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         case WM1811:
 233                 ret = wm8994_reg_read(wm8994, WM8958_MIC_DETECT_1);
 234                 if (ret < 0) {
 235                         dev_err(dev, "Failed to read power status: %d\n", ret);
 236                 } else if (ret & WM8958_MICD_ENA) {
 237                         dev_dbg(dev, "CODEC still active, ignoring suspend\n");
 238                         return 0;
 239                 }
 240                 break;
 241         default:
 242                 break;
 243         }
 244
 245         switch (wm8994->type) {
 246         case WM1811:
 247                 ret = wm8994_reg_read(wm8994, WM8994_ANTIPOP_2);
 248                 if (ret < 0) {
 249                         dev_err(dev, "Failed to read jackdet: %d\n", ret);
 250                 } else if (ret & WM1811_JACKDET_MODE_MASK) {
 251                         dev_dbg(dev, "CODEC still active, ignoring suspend\n");
 252                         return 0;
 253                 }
 254                 break;
 255         default:
 256                 break;
 257         }
 258
 259         /* Disable LDO pulldowns while the device is suspended if we
 260          * don't know that something will be driving them. */
 261         if (!wm8994->ldo_ena_always_driven)
 262                 wm8994_set_bits(wm8994, WM8994_PULL_CONTROL_2,
 263                                 WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD,
 264                                 WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD);
 265
 266         /* Explicitly put the device into reset in case regulators
 267          * don't get disabled in order to ensure consistent restart.
 268          */
 269         wm8994_reg_write(wm8994, WM8994_SOFTWARE_RESET,
 270                          wm8994_reg_read(wm8994, WM8994_SOFTWARE_RESET));
 271
 272         regcache_cache_only(wm8994->regmap, true);
 273         regcache_mark_dirty(wm8994->regmap);
 274
 275         wm8994->suspended = true;
 276
 277         ret = regulator_bulk_disable(wm8994->num_supplies,
 278                                      wm8994->supplies);
 279         if (ret != 0) {
 280                 dev_err(dev, "Failed to disable supplies: %d\n", ret);
 281                 return ret;
 282         }
 283
 284         return 0;
 285 }
 286
 287 static int wm8994_resume(struct device *dev)
 288 {
 289         struct wm8994 *wm8994 = dev_get_drvdata(dev);
 290         int ret;
 291
 292         /* We may have lied to the PM core about suspending */
 293         if (!wm8994->suspended)
 294                 return 0;
 295
 296         ret = regulator_bulk_enable(wm8994->num_supplies,
 297                                     wm8994->supplies);
 298         if (ret != 0) {
 299                 dev_err(dev, "Failed to enable supplies: %d\n", ret);
 300                 return ret;
 301         }
 302
 303         regcache_cache_only(wm8994->regmap, false);
 304         ret = regcache_sync(wm8994->regmap);
 305         if (ret != 0) {
 306                 dev_err(dev, "Failed to restore register map: %d\n", ret);
 307                 goto err_enable;
 308         }
 309
 310         /* Disable LDO pulldowns while the device is active */
 311         wm8994_set_bits(wm8994, WM8994_PULL_CONTROL_2,
 312                         WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD,
 313                         0);
 314
 315         wm8994->suspended = false;
 316
 317         return 0;
 318
 319 err_enable:
 320         regulator_bulk_disable(wm8994->num_supplies, wm8994->supplies);
 321
 322         return ret;
 323 }
 324 #endif
 325
 326 #ifdef CONFIG_REGULATOR
 327 static int wm8994_ldo_in_use(struct wm8994_pdata *pdata, int ldo)
 328 {
 329         struct wm8994_ldo_pdata *ldo_pdata;
 330
 331         if (!pdata)
 332                 return 0;
 333
 334         ldo_pdata = &pdata->ldo[ldo];
 335
 336         if (!ldo_pdata->init_data)
 337                 return 0;
 338
 339         return ldo_pdata->init_data->num_consumer_supplies != 0;
 340 }
 341 #else
 342 static int wm8994_ldo_in_use(struct wm8994_pdata *pdata, int ldo)
 343 {
 344         return 0;
 345 }
 346 #endif
 347
 348 /*
 349  * Instantiate the generic non-control parts of the device.
