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 static int wm8994_read(struct wm8994 *wm8994, unsigned short reg,
  32                        int bytes, void *dest)
  33 {
  34         return regmap_raw_read(wm8994->regmap, reg, dest, bytes);
  35 }
  36
  37 /**
  38  * wm8994_reg_read: Read a single WM8994 register.
  39  *
  40  * @wm8994: Device to read from.
  41  * @reg: Register to read.
  42  */
  43 int wm8994_reg_read(struct wm8994 *wm8994, unsigned short reg)
  44 {
  45         unsigned int val;
  46         int ret;
  47
  48         ret = regmap_read(wm8994->regmap, reg, &val);
  49
  50         if (ret < 0)
  51                 return ret;
  52         else
  53                 return val;
  54 }
  55 EXPORT_SYMBOL_GPL(wm8994_reg_read);
  56
  57 /**
  58  * wm8994_bulk_read: Read multiple WM8994 registers
  59  *
  60  * @wm8994: Device to read from
  61  * @reg: First register
  62  * @count: Number of registers
  63  * @buf: Buffer to fill.  The data will be returned big endian.
  64  */
  65 int wm8994_bulk_read(struct wm8994 *wm8994, unsigned short reg,
  66                      int count, u16 *buf)
  67 {
  68         return regmap_bulk_read(wm8994->regmap, reg, buf, count);
  69 }
  70
  71 static int wm8994_write(struct wm8994 *wm8994, unsigned short reg,
  72                         int bytes, const void *src)
  73 {
  74         return regmap_raw_write(wm8994->regmap, reg, src, bytes);
  75 }
  76
  77 /**
  78  * wm8994_reg_write: Write a single WM8994 register.
  79  *
  80  * @wm8994: Device to write to.
  81  * @reg: Register to write to.
  82  * @val: Value to write.
  83  */
  84 int wm8994_reg_write(struct wm8994 *wm8994, unsigned short reg,
  85                      unsigned short val)
  86 {
  87         return regmap_write(wm8994->regmap, reg, val);
  88 }
  89 EXPORT_SYMBOL_GPL(wm8994_reg_write);
  90
  91 /**
  92  * wm8994_bulk_write: Write multiple WM8994 registers
  93  *
  94  * @wm8994: Device to write to
  95  * @reg: First register
  96  * @count: Number of registers
  97  * @buf: Buffer to write from.  Data must be big-endian formatted.
  98  */
  99 int wm8994_bulk_write(struct wm8994 *wm8994, unsigned short reg,
 100                       int count, const u16 *buf)
 101 {
 102         return regmap_raw_write(wm8994->regmap, reg, buf, count * sizeof(u16));
 103 }
 104 EXPORT_SYMBOL_GPL(wm8994_bulk_write);
 105
 106 /**
 107  * wm8994_set_bits: Set the value of a bitfield in a WM8994 register
 108  *
 109  * @wm8994: Device to write to.
 110  * @reg: Register to write to.
 111  * @mask: Mask of bits to set.
 112  * @val: Value to set (unshifted)
 113  */
 114 int wm8994_set_bits(struct wm8994 *wm8994, unsigned short reg,
 115                     unsigned short mask, unsigned short val)
 116 {
 117         return regmap_update_bits(wm8994->regmap, reg, mask, val);
 118 }
 119 EXPORT_SYMBOL_GPL(wm8994_set_bits);
 120
 121 static struct mfd_cell wm8994_regulator_devs[] = {
 122         {
 123                 .name = "wm8994-ldo",
 124                 .id = 1,
 125                 .pm_runtime_no_callbacks = true,
 126         },
 127         {
 128                 .name = "wm8994-ldo",
 129                 .id = 2,
 130                 .pm_runtime_no_callbacks = true,
 131         },
 132 };
 133
 134 static struct resource wm8994_codec_resources[] = {
 135         {
 136                 .start = WM8994_IRQ_TEMP_SHUT,
 137                 .end   = WM8994_IRQ_TEMP_WARN,
 138                 .flags = IORESOURCE_IRQ,
 139         },
 140 };
 141
 142 static struct resource wm8994_gpio_resources[] = {
 143         {
 144                 .start = WM8994_IRQ_GPIO(1),
 145                 .end   = WM8994_IRQ_GPIO(11),
 146                 .flags = IORESOURCE_IRQ,
 147         },
 148 };
 149
 150 static struct mfd_cell wm8994_devs[] = {
 151         {
 152                 .name = "wm8994-codec",
 153                 .num_resources = ARRAY_SIZE(wm8994_codec_resources),
 154                 .resources = wm8994_codec_resources,
 155         },
 156
 157         {
 158                 .name = "wm8994-gpio",
 159                 .num_resources = ARRAY_SIZE(wm8994_gpio_resources),
 160                 .resources = wm8994_gpio_resources,
 161                 .pm_runtime_no_callbacks = true,
 162         },
 163 };
 164
 165 /*
 166  * Supplies for the main bulk of CODEC; the LDO supplies are ignored
 167  * and should be handled via the standard regulator API supply
 168  * management.
