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 int max732x_writeb(struct max732x_chip *chip, int group_a, uint8_t val)
 162 {
 163         struct i2c_client *client;
 164         int ret;
 165
 166         client = group_a ? chip->client_group_a : chip->client_group_b;
 167         ret = i2c_smbus_write_byte(client, val);
 168         if (ret < 0) {
 169                 dev_err(&client->dev, "failed writing\n");
 170                 return ret;
 171         }
 172
 173         return 0;
 174 }
 175
 176 static int max732x_readb(struct max732x_chip *chip, int group_a, uint8_t *val)
 177 {
 178         struct i2c_client *client;
 179         int ret;
 180
 181         client = group_a ? chip->client_group_a : chip->client_group_b;
 182         ret = i2c_smbus_read_byte(client);
 183         if (ret < 0) {
 184                 dev_err(&client->dev, "failed reading\n");
 185                 return ret;
 186         }
 187
 188         *val = (uint8_t)ret;
 189         return 0;
 190 }
 191
 192 static inline int is_group_a(struct max732x_chip *chip, unsigned off)
 193 {
 194         return (1u << off) & chip->mask_group_a;
 195 }
 196
 197 static int max732x_gpio_get_value(struct gpio_chip *gc, unsigned off)
 198 {
 199         struct max732x_chip *chip = gpiochip_get_data(gc);
 200         uint8_t reg_val;
 201         int ret;
 202
 203         ret = max732x_readb(chip, is_group_a(chip, off), &reg_val);
 204         if (ret < 0)
 205                 return ret;
 206
 207         return !!(reg_val & (1u << (off & 0x7)));
 208 }
 209
 210 static void max732x_gpio_set_mask(struct gpio_chip *gc, unsigned off, int mask,
 211                                   int val)
 212 {
 213         struct max732x_chip *chip = gpiochip_get_data(gc);
 214         uint8_t reg_out;
 215         int ret;
 216
 217         mutex_lock(&chip->lock);
 218
 219         reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0];
 220         reg_out = (reg_out & ~mask) | (val & mask);
 221
 222         ret = max732x_writeb(chip, is_group_a(chip, off), reg_out);
 223         if (ret < 0)
 224                 goto out;
 225
 226         /* update the shadow register then */
 227         if (off > 7)
 228                 chip->reg_out[1] = reg_out;
 229         else
 230                 chip->reg_out[0] = reg_out;
 231 out:
 232         mutex_unlock(&chip->lock);
 233 }
 234
 235 static void max732x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
 236 {
 237         unsigned base = off & ~0x7;
 238         uint8_t mask = 1u << (off & 0x7);
 239
 240         max732x_gpio_set_mask(gc, base, mask, val << (off & 0x7));
 241 }
 242
 243 static void max732x_gpio_set_multiple(struct gpio_chip *gc,
 244                                       unsigned long *mask, unsigned long *bits)
 245 {
 246         unsigned mask_lo = mask[0] & 0xff;
 247         unsigned mask_hi = (mask[0] >> 8) & 0xff;
 248
 249         if (mask_lo)
 250                 max732x_gpio_set_mask(gc, 0, mask_lo, bits[0] & 0xff);
 251         if (mask_hi)
 252                 max732x_gpio_set_mask(gc, 8, mask_hi, (bits[0] >> 8) & 0xff);
 253 }
 254
 255 static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
 256 {
 257         struct max732x_chip *chip = gpiochip_get_data(gc);
 258         unsigned int mask = 1u << off;
 259
 260         if ((mask & chip->dir_input) == 0) {
 261                 dev_dbg(&chip->client->dev, "%s port %d is output only\n",
 262                         chip->client->name, off);
 263                 return -EACCES;
 264         }
 265
 266         /*
 267          * Open-drain pins must be set to high impedance (which is
 268          * equivalent to output-high) to be turned into an input.
