drivers/gpio/gpio-max732x.c

   1 /*
   2  *  MAX732x I2C Port Expander with 8/16 I/O
   3  *
   4  *  Copyright (C) 2007 Marvell International Ltd.
   5  *  Copyright (C) 2008 Jack Ren <jack.ren@marvell.com>
   6  *  Copyright (C) 2008 Eric Miao <eric.miao@marvell.com>
   7  *  Copyright (C) 2015 Linus Walleij <linus.walleij@linaro.org>
   8  *
   9  *  Derived from drivers/gpio/pca953x.c
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License as published by
  13  *  the Free Software Foundation; version 2 of the License.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/slab.h>
  19 #include <linux/string.h>
  20 #include <linux/gpio/driver.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/i2c.h>
  23 #include <linux/i2c/max732x.h>
  24 #include <linux/of.h>
  25
  26
  27 /*
  28  * Each port of MAX732x (including MAX7319) falls into one of the
  29  * following three types:
  30  *
  31  *   - Push Pull Output
  32  *   - Input
  33  *   - Open Drain I/O
  34  *
  35  * designated by 'O', 'I' and 'P' individually according to MAXIM's
  36  * datasheets. 'I' and 'P' ports are interrupt capables, some with
  37  * a dedicated interrupt mask.
  38  *
  39  * There are two groups of I/O ports, each group usually includes
  40  * up to 8 I/O ports, and is accessed by a specific I2C address:
  41  *
  42  *   - Group A : by I2C address 0b'110xxxx
  43  *   - Group B : by I2C address 0b'101xxxx
  44  *
  45  * where 'xxxx' is decided by the connections of pin AD2/AD0.  The
  46  * address used also affects the initial state of output signals.
  47  *
  48  * Within each group of ports, there are five known combinations of
  49  * I/O ports: 4I4O, 4P4O, 8I, 8P, 8O, see the definitions below for
  50  * the detailed organization of these ports. Only Goup A is interrupt
  51  * capable.
  52  *
  53  * GPIO numbers start from 'gpio_base + 0' to 'gpio_base + 8/16',
  54  * and GPIOs from GROUP_A are numbered before those from GROUP_B
  55  * (if there are two groups).
  56  *
  57  * NOTE: MAX7328/MAX7329 are drop-in replacements for PCF8574/a, so
  58  * they are not supported by this driver.
  59  */
  60
  61 #define PORT_NONE       0x0     /* '/' No Port */
  62 #define PORT_OUTPUT     0x1     /* 'O' Push-Pull, Output Only */
  63 #define PORT_INPUT      0x2     /* 'I' Input Only */
  64 #define PORT_OPENDRAIN  0x3     /* 'P' Open-Drain, I/O */
  65
  66 #define IO_4I4O         0x5AA5  /* O7 O6 I5 I4 I3 I2 O1 O0 */
  67 #define IO_4P4O         0x5FF5  /* O7 O6 P5 P4 P3 P2 O1 O0 */
  68 #define IO_8I           0xAAAA  /* I7 I6 I5 I4 I3 I2 I1 I0 */
  69 #define IO_8P           0xFFFF  /* P7 P6 P5 P4 P3 P2 P1 P0 */
  70 #define IO_8O           0x5555  /* O7 O6 O5 O4 O3 O2 O1 O0 */
  71
  72 #define GROUP_A(x)      ((x) & 0xffff)  /* I2C Addr: 0b'110xxxx */
  73 #define GROUP_B(x)      ((x) << 16)     /* I2C Addr: 0b'101xxxx */
  74
  75 #define INT_NONE        0x0     /* No interrupt capability */
  76 #define INT_NO_MASK     0x1     /* Has interrupts, no mask */
  77 #define INT_INDEP_MASK  0x2     /* Has interrupts, independent mask */
  78 #define INT_MERGED_MASK 0x3     /* Has interrupts, merged mask */
  79
  80 #define INT_CAPS(x)     (((uint64_t)(x)) << 32)
  81
  82 enum {
  83         MAX7319,
  84         MAX7320,
  85         MAX7321,
