flags);

	pas_write(tmp & ~(0x40 | 0x80), 0x0B8A);
	pas_write(0x00 | 0x30 | 0x04, 0x138B);
	pas_write(foo & 0xff, 0x1388);
	pas_write((foo >> 8) & 0xff, 0x1388);
	pas_write(tmp, 0x0B8A);

	spin_unlock_irqrestore(&pas_lock, flags);

	return pcm_speed;
}

static int pcm_set_channels(int arg)
{

	if ((arg != 1) && (arg != 2))
		return pcm_channels;

	if (arg != pcm_channels)
	{
		pas_write(pas_read(0xF8A) ^ 0x20, 0xF8A);

		pcm_channels = arg;
		pcm_set_speed(pcm_speed);	/* The speed must be reinitialized */
	}
	return pcm_channels;
}

static int pcm_set_bits(int arg)
{
	if (arg == 0)
		return pcm_bits;

	if ((arg & pcm_bitsok) != arg)
		return pcm_bits;

	if (arg != pcm_bits)
	{
		pas_write(pas_read(0x8389) ^ 0x04, 0x8389);

		pcm_bits = arg;
	}
	return pcm_bits;
}

static int pas_audio_ioctl(int dev, unsigned int cmd, void __user *arg)
{
	int val, ret;
	int __user *p = arg;

	DEB(printk("pas2_pcm.c: static int pas_audio_ioctl(unsigned int cmd = %X, unsigned int arg = %X)\n", cmd, arg));

	switch (cmd) 
	{
	case SOUND_PCM_WRITE_RATE:
		if (get_user(val, p)) 
			return -EFAULT;
		ret = pcm_set_speed(val);
		break;

	case SOUND_PCM_READ_RATE:
		ret = pcm_speed;
		break;
		
	case SNDCTL_DSP_STEREO:
		if (get_user(val, p)) 
			return -EFAULT;
		ret = pcm_set_channels(val + 1) - 1;
		break;

	case SOUND_PCM_WRITE_CHANNELS:
		if (get_user(val, p)) 
			return -EFAULT;
		ret = pcm_set_channels(val);
		break;

	case SOUND_PCM_READ_CHANNELS:
		ret = pcm_channels;
		break;

	case SNDCTL_DSP_SETFMT:
		if (get_user(val, p))
			return -EFAULT;
		ret = pcm_set_bits(val);
		break;
		
	case SOUND_PCM_READ_BITS:
		ret = pcm_bits;
		break;
  
	default:
		return -EINVAL;
	}
	return put_user(ret, p);
}

static void pas_audio_reset(int dev)
{
	DEB(printk("pas2_pcm.c: static void pas_audio_reset(void)\n"));

	pas_write(pas_read(0xF8A) & ~0x40, 0xF8A);	/* Disable PCM */
}

static int pas_audio_open(int dev, int mode)
{
	int             err;
	unsigned long   flags;

	DEB(printk("pas2_pcm.c: static int pas_audio_open(int mode = %X)\n", mode));

	spin_lock_irqsave(&pas_lock, flags);
	if (pcm_busy)
	{
		spin_unlock_irqrestore(&pas_lock, flags);
		return -EBUSY;
	}
	pcm_busy = 1;
	spin_unlock_irqrestore(&pas_lock, flags);

	if ((err = pas_set_intr(PAS_PCM_INTRBITS)) < 0)
		return err;


	pcm_count = 0;
	open_mode = mode;

	return 0;
}

static void pas_audio_close(int dev)
{
	unsigned long   flags;

	DEB(printk("pas2_pcm.c: static void pas_audio_close(void)\n"));

	spin_lock_irqsave(&pas_lock, flags);

	pas_audio_reset(dev);
	pas_remove_intr(PAS_PCM_INTRBITS);
	pcm_mode = PCM_NON;

	pcm_busy = 0;
	spin_unlock_irqrestore(&pas_lock, flags);
}

static void pas_audio_output_block(int dev, unsigned long buf, int count,
		       int intrflag)
{
	unsigned long   flags, cnt;

	DEB(printk("pas2_pcm.c: static void pas_audio_output_block(char *buf = %P, int count = %X)\n", buf, count));

	cnt = count;
	if (audio_devs[dev]->dmap_out->dma > 3)
		cnt >>= 1;

	if (audio_devs[dev]->flags & DMA_AUTOMODE &&
	    intrflag &&
	    cnt == pcm_count)
		return;

	spin_lock_irqsave(&pas_lock, flags);

	pas_write(pas_read(0xF8A) & ~0x40,
		  0xF8A);

