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 automatically
  16  *    selected if I2C is disabled or if a CS4270 is not found on the I2C
  17  *    bus.  However, stand-alone mode is only partially implemented because
  18  *    there is no mechanism yet for this driver and the machine driver to
  19  *    communicate the values of the M0, M1, MCLK1, and MCLK2 pins.
  20  * 2) Only I2C is supported, not SPI
  21  * 3) Only Master mode is supported, not Slave.
  22  * 4) The machine driver's 'startup' function must call
  23  *    cs4270_set_dai_sysclk() with the value of MCLK.
  24  * 5) Only I2S and left-justified modes are supported
  25  * 6) Power management is not supported
  26  * 7) The only supported control is volume and hardware mute (if enabled)
  27  */
  28
  29 #include <linux/module.h>
  30 #include <linux/platform_device.h>
  31 #include <sound/core.h>
  32 #include <sound/soc.h>
  33 #include <sound/initval.h>
  34 #include <linux/i2c.h>
  35
  36 #include "cs4270.h"
  37
  38 /* If I2C is defined, then we support software mode.  However, if we're
  39    not compiled as module but I2C is, then we can't use I2C calls. */
  40 #if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
  41 #define USE_I2C
  42 #endif
  43
  44 /* Private data for the CS4270 */
  45 struct cs4270_private {
  46         unsigned int mclk; /* Input frequency of the MCLK pin */
  47         unsigned int mode; /* The mode (I2S or left-justified) */
  48 };
  49
  50 /*
  51  * The codec isn't really big-endian or little-endian, since the I2S
  52  * interface requires data to be sent serially with the MSbit first.
  53  * However, to support BE and LE I2S devices, we specify both here.  That
  54  * way, ALSA will always match the bit patterns.
  55  */
  56 #define CS4270_FORMATS (SNDRV_PCM_FMTBIT_S8      | \
  57                         SNDRV_PCM_FMTBIT_S16_LE  | SNDRV_PCM_FMTBIT_S16_BE  | \
  58                         SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S18_3BE | \
  59                         SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S20_3BE | \
  60                         SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE | \
  61                         SNDRV_PCM_FMTBIT_S24_LE  | SNDRV_PCM_FMTBIT_S24_BE)
  62
  63 #ifdef USE_I2C
  64
  65 /* CS4270 registers addresses */
  66 #define CS4270_CHIPID   0x01    /* Chip ID */
  67 #define CS4270_PWRCTL   0x02    /* Power Control */
  68 #define CS4270_MODE     0x03    /* Mode Control */
  69 #define CS4270_FORMAT   0x04    /* Serial Format, ADC/DAC Control */
  70 #define CS4270_TRANS    0x05    /* Transition Control */
  71 #define CS4270_MUTE     0x06    /* Mute Control */
  72 #define CS4270_VOLA     0x07    /* DAC Channel A Volume Control */
  73 #define CS4270_VOLB     0x08    /* DAC Channel B Volume Control */
  74
  75 #define CS4270_FIRSTREG 0x01
  76 #define CS4270_LASTREG  0x08
  77 #define CS4270_NUMREGS  (CS4270_LASTREG - CS4270_FIRSTREG + 1)
  78
  79 /* Bit masks for the CS4270 registers */
  80 #define CS4270_CHIPID_ID        0xF0
  81 #define CS4270_CHIPID_REV       0x0F
  82 #define CS4270_PWRCTL_FREEZE    0x80
  83 #define CS4270_PWRCTL_PDN_ADC   0x20
  84 #define CS4270_PWRCTL_PDN_DAC   0x02
  85 #define CS4270_PWRCTL_PDN       0x01
  86 #define CS4270_MODE_SPEED_MASK  0x30
  87 #define CS4270_MODE_1X          0x00
  88 #define CS4270_MODE_2X          0x10
  89 #define CS4270_MODE_4X          0x20
  90 #define CS4270_MODE_SLAVE       0x30
  91 #define CS4270_MODE_DIV_MASK    0x0E
  92 #define CS4270_MODE_DIV1        0x00