  86         MAX7322,
  87         MAX7323,
  88         MAX7324,
  89         MAX7325,
  90         MAX7326,
  91         MAX7327,
  92 };
  93
  94 static uint64_t max732x_features[] = {
  95         [MAX7319] = GROUP_A(IO_8I) | INT_CAPS(INT_MERGED_MASK),
  96         [MAX7320] = GROUP_B(IO_8O),
  97         [MAX7321] = GROUP_A(IO_8P) | INT_CAPS(INT_NO_MASK),
  98         [MAX7322] = GROUP_A(IO_4I4O) | INT_CAPS(INT_MERGED_MASK),
  99         [MAX7323] = GROUP_A(IO_4P4O) | INT_CAPS(INT_INDEP_MASK),
 100         [MAX7324] = GROUP_A(IO_8I) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK),
 101         [MAX7325] = GROUP_A(IO_8P) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK),
 102         [MAX7326] = GROUP_A(IO_4I4O) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK),
 103         [MAX7327] = GROUP_A(IO_4P4O) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK),
 104 };
 105
 106 static const struct i2c_device_id max732x_id[] = {
 107         { "max7319", MAX7319 },
 108         { "max7320", MAX7320 },
 109         { "max7321", MAX7321 },
 110         { "max7322", MAX7322 },
 111         { "max7323", MAX7323 },
 112         { "max7324", MAX7324 },
 113         { "max7325", MAX7325 },
 114         { "max7326", MAX7326 },
 115         { "max7327", MAX7327 },
 116         { },
 117 };
 118 MODULE_DEVICE_TABLE(i2c, max732x_id);
 119
 120 #ifdef CONFIG_OF
 121 static const struct of_device_id max732x_of_table[] = {
 122         { .compatible = "maxim,max7319" },
 123         { .compatible = "maxim,max7320" },
 124         { .compatible = "maxim,max7321" },
 125         { .compatible = "maxim,max7322" },
 126         { .compatible = "maxim,max7323" },
 127         { .compatible = "maxim,max7324" },
 128         { .compatible = "maxim,max7325" },
 129         { .compatible = "maxim,max7326" },
 130         { .compatible = "maxim,max7327" },
 131         { }
 132 };
 133 MODULE_DEVICE_TABLE(of, max732x_of_table);
 134 #endif
 135
 136 struct max732x_chip {
 137         struct gpio_chip gpio_chip;
 138
 139         struct i2c_client *client;      /* "main" client */
 140         struct i2c_client *client_dummy;
 141         struct i2c_client *client_group_a;
 142         struct i2c_client *client_group_b;
 143
 144         unsigned int    mask_group_a;
 145         unsigned int    dir_input;
 146         unsigned int    dir_output;
 147
 148         struct mutex    lock;
 149         uint8_t         reg_out[2];
 150
 151 #ifdef CONFIG_GPIO_MAX732X_IRQ
 152         struct mutex            irq_lock;
 153         uint8_t                 irq_mask;
 154         uint8_t                 irq_mask_cur;
 155         uint8_t                 irq_trig_raise;
 156         uint8_t                 irq_trig_fall;
 157         uint8_t                 irq_features;
 158 #endif
 159 };
 160
 161 static inline struct max732x_chip *to_max732x(struct gpio_chip *gc)
 162 {
 163         return container_of(gc, struct max732x_chip, gpio_chip);
 164 }
 165
 166 static int max732x_writeb(struct max732x_chip *chip, int group_a, uint8_t val)
 167 {
 168         struct i2c_client *client;
 169         int ret;
 170
 171         client = group_a ? chip->client_group_a : chip->client_group_b;
 172         ret = i2c_smbus_write_byte(client, val);
 173         if (ret < 0) {
