drivers/gpio/gpio-max732x.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  MAX732x I2C Port Expander with 8/16 I/O
   4  *
   5  *  Copyright (C) 2007 Marvell International Ltd.
   6  *  Copyright (C) 2008 Jack Ren <jack.ren@marvell.com>
   7  *  Copyright (C) 2008 Eric Miao <eric.miao@marvell.com>
   8  *  Copyright (C) 2015 Linus Walleij <linus.walleij@linaro.org>
   9  *
  10  *  Derived from drivers/gpio/pca953x.c
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/slab.h>
  16 #include <linux/string.h>
  17 #include <linux/gpio/driver.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/i2c.h>
  20 #include <linux/platform_data/max732x.h>
  21 #include <linux/of.h>
  22
  23
  24 /*
  25  * Each port of MAX732x (including MAX7319) falls into one of the
  26  * following three types:
  27  *
  28  *   - Push Pull Output
  29  *   - Input
  30  *   - Open Drain I/O
  31  *
  32  * designated by 'O', 'I' and 'P' individually according to MAXIM's
  33  * datasheets. 'I' and 'P' ports are interrupt capables, some with
  34  * a dedicated interrupt mask.
  35  *
  36  * There are two groups of I/O ports, each group usually includes
  37  * up to 8 I/O ports, and is accessed by a specific I2C address:
  38  *
  39  *   - Group A : by I2C address 0b'110xxxx
  40  *   - Group B : by I2C address 0b'101xxxx
  41  *
  42  * where 'xxxx' is decided by the connections of pin AD2/AD0.  The
  43  * address used also affects the initial state of output signals.
  44  *
  45  * Within each group of ports, there are five known combinations of
  46  * I/O ports: 4I4O, 4P4O, 8I, 8P, 8O, see the definitions below for
  47  * the detailed organization of these ports. Only Goup A is interrupt
  48  * capable.
  49  *
  50  * GPIO numbers start from 'gpio_base + 0' to 'gpio_base + 8/16',
  51  * and GPIOs from GROUP_A are numbered before those from GROUP_B
  52  * (if there are two groups).
  53  *
  54  * NOTE: MAX7328/MAX7329 are drop-in replacements for PCF8574/a, so
  55  * they are not supported by this driver.
  56  */
  57
  58 #define PORT_NONE       0x0     /* '/' No Port */
  59 #define PORT_OUTPUT     0x1     /* 'O' Push-Pull, Output Only */
  60 #define PORT_INPUT      0x2     /* 'I' Input Only */
  61 #define PORT_OPENDRAIN  0x3     /* 'P' Open-Drain, I/O */
  62
  63 #define IO_4I4O         0x5AA5  /* O7 O6 I5 I4 I3 I2 O1 O0 */
  64 #define IO_4P4O         0x5FF5  /* O7 O6 P5 P4 P3 P2 O1 O0 */
  65 #define IO_8I           0xAAAA  /* I7 I6 I5 I4 I3 I2 I1 I0 */
  66 #define IO_8P           0xFFFF  /* P7 P6 P5 P4 P3 P2 P1 P0 */
  67 #define IO_8O           0x5555  /* O7 O6 O5 O4 O3 O2 O1 O0 */
  68
  69 #define GROUP_A(x)      ((x) & 0xffff)  /* I2C Addr: 0b'110xxxx */
  70 #define GROUP_B(x)      ((x) << 16)     /* I2C Addr: 0b'101xxxx */
  71
  72 #define INT_NONE        0x0     /* No interrupt capability */
  73 #define INT_NO_MASK     0x1     /* Has interrupts, no mask */
  74 #define INT_INDEP_MASK  0x2     /* Has interrupts, independent mask */
  75 #define INT_MERGED_MASK 0x3     /* Has interrupts, merged mask */
  76
  77 #define INT_CAPS(x)     (((uint64_t)(x)) << 32)
  78
  79 enum {
  80         MAX7319,
  81         MAX7320,
  82         MAX7321,
  83         MAX7322,
  84         MAX7323,
  85         MAX7324,
  86         MAX7325,
  87         MAX7326,
  88         MAX7327,
  89 };
  90
  91 static uint64_t max732x_features[] = {
  92         [MAX7319] = GROUP_A(IO_8I) | INT_CAPS(INT_MERGED_MASK),
  93         [MAX7320] = GROUP_B(IO_8O),
  94         [MAX7321] = GROUP_A(IO_8P) | INT_CAPS(INT_NO_MASK),
  95         [MAX7322] = GROUP_A(IO_4I4O) | INT_CAPS(INT_MERGED_MASK),
  96         [MAX7323] = GROUP_A(IO_4P4O) | INT_CAPS(INT_INDEP_MASK),
  97         [MAX7324] = GROUP_A(IO_8I) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK),
  98         [MAX7325] = GROUP_A(IO_8P) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK),
  99         [MAX7326] = GROUP_A(IO_4I4O) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK),
 100         [MAX7327] = GROUP_A(IO_4P4O) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK),
 101 };
 102
 103 static const struct i2c_device_id max732x_id[] = {
 104         { "max7319", MAX7319 },
 105         { "max7320", MAX7320 },
 106         { "max7321", MAX7321 },
 107         { "max7322", MAX7322 },
 108         { "max7323", MAX7323 },
