xref: /openbmc/linux/sound/mips/ad1843.c (revision d2ba09c1)
1 /*
2  *   AD1843 low level driver
3  *
4  *   Copyright 2003 Vivien Chappelier <vivien.chappelier@linux-mips.org>
5  *   Copyright 2008 Thomas Bogendoerfer <tsbogend@alpha.franken.de>
6  *
7  *   inspired from vwsnd.c (SGI VW audio driver)
8  *     Copyright 1999 Silicon Graphics, Inc.  All rights reserved.
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  */
25 
26 #include <linux/init.h>
27 #include <linux/sched.h>
28 #include <linux/errno.h>
29 #include <sound/core.h>
30 #include <sound/pcm.h>
31 #include <sound/ad1843.h>
32 
33 /*
34  * AD1843 bitfield definitions.  All are named as in the AD1843 data
35  * sheet, with ad1843_ prepended and individual bit numbers removed.
36  *
37  * E.g., bits LSS0 through LSS2 become ad1843_LSS.
38  *
39  * Only the bitfields we need are defined.
40  */
41 
42 struct ad1843_bitfield {
43 	char reg;
44 	char lo_bit;
45 	char nbits;
46 };
47 
48 static const struct ad1843_bitfield
49 	ad1843_PDNO   = {  0, 14,  1 },	/* Converter Power-Down Flag */
50 	ad1843_INIT   = {  0, 15,  1 },	/* Clock Initialization Flag */
51 	ad1843_RIG    = {  2,  0,  4 },	/* Right ADC Input Gain */
52 	ad1843_RMGE   = {  2,  4,  1 },	/* Right ADC Mic Gain Enable */
53 	ad1843_RSS    = {  2,  5,  3 },	/* Right ADC Source Select */
54 	ad1843_LIG    = {  2,  8,  4 },	/* Left ADC Input Gain */
55 	ad1843_LMGE   = {  2, 12,  1 },	/* Left ADC Mic Gain Enable */
56 	ad1843_LSS    = {  2, 13,  3 },	/* Left ADC Source Select */
57 	ad1843_RD2M   = {  3,  0,  5 },	/* Right DAC 2 Mix Gain/Atten */
58 	ad1843_RD2MM  = {  3,  7,  1 },	/* Right DAC 2 Mix Mute */
59 	ad1843_LD2M   = {  3,  8,  5 },	/* Left DAC 2 Mix Gain/Atten */
60 	ad1843_LD2MM  = {  3, 15,  1 },	/* Left DAC 2 Mix Mute */
61 	ad1843_RX1M   = {  4,  0,  5 },	/* Right Aux 1 Mix Gain/Atten */
62 	ad1843_RX1MM  = {  4,  7,  1 },	/* Right Aux 1 Mix Mute */
63 	ad1843_LX1M   = {  4,  8,  5 },	/* Left Aux 1 Mix Gain/Atten */
64 	ad1843_LX1MM  = {  4, 15,  1 },	/* Left Aux 1 Mix Mute */
65 	ad1843_RX2M   = {  5,  0,  5 },	/* Right Aux 2 Mix Gain/Atten */
66 	ad1843_RX2MM  = {  5,  7,  1 },	/* Right Aux 2 Mix Mute */
67 	ad1843_LX2M   = {  5,  8,  5 },	/* Left Aux 2 Mix Gain/Atten */
68 	ad1843_LX2MM  = {  5, 15,  1 },	/* Left Aux 2 Mix Mute */
69 	ad1843_RMCM   = {  7,  0,  5 },	/* Right Mic Mix Gain/Atten */
70 	ad1843_RMCMM  = {  7,  7,  1 },	/* Right Mic Mix Mute */
71 	ad1843_LMCM   = {  7,  8,  5 },	/* Left Mic Mix Gain/Atten */
72 	ad1843_LMCMM  = {  7, 15,  1 },	/* Left Mic Mix Mute */
73 	ad1843_HPOS   = {  8,  4,  1 },	/* Headphone Output Voltage Swing */
74 	ad1843_HPOM   = {  8,  5,  1 },	/* Headphone Output Mute */
75 	ad1843_MPOM   = {  8,  6,  1 },	/* Mono Output Mute */
76 	ad1843_RDA1G  = {  9,  0,  6 },	/* Right DAC1 Analog/Digital Gain */
77 	ad1843_RDA1GM = {  9,  7,  1 },	/* Right DAC1 Analog Mute */
