sound/soc/codecs/ad1938.c

   1 /*
   2  * File:         sound/soc/codecs/ad1938.c
   3  * Author:       Barry Song <Barry.Song@analog.com>
   4  *
   5  * Created:      June 04 2009
   6  * Description:  Driver for AD1938 sound chip
   7  *
   8  * Modified:
   9  *               Copyright 2009 Analog Devices Inc.
  10  *
  11  * Bugs:         Enter bugs at http://blackfin.uclinux.org/
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, see the file COPYING, or write
  25  * to the Free Software Foundation, Inc.,
  26  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  27  */
  28
  29 #include <linux/init.h>
  30 #include <linux/module.h>
  31 #include <linux/kernel.h>
  32 #include <linux/device.h>
  33 #include <sound/core.h>
  34 #include <sound/pcm.h>
  35 #include <sound/pcm_params.h>
  36 #include <sound/initval.h>
  37 #include <sound/soc.h>
  38 #include <sound/tlv.h>
  39 #include <sound/soc-dapm.h>
  40 #include <linux/spi/spi.h>
  41 #include "ad1938.h"
  42
  43 /* codec private data */
  44 struct ad1938_priv {
  45         struct snd_soc_codec codec;
  46         u8 reg_cache[AD1938_NUM_REGS];
  47 };
  48
  49 /* ad1938 register cache & default register settings */
  50 static const u8 ad1938_reg[AD1938_NUM_REGS] = {
  51         0, 0, 0, 0, 0, 0, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0, 0, 0,
  52 };
  53
  54 static struct snd_soc_codec *ad1938_codec;
  55 struct snd_soc_codec_device soc_codec_dev_ad1938;
  56 static int ad1938_register(struct ad1938_priv *ad1938);
  57 static void ad1938_unregister(struct ad1938_priv *ad1938);
  58
  59 /*
  60  * AD1938 volume/mute/de-emphasis etc. controls
  61  */
  62 static const char *ad1938_deemp[] = {"None", "48kHz", "44.1kHz", "32kHz"};
  63
  64 static const struct soc_enum ad1938_deemp_enum =
  65         SOC_ENUM_SINGLE(AD1938_DAC_CTRL2, 1, 4, ad1938_deemp);
  66
  67 static const struct snd_kcontrol_new ad1938_snd_controls[] = {
  68         /* DAC volume control */
  69         SOC_DOUBLE_R("DAC1  Volume", AD1938_DAC_L1_VOL,
  70                         AD1938_DAC_R1_VOL, 0, 0xFF, 1),
  71         SOC_DOUBLE_R("DAC2  Volume", AD1938_DAC_L2_VOL,
  72                         AD1938_DAC_R2_VOL, 0, 0xFF, 1),
  73         SOC_DOUBLE_R("DAC3  Volume", AD1938_DAC_L3_VOL,
  74                         AD1938_DAC_R3_VOL, 0, 0xFF, 1),
  75         SOC_DOUBLE_R("DAC4  Volume", AD1938_DAC_L4_VOL,
  76                         AD1938_DAC_R4_VOL, 0, 0xFF, 1),
  77
  78         /* ADC switch control */
  79         SOC_DOUBLE("ADC1 Switch", AD1938_ADC_CTRL0, AD1938_ADCL1_MUTE,
  80                 AD1938_ADCR1_MUTE, 1, 1),
  81         SOC_DOUBLE("ADC2 Switch", AD1938_ADC_CTRL0, AD1938_ADCL2_MUTE,
  82                 AD1938_ADCR2_MUTE, 1, 1),
  83
  84         /* DAC switch control */
  85         SOC_DOUBLE("DAC1 Switch", AD1938_DAC_CHNL_MUTE, AD1938_DACL1_MUTE,
  86                 AD1938_DACR1_MUTE, 1, 1),
  87         SOC_DOUBLE("DAC2 Switch", AD1938_DAC_CHNL_MUTE, AD1938_DACL2_MUTE,
  88                 AD1938_DACR2_MUTE, 1, 1),
  89         SOC_DOUBLE("DAC3 Switch", AD1938_DAC_CHNL_MUTE, AD1938_DACL3_MUTE,
  90                 AD1938_DACR3_MUTE, 1, 1),
  91         SOC_DOUBLE("DAC4 Switch", AD1938_DAC_CHNL_MUTE, AD1938_DACL4_MUTE,
