drivers/mfd/wm8994-core.c

   1 /*
   2  * wm8994-core.c  --  Device access for Wolfson WM8994
   3  *
   4  * Copyright 2009 Wolfson Microelectronics PLC.
   5  *
   6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   7  *
   8  *  This program is free software; you can redistribute  it and/or modify it
   9  *  under  the terms of  the GNU General  Public License as published by the
  10  *  Free Software Foundation;  either version 2 of the  License, or (at your
  11  *  option) any later version.
  12  *
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/slab.h>
  18 #include <linux/i2c.h>
  19 #include <linux/err.h>
  20 #include <linux/delay.h>
  21 #include <linux/mfd/core.h>
  22 #include <linux/pm_runtime.h>
  23 #include <linux/regmap.h>
  24 #include <linux/regulator/consumer.h>
  25 #include <linux/regulator/machine.h>
  26
  27 #include <linux/mfd/wm8994/core.h>
  28 #include <linux/mfd/wm8994/pdata.h>
  29 #include <linux/mfd/wm8994/registers.h>
  30
  31 #include "wm8994.h"
  32
  33 /**
  34  * wm8994_reg_read: Read a single WM8994 register.
  35  *
  36  * @wm8994: Device to read from.
  37  * @reg: Register to read.
  38  */
  39 int wm8994_reg_read(struct wm8994 *wm8994, unsigned short reg)
  40 {
  41         unsigned int val;
  42         int ret;
  43
  44         ret = regmap_read(wm8994->regmap, reg, &val);
  45
  46         if (ret < 0)
  47                 return ret;
  48         else
  49                 return val;
  50 }
  51 EXPORT_SYMBOL_GPL(wm8994_reg_read);
  52
  53 /**
  54  * wm8994_bulk_read: Read multiple WM8994 registers
  55  *
  56  * @wm8994: Device to read from
  57  * @reg: First register
  58  * @count: Number of registers
  59  * @buf: Buffer to fill.  The data will be returned big endian.
  60  */
  61 int wm8994_bulk_read(struct wm8994 *wm8994, unsigned short reg,
  62                      int count, u16 *buf)
  63 {
  64         return regmap_bulk_read(wm8994->regmap, reg, buf, count);
  65 }
  66
  67 /**
  68  * wm8994_reg_write: Write a single WM8994 register.
  69  *
  70  * @wm8994: Device to write to.
  71  * @reg: Register to write to.
  72  * @val: Value to write.
  73  */
  74 int wm8994_reg_write(struct wm8994 *wm8994, unsigned short reg,
  75                      unsigned short val)
  76 {
  77         return regmap_write(wm8994->regmap, reg, val);
  78 }
  79 EXPORT_SYMBOL_GPL(wm8994_reg_write);
  80
  81 /**
  82  * wm8994_bulk_write: Write multiple WM8994 registers
  83  *
  84  * @wm8994: Device to write to
  85  * @reg: First register
  86  * @count: Number of registers
  87  * @buf: Buffer to write from.  Data must be big-endian formatted.
  88  */
  89 int wm8994_bulk_write(struct wm8994 *wm8994, unsigned short reg,
  90                       int count, const u16 *buf)
  91 {
  92         return regmap_raw_write(wm8994->regmap, reg, buf, count * sizeof(u16));
  93 }
  94 EXPORT_SYMBOL_GPL(wm8994_bulk_write);
  95
  96 /**
  97  * wm8994_set_bits: Set the value of a bitfield in a WM8994 register
  98  *
  99  * @wm8994: Device to write to.
 100  * @reg: Register to write to.
 101  * @mask: Mask of bits to set.