 109         { "max7324", MAX7324 },
 110         { "max7325", MAX7325 },
 111         { "max7326", MAX7326 },
 112         { "max7327", MAX7327 },
 113         { },
 114 };
 115 MODULE_DEVICE_TABLE(i2c, max732x_id);
 116
 117 #ifdef CONFIG_OF
 118 static const struct of_device_id max732x_of_table[] = {
 119         { .compatible = "maxim,max7319" },
 120         { .compatible = "maxim,max7320" },
 121         { .compatible = "maxim,max7321" },
 122         { .compatible = "maxim,max7322" },
 123         { .compatible = "maxim,max7323" },
 124         { .compatible = "maxim,max7324" },
 125         { .compatible = "maxim,max7325" },
 126         { .compatible = "maxim,max7326" },
 127         { .compatible = "maxim,max7327" },
 128         { }
 129 };
 130 MODULE_DEVICE_TABLE(of, max732x_of_table);
 131 #endif
 132
 133 struct max732x_chip {
 134         struct gpio_chip gpio_chip;
 135
 136         struct i2c_client *client;      /* "main" client */
 137         struct i2c_client *client_dummy;
 138         struct i2c_client *client_group_a;
 139         struct i2c_client *client_group_b;
 140
 141         unsigned int    mask_group_a;
 142         unsigned int    dir_input;
 143         unsigned int    dir_output;
 144
 145         struct mutex    lock;
 146         uint8_t         reg_out[2];
 147
 148 #ifdef CONFIG_GPIO_MAX732X_IRQ
 149         struct mutex            irq_lock;
 150         uint8_t                 irq_mask;
 151         uint8_t                 irq_mask_cur;
 152         uint8_t                 irq_trig_raise;
 153         uint8_t                 irq_trig_fall;
 154         uint8_t                 irq_features;
 155 #endif
 156 };
 157
 158 static int max732x_writeb(struct max732x_chip *chip, int group_a, uint8_t val)
 159 {
 160         struct i2c_client *client;
 161         int ret;
 162
 163         client = group_a ? chip->client_group_a : chip->client_group_b;
 164         ret = i2c_smbus_write_byte(client, val);
 165         if (ret < 0) {
 166                 dev_err(&client->dev, "failed writing\n");
 167                 return ret;
 168         }
 169
 170         return 0;
 171 }
 172
 173 static int max732x_readb(struct max732x_chip *chip, int group_a, uint8_t *val)
 174 {
 175         struct i2c_client *client;
 176         int ret;
 177
 178         client = group_a ? chip->client_group_a : chip->client_group_b;
 179         ret = i2c_smbus_read_byte(client);
 180         if (ret < 0) {
 181                 dev_err(&client->dev, "failed reading\n");
 182                 return ret;
 183         }
 184
 185         *val = (uint8_t)ret;
 186         return 0;
 187 }
 188
 189 static inline int is_group_a(struct max732x_chip *chip, unsigned off)
 190 {
 191         return (1u << off) & chip->mask_group_a;
 192 }
 193
 194 static int max732x_gpio_get_value(struct gpio_chip *gc, unsigned off)
 195 {
 196         struct max732x_chip *chip = gpiochip_get_data(gc);
 197         uint8_t reg_val;
 198         int ret;
 199
 200         ret = max732x_readb(chip, is_group_a(chip, off), &reg_val);
 201         if (ret < 0)
 202                 return ret;
 203
 204         return !!(reg_val & (1u << (off & 0x7)));
 205 }
 206
 207 static void max732x_gpio_set_mask(struct gpio_chip *gc, unsigned off, int mask,
 208                                   int val)
 209 {
 210         struct max732x_chip *chip = gpiochip_get_data(gc);
 211         uint8_t reg_out;
 212         int ret;
 213
 214         mutex_lock(&chip->lock);
 215
 216         reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0];
 217         reg_out = (reg_out & ~mask) | (val & mask);
 218
 219         ret = max732x_writeb(chip, is_group_a(chip, off), reg_out);
 220         if (ret < 0)
 221                 goto out;
 222
 223         /* update the shadow register then */
 224         if (off > 7)
 225                 chip->reg_out[1] = reg_out;
 226         else
 227                 chip->reg_out[0] = reg_out;
 228 out:
 229         mutex_unlock(&chip->lock);
 230 }
 231
 232 static void max732x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
 233 {
 234         unsigned base = off & ~0x7;
 235         uint8_t mask = 1u << (off & 0x7);
 236
 237         max732x_gpio_set_mask(gc, base, mask, val << (off & 0x7));
 238 }
 239
 240 static void max732x_gpio_set_multiple(struct gpio_chip *gc,
