drivers/gpio/gpio-sx150x.c

   1 /* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License version 2 and
   5  * only version 2 as published by the Free Software Foundation.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  *
  12  * You should have received a copy of the GNU General Public License
  13  * along with this program; if not, write to the Free Software
  14  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  15  * 02110-1301, USA.
  16  */
  17 #include <linux/gpio.h>
  18 #include <linux/i2c.h>
  19 #include <linux/init.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/irq.h>
  22 #include <linux/module.h>
  23 #include <linux/mutex.h>
  24 #include <linux/slab.h>
  25 #include <linux/workqueue.h>
  26 #include <linux/i2c/sx150x.h>
  27
  28 #define NO_UPDATE_PENDING       -1
  29
  30 struct sx150x_device_data {
  31         u8 reg_pullup;
  32         u8 reg_pulldn;
  33         u8 reg_drain;
  34         u8 reg_polarity;
  35         u8 reg_dir;
  36         u8 reg_data;
  37         u8 reg_irq_mask;
  38         u8 reg_irq_src;
  39         u8 reg_sense;
  40         u8 reg_clock;
  41         u8 reg_misc;
  42         u8 reg_reset;
  43         u8 ngpios;
  44 };
  45
  46 struct sx150x_chip {
  47         struct gpio_chip                 gpio_chip;
  48         struct i2c_client               *client;
  49         const struct sx150x_device_data *dev_cfg;
  50         int                              irq_summary;
  51         int                              irq_base;
  52         int                              irq_update;
  53         u32                              irq_sense;
  54         u32                              irq_masked;
  55         u32                              dev_sense;
  56         u32                              dev_masked;
  57         struct irq_chip                  irq_chip;
  58         struct mutex                     lock;
  59 };
  60
  61 static const struct sx150x_device_data sx150x_devices[] = {
  62         [0] = { /* sx1508q */
  63                 .reg_pullup   = 0x03,
  64                 .reg_pulldn   = 0x04,
  65                 .reg_drain    = 0x05,
  66                 .reg_polarity = 0x06,
  67                 .reg_dir      = 0x07,
  68                 .reg_data     = 0x08,
  69                 .reg_irq_mask = 0x09,
  70                 .reg_irq_src  = 0x0c,
  71                 .reg_sense    = 0x0b,
  72                 .reg_clock    = 0x0f,
  73                 .reg_misc     = 0x10,
  74                 .reg_reset    = 0x7d,
  75                 .ngpios       = 8
  76         },
  77         [1] = { /* sx1509q */
  78                 .reg_pullup   = 0x07,
  79                 .reg_pulldn   = 0x09,
  80                 .reg_drain    = 0x0b,
  81                 .reg_polarity = 0x0d,
  82                 .reg_dir      = 0x0f,
  83                 .reg_data     = 0x11,
  84                 .reg_irq_mask = 0x13,
  85                 .reg_irq_src  = 0x19,
  86                 .reg_sense    = 0x17,
  87                 .reg_clock    = 0x1e,
  88                 .reg_misc     = 0x1f,
  89                 .reg_reset    = 0x7d,
  90                 .ngpios       = 16
  91         },
  92 };
  93
  94 static const struct i2c_device_id sx150x_id[] = {
  95         {"sx1508q", 0},
  96         {"sx1509q", 1},
  97         {}
  98 };
  99 MODULE_DEVICE_TABLE(i2c, sx150x_id);
 100
 101 static s32 sx150x_i2c_write(struct i2c_client *client, u8 reg, u8 val)
 102 {
 103         s32 err = i2c_smbus_write_byte_data(client, reg, val);
 104
 105         if (err < 0)
 106                 dev_warn(&client->dev,
 107                         "i2c write fail: can't write %02x to %02x: %d\n",
 108                         val, reg, err);
 109         return err;
 110 }
 111
 112 static s32 sx150x_i2c_read(struct i2c_client *client, u8 reg, u8 *val)
 113 {
 114         s32 err = i2c_smbus_read_byte_data(client, reg);
 115
 116         if (err >= 0)