 174                 dev_err(&client->dev, "failed writing\n");
 175                 return ret;
 176         }
 177
 178         return 0;
 179 }
 180
 181 static int max732x_readb(struct max732x_chip *chip, int group_a, uint8_t *val)
 182 {
 183         struct i2c_client *client;
 184         int ret;
 185
 186         client = group_a ? chip->client_group_a : chip->client_group_b;
 187         ret = i2c_smbus_read_byte(client);
 188         if (ret < 0) {
 189                 dev_err(&client->dev, "failed reading\n");
 190                 return ret;
 191         }
 192
 193         *val = (uint8_t)ret;
 194         return 0;
 195 }
 196
 197 static inline int is_group_a(struct max732x_chip *chip, unsigned off)
 198 {
 199         return (1u << off) & chip->mask_group_a;
 200 }
 201
 202 static int max732x_gpio_get_value(struct gpio_chip *gc, unsigned off)
 203 {
 204         struct max732x_chip *chip = to_max732x(gc);
 205         uint8_t reg_val;
 206         int ret;
 207
 208         ret = max732x_readb(chip, is_group_a(chip, off), &reg_val);
 209         if (ret < 0)
 210                 return 0;
 211
 212         return reg_val & (1u << (off & 0x7));
 213 }
 214
 215 static void max732x_gpio_set_mask(struct gpio_chip *gc, unsigned off, int mask,
 216                                   int val)
 217 {
 218         struct max732x_chip *chip = to_max732x(gc);
 219         uint8_t reg_out;
 220         int ret;
 221
 222         mutex_lock(&chip->lock);
 223
 224         reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0];
 225         reg_out = (reg_out & ~mask) | (val & mask);
 226
 227         ret = max732x_writeb(chip, is_group_a(chip, off), reg_out);
 228         if (ret < 0)
 229                 goto out;
 230
 231         /* update the shadow register then */
 232         if (off > 7)
 233                 chip->reg_out[1] = reg_out;
 234         else
 235                 chip->reg_out[0] = reg_out;
 236 out:
 237         mutex_unlock(&chip->lock);
 238 }
 239
 240 static void max732x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
 241 {
 242         unsigned base = off & ~0x7;
 243         uint8_t mask = 1u << (off & 0x7);
 244
 245         max732x_gpio_set_mask(gc, base, mask, val << (off & 0x7));
 246 }
 247
 248 static void max732x_gpio_set_multiple(struct gpio_chip *gc,
 249                                       unsigned long *mask, unsigned long *bits)
 250 {
 251         unsigned mask_lo = mask[0] & 0xff;
 252         unsigned mask_hi = (mask[0] >> 8) & 0xff;
 253
 254         if (mask_lo)
 255                 max732x_gpio_set_mask(gc, 0, mask_lo, bits[0] & 0xff);
 256         if (mask_hi)
 257                 max732x_gpio_set_mask(gc, 8, mask_hi, (bits[0] >> 8) & 0xff);
 258 }
 259
 260 static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
 261 {
 262         struct max732x_chip *chip = to_max732x(gc);
 263         unsigned int mask = 1u << off;
 264
 265         if ((mask & chip->dir_input) == 0) {
 266                 dev_dbg(&chip->client->dev, "%s port %d is output only\n",
 267                         chip->client->name, off);
 268                 return -EACCES;
 269         }
 270
 271         /*
 272          * Open-drain pins must be set to high impedance (which is
 273          * equivalent to output-high) to be turned into an input.