  93 #define CS4270_MODE_DIV15       0x02
  94 #define CS4270_MODE_DIV2        0x04
  95 #define CS4270_MODE_DIV3        0x06
  96 #define CS4270_MODE_DIV4        0x08
  97 #define CS4270_MODE_POPGUARD    0x01
  98 #define CS4270_FORMAT_FREEZE_A  0x80
  99 #define CS4270_FORMAT_FREEZE_B  0x40
 100 #define CS4270_FORMAT_LOOPBACK  0x20
 101 #define CS4270_FORMAT_DAC_MASK  0x18
 102 #define CS4270_FORMAT_DAC_LJ    0x00
 103 #define CS4270_FORMAT_DAC_I2S   0x08
 104 #define CS4270_FORMAT_DAC_RJ16  0x18
 105 #define CS4270_FORMAT_DAC_RJ24  0x10
 106 #define CS4270_FORMAT_ADC_MASK  0x01
 107 #define CS4270_FORMAT_ADC_LJ    0x00
 108 #define CS4270_FORMAT_ADC_I2S   0x01
 109 #define CS4270_TRANS_ONE_VOL    0x80
 110 #define CS4270_TRANS_SOFT       0x40
 111 #define CS4270_TRANS_ZERO       0x20
 112 #define CS4270_TRANS_INV_ADC_A  0x08
 113 #define CS4270_TRANS_INV_ADC_B  0x10
 114 #define CS4270_TRANS_INV_DAC_A  0x02
 115 #define CS4270_TRANS_INV_DAC_B  0x04
 116 #define CS4270_TRANS_DEEMPH     0x01
 117 #define CS4270_MUTE_AUTO        0x20
 118 #define CS4270_MUTE_ADC_A       0x08
 119 #define CS4270_MUTE_ADC_B       0x10
 120 #define CS4270_MUTE_POLARITY    0x04
 121 #define CS4270_MUTE_DAC_A       0x01
 122 #define CS4270_MUTE_DAC_B       0x02
 123
 124 /*
 125  * Clock Ratio Selection for Master Mode with I2C enabled
 126  *
 127  * The data for this chart is taken from Table 5 of the CS4270 reference
 128  * manual.
 129  *
 130  * This table is used to determine how to program the Mode Control register.
 131  * It is also used by cs4270_set_dai_sysclk() to tell ALSA which sampling
 132  * rates the CS4270 currently supports.
 133  *
 134  * Each element in this array corresponds to the ratios in mclk_ratios[].
 135  * These two arrays need to be in sync.
 136  *
 137  * 'speed_mode' is the corresponding bit pattern to be written to the
 138  * MODE bits of the Mode Control Register
 139  *
 140  * 'mclk' is the corresponding bit pattern to be wirten to the MCLK bits of
 141  * the Mode Control Register.
 142  *
 143  * In situations where a single ratio is represented by multiple speed
 144  * modes, we favor the slowest speed.  E.g, for a ratio of 128, we pick
 145  * double-speed instead of quad-speed.  However, the CS4270 errata states
 146  * that Divide-By-1.5 can cause failures, so we avoid that mode where
 147  * possible.
 148  *
 149  * ERRATA: There is an errata for the CS4270 where divide-by-1.5 does not
 150  * work if VD = 3.3V.  If this effects you, select the
 151  * CONFIG_SND_SOC_CS4270_VD33_ERRATA Kconfig option, and the driver will
 152  * never select any sample rates that require divide-by-1.5.
 153  */
 154 static struct {
 155         unsigned int ratio;
 156         u8 speed_mode;
 157         u8 mclk;
 158 } cs4270_mode_ratios[] = {
 159         {64, CS4270_MODE_4X, CS4270_MODE_DIV1},
 160 #ifndef CONFIG_SND_SOC_CS4270_VD33_ERRATA
 161         {96, CS4270_MODE_4X, CS4270_MODE_DIV15},
 162 #endif
 163         {128, CS4270_MODE_2X, CS4270_MODE_DIV1},
 164         {192, CS4270_MODE_4X, CS4270_MODE_DIV3},
 165         {256, CS4270_MODE_1X, CS4270_MODE_DIV1},
 166         {384, CS4270_MODE_2X, CS4270_MODE_DIV3},
 167         {512, CS4270_MODE_1X, CS4270_MODE_DIV2},
 168         {768, CS4270_MODE_1X, CS4270_MODE_DIV3},
 169         {1024, CS4270_MODE_1X, CS4270_MODE_DIV4}
 170 };
 171
 172 /* The number of MCLK/LRCK ratios supported by the CS4270 */
 173 #define NUM_MCLK_RATIOS         ARRAY_SIZE(cs4270_mode_ratios)
 174
 175 /*
 176  * Determine the CS4270 samples rates.