 117                 *val = err;
 118         else
 119                 dev_warn(&client->dev,
 120                         "i2c read fail: can't read from %02x: %d\n",
 121                         reg, err);
 122         return err;
 123 }
 124
 125 static inline bool offset_is_oscio(struct sx150x_chip *chip, unsigned offset)
 126 {
 127         return (chip->dev_cfg->ngpios == offset);
 128 }
 129
 130 /*
 131  * These utility functions solve the common problem of locating and setting
 132  * configuration bits.  Configuration bits are grouped into registers
 133  * whose indexes increase downwards.  For example, with eight-bit registers,
 134  * sixteen gpios would have their config bits grouped in the following order:
 135  * REGISTER N-1 [ f e d c b a 9 8 ]
 136  *          N   [ 7 6 5 4 3 2 1 0 ]
 137  *
 138  * For multi-bit configurations, the pattern gets wider:
 139  * REGISTER N-3 [ f f e e d d c c ]
 140  *          N-2 [ b b a a 9 9 8 8 ]
 141  *          N-1 [ 7 7 6 6 5 5 4 4 ]
 142  *          N   [ 3 3 2 2 1 1 0 0 ]
 143  *
 144  * Given the address of the starting register 'N', the index of the gpio
 145  * whose configuration we seek to change, and the width in bits of that
 146  * configuration, these functions allow us to locate the correct
 147  * register and mask the correct bits.
 148  */
 149 static inline void sx150x_find_cfg(u8 offset, u8 width,
 150                                 u8 *reg, u8 *mask, u8 *shift)
 151 {
 152         *reg   -= offset * width / 8;
 153         *mask   = (1 << width) - 1;
 154         *shift  = (offset * width) % 8;
 155         *mask <<= *shift;
 156 }
 157
 158 static s32 sx150x_write_cfg(struct sx150x_chip *chip,
 159                         u8 offset, u8 width, u8 reg, u8 val)
 160 {
 161         u8  mask;
 162         u8  data;
 163         u8  shift;
 164         s32 err;
 165
 166         sx150x_find_cfg(offset, width, &reg, &mask, &shift);
 167         err = sx150x_i2c_read(chip->client, reg, &data);
 168         if (err < 0)
 169                 return err;
 170
 171         data &= ~mask;
 172         data |= (val << shift) & mask;
 173         return sx150x_i2c_write(chip->client, reg, data);
 174 }
 175
 176 static int sx150x_get_io(struct sx150x_chip *chip, unsigned offset)
 177 {
 178         u8  reg = chip->dev_cfg->reg_data;
 179         u8  mask;
 180         u8  data;
 181         u8  shift;
 182         s32 err;
 183
 184         sx150x_find_cfg(offset, 1, &reg, &mask, &shift);
 185         err = sx150x_i2c_read(chip->client, reg, &data);
 186         if (err >= 0)
 187                 err = (data & mask) != 0 ? 1 : 0;
 188
 189         return err;
 190 }
 191
 192 static void sx150x_set_oscio(struct sx150x_chip *chip, int val)
 193 {
 194         sx150x_i2c_write(chip->client,
 195                         chip->dev_cfg->reg_clock,
 196                         (val ? 0x1f : 0x10));
 197 }
 198
 199 static void sx150x_set_io(struct sx150x_chip *chip, unsigned offset, int val)
 200 {
 201         sx150x_write_cfg(chip,
 202                         offset,
 203                         1,
 204                         chip->dev_cfg->reg_data,
 205                         (val ? 1 : 0));
 206 }
 207
 208 static int sx150x_io_input(struct sx150x_chip *chip, unsigned offset)
 209 {
 210         return sx150x_write_cfg(chip,
 211                                 offset,
 212                                 1,
 213                                 chip->dev_cfg->reg_dir,
 214                                 1);
 215 }
 216
 217 static int sx150x_io_output(struct sx150x_chip *chip, unsigned offset, int val)
 218 {
 219         int err;
 220
 221         err = sx150x_write_cfg(chip,
 222                         offset,
 223                         1,
 224                         chip->dev_cfg->reg_data,
 225                         (val ? 1 : 0));
 226         if (err >= 0)
 227                 err = sx150x_write_cfg(chip,
 228                                 offset,