78 	ad1843_LDA1G  = {  9,  8,  6 },	/* Left DAC1 Analog/Digital Gain */
79 	ad1843_LDA1GM = {  9, 15,  1 },	/* Left DAC1 Analog Mute */
80 	ad1843_RDA2G  = { 10,  0,  6 },	/* Right DAC2 Analog/Digital Gain */
81 	ad1843_RDA2GM = { 10,  7,  1 },	/* Right DAC2 Analog Mute */
82 	ad1843_LDA2G  = { 10,  8,  6 },	/* Left DAC2 Analog/Digital Gain */
83 	ad1843_LDA2GM = { 10, 15,  1 },	/* Left DAC2 Analog Mute */
84 	ad1843_RDA1AM = { 11,  7,  1 },	/* Right DAC1 Digital Mute */
85 	ad1843_LDA1AM = { 11, 15,  1 },	/* Left DAC1 Digital Mute */
86 	ad1843_RDA2AM = { 12,  7,  1 },	/* Right DAC2 Digital Mute */
87 	ad1843_LDA2AM = { 12, 15,  1 },	/* Left DAC2 Digital Mute */
88 	ad1843_ADLC   = { 15,  0,  2 },	/* ADC Left Sample Rate Source */
89 	ad1843_ADRC   = { 15,  2,  2 },	/* ADC Right Sample Rate Source */
90 	ad1843_DA1C   = { 15,  8,  2 },	/* DAC1 Sample Rate Source */
91 	ad1843_DA2C   = { 15, 10,  2 },	/* DAC2 Sample Rate Source */
92 	ad1843_C1C    = { 17,  0, 16 },	/* Clock 1 Sample Rate Select */
93 	ad1843_C2C    = { 20,  0, 16 },	/* Clock 2 Sample Rate Select */
94 	ad1843_C3C    = { 23,  0, 16 },	/* Clock 3 Sample Rate Select */
95 	ad1843_DAADL  = { 25,  4,  2 },	/* Digital ADC Left Source Select */
96 	ad1843_DAADR  = { 25,  6,  2 },	/* Digital ADC Right Source Select */
97 	ad1843_DAMIX  = { 25, 14,  1 },	/* DAC Digital Mix Enable */
98 	ad1843_DRSFLT = { 25, 15,  1 },	/* Digital Reampler Filter Mode */
99 	ad1843_ADLF   = { 26,  0,  2 }, /* ADC Left Channel Data Format */
100 	ad1843_ADRF   = { 26,  2,  2 }, /* ADC Right Channel Data Format */
101 	ad1843_ADTLK  = { 26,  4,  1 },	/* ADC Transmit Lock Mode Select */
102 	ad1843_SCF    = { 26,  7,  1 },	/* SCLK Frequency Select */
103 	ad1843_DA1F   = { 26,  8,  2 },	/* DAC1 Data Format Select */
104 	ad1843_DA2F   = { 26, 10,  2 },	/* DAC2 Data Format Select */
105 	ad1843_DA1SM  = { 26, 14,  1 },	/* DAC1 Stereo/Mono Mode Select */
106 	ad1843_DA2SM  = { 26, 15,  1 },	/* DAC2 Stereo/Mono Mode Select */
107 	ad1843_ADLEN  = { 27,  0,  1 },	/* ADC Left Channel Enable */
108 	ad1843_ADREN  = { 27,  1,  1 },	/* ADC Right Channel Enable */
109 	ad1843_AAMEN  = { 27,  4,  1 },	/* Analog to Analog Mix Enable */
110 	ad1843_ANAEN  = { 27,  7,  1 },	/* Analog Channel Enable */
111 	ad1843_DA1EN  = { 27,  8,  1 },	/* DAC1 Enable */
112 	ad1843_DA2EN  = { 27,  9,  1 },	/* DAC2 Enable */
113 	ad1843_DDMEN  = { 27, 12,  1 },	/* DAC2 to DAC1 Mix  Enable */
114 	ad1843_C1EN   = { 28, 11,  1 },	/* Clock Generator 1 Enable */
115 	ad1843_C2EN   = { 28, 12,  1 },	/* Clock Generator 2 Enable */
116 	ad1843_C3EN   = { 28, 13,  1 },	/* Clock Generator 3 Enable */
117 	ad1843_PDNI   = { 28, 15,  1 };	/* Converter Power Down */
118 
119 /*
120  * The various registers of the AD1843 use three different formats for
121  * specifying gain.  The ad1843_gain structure parameterizes the
122  * formats.
