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 60 /* Bit masks for the CS4270 registers */ 61 #define CS4270_CHIPID_ID 0xF0 62 #define CS4270_CHIPID_REV 0x0F 63 #define CS4270_PWRCTL_FREEZE 0x80 64 #define CS4270_PWRCTL_PDN_ADC 0x20 65 #define CS4270_PWRCTL_PDN_DAC 0x02 66 #define CS4270_PWRCTL_PDN 0x01 67 #define CS4270_MODE_SPEED_MASK 0x30 68 #define CS4270_MODE_1X 0x00 69 #define CS4270_MODE_2X 0x10 70 #define CS4270_MODE_4X 0x20 71 #define CS4270_MODE_SLAVE 0x30 72 #define CS4270_MODE_DIV_MASK 0x0E 73 #define CS4270_MODE_DIV1 0x00 74 #define CS4270_MODE_DIV15 0x02 75 #define CS4270_MODE_DIV2 0x04 76 #define CS4270_MODE_DIV3 0x06 77 #define CS4270_MODE_DIV4 0x08 78 #define CS4270_MODE_POPGUARD 0x01 79 #define CS4270_FORMAT_FREEZE_A 0x80 80 #define CS4270_FORMAT_FREEZE_B 0x40 81 #define CS4270_FORMAT_LOOPBACK 0x20 82 #define CS4270_FORMAT_DAC_MASK 0x18 83 #define CS4270_FORMAT_DAC_LJ 0x00 84 #define CS4270_FORMAT_DAC_I2S 0x08 85 #define CS4270_FORMAT_DAC_RJ16 0x18 86 #define CS4270_FORMAT_DAC_RJ24 0x10 87 #define CS4270_FORMAT_ADC_MASK 0x01 88 #define CS4270_FORMAT_ADC_LJ 0x00 89 #define CS4270_FORMAT_ADC_I2S 0x01 90 #define CS4270_TRANS_ONE_VOL 0x80 91 #define CS4270_TRANS_SOFT 0x40 92 #define CS4270_TRANS_ZERO 0x20 93 #define CS4270_TRANS_INV_ADC_A 0x08 94 #define CS4270_TRANS_INV_ADC_B 0x10 95 #define CS4270_TRANS_INV_DAC_A 0x02 96 #define CS4270_TRANS_INV_DAC_B 0x04 97 #define CS4270_TRANS_DEEMPH 0x01 98 #define CS4270_MUTE_AUTO 0x20 99 #define CS4270_MUTE_ADC_A 0x08 100 #define CS4270_MUTE_ADC_B 0x10 101 #define CS4270_MUTE_POLARITY 0x04 102 #define CS4270_MUTE_DAC_A 0x01 103 #define CS4270_MUTE_DAC_B 0x02 104 105 /* Private data for the CS4270 */ 106 struct cs4270_private { 107 struct snd_soc_codec codec; 108 u8 reg_cache[CS4270_NUMREGS]; 109 unsigned int mclk; /* Input frequency of the MCLK pin */ 110 unsigned int mode; /* The mode (I2S or left-justified) */ 111 unsigned int slave_mode; 112 }; 113 114 /** 115 * struct cs4270_mode_ratios - clock ratio tables 116 * @ratio: the ratio of MCLK to the sample rate 117 * @speed_mode: the Speed Mode bits to set in the Mode Control register for 118 * this ratio 119 * @mclk: the Ratio Select bits to set in the Mode Control register for this 120 * ratio 121 * 122 * The data for this chart is taken from Table 5 of the CS4270 reference 123 * manual. 124 * 125 * This table is used to determine how to program the Mode Control register. 126 * It is also used by cs4270_set_dai_sysclk() to tell ALSA which sampling 127 * rates the CS4270 currently supports. 128 * 129 * @speed_mode is the corresponding bit pattern to be written to the 130 * MODE bits of the Mode Control Register 131 * 132 * @mclk is the corresponding bit pattern to be wirten to the MCLK bits of 133 * the Mode Control Register. 134 * 135 * In situations where a single ratio is represented by multiple speed 136 * modes, we favor the slowest speed. E.g, for a ratio of 128, we pick 137 * double-speed instead of quad-speed. However, the CS4270 errata states 138 * that divide-By-1.5 can cause failures, so we avoid that mode where 139 * possible. 140 * 141 * Errata: There is an errata for the CS4270 where divide-by-1.5 does not 142 * work if Vd is 3.3V. If this effects you, select the 143 * CONFIG_SND_SOC_CS4270_VD33_ERRATA Kconfig option, and the driver will 144 * never select any sample rates that require divide-by-1.5. 