  92                 AD1938_DACR4_MUTE, 1, 1),
  93
  94         /* ADC high-pass filter */
  95         SOC_SINGLE("ADC High Pass Filter Switch", AD1938_ADC_CTRL0,
  96                         AD1938_ADC_HIGHPASS_FILTER, 1, 0),
  97
  98         /* DAC de-emphasis */
  99         SOC_ENUM("Playback Deemphasis", ad1938_deemp_enum),
 100 };
 101
 102 static const struct snd_soc_dapm_widget ad1938_dapm_widgets[] = {
 103         SND_SOC_DAPM_DAC("DAC", "Playback", AD1938_DAC_CTRL0, 0, 1),
 104         SND_SOC_DAPM_ADC("ADC", "Capture", SND_SOC_NOPM, 0, 0),
 105         SND_SOC_DAPM_SUPPLY("PLL_PWR", AD1938_PLL_CLK_CTRL0, 0, 1, NULL, 0),
 106         SND_SOC_DAPM_SUPPLY("ADC_PWR", AD1938_ADC_CTRL0, 0, 1, NULL, 0),
 107         SND_SOC_DAPM_OUTPUT("DAC1OUT"),
 108         SND_SOC_DAPM_OUTPUT("DAC2OUT"),
 109         SND_SOC_DAPM_OUTPUT("DAC3OUT"),
 110         SND_SOC_DAPM_OUTPUT("DAC4OUT"),
 111         SND_SOC_DAPM_INPUT("ADC1IN"),
 112         SND_SOC_DAPM_INPUT("ADC2IN"),
 113 };
 114
 115 static const struct snd_soc_dapm_route audio_paths[] = {
 116         { "DAC", NULL, "PLL_PWR" },
 117         { "ADC", NULL, "PLL_PWR" },
 118         { "DAC", NULL, "ADC_PWR" },
 119         { "ADC", NULL, "ADC_PWR" },
 120         { "DAC1OUT", "DAC1 Switch", "DAC" },
 121         { "DAC2OUT", "DAC2 Switch", "DAC" },
 122         { "DAC3OUT", "DAC3 Switch", "DAC" },
 123         { "DAC4OUT", "DAC4 Switch", "DAC" },
 124         { "ADC", "ADC1 Switch", "ADC1IN" },
 125         { "ADC", "ADC2 Switch", "ADC2IN" },
 126 };
 127
 128 /*
 129  * DAI ops entries
 130  */
 131
 132 static int ad1938_mute(struct snd_soc_dai *dai, int mute)
 133 {
 134         struct snd_soc_codec *codec = dai->codec;
 135         int reg;
 136
 137         reg = snd_soc_read(codec, AD1938_DAC_CTRL2);
 138         reg = (mute > 0) ? reg | AD1938_DAC_MASTER_MUTE : reg &
 139                 (~AD1938_DAC_MASTER_MUTE);
 140         snd_soc_write(codec, AD1938_DAC_CTRL2, reg);
 141
 142         return 0;
 143 }
 144
 145 static int ad1938_set_tdm_slot(struct snd_soc_dai *dai, unsigned int tx_mask,
 146                                unsigned int rx_mask, int slots, int width)
 147 {
 148         struct snd_soc_codec *codec = dai->codec;
 149         int dac_reg = snd_soc_read(codec, AD1938_DAC_CTRL1);
 150         int adc_reg = snd_soc_read(codec, AD1938_ADC_CTRL2);
 151
 152         dac_reg &= ~AD1938_DAC_CHAN_MASK;
 153         adc_reg &= ~AD1938_ADC_CHAN_MASK;
 154
 155         switch (slots) {
 156         case 2:
 157                 dac_reg |= AD1938_DAC_2_CHANNELS << AD1938_DAC_CHAN_SHFT;
 158                 adc_reg |= AD1938_ADC_2_CHANNELS << AD1938_ADC_CHAN_SHFT;
 159                 break;
 160         case 4:
 161                 dac_reg |= AD1938_DAC_4_CHANNELS << AD1938_DAC_CHAN_SHFT;
 162                 adc_reg |= AD1938_ADC_4_CHANNELS << AD1938_ADC_CHAN_SHFT;
 163                 break;
 164         case 8:
 165                 dac_reg |= AD1938_DAC_8_CHANNELS << AD1938_DAC_CHAN_SHFT;
 166                 adc_reg |= AD1938_ADC_8_CHANNELS << AD1938_ADC_CHAN_SHFT;
 167                 break;
 168         case 16:
 169                 dac_reg |= AD1938_DAC_16_CHANNELS << AD1938_DAC_CHAN_SHFT;
 170                 adc_reg |= AD1938_ADC_16_CHANNELS << AD1938_ADC_CHAN_SHFT;
