sound/soc/codecs/cs4270.c

   1 /*
   2  * CS4270 ALSA SoC (ASoC) codec driver
   3  *
   4  * Author: Timur Tabi <timur@freescale.com>
   5  *
   6  * Copyright 2007 Freescale Semiconductor, Inc.  This file is licensed under
   7  * the terms of the GNU General Public License version 2.  This program
   8  * is licensed "as is" without any warranty of any kind, whether express
   9  * or implied.
  10  *
  11  * This is an ASoC device driver for the Cirrus Logic CS4270 codec.
  12  *
  13  * Current features/limitations:
  14  *
  15  * 1) Software mode is supported.  Stand-alone mode is not supported.
  16  * 2) Only I2C is supported, not SPI
  17  * 3) Only Master mode is supported, not Slave.
  18  * 4) The machine driver's 'startup' function must call
  19  *    cs4270_set_dai_sysclk() with the value of MCLK.
  20  * 5) Only I2S and left-justified modes are supported
  21  * 6) Power management is not supported
  22  * 7) The only supported control is volume and hardware mute (if enabled)
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/platform_device.h>
  27 #include <sound/core.h>
  28 #include <sound/soc.h>
  29 #include <sound/initval.h>
  30 #include <linux/i2c.h>
  31
  32 #include "cs4270.h"
  33
  34 /*
  35  * The codec isn't really big-endian or little-endian, since the I2S
  36  * interface requires data to be sent serially with the MSbit first.
  37  * However, to support BE and LE I2S devices, we specify both here.  That
  38  * way, ALSA will always match the bit patterns.
  39  */
  40 #define CS4270_FORMATS (SNDRV_PCM_FMTBIT_S8      | \
  41                         SNDRV_PCM_FMTBIT_S16_LE  | SNDRV_PCM_FMTBIT_S16_BE  | \
  42                         SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S18_3BE | \
  43                         SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S20_3BE | \
  44                         SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE | \
  45                         SNDRV_PCM_FMTBIT_S24_LE  | SNDRV_PCM_FMTBIT_S24_BE)
  46
  47 /* CS4270 registers addresses */
  48 #define CS4270_CHIPID   0x01    /* Chip ID */
  49 #define CS4270_PWRCTL   0x02    /* Power Control */
  50 #define CS4270_MODE     0x03    /* Mode Control */
  51 #define CS4270_FORMAT   0x04    /* Serial Format, ADC/DAC Control */
  52 #define CS4270_TRANS    0x05    /* Transition Control */
  53 #define CS4270_MUTE     0x06    /* Mute Control */
  54 #define CS4270_VOLA     0x07    /* DAC Channel A Volume Control */
  55 #define CS4270_VOLB     0x08    /* DAC Channel B Volume Control */
  56
  57 #define CS4270_FIRSTREG 0x01
  58 #define CS4270_LASTREG  0x08
  59 #define CS4270_NUMREGS  (CS4270_LASTREG - CS4270_FIRSTREG + 1)
  60
  61 /* Bit masks for the CS4270 registers */
  62 #define CS4270_CHIPID_ID        0xF0
  63 #define CS4270_CHIPID_REV       0x0F
  64 #define CS4270_PWRCTL_FREEZE    0x80
  65 #define CS4270_PWRCTL_PDN_ADC   0x20
  66 #define CS4270_PWRCTL_PDN_DAC   0x02
  67 #define CS4270_PWRCTL_PDN       0x01
  68 #define CS4270_MODE_SPEED_MASK  0x30
  69 #define CS4270_MODE_1X          0x00
  70 #define CS4270_MODE_2X          0x10