 177  *
 178  * 'freq' is the input frequency to MCLK.  The other parameters are ignored.
 179  *
 180  * The value of MCLK is used to determine which sample rates are supported
 181  * by the CS4270.  The ratio of MCLK / Fs must be equal to one of nine
 182  * support values: 64, 96, 128, 192, 256, 384, 512, 768, and 1024.
 183  *
 184  * This function calculates the nine ratios and determines which ones match
 185  * a standard sample rate.  If there's a match, then it is added to the list
 186  * of support sample rates.
 187  *
 188  * This function must be called by the machine driver's 'startup' function,
 189  * otherwise the list of supported sample rates will not be available in
 190  * time for ALSA.
 191  *
 192  * Note that in stand-alone mode, the sample rate is determined by input
 193  * pins M0, M1, MDIV1, and MDIV2.  Also in stand-alone mode, divide-by-3
 194  * is not a programmable option.  However, divide-by-3 is not an available
 195  * option in stand-alone mode.  This cases two problems: a ratio of 768 is
 196  * not available (it requires divide-by-3) and B) ratios 192 and 384 can
 197  * only be selected with divide-by-1.5, but there is an errate that make
 198  * this selection difficult.
 199  *
 200  * In addition, there is no mechanism for communicating with the machine
 201  * driver what the input settings can be.  This would need to be implemented
 202  * for stand-alone mode to work.
 203  */
 204 static int cs4270_set_dai_sysclk(struct snd_soc_dai *codec_dai,
 205                                  int clk_id, unsigned int freq, int dir)
 206 {
 207         struct snd_soc_codec *codec = codec_dai->codec;
 208         struct cs4270_private *cs4270 = codec->private_data;
 209         unsigned int rates = 0;
 210         unsigned int rate_min = -1;
 211         unsigned int rate_max = 0;
 212         unsigned int i;
 213
 214         cs4270->mclk = freq;
 215
 216         for (i = 0; i < NUM_MCLK_RATIOS; i++) {
 217                 unsigned int rate = freq / cs4270_mode_ratios[i].ratio;
 218                 rates |= snd_pcm_rate_to_rate_bit(rate);
 219                 if (rate < rate_min)
 220                         rate_min = rate;
 221                 if (rate > rate_max)
 222                         rate_max = rate;
 223         }
 224         /* FIXME: soc should support a rate list */
 225         rates &= ~SNDRV_PCM_RATE_KNOT;
 226
 227         if (!rates) {
 228                 printk(KERN_ERR "cs4270: could not find a valid sample rate\n");
 229                 return -EINVAL;
 230         }
 231
 232         codec_dai->playback.rates = rates;
 233         codec_dai->playback.rate_min = rate_min;
 234         codec_dai->playback.rate_max = rate_max;
 235
 236         codec_dai->capture.rates = rates;
 237         codec_dai->capture.rate_min = rate_min;
 238         codec_dai->capture.rate_max = rate_max;
 239
 240         return 0;
 241 }
 242
 243 /*
 244  * Configure the codec for the selected audio format
 245  *
 246  * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the
 247  * codec accordingly.
 248  *
 249  * Currently, this function only supports SND_SOC_DAIFMT_I2S and
 250  * SND_SOC_DAIFMT_LEFT_J.  The CS4270 codec also supports right-justified
 251  * data for playback only, but ASoC currently does not support different
 252  * formats for playback vs. record.