 171                 break;
 172         default:
 173                 return -EINVAL;
 174         }
 175
 176         snd_soc_write(codec, AD1938_DAC_CTRL1, dac_reg);
 177         snd_soc_write(codec, AD1938_ADC_CTRL2, adc_reg);
 178
 179         return 0;
 180 }
 181
 182 static int ad1938_set_dai_fmt(struct snd_soc_dai *codec_dai,
 183                 unsigned int fmt)
 184 {
 185         struct snd_soc_codec *codec = codec_dai->codec;
 186         int adc_reg, dac_reg;
 187
 188         adc_reg = snd_soc_read(codec, AD1938_ADC_CTRL2);
 189         dac_reg = snd_soc_read(codec, AD1938_DAC_CTRL1);
 190
 191         /* At present, the driver only support AUX ADC mode(SND_SOC_DAIFMT_I2S
 192          * with TDM) and ADC&DAC TDM mode(SND_SOC_DAIFMT_DSP_A)
 193          */
 194         switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
 195         case SND_SOC_DAIFMT_I2S:
 196                 adc_reg &= ~AD1938_ADC_SERFMT_MASK;
 197                 adc_reg |= AD1938_ADC_SERFMT_TDM;
 198                 break;
 199         case SND_SOC_DAIFMT_DSP_A:
 200                 adc_reg &= ~AD1938_ADC_SERFMT_MASK;
 201                 adc_reg |= AD1938_ADC_SERFMT_AUX;
 202                 break;
 203         default:
 204                 return -EINVAL;
 205         }
 206
 207         switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
 208         case SND_SOC_DAIFMT_NB_NF: /* normal bit clock + frame */
 209                 adc_reg &= ~AD1938_ADC_LEFT_HIGH;
 210                 adc_reg &= ~AD1938_ADC_BCLK_INV;
 211                 dac_reg &= ~AD1938_DAC_LEFT_HIGH;
 212                 dac_reg &= ~AD1938_DAC_BCLK_INV;
 213                 break;
 214         case SND_SOC_DAIFMT_NB_IF: /* normal bclk + invert frm */
 215                 adc_reg |= AD1938_ADC_LEFT_HIGH;
 216                 adc_reg &= ~AD1938_ADC_BCLK_INV;
 217                 dac_reg |= AD1938_DAC_LEFT_HIGH;
 218                 dac_reg &= ~AD1938_DAC_BCLK_INV;
 219                 break;
 220         case SND_SOC_DAIFMT_IB_NF: /* invert bclk + normal frm */
 221                 adc_reg &= ~AD1938_ADC_LEFT_HIGH;
 222                 adc_reg |= AD1938_ADC_BCLK_INV;
 223                 dac_reg &= ~AD1938_DAC_LEFT_HIGH;
 224                 dac_reg |= AD1938_DAC_BCLK_INV;
 225                 break;
 226
 227         case SND_SOC_DAIFMT_IB_IF: /* invert bclk + frm */
 228                 adc_reg |= AD1938_ADC_LEFT_HIGH;
 229                 adc_reg |= AD1938_ADC_BCLK_INV;
 230                 dac_reg |= AD1938_DAC_LEFT_HIGH;
 231                 dac_reg |= AD1938_DAC_BCLK_INV;
 232                 break;
 233         default:
 234                 return -EINVAL;
 235         }
 236
 237         switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
 238         case SND_SOC_DAIFMT_CBM_CFM: /* codec clk & frm master */
 239                 adc_reg |= AD1938_ADC_LCR_MASTER;
 240                 adc_reg |= AD1938_ADC_BCLK_MASTER;
 241                 dac_reg |= AD1938_DAC_LCR_MASTER;
 242                 dac_reg |= AD1938_DAC_BCLK_MASTER;
 243                 break;
 244         case SND_SOC_DAIFMT_CBS_CFM: /* codec clk slave & frm master */
 245                 adc_reg |= AD1938_ADC_LCR_MASTER;
 246                 adc_reg &= ~AD1938_ADC_BCLK_MASTER;
