drivers/gpio/gpio-mcp23s08.c

   1 /*
   2  * MCP23S08 SPI/GPIO gpio expander driver
   3  */
   4
   5 #include <linux/kernel.h>
   6 #include <linux/device.h>
   7 #include <linux/mutex.h>
   8 #include <linux/module.h>
   9 #include <linux/gpio.h>
  10 #include <linux/i2c.h>
  11 #include <linux/spi/spi.h>
  12 #include <linux/spi/mcp23s08.h>
  13 #include <linux/slab.h>
  14 #include <asm/byteorder.h>
  15
  16 /**
  17  * MCP types supported by driver
  18  */
  19 #define MCP_TYPE_S08    0
  20 #define MCP_TYPE_S17    1
  21 #define MCP_TYPE_008    2
  22 #define MCP_TYPE_017    3
  23
  24 /* Registers are all 8 bits wide.
  25  *
  26  * The mcp23s17 has twice as many bits, and can be configured to work
  27  * with either 16 bit registers or with two adjacent 8 bit banks.
  28  */
  29 #define MCP_IODIR       0x00            /* init/reset:  all ones */
  30 #define MCP_IPOL        0x01
  31 #define MCP_GPINTEN     0x02
  32 #define MCP_DEFVAL      0x03
  33 #define MCP_INTCON      0x04
  34 #define MCP_IOCON       0x05
  35 #       define IOCON_SEQOP      (1 << 5)
  36 #       define IOCON_HAEN       (1 << 3)
  37 #       define IOCON_ODR        (1 << 2)
  38 #       define IOCON_INTPOL     (1 << 1)
  39 #define MCP_GPPU        0x06
  40 #define MCP_INTF        0x07
  41 #define MCP_INTCAP      0x08
  42 #define MCP_GPIO        0x09
  43 #define MCP_OLAT        0x0a
  44
  45 struct mcp23s08;
  46
  47 struct mcp23s08_ops {
  48         int     (*read)(struct mcp23s08 *mcp, unsigned reg);
  49         int     (*write)(struct mcp23s08 *mcp, unsigned reg, unsigned val);
  50         int     (*read_regs)(struct mcp23s08 *mcp, unsigned reg,
  51                              u16 *vals, unsigned n);
  52 };
  53
  54 struct mcp23s08 {
  55         u8                      addr;
  56
  57         u16                     cache[11];
  58         /* lock protects the cached values */
  59         struct mutex            lock;
  60
  61         struct gpio_chip        chip;
  62
  63         const struct mcp23s08_ops       *ops;
  64         void                    *data; /* ops specific data */
  65 };
  66
  67 /* A given spi_device can represent up to eight mcp23sxx chips
  68  * sharing the same chipselect but using different addresses
  69  * (e.g. chips #0 and #3 might be populated, but not #1 or $2).
  70  * Driver data holds all the per-chip data.
  71  */
  72 struct mcp23s08_driver_data {
  73         unsigned                ngpio;
  74         struct mcp23s08         *mcp[8];
  75         struct mcp23s08         chip[];
  76 };
  77
  78 /*----------------------------------------------------------------------*/
  79
  80 #ifdef CONFIG_I2C
  81
  82 static int mcp23008_read(struct mcp23s08 *mcp, unsigned reg)
  83 {
  84         return i2c_smbus_read_byte_data(mcp->data, reg);
  85 }
  86
  87 static int mcp23008_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
  88 {
  89         return i2c_smbus_write_byte_data(mcp->data, reg, val);
  90 }
  91
  92 static int
  93 mcp23008_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
  94 {
  95         while (n--) {
  96                 int ret = mcp23008_read(mcp, reg++);
  97                 if (ret < 0)
  98                         return ret;
  99                 *vals++ = ret;
 100         }
 101
 102         return 0;
 103 }
 104
 105 static int mcp23017_read(struct mcp23s08 *mcp, unsigned reg)
 106 {
 107         return i2c_smbus_read_word_data(mcp->data, reg << 1);
 108 }
 109
 110 static int mcp23017_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
 111 {
 112         return i2c_smbus_write_word_data(mcp->data, reg << 1, val);
 113 }
 114
 115 static int
 116 mcp23017_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
 117 {
 118         while (n--) {
 119                 int ret = mcp23017_read(mcp, reg++);
 120                 if (ret < 0)
 121                         return ret;
 122                 *vals++ = ret;
 123         }
 124
 125         return 0;
 126 }
 127
 128 static const struct mcp23s08_ops mcp23008_ops = {
 129         .read           = mcp23008_read,
 130         .write          = mcp23008_write,