 229                                 1,
 230                                 chip->dev_cfg->reg_dir,
 231                                 0);
 232         return err;
 233 }
 234
 235 static int sx150x_gpio_get(struct gpio_chip *gc, unsigned offset)
 236 {
 237         struct sx150x_chip *chip;
 238         int status = -EINVAL;
 239
 240         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 241
 242         if (!offset_is_oscio(chip, offset)) {
 243                 mutex_lock(&chip->lock);
 244                 status = sx150x_get_io(chip, offset);
 245                 mutex_unlock(&chip->lock);
 246         }
 247
 248         return status;
 249 }
 250
 251 static void sx150x_gpio_set(struct gpio_chip *gc, unsigned offset, int val)
 252 {
 253         struct sx150x_chip *chip;
 254
 255         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 256
 257         mutex_lock(&chip->lock);
 258         if (offset_is_oscio(chip, offset))
 259                 sx150x_set_oscio(chip, val);
 260         else
 261                 sx150x_set_io(chip, offset, val);
 262         mutex_unlock(&chip->lock);
 263 }
 264
 265 static int sx150x_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
 266 {
 267         struct sx150x_chip *chip;
 268         int status = -EINVAL;
 269
 270         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 271
 272         if (!offset_is_oscio(chip, offset)) {
 273                 mutex_lock(&chip->lock);
 274                 status = sx150x_io_input(chip, offset);
 275                 mutex_unlock(&chip->lock);
 276         }
 277         return status;
 278 }
 279
 280 static int sx150x_gpio_direction_output(struct gpio_chip *gc,
 281                                         unsigned offset,
 282                                         int val)
 283 {
 284         struct sx150x_chip *chip;
 285         int status = 0;
 286
 287         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 288
 289         if (!offset_is_oscio(chip, offset)) {
 290                 mutex_lock(&chip->lock);
 291                 status = sx150x_io_output(chip, offset, val);
 292                 mutex_unlock(&chip->lock);
 293         }
 294         return status;
 295 }
 296
 297 static int sx150x_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
 298 {
 299         struct sx150x_chip *chip;
 300
 301         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 302
 303         if (offset >= chip->dev_cfg->ngpios)
 304                 return -EINVAL;
 305
 306         if (chip->irq_base < 0)
 307                 return -EINVAL;
 308
 309         return chip->irq_base + offset;
 310 }
 311
 312 static void sx150x_irq_mask(struct irq_data *d)
 313 {
 314         struct irq_chip *ic = irq_data_get_irq_chip(d);
 315         struct sx150x_chip *chip;
 316         unsigned n;
 317
 318         chip = container_of(ic, struct sx150x_chip, irq_chip);
 319         n = d->irq - chip->irq_base;
 320         chip->irq_masked |= (1 << n);
 321         chip->irq_update = n;
 322 }
 323
 324 static void sx150x_irq_unmask(struct irq_data *d)
 325 {
 326         struct irq_chip *ic = irq_data_get_irq_chip(d);
 327         struct sx150x_chip *chip;
 328         unsigned n;
 329
 330         chip = container_of(ic, struct sx150x_chip, irq_chip);
 331         n = d->irq - chip->irq_base;
 332
 333         chip->irq_masked &= ~(1 << n);
 334         chip->irq_update = n;
 335 }
 336
 337 static int sx150x_irq_set_type(struct irq_data *d, unsigned int flow_type)
 338 {
 339         struct irq_chip *ic = irq_data_get_irq_chip(d);
 340         struct sx150x_chip *chip;
 341         unsigned n, val = 0;
 342
 343         if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
 344                 return -EINVAL;
 345
 346         chip = container_of(ic, struct sx150x_chip, irq_chip);
 347         n = d->irq - chip->irq_base;
 348
 349         if (flow_type & IRQ_TYPE_EDGE_RISING)
 350                 val |= 0x1;