123  */
124 
125 struct ad1843_gain {
126 	int	negative;		/* nonzero if gain is negative. */
127 	const struct ad1843_bitfield *lfield;
128 	const struct ad1843_bitfield *rfield;
129 	const struct ad1843_bitfield *lmute;
130 	const struct ad1843_bitfield *rmute;
131 };
132 
133 static const struct ad1843_gain ad1843_gain_RECLEV = {
134 	.negative = 0,
135 	.lfield   = &ad1843_LIG,
136 	.rfield   = &ad1843_RIG
137 };
138 static const struct ad1843_gain ad1843_gain_LINE = {
139 	.negative = 1,
140 	.lfield   = &ad1843_LX1M,
141 	.rfield   = &ad1843_RX1M,
142 	.lmute    = &ad1843_LX1MM,
143 	.rmute    = &ad1843_RX1MM
144 };
145 static const struct ad1843_gain ad1843_gain_LINE_2 = {
146 	.negative = 1,
147 	.lfield   = &ad1843_LDA2G,
148 	.rfield   = &ad1843_RDA2G,
149 	.lmute    = &ad1843_LDA2GM,
150 	.rmute    = &ad1843_RDA2GM
151 };
152 static const struct ad1843_gain ad1843_gain_MIC = {
153 	.negative = 1,
154 	.lfield   = &ad1843_LMCM,
155 	.rfield   = &ad1843_RMCM,
156 	.lmute    = &ad1843_LMCMM,
157 	.rmute    = &ad1843_RMCMM
158 };
159 static const struct ad1843_gain ad1843_gain_PCM_0 = {
160 	.negative = 1,
161 	.lfield   = &ad1843_LDA1G,
162 	.rfield   = &ad1843_RDA1G,
163 	.lmute    = &ad1843_LDA1GM,
164 	.rmute    = &ad1843_RDA1GM
165 };
166 static const struct ad1843_gain ad1843_gain_PCM_1 = {
167 	.negative = 1,
168 	.lfield   = &ad1843_LD2M,
169 	.rfield   = &ad1843_RD2M,
170 	.lmute    = &ad1843_LD2MM,
171 	.rmute    = &ad1843_RD2MM
172 };
173 
174 static const struct ad1843_gain *ad1843_gain[AD1843_GAIN_SIZE] =
175 {
176 	&ad1843_gain_RECLEV,
177 	&ad1843_gain_LINE,
178 	&ad1843_gain_LINE_2,
179 	&ad1843_gain_MIC,
180 	&ad1843_gain_PCM_0,
181 	&ad1843_gain_PCM_1,
182 };
183 
184 /* read the current value of an AD1843 bitfield. */
185 
186 static int ad1843_read_bits(struct snd_ad1843 *ad1843,
187 			    const struct ad1843_bitfield *field)
188 {
189 	int w;
190 
191 	w = ad1843->read(ad1843->chip, field->reg);
192 	return w >> field->lo_bit & ((1 << field->nbits) - 1);
193 }
194 
195 /*
196  * write a new value to an AD1843 bitfield and return the old value.
197  */
198 
199 static int ad1843_write_bits(struct snd_ad1843 *ad1843,
200 			     const struct ad1843_bitfield *field,
201 			     int newval)
202 {
203 	int w, mask, oldval, newbits;
204 
205 	w = ad1843->read(ad1843->chip, field->reg);
206 	mask = ((1 << field->nbits) - 1) << field->lo_bit;
207 	oldval = (w & mask) >> field->lo_bit;
208 	newbits = (newval << field->lo_bit) & mask;
209 	w = (w & ~mask) | newbits;
210 	ad1843->write(ad1843->chip, field->reg, w);
211 
212 	return oldval;
213 }
214 
215 /*
216  * ad1843_read_multi reads multiple bitfields from the same AD1843
217  * register.  It uses a single read cycle to do it.  (Reading the
218  * ad1843 requires 256 bit times at 12.288 MHz, or nearly 20
219  * microseconds.)
220  *
221  * Called like this.
222  *
223  *  ad1843_read_multi(ad1843, nfields,
224  *		      &ad1843_FIELD1, &val1,
225  *		      &ad1843_FIELD2, &val2, ...);
226  */
227 
228 static void ad1843_read_multi(struct snd_ad1843 *ad1843, int argcount, ...)