 169  */
 170 static const char *wm1811_main_supplies[] = {
 171         "DBVDD1",
 172         "DBVDD2",
 173         "DBVDD3",
 174         "DCVDD",
 175         "AVDD1",
 176         "AVDD2",
 177         "CPVDD",
 178         "SPKVDD1",
 179         "SPKVDD2",
 180 };
 181
 182 static const char *wm8994_main_supplies[] = {
 183         "DBVDD",
 184         "DCVDD",
 185         "AVDD1",
 186         "AVDD2",
 187         "CPVDD",
 188         "SPKVDD1",
 189         "SPKVDD2",
 190 };
 191
 192 static const char *wm8958_main_supplies[] = {
 193         "DBVDD1",
 194         "DBVDD2",
 195         "DBVDD3",
 196         "DCVDD",
 197         "AVDD1",
 198         "AVDD2",
 199         "CPVDD",
 200         "SPKVDD1",
 201         "SPKVDD2",
 202 };
 203
 204 #ifdef CONFIG_PM
 205 static int wm8994_suspend(struct device *dev)
 206 {
 207         struct wm8994 *wm8994 = dev_get_drvdata(dev);
 208         int ret;
 209
 210         /* Don't actually go through with the suspend if the CODEC is
 211          * still active (eg, for audio passthrough from CP. */
 212         ret = wm8994_reg_read(wm8994, WM8994_POWER_MANAGEMENT_1);
 213         if (ret < 0) {
 214                 dev_err(dev, "Failed to read power status: %d\n", ret);
 215         } else if (ret & WM8994_VMID_SEL_MASK) {
 216                 dev_dbg(dev, "CODEC still active, ignoring suspend\n");
 217                 return 0;
 218         }
 219
 220         ret = wm8994_reg_read(wm8994, WM8994_POWER_MANAGEMENT_4);
 221         if (ret < 0) {
 222                 dev_err(dev, "Failed to read power status: %d\n", ret);
 223         } else if (ret & (WM8994_AIF2ADCL_ENA | WM8994_AIF2ADCR_ENA |
 224                           WM8994_AIF1ADC2L_ENA | WM8994_AIF1ADC2R_ENA |
 225                           WM8994_AIF1ADC1L_ENA | WM8994_AIF1ADC1R_ENA)) {
 226                 dev_dbg(dev, "CODEC still active, ignoring suspend\n");
 227                 return 0;
 228         }
 229
 230         ret = wm8994_reg_read(wm8994, WM8994_POWER_MANAGEMENT_5);
 231         if (ret < 0) {
 232                 dev_err(dev, "Failed to read power status: %d\n", ret);
 233         } else if (ret & (WM8994_AIF2DACL_ENA | WM8994_AIF2DACR_ENA |
 234                           WM8994_AIF1DAC2L_ENA | WM8994_AIF1DAC2R_ENA |
 235                           WM8994_AIF1DAC1L_ENA | WM8994_AIF1DAC1R_ENA)) {
 236                 dev_dbg(dev, "CODEC still active, ignoring suspend\n");
 237                 return 0;
 238         }
 239
 240         switch (wm8994->type) {
 241         case WM8958:
 242                 ret = wm8994_reg_read(wm8994, WM8958_MIC_DETECT_1);
 243                 if (ret < 0) {
 244                         dev_err(dev, "Failed to read power status: %d\n", ret);
 245                 } else if (ret & WM8958_MICD_ENA) {
 246                         dev_dbg(dev, "CODEC still active, ignoring suspend\n");
 247                         return 0;
 248                 }
 249                 break;
 250         default:
 251                 break;
 252         }
 253
 254         /* Disable LDO pulldowns while the device is suspended if we
 255          * don't know that something will be driving them. */
 256         if (!wm8994->ldo_ena_always_driven)
 257                 wm8994_set_bits(wm8994, WM8994_PULL_CONTROL_2,
 258                                 WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD,
 259                                 WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD);
 260
 261         /* GPIO configuration state is saved here since we may be configuring
 262          * the GPIO alternate functions even if we're not using the gpiolib
 263          * driver for them.