 102  * @val: Value to set (unshifted)
 103  */
 104 int wm8994_set_bits(struct wm8994 *wm8994, unsigned short reg,
 105                     unsigned short mask, unsigned short val)
 106 {
 107         return regmap_update_bits(wm8994->regmap, reg, mask, val);
 108 }
 109 EXPORT_SYMBOL_GPL(wm8994_set_bits);
 110
 111 static struct mfd_cell wm8994_regulator_devs[] = {
 112         {
 113                 .name = "wm8994-ldo",
 114                 .id = 1,
 115                 .pm_runtime_no_callbacks = true,
 116         },
 117         {
 118                 .name = "wm8994-ldo",
 119                 .id = 2,
 120                 .pm_runtime_no_callbacks = true,
 121         },
 122 };
 123
 124 static struct resource wm8994_codec_resources[] = {
 125         {
 126                 .start = WM8994_IRQ_TEMP_SHUT,
 127                 .end   = WM8994_IRQ_TEMP_WARN,
 128                 .flags = IORESOURCE_IRQ,
 129         },
 130 };
 131
 132 static struct resource wm8994_gpio_resources[] = {
 133         {
 134                 .start = WM8994_IRQ_GPIO(1),
 135                 .end   = WM8994_IRQ_GPIO(11),
 136                 .flags = IORESOURCE_IRQ,
 137         },
 138 };
 139
 140 static struct mfd_cell wm8994_devs[] = {
 141         {
 142                 .name = "wm8994-codec",
 143                 .num_resources = ARRAY_SIZE(wm8994_codec_resources),
 144                 .resources = wm8994_codec_resources,
 145         },
 146
 147         {
 148                 .name = "wm8994-gpio",
 149                 .num_resources = ARRAY_SIZE(wm8994_gpio_resources),
 150                 .resources = wm8994_gpio_resources,
 151                 .pm_runtime_no_callbacks = true,
 152         },
 153 };
 154
 155 /*
 156  * Supplies for the main bulk of CODEC; the LDO supplies are ignored
 157  * and should be handled via the standard regulator API supply
 158  * management.
 159  */
 160 static const char *wm1811_main_supplies[] = {
 161         "DBVDD1",
 162         "DBVDD2",
 163         "DBVDD3",
 164         "DCVDD",
 165         "AVDD1",
 166         "AVDD2",
 167         "CPVDD",
 168         "SPKVDD1",
 169         "SPKVDD2",
 170 };
 171
 172 static const char *wm8994_main_supplies[] = {
 173         "DBVDD",
 174         "DCVDD",
 175         "AVDD1",
 176         "AVDD2",
 177         "CPVDD",
 178         "SPKVDD1",
 179         "SPKVDD2",
 180 };
 181
 182 static const char *wm8958_main_supplies[] = {
 183         "DBVDD1",
 184         "DBVDD2",
 185         "DBVDD3",
 186         "DCVDD",
 187         "AVDD1",
 188         "AVDD2",
 189         "CPVDD",
 190         "SPKVDD1",
 191         "SPKVDD2",
 192 };
 193
 194 #ifdef CONFIG_PM
 195 static int wm8994_suspend(struct device *dev)
 196 {
 197         struct wm8994 *wm8994 = dev_get_drvdata(dev);
 198         int ret;
 199
 200         /* Don't actually go through with the suspend if the CODEC is
 201          * still active (eg, for audio passthrough from CP. */
 202         ret = wm8994_reg_read(wm8994, WM8994_POWER_MANAGEMENT_1);
 203         if (ret < 0) {
 204                 dev_err(dev, "Failed to read power status: %d\n", ret);
 205         } else if (ret & WM8994_VMID_SEL_MASK) {
 206                 dev_dbg(dev, "CODEC still active, ignoring suspend\n");
 207                 return 0;
 208         }
 209
 210         ret = wm8994_reg_read(wm8994, WM8994_POWER_MANAGEMENT_4);
 211         if (ret < 0) {
 212                 dev_err(dev, "Failed to read power status: %d\n", ret);
 213         } else if (ret & (WM8994_AIF2ADCL_ENA | WM8994_AIF2ADCR_ENA |
 214                           WM8994_AIF1ADC2L_ENA | WM8994_AIF1ADC2R_ENA |
 215                           WM8994_AIF1ADC1L_ENA | WM8994_AIF1ADC1R_ENA)) {
 216                 dev_dbg(dev, "CODEC still active, ignoring suspend\n");
 217                 return 0;
 218         }
 219
 220         ret = wm8994_reg_read(wm8994, WM8994_POWER_MANAGEMENT_5);
 221         if (ret < 0) {
 222                 dev_err(dev, "Failed to read power status: %d\n", ret);
 223         } else if (ret & (WM8994_AIF2DACL_ENA | WM8994_AIF2DACR_ENA |
 224                           WM8994_AIF1DAC2L_ENA | WM8994_AIF1DAC2R_ENA |
 225                           WM8994_AIF1DAC1L_ENA | WM8994_AIF1DAC1R_ENA)) {
 226                 dev_dbg(dev, "CODEC still active, ignoring suspend\n");