 269          */
 270         if ((mask & chip->dir_output))
 271                 max732x_gpio_set_value(gc, off, 1);
 272
 273         return 0;
 274 }
 275
 276 static int max732x_gpio_direction_output(struct gpio_chip *gc,
 277                 unsigned off, int val)
 278 {
 279         struct max732x_chip *chip = gpiochip_get_data(gc);
 280         unsigned int mask = 1u << off;
 281
 282         if ((mask & chip->dir_output) == 0) {
 283                 dev_dbg(&chip->client->dev, "%s port %d is input only\n",
 284                         chip->client->name, off);
 285                 return -EACCES;
 286         }
 287
 288         max732x_gpio_set_value(gc, off, val);
 289         return 0;
 290 }
 291
 292 #ifdef CONFIG_GPIO_MAX732X_IRQ
 293 static int max732x_writew(struct max732x_chip *chip, uint16_t val)
 294 {
 295         int ret;
 296
 297         val = cpu_to_le16(val);
 298
 299         ret = i2c_master_send(chip->client_group_a, (char *)&val, 2);
 300         if (ret < 0) {
 301                 dev_err(&chip->client_group_a->dev, "failed writing\n");
 302                 return ret;
 303         }
 304
 305         return 0;
 306 }
 307
 308 static int max732x_readw(struct max732x_chip *chip, uint16_t *val)
 309 {
 310         int ret;
 311
 312         ret = i2c_master_recv(chip->client_group_a, (char *)val, 2);
 313         if (ret < 0) {
 314                 dev_err(&chip->client_group_a->dev, "failed reading\n");
 315                 return ret;
 316         }
 317
 318         *val = le16_to_cpu(*val);
 319         return 0;
 320 }
 321
 322 static void max732x_irq_update_mask(struct max732x_chip *chip)
 323 {
 324         uint16_t msg;
 325
 326         if (chip->irq_mask == chip->irq_mask_cur)
 327                 return;
 328
 329         chip->irq_mask = chip->irq_mask_cur;
 330
 331         if (chip->irq_features == INT_NO_MASK)
 332                 return;
 333
 334         mutex_lock(&chip->lock);
 335
 336         switch (chip->irq_features) {
 337         case INT_INDEP_MASK:
 338                 msg = (chip->irq_mask << 8) | chip->reg_out[0];
 339                 max732x_writew(chip, msg);
 340                 break;
 341
 342         case INT_MERGED_MASK:
 343                 msg = chip->irq_mask | chip->reg_out[0];
 344                 max732x_writeb(chip, 1, (uint8_t)msg);
 345                 break;
 346         }
 347
 348         mutex_unlock(&chip->lock);
 349 }
 350
 351 static void max732x_irq_mask(struct irq_data *d)
 352 {
 353         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 354         struct max732x_chip *chip = gpiochip_get_data(gc);
 355
 356         chip->irq_mask_cur &= ~(1 << d->hwirq);
 357 }
 358
 359 static void max732x_irq_unmask(struct irq_data *d)
 360 {
 361         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 362         struct max732x_chip *chip = gpiochip_get_data(gc);
 363
 364         chip->irq_mask_cur |= 1 << d->hwirq;
 365 }
 366
 367 static void max732x_irq_bus_lock(struct irq_data *d)
 368 {
 369         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 370         struct max732x_chip *chip = gpiochip_get_data(gc);
 371
 372         mutex_lock(&chip->irq_lock);
 373         chip->irq_mask_cur = chip->irq_mask;
 374 }
 375
 376 static void max732x_irq_bus_sync_unlock(struct irq_data *d)
 377 {
 378         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 379         struct max732x_chip *chip = gpiochip_get_data(gc);
 380         uint16_t new_irqs;
 381         uint16_t level;
 382
 383         max732x_irq_update_mask(chip);
 384
 385         new_irqs = chip->irq_trig_fall | chip->irq_trig_raise;
 386         while (new_irqs) {
 387                 level = __ffs(new_irqs);
 388                 max732x_gpio_direction_input(&chip->gpio_chip, level);
 389                 new_irqs &= ~(1 << level);
 390         }
 391
 392         mutex_unlock(&chip->irq_lock);
 393 }
 394
 395 static int max732x_irq_set_type(struct irq_data *d, unsigned int type)
 396 {
 397         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 398         struct max732x_chip *chip = gpiochip_get_data(gc);
 399         uint16_t off = d->hwirq;
 400         uint16_t mask = 1 << off;
 401
 402         if (!(mask & chip->dir_input)) {
 403                 dev_dbg(&chip->client->dev, "%s port %d is output only\n",
 404                         chip->client->name, off);