 131         .read_regs      = mcp23008_read_regs,
 132 };
 133
 134 static const struct mcp23s08_ops mcp23017_ops = {
 135         .read           = mcp23017_read,
 136         .write          = mcp23017_write,
 137         .read_regs      = mcp23017_read_regs,
 138 };
 139
 140 #endif /* CONFIG_I2C */
 141
 142 /*----------------------------------------------------------------------*/
 143
 144 #ifdef CONFIG_SPI_MASTER
 145
 146 static int mcp23s08_read(struct mcp23s08 *mcp, unsigned reg)
 147 {
 148         u8      tx[2], rx[1];
 149         int     status;
 150
 151         tx[0] = mcp->addr | 0x01;
 152         tx[1] = reg;
 153         status = spi_write_then_read(mcp->data, tx, sizeof tx, rx, sizeof rx);
 154         return (status < 0) ? status : rx[0];
 155 }
 156
 157 static int mcp23s08_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
 158 {
 159         u8      tx[3];
 160
 161         tx[0] = mcp->addr;
 162         tx[1] = reg;
 163         tx[2] = val;
 164         return spi_write_then_read(mcp->data, tx, sizeof tx, NULL, 0);
 165 }
 166
 167 static int
 168 mcp23s08_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
 169 {
 170         u8      tx[2], *tmp;
 171         int     status;
 172
 173         if ((n + reg) > sizeof mcp->cache)
 174                 return -EINVAL;
 175         tx[0] = mcp->addr | 0x01;
 176         tx[1] = reg;
 177
 178         tmp = (u8 *)vals;
 179         status = spi_write_then_read(mcp->data, tx, sizeof tx, tmp, n);
 180         if (status >= 0) {
 181                 while (n--)
 182                         vals[n] = tmp[n]; /* expand to 16bit */
 183         }
 184         return status;
 185 }
 186
 187 static int mcp23s17_read(struct mcp23s08 *mcp, unsigned reg)
 188 {
 189         u8      tx[2], rx[2];
 190         int     status;
 191
 192         tx[0] = mcp->addr | 0x01;
 193         tx[1] = reg << 1;
 194         status = spi_write_then_read(mcp->data, tx, sizeof tx, rx, sizeof rx);
 195         return (status < 0) ? status : (rx[0] | (rx[1] << 8));
 196 }
 197
 198 static int mcp23s17_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
 199 {
 200         u8      tx[4];
 201
 202         tx[0] = mcp->addr;
 203         tx[1] = reg << 1;
 204         tx[2] = val;
 205         tx[3] = val >> 8;
 206         return spi_write_then_read(mcp->data, tx, sizeof tx, NULL, 0);
 207 }
 208
 209 static int
 210 mcp23s17_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
 211 {
 212         u8      tx[2];
 213         int     status;
 214
 215         if ((n + reg) > sizeof mcp->cache)
 216                 return -EINVAL;
 217         tx[0] = mcp->addr | 0x01;
 218         tx[1] = reg << 1;
 219
 220         status = spi_write_then_read(mcp->data, tx, sizeof tx,
 221                                      (u8 *)vals, n * 2);
 222         if (status >= 0) {
 223                 while (n--)
 224                         vals[n] = __le16_to_cpu((__le16)vals[n]);
 225         }
 226
 227         return status;
 228 }
 229
 230 static const struct mcp23s08_ops mcp23s08_ops = {
 231         .read           = mcp23s08_read,
 232         .write          = mcp23s08_write,
 233         .read_regs      = mcp23s08_read_regs,
 234 };
 235
 236 static const struct mcp23s08_ops mcp23s17_ops = {
 237         .read           = mcp23s17_read,
 238         .write          = mcp23s17_write,
 239         .read_regs      = mcp23s17_read_regs,
 240 };
 241
 242 #endif /* CONFIG_SPI_MASTER */
 243
 244 /*----------------------------------------------------------------------*/
 245
 246 static int mcp23s08_direction_input(struct gpio_chip *chip, unsigned offset)
 247 {
 248         struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
 249         int status;
 250
 251         mutex_lock(&mcp->lock);
 252         mcp->cache[MCP_IODIR] |= (1 << offset);
 253         status = mcp->ops->write(mcp, MCP_IODIR, mcp->cache[MCP_IODIR]);
 254         mutex_unlock(&mcp->lock);
 255         return status;
 256 }
 257
 258 static int mcp23s08_get(struct gpio_chip *chip, unsigned offset)
 259 {
 260         struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