 247                 dac_reg |= AD1938_DAC_LCR_MASTER;
 248                 dac_reg &= ~AD1938_DAC_BCLK_MASTER;
 249                 break;
 250         case SND_SOC_DAIFMT_CBM_CFS: /* codec clk master & frame slave */
 251                 adc_reg &= ~AD1938_ADC_LCR_MASTER;
 252                 adc_reg |= AD1938_ADC_BCLK_MASTER;
 253                 dac_reg &= ~AD1938_DAC_LCR_MASTER;
 254                 dac_reg |= AD1938_DAC_BCLK_MASTER;
 255                 break;
 256         case SND_SOC_DAIFMT_CBS_CFS: /* codec clk & frm slave */
 257                 adc_reg &= ~AD1938_ADC_LCR_MASTER;
 258                 adc_reg &= ~AD1938_ADC_BCLK_MASTER;
 259                 dac_reg &= ~AD1938_DAC_LCR_MASTER;
 260                 dac_reg &= ~AD1938_DAC_BCLK_MASTER;
 261                 break;
 262         default:
 263                 return -EINVAL;
 264         }
 265
 266         snd_soc_write(codec, AD1938_ADC_CTRL2, adc_reg);
 267         snd_soc_write(codec, AD1938_DAC_CTRL1, dac_reg);
 268
 269         return 0;
 270 }
 271
 272 static int ad1938_hw_params(struct snd_pcm_substream *substream,
 273                 struct snd_pcm_hw_params *params,
 274                 struct snd_soc_dai *dai)
 275 {
 276         int word_len = 0, reg = 0;
 277
 278         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 279         struct snd_soc_device *socdev = rtd->socdev;
 280         struct snd_soc_codec *codec = socdev->card->codec;
 281
 282         /* bit size */
 283         switch (params_format(params)) {
 284         case SNDRV_PCM_FORMAT_S16_LE:
 285                 word_len = 3;
 286                 break;
 287         case SNDRV_PCM_FORMAT_S20_3LE:
 288                 word_len = 1;
 289                 break;
 290         case SNDRV_PCM_FORMAT_S24_LE:
 291         case SNDRV_PCM_FORMAT_S32_LE:
 292                 word_len = 0;
 293                 break;
 294         }
 295
 296         reg = snd_soc_read(codec, AD1938_DAC_CTRL2);
 297         reg = (reg & (~AD1938_DAC_WORD_LEN_MASK)) | word_len;
 298         snd_soc_write(codec, AD1938_DAC_CTRL2, reg);
 299
 300         reg = snd_soc_read(codec, AD1938_ADC_CTRL1);
 301         reg = (reg & (~AD1938_ADC_WORD_LEN_MASK)) | word_len;
 302         snd_soc_write(codec, AD1938_ADC_CTRL1, reg);
 303
 304         return 0;
 305 }
 306
 307 static int __devinit ad1938_spi_probe(struct spi_device *spi)
 308 {
 309         struct snd_soc_codec *codec;
 310         struct ad1938_priv *ad1938;
 311
 312         ad1938 = kzalloc(sizeof(struct ad1938_priv), GFP_KERNEL);
 313         if (ad1938 == NULL)
 314                 return -ENOMEM;
 315
 316         codec = &ad1938->codec;
 317         codec->control_data = spi;
 318         codec->dev = &spi->dev;
 319
 320         dev_set_drvdata(&spi->dev, ad1938);
 321
 322         return ad1938_register(ad1938);
 323 }
 324
 325 static int __devexit ad1938_spi_remove(struct spi_device *spi)
 326 {
 327         struct ad1938_priv *ad1938 = dev_get_drvdata(&spi->dev);
 328
 329         ad1938_unregister(ad1938);
 330         return 0;
 331 }
 332
 333 static struct spi_driver ad1938_spi_driver = {
 334         .driver = {
 335                 .name   = "ad1938",
 336                 .owner  = THIS_MODULE,
 337         },
 338         .probe          = ad1938_spi_probe,