 351         if (flow_type & IRQ_TYPE_EDGE_FALLING)
 352                 val |= 0x2;
 353
 354         chip->irq_sense &= ~(3UL << (n * 2));
 355         chip->irq_sense |= val << (n * 2);
 356         chip->irq_update = n;
 357         return 0;
 358 }
 359
 360 static irqreturn_t sx150x_irq_thread_fn(int irq, void *dev_id)
 361 {
 362         struct sx150x_chip *chip = (struct sx150x_chip *)dev_id;
 363         unsigned nhandled = 0;
 364         unsigned sub_irq;
 365         unsigned n;
 366         s32 err;
 367         u8 val;
 368         int i;
 369
 370         for (i = (chip->dev_cfg->ngpios / 8) - 1; i >= 0; --i) {
 371                 err = sx150x_i2c_read(chip->client,
 372                                       chip->dev_cfg->reg_irq_src - i,
 373                                       &val);
 374                 if (err < 0)
 375                         continue;
 376
 377                 sx150x_i2c_write(chip->client,
 378                                 chip->dev_cfg->reg_irq_src - i,
 379                                 val);
 380                 for (n = 0; n < 8; ++n) {
 381                         if (val & (1 << n)) {
 382                                 sub_irq = chip->irq_base + (i * 8) + n;
 383                                 handle_nested_irq(sub_irq);
 384                                 ++nhandled;
 385                         }
 386                 }
 387         }
 388
 389         return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
 390 }
 391
 392 static void sx150x_irq_bus_lock(struct irq_data *d)
 393 {
 394         struct irq_chip *ic = irq_data_get_irq_chip(d);
 395         struct sx150x_chip *chip;
 396
 397         chip = container_of(ic, struct sx150x_chip, irq_chip);
 398
 399         mutex_lock(&chip->lock);
 400 }
 401
 402 static void sx150x_irq_bus_sync_unlock(struct irq_data *d)
 403 {
 404         struct irq_chip *ic = irq_data_get_irq_chip(d);
 405         struct sx150x_chip *chip;
 406         unsigned n;
 407
 408         chip = container_of(ic, struct sx150x_chip, irq_chip);
 409
 410         if (chip->irq_update == NO_UPDATE_PENDING)
 411                 goto out;
 412
 413         n = chip->irq_update;
 414         chip->irq_update = NO_UPDATE_PENDING;
 415
 416         /* Avoid updates if nothing changed */
 417         if (chip->dev_sense == chip->irq_sense &&
 418             chip->dev_sense == chip->irq_masked)
 419                 goto out;
 420
 421         chip->dev_sense = chip->irq_sense;
 422         chip->dev_masked = chip->irq_masked;
 423
 424         if (chip->irq_masked & (1 << n)) {
 425                 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1);
 426                 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0);
 427         } else {
 428                 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0);
 429                 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense,
 430                                  chip->irq_sense >> (n * 2));
 431         }
 432 out:
 433         mutex_unlock(&chip->lock);
 434 }
 435
 436 static void sx150x_init_chip(struct sx150x_chip *chip,
 437                         struct i2c_client *client,
 438                         kernel_ulong_t driver_data,
 439                         struct sx150x_platform_data *pdata)
 440 {
 441         mutex_init(&chip->lock);
 442
 443         chip->client                     = client;
 444         chip->dev_cfg                    = &sx150x_devices[driver_data];
 445         chip->gpio_chip.label            = client->name;
 446         chip->gpio_chip.direction_input  = sx150x_gpio_direction_input;
 447         chip->gpio_chip.direction_output = sx150x_gpio_direction_output;
 448         chip->gpio_chip.get              = sx150x_gpio_get;
 449         chip->gpio_chip.set              = sx150x_gpio_set;
 450         chip->gpio_chip.to_irq           = sx150x_gpio_to_irq;
 451         chip->gpio_chip.base             = pdata->gpio_base;