 405                 return -EACCES;
 406         }
 407
 408         if (!(type & IRQ_TYPE_EDGE_BOTH)) {
 409                 dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
 410                         d->irq, type);
 411                 return -EINVAL;
 412         }
 413
 414         if (type & IRQ_TYPE_EDGE_FALLING)
 415                 chip->irq_trig_fall |= mask;
 416         else
 417                 chip->irq_trig_fall &= ~mask;
 418
 419         if (type & IRQ_TYPE_EDGE_RISING)
 420                 chip->irq_trig_raise |= mask;
 421         else
 422                 chip->irq_trig_raise &= ~mask;
 423
 424         return 0;
 425 }
 426
 427 static int max732x_irq_set_wake(struct irq_data *data, unsigned int on)
 428 {
 429         struct max732x_chip *chip = irq_data_get_irq_chip_data(data);
 430
 431         irq_set_irq_wake(chip->client->irq, on);
 432         return 0;
 433 }
 434
 435 static struct irq_chip max732x_irq_chip = {
 436         .name                   = "max732x",
 437         .irq_mask               = max732x_irq_mask,
 438         .irq_unmask             = max732x_irq_unmask,
 439         .irq_bus_lock           = max732x_irq_bus_lock,
 440         .irq_bus_sync_unlock    = max732x_irq_bus_sync_unlock,
 441         .irq_set_type           = max732x_irq_set_type,
 442         .irq_set_wake           = max732x_irq_set_wake,
 443 };
 444
 445 static uint8_t max732x_irq_pending(struct max732x_chip *chip)
 446 {
 447         uint8_t cur_stat;
 448         uint8_t old_stat;
 449         uint8_t trigger;
 450         uint8_t pending;
 451         uint16_t status;
 452         int ret;
 453
 454         ret = max732x_readw(chip, &status);
 455         if (ret)
 456                 return 0;
 457
 458         trigger = status >> 8;
 459         trigger &= chip->irq_mask;
 460
 461         if (!trigger)
 462                 return 0;
 463
 464         cur_stat = status & 0xFF;
 465         cur_stat &= chip->irq_mask;
 466
 467         old_stat = cur_stat ^ trigger;
 468
 469         pending = (old_stat & chip->irq_trig_fall) |
 470                   (cur_stat & chip->irq_trig_raise);
 471         pending &= trigger;
 472
 473         return pending;
 474 }
 475
 476 static irqreturn_t max732x_irq_handler(int irq, void *devid)
 477 {
 478         struct max732x_chip *chip = devid;
 479         uint8_t pending;
 480         uint8_t level;
 481
 482         pending = max732x_irq_pending(chip);
 483
 484         if (!pending)
 485                 return IRQ_HANDLED;
 486
 487         do {
 488                 level = __ffs(pending);
 489                 handle_nested_irq(irq_find_mapping(chip->gpio_chip.irqdomain,
 490                                                    level));
 491
 492                 pending &= ~(1 << level);
 493         } while (pending);
 494
 495         return IRQ_HANDLED;
 496 }
 497
 498 static int max732x_irq_setup(struct max732x_chip *chip,
 499                              const struct i2c_device_id *id)
 500 {
 501         struct i2c_client *client = chip->client;
 502         struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
 503         int has_irq = max732x_features[id->driver_data] >> 32;
 504         int irq_base = 0;
 505         int ret;
 506
 507         if (((pdata && pdata->irq_base) || client->irq)
 508                         && has_irq != INT_NONE) {
 509                 if (pdata)
 510                         irq_base = pdata->irq_base;
 511                 chip->irq_features = has_irq;
 512                 mutex_init(&chip->irq_lock);
 513
 514                 ret = devm_request_threaded_irq(&client->dev, client->irq,
 515                                 NULL, max732x_irq_handler, IRQF_ONESHOT |
 516                                 IRQF_TRIGGER_FALLING | IRQF_SHARED,
 517                                 dev_name(&client->dev), chip);
 518                 if (ret) {
 519                         dev_err(&client->dev, "failed to request irq %d\n",
 520                                 client->irq);
 521                         return ret;
 522                 }
 523                 ret =  gpiochip_irqchip_add(&chip->gpio_chip,
 524                                             &max732x_irq_chip,
 525                                             irq_base,
 526                                             handle_simple_irq,
 527                                             IRQ_TYPE_NONE);