  71 #define CS4270_MODE_4X          0x20
  72 #define CS4270_MODE_SLAVE       0x30
  73 #define CS4270_MODE_DIV_MASK    0x0E
  74 #define CS4270_MODE_DIV1        0x00
  75 #define CS4270_MODE_DIV15       0x02
  76 #define CS4270_MODE_DIV2        0x04
  77 #define CS4270_MODE_DIV3        0x06
  78 #define CS4270_MODE_DIV4        0x08
  79 #define CS4270_MODE_POPGUARD    0x01
  80 #define CS4270_FORMAT_FREEZE_A  0x80
  81 #define CS4270_FORMAT_FREEZE_B  0x40
  82 #define CS4270_FORMAT_LOOPBACK  0x20
  83 #define CS4270_FORMAT_DAC_MASK  0x18
  84 #define CS4270_FORMAT_DAC_LJ    0x00
  85 #define CS4270_FORMAT_DAC_I2S   0x08
  86 #define CS4270_FORMAT_DAC_RJ16  0x18
  87 #define CS4270_FORMAT_DAC_RJ24  0x10
  88 #define CS4270_FORMAT_ADC_MASK  0x01
  89 #define CS4270_FORMAT_ADC_LJ    0x00
  90 #define CS4270_FORMAT_ADC_I2S   0x01
  91 #define CS4270_TRANS_ONE_VOL    0x80
  92 #define CS4270_TRANS_SOFT       0x40
  93 #define CS4270_TRANS_ZERO       0x20
  94 #define CS4270_TRANS_INV_ADC_A  0x08
  95 #define CS4270_TRANS_INV_ADC_B  0x10
  96 #define CS4270_TRANS_INV_DAC_A  0x02
  97 #define CS4270_TRANS_INV_DAC_B  0x04
  98 #define CS4270_TRANS_DEEMPH     0x01
  99 #define CS4270_MUTE_AUTO        0x20
 100 #define CS4270_MUTE_ADC_A       0x08
 101 #define CS4270_MUTE_ADC_B       0x10
 102 #define CS4270_MUTE_POLARITY    0x04
 103 #define CS4270_MUTE_DAC_A       0x01
 104 #define CS4270_MUTE_DAC_B       0x02
 105
 106 /* Private data for the CS4270 */
 107 struct cs4270_private {
 108         struct snd_soc_codec codec;
 109         u8 reg_cache[CS4270_NUMREGS];
 110         unsigned int mclk; /* Input frequency of the MCLK pin */
 111         unsigned int mode; /* The mode (I2S or left-justified) */
 112 };
 113
 114 /*
 115  * Clock Ratio Selection for Master Mode with I2C enabled
 116  *
 117  * The data for this chart is taken from Table 5 of the CS4270 reference
 118  * manual.
 119  *
 120  * This table is used to determine how to program the Mode Control register.
 121  * It is also used by cs4270_set_dai_sysclk() to tell ALSA which sampling
 122  * rates the CS4270 currently supports.
 123  *
 124  * Each element in this array corresponds to the ratios in mclk_ratios[].
 125  * These two arrays need to be in sync.
 126  *
 127  * 'speed_mode' is the corresponding bit pattern to be written to the
 128  * MODE bits of the Mode Control Register
 129  *
 130  * 'mclk' is the corresponding bit pattern to be wirten to the MCLK bits of
 131  * the Mode Control Register.
 132  *
 133  * In situations where a single ratio is represented by multiple speed
 134  * modes, we favor the slowest speed.  E.g, for a ratio of 128, we pick
 135  * double-speed instead of quad-speed.  However, the CS4270 errata states
 136  * that Divide-By-1.5 can cause failures, so we avoid that mode where
 137  * possible.
 138  *
 139  * ERRATA: There is an errata for the CS4270 where divide-by-1.5 does not
 140  * work if VD = 3.3V.  If this effects you, select the
 141  * CONFIG_SND_SOC_CS4270_VD33_ERRATA Kconfig option, and the driver will
 142  * never select any sample rates that require divide-by-1.5.