145 */ 146 struct cs4270_mode_ratios { 147 unsigned int ratio; 148 u8 speed_mode; 149 u8 mclk; 150 }; 151 152 static struct cs4270_mode_ratios cs4270_mode_ratios[] = { 153 {64, CS4270_MODE_4X, CS4270_MODE_DIV1}, 154 #ifndef CONFIG_SND_SOC_CS4270_VD33_ERRATA 155 {96, CS4270_MODE_4X, CS4270_MODE_DIV15}, 156 #endif 157 {128, CS4270_MODE_2X, CS4270_MODE_DIV1}, 158 {192, CS4270_MODE_4X, CS4270_MODE_DIV3}, 159 {256, CS4270_MODE_1X, CS4270_MODE_DIV1}, 160 {384, CS4270_MODE_2X, CS4270_MODE_DIV3}, 161 {512, CS4270_MODE_1X, CS4270_MODE_DIV2}, 162 {768, CS4270_MODE_1X, CS4270_MODE_DIV3}, 163 {1024, CS4270_MODE_1X, CS4270_MODE_DIV4} 164 }; 165 166 /* The number of MCLK/LRCK ratios supported by the CS4270 */ 167 #define NUM_MCLK_RATIOS ARRAY_SIZE(cs4270_mode_ratios) 168 169 /** 170 * cs4270_set_dai_sysclk - determine the CS4270 samples rates. 171 * @codec_dai: the codec DAI 172 * @clk_id: the clock ID (ignored) 173 * @freq: the MCLK input frequency 174 * @dir: the clock direction (ignored) 175 * 176 * This function is used to tell the codec driver what the input MCLK 177 * frequency is. 178 * 179 * The value of MCLK is used to determine which sample rates are supported 180 * by the CS4270. The ratio of MCLK / Fs must be equal to one of nine 181 * supported values - 64, 96, 128, 192, 256, 384, 512, 768, and 1024. 182 * 183 * This function calculates the nine ratios and determines which ones match 184 * a standard sample rate. If there's a match, then it is added to the list 185 * of supported sample rates. 186 * 187 * This function must be called by the machine driver's 'startup' function, 188 * otherwise the list of supported sample rates will not be available in 189 * time for ALSA. 190 */ 191 static int cs4270_set_dai_sysclk(struct snd_soc_dai *codec_dai, 192 int clk_id, unsigned int freq, int dir) 193 { 194 struct snd_soc_codec *codec = codec_dai->codec; 195 struct cs4270_private *cs4270 = codec->private_data; 196 unsigned int rates = 0; 197 unsigned int rate_min = -1; 198 unsigned int rate_max = 0; 199 unsigned int i; 200 201 cs4270->mclk = freq; 202 203 for (i = 0; i < NUM_MCLK_RATIOS; i++) { 204 unsigned int rate = freq / cs4270_mode_ratios[i].ratio; 205 rates |= snd_pcm_rate_to_rate_bit(rate); 206 if (rate < rate_min) 207 rate_min = rate; 208 if (rate > rate_max) 209 rate_max = rate; 210 } 211 /* FIXME: soc should support a rate list */ 212 rates &= ~SNDRV_PCM_RATE_KNOT; 213 214 if (!rates) { 215 dev_err(codec->dev, "could not find a valid sample rate\n"); 216 return -EINVAL; 217 } 218 219 codec_dai->playback.rates = rates; 220 codec_dai->playback.rate_min = rate_min; 221 codec_dai->playback.rate_max = rate_max; 222 223 codec_dai->capture.rates = rates; 224 codec_dai->capture.rate_min = rate_min; 225 codec_dai->capture.rate_max = rate_max; 226 227 return 0; 228 } 229 230 /** 231 * cs4270_set_dai_fmt - configure the codec for the selected audio format 232 * @codec_dai: the codec DAI 233 * @format: a SND_SOC_DAIFMT_x value indicating the data format 234 * 235 * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the 236 * codec accordingly. 237 * 238 * Currently, this function only supports SND_SOC_DAIFMT_I2S and 239 * SND_SOC_DAIFMT_LEFT_J. The CS4270 codec also supports right-justified 240 * data for playback only, but ASoC currently does not support different 241 * formats for playback vs. record. 