 274          */
 275         if ((mask & chip->dir_output))
 276                 max732x_gpio_set_value(gc, off, 1);
 277
 278         return 0;
 279 }
 280
 281 static int max732x_gpio_direction_output(struct gpio_chip *gc,
 282                 unsigned off, int val)
 283 {
 284         struct max732x_chip *chip = to_max732x(gc);
 285         unsigned int mask = 1u << off;
 286
 287         if ((mask & chip->dir_output) == 0) {
 288                 dev_dbg(&chip->client->dev, "%s port %d is input only\n",
 289                         chip->client->name, off);
 290                 return -EACCES;
 291         }
 292
 293         max732x_gpio_set_value(gc, off, val);
 294         return 0;
 295 }
 296
 297 #ifdef CONFIG_GPIO_MAX732X_IRQ
 298 static int max732x_writew(struct max732x_chip *chip, uint16_t val)
 299 {
 300         int ret;
 301
 302         val = cpu_to_le16(val);
 303
 304         ret = i2c_master_send(chip->client_group_a, (char *)&val, 2);
 305         if (ret < 0) {
 306                 dev_err(&chip->client_group_a->dev, "failed writing\n");
 307                 return ret;
 308         }
 309
 310         return 0;
 311 }
 312
 313 static int max732x_readw(struct max732x_chip *chip, uint16_t *val)
 314 {
 315         int ret;
 316
 317         ret = i2c_master_recv(chip->client_group_a, (char *)val, 2);
 318         if (ret < 0) {
 319                 dev_err(&chip->client_group_a->dev, "failed reading\n");
 320                 return ret;
 321         }
 322
 323         *val = le16_to_cpu(*val);
 324         return 0;
 325 }
 326
 327 static void max732x_irq_update_mask(struct max732x_chip *chip)
 328 {
 329         uint16_t msg;
 330
 331         if (chip->irq_mask == chip->irq_mask_cur)
 332                 return;
 333
 334         chip->irq_mask = chip->irq_mask_cur;
 335
 336         if (chip->irq_features == INT_NO_MASK)
 337                 return;
 338
 339         mutex_lock(&chip->lock);
 340
 341         switch (chip->irq_features) {
 342         case INT_INDEP_MASK:
 343                 msg = (chip->irq_mask << 8) | chip->reg_out[0];
 344                 max732x_writew(chip, msg);
 345                 break;
 346
 347         case INT_MERGED_MASK:
 348                 msg = chip->irq_mask | chip->reg_out[0];
 349                 max732x_writeb(chip, 1, (uint8_t)msg);
 350                 break;
 351         }
 352
 353         mutex_unlock(&chip->lock);
 354 }
 355
 356 static void max732x_irq_mask(struct irq_data *d)
 357 {
 358         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 359         struct max732x_chip *chip = to_max732x(gc);
 360
 361         chip->irq_mask_cur &= ~(1 << d->hwirq);
 362 }
 363
 364 static void max732x_irq_unmask(struct irq_data *d)
 365 {
 366         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 367         struct max732x_chip *chip = to_max732x(gc);
 368
 369         chip->irq_mask_cur |= 1 << d->hwirq;
 370 }
 371
 372 static void max732x_irq_bus_lock(struct irq_data *d)
 373 {
 374         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 375         struct max732x_chip *chip = to_max732x(gc);
 376
 377         mutex_lock(&chip->irq_lock);
 378         chip->irq_mask_cur = chip->irq_mask;
 379 }
 380
 381 static void max732x_irq_bus_sync_unlock(struct irq_data *d)
 382 {
 383         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 384         struct max732x_chip *chip = to_max732x(gc);
 385         uint16_t new_irqs;
 386         uint16_t level;
 387
 388         max732x_irq_update_mask(chip);
 389
 390         new_irqs = chip->irq_trig_fall | chip->irq_trig_raise;
 391         while (new_irqs) {
 392                 level = __ffs(new_irqs);
 393                 max732x_gpio_direction_input(&chip->gpio_chip, level);
 394                 new_irqs &= ~(1 << level);
 395         }
 396
 397         mutex_unlock(&chip->irq_lock);
 398 }
 399
 400 static int max732x_irq_set_type(struct irq_data *d, unsigned int type)
 401 {
 402         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 403         struct max732x_chip *chip = to_max732x(gc);
 404         uint16_t off = d->hwirq;
 405         uint16_t mask = 1 << off;
 406
 407         if (!(mask & chip->dir_input)) {
 408                 dev_dbg(&chip->client->dev, "%s port %d is output only\n",