 241                                       unsigned long *mask, unsigned long *bits)
 242 {
 243         unsigned mask_lo = mask[0] & 0xff;
 244         unsigned mask_hi = (mask[0] >> 8) & 0xff;
 245
 246         if (mask_lo)
 247                 max732x_gpio_set_mask(gc, 0, mask_lo, bits[0] & 0xff);
 248         if (mask_hi)
 249                 max732x_gpio_set_mask(gc, 8, mask_hi, (bits[0] >> 8) & 0xff);
 250 }
 251
 252 static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
 253 {
 254         struct max732x_chip *chip = gpiochip_get_data(gc);
 255         unsigned int mask = 1u << off;
 256
 257         if ((mask & chip->dir_input) == 0) {
 258                 dev_dbg(&chip->client->dev, "%s port %d is output only\n",
 259                         chip->client->name, off);
 260                 return -EACCES;
 261         }
 262
 263         /*
 264          * Open-drain pins must be set to high impedance (which is
 265          * equivalent to output-high) to be turned into an input.
 266          */
 267         if ((mask & chip->dir_output))
 268                 max732x_gpio_set_value(gc, off, 1);
 269
 270         return 0;
 271 }
 272
 273 static int max732x_gpio_direction_output(struct gpio_chip *gc,
 274                 unsigned off, int val)
 275 {
 276         struct max732x_chip *chip = gpiochip_get_data(gc);
 277         unsigned int mask = 1u << off;
 278
 279         if ((mask & chip->dir_output) == 0) {
 280                 dev_dbg(&chip->client->dev, "%s port %d is input only\n",
 281                         chip->client->name, off);
 282                 return -EACCES;
 283         }
 284
 285         max732x_gpio_set_value(gc, off, val);
 286         return 0;
 287 }
 288
 289 #ifdef CONFIG_GPIO_MAX732X_IRQ
 290 static int max732x_writew(struct max732x_chip *chip, uint16_t val)
 291 {
 292         int ret;
 293
 294         val = cpu_to_le16(val);
 295
 296         ret = i2c_master_send(chip->client_group_a, (char *)&val, 2);
 297         if (ret < 0) {
 298                 dev_err(&chip->client_group_a->dev, "failed writing\n");
 299                 return ret;
 300         }
 301
 302         return 0;
 303 }
 304
 305 static int max732x_readw(struct max732x_chip *chip, uint16_t *val)
 306 {
 307         int ret;
 308
 309         ret = i2c_master_recv(chip->client_group_a, (char *)val, 2);
 310         if (ret < 0) {
 311                 dev_err(&chip->client_group_a->dev, "failed reading\n");
 312                 return ret;
 313         }
 314
 315         *val = le16_to_cpu(*val);
 316         return 0;
 317 }
 318
 319 static void max732x_irq_update_mask(struct max732x_chip *chip)
 320 {
 321         uint16_t msg;
 322
 323         if (chip->irq_mask == chip->irq_mask_cur)
 324                 return;
 325
 326         chip->irq_mask = chip->irq_mask_cur;
 327
 328         if (chip->irq_features == INT_NO_MASK)
 329                 return;
 330
 331         mutex_lock(&chip->lock);
 332
 333         switch (chip->irq_features) {
 334         case INT_INDEP_MASK:
 335                 msg = (chip->irq_mask << 8) | chip->reg_out[0];
 336                 max732x_writew(chip, msg);
 337                 break;
 338
 339         case INT_MERGED_MASK:
 340                 msg = chip->irq_mask | chip->reg_out[0];
 341                 max732x_writeb(chip, 1, (uint8_t)msg);
 342                 break;
 343         }
 344
 345         mutex_unlock(&chip->lock);
 346 }
 347
 348 static void max732x_irq_mask(struct irq_data *d)
 349 {
 350         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 351         struct max732x_chip *chip = gpiochip_get_data(gc);
 352
 353         chip->irq_mask_cur &= ~(1 << d->hwirq);
 354 }
 355
 356 static void max732x_irq_unmask(struct irq_data *d)
 357 {
 358         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 359         struct max732x_chip *chip = gpiochip_get_data(gc);
 360
 361         chip->irq_mask_cur |= 1 << d->hwirq;
 362 }
 363
 364 static void max732x_irq_bus_lock(struct irq_data *d)
 365 {
 366         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 367         struct max732x_chip *chip = gpiochip_get_data(gc);
 368
 369         mutex_lock(&chip->irq_lock);
 370         chip->irq_mask_cur = chip->irq_mask;
 371 }
 372
 373 static void max732x_irq_bus_sync_unlock(struct irq_data *d)
 374 {
 375         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 376         struct max732x_chip *chip = gpiochip_get_data(gc);