242 */ 243 static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai, 244 unsigned int format) 245 { 246 struct snd_soc_codec *codec = codec_dai->codec; 247 struct cs4270_private *cs4270 = codec->private_data; 248 int ret = 0; 249 250 /* set DAI format */ 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 dev_err(codec->dev, "invalid dai format\n"); 258 ret = -EINVAL; 259 } 260 261 /* set master/slave audio interface */ 262 switch (format & SND_SOC_DAIFMT_MASTER_MASK) { 263 case SND_SOC_DAIFMT_CBS_CFS: 264 cs4270->slave_mode = 1; 265 break; 266 case SND_SOC_DAIFMT_CBM_CFM: 267 cs4270->slave_mode = 0; 268 break; 269 default: 270 /* all other modes are unsupported by the hardware */ 271 ret = -EINVAL; 272 } 273 274 return ret; 275 } 276 277 /** 278 * cs4270_fill_cache - pre-fill the CS4270 register cache. 279 * @codec: the codec for this CS4270 280 * 281 * This function fills in the CS4270 register cache by reading the register 282 * values from the hardware. 283 * 284 * This CS4270 registers are cached to avoid excessive I2C I/O operations. 285 * After the initial read to pre-fill the cache, the CS4270 never updates 286 * the register values, so we won't have a cache coherency problem. 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 dev_err(codec->dev, "i2c read failure, addr=0x%x\n", 302 i2c_client->addr); 303 return -EIO; 304 } 305 306 return 0; 307 } 308 309 /** 310 * cs4270_read_reg_cache - read from the CS4270 register cache. 311 * @codec: the codec for this CS4270 312 * @reg: the register to read 313 * 314 * This function returns the value for a given register. It reads only from 315 * the register cache, not the hardware itself. 316 * 317 * This CS4270 registers are cached to avoid excessive I2C I/O operations. 318 * After the initial read to pre-fill the cache, the CS4270 never updates 319 * the register values, so we won't have a cache coherency problem. 320 */ 321 static unsigned int cs4270_read_reg_cache(struct snd_soc_codec *codec, 322 unsigned int reg) 323 { 324 u8 *cache = codec->reg_cache; 325 326 if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG)) 327 return -EIO; 328 329 return cache[reg - CS4270_FIRSTREG]; 330 } 331 332 /** 333 * cs4270_i2c_write - write to a CS4270 register via the I2C bus. 334 * @codec: the codec for this CS4270 335 * @reg: the register to write 336 * @value: the value to write to the register 337 * 338 * This function writes the given value to the given CS4270 register, and 339 * also updates the register cache. 340 * 341 * Note that we don't use the hw_write function pointer of snd_soc_codec. 342 * That's because it's too clunky: the hw_write_t prototype does not match 343 * i2c_smbus_write_byte_data(), and it's just another layer of overhead. 344 */ 345 static int cs4270_i2c_write(struct snd_soc_codec *codec, unsigned int reg, 346 unsigned int value) 347 { 348 u8 *cache = codec->reg_cache; 349 350 if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG)) 351 return -EIO; 352 353 /* Only perform an I2C operation if the new value is different */ 354 if (cache[reg - CS4270_FIRSTREG] != value) { 355 struct i2c_client *client = codec->control_data; 356 if (i2c_smbus_write_byte_data(client, reg, value)) { 357 dev_err(codec->dev, "i2c write failed\n"); 358 return -EIO; 359 } 360 361 /* We've written to the hardware, so update the cache */ 362 cache[reg - CS4270_FIRSTREG] = value; 363 } 364 365 return 0; 366 } 367 368 /** 369 * cs4270_hw_params - program the CS4270 with the given hardware parameters. 