 227                 return 0;
 228         }
 229
 230         switch (wm8994->type) {
 231         case WM8958:
 232                 ret = wm8994_reg_read(wm8994, WM8958_MIC_DETECT_1);
 233                 if (ret < 0) {
 234                         dev_err(dev, "Failed to read power status: %d\n", ret);
 235                 } else if (ret & WM8958_MICD_ENA) {
 236                         dev_dbg(dev, "CODEC still active, ignoring suspend\n");
 237                         return 0;
 238                 }
 239                 break;
 240         default:
 241                 break;
 242         }
 243
 244         switch (wm8994->type) {
 245         case WM1811:
 246                 ret = wm8994_reg_read(wm8994, WM8994_ANTIPOP_2);
 247                 if (ret < 0) {
 248                         dev_err(dev, "Failed to read jackdet: %d\n", ret);
 249                 } else if (ret & WM1811_JACKDET_MODE_MASK) {
 250                         dev_dbg(dev, "CODEC still active, ignoring suspend\n");
 251                         return 0;
 252                 }
 253                 break;
 254         default:
 255                 break;
 256         }
 257
 258         /* Disable LDO pulldowns while the device is suspended if we
 259          * don't know that something will be driving them. */
 260         if (!wm8994->ldo_ena_always_driven)
 261                 wm8994_set_bits(wm8994, WM8994_PULL_CONTROL_2,
 262                                 WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD,
 263                                 WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD);
 264
 265         /* Explicitly put the device into reset in case regulators
 266          * don't get disabled in order to ensure consistent restart.
 267          */
 268         wm8994_reg_write(wm8994, WM8994_SOFTWARE_RESET,
 269                          wm8994_reg_read(wm8994, WM8994_SOFTWARE_RESET));
 270
 271         regcache_cache_only(wm8994->regmap, true);
 272         regcache_mark_dirty(wm8994->regmap);
 273
 274         wm8994->suspended = true;
 275
 276         ret = regulator_bulk_disable(wm8994->num_supplies,
 277                                      wm8994->supplies);
 278         if (ret != 0) {
 279                 dev_err(dev, "Failed to disable supplies: %d\n", ret);
 280                 return ret;
 281         }
 282
 283         return 0;
 284 }
 285
 286 static int wm8994_resume(struct device *dev)
 287 {
 288         struct wm8994 *wm8994 = dev_get_drvdata(dev);
 289         int ret;
 290
 291         /* We may have lied to the PM core about suspending */
 292         if (!wm8994->suspended)
 293                 return 0;
 294
 295         ret = regulator_bulk_enable(wm8994->num_supplies,
 296                                     wm8994->supplies);
 297         if (ret != 0) {
 298                 dev_err(dev, "Failed to enable supplies: %d\n", ret);
 299                 return ret;
 300         }
 301
 302         regcache_cache_only(wm8994->regmap, false);
 303         ret = regcache_sync(wm8994->regmap);
 304         if (ret != 0) {
 305                 dev_err(dev, "Failed to restore register map: %d\n", ret);
 306                 goto err_enable;
 307         }
 308
 309         /* Disable LDO pulldowns while the device is active */
 310         wm8994_set_bits(wm8994, WM8994_PULL_CONTROL_2,
 311                         WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD,
 312                         0);
 313
 314         wm8994->suspended = false;
 315
 316         return 0;
 317
 318 err_enable:
 319         regulator_bulk_disable(wm8994->num_supplies, wm8994->supplies);
 320
 321         return ret;
 322 }
 323 #endif
 324
 325 #ifdef CONFIG_REGULATOR
 326 static int wm8994_ldo_in_use(struct wm8994_pdata *pdata, int ldo)
 327 {
 328         struct wm8994_ldo_pdata *ldo_pdata;
 329
 330         if (!pdata)
 331                 return 0;
 332
 333         ldo_pdata = &pdata->ldo[ldo];
 334
 335         if (!ldo_pdata->init_data)
 336                 return 0;
 337
 338         return ldo_pdata->init_data->num_consumer_supplies != 0;
 339 }
 340 #else
 341 static int wm8994_ldo_in_use(struct wm8994_pdata *pdata, int ldo)
 342 {
 343         return 0;
 344 }
 345 #endif
 346
 347 /*
 348  * Instantiate the generic non-control parts of the device.