229 {
230 	va_list ap;
231 	const struct ad1843_bitfield *fp;
232 	int w = 0, mask, *value, reg = -1;
233 
234 	va_start(ap, argcount);
235 	while (--argcount >= 0) {
236 		fp = va_arg(ap, const struct ad1843_bitfield *);
237 		value = va_arg(ap, int *);
238 		if (reg == -1) {
239 			reg = fp->reg;
240 			w = ad1843->read(ad1843->chip, reg);
241 		}
242 
243 		mask = (1 << fp->nbits) - 1;
244 		*value = w >> fp->lo_bit & mask;
245 	}
246 	va_end(ap);
247 }
248 
249 /*
250  * ad1843_write_multi stores multiple bitfields into the same AD1843
251  * register.  It uses one read and one write cycle to do it.
252  *
253  * Called like this.
254  *
255  *  ad1843_write_multi(ad1843, nfields,
256  *		       &ad1843_FIELD1, val1,
257  *		       &ad1843_FIELF2, val2, ...);
258  */
259 
260 static void ad1843_write_multi(struct snd_ad1843 *ad1843, int argcount, ...)
261 {
262 	va_list ap;
263 	int reg;
264 	const struct ad1843_bitfield *fp;
265 	int value;
266 	int w, m, mask, bits;
267 
268 	mask = 0;
269 	bits = 0;
270 	reg = -1;
271 
272 	va_start(ap, argcount);
273 	while (--argcount >= 0) {
274 		fp = va_arg(ap, const struct ad1843_bitfield *);
275 		value = va_arg(ap, int);
276 		if (reg == -1)
277 			reg = fp->reg;
278 		else
279 			WARN_ON(reg != fp->reg);
280 		m = ((1 << fp->nbits) - 1) << fp->lo_bit;
281 		mask |= m;
282 		bits |= (value << fp->lo_bit) & m;
283 	}
284 	va_end(ap);
285 
286 	if (~mask & 0xFFFF)
287 		w = ad1843->read(ad1843->chip, reg);
288 	else
289 		w = 0;
290 	w = (w & ~mask) | bits;
291 	ad1843->write(ad1843->chip, reg, w);
292 }
293 
294 int ad1843_get_gain_max(struct snd_ad1843 *ad1843, int id)
295 {
296 	const struct ad1843_gain *gp = ad1843_gain[id];
297 	int ret;
298 
299 	ret = (1 << gp->lfield->nbits);
300 	if (!gp->lmute)
301 		ret -= 1;
302 	return ret;
303 }
304 
305 /*
306  * ad1843_get_gain reads the specified register and extracts the gain value
307  * using the supplied gain type.
308  */
309 
310 int ad1843_get_gain(struct snd_ad1843 *ad1843, int id)
311 {
312 	int lg, rg, lm, rm;
313 	const struct ad1843_gain *gp = ad1843_gain[id];
314 	unsigned short mask = (1 << gp->lfield->nbits) - 1;
315 
316 	ad1843_read_multi(ad1843, 2, gp->lfield, &lg, gp->rfield, &rg);
317 	if (gp->negative) {
318 		lg = mask - lg;
319 		rg = mask - rg;
320 	}
321 	if (gp->lmute) {
322 		ad1843_read_multi(ad1843, 2, gp->lmute, &lm, gp->rmute, &rm);
323 		if (lm)
324 			lg = 0;
325 		if (rm)
326 			rg = 0;
327 	}
328 	return lg << 0 | rg << 8;
329 }
330 
331 /*
332  * Set an audio channel's gain.
333  *
334  * Returns the new gain, which may be lower than the old gain.