 452         chip->gpio_chip.can_sleep        = 1;
 453         chip->gpio_chip.ngpio            = chip->dev_cfg->ngpios;
 454         if (pdata->oscio_is_gpo)
 455                 ++chip->gpio_chip.ngpio;
 456
 457         chip->irq_chip.name                = client->name;
 458         chip->irq_chip.irq_mask            = sx150x_irq_mask;
 459         chip->irq_chip.irq_unmask          = sx150x_irq_unmask;
 460         chip->irq_chip.irq_set_type        = sx150x_irq_set_type;
 461         chip->irq_chip.irq_bus_lock        = sx150x_irq_bus_lock;
 462         chip->irq_chip.irq_bus_sync_unlock = sx150x_irq_bus_sync_unlock;
 463         chip->irq_summary                  = -1;
 464         chip->irq_base                     = -1;
 465         chip->irq_masked                   = ~0;
 466         chip->irq_sense                    = 0;
 467         chip->dev_masked                   = ~0;
 468         chip->dev_sense                    = 0;
 469         chip->irq_update                   = NO_UPDATE_PENDING;
 470 }
 471
 472 static int sx150x_init_io(struct sx150x_chip *chip, u8 base, u16 cfg)
 473 {
 474         int err = 0;
 475         unsigned n;
 476
 477         for (n = 0; err >= 0 && n < (chip->dev_cfg->ngpios / 8); ++n)
 478                 err = sx150x_i2c_write(chip->client, base - n, cfg >> (n * 8));
 479         return err;
 480 }
 481
 482 static int sx150x_reset(struct sx150x_chip *chip)
 483 {
 484         int err;
 485
 486         err = i2c_smbus_write_byte_data(chip->client,
 487                                         chip->dev_cfg->reg_reset,
 488                                         0x12);
 489         if (err < 0)
 490                 return err;
 491
 492         err = i2c_smbus_write_byte_data(chip->client,
 493                                         chip->dev_cfg->reg_reset,
 494                                         0x34);
 495         return err;
 496 }
 497
 498 static int sx150x_init_hw(struct sx150x_chip *chip,
 499                         struct sx150x_platform_data *pdata)
 500 {
 501         int err = 0;
 502
 503         if (pdata->reset_during_probe) {
 504                 err = sx150x_reset(chip);
 505                 if (err < 0)
 506                         return err;
 507         }
 508
 509         err = sx150x_i2c_write(chip->client,
 510                         chip->dev_cfg->reg_misc,
 511                         0x01);
 512         if (err < 0)
 513                 return err;
 514
 515         err = sx150x_init_io(chip, chip->dev_cfg->reg_pullup,
 516                         pdata->io_pullup_ena);
 517         if (err < 0)
 518                 return err;
 519
 520         err = sx150x_init_io(chip, chip->dev_cfg->reg_pulldn,
 521                         pdata->io_pulldn_ena);
 522         if (err < 0)
 523                 return err;
 524
 525         err = sx150x_init_io(chip, chip->dev_cfg->reg_drain,
 526                         pdata->io_open_drain_ena);
 527         if (err < 0)
 528                 return err;
 529
 530         err = sx150x_init_io(chip, chip->dev_cfg->reg_polarity,
 531                         pdata->io_polarity);
 532         if (err < 0)
 533                 return err;
 534
 535         if (pdata->oscio_is_gpo)
 536                 sx150x_set_oscio(chip, 0);
 537
 538         return err;
 539 }
 540
 541 static int sx150x_install_irq_chip(struct sx150x_chip *chip,
 542                                 int irq_summary,
 543                                 int irq_base)
 544 {
 545         int err;
 546         unsigned n;
 547         unsigned irq;
 548
 549         chip->irq_summary = irq_summary;
 550         chip->irq_base    = irq_base;
 551
 552         for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
 553                 irq = irq_base + n;
 554                 irq_set_chip_and_handler(irq, &chip->irq_chip, handle_edge_irq);
 555                 irq_set_nested_thread(irq, 1);
 556 #ifdef CONFIG_ARM