370 * @substream: the audio stream 371 * @params: the hardware parameters to set 372 * @dai: the SOC DAI (ignored) 373 * 374 * This function programs the hardware with the values provided. 375 * Specifically, the sample rate and the data format. 376 * 377 * The .ops functions are used to provide board-specific data, like input 378 * frequencies, to this driver. This function takes that information, 379 * combines it with the hardware parameters provided, and programs the 380 * hardware accordingly. 381 */ 382 static int cs4270_hw_params(struct snd_pcm_substream *substream, 383 struct snd_pcm_hw_params *params, 384 struct snd_soc_dai *dai) 385 { 386 struct snd_soc_pcm_runtime *rtd = substream->private_data; 387 struct snd_soc_device *socdev = rtd->socdev; 388 struct snd_soc_codec *codec = socdev->card->codec; 389 struct cs4270_private *cs4270 = codec->private_data; 390 int ret; 391 unsigned int i; 392 unsigned int rate; 393 unsigned int ratio; 394 int reg; 395 396 /* Figure out which MCLK/LRCK ratio to use */ 397 398 rate = params_rate(params); /* Sampling rate, in Hz */ 399 ratio = cs4270->mclk / rate; /* MCLK/LRCK ratio */ 400 401 for (i = 0; i < NUM_MCLK_RATIOS; i++) { 402 if (cs4270_mode_ratios[i].ratio == ratio) 403 break; 404 } 405 406 if (i == NUM_MCLK_RATIOS) { 407 /* We did not find a matching ratio */ 408 dev_err(codec->dev, "could not find matching ratio\n"); 409 return -EINVAL; 410 } 411 412 /* Set the sample rate */ 413 414 reg = snd_soc_read(codec, CS4270_MODE); 415 reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK); 416 reg |= cs4270_mode_ratios[i].mclk; 417 418 if (cs4270->slave_mode) 419 reg |= CS4270_MODE_SLAVE; 420 else 421 reg |= cs4270_mode_ratios[i].speed_mode; 422 423 ret = snd_soc_write(codec, CS4270_MODE, reg); 424 if (ret < 0) { 425 dev_err(codec->dev, "i2c write failed\n"); 426 return ret; 427 } 428 429 /* Set the DAI format */ 430 431 reg = snd_soc_read(codec, CS4270_FORMAT); 432 reg &= ~(CS4270_FORMAT_DAC_MASK | CS4270_FORMAT_ADC_MASK); 433 434 switch (cs4270->mode) { 435 case SND_SOC_DAIFMT_I2S: 436 reg |= CS4270_FORMAT_DAC_I2S | CS4270_FORMAT_ADC_I2S; 437 break; 438 case SND_SOC_DAIFMT_LEFT_J: 439 reg |= CS4270_FORMAT_DAC_LJ | CS4270_FORMAT_ADC_LJ; 440 break; 441 default: 442 dev_err(codec->dev, "unknown dai format\n"); 443 return -EINVAL; 444 } 445 446 ret = snd_soc_write(codec, CS4270_FORMAT, reg); 447 if (ret < 0) { 448 dev_err(codec->dev, "i2c write failed\n"); 449 return ret; 450 } 451 452 return ret; 453 } 454 455 /** 456 * cs4270_mute - enable/disable the CS4270 external mute 457 * @dai: the SOC DAI 458 * @mute: 0 = disable mute, 1 = enable mute 459 * 460 * This function toggles the mute bits in the MUTE register. The CS4270's 461 * mute capability is intended for external muting circuitry, so if the 462 * board does not have the MUTEA or MUTEB pins connected to such circuitry, 463 * then this function will do nothing. 