sound/soc/codecs/cs4270.c

   1 /*
   2  * CS4270 ALSA SoC (ASoC) codec driver
   3  *
   4  * Author: Timur Tabi <timur@freescale.com>
   5  *
   6  * Copyright 2007-2009 Freescale Semiconductor, Inc.  This file is licensed
   7  * under the terms of the GNU General Public License version 2.  This
   8  * program is licensed "as is" without any warranty of any kind, whether
   9  * express or implied.
  10  *
  11  * This is an ASoC device driver for the Cirrus Logic CS4270 codec.
  12  *
  13  * Current features/limitations:
  14  *
  15  * - Software mode is supported.  Stand-alone mode is not supported.
  16  * - Only I2C is supported, not SPI
  17  * - Support for master and slave mode
  18  * - The machine driver's 'startup' function must call
  19  *   cs4270_set_dai_sysclk() with the value of MCLK.
  20  * - Only I2S and left-justified modes are supported
  21  * - Power management is not supported
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/platform_device.h>
  26 #include <sound/core.h>
  27 #include <sound/soc.h>
  28 #include <sound/initval.h>
  29 #include <linux/i2c.h>
  30
  31 #include "cs4270.h"
  32
  33 /*
  34  * The codec isn't really big-endian or little-endian, since the I2S
  35  * interface requires data to be sent serially with the MSbit first.
  36  * However, to support BE and LE I2S devices, we specify both here.  That
  37  * way, ALSA will always match the bit patterns.
  38  */
  39 #define CS4270_FORMATS (SNDRV_PCM_FMTBIT_S8      | \
  40                         SNDRV_PCM_FMTBIT_S16_LE  | SNDRV_PCM_FMTBIT_S16_BE  | \
  41                         SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S18_3BE | \
  42                         SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S20_3BE | \
  43                         SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE | \
  44                         SNDRV_PCM_FMTBIT_S24_LE  | SNDRV_PCM_FMTBIT_S24_BE)
  45
  46 /* CS4270 registers addresses */
  47 #define CS4270_CHIPID   0x01    /* Chip ID */
  48 #define CS4270_PWRCTL   0x02    /* Power Control */
  49 #define CS4270_MODE     0x03    /* Mode Control */
  50 #define CS4270_FORMAT   0x04    /* Serial Format, ADC/DAC Control */
  51 #define CS4270_TRANS    0x05    /* Transition Control */
  52 #define CS4270_MUTE     0x06    /* Mute Control */
  53 #define CS4270_VOLA     0x07    /* DAC Channel A Volume Control */
  54 #define CS4270_VOLB     0x08    /* DAC Channel B Volume Control */
  55
  56 #define CS4270_FIRSTREG 0x01
  57 #define CS4270_LASTREG  0x08
  58 #define CS4270_NUMREGS  (CS4270_LASTREG - CS4270_FIRSTREG + 1)
  59 #define CS4270_I2C_INCR 0x80
  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         unsigned int slave_mode;
 113         unsigned int manual_mute;
 114 };
 115
 116 /**
 117  * struct cs4270_mode_ratios - clock ratio tables
 118  * @ratio: the ratio of MCLK to the sample rate
 119  * @speed_mode: the Speed Mode bits to set in the Mode Control register for
 120  *              this ratio
 121  * @mclk: the Ratio Select bits to set in the Mode Control register for this
 122  *        ratio
 123  *
 124  * The data for this chart is taken from Table 5 of the CS4270 reference
 125  * manual.
 126  *
 127  * This table is used to determine how to program the Mode Control register.
 128  * It is also used by cs4270_set_dai_sysclk() to tell ALSA which sampling
 129  * rates the CS4270 currently supports.
 130  *
 131  * @speed_mode is the corresponding bit pattern to be written to the
 132  * MODE bits of the Mode Control Register
 133  *
 134  * @mclk is the corresponding bit pattern to be wirten to the MCLK bits of
 135  * the Mode Control Register.