 143  */
 144 static struct {
 145         unsigned int ratio;
 146         u8 speed_mode;
 147         u8 mclk;
 148 } cs4270_mode_ratios[] = {
 149         {64, CS4270_MODE_4X, CS4270_MODE_DIV1},
 150 #ifndef CONFIG_SND_SOC_CS4270_VD33_ERRATA
 151         {96, CS4270_MODE_4X, CS4270_MODE_DIV15},
 152 #endif
 153         {128, CS4270_MODE_2X, CS4270_MODE_DIV1},
 154         {192, CS4270_MODE_4X, CS4270_MODE_DIV3},
 155         {256, CS4270_MODE_1X, CS4270_MODE_DIV1},
 156         {384, CS4270_MODE_2X, CS4270_MODE_DIV3},
 157         {512, CS4270_MODE_1X, CS4270_MODE_DIV2},
 158         {768, CS4270_MODE_1X, CS4270_MODE_DIV3},
 159         {1024, CS4270_MODE_1X, CS4270_MODE_DIV4}
 160 };
 161
 162 /* The number of MCLK/LRCK ratios supported by the CS4270 */
 163 #define NUM_MCLK_RATIOS         ARRAY_SIZE(cs4270_mode_ratios)
 164
 165 /*
 166  * Determine the CS4270 samples rates.
 167  *
 168  * 'freq' is the input frequency to MCLK.  The other parameters are ignored.
 169  *
 170  * The value of MCLK is used to determine which sample rates are supported
 171  * by the CS4270.  The ratio of MCLK / Fs must be equal to one of nine
 172  * support values: 64, 96, 128, 192, 256, 384, 512, 768, and 1024.
 173  *
 174  * This function calculates the nine ratios and determines which ones match
 175  * a standard sample rate.  If there's a match, then it is added to the list
 176  * of support sample rates.
 177  *
 178  * This function must be called by the machine driver's 'startup' function,
 179  * otherwise the list of supported sample rates will not be available in
 180  * time for ALSA.
 181  *
 182  * Note that in stand-alone mode, the sample rate is determined by input
 183  * pins M0, M1, MDIV1, and MDIV2.  Also in stand-alone mode, divide-by-3
 184  * is not a programmable option.  However, divide-by-3 is not an available
 185  * option in stand-alone mode.  This cases two problems: a ratio of 768 is
 186  * not available (it requires divide-by-3) and B) ratios 192 and 384 can
 187  * only be selected with divide-by-1.5, but there is an errate that make
 188  * this selection difficult.
 189  *
 190  * In addition, there is no mechanism for communicating with the machine
 191  * driver what the input settings can be.  This would need to be implemented
 192  * for stand-alone mode to work.
 193  */
 194 static int cs4270_set_dai_sysclk(struct snd_soc_dai *codec_dai,
 195                                  int clk_id, unsigned int freq, int dir)
 196 {
 197         struct snd_soc_codec *codec = codec_dai->codec;
 198         struct cs4270_private *cs4270 = codec->private_data;
 199         unsigned int rates = 0;
 200         unsigned int rate_min = -1;
 201         unsigned int rate_max = 0;
 202         unsigned int i;
 203
 204         cs4270->mclk = freq;
 205
 206         for (i = 0; i < NUM_MCLK_RATIOS; i++) {
 207                 unsigned int rate = freq / cs4270_mode_ratios[i].ratio;
 208                 rates |= snd_pcm_rate_to_rate_bit(rate);
 209                 if (rate < rate_min)
 210                         rate_min = rate;
 211                 if (rate > rate_max)
 212                         rate_max = rate;
 213         }
 214         /* FIXME: soc should support a rate list */
 215         rates &= ~SNDRV_PCM_RATE_KNOT;
 216
 217         if (!rates) {
 218                 printk(KERN_ERR "cs4270: could not find a valid sample rate\n");
 219                 return -EINVAL;
 220         }
 221
 222         codec_dai->playback.rates = rates;
 223         codec_dai->playback.rate_min = rate_min;
 224         codec_dai->playback.rate_max = rate_max;
 225
 226         codec_dai->capture.rates = rates;
 227         codec_dai->capture.rate_min = rate_min;
 228         codec_dai->capture.rate_max = rate_max;
 229
 230         return 0;
 231 }
 232
 233 /*
 234  * Configure the codec for the selected audio format
 235  *
 236  * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the
 237  * codec accordingly.