 264          */
 265         ret = wm8994_read(wm8994, WM8994_GPIO_1, WM8994_NUM_GPIO_REGS * 2,
 266                           &wm8994->gpio_regs);
 267         if (ret < 0)
 268                 dev_err(dev, "Failed to save GPIO registers: %d\n", ret);
 269
 270         /* For similar reasons we also stash the regulator states */
 271         ret = wm8994_read(wm8994, WM8994_LDO_1, WM8994_NUM_LDO_REGS * 2,
 272                           &wm8994->ldo_regs);
 273         if (ret < 0)
 274                 dev_err(dev, "Failed to save LDO registers: %d\n", ret);
 275
 276         /* Explicitly put the device into reset in case regulators
 277          * don't get disabled in order to ensure consistent restart.
 278          */
 279         wm8994_reg_write(wm8994, WM8994_SOFTWARE_RESET, 0x8994);
 280
 281         wm8994->suspended = true;
 282
 283         ret = regulator_bulk_disable(wm8994->num_supplies,
 284                                      wm8994->supplies);
 285         if (ret != 0) {
 286                 dev_err(dev, "Failed to disable supplies: %d\n", ret);
 287                 return ret;
 288         }
 289
 290         return 0;
 291 }
 292
 293 static int wm8994_resume(struct device *dev)
 294 {
 295         struct wm8994 *wm8994 = dev_get_drvdata(dev);
 296         int ret, i;
 297
 298         /* We may have lied to the PM core about suspending */
 299         if (!wm8994->suspended)
 300                 return 0;
 301
 302         ret = regulator_bulk_enable(wm8994->num_supplies,
 303                                     wm8994->supplies);
 304         if (ret != 0) {
 305                 dev_err(dev, "Failed to enable supplies: %d\n", ret);
 306                 return ret;
 307         }
 308
 309         /* Write register at a time as we use the cache on the CPU so store
 310          * it in native endian.
 311          */
 312         for (i = 0; i < ARRAY_SIZE(wm8994->irq_masks_cur); i++) {
 313                 ret = wm8994_reg_write(wm8994, WM8994_INTERRUPT_STATUS_1_MASK
 314                                        + i, wm8994->irq_masks_cur[i]);
 315                 if (ret < 0)
 316                         dev_err(dev, "Failed to restore interrupt masks: %d\n",
 317                                 ret);
 318         }
 319
 320         ret = wm8994_write(wm8994, WM8994_LDO_1, WM8994_NUM_LDO_REGS * 2,
 321                            &wm8994->ldo_regs);
 322         if (ret < 0)
 323                 dev_err(dev, "Failed to restore LDO registers: %d\n", ret);
 324
 325         ret = wm8994_write(wm8994, WM8994_GPIO_1, WM8994_NUM_GPIO_REGS * 2,
 326                            &wm8994->gpio_regs);
 327         if (ret < 0)
 328                 dev_err(dev, "Failed to restore GPIO registers: %d\n", ret);
 329
 330         /* Disable LDO pulldowns while the device is active */
 331         wm8994_set_bits(wm8994, WM8994_PULL_CONTROL_2,
 332                         WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD,
 333                         0);
 334
 335         wm8994->suspended = false;
 336
 337         return 0;
 338 }
 339 #endif
 340
 341 #ifdef CONFIG_REGULATOR
 342 static int wm8994_ldo_in_use(struct wm8994_pdata *pdata, int ldo)
 343 {
 344         struct wm8994_ldo_pdata *ldo_pdata;
 345
 346         if (!pdata)
 347                 return 0;
 348
 349         ldo_pdata = &pdata->ldo[ldo];
 350
 351         if (!ldo_pdata->init_data)
 352                 return 0;
 353
 354         return ldo_pdata->init_data->num_consumer_supplies != 0;
 355 }
 356 #else
 357 static int wm8994_ldo_in_use(struct wm8994_pdata *pdata, int ldo)
 358 {
 359         return 0;
 360 }
 361 #endif
 362
 363 static struct regmap_config wm8994_regmap_config = {
 364         .reg_bits = 16,
 365         .val_bits = 16,
 366 };
 367
 368 /*
 369  * Instantiate the generic non-control parts of the device.