 557                 set_irq_flags(irq, IRQF_VALID);
 558 #else
 559                 irq_set_noprobe(irq);
 560 #endif
 561         }
 562
 563         err = request_threaded_irq(irq_summary,
 564                                 NULL,
 565                                 sx150x_irq_thread_fn,
 566                                 IRQF_SHARED | IRQF_TRIGGER_FALLING,
 567                                 chip->irq_chip.name,
 568                                 chip);
 569         if (err < 0) {
 570                 chip->irq_summary = -1;
 571                 chip->irq_base    = -1;
 572         }
 573
 574         return err;
 575 }
 576
 577 static void sx150x_remove_irq_chip(struct sx150x_chip *chip)
 578 {
 579         unsigned n;
 580         unsigned irq;
 581
 582         free_irq(chip->irq_summary, chip);
 583
 584         for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
 585                 irq = chip->irq_base + n;
 586                 irq_set_chip_and_handler(irq, NULL, NULL);
 587         }
 588 }
 589
 590 static int __devinit sx150x_probe(struct i2c_client *client,
 591                                 const struct i2c_device_id *id)
 592 {
 593         static const u32 i2c_funcs = I2C_FUNC_SMBUS_BYTE_DATA |
 594                                      I2C_FUNC_SMBUS_WRITE_WORD_DATA;
 595         struct sx150x_platform_data *pdata;
 596         struct sx150x_chip *chip;
 597         int rc;
 598
 599         pdata = client->dev.platform_data;
 600         if (!pdata)
 601                 return -EINVAL;
 602
 603         if (!i2c_check_functionality(client->adapter, i2c_funcs))
 604                 return -ENOSYS;
 605
 606         chip = kzalloc(sizeof(struct sx150x_chip), GFP_KERNEL);
 607         if (!chip)
 608                 return -ENOMEM;
 609
 610         sx150x_init_chip(chip, client, id->driver_data, pdata);
 611         rc = sx150x_init_hw(chip, pdata);
 612         if (rc < 0)
 613                 goto probe_fail_pre_gpiochip_add;
 614
 615         rc = gpiochip_add(&chip->gpio_chip);
 616         if (rc < 0)
 617                 goto probe_fail_pre_gpiochip_add;
 618
 619         if (pdata->irq_summary >= 0) {
 620                 rc = sx150x_install_irq_chip(chip,
 621                                         pdata->irq_summary,
 622                                         pdata->irq_base);
 623                 if (rc < 0)
 624                         goto probe_fail_post_gpiochip_add;
 625         }
 626
 627         i2c_set_clientdata(client, chip);
 628
 629         return 0;
 630 probe_fail_post_gpiochip_add:
 631         WARN_ON(gpiochip_remove(&chip->gpio_chip) < 0);
 632 probe_fail_pre_gpiochip_add:
 633         kfree(chip);
 634         return rc;
 635 }
 636
 637 static int __devexit sx150x_remove(struct i2c_client *client)
 638 {
 639         struct sx150x_chip *chip;
 640         int rc;
 641
 642         chip = i2c_get_clientdata(client);
 643         rc = gpiochip_remove(&chip->gpio_chip);
 644         if (rc < 0)
 645                 return rc;
 646
 647         if (chip->irq_summary >= 0)
 648                 sx150x_remove_irq_chip(chip);
 649
 650         kfree(chip);
 651
 652         return 0;
 653 }
 654
 655 static struct i2c_driver sx150x_driver = {
 656         .driver = {
 657                 .name = "sx150x",
 658                 .owner = THIS_MODULE
 659         },
 660         .probe    = sx150x_probe,
 661         .remove   = __devexit_p(sx150x_remove),
 662         .id_table = sx150x_id,
 663 };
 664
 665 static int __init sx150x_init(void)
 666 {
 667         return i2c_add_driver(&sx150x_driver);
 668 }
 669 subsys_initcall(sx150x_init);
 670
 671 static void __exit sx150x_exit(void)
 672 {
 673         return i2c_del_driver(&sx150x_driver);
 674 }
 675 module_exit(sx150x_exit);
 676
 677 MODULE_AUTHOR("Gregory Bean <gbean@codeaurora.org>");
 678 MODULE_DESCRIPTION("Driver for Semtech SX150X I2C GPIO Expanders");
 679 MODULE_LICENSE("GPL v2");
 680 MODULE_ALIAS("i2c:sx150x");