464 */ 465 static int cs4270_mute(struct snd_soc_dai *dai, int mute) 466 { 467 struct snd_soc_codec *codec = dai->codec; 468 int reg6; 469 470 reg6 = snd_soc_read(codec, CS4270_MUTE); 471 472 if (mute) 473 reg6 |= CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B; 474 else 475 reg6 &= ~(CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B); 476 477 return snd_soc_write(codec, CS4270_MUTE, reg6); 478 } 479 480 /* A list of non-DAPM controls that the CS4270 supports */ 481 static const struct snd_kcontrol_new cs4270_snd_controls[] = { 482 SOC_DOUBLE_R("Master Playback Volume", 483 CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 1), 484 SOC_SINGLE("Digital Sidetone Switch", CS4270_FORMAT, 5, 1, 0), 485 SOC_SINGLE("Soft Ramp Switch", CS4270_TRANS, 6, 1, 0), 486 SOC_SINGLE("Zero Cross Switch", CS4270_TRANS, 5, 1, 0), 487 SOC_SINGLE("Popguard Switch", CS4270_MODE, 0, 1, 1), 488 SOC_SINGLE("Auto-Mute Switch", CS4270_MUTE, 5, 1, 0), 489 SOC_DOUBLE("Master Capture Switch", CS4270_MUTE, 3, 4, 1, 0) 490 }; 491 492 /* 493 * cs4270_codec - global variable to store codec for the ASoC probe function 494 * 495 * If struct i2c_driver had a private_data field, we wouldn't need to use 496 * cs4270_codec. This is the only way to pass the codec structure from 497 * cs4270_i2c_probe() to cs4270_probe(). Unfortunately, there is no good 498 * way to synchronize these two functions. cs4270_i2c_probe() can be called 499 * multiple times before cs4270_probe() is called even once. So for now, we 500 * also only allow cs4270_i2c_probe() to be run once. That means that we do 501 * not support more than one cs4270 device in the system, at least for now. 502 */ 503 static struct snd_soc_codec *cs4270_codec; 504 505 static struct snd_soc_dai_ops cs4270_dai_ops = { 506 .hw_params = cs4270_hw_params, 507 .set_sysclk = cs4270_set_dai_sysclk, 508 .set_fmt = cs4270_set_dai_fmt, 509 .digital_mute = cs4270_mute, 510 }; 511 512 struct snd_soc_dai cs4270_dai = { 513 .name = "cs4270", 514 .playback = { 515 .stream_name = "Playback", 516 .channels_min = 1, 517 .channels_max = 2, 518 .rates = 0, 519 .formats = CS4270_FORMATS, 520 }, 521 .capture = { 522 .stream_name = "Capture", 523 .channels_min = 1, 524 .channels_max = 2, 525 .rates = 0, 526 .formats = CS4270_FORMATS, 527 }, 528 .ops = &cs4270_dai_ops, 529 }; 530 EXPORT_SYMBOL_GPL(cs4270_dai); 531 532 /** 533 * cs4270_probe - ASoC probe function 534 * @pdev: platform device 535 * 536 * This function is called when ASoC has all the pieces it needs to 537 * instantiate a sound driver. 538 */ 539 static int cs4270_probe(struct platform_device *pdev) 540 { 541 struct snd_soc_device *socdev = platform_get_drvdata(pdev); 542 struct snd_soc_codec *codec = cs4270_codec; 543 int ret; 544 545 /* Connect the codec to the socdev. snd_soc_new_pcms() needs this. */ 546 socdev->card->codec = codec; 547 548 /* Register PCMs */ 549 ret = snd_soc_new_pcms(socdev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1); 550 if (ret < 0) { 551 dev_err(codec->dev, "failed to create pcms\n"); 552 return ret; 553 } 554 555 /* Add the non-DAPM controls */ 556 ret = snd_soc_add_controls(codec, cs4270_snd_controls, 557 ARRAY_SIZE(cs4270_snd_controls)); 558 if (ret < 0) { 559 dev_err(codec->dev, "failed to add controls\n"); 560 goto error_free_pcms; 561 } 562 563 /* And finally, register the socdev */ 564 ret = snd_soc_init_card(socdev); 565 if (ret < 0) { 566 dev_err(codec->dev, "failed to register card\n"); 567 goto error_free_pcms; 568 } 569 570 return 0; 571 572 error_free_pcms: 573 snd_soc_free_pcms(socdev); 574 575 return ret; 576 } 577 578 /** 579 * cs4270_remove - ASoC remove function 580 * @pdev: platform device 581 * 582 * This function is the counterpart to cs4270_probe(). 