 253  */
 254 static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai,
 255                               unsigned int format)
 256 {
 257         struct snd_soc_codec *codec = codec_dai->codec;
 258         struct cs4270_private *cs4270 = codec->private_data;
 259         int ret = 0;
 260
 261         switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
 262         case SND_SOC_DAIFMT_I2S:
 263         case SND_SOC_DAIFMT_LEFT_J:
 264                 cs4270->mode = format & SND_SOC_DAIFMT_FORMAT_MASK;
 265                 break;
 266         default:
 267                 printk(KERN_ERR "cs4270: invalid DAI format\n");
 268                 ret = -EINVAL;
 269         }
 270
 271         return ret;
 272 }
 273
 274 /*
 275  * A list of addresses on which this CS4270 could use.  I2C addresses are
 276  * 7 bits.  For the CS4270, the upper four bits are always 1001, and the
 277  * lower three bits are determined via the AD2, AD1, and AD0 pins
 278  * (respectively).
 279  */
 280 static const unsigned short normal_i2c[] = {
 281         0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, I2C_CLIENT_END
 282 };
 283 I2C_CLIENT_INSMOD;
 284
 285 /*
 286  * Pre-fill the CS4270 register cache.
 287  *
 288  * We use the auto-increment feature of the CS4270 to read all registers in
 289  * one shot.
 290  */
 291 static int cs4270_fill_cache(struct snd_soc_codec *codec)
 292 {
 293         u8 *cache = codec->reg_cache;
 294         struct i2c_client *i2c_client = codec->control_data;
 295         s32 length;
 296
 297         length = i2c_smbus_read_i2c_block_data(i2c_client,
 298                 CS4270_FIRSTREG | 0x80, CS4270_NUMREGS, cache);
 299
 300         if (length != CS4270_NUMREGS) {
 301                 printk(KERN_ERR "cs4270: I2C read failure, addr=0x%x\n",
 302                        i2c_client->addr);
 303                 return -EIO;
 304         }
 305
 306         return 0;
 307 }
 308
 309 /*
 310  * Read from the CS4270 register cache.
 311  *
 312  * This CS4270 registers are cached to avoid excessive I2C I/O operations.
 313  * After the initial read to pre-fill the cache, the CS4270 never updates
 314  * the register values, so we won't have a cache coherncy problem.
 315  */
 316 static unsigned int cs4270_read_reg_cache(struct snd_soc_codec *codec,
 317         unsigned int reg)
 318 {
 319         u8 *cache = codec->reg_cache;
 320
 321         if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
 322                 return -EIO;
 323
 324         return cache[reg - CS4270_FIRSTREG];
 325 }
 326
 327 /*
 328  * Write to a CS4270 register via the I2C bus.
 329  *
 330  * This function writes the given value to the given CS4270 register, and
 331  * also updates the register cache.
 332  *
 333  * Note that we don't use the hw_write function pointer of snd_soc_codec.
 334  * That's because it's too clunky: the hw_write_t prototype does not match
 335  * i2c_smbus_write_byte_data(), and it's just another layer of overhead.
 336  */
 337 static int cs4270_i2c_write(struct snd_soc_codec *codec, unsigned int reg,
 338                             unsigned int value)
 339 {
 340         u8 *cache = codec->reg_cache;
 341
 342         if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
 343                 return -EIO;
 344
 345         /* Only perform an I2C operation if the new value is different */
 346         if (cache[reg - CS4270_FIRSTREG] != value) {
 347                 struct i2c_client *client = codec->control_data;
 348                 if (i2c_smbus_write_byte_data(client, reg, value)) {
 349                         printk(KERN_ERR "cs4270: I2C write failed\n");
 350                         return -EIO;
 351                 }
 352
 353                 /* We've written to the hardware, so update the cache */
 354                 cache[reg - CS4270_FIRSTREG] = value;
 355         }
 356
 357         return 0;
 358 }
 359
 360 /*
 361  * Program the CS4270 with the given hardware parameters.
 362  *
 363  * The .ops functions are used to provide board-specific data, like
 364  * input frequencies, to this driver.  This function takes that information,
 365  * combines it with the hardware parameters provided, and programs the
 366  * hardware accordingly.