 261         int status;
 262
 263         mutex_lock(&mcp->lock);
 264
 265         /* REVISIT reading this clears any IRQ ... */
 266         status = mcp->ops->read(mcp, MCP_GPIO);
 267         if (status < 0)
 268                 status = 0;
 269         else {
 270                 mcp->cache[MCP_GPIO] = status;
 271                 status = !!(status & (1 << offset));
 272         }
 273         mutex_unlock(&mcp->lock);
 274         return status;
 275 }
 276
 277 static int __mcp23s08_set(struct mcp23s08 *mcp, unsigned mask, int value)
 278 {
 279         unsigned olat = mcp->cache[MCP_OLAT];
 280
 281         if (value)
 282                 olat |= mask;
 283         else
 284                 olat &= ~mask;
 285         mcp->cache[MCP_OLAT] = olat;
 286         return mcp->ops->write(mcp, MCP_OLAT, olat);
 287 }
 288
 289 static void mcp23s08_set(struct gpio_chip *chip, unsigned offset, int value)
 290 {
 291         struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
 292         unsigned mask = 1 << offset;
 293
 294         mutex_lock(&mcp->lock);
 295         __mcp23s08_set(mcp, mask, value);
 296         mutex_unlock(&mcp->lock);
 297 }
 298
 299 static int
 300 mcp23s08_direction_output(struct gpio_chip *chip, unsigned offset, int value)
 301 {
 302         struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
 303         unsigned mask = 1 << offset;
 304         int status;
 305
 306         mutex_lock(&mcp->lock);
 307         status = __mcp23s08_set(mcp, mask, value);
 308         if (status == 0) {
 309                 mcp->cache[MCP_IODIR] &= ~mask;
 310                 status = mcp->ops->write(mcp, MCP_IODIR, mcp->cache[MCP_IODIR]);
 311         }
 312         mutex_unlock(&mcp->lock);
 313         return status;
 314 }
 315
 316 /*----------------------------------------------------------------------*/
 317
 318 #ifdef CONFIG_DEBUG_FS
 319
 320 #include <linux/seq_file.h>
 321
 322 /*
 323  * This shows more info than the generic gpio dump code:
 324  * pullups, deglitching, open drain drive.
 325  */
 326 static void mcp23s08_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 327 {
 328         struct mcp23s08 *mcp;
 329         char            bank;
 330         int             t;
 331         unsigned        mask;
 332
 333         mcp = container_of(chip, struct mcp23s08, chip);
 334
 335         /* NOTE: we only handle one bank for now ... */
 336         bank = '0' + ((mcp->addr >> 1) & 0x7);
 337
 338         mutex_lock(&mcp->lock);
 339         t = mcp->ops->read_regs(mcp, 0, mcp->cache, ARRAY_SIZE(mcp->cache));
 340         if (t < 0) {
 341                 seq_printf(s, " I/O ERROR %d\n", t);
 342                 goto done;
 343         }
 344
 345         for (t = 0, mask = 1; t < chip->ngpio; t++, mask <<= 1) {
 346                 const char      *label;
 347
 348                 label = gpiochip_is_requested(chip, t);
 349                 if (!label)
 350                         continue;
 351
 352                 seq_printf(s, " gpio-%-3d P%c.%d (%-12s) %s %s %s",
 353                         chip->base + t, bank, t, label,
 354                         (mcp->cache[MCP_IODIR] & mask) ? "in " : "out",
 355                         (mcp->cache[MCP_GPIO] & mask) ? "hi" : "lo",
 356                         (mcp->cache[MCP_GPPU] & mask) ? "up" : "  ");
 357                 /* NOTE:  ignoring the irq-related registers */
 358                 seq_printf(s, "\n");
 359         }
 360 done:
 361         mutex_unlock(&mcp->lock);
 362 }
 363
 364 #else
 365 #define mcp23s08_dbg_show       NULL
 366 #endif
 367
 368 /*----------------------------------------------------------------------*/
 369
 370 static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
 371                               void *data, unsigned addr,
 372                               unsigned type, unsigned base, unsigned pullups)
 373 {
 374         int status;
 375
 376         mutex_init(&mcp->lock);
 377
 378         mcp->data = data;
 379         mcp->addr = addr;
 380
 381         mcp->chip.direction_input = mcp23s08_direction_input;