 136  *
 137  * In situations where a single ratio is represented by multiple speed
 138  * modes, we favor the slowest speed.  E.g, for a ratio of 128, we pick
 139  * double-speed instead of quad-speed.  However, the CS4270 errata states
 140  * that divide-By-1.5 can cause failures, so we avoid that mode where
 141  * possible.
 142  *
 143  * Errata: There is an errata for the CS4270 where divide-by-1.5 does not
 144  * work if Vd is 3.3V.  If this effects you, select the
 145  * CONFIG_SND_SOC_CS4270_VD33_ERRATA Kconfig option, and the driver will
 146  * never select any sample rates that require divide-by-1.5.
 147  */
 148 struct cs4270_mode_ratios {
 149         unsigned int ratio;
 150         u8 speed_mode;
 151         u8 mclk;
 152 };
 153
 154 static struct cs4270_mode_ratios cs4270_mode_ratios[] = {
 155         {64, CS4270_MODE_4X, CS4270_MODE_DIV1},
 156 #ifndef CONFIG_SND_SOC_CS4270_VD33_ERRATA
 157         {96, CS4270_MODE_4X, CS4270_MODE_DIV15},
 158 #endif
 159         {128, CS4270_MODE_2X, CS4270_MODE_DIV1},
 160         {192, CS4270_MODE_4X, CS4270_MODE_DIV3},
 161         {256, CS4270_MODE_1X, CS4270_MODE_DIV1},
 162         {384, CS4270_MODE_2X, CS4270_MODE_DIV3},
 163         {512, CS4270_MODE_1X, CS4270_MODE_DIV2},
 164         {768, CS4270_MODE_1X, CS4270_MODE_DIV3},
 165         {1024, CS4270_MODE_1X, CS4270_MODE_DIV4}
 166 };
 167
 168 /* The number of MCLK/LRCK ratios supported by the CS4270 */
 169 #define NUM_MCLK_RATIOS         ARRAY_SIZE(cs4270_mode_ratios)
 170
 171 /**
 172  * cs4270_set_dai_sysclk - determine the CS4270 samples rates.
 173  * @codec_dai: the codec DAI
 174  * @clk_id: the clock ID (ignored)
 175  * @freq: the MCLK input frequency
 176  * @dir: the clock direction (ignored)
 177  *
 178  * This function is used to tell the codec driver what the input MCLK
 179  * frequency is.
 180  *
 181  * The value of MCLK is used to determine which sample rates are supported
 182  * by the CS4270.  The ratio of MCLK / Fs must be equal to one of nine
 183  * supported values - 64, 96, 128, 192, 256, 384, 512, 768, and 1024.
 184  *
 185  * This function calculates the nine ratios and determines which ones match
 186  * a standard sample rate.  If there's a match, then it is added to the list
 187  * of supported sample rates.
 188  *
 189  * This function must be called by the machine driver's 'startup' function,
 190  * otherwise the list of supported sample rates will not be available in
 191  * time for ALSA.
 192  */
 193 static int cs4270_set_dai_sysclk(struct snd_soc_dai *codec_dai,
 194                                  int clk_id, unsigned int freq, int dir)
 195 {
 196         struct snd_soc_codec *codec = codec_dai->codec;
 197         struct cs4270_private *cs4270 = codec->private_data;
 198         unsigned int rates = 0;
 199         unsigned int rate_min = -1;
 200         unsigned int rate_max = 0;
 201         unsigned int i;
 202
 203         cs4270->mclk = freq;
 204
 205         for (i = 0; i < NUM_MCLK_RATIOS; i++) {
 206                 unsigned int rate = freq / cs4270_mode_ratios[i].ratio;
 207                 rates |= snd_pcm_rate_to_rate_bit(rate);
 208                 if (rate < rate_min)
 209                         rate_min = rate;
 210                 if (rate > rate_max)
 211                         rate_max = rate;
 212         }
 213         /* FIXME: soc should support a rate list */
 214         rates &= ~SNDRV_PCM_RATE_KNOT;
 215
 216         if (!rates) {
 217                 dev_err(codec->dev, "could not find a valid sample rate\n");
 218                 return -EINVAL;
 219         }
 220
 221         codec_dai->playback.rates = rates;
 222         codec_dai->playback.rate_min = rate_min;
 223         codec_dai->playback.rate_max = rate_max;
 224
 225         codec_dai->capture.rates = rates;
 226         codec_dai->capture.rate_min = rate_min;
 227         codec_dai->capture.rate_max = rate_max;
 228
 229         return 0;
 230 }
 231
 232 /**
 233  * cs4270_set_dai_fmt - configure the codec for the selected audio format
 234  * @codec_dai: the codec DAI
 235  * @format: a SND_SOC_DAIFMT_x value indicating the data format
 236  *
 237  * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the
 238  * codec accordingly.