 238  *
 239  * Currently, this function only supports SND_SOC_DAIFMT_I2S and
 240  * SND_SOC_DAIFMT_LEFT_J.  The CS4270 codec also supports right-justified
 241  * data for playback only, but ASoC currently does not support different
 242  * formats for playback vs. record.
 243  */
 244 static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai,
 245                               unsigned int format)
 246 {
 247         struct snd_soc_codec *codec = codec_dai->codec;
 248         struct cs4270_private *cs4270 = codec->private_data;
 249         int ret = 0;
 250
 251         switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
 252         case SND_SOC_DAIFMT_I2S:
 253         case SND_SOC_DAIFMT_LEFT_J:
 254                 cs4270->mode = format & SND_SOC_DAIFMT_FORMAT_MASK;
 255                 break;
 256         default:
 257                 printk(KERN_ERR "cs4270: invalid DAI format\n");
 258                 ret = -EINVAL;
 259         }
 260
 261         return ret;
 262 }
 263
 264 /*
 265  * Pre-fill the CS4270 register cache.
 266  *
 267  * We use the auto-increment feature of the CS4270 to read all registers in
 268  * one shot.
 269  */
 270 static int cs4270_fill_cache(struct snd_soc_codec *codec)
 271 {
 272         u8 *cache = codec->reg_cache;
 273         struct i2c_client *i2c_client = codec->control_data;
 274         s32 length;
 275
 276         length = i2c_smbus_read_i2c_block_data(i2c_client,
 277                 CS4270_FIRSTREG | 0x80, CS4270_NUMREGS, cache);
 278
 279         if (length != CS4270_NUMREGS) {
 280                 printk(KERN_ERR "cs4270: I2C read failure, addr=0x%x\n",
 281                        i2c_client->addr);
 282                 return -EIO;
 283         }
 284
 285         return 0;
 286 }
 287
 288 /*
 289  * Read from the CS4270 register cache.
 290  *
 291  * This CS4270 registers are cached to avoid excessive I2C I/O operations.
 292  * After the initial read to pre-fill the cache, the CS4270 never updates
 293  * the register values, so we won't have a cache coherncy problem.
 294  */
 295 static unsigned int cs4270_read_reg_cache(struct snd_soc_codec *codec,
 296         unsigned int reg)
 297 {
 298         u8 *cache = codec->reg_cache;
 299
 300         if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
 301                 return -EIO;
 302
 303         return cache[reg - CS4270_FIRSTREG];
 304 }
 305
 306 /*
 307  * Write to a CS4270 register via the I2C bus.
 308  *
 309  * This function writes the given value to the given CS4270 register, and
 310  * also updates the register cache.
 311  *
 312  * Note that we don't use the hw_write function pointer of snd_soc_codec.
 313  * That's because it's too clunky: the hw_write_t prototype does not match
 314  * i2c_smbus_write_byte_data(), and it's just another layer of overhead.
 315  */
 316 static int cs4270_i2c_write(struct snd_soc_codec *codec, unsigned int reg,
 317                             unsigned int value)
 318 {
 319         u8 *cache = codec->reg_cache;
 320
 321         if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
 322                 return -EIO;
 323
 324         /* Only perform an I2C operation if the new value is different */
 325         if (cache[reg - CS4270_FIRSTREG] != value) {
 326                 struct i2c_client *client = codec->control_data;
 327                 if (i2c_smbus_write_byte_data(client, reg, value)) {
 328                         printk(KERN_ERR "cs4270: I2C write failed\n");
 329                         return -EIO;
 330                 }
 331
 332                 /* We've written to the hardware, so update the cache */
 333                 cache[reg - CS4270_FIRSTREG] = value;
 334         }
 335
 336         return 0;
 337 }
 338
 339 /*
 340  * Program the CS4270 with the given hardware parameters.