 349  */
 350 static int wm8994_device_init(struct wm8994 *wm8994, int irq)
 351 {
 352         struct wm8994_pdata *pdata = wm8994->dev->platform_data;
 353         struct regmap_config *regmap_config;
 354         const char *devname;
 355         int ret, i;
 356         int pulls = 0;
 357
 358         dev_set_drvdata(wm8994->dev, wm8994);
 359
 360         /* Add the on-chip regulators first for bootstrapping */
 361         ret = mfd_add_devices(wm8994->dev, -1,
 362                               wm8994_regulator_devs,
 363                               ARRAY_SIZE(wm8994_regulator_devs),
 364                               NULL, 0);
 365         if (ret != 0) {
 366                 dev_err(wm8994->dev, "Failed to add children: %d\n", ret);
 367                 goto err_regmap;
 368         }
 369
 370         switch (wm8994->type) {
 371         case WM1811:
 372                 wm8994->num_supplies = ARRAY_SIZE(wm1811_main_supplies);
 373                 break;
 374         case WM8994:
 375                 wm8994->num_supplies = ARRAY_SIZE(wm8994_main_supplies);
 376                 break;
 377         case WM8958:
 378                 wm8994->num_supplies = ARRAY_SIZE(wm8958_main_supplies);
 379                 break;
 380         default:
 381                 BUG();
 382                 goto err_regmap;
 383         }
 384
 385         wm8994->supplies = devm_kzalloc(wm8994->dev,
 386                                         sizeof(struct regulator_bulk_data) *
 387                                         wm8994->num_supplies, GFP_KERNEL);
 388         if (!wm8994->supplies) {
 389                 ret = -ENOMEM;
 390                 goto err_regmap;
 391         }
 392
 393         switch (wm8994->type) {
 394         case WM1811:
 395                 for (i = 0; i < ARRAY_SIZE(wm1811_main_supplies); i++)
 396                         wm8994->supplies[i].supply = wm1811_main_supplies[i];
 397                 break;
 398         case WM8994:
 399                 for (i = 0; i < ARRAY_SIZE(wm8994_main_supplies); i++)
 400                         wm8994->supplies[i].supply = wm8994_main_supplies[i];
 401                 break;
 402         case WM8958:
 403                 for (i = 0; i < ARRAY_SIZE(wm8958_main_supplies); i++)
 404                         wm8994->supplies[i].supply = wm8958_main_supplies[i];
 405                 break;
 406         default:
 407                 BUG();
 408                 goto err_regmap;
 409         }
 410
 411         ret = regulator_bulk_get(wm8994->dev, wm8994->num_supplies,
 412                                  wm8994->supplies);
 413         if (ret != 0) {
 414                 dev_err(wm8994->dev, "Failed to get supplies: %d\n", ret);
 415                 goto err_regmap;
 416         }
 417
 418         ret = regulator_bulk_enable(wm8994->num_supplies,
 419                                     wm8994->supplies);
 420         if (ret != 0) {
 421                 dev_err(wm8994->dev, "Failed to enable supplies: %d\n", ret);
 422                 goto err_get;
 423         }
 424
 425         ret = wm8994_reg_read(wm8994, WM8994_SOFTWARE_RESET);
 426         if (ret < 0) {
 427                 dev_err(wm8994->dev, "Failed to read ID register\n");
 428                 goto err_enable;
 429         }
 430         switch (ret) {
 431         case 0x1811:
 432                 devname = "WM1811";
 433                 if (wm8994->type != WM1811)
 434                         dev_warn(wm8994->dev, "Device registered as type %d\n",
 435                                  wm8994->type);
 436                 wm8994->type = WM1811;
 437                 break;
 438         case 0x8994:
 439                 devname = "WM8994";
 440                 if (wm8994->type != WM8994)
 441                         dev_warn(wm8994->dev, "Device registered as type %d\n",
 442                                  wm8994->type);
 443                 wm8994->type = WM8994;
 444                 break;
 445         case 0x8958:
 446                 devname = "WM8958";