 382         mcp->chip.get = mcp23s08_get;
 383         mcp->chip.direction_output = mcp23s08_direction_output;
 384         mcp->chip.set = mcp23s08_set;
 385         mcp->chip.dbg_show = mcp23s08_dbg_show;
 386
 387         switch (type) {
 388 #ifdef CONFIG_SPI_MASTER
 389         case MCP_TYPE_S08:
 390                 mcp->ops = &mcp23s08_ops;
 391                 mcp->chip.ngpio = 8;
 392                 mcp->chip.label = "mcp23s08";
 393                 break;
 394
 395         case MCP_TYPE_S17:
 396                 mcp->ops = &mcp23s17_ops;
 397                 mcp->chip.ngpio = 16;
 398                 mcp->chip.label = "mcp23s17";
 399                 break;
 400 #endif /* CONFIG_SPI_MASTER */
 401
 402 #ifdef CONFIG_I2C
 403         case MCP_TYPE_008:
 404                 mcp->ops = &mcp23008_ops;
 405                 mcp->chip.ngpio = 8;
 406                 mcp->chip.label = "mcp23008";
 407                 break;
 408
 409         case MCP_TYPE_017:
 410                 mcp->ops = &mcp23017_ops;
 411                 mcp->chip.ngpio = 16;
 412                 mcp->chip.label = "mcp23017";
 413                 break;
 414 #endif /* CONFIG_I2C */
 415
 416         default:
 417                 dev_err(dev, "invalid device type (%d)\n", type);
 418                 return -EINVAL;
 419         }
 420
 421         mcp->chip.base = base;
 422         mcp->chip.can_sleep = 1;
 423         mcp->chip.dev = dev;
 424         mcp->chip.owner = THIS_MODULE;
 425
 426         /* verify MCP_IOCON.SEQOP = 0, so sequential reads work,
 427          * and MCP_IOCON.HAEN = 1, so we work with all chips.
 428          */
 429         status = mcp->ops->read(mcp, MCP_IOCON);
 430         if (status < 0)
 431                 goto fail;
 432         if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN)) {
 433                 /* mcp23s17 has IOCON twice, make sure they are in sync */
 434                 status &= ~(IOCON_SEQOP | (IOCON_SEQOP << 8));
 435                 status |= IOCON_HAEN | (IOCON_HAEN << 8);
 436                 status = mcp->ops->write(mcp, MCP_IOCON, status);
 437                 if (status < 0)
 438                         goto fail;
 439         }
 440
 441         /* configure ~100K pullups */
 442         status = mcp->ops->write(mcp, MCP_GPPU, pullups);
 443         if (status < 0)
 444                 goto fail;
 445
 446         status = mcp->ops->read_regs(mcp, 0, mcp->cache, ARRAY_SIZE(mcp->cache));
 447         if (status < 0)
 448                 goto fail;
 449
 450         /* disable inverter on input */
 451         if (mcp->cache[MCP_IPOL] != 0) {
 452                 mcp->cache[MCP_IPOL] = 0;
 453                 status = mcp->ops->write(mcp, MCP_IPOL, 0);
 454                 if (status < 0)
 455                         goto fail;
 456         }
 457
 458         /* disable irqs */
 459         if (mcp->cache[MCP_GPINTEN] != 0) {
 460                 mcp->cache[MCP_GPINTEN] = 0;
 461                 status = mcp->ops->write(mcp, MCP_GPINTEN, 0);
 462                 if (status < 0)
 463                         goto fail;
 464         }
 465
 466         status = gpiochip_add(&mcp->chip);
 467 fail:
 468         if (status < 0)
 469                 dev_dbg(dev, "can't setup chip %d, --> %d\n",
 470                         addr, status);
 471         return status;
 472 }
 473
 474 /*----------------------------------------------------------------------*/
 475
 476 #ifdef CONFIG_I2C
 477
 478 static int __devinit mcp230xx_probe(struct i2c_client *client,
 479                                     const struct i2c_device_id *id)
 480 {
 481         struct mcp23s08_platform_data *pdata;
 482         struct mcp23s08 *mcp;
 483         int status;
 484
 485         pdata = client->dev.platform_data;
 486         if (!pdata || !gpio_is_valid(pdata->base)) {
 487                 dev_dbg(&client->dev, "invalid or missing platform data\n");
 488                 return -EINVAL;
 489         }
 490
 491         mcp = kzalloc(sizeof *mcp, GFP_KERNEL);
 492         if (!mcp)
 493                 return -ENOMEM;
 494
 495         status = mcp23s08_probe_one(mcp, &client->dev, client, client->addr,