 341  *
 342  * The .ops functions are used to provide board-specific data, like
 343  * input frequencies, to this driver.  This function takes that information,
 344  * combines it with the hardware parameters provided, and programs the
 345  * hardware accordingly.
 346  */
 347 static int cs4270_hw_params(struct snd_pcm_substream *substream,
 348                             struct snd_pcm_hw_params *params,
 349                             struct snd_soc_dai *dai)
 350 {
 351         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 352         struct snd_soc_device *socdev = rtd->socdev;
 353         struct snd_soc_codec *codec = socdev->codec;
 354         struct cs4270_private *cs4270 = codec->private_data;
 355         int ret;
 356         unsigned int i;
 357         unsigned int rate;
 358         unsigned int ratio;
 359         int reg;
 360
 361         /* Figure out which MCLK/LRCK ratio to use */
 362
 363         rate = params_rate(params);     /* Sampling rate, in Hz */
 364         ratio = cs4270->mclk / rate;    /* MCLK/LRCK ratio */
 365
 366         for (i = 0; i < NUM_MCLK_RATIOS; i++) {
 367                 if (cs4270_mode_ratios[i].ratio == ratio)
 368                         break;
 369         }
 370
 371         if (i == NUM_MCLK_RATIOS) {
 372                 /* We did not find a matching ratio */
 373                 printk(KERN_ERR "cs4270: could not find matching ratio\n");
 374                 return -EINVAL;
 375         }
 376
 377         /* Freeze and power-down the codec */
 378
 379         ret = snd_soc_write(codec, CS4270_PWRCTL, CS4270_PWRCTL_FREEZE |
 380                             CS4270_PWRCTL_PDN_ADC | CS4270_PWRCTL_PDN_DAC |
 381                             CS4270_PWRCTL_PDN);
 382         if (ret < 0) {
 383                 printk(KERN_ERR "cs4270: I2C write failed\n");
 384                 return ret;
 385         }
 386
 387         /* Program the mode control register */
 388
 389         reg = snd_soc_read(codec, CS4270_MODE);
 390         reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK);
 391         reg |= cs4270_mode_ratios[i].speed_mode | cs4270_mode_ratios[i].mclk;
 392
 393         ret = snd_soc_write(codec, CS4270_MODE, reg);
 394         if (ret < 0) {
 395                 printk(KERN_ERR "cs4270: I2C write failed\n");
 396                 return ret;
 397         }
 398
 399         /* Program the format register */
 400
 401         reg = snd_soc_read(codec, CS4270_FORMAT);
 402         reg &= ~(CS4270_FORMAT_DAC_MASK | CS4270_FORMAT_ADC_MASK);
 403
 404         switch (cs4270->mode) {
 405         case SND_SOC_DAIFMT_I2S:
 406                 reg |= CS4270_FORMAT_DAC_I2S | CS4270_FORMAT_ADC_I2S;
 407                 break;
 408         case SND_SOC_DAIFMT_LEFT_J:
 409                 reg |= CS4270_FORMAT_DAC_LJ | CS4270_FORMAT_ADC_LJ;
 410                 break;
 411         default:
 412                 printk(KERN_ERR "cs4270: unknown format\n");
 413                 return -EINVAL;
 414         }
 415
 416         ret = snd_soc_write(codec, CS4270_FORMAT, reg);
 417         if (ret < 0) {
 418                 printk(KERN_ERR "cs4270: I2C write failed\n");
 419                 return ret;
 420         }
 421
 422         /* Disable auto-mute.  This feature appears to be buggy, because in
 423            some situations, auto-mute will not deactivate when it should. */
 424
 425         reg = snd_soc_read(codec, CS4270_MUTE);
 426         reg &= ~CS4270_MUTE_AUTO;
 427         ret = snd_soc_write(codec, CS4270_MUTE, reg);
 428         if (ret < 0) {
 429                 printk(KERN_ERR "cs4270: I2C write failed\n");
 430                 return ret;
 431         }
 432
 433         /* Disable automatic volume control.  It's enabled by default, and
 434          * it causes volume change commands to be delayed, sometimes until
 435          * after playback has started.