 377         uint16_t new_irqs;
 378         uint16_t level;
 379
 380         max732x_irq_update_mask(chip);
 381
 382         new_irqs = chip->irq_trig_fall | chip->irq_trig_raise;
 383         while (new_irqs) {
 384                 level = __ffs(new_irqs);
 385                 max732x_gpio_direction_input(&chip->gpio_chip, level);
 386                 new_irqs &= ~(1 << level);
 387         }
 388
 389         mutex_unlock(&chip->irq_lock);
 390 }
 391
 392 static int max732x_irq_set_type(struct irq_data *d, unsigned int type)
 393 {
 394         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 395         struct max732x_chip *chip = gpiochip_get_data(gc);
 396         uint16_t off = d->hwirq;
 397         uint16_t mask = 1 << off;
 398
 399         if (!(mask & chip->dir_input)) {
 400                 dev_dbg(&chip->client->dev, "%s port %d is output only\n",
 401                         chip->client->name, off);
 402                 return -EACCES;
 403         }
 404
 405         if (!(type & IRQ_TYPE_EDGE_BOTH)) {
 406                 dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
 407                         d->irq, type);
 408                 return -EINVAL;
 409         }
 410
 411         if (type & IRQ_TYPE_EDGE_FALLING)
 412                 chip->irq_trig_fall |= mask;
 413         else
 414                 chip->irq_trig_fall &= ~mask;
 415
 416         if (type & IRQ_TYPE_EDGE_RISING)
 417                 chip->irq_trig_raise |= mask;
 418         else
 419                 chip->irq_trig_raise &= ~mask;
 420
 421         return 0;
 422 }
 423
 424 static int max732x_irq_set_wake(struct irq_data *data, unsigned int on)
 425 {
 426         struct max732x_chip *chip = irq_data_get_irq_chip_data(data);
 427
 428         irq_set_irq_wake(chip->client->irq, on);
 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         .irq_set_wake           = max732x_irq_set_wake,
 440 };
 441
 442 static uint8_t max732x_irq_pending(struct max732x_chip *chip)
 443 {
 444         uint8_t cur_stat;
 445         uint8_t old_stat;
 446         uint8_t trigger;
 447         uint8_t pending;
 448         uint16_t status;
 449         int ret;
 450
 451         ret = max732x_readw(chip, &status);
 452         if (ret)
 453                 return 0;
 454
 455         trigger = status >> 8;
 456         trigger &= chip->irq_mask;
 457
 458         if (!trigger)
 459                 return 0;
 460
 461         cur_stat = status & 0xFF;
 462         cur_stat &= chip->irq_mask;
 463
 464         old_stat = cur_stat ^ trigger;
 465
 466         pending = (old_stat & chip->irq_trig_fall) |
 467                   (cur_stat & chip->irq_trig_raise);
 468         pending &= trigger;
 469
 470         return pending;
 471 }
 472
 473 static irqreturn_t max732x_irq_handler(int irq, void *devid)
 474 {
 475         struct max732x_chip *chip = devid;
 476         uint8_t pending;
 477         uint8_t level;
 478
 479         pending = max732x_irq_pending(chip);
 480
 481         if (!pending)
 482                 return IRQ_HANDLED;
 483
 484         do {
 485                 level = __ffs(pending);
 486                 handle_nested_irq(irq_find_mapping(chip->gpio_chip.irq.domain,
 487                                                    level));
 488
 489                 pending &= ~(1 << level);
 490         } while (pending);
 491
 492         return IRQ_HANDLED;
 493 }
 494
 495 static int max732x_irq_setup(struct max732x_chip *chip,
 496                              const struct i2c_device_id *id)
 497 {
 498         struct i2c_client *client = chip->client;
 499         struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
 500         int has_irq = max732x_features[id->driver_data] >> 32;
 501         int irq_base = 0;
 502         int ret;
 503
 504         if (((pdata && pdata->irq_base) || client->irq)
 505                         && has_irq != INT_NONE) {
 506                 struct gpio_irq_chip *girq;
 507
 508                 if (pdata)
 509                         irq_base = pdata->irq_base;
 510                 chip->irq_features = has_irq;
 511                 mutex_init(&chip->irq_lock);
 512
 513                 ret = devm_request_threaded_irq(&client->dev, client->irq,
 514                                 NULL, max732x_irq_handler, IRQF_ONESHOT |