 350  */
 351 static int wm8994_device_init(struct wm8994 *wm8994, int irq)
 352 {
 353         struct wm8994_pdata *pdata = wm8994->dev->platform_data;
 354         struct regmap_config *regmap_config;
 355         const char *devname;
 356         int ret, i;
 357         int pulls = 0;
 358
 359         dev_set_drvdata(wm8994->dev, wm8994);
 360
 361         /* Add the on-chip regulators first for bootstrapping */
 362         ret = mfd_add_devices(wm8994->dev, -1,
 363                               wm8994_regulator_devs,
 364                               ARRAY_SIZE(wm8994_regulator_devs),
 365                               NULL, 0);
 366         if (ret != 0) {
 367                 dev_err(wm8994->dev, "Failed to add children: %d\n", ret);
 368                 goto err_regmap;
 369         }
 370
 371         switch (wm8994->type) {
 372         case WM1811:
 373                 wm8994->num_supplies = ARRAY_SIZE(wm1811_main_supplies);
 374                 break;
 375         case WM8994:
 376                 wm8994->num_supplies = ARRAY_SIZE(wm8994_main_supplies);
 377                 break;
 378         case WM8958:
 379                 wm8994->num_supplies = ARRAY_SIZE(wm8958_main_supplies);
 380                 break;
 381         default:
 382                 BUG();
 383                 goto err_regmap;
 384         }
 385
 386         wm8994->supplies = devm_kzalloc(wm8994->dev,
 387                                         sizeof(struct regulator_bulk_data) *
 388                                         wm8994->num_supplies, GFP_KERNEL);
 389         if (!wm8994->supplies) {
 390                 ret = -ENOMEM;
 391                 goto err_regmap;
 392         }
 393
 394         switch (wm8994->type) {
 395         case WM1811:
 396                 for (i = 0; i < ARRAY_SIZE(wm1811_main_supplies); i++)
 397                         wm8994->supplies[i].supply = wm1811_main_supplies[i];
 398                 break;
 399         case WM8994:
 400                 for (i = 0; i < ARRAY_SIZE(wm8994_main_supplies); i++)
 401                         wm8994->supplies[i].supply = wm8994_main_supplies[i];
 402                 break;
 403         case WM8958:
 404                 for (i = 0; i < ARRAY_SIZE(wm8958_main_supplies); i++)
 405                         wm8994->supplies[i].supply = wm8958_main_supplies[i];
 406                 break;
 407         default:
 408                 BUG();
 409                 goto err_regmap;
 410         }
 411
 412         ret = regulator_bulk_get(wm8994->dev, wm8994->num_supplies,
 413                                  wm8994->supplies);
 414         if (ret != 0) {
 415                 dev_err(wm8994->dev, "Failed to get supplies: %d\n", ret);
 416                 goto err_regmap;
 417         }
 418
 419         ret = regulator_bulk_enable(wm8994->num_supplies,
 420                                     wm8994->supplies);
 421         if (ret != 0) {
 422                 dev_err(wm8994->dev, "Failed to enable supplies: %d\n", ret);
 423                 goto err_get;
 424         }
 425
 426         ret = wm8994_reg_read(wm8994, WM8994_SOFTWARE_RESET);
 427         if (ret < 0) {
 428                 dev_err(wm8994->dev, "Failed to read ID register\n");
 429                 goto err_enable;
 430         }
 431         switch (ret) {
 432         case 0x1811:
 433                 devname = "WM1811";
 434                 if (wm8994->type != WM1811)
 435                         dev_warn(wm8994->dev, "Device registered as type %d\n",
 436                                  wm8994->type);
 437                 wm8994->type = WM1811;
 438                 break;
 439         case 0x8994:
 440                 devname = "WM8994";
 441                 if (wm8994->type != WM8994)
 442                         dev_warn(wm8994->dev, "Device registered as type %d\n",
 443                                  wm8994->type);
 444                 wm8994->type = WM8994;
 445                 break;
 446         case 0x8958:
 447                 devname = "WM8958";