 447                 if (wm8994->type != WM8958)
 448                         dev_warn(wm8994->dev, "Device registered as type %d\n",
 449                                  wm8994->type);
 450                 wm8994->type = WM8958;
 451                 break;
 452         default:
 453                 dev_err(wm8994->dev, "Device is not a WM8994, ID is %x\n",
 454                         ret);
 455                 ret = -EINVAL;
 456                 goto err_enable;
 457         }
 458
 459         ret = wm8994_reg_read(wm8994, WM8994_CHIP_REVISION);
 460         if (ret < 0) {
 461                 dev_err(wm8994->dev, "Failed to read revision register: %d\n",
 462                         ret);
 463                 goto err_enable;
 464         }
 465         wm8994->revision = ret;
 466
 467         switch (wm8994->type) {
 468         case WM8994:
 469                 switch (wm8994->revision) {
 470                 case 0:
 471                 case 1:
 472                         dev_warn(wm8994->dev,
 473                                  "revision %c not fully supported\n",
 474                                  'A' + wm8994->revision);
 475                         break;
 476                 default:
 477                         break;
 478                 }
 479                 break;
 480         case WM1811:
 481                 /* Revision C did not change the relevant layer */
 482                 if (wm8994->revision > 1)
 483                         wm8994->revision++;
 484                 break;
 485         default:
 486                 break;
 487         }
 488
 489         dev_info(wm8994->dev, "%s revision %c\n", devname,
 490                  'A' + wm8994->revision);
 491
 492         switch (wm8994->type) {
 493         case WM1811:
 494                 regmap_config = &wm1811_regmap_config;
 495                 break;
 496         case WM8994:
 497                 regmap_config = &wm8994_regmap_config;
 498                 break;
 499         case WM8958:
 500                 regmap_config = &wm8958_regmap_config;
 501                 break;
 502         default:
 503                 dev_err(wm8994->dev, "Unknown device type %d\n", wm8994->type);
 504                 return -EINVAL;
 505         }
 506
 507         ret = regmap_reinit_cache(wm8994->regmap, regmap_config);
 508         if (ret != 0) {
 509                 dev_err(wm8994->dev, "Failed to reinit register cache: %d\n",
 510                         ret);
 511                 return ret;
 512         }
 513
 514         if (pdata) {
 515                 wm8994->irq_base = pdata->irq_base;
 516                 wm8994->gpio_base = pdata->gpio_base;
 517
 518                 /* GPIO configuration is only applied if it's non-zero */
 519                 for (i = 0; i < ARRAY_SIZE(pdata->gpio_defaults); i++) {
 520                         if (pdata->gpio_defaults[i]) {
 521                                 wm8994_set_bits(wm8994, WM8994_GPIO_1 + i,
 522                                                 0xffff,
 523                                                 pdata->gpio_defaults[i]);
 524                         }
 525                 }
 526
 527                 wm8994->ldo_ena_always_driven = pdata->ldo_ena_always_driven;
 528
 529                 if (pdata->spkmode_pu)
 530                         pulls |= WM8994_SPKMODE_PU;
 531         }
 532
 533         /* Disable unneeded pulls */
 534         wm8994_set_bits(wm8994, WM8994_PULL_CONTROL_2,
 535                         WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD |
 536                         WM8994_SPKMODE_PU | WM8994_CSNADDR_PD,
 537                         pulls);
 538
 539         /* In some system designs where the regulators are not in use,
 540          * we can achieve a small reduction in leakage currents by
 541          * floating LDO outputs.  This bit makes no difference if the
 542          * LDOs are enabled, it only affects cases where the LDOs were
 543          * in operation and are then disabled.