 339         .remove         = __devexit_p(ad1938_spi_remove),
 340 };
 341
 342 static struct snd_soc_dai_ops ad1938_dai_ops = {
 343         .hw_params = ad1938_hw_params,
 344         .digital_mute = ad1938_mute,
 345         .set_tdm_slot = ad1938_set_tdm_slot,
 346         .set_fmt = ad1938_set_dai_fmt,
 347 };
 348
 349 /* codec DAI instance */
 350 struct snd_soc_dai ad1938_dai = {
 351         .name = "AD1938",
 352         .playback = {
 353                 .stream_name = "Playback",
 354                 .channels_min = 2,
 355                 .channels_max = 8,
 356                 .rates = SNDRV_PCM_RATE_48000,
 357                 .formats = SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S16_LE |
 358                         SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S24_LE,
 359         },
 360         .capture = {
 361                 .stream_name = "Capture",
 362                 .channels_min = 2,
 363                 .channels_max = 4,
 364                 .rates = SNDRV_PCM_RATE_48000,
 365                 .formats = SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S16_LE |
 366                         SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S24_LE,
 367         },
 368         .ops = &ad1938_dai_ops,
 369 };
 370 EXPORT_SYMBOL_GPL(ad1938_dai);
 371
 372 static int ad1938_register(struct ad1938_priv *ad1938)
 373 {
 374         int ret;
 375         struct snd_soc_codec *codec = &ad1938->codec;
 376
 377         if (ad1938_codec) {
 378                 dev_err(codec->dev, "Another ad1938 is registered\n");
 379                 return -EINVAL;
 380         }
 381
 382         mutex_init(&codec->mutex);
 383         INIT_LIST_HEAD(&codec->dapm_widgets);
 384         INIT_LIST_HEAD(&codec->dapm_paths);
 385         codec->private_data = ad1938;
 386         codec->reg_cache = ad1938->reg_cache;
 387         codec->reg_cache_size = AD1938_NUM_REGS;
 388         codec->name = "AD1938";
 389         codec->owner = THIS_MODULE;
 390         codec->dai = &ad1938_dai;
 391         codec->num_dai = 1;
 392         INIT_LIST_HEAD(&codec->dapm_widgets);
 393         INIT_LIST_HEAD(&codec->dapm_paths);
 394
 395         ad1938_dai.dev = codec->dev;
 396         ad1938_codec = codec;
 397
 398         memcpy(codec->reg_cache, ad1938_reg, AD1938_NUM_REGS);
 399
 400         ret = snd_soc_codec_set_cache_io(codec, 16, 8, SND_SOC_SPI);
 401         if (ret < 0) {
 402                 dev_err(codec->dev, "failed to set cache I/O: %d\n",
 403                                 ret);
 404                 kfree(ad1938);
 405                 return ret;
 406         }
 407
 408         /* default setting for ad1938 */
 409
 410         /* unmute dac channels */
 411         snd_soc_write(codec, AD1938_DAC_CHNL_MUTE, 0x0);
 412         /* de-emphasis: 48kHz, powedown dac */
 413         snd_soc_write(codec, AD1938_DAC_CTRL2, 0x1A);
 414         /* powerdown dac, dac in tdm mode */
 415         snd_soc_write(codec, AD1938_DAC_CTRL0, 0x41);
 416         /* high-pass filter enable */
 417         snd_soc_write(codec, AD1938_ADC_CTRL0, 0x3);
 418         /* sata delay=1, adc aux mode */
 419         snd_soc_write(codec, AD1938_ADC_CTRL1, 0x43);
 420         /* pll input: mclki/xi */