 448                 if (wm8994->type != WM8958)
 449                         dev_warn(wm8994->dev, "Device registered as type %d\n",
 450                                  wm8994->type);
 451                 wm8994->type = WM8958;
 452                 break;
 453         default:
 454                 dev_err(wm8994->dev, "Device is not a WM8994, ID is %x\n",
 455                         ret);
 456                 ret = -EINVAL;
 457                 goto err_enable;
 458         }
 459
 460         ret = wm8994_reg_read(wm8994, WM8994_CHIP_REVISION);
 461         if (ret < 0) {
 462                 dev_err(wm8994->dev, "Failed to read revision register: %d\n",
 463                         ret);
 464                 goto err_enable;
 465         }
 466         wm8994->revision = ret;
 467
 468         switch (wm8994->type) {
 469         case WM8994:
 470                 switch (wm8994->revision) {
 471                 case 0:
 472                 case 1:
 473                         dev_warn(wm8994->dev,
 474                                  "revision %c not fully supported\n",
 475                                  'A' + wm8994->revision);
 476                         break;
 477                 default:
 478                         break;
 479                 }
 480                 break;
 481         case WM1811:
 482                 /* Revision C did not change the relevant layer */
 483                 if (wm8994->revision > 1)
 484                         wm8994->revision++;
 485                 break;
 486         default:
 487                 break;
 488         }
 489
 490         dev_info(wm8994->dev, "%s revision %c\n", devname,
 491                  'A' + wm8994->revision);
 492
 493         switch (wm8994->type) {
 494         case WM1811:
 495                 regmap_config = &wm1811_regmap_config;
 496                 break;
 497         case WM8994:
 498                 regmap_config = &wm8994_regmap_config;
 499                 break;
 500         case WM8958:
 501                 regmap_config = &wm8958_regmap_config;
 502                 break;
 503         default:
 504                 dev_err(wm8994->dev, "Unknown device type %d\n", wm8994->type);
 505                 return -EINVAL;
 506         }
 507
 508         ret = regmap_reinit_cache(wm8994->regmap, regmap_config);
 509         if (ret != 0) {
 510                 dev_err(wm8994->dev, "Failed to reinit register cache: %d\n",
 511                         ret);
 512                 return ret;
 513         }
 514
 515         if (pdata) {
 516                 wm8994->irq_base = pdata->irq_base;
 517                 wm8994->gpio_base = pdata->gpio_base;
 518
 519                 /* GPIO configuration is only applied if it's non-zero */
 520                 for (i = 0; i < ARRAY_SIZE(pdata->gpio_defaults); i++) {
 521                         if (pdata->gpio_defaults[i]) {
 522                                 wm8994_set_bits(wm8994, WM8994_GPIO_1 + i,
 523                                                 0xffff,
 524                                                 pdata->gpio_defaults[i]);
 525                         }
 526                 }
 527
 528                 wm8994->ldo_ena_always_driven = pdata->ldo_ena_always_driven;
 529
 530                 if (pdata->spkmode_pu)
 531                         pulls |= WM8994_SPKMODE_PU;
 532         }
 533
 534         /* Disable unneeded pulls */
 535         wm8994_set_bits(wm8994, WM8994_PULL_CONTROL_2,
 536                         WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD |
 537                         WM8994_SPKMODE_PU | WM8994_CSNADDR_PD,
 538                         pulls);
 539
 540         /* In some system designs where the regulators are not in use,
 541          * we can achieve a small reduction in leakage currents by
 542          * floating LDO outputs.  This bit makes no difference if the
 543          * LDOs are enabled, it only affects cases where the LDOs were
 544          * in operation and are then disabled.
