sound/mips/ad1843.c

   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                         BUG_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 }