 409                         chip->client->name, off);
 410                 return -EACCES;
 411         }
 412
 413         if (!(type & IRQ_TYPE_EDGE_BOTH)) {
 414                 dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
 415                         d->irq, type);
 416                 return -EINVAL;
 417         }
 418
 419         if (type & IRQ_TYPE_EDGE_FALLING)
 420                 chip->irq_trig_fall |= mask;
 421         else
 422                 chip->irq_trig_fall &= ~mask;
 423
 424         if (type & IRQ_TYPE_EDGE_RISING)
 425                 chip->irq_trig_raise |= mask;
 426         else
 427                 chip->irq_trig_raise &= ~mask;
 428
 429         return 0;
 430 }
 431
 432 static struct irq_chip max732x_irq_chip = {
 433         .name                   = "max732x",
 434         .irq_mask               = max732x_irq_mask,
 435         .irq_unmask             = max732x_irq_unmask,
 436         .irq_bus_lock           = max732x_irq_bus_lock,
 437         .irq_bus_sync_unlock    = max732x_irq_bus_sync_unlock,
 438         .irq_set_type           = max732x_irq_set_type,
 439 };
 440
 441 static uint8_t max732x_irq_pending(struct max732x_chip *chip)
 442 {
 443         uint8_t cur_stat;
 444         uint8_t old_stat;
 445         uint8_t trigger;
 446         uint8_t pending;
 447         uint16_t status;
 448         int ret;
 449
 450         ret = max732x_readw(chip, &status);
 451         if (ret)
 452                 return 0;
 453
 454         trigger = status >> 8;
 455         trigger &= chip->irq_mask;
 456
 457         if (!trigger)
 458                 return 0;
 459
 460         cur_stat = status & 0xFF;
 461         cur_stat &= chip->irq_mask;
 462
 463         old_stat = cur_stat ^ trigger;
 464
 465         pending = (old_stat & chip->irq_trig_fall) |
 466                   (cur_stat & chip->irq_trig_raise);
 467         pending &= trigger;
 468
 469         return pending;
 470 }
 471
 472 static irqreturn_t max732x_irq_handler(int irq, void *devid)
 473 {
 474         struct max732x_chip *chip = devid;
 475         uint8_t pending;
 476         uint8_t level;
 477
 478         pending = max732x_irq_pending(chip);
 479
 480         if (!pending)
 481                 return IRQ_HANDLED;
 482
 483         do {
 484                 level = __ffs(pending);
 485                 handle_nested_irq(irq_find_mapping(chip->gpio_chip.irqdomain,
 486                                                    level));
 487
 488                 pending &= ~(1 << level);
 489         } while (pending);
 490
 491         return IRQ_HANDLED;
 492 }
 493
 494 static int max732x_irq_setup(struct max732x_chip *chip,
 495                              const struct i2c_device_id *id)
 496 {
 497         struct i2c_client *client = chip->client;
 498         struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
 499         int has_irq = max732x_features[id->driver_data] >> 32;
 500         int irq_base = 0;
 501         int ret;
 502
 503         if (((pdata && pdata->irq_base) || client->irq)
 504                         && has_irq != INT_NONE) {
 505                 if (pdata)
 506                         irq_base = pdata->irq_base;
 507                 chip->irq_features = has_irq;
 508                 mutex_init(&chip->irq_lock);
 509
 510                 ret = devm_request_threaded_irq(&client->dev,
 511                                         client->irq,
 512                                         NULL,
 513                                         max732x_irq_handler,
 514                                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 515                                         dev_name(&client->dev), chip);
 516                 if (ret) {
 517                         dev_err(&client->dev, "failed to request irq %d\n",
 518                                 client->irq);
 519                         return ret;
 520                 }
 521                 ret =  gpiochip_irqchip_add(&chip->gpio_chip,
 522                                             &max732x_irq_chip,
 523                                             irq_base,
 524                                             handle_edge_irq,
 525                                             IRQ_TYPE_NONE);
 526                 if (ret) {