 545          */
 546         for (i = 0; i < WM8994_NUM_LDO_REGS; i++) {
 547                 if (wm8994_ldo_in_use(pdata, i))
 548                         wm8994_set_bits(wm8994, WM8994_LDO_1 + i,
 549                                         WM8994_LDO1_DISCH, WM8994_LDO1_DISCH);
 550                 else
 551                         wm8994_set_bits(wm8994, WM8994_LDO_1 + i,
 552                                         WM8994_LDO1_DISCH, 0);
 553         }
 554
 555         wm8994_irq_init(wm8994);
 556
 557         ret = mfd_add_devices(wm8994->dev, -1,
 558                               wm8994_devs, ARRAY_SIZE(wm8994_devs),
 559                               NULL, 0);
 560         if (ret != 0) {
 561                 dev_err(wm8994->dev, "Failed to add children: %d\n", ret);
 562                 goto err_irq;
 563         }
 564
 565         pm_runtime_enable(wm8994->dev);
 566         pm_runtime_resume(wm8994->dev);
 567
 568         return 0;
 569
 570 err_irq:
 571         wm8994_irq_exit(wm8994);
 572 err_enable:
 573         regulator_bulk_disable(wm8994->num_supplies,
 574                                wm8994->supplies);
 575 err_get:
 576         regulator_bulk_free(wm8994->num_supplies, wm8994->supplies);
 577 err_regmap:
 578         regmap_exit(wm8994->regmap);
 579         mfd_remove_devices(wm8994->dev);
 580         return ret;
 581 }
 582
 583 static void wm8994_device_exit(struct wm8994 *wm8994)
 584 {
 585         pm_runtime_disable(wm8994->dev);
 586         mfd_remove_devices(wm8994->dev);
 587         wm8994_irq_exit(wm8994);
 588         regulator_bulk_disable(wm8994->num_supplies,
 589                                wm8994->supplies);
 590         regulator_bulk_free(wm8994->num_supplies, wm8994->supplies);
 591         regmap_exit(wm8994->regmap);
 592 }
 593
 594 static const struct of_device_id wm8994_of_match[] = {
 595         { .compatible = "wlf,wm1811", },
 596         { .compatible = "wlf,wm8994", },
 597         { .compatible = "wlf,wm8958", },
 598         { }
 599 };
 600 MODULE_DEVICE_TABLE(of, wm8994_of_match);
 601
 602 static int wm8994_i2c_probe(struct i2c_client *i2c,
 603                             const struct i2c_device_id *id)
 604 {
 605         struct wm8994 *wm8994;
 606         int ret;
 607
 608         wm8994 = devm_kzalloc(&i2c->dev, sizeof(struct wm8994), GFP_KERNEL);
 609         if (wm8994 == NULL)
 610                 return -ENOMEM;
 611
 612         i2c_set_clientdata(i2c, wm8994);
 613         wm8994->dev = &i2c->dev;
 614         wm8994->irq = i2c->irq;
 615         wm8994->type = id->driver_data;
 616
 617         wm8994->regmap = regmap_init_i2c(i2c, &wm8994_base_regmap_config);
 618         if (IS_ERR(wm8994->regmap)) {
 619                 ret = PTR_ERR(wm8994->regmap);
 620                 dev_err(wm8994->dev, "Failed to allocate register map: %d\n",
 621                         ret);
 622                 return ret;
 623         }
 624
 625         return wm8994_device_init(wm8994, i2c->irq);
 626 }
 627
 628 static int wm8994_i2c_remove(struct i2c_client *i2c)
 629 {
 630         struct wm8994 *wm8994 = i2c_get_clientdata(i2c);
 631
 632         wm8994_device_exit(wm8994);
 633
 634         return 0;
 635 }
 636
 637 static const struct i2c_device_id wm8994_i2c_id[] = {
 638         { "wm1811", WM1811 },
 639         { "wm1811a", WM1811 },
 640         { "wm8994", WM8994 },
 641         { "wm8958", WM8958 },
 642         { }
 643 };
 644 MODULE_DEVICE_TABLE(i2c, wm8994_i2c_id);
 645
 646 static UNIVERSAL_DEV_PM_OPS(wm8994_pm_ops, wm8994_suspend, wm8994_resume,
 647                             NULL);
 648
 649 static struct i2c_driver wm8994_i2c_driver = {
 650         .driver = {
 651                 .name = "wm8994",
 652                 .owner = THIS_MODULE,
 653                 .pm = &wm8994_pm_ops,
 654                 .of_match_table = wm8994_of_match,
 655         },
 656         .probe = wm8994_i2c_probe,
 657         .remove = wm8994_i2c_remove,
 658         .id_table = wm8994_i2c_id,
 659 };
 660
 661 static int __init wm8994_i2c_init(void)
 662 {
 663         int ret;
 664
 665         ret = i2c_add_driver(&wm8994_i2c_driver);
 666         if (ret != 0)
 667                 pr_err("Failed to register wm8994 I2C driver: %d\n", ret);
 668
 669         return ret;
 670 }
 671 module_init(wm8994_i2c_init);
 672
 673 static void __exit wm8994_i2c_exit(void)
 674 {
 675         i2c_del_driver(&wm8994_i2c_driver);
 676 }
 677 module_exit(wm8994_i2c_exit);
 678
 679 MODULE_DESCRIPTION("Core support for the WM8994 audio CODEC");
 680 MODULE_LICENSE("GPL");
 681 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");