 367  */
 368 static int cs4270_hw_params(struct snd_pcm_substream *substream,
 369                             struct snd_pcm_hw_params *params,
 370                             struct snd_soc_dai *dai)
 371 {
 372         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 373         struct snd_soc_device *socdev = rtd->socdev;
 374         struct snd_soc_codec *codec = socdev->codec;
 375         struct cs4270_private *cs4270 = codec->private_data;
 376         int ret;
 377         unsigned int i;
 378         unsigned int rate;
 379         unsigned int ratio;
 380         int reg;
 381
 382         /* Figure out which MCLK/LRCK ratio to use */
 383
 384         rate = params_rate(params);     /* Sampling rate, in Hz */
 385         ratio = cs4270->mclk / rate;    /* MCLK/LRCK ratio */
 386
 387         for (i = 0; i < NUM_MCLK_RATIOS; i++) {
 388                 if (cs4270_mode_ratios[i].ratio == ratio)
 389                         break;
 390         }
 391
 392         if (i == NUM_MCLK_RATIOS) {
 393                 /* We did not find a matching ratio */
 394                 printk(KERN_ERR "cs4270: could not find matching ratio\n");
 395                 return -EINVAL;
 396         }
 397
 398         /* Freeze and power-down the codec */
 399
 400         ret = snd_soc_write(codec, CS4270_PWRCTL, CS4270_PWRCTL_FREEZE |
 401                             CS4270_PWRCTL_PDN_ADC | CS4270_PWRCTL_PDN_DAC |
 402                             CS4270_PWRCTL_PDN);
 403         if (ret < 0) {
 404                 printk(KERN_ERR "cs4270: I2C write failed\n");
 405                 return ret;
 406         }
 407
 408         /* Program the mode control register */
 409
 410         reg = snd_soc_read(codec, CS4270_MODE);
 411         reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK);
 412         reg |= cs4270_mode_ratios[i].speed_mode | cs4270_mode_ratios[i].mclk;
 413
 414         ret = snd_soc_write(codec, CS4270_MODE, reg);
 415         if (ret < 0) {
 416                 printk(KERN_ERR "cs4270: I2C write failed\n");
 417                 return ret;
 418         }
 419
 420         /* Program the format register */
 421
 422         reg = snd_soc_read(codec, CS4270_FORMAT);
 423         reg &= ~(CS4270_FORMAT_DAC_MASK | CS4270_FORMAT_ADC_MASK);
 424
 425         switch (cs4270->mode) {
 426         case SND_SOC_DAIFMT_I2S:
 427                 reg |= CS4270_FORMAT_DAC_I2S | CS4270_FORMAT_ADC_I2S;
 428                 break;
 429         case SND_SOC_DAIFMT_LEFT_J:
 430                 reg |= CS4270_FORMAT_DAC_LJ | CS4270_FORMAT_ADC_LJ;
 431                 break;
 432         default:
 433                 printk(KERN_ERR "cs4270: unknown format\n");
 434                 return -EINVAL;
 435         }
 436
 437         ret = snd_soc_write(codec, CS4270_FORMAT, reg);
 438         if (ret < 0) {
 439                 printk(KERN_ERR "cs4270: I2C write failed\n");
 440                 return ret;
 441         }
 442
 443         /* Disable auto-mute.  This feature appears to be buggy, because in
 444            some situations, auto-mute will not deactivate when it should. */
 445
 446         reg = snd_soc_read(codec, CS4270_MUTE);
 447         reg &= ~CS4270_MUTE_AUTO;
 448         ret = snd_soc_write(codec, CS4270_MUTE, reg);
 449         if (ret < 0) {
 450                 printk(KERN_ERR "cs4270: I2C write failed\n");
 451                 return ret;
 452         }
 453
 454         /* Disable automatic volume control.  It's enabled by default, and
 455          * it causes volume change commands to be delayed, sometimes until
 456          * after playback has started.