 239  *
 240  * Currently, this function only supports SND_SOC_DAIFMT_I2S and
 241  * SND_SOC_DAIFMT_LEFT_J.  The CS4270 codec also supports right-justified
 242  * data for playback only, but ASoC currently does not support different
 243  * formats for playback vs. record.
 244  */
 245 static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai,
 246                               unsigned int format)
 247 {
 248         struct snd_soc_codec *codec = codec_dai->codec;
 249         struct cs4270_private *cs4270 = codec->private_data;
 250         int ret = 0;
 251
 252         /* set DAI format */
 253         switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
 254         case SND_SOC_DAIFMT_I2S:
 255         case SND_SOC_DAIFMT_LEFT_J:
 256                 cs4270->mode = format & SND_SOC_DAIFMT_FORMAT_MASK;
 257                 break;
 258         default:
 259                 dev_err(codec->dev, "invalid dai format\n");
 260                 ret = -EINVAL;
 261         }
 262
 263         /* set master/slave audio interface */
 264         switch (format & SND_SOC_DAIFMT_MASTER_MASK) {
 265         case SND_SOC_DAIFMT_CBS_CFS:
 266                 cs4270->slave_mode = 1;
 267                 break;
 268         case SND_SOC_DAIFMT_CBM_CFM:
 269                 cs4270->slave_mode = 0;
 270                 break;
 271         default:
 272                 /* all other modes are unsupported by the hardware */
 273                 ret = -EINVAL;
 274         }
 275
 276         return ret;
 277 }
 278
 279 /**
 280  * cs4270_fill_cache - pre-fill the CS4270 register cache.
 281  * @codec: the codec for this CS4270
 282  *
 283  * This function fills in the CS4270 register cache by reading the register
 284  * values from the hardware.
 285  *
 286  * This CS4270 registers are cached to avoid excessive I2C I/O operations.
 287  * After the initial read to pre-fill the cache, the CS4270 never updates
 288  * the register values, so we won't have a cache coherency problem.
 289  *
 290  * We use the auto-increment feature of the CS4270 to read all registers in
 291  * one shot.
 292  */
 293 static int cs4270_fill_cache(struct snd_soc_codec *codec)
 294 {
 295         u8 *cache = codec->reg_cache;
 296         struct i2c_client *i2c_client = codec->control_data;
 297         s32 length;
 298
 299         length = i2c_smbus_read_i2c_block_data(i2c_client,
 300                 CS4270_FIRSTREG | CS4270_I2C_INCR, CS4270_NUMREGS, cache);
 301
 302         if (length != CS4270_NUMREGS) {
 303                 dev_err(codec->dev, "i2c read failure, addr=0x%x\n",
 304                        i2c_client->addr);
 305                 return -EIO;
 306         }
 307
 308         return 0;
 309 }
 310
 311 /**
 312  * cs4270_read_reg_cache - read from the CS4270 register cache.
 313  * @codec: the codec for this CS4270
 314  * @reg: the register to read
 315  *
 316  * This function returns the value for a given register.  It reads only from
 317  * the register cache, not the hardware itself.
 318  *
 319  * This CS4270 registers are cached to avoid excessive I2C I/O operations.
 320  * After the initial read to pre-fill the cache, the CS4270 never updates
 321  * the register values, so we won't have a cache coherency problem.
 322  */
 323 static unsigned int cs4270_read_reg_cache(struct snd_soc_codec *codec,
 324         unsigned int reg)
 325 {
 326         u8 *cache = codec->reg_cache;
 327
 328         if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
 329                 return -EIO;
 330
 331         return cache[reg - CS4270_FIRSTREG];
 332 }
 333
 334 /**
 335  * cs4270_i2c_write - write to a CS4270 register via the I2C bus.