	/* DMAbuf_start_dma (dev, buf, count, DMA_MODE_WRITE); */

	if (audio_devs[dev]->dmap_out->dma > 3)
		count >>= 1;

	if (count != pcm_count)
	{
		pas_write(pas_read(0x0B8A) & ~0x80, 0x0B8A);
		pas_write(0x40 | 0x30 | 0x04, 0x138B);
		pas_write(count & 0xff, 0x1389);
		pas_write((count >> 8) & 0xff, 0x1389);
		pas_write(pas_read(0x0B8A) | 0x80, 0x0B8A);

		pcm_count = count;
	}
	pas_write(pas_read(0x0B8A) | 0x80 | 0x40, 0x0B8A);
#ifdef NO_TRIGGER
	pas_write(pas_read(0xF8A) | 0x40 | 0x10, 0xF8A);
#endif

	pcm_mode = PCM_DAC;

	spin_unlock_irqrestore(&pas_lock, flags);
}

static void pas_audio_start_input(int dev, unsigned long buf, int count,
		      int intrflag)
{
	unsigned long   flags;
	int             cnt;

	DEB(printk("pas2_pcm.c: static void pas_audio_start_input(char *buf = %P, int count = %X)\n", buf, count));

	cnt = count;
	if (audio_devs[dev]->dmap_out->dma > 3)
		cnt >>= 1;

	if (audio_devs[pas_audiodev]->flags & DMA_AUTOMODE &&
	    intrflag &&
	    cnt == pcm_count)
		return;

	spin_lock_irqsave(&pas_lock, flags);

	/* DMAbuf_start_dma (dev, buf, count, DMA_MODE_READ); */

	if (audio_devs[dev]->dmap_out->dma > 3)
		count >>= 1;

	if (count != pcm_count)
	{
		pas_write(pas_read(0x0B8A) & ~0x80, 0x0B8A);
		pas_write(0x40 | 0x30 | 0x04, 0x138B);
		pas_write(count & 0xff, 0x1389);
		pas_write((count >> 8) & 0xff, 0x1389);
		pas_write(pas_read(0x0B8A) | 0x80, 0x0B8A);

		pcm_count = count;
	}
	pas_write(pas_read(0x0B8A) | 0x80 | 0x40, 0x0B8A);
#ifdef NO_TRIGGER
	pas_write((pas_read(0xF8A) | 0x40) & ~0x10, 0xF8A);
#endif

	pcm_mode = PCM_ADC;

	spin_unlock_irqrestore(&pas_lock, flags);
}

#ifndef NO_TRIGGER
static void pas_audio_trigger(int dev, int state)
{
	unsigned long   flags;

	spin_lock_irqsave(&pas_lock, flags);
	state &= open_mode;

	if (state & PCM_ENABLE_OUTPUT)
		pas_write(pas_read(0xF8A) | 0x40 | 0x10, 0xF8A);
	else if (state & PCM_ENABLE_INPUT)
		pas_write((pas_read(0xF8A) | 0x40) & ~0x10, 0xF8A);
	else
		pas_write(pas_read(0xF8A) & ~0x40, 0xF8A);

	spin_unlock_irqrestore(&pas_lock, flags);
}
#endif

static int pas_audio_prepare_for_input(int dev, int bsize, int bcount)
{
	pas_audio_reset(dev);
	return 0;
}

static int pas_audio_prepare_for_output(int dev, int bsize, int bcount)
{
	pas_audio_reset(dev);
	return 0;
}

static struct audio_driver pas_audio_driver =
{
	.owner			= THIS_MODULE,
	.open			= pas_audio_open,
	.close			= pas_audio_close,
	.output_block		= pas_audio_output_block,
	.start_input		= pas_audio_start_input,
	.ioctl			= pas_audio_ioctl,
	.prepare_for_input	= pas_audio_prepare_for_input,
	.prepare_for_output	= pas_audio_prepare_for_output,
	.halt_io		= pas_audio_reset,
	.trigger		= pas_audio_trigger
};

void __init pas_pcm_init(struct address_info *hw_config)
{
	DEB(printk("pas2_pcm.c: long pas_pcm_init()\n"));

	pcm_bitsok = 8;
	if (pas_read(0xEF8B) & 0x08)
		pcm_bitsok |= 16;

	pcm_set_speed(DSP_DEFAULT_SPEED);

	if ((pas_audiodev = sound_install_audiodrv(AUDIO_DRIVER_VERSION,
					"Pro Audio Spectrum",
					&pas_audio_driver,
					sizeof(struct audio_driver),
					DMA_AUTOMODE,
					AFMT_U8 | AFMT_S16_LE,
					NULL,
					hw_config->dma,
					hw_config->dma)) < 0)
		printk(KERN_WARNING "PAS16: Too many PCM devices available\n");
}

void pas_pcm_interrupt(unsigned char status, int cause)
{
	if (cause == 1)
	{
		/*
		 * Halt the PCM first. Otherwise we don't have time to start a new
		 * block before the PCM chip proceeds to the next sample
		 */

		if (!(audio_devs[pas_audiodev]->flags & DMA_AUTOMODE))
			pas_write(pas_read(0xF8A) & ~0x40, 0xF8A);

		switch (pcm_mode)
		{
			case PCM_DAC:
				DMAbuf_outputintr(pas_audiodev, 1);
				break;

			case PCM_ADC:
				DMAbuf_inputintr(pas_audiodev);
				break;

			default:
				printk(KERN_WARNING "PAS: Unexpected PCM interrupt\n");
		}
	}
}