335  */
336 
337 int ad1843_set_gain(struct snd_ad1843 *ad1843, int id, int newval)
338 {
339 	const struct ad1843_gain *gp = ad1843_gain[id];
340 	unsigned short mask = (1 << gp->lfield->nbits) - 1;
341 
342 	int lg = (newval >> 0) & mask;
343 	int rg = (newval >> 8) & mask;
344 	int lm = (lg == 0) ? 1 : 0;
345 	int rm = (rg == 0) ? 1 : 0;
346 
347 	if (gp->negative) {
348 		lg = mask - lg;
349 		rg = mask - rg;
350 	}
351 	if (gp->lmute)
352 		ad1843_write_multi(ad1843, 2, gp->lmute, lm, gp->rmute, rm);
353 	ad1843_write_multi(ad1843, 2, gp->lfield, lg, gp->rfield, rg);
354 	return ad1843_get_gain(ad1843, id);
355 }
356 
357 /* Returns the current recording source */
358 
359 int ad1843_get_recsrc(struct snd_ad1843 *ad1843)
360 {
361 	int val = ad1843_read_bits(ad1843, &ad1843_LSS);
362 
363 	if (val < 0 || val > 2) {
364 		val = 2;
365 		ad1843_write_multi(ad1843, 2,
366 				   &ad1843_LSS, val, &ad1843_RSS, val);
367 	}
368 	return val;
369 }
370 
371 /*
372  * Set recording source.
373  *
374  * Returns newsrc on success, -errno on failure.
375  */
376 
377 int ad1843_set_recsrc(struct snd_ad1843 *ad1843, int newsrc)
378 {
379 	if (newsrc < 0 || newsrc > 2)
380 		return -EINVAL;
381 
382 	ad1843_write_multi(ad1843, 2, &ad1843_LSS, newsrc, &ad1843_RSS, newsrc);
383 	return newsrc;
384 }
385 
386 /* Setup ad1843 for D/A conversion. */
387 
388 void ad1843_setup_dac(struct snd_ad1843 *ad1843,
389 		      unsigned int id,
390 		      unsigned int framerate,
391 		      snd_pcm_format_t fmt,
392 		      unsigned int channels)
393 {
394 	int ad_fmt = 0, ad_mode = 0;
395 
396 	switch (fmt) {
397 	case SNDRV_PCM_FORMAT_S8:
398 		ad_fmt = 0;
399 		break;
400 	case SNDRV_PCM_FORMAT_U8:
401 		ad_fmt = 0;
402 		break;
403 	case SNDRV_PCM_FORMAT_S16_LE:
404 		ad_fmt = 1;
405 		break;
406 	case SNDRV_PCM_FORMAT_MU_LAW:
407 		ad_fmt = 2;
408 		break;
409 	case SNDRV_PCM_FORMAT_A_LAW:
410 		ad_fmt = 3;
411 		break;
412 	default:
413 		break;
414 	}
415 
416 	switch (channels) {
417 	case 2:
418 		ad_mode = 0;
419 		break;
420 	case 1:
421 		ad_mode = 1;
422 		break;
423 	default:
424 		break;
425 	}
426 
427 	if (id) {
428 		ad1843_write_bits(ad1843, &ad1843_C2C, framerate);
429 		ad1843_write_multi(ad1843, 2,
430 				   &ad1843_DA2SM, ad_mode,
431 				   &ad1843_DA2F, ad_fmt);
432 	} else {
433 		ad1843_write_bits(ad1843, &ad1843_C1C, framerate);
434 		ad1843_write_multi(ad1843, 2,
435 				   &ad1843_DA1SM, ad_mode,
436 				   &ad1843_DA1F, ad_fmt);
437 	}
438 }
439 
440 void ad1843_shutdown_dac(struct snd_ad1843 *ad1843, unsigned int id)
441 {
442 	if (id)
443 		ad1843_write_bits(ad1843, &ad1843_DA2F, 1);
444 	else
445 		ad1843_write_bits(ad1843, &ad1843_DA1F, 1);
446 }
447 
448 void ad1843_setup_adc(struct snd_ad1843 *ad1843,
449 		      unsigned int framerate,
450 		      snd_pcm_format_t fmt,
451 		      unsigned int channels)
452 {
453 	int da_fmt = 0;
454 
455 	switch (fmt) {
456 	case SNDRV_PCM_FORMAT_S8:	da_fmt = 0; break;
457 	case SNDRV_PCM_FORMAT_U8:	da_fmt = 0; break;
458 	case SNDRV_PCM_FORMAT_S16_LE:	da_fmt = 1; break;
459 	case SNDRV_PCM_FORMAT_MU_LAW:	da_fmt = 2; break;
460 	case SNDRV_PCM_FORMAT_A_LAW:	da_fmt = 3; break;
461 	default:		break;
462 	}
463 
464 	ad1843_write_bits(ad1843, &ad1843_C3C, framerate);
465 	ad1843_write_multi(ad1843, 2,
466 			   &ad1843_ADLF, da_fmt, &ad1843_ADRF, da_fmt);
467 }
468 
469 void ad1843_shutdown_adc(struct snd_ad1843 *ad1843)
470 {
471 	/* nothing to do */
472 }
473 
474 /*
475  * Fully initialize the ad1843.  As described in the AD1843 data
476  * sheet, section "START-UP SEQUENCE".  The numbered comments are
477  * subsection headings from the data sheet.  See the data sheet, pages
478  * 52-54, for more info.