 528                 if (ret) {
 529                         dev_err(&client->dev,
 530                                 "could not connect irqchip to gpiochip\n");
 531                         return ret;
 532                 }
 533                 gpiochip_set_chained_irqchip(&chip->gpio_chip,
 534                                              &max732x_irq_chip,
 535                                              client->irq,
 536                                              NULL);
 537         }
 538
 539         return 0;
 540 }
 541
 542 #else /* CONFIG_GPIO_MAX732X_IRQ */
 543 static int max732x_irq_setup(struct max732x_chip *chip,
 544                              const struct i2c_device_id *id)
 545 {
 546         struct i2c_client *client = chip->client;
 547         struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
 548         int has_irq = max732x_features[id->driver_data] >> 32;
 549
 550         if (((pdata && pdata->irq_base) || client->irq) && has_irq != INT_NONE)
 551                 dev_warn(&client->dev, "interrupt support not compiled in\n");
 552
 553         return 0;
 554 }
 555 #endif
 556
 557 static int max732x_setup_gpio(struct max732x_chip *chip,
 558                                         const struct i2c_device_id *id,
 559                                         unsigned gpio_start)
 560 {
 561         struct gpio_chip *gc = &chip->gpio_chip;
 562         uint32_t id_data = (uint32_t)max732x_features[id->driver_data];
 563         int i, port = 0;
 564
 565         for (i = 0; i < 16; i++, id_data >>= 2) {
 566                 unsigned int mask = 1 << port;
 567
 568                 switch (id_data & 0x3) {
 569                 case PORT_OUTPUT:
 570                         chip->dir_output |= mask;
 571                         break;
 572                 case PORT_INPUT:
 573                         chip->dir_input |= mask;
 574                         break;
 575                 case PORT_OPENDRAIN:
 576                         chip->dir_output |= mask;
 577                         chip->dir_input |= mask;
 578                         break;
 579                 default:
 580                         continue;
 581                 }
 582
 583                 if (i < 8)
 584                         chip->mask_group_a |= mask;
 585                 port++;
 586         }
 587
 588         if (chip->dir_input)
 589                 gc->direction_input = max732x_gpio_direction_input;
 590         if (chip->dir_output) {
 591                 gc->direction_output = max732x_gpio_direction_output;
 592                 gc->set = max732x_gpio_set_value;
 593                 gc->set_multiple = max732x_gpio_set_multiple;
 594         }
 595         gc->get = max732x_gpio_get_value;
 596         gc->can_sleep = true;
 597
 598         gc->base = gpio_start;
 599         gc->ngpio = port;
 600         gc->label = chip->client->name;
 601         gc->parent = &chip->client->dev;
 602         gc->owner = THIS_MODULE;
 603
 604         return port;
 605 }
 606
 607 static struct max732x_platform_data *of_gpio_max732x(struct device *dev)
 608 {
 609         struct max732x_platform_data *pdata;
 610
 611         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 612         if (!pdata)
 613                 return NULL;
 614
 615         pdata->gpio_base = -1;
 616
 617         return pdata;
 618 }
 619
 620 static int max732x_probe(struct i2c_client *client,
 621                                    const struct i2c_device_id *id)
 622 {
 623         struct max732x_platform_data *pdata;
 624         struct device_node *node;
 625         struct max732x_chip *chip;
 626         struct i2c_client *c;
 627         uint16_t addr_a, addr_b;
 628         int ret, nr_port;
 629
 630         pdata = dev_get_platdata(&client->dev);
 631         node = client->dev.of_node;
 632
 633         if (!pdata && node)
 634                 pdata = of_gpio_max732x(&client->dev);
 635
 636         if (!pdata) {
 637                 dev_dbg(&client->dev, "no platform data\n");
 638                 return -EINVAL;
 639         }
 640
 641         chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 642         if (chip == NULL)
 643                 return -ENOMEM;
 644         chip->client = client;
 645
 646         nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base);
 647         chip->gpio_chip.parent = &client->dev;
 648