 370  */
 371 static int wm8994_device_init(struct wm8994 *wm8994, int irq)
 372 {
 373         struct wm8994_pdata *pdata = wm8994->dev->platform_data;
 374         const char *devname;
 375         int ret, i;
 376
 377         dev_set_drvdata(wm8994->dev, wm8994);
 378
 379         /* Add the on-chip regulators first for bootstrapping */
 380         ret = mfd_add_devices(wm8994->dev, -1,
 381                               wm8994_regulator_devs,
 382                               ARRAY_SIZE(wm8994_regulator_devs),
 383                               NULL, 0);
 384         if (ret != 0) {
 385                 dev_err(wm8994->dev, "Failed to add children: %d\n", ret);
 386                 goto err_regmap;
 387         }
 388
 389         switch (wm8994->type) {
 390         case WM1811:
 391                 wm8994->num_supplies = ARRAY_SIZE(wm1811_main_supplies);
 392                 break;
 393         case WM8994:
 394                 wm8994->num_supplies = ARRAY_SIZE(wm8994_main_supplies);
 395                 break;
 396         case WM8958:
 397                 wm8994->num_supplies = ARRAY_SIZE(wm8958_main_supplies);
 398                 break;
 399         default:
 400                 BUG();
 401                 goto err_regmap;
 402         }
 403
 404         wm8994->supplies = kzalloc(sizeof(struct regulator_bulk_data) *
 405                                    wm8994->num_supplies,
 406                                    GFP_KERNEL);
 407         if (!wm8994->supplies) {
 408                 ret = -ENOMEM;
 409                 goto err_regmap;
 410         }
 411
 412         switch (wm8994->type) {
 413         case WM1811:
 414                 for (i = 0; i < ARRAY_SIZE(wm1811_main_supplies); i++)
 415                         wm8994->supplies[i].supply = wm1811_main_supplies[i];
 416                 break;
 417         case WM8994:
 418                 for (i = 0; i < ARRAY_SIZE(wm8994_main_supplies); i++)
 419                         wm8994->supplies[i].supply = wm8994_main_supplies[i];
 420                 break;
 421         case WM8958:
 422                 for (i = 0; i < ARRAY_SIZE(wm8958_main_supplies); i++)
 423                         wm8994->supplies[i].supply = wm8958_main_supplies[i];
 424                 break;
 425         default:
 426                 BUG();
 427                 goto err_regmap;
 428         }
 429
 430         ret = regulator_bulk_get(wm8994->dev, wm8994->num_supplies,
 431                                  wm8994->supplies);
 432         if (ret != 0) {
 433                 dev_err(wm8994->dev, "Failed to get supplies: %d\n", ret);
 434                 goto err_supplies;
 435         }
 436
 437         ret = regulator_bulk_enable(wm8994->num_supplies,
 438                                     wm8994->supplies);
 439         if (ret != 0) {
 440                 dev_err(wm8994->dev, "Failed to enable supplies: %d\n", ret);
 441                 goto err_get;
 442         }
 443
 444         ret = wm8994_reg_read(wm8994, WM8994_SOFTWARE_RESET);
 445         if (ret < 0) {
 446                 dev_err(wm8994->dev, "Failed to read ID register\n");
 447                 goto err_enable;
 448         }
 449         switch (ret) {
 450         case 0x1811:
 451                 devname = "WM1811";
 452                 if (wm8994->type != WM1811)