 544          */
 545         for (i = 0; i < WM8994_NUM_LDO_REGS; i++) {
 546                 if (wm8994_ldo_in_use(pdata, i))
 547                         wm8994_set_bits(wm8994, WM8994_LDO_1 + i,
 548                                         WM8994_LDO1_DISCH, WM8994_LDO1_DISCH);
 549                 else
 550                         wm8994_set_bits(wm8994, WM8994_LDO_1 + i,
 551                                         WM8994_LDO1_DISCH, 0);
 552         }
 553
 554         wm8994_irq_init(wm8994);
 555
 556         ret = mfd_add_devices(wm8994->dev, -1,
 557                               wm8994_devs, ARRAY_SIZE(wm8994_devs),
 558                               NULL, 0);
 559         if (ret != 0) {
 560                 dev_err(wm8994->dev, "Failed to add children: %d\n", ret);
 561                 goto err_irq;
 562         }
 563
 564         pm_runtime_enable(wm8994->dev);
 565         pm_runtime_resume(wm8994->dev);
 566
 567         return 0;
 568
 569 err_irq:
 570         wm8994_irq_exit(wm8994);
 571 err_enable:
 572         regulator_bulk_disable(wm8994->num_supplies,
 573                                wm8994->supplies);
 574 err_get:
 575         regulator_bulk_free(wm8994->num_supplies, wm8994->supplies);
 576 err_regmap:
 577         regmap_exit(wm8994->regmap);
 578         mfd_remove_devices(wm8994->dev);
 579         return ret;
 580 }
 581
 582 static void wm8994_device_exit(struct wm8994 *wm8994)
 583 {
 584         pm_runtime_disable(wm8994->dev);
 585         mfd_remove_devices(wm8994->dev);
 586         wm8994_irq_exit(wm8994);
 587         regulator_bulk_disable(wm8994->num_supplies,
 588                                wm8994->supplies);
 589         regulator_bulk_free(wm8994->num_supplies, wm8994->supplies);
 590         regmap_exit(wm8994->regmap);
 591 }
 592
 593 static const struct of_device_id wm8994_of_match[] = {
 594         { .compatible = "wlf,wm1811", },
 595         { .compatible = "wlf,wm8994", },
 596         { .compatible = "wlf,wm8958", },
 597         { }
 598 };
 599 MODULE_DEVICE_TABLE(of, wm8994_of_match);
 600
 601 static int wm8994_i2c_probe(struct i2c_client *i2c,
 602                             const struct i2c_device_id *id)
 603 {
 604         struct wm8994 *wm8994;
 605         int ret;
 606
 607         wm8994 = devm_kzalloc(&i2c->dev, sizeof(struct wm8994), GFP_KERNEL);
 608         if (wm8994 == NULL)
 609                 return -ENOMEM;
 610
 611         i2c_set_clientdata(i2c, wm8994);
 612         wm8994->dev = &i2c->dev;
 613         wm8994->irq = i2c->irq;
 614         wm8994->type = id->driver_data;
 615
 616         wm8994->regmap = regmap_init_i2c(i2c, &wm8994_base_regmap_config);
 617         if (IS_ERR(wm8994->regmap)) {
 618                 ret = PTR_ERR(wm8994->regmap);
 619                 dev_err(wm8994->dev, "Failed to allocate register map: %d\n",
 620                         ret);
 621                 return ret;
 622         }
 623
 624         return wm8994_device_init(wm8994, i2c->irq);
 625 }
 626
 627 static int wm8994_i2c_remove(struct i2c_client *i2c)
 628 {
 629         struct wm8994 *wm8994 = i2c_get_clientdata(i2c);
 630
 631         wm8994_device_exit(wm8994);
 632
 633         return 0;
 634 }
 635
 636 static const struct i2c_device_id wm8994_i2c_id[] = {
 637         { "wm1811", WM1811 },
 638         { "wm1811a", WM1811 },
 639         { "wm8994", WM8994 },
 640         { "wm8958", WM8958 },
 641         { }
 642 };
 643 MODULE_DEVICE_TABLE(i2c, wm8994_i2c_id);
 644
 645 static UNIVERSAL_DEV_PM_OPS(wm8994_pm_ops, wm8994_suspend, wm8994_resume,
 646                             NULL);
 647
 648 static struct i2c_driver wm8994_i2c_driver = {
 649         .driver = {
 650                 .name = "wm8994",
 651                 .owner = THIS_MODULE,
 652                 .pm = &wm8994_pm_ops,
 653                 .of_match_table = wm8994_of_match,
 654         },
 655         .probe = wm8994_i2c_probe,
 656         .remove = wm8994_i2c_remove,
 657         .id_table = wm8994_i2c_id,
 658 };
 659
 660 static int __init wm8994_i2c_init(void)
 661 {
 662         int ret;
 663
 664         ret = i2c_add_driver(&wm8994_i2c_driver);
 665         if (ret != 0)
 666                 pr_err("Failed to register wm8994 I2C driver: %d\n", ret);
 667
 668         return ret;
 669 }
 670 module_init(wm8994_i2c_init);
 671
 672 static void __exit wm8994_i2c_exit(void)
 673 {
 674         i2c_del_driver(&wm8994_i2c_driver);
 675 }
 676 module_exit(wm8994_i2c_exit);
 677
 678 MODULE_DESCRIPTION("Core support for the WM8994 audio CODEC");
 679 MODULE_LICENSE("GPL");
 680 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");