 457          */
 458
 459         reg = cs4270_read_reg_cache(codec, CS4270_TRANS);
 460         reg &= ~(CS4270_TRANS_SOFT | CS4270_TRANS_ZERO);
 461         ret = cs4270_i2c_write(codec, CS4270_TRANS, reg);
 462         if (ret < 0) {
 463                 printk(KERN_ERR "I2C write failed\n");
 464                 return ret;
 465         }
 466
 467         /* Thaw and power-up the codec */
 468
 469         ret = snd_soc_write(codec, CS4270_PWRCTL, 0);
 470         if (ret < 0) {
 471                 printk(KERN_ERR "cs4270: I2C write failed\n");
 472                 return ret;
 473         }
 474
 475         return ret;
 476 }
 477
 478 #ifdef CONFIG_SND_SOC_CS4270_HWMUTE
 479
 480 /*
 481  * Set the CS4270 external mute
 482  *
 483  * This function toggles the mute bits in the MUTE register.  The CS4270's
 484  * mute capability is intended for external muting circuitry, so if the
 485  * board does not have the MUTEA or MUTEB pins connected to such circuitry,
 486  * then this function will do nothing.
 487  */
 488 static int cs4270_mute(struct snd_soc_dai *dai, int mute)
 489 {
 490         struct snd_soc_codec *codec = dai->codec;
 491         int reg6;
 492
 493         reg6 = snd_soc_read(codec, CS4270_MUTE);
 494
 495         if (mute)
 496                 reg6 |= CS4270_MUTE_ADC_A | CS4270_MUTE_ADC_B |
 497                         CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B;
 498         else
 499                 reg6 &= ~(CS4270_MUTE_ADC_A | CS4270_MUTE_ADC_B |
 500                           CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B);
 501
 502         return snd_soc_write(codec, CS4270_MUTE, reg6);
 503 }
 504
 505 #endif
 506
 507 static int cs4270_i2c_probe(struct i2c_client *, const struct i2c_device_id *);
 508
 509 /* A list of non-DAPM controls that the CS4270 supports */
 510 static const struct snd_kcontrol_new cs4270_snd_controls[] = {
 511         SOC_DOUBLE_R("Master Playback Volume",
 512                 CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 1)
 513 };
 514
 515 static const struct i2c_device_id cs4270_id[] = {
 516         {"cs4270", 0},
 517         {}
 518 };
 519 MODULE_DEVICE_TABLE(i2c, cs4270_id);
 520
 521 static struct i2c_driver cs4270_i2c_driver = {
 522         .driver = {
 523                 .name = "CS4270 I2C",
 524                 .owner = THIS_MODULE,
 525         },
 526         .id_table = cs4270_id,
 527         .probe = cs4270_i2c_probe,
 528 };
 529
 530 /*
 531  * Global variable to store socdev for i2c probe function.
 532  *
 533  * If struct i2c_driver had a private_data field, we wouldn't need to use
 534  * cs4270_socdec.  This is the only way to pass the socdev structure to
 535  * cs4270_i2c_probe().
 536  *
 537  * The real solution to cs4270_socdev is to create a mechanism
 538  * that maps I2C addresses to snd_soc_device structures.  Perhaps the
 539  * creation of the snd_soc_device object should be moved out of
 540  * cs4270_probe() and into cs4270_i2c_probe(), but that would make this
 541  * driver dependent on I2C.  The CS4270 supports "stand-alone" mode, whereby
 542  * the chip is *not* connected to the I2C bus, but is instead configured via
 543  * input pins.
 544  */
 545 static struct snd_soc_device *cs4270_socdev;
 546
 547 /*
 548  * Initialize the I2C interface of the CS4270
 549  *
 550  * This function is called for whenever the I2C subsystem finds a device
 551  * at a particular address.
 552  *
 553  * Note: snd_soc_new_pcms() must be called before this function can be called,
 554  * because of snd_ctl_add().