 336  * @codec: the codec for this CS4270
 337  * @reg: the register to write
 338  * @value: the value to write to the register
 339  *
 340  * This function writes the given value to the given CS4270 register, and
 341  * also updates the register cache.
 342  *
 343  * Note that we don't use the hw_write function pointer of snd_soc_codec.
 344  * That's because it's too clunky: the hw_write_t prototype does not match
 345  * i2c_smbus_write_byte_data(), and it's just another layer of overhead.
 346  */
 347 static int cs4270_i2c_write(struct snd_soc_codec *codec, unsigned int reg,
 348                             unsigned int value)
 349 {
 350         u8 *cache = codec->reg_cache;
 351
 352         if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
 353                 return -EIO;
 354
 355         /* Only perform an I2C operation if the new value is different */
 356         if (cache[reg - CS4270_FIRSTREG] != value) {
 357                 struct i2c_client *client = codec->control_data;
 358                 if (i2c_smbus_write_byte_data(client, reg, value)) {
 359                         dev_err(codec->dev, "i2c write failed\n");
 360                         return -EIO;
 361                 }
 362
 363                 /* We've written to the hardware, so update the cache */
 364                 cache[reg - CS4270_FIRSTREG] = value;
 365         }
 366
 367         return 0;
 368 }
 369
 370 /**
 371  * cs4270_hw_params - program the CS4270 with the given hardware parameters.
 372  * @substream: the audio stream
 373  * @params: the hardware parameters to set
 374  * @dai: the SOC DAI (ignored)
 375  *
 376  * This function programs the hardware with the values provided.
 377  * Specifically, the sample rate and the data format.
 378  *
 379  * The .ops functions are used to provide board-specific data, like input
 380  * frequencies, to this driver.  This function takes that information,
 381  * combines it with the hardware parameters provided, and programs the
 382  * hardware accordingly.
 383  */
 384 static int cs4270_hw_params(struct snd_pcm_substream *substream,
 385                             struct snd_pcm_hw_params *params,
 386                             struct snd_soc_dai *dai)
 387 {
 388         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 389         struct snd_soc_device *socdev = rtd->socdev;
 390         struct snd_soc_codec *codec = socdev->card->codec;
 391         struct cs4270_private *cs4270 = codec->private_data;
 392         int ret;
 393         unsigned int i;
 394         unsigned int rate;
 395         unsigned int ratio;
 396         int reg;
 397
 398         /* Figure out which MCLK/LRCK ratio to use */
 399
 400         rate = params_rate(params);     /* Sampling rate, in Hz */
 401         ratio = cs4270->mclk / rate;    /* MCLK/LRCK ratio */
 402
 403         for (i = 0; i < NUM_MCLK_RATIOS; i++) {
 404                 if (cs4270_mode_ratios[i].ratio == ratio)
 405                         break;
 406         }
 407
 408         if (i == NUM_MCLK_RATIOS) {
 409                 /* We did not find a matching ratio */
 410                 dev_err(codec->dev, "could not find matching ratio\n");
 411                 return -EINVAL;
 412         }
 413
 414         /* Set the sample rate */
 415
 416         reg = snd_soc_read(codec, CS4270_MODE);
 417         reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK);
 418         reg |= cs4270_mode_ratios[i].mclk;
 419
 420         if (cs4270->slave_mode)
 421                 reg |= CS4270_MODE_SLAVE;
 422         else
 423                 reg |= cs4270_mode_ratios[i].speed_mode;
 424
 425         ret = snd_soc_write(codec, CS4270_MODE, reg);
 426         if (ret < 0) {
 427                 dev_err(codec->dev, "i2c write failed\n");
 428                 return ret;
 429         }
 430
 431         /* Set the DAI format */
 432
 433         reg = snd_soc_read(codec, CS4270_FORMAT);
 434         reg &= ~(CS4270_FORMAT_DAC_MASK | CS4270_FORMAT_ADC_MASK);
 435
 436         switch (cs4270->mode) {
 437         case SND_SOC_DAIFMT_I2S:
 438                 reg |= CS4270_FORMAT_DAC_I2S | CS4270_FORMAT_ADC_I2S;
 439                 break;
 440         case SND_SOC_DAIFMT_LEFT_J:
 441                 reg |= CS4270_FORMAT_DAC_LJ | CS4270_FORMAT_ADC_LJ;
 442                 break;
 443         default:
 444                 dev_err(codec->dev, "unknown dai format\n");
 445                 return -EINVAL;
 446         }
 447
 448         ret = snd_soc_write(codec, CS4270_FORMAT, reg);
 449         if (ret < 0) {
 450                 dev_err(codec->dev, "i2c write failed\n");
 451                 return ret;
 452         }
 453
 454         return ret;
 455 }
 456
 457 /**
 458  * cs4270_dai_mute - enable/disable the CS4270 external mute
 459  * @dai: the SOC DAI
 460  * @mute: 0 = disable mute, 1 = enable mute
 461  *
 462  * This function toggles the mute bits in the MUTE register.  The CS4270's
 463  * mute capability is intended for external muting circuitry, so if the
 464  * board does not have the MUTEA or MUTEB pins connected to such circuitry,
 465  * then this function will do nothing.
 466  */
 467 static int cs4270_dai_mute(struct snd_soc_dai *dai, int mute)
 468 {
 469         struct snd_soc_codec *codec = dai->codec;
 470         struct cs4270_private *cs4270 = codec->private_data;
 471         int reg6;
 472
 473         reg6 = snd_soc_read(codec, CS4270_MUTE);
 474
 475         if (mute)
 476                 reg6 |= CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B;
 477         else {
 478                 reg6 &= ~(CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B);
 479                 reg6 |= cs4270->manual_mute;
 480         }
 481
 482         return snd_soc_write(codec, CS4270_MUTE, reg6);
 483 }
 484
 485 /**
 486  * cs4270_soc_put_mute - put callback for the 'Master Playback switch'
 487  *                       alsa control.
 488  * @kcontrol: mixer control
 489  * @ucontrol: control element information
 490  *
 491  * This function basically passes the arguments on to the generic
 492  * snd_soc_put_volsw() function and saves the mute information in
 493  * our private data structure. This is because we want to prevent
 494  * cs4270_dai_mute() neglecting the user's decision to manually
 495  * mute the codec's output.
 496  *
 497  * Returns 0 for success.
 498  */
 499 static int cs4270_soc_put_mute(struct snd_kcontrol *kcontrol,
 500                                 struct snd_ctl_elem_value *ucontrol)
 501 {
 502         struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
 503         struct cs4270_private *cs4270 = codec->private_data;
 504         int left = !ucontrol->value.integer.value[0];
 505         int right = !ucontrol->value.integer.value[1];
 506
 507         cs4270->manual_mute = (left ? CS4270_MUTE_DAC_A : 0) |
 508                               (right ? CS4270_MUTE_DAC_B : 0);
 509
 510         return snd_soc_put_volsw(kcontrol, ucontrol);
 511 }
 512
 513 /* A list of non-DAPM controls that the CS4270 supports */
 514 static const struct snd_kcontrol_new cs4270_snd_controls[] = {
 515         SOC_DOUBLE_R("Master Playback Volume",
 516                 CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 1),
 517         SOC_SINGLE("Digital Sidetone Switch", CS4270_FORMAT, 5, 1, 0),
 518         SOC_SINGLE("Soft Ramp Switch", CS4270_TRANS, 6, 1, 0),
 519         SOC_SINGLE("Zero Cross Switch", CS4270_TRANS, 5, 1, 0),
 520         SOC_SINGLE("Popguard Switch", CS4270_MODE, 0, 1, 1),
 521         SOC_SINGLE("Auto-Mute Switch", CS4270_MUTE, 5, 1, 0),
 522         SOC_DOUBLE("Master Capture Switch", CS4270_MUTE, 3, 4, 1, 1),
 523         SOC_DOUBLE_EXT("Master Playback Switch", CS4270_MUTE, 0, 1, 1, 1,
 524                 snd_soc_get_volsw, cs4270_soc_put_mute),
 525 };
 526
 527 /*
 528  * cs4270_codec - global variable to store codec for the ASoC probe function
 529  *
 530  * If struct i2c_driver had a private_data field, we wouldn't need to use
 531  * cs4270_codec.  This is the only way to pass the codec structure from
 532  * cs4270_i2c_probe() to cs4270_probe().  Unfortunately, there is no good
 533  * way to synchronize these two functions.  cs4270_i2c_probe() can be called
 534  * multiple times before cs4270_probe() is called even once.  So for now, we
 535  * also only allow cs4270_i2c_probe() to be run once.  That means that we do
 536  * not support more than one cs4270 device in the system, at least for now.