 421         snd_soc_write(codec, AD1938_PLL_CLK_CTRL0, 0x9D);
 422         snd_soc_write(codec, AD1938_PLL_CLK_CTRL1, 0x04);
 423
 424         ret = snd_soc_register_codec(codec);
 425         if (ret != 0) {
 426                 dev_err(codec->dev, "Failed to register codec: %d\n", ret);
 427                 kfree(ad1938);
 428                 return ret;
 429         }
 430
 431         ret = snd_soc_register_dai(&ad1938_dai);
 432         if (ret != 0) {
 433                 dev_err(codec->dev, "Failed to register DAI: %d\n", ret);
 434                 snd_soc_unregister_codec(codec);
 435                 kfree(ad1938);
 436                 return ret;
 437         }
 438
 439         return 0;
 440 }
 441
 442 static void ad1938_unregister(struct ad1938_priv *ad1938)
 443 {
 444         snd_soc_unregister_dai(&ad1938_dai);
 445         snd_soc_unregister_codec(&ad1938->codec);
 446         kfree(ad1938);
 447         ad1938_codec = NULL;
 448 }
 449
 450 static int ad1938_probe(struct platform_device *pdev)
 451 {
 452         struct snd_soc_device *socdev = platform_get_drvdata(pdev);
 453         struct snd_soc_codec *codec;
 454         int ret = 0;
 455
 456         if (ad1938_codec == NULL) {
 457                 dev_err(&pdev->dev, "Codec device not registered\n");
 458                 return -ENODEV;
 459         }
 460
 461         socdev->card->codec = ad1938_codec;
 462         codec = ad1938_codec;
 463
 464         /* register pcms */
 465         ret = snd_soc_new_pcms(socdev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1);
 466         if (ret < 0) {
 467                 dev_err(codec->dev, "failed to create pcms: %d\n", ret);
 468                 goto pcm_err;
 469         }
 470
 471         snd_soc_add_controls(codec, ad1938_snd_controls,
 472                              ARRAY_SIZE(ad1938_snd_controls));
 473         snd_soc_dapm_new_controls(codec, ad1938_dapm_widgets,
 474                                   ARRAY_SIZE(ad1938_dapm_widgets));
 475         snd_soc_dapm_add_routes(codec, audio_paths, ARRAY_SIZE(audio_paths));
 476
 477
 478 pcm_err:
 479         return ret;
 480 }
 481
 482 /* power down chip */
 483 static int ad1938_remove(struct platform_device *pdev)
 484 {
 485         struct snd_soc_device *socdev = platform_get_drvdata(pdev);
 486
 487         snd_soc_free_pcms(socdev);
 488         snd_soc_dapm_free(socdev);
 489
 490         return 0;
 491 }
 492
 493 struct snd_soc_codec_device soc_codec_dev_ad1938 = {
 494         .probe =        ad1938_probe,
 495         .remove =       ad1938_remove,
 496 };
 497 EXPORT_SYMBOL_GPL(soc_codec_dev_ad1938);
 498
 499 static int __init ad1938_init(void)
 500 {
 501         int ret;
 502
 503         ret = spi_register_driver(&ad1938_spi_driver);
 504         if (ret != 0) {
 505                 printk(KERN_ERR "Failed to register ad1938 SPI driver: %d\n",
 506                                 ret);
 507         }
 508
 509         return ret;
 510 }
 511 module_init(ad1938_init);
 512
 513 static void __exit ad1938_exit(void)
 514 {
 515         spi_unregister_driver(&ad1938_spi_driver);
 516 }
 517 module_exit(ad1938_exit);
 518
 519 MODULE_DESCRIPTION("ASoC ad1938 driver");
 520 MODULE_AUTHOR("Barry Song ");
 521 MODULE_LICENSE("GPL");