 496                                     id->driver_data, pdata->base,
 497                                     pdata->chip[0].pullups);
 498         if (status)
 499                 goto fail;
 500
 501         i2c_set_clientdata(client, mcp);
 502
 503         return 0;
 504
 505 fail:
 506         kfree(mcp);
 507
 508         return status;
 509 }
 510
 511 static int __devexit mcp230xx_remove(struct i2c_client *client)
 512 {
 513         struct mcp23s08 *mcp = i2c_get_clientdata(client);
 514         int status;
 515
 516         status = gpiochip_remove(&mcp->chip);
 517         if (status == 0)
 518                 kfree(mcp);
 519
 520         return status;
 521 }
 522
 523 static const struct i2c_device_id mcp230xx_id[] = {
 524         { "mcp23008", MCP_TYPE_008 },
 525         { "mcp23017", MCP_TYPE_017 },
 526         { },
 527 };
 528 MODULE_DEVICE_TABLE(i2c, mcp230xx_id);
 529
 530 static struct i2c_driver mcp230xx_driver = {
 531         .driver = {
 532                 .name   = "mcp230xx",
 533                 .owner  = THIS_MODULE,
 534         },
 535         .probe          = mcp230xx_probe,
 536         .remove         = __devexit_p(mcp230xx_remove),
 537         .id_table       = mcp230xx_id,
 538 };
 539
 540 static int __init mcp23s08_i2c_init(void)
 541 {
 542         return i2c_add_driver(&mcp230xx_driver);
 543 }
 544
 545 static void mcp23s08_i2c_exit(void)
 546 {
 547         i2c_del_driver(&mcp230xx_driver);
 548 }
 549
 550 #else
 551
 552 static int __init mcp23s08_i2c_init(void) { return 0; }
 553 static void mcp23s08_i2c_exit(void) { }
 554
 555 #endif /* CONFIG_I2C */
 556
 557 /*----------------------------------------------------------------------*/
 558
 559 #ifdef CONFIG_SPI_MASTER
 560
 561 static int mcp23s08_probe(struct spi_device *spi)
 562 {
 563         struct mcp23s08_platform_data   *pdata;
 564         unsigned                        addr;
 565         unsigned                        chips = 0;
 566         struct mcp23s08_driver_data     *data;
 567         int                             status, type;
 568         unsigned                        base;
 569
 570         type = spi_get_device_id(spi)->driver_data;
 571
 572         pdata = spi->dev.platform_data;
 573         if (!pdata || !gpio_is_valid(pdata->base)) {
 574                 dev_dbg(&spi->dev, "invalid or missing platform data\n");
 575                 return -EINVAL;
 576         }
 577
 578         for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
 579                 if (!pdata->chip[addr].is_present)
 580                         continue;
 581                 chips++;
 582                 if ((type == MCP_TYPE_S08) && (addr > 3)) {
 583                         dev_err(&spi->dev,
 584                                 "mcp23s08 only supports address 0..3\n");
 585                         return -EINVAL;
 586                 }
 587         }
 588         if (!chips)
 589                 return -ENODEV;
 590
 591         data = kzalloc(sizeof *data + chips * sizeof(struct mcp23s08),
 592                         GFP_KERNEL);
 593         if (!data)
 594                 return -ENOMEM;
 595         spi_set_drvdata(spi, data);
 596
 597         base = pdata->base;
 598         for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
 599                 if (!pdata->chip[addr].is_present)
 600                         continue;
 601                 chips--;
 602                 data->mcp[addr] = &data->chip[chips];
 603                 status = mcp23s08_probe_one(data->mcp[addr], &spi->dev, spi,
 604                                             0x40 | (addr << 1), type, base,
 605                                             pdata->chip[addr].pullups);
 606                 if (status < 0)
 607                         goto fail;
 608
 609                 base += (type == MCP_TYPE_S17) ? 16 : 8;
 610         }
 611         data->ngpio = base - pdata->base;
 612
 613         /* NOTE:  these chips have a relatively sane IRQ framework, with
 614          * per-signal masking and level/edge triggering.  It's not yet
 615          * handled here...