 537  */
 538 static struct snd_soc_codec *cs4270_codec;
 539
 540 static struct snd_soc_dai_ops cs4270_dai_ops = {
 541         .hw_params      = cs4270_hw_params,
 542         .set_sysclk     = cs4270_set_dai_sysclk,
 543         .set_fmt        = cs4270_set_dai_fmt,
 544         .digital_mute   = cs4270_dai_mute,
 545 };
 546
 547 struct snd_soc_dai cs4270_dai = {
 548         .name = "cs4270",
 549         .playback = {
 550                 .stream_name = "Playback",
 551                 .channels_min = 1,
 552                 .channels_max = 2,
 553                 .rates = 0,
 554                 .formats = CS4270_FORMATS,
 555         },
 556         .capture = {
 557                 .stream_name = "Capture",
 558                 .channels_min = 1,
 559                 .channels_max = 2,
 560                 .rates = 0,
 561                 .formats = CS4270_FORMATS,
 562         },
 563         .ops = &cs4270_dai_ops,
 564 };
 565 EXPORT_SYMBOL_GPL(cs4270_dai);
 566
 567 /**
 568  * cs4270_probe - ASoC probe function
 569  * @pdev: platform device
 570  *
 571  * This function is called when ASoC has all the pieces it needs to
 572  * instantiate a sound driver.
 573  */
 574 static int cs4270_probe(struct platform_device *pdev)
 575 {
 576         struct snd_soc_device *socdev = platform_get_drvdata(pdev);
 577         struct snd_soc_codec *codec = cs4270_codec;
 578         int ret;
 579
 580         /* Connect the codec to the socdev.  snd_soc_new_pcms() needs this. */
 581         socdev->card->codec = codec;
 582
 583         /* Register PCMs */
 584         ret = snd_soc_new_pcms(socdev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1);
 585         if (ret < 0) {
 586                 dev_err(codec->dev, "failed to create pcms\n");
 587                 return ret;
 588         }
 589
 590         /* Add the non-DAPM controls */
 591         ret = snd_soc_add_controls(codec, cs4270_snd_controls,
 592                                 ARRAY_SIZE(cs4270_snd_controls));
 593         if (ret < 0) {
 594                 dev_err(codec->dev, "failed to add controls\n");
 595                 goto error_free_pcms;
 596         }
 597
 598         /* And finally, register the socdev */
 599         ret = snd_soc_init_card(socdev);
 600         if (ret < 0) {
 601                 dev_err(codec->dev, "failed to register card\n");
 602                 goto error_free_pcms;
 603         }
 604
 605         return 0;
 606
 607 error_free_pcms:
 608         snd_soc_free_pcms(socdev);
 609
 610         return ret;
 611 }
 612
 613 /**
 614  * cs4270_remove - ASoC remove function
 615  * @pdev: platform device
 616  *
 617  * This function is the counterpart to cs4270_probe().
 618  */
 619 static int cs4270_remove(struct platform_device *pdev)
 620 {
 621         struct snd_soc_device *socdev = platform_get_drvdata(pdev);
 622
 623         snd_soc_free_pcms(socdev);
 624
 625         return 0;
 626 };
 627
 628 /**
 629  * cs4270_i2c_probe - initialize the I2C interface of the CS4270
 630  * @i2c_client: the I2C client object
 631  * @id: the I2C device ID (ignored)
 632  *
 633  * This function is called whenever the I2C subsystem finds a device that
 634  * matches the device ID given via a prior call to i2c_add_driver().