583 */ 584 static int cs4270_remove(struct platform_device *pdev) 585 { 586 struct snd_soc_device *socdev = platform_get_drvdata(pdev); 587 588 snd_soc_free_pcms(socdev); 589 590 return 0; 591 }; 592 593 /** 594 * cs4270_i2c_probe - initialize the I2C interface of the CS4270 595 * @i2c_client: the I2C client object 596 * @id: the I2C device ID (ignored) 597 * 598 * This function is called whenever the I2C subsystem finds a device that 599 * matches the device ID given via a prior call to i2c_add_driver(). 600 */ 601 static int cs4270_i2c_probe(struct i2c_client *i2c_client, 602 const struct i2c_device_id *id) 603 { 604 struct snd_soc_codec *codec; 605 struct cs4270_private *cs4270; 606 unsigned int reg; 607 int ret; 608 609 /* For now, we only support one cs4270 device in the system. See the 610 * comment for cs4270_codec. 611 */ 612 if (cs4270_codec) { 613 dev_err(&i2c_client->dev, "ignoring CS4270 at addr %X\n", 614 i2c_client->addr); 615 dev_err(&i2c_client->dev, "only one per board allowed\n"); 616 /* Should we return something other than ENODEV here? */ 617 return -ENODEV; 618 } 619 620 /* Verify that we have a CS4270 */ 621 622 ret = i2c_smbus_read_byte_data(i2c_client, CS4270_CHIPID); 623 if (ret < 0) { 624 dev_err(&i2c_client->dev, "failed to read i2c at addr %X\n", 625 i2c_client->addr); 626 return ret; 627 } 628 /* The top four bits of the chip ID should be 1100. */ 629 if ((ret & 0xF0) != 0xC0) { 630 dev_err(&i2c_client->dev, "device at addr %X is not a CS4270\n", 631 i2c_client->addr); 632 return -ENODEV; 633 } 634 635 dev_info(&i2c_client->dev, "found device at i2c address %X\n", 636 i2c_client->addr); 637 dev_info(&i2c_client->dev, "hardware revision %X\n", ret & 0xF); 638 639 /* Allocate enough space for the snd_soc_codec structure 640 and our private data together. */ 641 cs4270 = kzalloc(sizeof(struct cs4270_private), GFP_KERNEL); 642 if (!cs4270) { 643 dev_err(&i2c_client->dev, "could not allocate codec\n"); 644 return -ENOMEM; 645 } 646 codec = &cs4270->codec; 647 648 mutex_init(&codec->mutex); 649 INIT_LIST_HEAD(&codec->dapm_widgets); 650 INIT_LIST_HEAD(&codec->dapm_paths); 651 652 codec->dev = &i2c_client->dev; 653 codec->name = "CS4270"; 654 codec->owner = THIS_MODULE; 655 codec->dai = &cs4270_dai; 656 codec->num_dai = 1; 657 codec->private_data = cs4270; 658 codec->control_data = i2c_client; 659 codec->read = cs4270_read_reg_cache; 660 codec->write = cs4270_i2c_write; 661 codec->reg_cache = cs4270->reg_cache; 662 codec->reg_cache_size = CS4270_NUMREGS; 663 664 /* The I2C interface is set up, so pre-fill our register cache */ 665 666 ret = cs4270_fill_cache(codec); 667 if (ret < 0) { 668 dev_err(&i2c_client->dev, "failed to fill register cache\n"); 669 goto error_free_codec; 670 } 671 672 /* Disable auto-mute. This feature appears to be buggy. In some 673 * situations, auto-mute will not deactivate when it should, so we want 674 * this feature disabled by default. An application (e.g. alsactl) can 675 * re-enabled it by using the controls. 