 616          */
 617
 618         return 0;
 619
 620 fail:
 621         for (addr = 0; addr < ARRAY_SIZE(data->mcp); addr++) {
 622                 int tmp;
 623
 624                 if (!data->mcp[addr])
 625                         continue;
 626                 tmp = gpiochip_remove(&data->mcp[addr]->chip);
 627                 if (tmp < 0)
 628                         dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
 629         }
 630         kfree(data);
 631         return status;
 632 }
 633
 634 static int mcp23s08_remove(struct spi_device *spi)
 635 {
 636         struct mcp23s08_driver_data     *data = spi_get_drvdata(spi);
 637         unsigned                        addr;
 638         int                             status = 0;
 639
 640         for (addr = 0; addr < ARRAY_SIZE(data->mcp); addr++) {
 641                 int tmp;
 642
 643                 if (!data->mcp[addr])
 644                         continue;
 645
 646                 tmp = gpiochip_remove(&data->mcp[addr]->chip);
 647                 if (tmp < 0) {
 648                         dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
 649                         status = tmp;
 650                 }
 651         }
 652         if (status == 0)
 653                 kfree(data);
 654         return status;
 655 }
 656
 657 static const struct spi_device_id mcp23s08_ids[] = {
 658         { "mcp23s08", MCP_TYPE_S08 },
 659         { "mcp23s17", MCP_TYPE_S17 },
 660         { },
 661 };
 662 MODULE_DEVICE_TABLE(spi, mcp23s08_ids);
 663
 664 static struct spi_driver mcp23s08_driver = {
 665         .probe          = mcp23s08_probe,
 666         .remove         = mcp23s08_remove,
 667         .id_table       = mcp23s08_ids,
 668         .driver = {
 669                 .name   = "mcp23s08",
 670                 .owner  = THIS_MODULE,
 671         },
 672 };
 673
 674 static int __init mcp23s08_spi_init(void)
 675 {
 676         return spi_register_driver(&mcp23s08_driver);
 677 }
 678
 679 static void mcp23s08_spi_exit(void)
 680 {
 681         spi_unregister_driver(&mcp23s08_driver);
 682 }
 683
 684 #else
 685
 686 static int __init mcp23s08_spi_init(void) { return 0; }
 687 static void mcp23s08_spi_exit(void) { }
 688
 689 #endif /* CONFIG_SPI_MASTER */
 690
 691 /*----------------------------------------------------------------------*/
 692
 693 static int __init mcp23s08_init(void)
 694 {
 695         int ret;
 696
 697         ret = mcp23s08_spi_init();
 698         if (ret)
 699                 goto spi_fail;
 700
 701         ret = mcp23s08_i2c_init();
 702         if (ret)
 703                 goto i2c_fail;
 704
 705         return 0;
 706
 707  i2c_fail:
 708         mcp23s08_spi_exit();
 709  spi_fail:
 710         return ret;
 711 }
 712 /* register after spi/i2c postcore initcall and before
 713  * subsys initcalls that may rely on these GPIOs
 714  */
 715 subsys_initcall(mcp23s08_init);
 716
 717 static void __exit mcp23s08_exit(void)
 718 {
 719         mcp23s08_spi_exit();
 720         mcp23s08_i2c_exit();
 721 }
 722 module_exit(mcp23s08_exit);
 723
 724 MODULE_LICENSE("GPL");