 635  */
 636 static int cs4270_i2c_probe(struct i2c_client *i2c_client,
 637         const struct i2c_device_id *id)
 638 {
 639         struct snd_soc_codec *codec;
 640         struct cs4270_private *cs4270;
 641         unsigned int reg;
 642         int ret;
 643
 644         /* For now, we only support one cs4270 device in the system.  See the
 645          * comment for cs4270_codec.
 646          */
 647         if (cs4270_codec) {
 648                 dev_err(&i2c_client->dev, "ignoring CS4270 at addr %X\n",
 649                        i2c_client->addr);
 650                 dev_err(&i2c_client->dev, "only one per board allowed\n");
 651                 /* Should we return something other than ENODEV here? */
 652                 return -ENODEV;
 653         }
 654
 655         /* Verify that we have a CS4270 */
 656
 657         ret = i2c_smbus_read_byte_data(i2c_client, CS4270_CHIPID);
 658         if (ret < 0) {
 659                 dev_err(&i2c_client->dev, "failed to read i2c at addr %X\n",
 660                        i2c_client->addr);
 661                 return ret;
 662         }
 663         /* The top four bits of the chip ID should be 1100. */
 664         if ((ret & 0xF0) != 0xC0) {
 665                 dev_err(&i2c_client->dev, "device at addr %X is not a CS4270\n",
 666                        i2c_client->addr);
 667                 return -ENODEV;
 668         }
 669
 670         dev_info(&i2c_client->dev, "found device at i2c address %X\n",
 671                 i2c_client->addr);
 672         dev_info(&i2c_client->dev, "hardware revision %X\n", ret & 0xF);
 673
 674         /* Allocate enough space for the snd_soc_codec structure
 675            and our private data together. */
 676         cs4270 = kzalloc(sizeof(struct cs4270_private), GFP_KERNEL);
 677         if (!cs4270) {
 678                 dev_err(&i2c_client->dev, "could not allocate codec\n");
 679                 return -ENOMEM;
 680         }
 681         codec = &cs4270->codec;
 682
 683         mutex_init(&codec->mutex);
 684         INIT_LIST_HEAD(&codec->dapm_widgets);
 685         INIT_LIST_HEAD(&codec->dapm_paths);
 686
 687         codec->dev = &i2c_client->dev;
 688         codec->name = "CS4270";
 689         codec->owner = THIS_MODULE;
 690         codec->dai = &cs4270_dai;
 691         codec->num_dai = 1;
 692         codec->private_data = cs4270;
 693         codec->control_data = i2c_client;
 694         codec->read = cs4270_read_reg_cache;
 695         codec->write = cs4270_i2c_write;
 696         codec->reg_cache = cs4270->reg_cache;
 697         codec->reg_cache_size = CS4270_NUMREGS;
 698
 699         /* The I2C interface is set up, so pre-fill our register cache */
 700
 701         ret = cs4270_fill_cache(codec);
 702         if (ret < 0) {
 703                 dev_err(&i2c_client->dev, "failed to fill register cache\n");
 704                 goto error_free_codec;
 705         }
 706
 707         /* Disable auto-mute.  This feature appears to be buggy.  In some
 708          * situations, auto-mute will not deactivate when it should, so we want
 709          * this feature disabled by default.  An application (e.g. alsactl) can
 710          * re-enabled it by using the controls.
 711          */
 712
 713         reg = cs4270_read_reg_cache(codec, CS4270_MUTE);
 714         reg &= ~CS4270_MUTE_AUTO;
 715         ret = cs4270_i2c_write(codec, CS4270_MUTE, reg);
 716         if (ret < 0) {
 717                 dev_err(&i2c_client->dev, "i2c write failed\n");
 718                 return ret;
 719         }
 720
 721         /* Disable automatic volume control.  The hardware enables, and it
 722          * causes volume change commands to be delayed, sometimes until after
 723          * playback has started.  An application (e.g. alsactl) can
 724          * re-enabled it by using the controls.