 555  */
 556 static int cs4270_i2c_probe(struct i2c_client *i2c_client,
 557         const struct i2c_device_id *id)
 558 {
 559         struct snd_soc_device *socdev = cs4270_socdev;
 560         struct snd_soc_codec *codec = socdev->codec;
 561         int i;
 562         int ret = 0;
 563
 564         /* Probing all possible addresses has one drawback: if there are
 565            multiple CS4270s on the bus, then you cannot specify which
 566            socdev is matched with which CS4270.  For now, we just reject
 567            this I2C device if the socdev already has one attached. */
 568         if (codec->control_data)
 569                 return -ENODEV;
 570
 571         /* Note: codec_dai->codec is NULL here */
 572
 573         codec->reg_cache = kzalloc(CS4270_NUMREGS, GFP_KERNEL);
 574         if (!codec->reg_cache) {
 575                 printk(KERN_ERR "cs4270: could not allocate register cache\n");
 576                 ret = -ENOMEM;
 577                 goto error;
 578         }
 579
 580         /* Verify that we have a CS4270 */
 581
 582         ret = i2c_smbus_read_byte_data(i2c_client, CS4270_CHIPID);
 583         if (ret < 0) {
 584                 printk(KERN_ERR "cs4270: failed to read I2C\n");
 585                 goto error;
 586         }
 587         /* The top four bits of the chip ID should be 1100. */
 588         if ((ret & 0xF0) != 0xC0) {
 589                 /* The device at this address is not a CS4270 codec */
 590                 ret = -ENODEV;
 591                 goto error;
 592         }
 593
 594         printk(KERN_INFO "cs4270: found device at I2C address %X\n",
 595                 i2c_client->addr);
 596         printk(KERN_INFO "cs4270: hardware revision %X\n", ret & 0xF);
 597
 598         codec->control_data = i2c_client;
 599         codec->read = cs4270_read_reg_cache;
 600         codec->write = cs4270_i2c_write;
 601         codec->reg_cache_size = CS4270_NUMREGS;
 602
 603         /* The I2C interface is set up, so pre-fill our register cache */
 604
 605         ret = cs4270_fill_cache(codec);
 606         if (ret < 0) {
 607                 printk(KERN_ERR "cs4270: failed to fill register cache\n");
 608                 goto error;
 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                 snd_soc_cnew(&cs4270_snd_controls[i], codec, NULL);
 616
 617                 ret = snd_ctl_add(codec->card, kctrl);
 618                 if (ret < 0)
 619                         goto error;
 620         }
 621
 622         i2c_set_clientdata(i2c_client, codec);
 623
 624         return 0;
 625
 626 error:
 627         codec->control_data = NULL;
 628
 629         kfree(codec->reg_cache);
 630         codec->reg_cache = NULL;
 631         codec->reg_cache_size = 0;
 632
 633         return ret;
 634 }
 635
 636 #endif /* USE_I2C*/
 637
 638 struct snd_soc_dai cs4270_dai = {
 639         .name = "CS4270",
 640         .playback = {
 641                 .stream_name = "Playback",
 642                 .channels_min = 1,
 643                 .channels_max = 2,
 644                 .rates = 0,
 645                 .formats = CS4270_FORMATS,
 646         },
 647         .capture = {
 648                 .stream_name = "Capture",
 649                 .channels_min = 1,
 650                 .channels_max = 2,
 651                 .rates = 0,
 652                 .formats = CS4270_FORMATS,
 653         },
 654 };
 655 EXPORT_SYMBOL_GPL(cs4270_dai);
 656
 657 /*
 658  * ASoC probe function
 659  *
 660  * This function is called when the machine driver calls
 661  * platform_device_add().