676 */ 677 678 reg = cs4270_read_reg_cache(codec, CS4270_MUTE); 679 reg &= ~CS4270_MUTE_AUTO; 680 ret = cs4270_i2c_write(codec, CS4270_MUTE, reg); 681 if (ret < 0) { 682 dev_err(&i2c_client->dev, "i2c write failed\n"); 683 return ret; 684 } 685 686 /* Disable automatic volume control. The hardware enables, and it 687 * causes volume change commands to be delayed, sometimes until after 688 * playback has started. An application (e.g. alsactl) can 689 * re-enabled it by using the controls. 690 */ 691 692 reg = cs4270_read_reg_cache(codec, CS4270_TRANS); 693 reg &= ~(CS4270_TRANS_SOFT | CS4270_TRANS_ZERO); 694 ret = cs4270_i2c_write(codec, CS4270_TRANS, reg); 695 if (ret < 0) { 696 dev_err(&i2c_client->dev, "i2c write failed\n"); 697 return ret; 698 } 699 700 /* Initialize the DAI. Normally, we'd prefer to have a kmalloc'd DAI 701 * structure for each CS4270 device, but the machine driver needs to 702 * have a pointer to the DAI structure, so for now it must be a global 703 * variable. 704 */ 705 cs4270_dai.dev = &i2c_client->dev; 706 707 /* Register the DAI. If all the other ASoC driver have already 708 * registered, then this will call our probe function, so 709 * cs4270_codec needs to be ready. 710 */ 711 cs4270_codec = codec; 712 ret = snd_soc_register_dai(&cs4270_dai); 713 if (ret < 0) { 714 dev_err(&i2c_client->dev, "failed to register DAIe\n"); 715 goto error_free_codec; 716 } 717 718 i2c_set_clientdata(i2c_client, cs4270); 719 720 return 0; 721 722 error_free_codec: 723 kfree(cs4270); 724 cs4270_codec = NULL; 725 cs4270_dai.dev = NULL; 726 727 return ret; 728 } 729 730 /** 731 * cs4270_i2c_remove - remove an I2C device 732 * @i2c_client: the I2C client object 733 * 734 * This function is the counterpart to cs4270_i2c_probe(). 735 */ 736 static int cs4270_i2c_remove(struct i2c_client *i2c_client) 737 { 738 struct cs4270_private *cs4270 = i2c_get_clientdata(i2c_client); 739 740 kfree(cs4270); 741 cs4270_codec = NULL; 742 cs4270_dai.dev = NULL; 743 744 return 0; 745 } 746 747 /* 748 * cs4270_id - I2C device IDs supported by this driver 749 */ 750 static struct i2c_device_id cs4270_id[] = { 751 {"cs4270", 0}, 752 {} 753 }; 754 MODULE_DEVICE_TABLE(i2c, cs4270_id); 755 756 /* 757 * cs4270_i2c_driver - I2C device identification 758 * 759 * This structure tells the I2C subsystem how to identify and support a 760 * given I2C device type. 761 */ 762 static struct i2c_driver cs4270_i2c_driver = { 763 .driver = { 764 .name = "cs4270", 765 .owner = THIS_MODULE, 766 }, 767 .id_table = cs4270_id, 768 .probe = cs4270_i2c_probe, 769 .remove = cs4270_i2c_remove, 770 }; 771 772 /* 773 * ASoC codec device structure 774 * 775 * Assign this variable to the codec_dev field of the machine driver's 776 * snd_soc_device structure. 777 */ 778 struct snd_soc_codec_device soc_codec_device_cs4270 = { 779 .probe = cs4270_probe, 780 .remove = cs4270_remove 781 }; 782 EXPORT_SYMBOL_GPL(soc_codec_device_cs4270); 783 784 static int __init cs4270_init(void) 785 { 786 pr_info("Cirrus Logic CS4270 ALSA SoC Codec Driver\n"); 787 788 return i2c_add_driver(&cs4270_i2c_driver); 789 } 790 module_init(cs4270_init); 791 792 static void __exit cs4270_exit(void) 793 { 794 i2c_del_driver(&cs4270_i2c_driver); 795 } 796 module_exit(cs4270_exit); 797 798 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>"); 799 MODULE_DESCRIPTION("Cirrus Logic CS4270 ALSA SoC Codec Driver"); 800 MODULE_LICENSE("GPL"); 801