 515                                 IRQF_TRIGGER_FALLING | IRQF_SHARED,
 516                                 dev_name(&client->dev), chip);
 517                 if (ret) {
 518                         dev_err(&client->dev, "failed to request irq %d\n",
 519                                 client->irq);
 520                         return ret;
 521                 }
 522
 523                 girq = &chip->gpio_chip.irq;
 524                 girq->chip = &max732x_irq_chip;
 525                 /* This will let us handle the parent IRQ in the driver */
 526                 girq->parent_handler = NULL;
 527                 girq->num_parents = 0;
 528                 girq->parents = NULL;
 529                 girq->default_type = IRQ_TYPE_NONE;
 530                 girq->handler = handle_simple_irq;
 531                 girq->threaded = true;
 532                 girq->first = irq_base; /* FIXME: get rid of this */
 533         }
 534
 535         return 0;
 536 }
 537
 538 #else /* CONFIG_GPIO_MAX732X_IRQ */
 539 static int max732x_irq_setup(struct max732x_chip *chip,
 540                              const struct i2c_device_id *id)
 541 {
 542         struct i2c_client *client = chip->client;
 543         struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
 544         int has_irq = max732x_features[id->driver_data] >> 32;
 545
 546         if (((pdata && pdata->irq_base) || client->irq) && has_irq != INT_NONE)
 547                 dev_warn(&client->dev, "interrupt support not compiled in\n");
 548
 549         return 0;
 550 }
 551 #endif
 552
 553 static int max732x_setup_gpio(struct max732x_chip *chip,
 554                                         const struct i2c_device_id *id,
 555                                         unsigned gpio_start)
 556 {
 557         struct gpio_chip *gc = &chip->gpio_chip;
 558         uint32_t id_data = (uint32_t)max732x_features[id->driver_data];
 559         int i, port = 0;
 560
 561         for (i = 0; i < 16; i++, id_data >>= 2) {
 562                 unsigned int mask = 1 << port;
 563
 564                 switch (id_data & 0x3) {
 565                 case PORT_OUTPUT:
 566                         chip->dir_output |= mask;
 567                         break;
 568                 case PORT_INPUT:
 569                         chip->dir_input |= mask;
 570                         break;
 571                 case PORT_OPENDRAIN:
 572                         chip->dir_output |= mask;
 573                         chip->dir_input |= mask;
 574                         break;
 575                 default:
 576                         continue;
 577                 }
 578
 579                 if (i < 8)
 580                         chip->mask_group_a |= mask;
 581                 port++;
 582         }
 583
 584         if (chip->dir_input)
 585                 gc->direction_input = max732x_gpio_direction_input;
 586         if (chip->dir_output) {
 587                 gc->direction_output = max732x_gpio_direction_output;
 588                 gc->set = max732x_gpio_set_value;
 589                 gc->set_multiple = max732x_gpio_set_multiple;
 590         }
 591         gc->get = max732x_gpio_get_value;
 592         gc->can_sleep = true;
 593
 594         gc->base = gpio_start;
 595         gc->ngpio = port;
 596         gc->label = chip->client->name;
 597         gc->parent = &chip->client->dev;
 598         gc->owner = THIS_MODULE;
 599
 600         return port;
 601 }
 602
 603 static struct max732x_platform_data *of_gpio_max732x(struct device *dev)
 604 {
 605         struct max732x_platform_data *pdata;
 606
 607         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 608         if (!pdata)
 609                 return NULL;
 610
 611         pdata->gpio_base = -1;
 612
 613         return pdata;
 614 }
 615
 616 static int max732x_probe(struct i2c_client *client,
 617                                    const struct i2c_device_id *id)
 618 {
 619         struct max732x_platform_data *pdata;
 620         struct device_node *node;
 621         struct max732x_chip *chip;
 622         struct i2c_client *c;
 623         uint16_t addr_a, addr_b;
 624         int ret, nr_port;
 625
 626         pdata = dev_get_platdata(&client->dev);
 627         node = client->dev.of_node;
 628
 629         if (!pdata && node)
 630                 pdata = of_gpio_max732x(&client->dev);