 436          */
 437
 438         reg = cs4270_read_reg_cache(codec, CS4270_TRANS);
 439         reg &= ~(CS4270_TRANS_SOFT | CS4270_TRANS_ZERO);
 440         ret = cs4270_i2c_write(codec, CS4270_TRANS, reg);
 441         if (ret < 0) {
 442                 printk(KERN_ERR "I2C write failed\n");
 443                 return ret;
 444         }
 445
 446         /* Thaw and power-up the codec */
 447
 448         ret = snd_soc_write(codec, CS4270_PWRCTL, 0);
 449         if (ret < 0) {
 450                 printk(KERN_ERR "cs4270: I2C write failed\n");
 451                 return ret;
 452         }
 453
 454         return ret;
 455 }
 456
 457 #ifdef CONFIG_SND_SOC_CS4270_HWMUTE
 458 /*
 459  * Set the CS4270 external mute
 460  *
 461  * This function toggles the mute bits in the MUTE register.  The CS4270's
 462  * mute capability is intended for external muting circuitry, so if the
 463  * board does not have the MUTEA or MUTEB pins connected to such circuitry,
 464  * then this function will do nothing.
 465  */
 466 static int cs4270_mute(struct snd_soc_dai *dai, int mute)
 467 {
 468         struct snd_soc_codec *codec = dai->codec;
 469         int reg6;
 470
 471         reg6 = snd_soc_read(codec, CS4270_MUTE);
 472
 473         if (mute)
 474                 reg6 |= CS4270_MUTE_ADC_A | CS4270_MUTE_ADC_B |
 475                         CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B;
 476         else
 477                 reg6 &= ~(CS4270_MUTE_ADC_A | CS4270_MUTE_ADC_B |
 478                           CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B);
 479
 480         return snd_soc_write(codec, CS4270_MUTE, reg6);
 481 }
 482 #else
 483 #define cs4270_mute NULL
 484 #endif
 485
 486 /* A list of non-DAPM controls that the CS4270 supports */
 487 static const struct snd_kcontrol_new cs4270_snd_controls[] = {
 488         SOC_DOUBLE_R("Master Playback Volume",
 489                 CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 1)
 490 };
 491
 492 /*
 493  * Global variable to store socdev for i2c probe function.
 494  *
 495  * If struct i2c_driver had a private_data field, we wouldn't need to use
 496  * cs4270_socdec.  This is the only way to pass the socdev structure to
 497  * cs4270_i2c_probe().
 498  *
 499  * The real solution to cs4270_socdev is to create a mechanism
 500  * that maps I2C addresses to snd_soc_device structures.  Perhaps the
 501  * creation of the snd_soc_device object should be moved out of
 502  * cs4270_probe() and into cs4270_i2c_probe(), but that would make this
 503  * driver dependent on I2C.  The CS4270 supports "stand-alone" mode, whereby
 504  * the chip is *not* connected to the I2C bus, but is instead configured via
 505  * input pins.