 453                         dev_warn(wm8994->dev, "Device registered as type %d\n",
 454                                  wm8994->type);
 455                 wm8994->type = WM1811;
 456                 break;
 457         case 0x8994:
 458                 devname = "WM8994";
 459                 if (wm8994->type != WM8994)
 460                         dev_warn(wm8994->dev, "Device registered as type %d\n",
 461                                  wm8994->type);
 462                 wm8994->type = WM8994;
 463                 break;
 464         case 0x8958:
 465                 devname = "WM8958";
 466                 if (wm8994->type != WM8958)
 467                         dev_warn(wm8994->dev, "Device registered as type %d\n",
 468                                  wm8994->type);
 469                 wm8994->type = WM8958;
 470                 break;
 471         default:
 472                 dev_err(wm8994->dev, "Device is not a WM8994, ID is %x\n",
 473                         ret);
 474                 ret = -EINVAL;
 475                 goto err_enable;
 476         }
 477
 478         ret = wm8994_reg_read(wm8994, WM8994_CHIP_REVISION);
 479         if (ret < 0) {
 480                 dev_err(wm8994->dev, "Failed to read revision register: %d\n",
 481                         ret);
 482                 goto err_enable;
 483         }
 484
 485         switch (wm8994->type) {
 486         case WM8994:
 487                 switch (ret) {
 488                 case 0:
 489                 case 1:
 490                         dev_warn(wm8994->dev,
 491                                  "revision %c not fully supported\n",
 492                                  'A' + ret);
 493                         break;
 494                 default:
 495                         break;
 496                 }
 497                 break;
 498         default:
 499                 break;
 500         }
 501
 502         dev_info(wm8994->dev, "%s revision %c\n", devname, 'A' + ret);
 503
 504         if (pdata) {
 505                 wm8994->irq_base = pdata->irq_base;
 506                 wm8994->gpio_base = pdata->gpio_base;
 507
 508                 /* GPIO configuration is only applied if it's non-zero */
 509                 for (i = 0; i < ARRAY_SIZE(pdata->gpio_defaults); i++) {
 510                         if (pdata->gpio_defaults[i]) {
 511                                 wm8994_set_bits(wm8994, WM8994_GPIO_1 + i,
 512                                                 0xffff,
 513                                                 pdata->gpio_defaults[i]);
 514                         }
 515                 }
 516
 517                 wm8994->ldo_ena_always_driven = pdata->ldo_ena_always_driven;
 518         }
 519
 520         /* Disable LDO pulldowns while the device is active */
 521         wm8994_set_bits(wm8994, WM8994_PULL_CONTROL_2,
 522                         WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD,
 523                         0);
 524
 525         /* In some system designs where the regulators are not in use,
 526          * we can achieve a small reduction in leakage currents by
 527          * floating LDO outputs.  This bit makes no difference if the
 528          * LDOs are enabled, it only affects cases where the LDOs were
 529          * in operation and are then disabled.