 631
 632         if (!pdata) {
 633                 dev_dbg(&client->dev, "no platform data\n");
 634                 return -EINVAL;
 635         }
 636
 637         chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 638         if (chip == NULL)
 639                 return -ENOMEM;
 640         chip->client = client;
 641
 642         nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base);
 643         chip->gpio_chip.parent = &client->dev;
 644
 645         addr_a = (client->addr & 0x0f) | 0x60;
 646         addr_b = (client->addr & 0x0f) | 0x50;
 647
 648         switch (client->addr & 0x70) {
 649         case 0x60:
 650                 chip->client_group_a = client;
 651                 if (nr_port > 8) {
 652                         c = devm_i2c_new_dummy_device(&client->dev,
 653                                                       client->adapter, addr_b);
 654                         if (IS_ERR(c)) {
 655                                 dev_err(&client->dev,
 656                                         "Failed to allocate I2C device\n");
 657                                 return PTR_ERR(c);
 658                         }
 659                         chip->client_group_b = chip->client_dummy = c;
 660                 }
 661                 break;
 662         case 0x50:
 663                 chip->client_group_b = client;
 664                 if (nr_port > 8) {
 665                         c = devm_i2c_new_dummy_device(&client->dev,
 666                                                       client->adapter, addr_a);
 667                         if (IS_ERR(c)) {
 668                                 dev_err(&client->dev,
 669                                         "Failed to allocate I2C device\n");
 670                                 return PTR_ERR(c);
 671                         }
 672                         chip->client_group_a = chip->client_dummy = c;
 673                 }
 674                 break;
 675         default:
 676                 dev_err(&client->dev, "invalid I2C address specified %02x\n",
 677                                 client->addr);
 678                 return -EINVAL;
 679         }
 680
 681         if (nr_port > 8 && !chip->client_dummy) {
 682                 dev_err(&client->dev,
 683                         "Failed to allocate second group I2C device\n");
 684                 return -ENODEV;
 685         }
 686
 687         mutex_init(&chip->lock);
 688
 689         ret = max732x_readb(chip, is_group_a(chip, 0), &chip->reg_out[0]);
 690         if (ret)
 691                 return ret;
 692         if (nr_port > 8) {
 693                 ret = max732x_readb(chip, is_group_a(chip, 8), &chip->reg_out[1]);
 694                 if (ret)
 695                         return ret;
 696         }
 697
 698         ret = max732x_irq_setup(chip, id);
 699         if (ret)
 700                 return ret;
 701
 702         ret = devm_gpiochip_add_data(&client->dev, &chip->gpio_chip, chip);
 703         if (ret)
 704                 return ret;
 705
 706         if (pdata->setup) {
 707                 ret = pdata->setup(client, chip->gpio_chip.base,
 708                                 chip->gpio_chip.ngpio, pdata->context);
 709                 if (ret < 0)
 710                         dev_warn(&client->dev, "setup failed, %d\n", ret);
 711         }
 712
 713         i2c_set_clientdata(client, chip);
 714         return 0;
 715 }
 716
 717 static int max732x_remove(struct i2c_client *client)
 718 {
 719         struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
 720         struct max732x_chip *chip = i2c_get_clientdata(client);
 721
 722         if (pdata && pdata->teardown) {
 723                 int ret;
 724
 725                 ret = pdata->teardown(client, chip->gpio_chip.base,
 726                                 chip->gpio_chip.ngpio, pdata->context);
 727                 if (ret < 0) {
 728                         dev_err(&client->dev, "%s failed, %d\n",
 729                                         "teardown", ret);
 730                         return ret;
 731                 }
 732         }
 733
 734         return 0;
 735 }
 736
 737 static struct i2c_driver max732x_driver = {
 738         .driver = {
 739                 .name           = "max732x",
 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");