 506  */
 507 static struct snd_soc_device *cs4270_socdev;
 508
 509 struct snd_soc_dai cs4270_dai = {
 510         .name = "cs4270",
 511         .playback = {
 512                 .stream_name = "Playback",
 513                 .channels_min = 1,
 514                 .channels_max = 2,
 515                 .rates = 0,
 516                 .formats = CS4270_FORMATS,
 517         },
 518         .capture = {
 519                 .stream_name = "Capture",
 520                 .channels_min = 1,
 521                 .channels_max = 2,
 522                 .rates = 0,
 523                 .formats = CS4270_FORMATS,
 524         },
 525         .ops = {
 526                 .hw_params = cs4270_hw_params,
 527                 .set_sysclk = cs4270_set_dai_sysclk,
 528                 .set_fmt = cs4270_set_dai_fmt,
 529                 .digital_mute = cs4270_mute,
 530         },
 531 };
 532 EXPORT_SYMBOL_GPL(cs4270_dai);
 533
 534 /*
 535  * Initialize the I2C interface of the CS4270
 536  *
 537  * This function is called for whenever the I2C subsystem finds a device
 538  * at a particular address.
 539  *
 540  * Note: snd_soc_new_pcms() must be called before this function can be called,
 541  * because of snd_ctl_add().
 542  */
 543 static int cs4270_i2c_probe(struct i2c_client *i2c_client,
 544         const struct i2c_device_id *id)
 545 {
 546         struct snd_soc_device *socdev = cs4270_socdev;
 547         struct snd_soc_codec *codec;
 548         struct cs4270_private *cs4270;
 549         int i;
 550         int ret = 0;
 551
 552         /* Verify that we have a CS4270 */
 553
 554         ret = i2c_smbus_read_byte_data(i2c_client, CS4270_CHIPID);
 555         if (ret < 0) {
 556                 printk(KERN_ERR "cs4270: failed to read I2C\n");
 557                 return ret;
 558         }
 559         /* The top four bits of the chip ID should be 1100. */
 560         if ((ret & 0xF0) != 0xC0) {
 561                 printk(KERN_ERR "cs4270: device at addr %X is not a CS4270\n",
 562                        i2c_client->addr);
 563                 return -ENODEV;
 564         }
 565
 566         printk(KERN_INFO "cs4270: found device at I2C address %X\n",
 567                 i2c_client->addr);
 568         printk(KERN_INFO "cs4270: hardware revision %X\n", ret & 0xF);
 569
 570         /* Allocate enough space for the snd_soc_codec structure
 571            and our private data together. */
 572         cs4270 = kzalloc(sizeof(struct cs4270_private), GFP_KERNEL);
 573         if (!cs4270) {
 574                 printk(KERN_ERR "cs4270: Could not allocate codec structure\n");
 575                 return -ENOMEM;
 576         }
 577         codec = &cs4270->codec;
 578         socdev->codec = codec;
 579
 580         mutex_init(&codec->mutex);
 581         INIT_LIST_HEAD(&codec->dapm_widgets);
 582         INIT_LIST_HEAD(&codec->dapm_paths);
 583
 584         codec->name = "CS4270";
 585         codec->owner = THIS_MODULE;
 586         codec->dai = &cs4270_dai;
 587         codec->num_dai = 1;
 588         codec->private_data = cs4270;
 589         codec->control_data = i2c_client;
 590         codec->read = cs4270_read_reg_cache;
 591         codec->write = cs4270_i2c_write;
 592         codec->reg_cache = cs4270->reg_cache;
 593         codec->reg_cache_size = CS4270_NUMREGS;
 594
 595         /* The I2C interface is set up, so pre-fill our register cache */
 596
 597         ret = cs4270_fill_cache(codec);
 598         if (ret < 0) {
 599                 printk(KERN_ERR "cs4270: failed to fill register cache\n");
 600                 goto error_free_codec;
 601         }
 602
 603         /* Register PCMs */
 604
 605         ret = snd_soc_new_pcms(socdev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1);
 606         if (ret < 0) {