 527                         dev_err(&client->dev,
 528                                 "could not connect irqchip to gpiochip\n");
 529                         return ret;
 530                 }
 531                 gpiochip_set_chained_irqchip(&chip->gpio_chip,
 532                                              &max732x_irq_chip,
 533                                              client->irq,
 534                                              NULL);
 535         }
 536
 537         return 0;
 538 }
 539
 540 #else /* CONFIG_GPIO_MAX732X_IRQ */
 541 static int max732x_irq_setup(struct max732x_chip *chip,
 542                              const struct i2c_device_id *id)
 543 {
 544         struct i2c_client *client = chip->client;
 545         struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
 546         int has_irq = max732x_features[id->driver_data] >> 32;
 547
 548         if (((pdata && pdata->irq_base) || client->irq) && has_irq != INT_NONE)
 549                 dev_warn(&client->dev, "interrupt support not compiled in\n");
 550
 551         return 0;
 552 }
 553 #endif
 554
 555 static int max732x_setup_gpio(struct max732x_chip *chip,
 556                                         const struct i2c_device_id *id,
 557                                         unsigned gpio_start)
 558 {
 559         struct gpio_chip *gc = &chip->gpio_chip;
 560         uint32_t id_data = (uint32_t)max732x_features[id->driver_data];
 561         int i, port = 0;
 562
 563         for (i = 0; i < 16; i++, id_data >>= 2) {
 564                 unsigned int mask = 1 << port;
 565
 566                 switch (id_data & 0x3) {
 567                 case PORT_OUTPUT:
 568                         chip->dir_output |= mask;
 569                         break;
 570                 case PORT_INPUT:
 571                         chip->dir_input |= mask;
 572                         break;
 573                 case PORT_OPENDRAIN:
 574                         chip->dir_output |= mask;
 575                         chip->dir_input |= mask;
 576                         break;
 577                 default:
 578                         continue;
 579                 }
 580
 581                 if (i < 8)
 582                         chip->mask_group_a |= mask;
 583                 port++;
 584         }
 585
 586         if (chip->dir_input)
 587                 gc->direction_input = max732x_gpio_direction_input;
 588         if (chip->dir_output) {
 589                 gc->direction_output = max732x_gpio_direction_output;
 590                 gc->set = max732x_gpio_set_value;
 591                 gc->set_multiple = max732x_gpio_set_multiple;
 592         }
 593         gc->get = max732x_gpio_get_value;
 594         gc->can_sleep = true;
 595
 596         gc->base = gpio_start;
 597         gc->ngpio = port;
 598         gc->label = chip->client->name;
 599         gc->owner = THIS_MODULE;
 600
 601         return port;
 602 }
 603
 604 static struct max732x_platform_data *of_gpio_max732x(struct device *dev)
 605 {
 606         struct max732x_platform_data *pdata;
 607
 608         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 609         if (!pdata)
 610                 return NULL;
 611
 612         pdata->gpio_base = -1;
 613
 614         return pdata;
 615 }
 616
 617 static int max732x_probe(struct i2c_client *client,
 618                                    const struct i2c_device_id *id)
 619 {
 620         struct max732x_platform_data *pdata;
 621         struct device_node *node;
 622         struct max732x_chip *chip;
 623         struct i2c_client *c;
 624         uint16_t addr_a, addr_b;
 625         int ret, nr_port;
 626
 627         pdata = dev_get_platdata(&client->dev);
 628         node = client->dev.of_node;
 629
 630         if (!pdata && node)
 631                 pdata = of_gpio_max732x(&client->dev);
 632
 633         if (!pdata) {
 634                 dev_dbg(&client->dev, "no platform data\n");
 635                 return -EINVAL;
 636         }
 637
 638         chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 639         if (chip == NULL)
 640                 return -ENOMEM;
 641         chip->client = client;
 642
 643         nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base);
 644         chip->gpio_chip.dev = &client->dev;