 530          */
 531         for (i = 0; i < WM8994_NUM_LDO_REGS; i++) {
 532                 if (wm8994_ldo_in_use(pdata, i))
 533                         wm8994_set_bits(wm8994, WM8994_LDO_1 + i,
 534                                         WM8994_LDO1_DISCH, WM8994_LDO1_DISCH);
 535                 else
 536                         wm8994_set_bits(wm8994, WM8994_LDO_1 + i,
 537                                         WM8994_LDO1_DISCH, 0);
 538         }
 539
 540         wm8994_irq_init(wm8994);
 541
 542         ret = mfd_add_devices(wm8994->dev, -1,
 543                               wm8994_devs, ARRAY_SIZE(wm8994_devs),
 544                               NULL, 0);
 545         if (ret != 0) {
 546                 dev_err(wm8994->dev, "Failed to add children: %d\n", ret);
 547                 goto err_irq;
 548         }
 549
 550         pm_runtime_enable(wm8994->dev);
 551         pm_runtime_resume(wm8994->dev);
 552
 553         return 0;
 554
 555 err_irq:
 556         wm8994_irq_exit(wm8994);
 557 err_enable:
 558         regulator_bulk_disable(wm8994->num_supplies,
 559                                wm8994->supplies);
 560 err_get:
 561         regulator_bulk_free(wm8994->num_supplies, wm8994->supplies);
 562 err_supplies:
 563         kfree(wm8994->supplies);
 564 err_regmap:
 565         regmap_exit(wm8994->regmap);
 566         mfd_remove_devices(wm8994->dev);
 567         kfree(wm8994);
 568         return ret;
 569 }
 570
 571 static void wm8994_device_exit(struct wm8994 *wm8994)
 572 {
 573         pm_runtime_disable(wm8994->dev);
 574         mfd_remove_devices(wm8994->dev);
 575         wm8994_irq_exit(wm8994);
 576         regulator_bulk_disable(wm8994->num_supplies,
 577                                wm8994->supplies);
 578         regulator_bulk_free(wm8994->num_supplies, wm8994->supplies);
 579         kfree(wm8994->supplies);
 580         regmap_exit(wm8994->regmap);
 581         kfree(wm8994);
 582 }
 583
 584 static int wm8994_i2c_probe(struct i2c_client *i2c,
 585                             const struct i2c_device_id *id)
 586 {
 587         struct wm8994 *wm8994;
 588         int ret;
 589
 590         wm8994 = kzalloc(sizeof(struct wm8994), GFP_KERNEL);
 591         if (wm8994 == NULL)
 592                 return -ENOMEM;
 593
 594         i2c_set_clientdata(i2c, wm8994);
 595         wm8994->dev = &i2c->dev;
 596         wm8994->irq = i2c->irq;
 597         wm8994->type = id->driver_data;
 598
 599         wm8994->regmap = regmap_init_i2c(i2c, &wm8994_regmap_config);
 600         if (IS_ERR(wm8994->regmap)) {
 601                 ret = PTR_ERR(wm8994->regmap);
 602                 dev_err(wm8994->dev, "Failed to allocate register map: %d\n",
 603                         ret);
 604                 kfree(wm8994);
 605                 return ret;
 606         }
 607
 608         return wm8994_device_init(wm8994, i2c->irq);
 609 }
 610
 611 static int wm8994_i2c_remove(struct i2c_client *i2c)
 612 {
 613         struct wm8994 *wm8994 = i2c_get_clientdata(i2c);
 614
 615         wm8994_device_exit(wm8994);
 616
 617         return 0;
 618 }
 619
 620 static const struct i2c_device_id wm8994_i2c_id[] = {
 621         { "wm1811", WM1811 },
 622         { "wm8994", WM8994 },
 623         { "wm8958", WM8958 },
 624         { }
 625 };
 626 MODULE_DEVICE_TABLE(i2c, wm8994_i2c_id);
 627
 628 static UNIVERSAL_DEV_PM_OPS(wm8994_pm_ops, wm8994_suspend, wm8994_resume,
 629                             NULL);
 630
 631 static struct i2c_driver wm8994_i2c_driver = {
 632         .driver = {
 633                 .name = "wm8994",
 634                 .owner = THIS_MODULE,
 635                 .pm = &wm8994_pm_ops,
 636         },
 637         .probe = wm8994_i2c_probe,
 638         .remove = wm8994_i2c_remove,
 639         .id_table = wm8994_i2c_id,
 640 };
 641
 642 static int __init wm8994_i2c_init(void)
 643 {
 644         int ret;
 645
 646         ret = i2c_add_driver(&wm8994_i2c_driver);
 647         if (ret != 0)
 648                 pr_err("Failed to register wm8994 I2C driver: %d\n", ret);
 649
 650         return ret;
 651 }
 652 module_init(wm8994_i2c_init);
 653
 654 static void __exit wm8994_i2c_exit(void)
 655 {
 656         i2c_del_driver(&wm8994_i2c_driver);
 657 }
 658 module_exit(wm8994_i2c_exit);
 659
 660 MODULE_DESCRIPTION("Core support for the WM8994 audio CODEC");
 661 MODULE_LICENSE("GPL");
 662 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");