 725          */
 726
 727         reg = cs4270_read_reg_cache(codec, CS4270_TRANS);
 728         reg &= ~(CS4270_TRANS_SOFT | CS4270_TRANS_ZERO);
 729         ret = cs4270_i2c_write(codec, CS4270_TRANS, reg);
 730         if (ret < 0) {
 731                 dev_err(&i2c_client->dev, "i2c write failed\n");
 732                 return ret;
 733         }
 734
 735         /* Initialize the DAI. Normally, we'd prefer to have a kmalloc'd DAI
 736          * structure for each CS4270 device, but the machine driver needs to
 737          * have a pointer to the DAI structure, so for now it must be a global
 738          * variable.
 739          */
 740         cs4270_dai.dev = &i2c_client->dev;
 741
 742         /* Register the DAI.  If all the other ASoC driver have already
 743          * registered, then this will call our probe function, so
 744          * cs4270_codec needs to be ready.
 745          */
 746         cs4270_codec = codec;
 747         ret = snd_soc_register_dai(&cs4270_dai);
 748         if (ret < 0) {
 749                 dev_err(&i2c_client->dev, "failed to register DAIe\n");
 750                 goto error_free_codec;
 751         }
 752
 753         i2c_set_clientdata(i2c_client, cs4270);
 754
 755         return 0;
 756
 757 error_free_codec:
 758         kfree(cs4270);
 759         cs4270_codec = NULL;
 760         cs4270_dai.dev = NULL;
 761
 762         return ret;
 763 }
 764
 765 /**
 766  * cs4270_i2c_remove - remove an I2C device
 767  * @i2c_client: the I2C client object
 768  *
 769  * This function is the counterpart to cs4270_i2c_probe().
 770  */
 771 static int cs4270_i2c_remove(struct i2c_client *i2c_client)
 772 {
 773         struct cs4270_private *cs4270 = i2c_get_clientdata(i2c_client);
 774
 775         kfree(cs4270);
 776         cs4270_codec = NULL;
 777         cs4270_dai.dev = NULL;
 778
 779         return 0;
 780 }
 781
 782 /*
 783  * cs4270_id - I2C device IDs supported by this driver
 784  */
 785 static struct i2c_device_id cs4270_id[] = {
 786         {"cs4270", 0},
 787         {}
 788 };
 789 MODULE_DEVICE_TABLE(i2c, cs4270_id);
 790
 791 /*
 792  * cs4270_i2c_driver - I2C device identification
 793  *
 794  * This structure tells the I2C subsystem how to identify and support a
 795  * given I2C device type.
 796  */
 797 static struct i2c_driver cs4270_i2c_driver = {
 798         .driver = {
 799                 .name = "cs4270",
 800                 .owner = THIS_MODULE,
 801         },
 802         .id_table = cs4270_id,
 803         .probe = cs4270_i2c_probe,
 804         .remove = cs4270_i2c_remove,
 805 };
 806
 807 /*
 808  * ASoC codec device structure
 809  *
 810  * Assign this variable to the codec_dev field of the machine driver's
 811  * snd_soc_device structure.
 812  */
 813 struct snd_soc_codec_device soc_codec_device_cs4270 = {
 814         .probe =        cs4270_probe,
 815         .remove =       cs4270_remove
 816 };
 817 EXPORT_SYMBOL_GPL(soc_codec_device_cs4270);
 818
 819 static int __init cs4270_init(void)
 820 {
 821         pr_info("Cirrus Logic CS4270 ALSA SoC Codec Driver\n");
 822
 823         return i2c_add_driver(&cs4270_i2c_driver);
 824 }
 825 module_init(cs4270_init);
 826
 827 static void __exit cs4270_exit(void)
 828 {
 829         i2c_del_driver(&cs4270_i2c_driver);
 830 }
 831 module_exit(cs4270_exit);
 832
 833 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
 834 MODULE_DESCRIPTION("Cirrus Logic CS4270 ALSA SoC Codec Driver");
 835 MODULE_LICENSE("GPL");