 607                 printk(KERN_ERR "cs4270: failed to create PCMs\n");
 608                 goto error_free_codec;
 609         }
 610
 611         /* Add the non-DAPM controls */
 612
 613         for (i = 0; i < ARRAY_SIZE(cs4270_snd_controls); i++) {
 614                 struct snd_kcontrol *kctrl;
 615
 616                 kctrl = snd_soc_cnew(&cs4270_snd_controls[i], codec, NULL);
 617                 if (!kctrl) {
 618                         printk(KERN_ERR "cs4270: error creating control '%s'\n",
 619                                cs4270_snd_controls[i].name);
 620                         ret = -ENOMEM;
 621                         goto error_free_pcms;
 622                 }
 623
 624                 ret = snd_ctl_add(codec->card, kctrl);
 625                 if (ret < 0) {
 626                         printk(KERN_ERR "cs4270: error adding control '%s'\n",
 627                                cs4270_snd_controls[i].name);
 628                         goto error_free_pcms;
 629                 }
 630         }
 631
 632         /* Initialize the SOC device */
 633
 634         ret = snd_soc_init_card(socdev);
 635         if (ret < 0) {
 636                 printk(KERN_ERR "cs4270: failed to register card\n");
 637                 goto error_free_pcms;;
 638         }
 639
 640         i2c_set_clientdata(i2c_client, socdev);
 641
 642         return 0;
 643
 644 error_free_pcms:
 645         snd_soc_free_pcms(socdev);
 646
 647 error_free_codec:
 648         kfree(cs4270);
 649
 650         return ret;
 651 }
 652
 653 static int cs4270_i2c_remove(struct i2c_client *i2c_client)
 654 {
 655         struct snd_soc_device *socdev = i2c_get_clientdata(i2c_client);
 656         struct snd_soc_codec *codec = socdev->codec;
 657         struct cs4270_private *cs4270 = codec->private_data;
 658
 659         snd_soc_free_pcms(socdev);
 660         kfree(cs4270);
 661
 662         return 0;
 663 }
 664
 665 static struct i2c_device_id cs4270_id[] = {
 666         {"cs4270", 0},
 667         {}
 668 };
 669 MODULE_DEVICE_TABLE(i2c, cs4270_id);
 670
 671 static struct i2c_driver cs4270_i2c_driver = {
 672         .driver = {
 673                 .name = "cs4270",
 674                 .owner = THIS_MODULE,
 675         },
 676         .id_table = cs4270_id,
 677         .probe = cs4270_i2c_probe,
 678         .remove = cs4270_i2c_remove,
 679 };
 680
 681 /*
 682  * ASoC probe function
 683  *
 684  * This function is called when the machine driver calls
 685  * platform_device_add().
 686  */
 687 static int cs4270_probe(struct platform_device *pdev)
 688 {
 689         cs4270_socdev = platform_get_drvdata(pdev);;
 690
 691         return i2c_add_driver(&cs4270_i2c_driver);
 692 }
 693
 694 static int cs4270_remove(struct platform_device *pdev)
 695 {
 696         i2c_del_driver(&cs4270_i2c_driver);
 697
 698         return 0;
 699 }
 700
 701 /*
 702  * ASoC codec device structure
 703  *
 704  * Assign this variable to the codec_dev field of the machine driver's
 705  * snd_soc_device structure.
 706  */
 707 struct snd_soc_codec_device soc_codec_device_cs4270 = {
 708         .probe =        cs4270_probe,
 709         .remove =       cs4270_remove
 710 };
 711 EXPORT_SYMBOL_GPL(soc_codec_device_cs4270);
 712
 713 static int __init cs4270_init(void)
 714 {
 715         printk(KERN_INFO "Cirrus Logic CS4270 ALSA SoC Codec Driver\n");
 716
 717         return snd_soc_register_dai(&cs4270_dai);
 718 }
 719 module_init(cs4270_init);
 720
 721 static void __exit cs4270_exit(void)
 722 {
 723         snd_soc_unregister_dai(&cs4270_dai);
 724 }
 725 module_exit(cs4270_exit);
 726
 727 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
 728 MODULE_DESCRIPTION("Cirrus Logic CS4270 ALSA SoC Codec Driver");
 729 MODULE_LICENSE("GPL");