 662  */
 663 static int cs4270_probe(struct platform_device *pdev)
 664 {
 665         struct snd_soc_device *socdev = platform_get_drvdata(pdev);
 666         struct snd_soc_codec *codec;
 667         int ret = 0;
 668
 669         printk(KERN_INFO "CS4270 ALSA SoC Codec\n");
 670
 671         /* Allocate enough space for the snd_soc_codec structure
 672            and our private data together. */
 673         codec = kzalloc(ALIGN(sizeof(struct snd_soc_codec), 4) +
 674                         sizeof(struct cs4270_private), GFP_KERNEL);
 675         if (!codec) {
 676                 printk(KERN_ERR "cs4270: Could not allocate codec structure\n");
 677                 return -ENOMEM;
 678         }
 679
 680         mutex_init(&codec->mutex);
 681         INIT_LIST_HEAD(&codec->dapm_widgets);
 682         INIT_LIST_HEAD(&codec->dapm_paths);
 683
 684         codec->name = "CS4270";
 685         codec->owner = THIS_MODULE;
 686         codec->dai = &cs4270_dai;
 687         codec->num_dai = 1;
 688         codec->private_data = (void *) codec +
 689                 ALIGN(sizeof(struct snd_soc_codec), 4);
 690
 691         socdev->codec = codec;
 692
 693         /* Register PCMs */
 694
 695         ret = snd_soc_new_pcms(socdev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1);
 696         if (ret < 0) {
 697                 printk(KERN_ERR "cs4270: failed to create PCMs\n");
 698                 goto error_free_codec;
 699         }
 700
 701 #ifdef USE_I2C
 702         cs4270_socdev = socdev;
 703
 704         ret = i2c_add_driver(&cs4270_i2c_driver);
 705         if (ret) {
 706                 printk(KERN_ERR "cs4270: failed to attach driver");
 707                 goto error_free_pcms;
 708         }
 709
 710         /* Did we find a CS4270 on the I2C bus? */
 711         if (codec->control_data) {
 712                 /* Initialize codec ops */
 713                 cs4270_dai.ops.hw_params = cs4270_hw_params;
 714                 cs4270_dai.ops.set_sysclk = cs4270_set_dai_sysclk;
 715                 cs4270_dai.ops.set_fmt = cs4270_set_dai_fmt;
 716 #ifdef CONFIG_SND_SOC_CS4270_HWMUTE
 717                 cs4270_dai.ops.digital_mute = cs4270_mute;
 718 #endif
 719         } else
 720                 printk(KERN_INFO "cs4270: no I2C device found, "
 721                         "using stand-alone mode\n");
 722 #else
 723         printk(KERN_INFO "cs4270: I2C disabled, using stand-alone mode\n");
 724 #endif
 725
 726         ret = snd_soc_init_card(socdev);
 727         if (ret < 0) {
 728                 printk(KERN_ERR "cs4270: failed to register card\n");
 729                 goto error_del_driver;
 730         }
 731
 732         return 0;
 733
 734 error_del_driver:
 735 #ifdef USE_I2C
 736         i2c_del_driver(&cs4270_i2c_driver);
 737
 738 error_free_pcms:
 739 #endif
 740         snd_soc_free_pcms(socdev);
 741
 742 error_free_codec:
 743         kfree(socdev->codec);
 744         socdev->codec = NULL;
 745
 746         return ret;
 747 }
 748
 749 static int cs4270_remove(struct platform_device *pdev)
 750 {
 751         struct snd_soc_device *socdev = platform_get_drvdata(pdev);
 752
 753         snd_soc_free_pcms(socdev);
 754
 755 #ifdef USE_I2C
 756         i2c_del_driver(&cs4270_i2c_driver);
 757 #endif
 758
 759         kfree(socdev->codec);
 760         socdev->codec = NULL;
 761
 762         return 0;
 763 }
 764
 765 /*
 766  * ASoC codec device structure
 767  *
 768  * Assign this variable to the codec_dev field of the machine driver's
 769  * snd_soc_device structure.
 770  */
 771 struct snd_soc_codec_device soc_codec_device_cs4270 = {
 772         .probe =        cs4270_probe,
 773         .remove =       cs4270_remove
 774 };
 775 EXPORT_SYMBOL_GPL(soc_codec_device_cs4270);
 776
 777 static int __init cs4270_init(void)
 778 {
 779         return snd_soc_register_dai(&cs4270_dai);
 780 }
 781 module_init(cs4270_init);
 782
 783 static void __exit cs4270_exit(void)
 784 {
 785         snd_soc_unregister_dai(&cs4270_dai);
 786 }
 787 module_exit(cs4270_exit);
 788
 789 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
 790 MODULE_DESCRIPTION("Cirrus Logic CS4270 ALSA SoC Codec Driver");
 791 MODULE_LICENSE("GPL");