 649         addr_a = (client->addr & 0x0f) | 0x60;
 650         addr_b = (client->addr & 0x0f) | 0x50;
 651
 652         switch (client->addr & 0x70) {
 653         case 0x60:
 654                 chip->client_group_a = client;
 655                 if (nr_port > 8) {
 656                         c = i2c_new_dummy(client->adapter, addr_b);
 657                         chip->client_group_b = chip->client_dummy = c;
 658                 }
 659                 break;
 660         case 0x50:
 661                 chip->client_group_b = client;
 662                 if (nr_port > 8) {
 663                         c = i2c_new_dummy(client->adapter, addr_a);
 664                         chip->client_group_a = chip->client_dummy = c;
 665                 }
 666                 break;
 667         default:
 668                 dev_err(&client->dev, "invalid I2C address specified %02x\n",
 669                                 client->addr);
 670                 ret = -EINVAL;
 671                 goto out_failed;
 672         }
 673
 674         if (nr_port > 8 && !chip->client_dummy) {
 675                 dev_err(&client->dev,
 676                         "Failed to allocate second group I2C device\n");
 677                 ret = -ENODEV;
 678                 goto out_failed;
 679         }
 680
 681         mutex_init(&chip->lock);
 682
 683         ret = max732x_readb(chip, is_group_a(chip, 0), &chip->reg_out[0]);
 684         if (ret)
 685                 goto out_failed;
 686         if (nr_port > 8) {
 687                 ret = max732x_readb(chip, is_group_a(chip, 8), &chip->reg_out[1]);
 688                 if (ret)
 689                         goto out_failed;
 690         }
 691
 692         ret = gpiochip_add_data(&chip->gpio_chip, chip);
 693         if (ret)
 694                 goto out_failed;
 695
 696         ret = max732x_irq_setup(chip, id);
 697         if (ret) {
 698                 gpiochip_remove(&chip->gpio_chip);
 699                 goto out_failed;
 700         }
 701
 702         if (pdata && pdata->setup) {
 703                 ret = pdata->setup(client, chip->gpio_chip.base,
 704                                 chip->gpio_chip.ngpio, pdata->context);
 705                 if (ret < 0)
 706                         dev_warn(&client->dev, "setup failed, %d\n", ret);
 707         }
 708
 709         i2c_set_clientdata(client, chip);
 710         return 0;
 711
 712 out_failed:
 713         if (chip->client_dummy)
 714                 i2c_unregister_device(chip->client_dummy);
 715         return ret;
 716 }
 717
 718 static int max732x_remove(struct i2c_client *client)
 719 {
 720         struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
 721         struct max732x_chip *chip = i2c_get_clientdata(client);
 722
 723         if (pdata && pdata->teardown) {
 724                 int ret;
 725
 726                 ret = pdata->teardown(client, chip->gpio_chip.base,
 727                                 chip->gpio_chip.ngpio, pdata->context);
 728                 if (ret < 0) {
 729                         dev_err(&client->dev, "%s failed, %d\n",
 730                                         "teardown", ret);
 731                         return ret;
 732                 }
 733         }
 734
 735         gpiochip_remove(&chip->gpio_chip);
 736
 737         /* unregister any dummy i2c_client */
 738         if (chip->client_dummy)
 739                 i2c_unregister_device(chip->client_dummy);
 740
 741         return 0;
 742 }
 743
 744 static struct i2c_driver max732x_driver = {
 745         .driver = {
 746                 .name           = "max732x",
 747                 .of_match_table = of_match_ptr(max732x_of_table),
 748         },
 749         .probe          = max732x_probe,
 750         .remove         = max732x_remove,
 751         .id_table       = max732x_id,
 752 };
 753
 754 static int __init max732x_init(void)
 755 {
 756         return i2c_add_driver(&max732x_driver);
 757 }
 758 /* register after i2c postcore initcall and before
 759  * subsys initcalls that may rely on these GPIOs
 760  */
 761 subsys_initcall(max732x_init);
 762
 763 static void __exit max732x_exit(void)
 764 {
 765         i2c_del_driver(&max732x_driver);
 766 }
 767 module_exit(max732x_exit);
 768
 769 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
 770 MODULE_DESCRIPTION("GPIO expander driver for MAX732X");
 771 MODULE_LICENSE("GPL");