 645
 646         addr_a = (client->addr & 0x0f) | 0x60;
 647         addr_b = (client->addr & 0x0f) | 0x50;
 648
 649         switch (client->addr & 0x70) {
 650         case 0x60:
 651                 chip->client_group_a = client;
 652                 if (nr_port > 8) {
 653                         c = i2c_new_dummy(client->adapter, addr_b);
 654                         chip->client_group_b = chip->client_dummy = c;
 655                 }
 656                 break;
 657         case 0x50:
 658                 chip->client_group_b = client;
 659                 if (nr_port > 8) {
 660                         c = i2c_new_dummy(client->adapter, addr_a);
 661                         chip->client_group_a = chip->client_dummy = c;
 662                 }
 663                 break;
 664         default:
 665                 dev_err(&client->dev, "invalid I2C address specified %02x\n",
 666                                 client->addr);
 667                 ret = -EINVAL;
 668                 goto out_failed;
 669         }
 670
 671         if (nr_port > 8 && !chip->client_dummy) {
 672                 dev_err(&client->dev,
 673                         "Failed to allocate second group I2C device\n");
 674                 ret = -ENODEV;
 675                 goto out_failed;
 676         }
 677
 678         mutex_init(&chip->lock);
 679
 680         max732x_readb(chip, is_group_a(chip, 0), &chip->reg_out[0]);
 681         if (nr_port > 8)
 682                 max732x_readb(chip, is_group_a(chip, 8), &chip->reg_out[1]);
 683
 684         ret = gpiochip_add(&chip->gpio_chip);
 685         if (ret)
 686                 goto out_failed;
 687
 688         ret = max732x_irq_setup(chip, id);
 689         if (ret) {
 690                 gpiochip_remove(&chip->gpio_chip);
 691                 goto out_failed;
 692         }
 693
 694         if (pdata && pdata->setup) {
 695                 ret = pdata->setup(client, chip->gpio_chip.base,
 696                                 chip->gpio_chip.ngpio, pdata->context);
 697                 if (ret < 0)
 698                         dev_warn(&client->dev, "setup failed, %d\n", ret);
 699         }
 700
 701         i2c_set_clientdata(client, chip);
 702         return 0;
 703
 704 out_failed:
 705         if (chip->client_dummy)
 706                 i2c_unregister_device(chip->client_dummy);
 707         return ret;
 708 }
 709
 710 static int max732x_remove(struct i2c_client *client)
 711 {
 712         struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
 713         struct max732x_chip *chip = i2c_get_clientdata(client);
 714
 715         if (pdata && pdata->teardown) {
 716                 int ret;
 717
 718                 ret = pdata->teardown(client, chip->gpio_chip.base,
 719                                 chip->gpio_chip.ngpio, pdata->context);
 720                 if (ret < 0) {
 721                         dev_err(&client->dev, "%s failed, %d\n",
 722                                         "teardown", ret);
 723                         return ret;
 724                 }
 725         }
 726
 727         gpiochip_remove(&chip->gpio_chip);
 728
 729         /* unregister any dummy i2c_client */
 730         if (chip->client_dummy)
 731                 i2c_unregister_device(chip->client_dummy);
 732
 733         return 0;
 734 }
 735
 736 static struct i2c_driver max732x_driver = {
 737         .driver = {
 738                 .name           = "max732x",
 739                 .owner          = THIS_MODULE,
 740                 .of_match_table = of_match_ptr(max732x_of_table),
 741         },
 742         .probe          = max732x_probe,
 743         .remove         = max732x_remove,
 744         .id_table       = max732x_id,
 745 };
 746
 747 static int __init max732x_init(void)
 748 {
 749         return i2c_add_driver(&max732x_driver);
 750 }
 751 /* register after i2c postcore initcall and before
 752  * subsys initcalls that may rely on these GPIOs
 753  */
 754 subsys_initcall(max732x_init);
 755
 756 static void __exit max732x_exit(void)
 757 {
 758         i2c_del_driver(&max732x_driver);
 759 }
 760 module_exit(max732x_exit);
 761
 762 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
 763 MODULE_DESCRIPTION("GPIO expander driver for MAX732X");
 764 MODULE_LICENSE("GPL");