479  *
480  * return 0 on success, -errno on failure.  */
481 
482 int ad1843_init(struct snd_ad1843 *ad1843)
483 {
484 	unsigned long later;
485 
486 	if (ad1843_read_bits(ad1843, &ad1843_INIT) != 0) {
487 		printk(KERN_ERR "ad1843: AD1843 won't initialize\n");
488 		return -EIO;
489 	}
490 
491 	ad1843_write_bits(ad1843, &ad1843_SCF, 1);
492 
493 	/* 4. Put the conversion resources into standby. */
494 	ad1843_write_bits(ad1843, &ad1843_PDNI, 0);
495 	later = jiffies + msecs_to_jiffies(500);
496 
497 	while (ad1843_read_bits(ad1843, &ad1843_PDNO)) {
498 		if (time_after(jiffies, later)) {
499 			printk(KERN_ERR
500 			       "ad1843: AD1843 won't power up\n");
501 			return -EIO;
502 		}
503 		schedule_timeout_interruptible(5);
504 	}
505 
506 	/* 5. Power up the clock generators and enable clock output pins. */
507 	ad1843_write_multi(ad1843, 3,
508 			   &ad1843_C1EN, 1,
509 			   &ad1843_C2EN, 1,
510 			   &ad1843_C3EN, 1);
511 
512 	/* 6. Configure conversion resources while they are in standby. */
513 
514 	/* DAC1/2 use clock 1/2 as source, ADC uses clock 3.  Always. */
515 	ad1843_write_multi(ad1843, 4,
516 			   &ad1843_DA1C, 1,
517 			   &ad1843_DA2C, 2,
518 			   &ad1843_ADLC, 3,
519 			   &ad1843_ADRC, 3);
520 
521 	/* 7. Enable conversion resources. */
522 	ad1843_write_bits(ad1843, &ad1843_ADTLK, 1);
523 	ad1843_write_multi(ad1843, 7,
524 			   &ad1843_ANAEN, 1,
525 			   &ad1843_AAMEN, 1,
526 			   &ad1843_DA1EN, 1,
527 			   &ad1843_DA2EN, 1,
528 			   &ad1843_DDMEN, 1,
529 			   &ad1843_ADLEN, 1,
530 			   &ad1843_ADREN, 1);
531 
532 	/* 8. Configure conversion resources while they are enabled. */
533 
534 	/* set gain to 0 for all channels */
535 	ad1843_set_gain(ad1843, AD1843_GAIN_RECLEV, 0);
536 	ad1843_set_gain(ad1843, AD1843_GAIN_LINE, 0);
537 	ad1843_set_gain(ad1843, AD1843_GAIN_LINE_2, 0);
538 	ad1843_set_gain(ad1843, AD1843_GAIN_MIC, 0);
539 	ad1843_set_gain(ad1843, AD1843_GAIN_PCM_0, 0);
540 	ad1843_set_gain(ad1843, AD1843_GAIN_PCM_1, 0);
541 
542 	/* Unmute all channels. */
543 	/* DAC1 */
544 	ad1843_write_multi(ad1843, 2, &ad1843_LDA1GM, 0, &ad1843_RDA1GM, 0);
545 	/* DAC2 */
546 	ad1843_write_multi(ad1843, 2, &ad1843_LDA2GM, 0, &ad1843_RDA2GM, 0);
547 
548 	/* Set default recording source to Line In and set
549 	 * mic gain to +20 dB.
550 	 */
551 	ad1843_set_recsrc(ad1843, 2);
552 	ad1843_write_multi(ad1843, 2, &ad1843_LMGE, 1, &ad1843_RMGE, 1);
553 
554 	/* Set Speaker Out level to +/- 4V and unmute it. */
555 	ad1843_write_multi(ad1843, 3,
556 			   &ad1843_HPOS, 1,
557 			   &ad1843_HPOM, 0,
558 			   &ad1843_MPOM, 0);
559 
560 	return 0;
561 }
562