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  *
   8  *  Derived from drivers/gpio/pca953x.c
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; version 2 of the License.
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/slab.h>
  18 #include <linux/string.h>
  19 #include <linux/gpio.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/irq.h>
  22 #include <linux/irqdomain.h>
  23 #include <linux/i2c.h>
  24 #include <linux/i2c/max732x.h>
  25 #include <linux/of.h>
  26
  27
  28 /*
  29  * Each port of MAX732x (including MAX7319) falls into one of the
  30  * following three types:
  31  *
  32  *   - Push Pull Output
  33  *   - Input
  34  *   - Open Drain I/O
  35  *
  36  * designated by 'O', 'I' and 'P' individually according to MAXIM's
  37  * datasheets. 'I' and 'P' ports are interrupt capables, some with
  38  * a dedicated interrupt mask.
  39  *
  40  * There are two groups of I/O ports, each group usually includes
  41  * up to 8 I/O ports, and is accessed by a specific I2C address:
  42  *
  43  *   - Group A : by I2C address 0b'110xxxx
  44  *   - Group B : by I2C address 0b'101xxxx
  45  *
  46  * where 'xxxx' is decided by the connections of pin AD2/AD0.  The
  47  * address used also affects the initial state of output signals.
  48  *
  49  * Within each group of ports, there are five known combinations of
  50  * I/O ports: 4I4O, 4P4O, 8I, 8P, 8O, see the definitions below for
  51  * the detailed organization of these ports. Only Goup A is interrupt
  52  * capable.
  53  *
  54  * GPIO numbers start from 'gpio_base + 0' to 'gpio_base + 8/16',
  55  * and GPIOs from GROUP_A are numbered before those from GROUP_B
  56  * (if there are two groups).
  57  *
  58  * NOTE: MAX7328/MAX7329 are drop-in replacements for PCF8574/a, so
  59  * they are not supported by this driver.
  60  */
  61
  62 #define PORT_NONE       0x0     /* '/' No Port */
  63 #define PORT_OUTPUT     0x1     /* 'O' Push-Pull, Output Only */
  64 #define PORT_INPUT      0x2     /* 'I' Input Only */
  65 #define PORT_OPENDRAIN  0x3     /* 'P' Open-Drain, I/O */
  66
  67 #define IO_4I4O         0x5AA5  /* O7 O6 I5 I4 I3 I2 O1 O0 */
  68 #define IO_4P4O         0x5FF5  /* O7 O6 P5 P4 P3 P2 O1 O0 */
  69 #define IO_8I           0xAAAA  /* I7 I6 I5 I4 I3 I2 I1 I0 */
  70 #define IO_8P           0xFFFF  /* P7 P6 P5 P4 P3 P2 P1 P0 */
  71 #define IO_8O           0x5555  /* O7 O6 O5 O4 O3 O2 O1 O0 */
  72
  73 #define GROUP_A(x)      ((x) & 0xffff)  /* I2C Addr: 0b'110xxxx */
  74 #define GROUP_B(x)      ((x) << 16)     /* I2C Addr: 0b'101xxxx */
  75
  76 #define INT_NONE        0x0     /* No interrupt capability */
  77 #define INT_NO_MASK     0x1     /* Has interrupts, no mask */
  78 #define INT_INDEP_MASK  0x2     /* Has interrupts, independent mask */
  79 #define INT_MERGED_MASK 0x3     /* Has interrupts, merged mask */
  80
  81 #define INT_CAPS(x)     (((uint64_t)(x)) << 32)
  82
  83 enum {
  84         MAX7319,
  85         MAX7320,
  86         MAX7321,
  87         MAX7322,
  88         MAX7323,
  89         MAX7324,
  90         MAX7325,
  91         MAX7326,
  92         MAX7327,
  93 };
  94
  95 static uint64_t max732x_features[] = {
  96         [MAX7319] = GROUP_A(IO_8I) | INT_CAPS(INT_MERGED_MASK),
  97         [MAX7320] = GROUP_B(IO_8O),
  98         [MAX7321] = GROUP_A(IO_8P) | INT_CAPS(INT_NO_MASK),
  99         [MAX7322] = GROUP_A(IO_4I4O) | INT_CAPS(INT_MERGED_MASK),
 100         [MAX7323] = GROUP_A(IO_4P4O) | INT_CAPS(INT_INDEP_MASK),
 101         [MAX7324] = GROUP_A(IO_8I) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK),
 102         [MAX7325] = GROUP_A(IO_8P) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK),
 103         [MAX7326] = GROUP_A(IO_4I4O) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK),
 104         [MAX7327] = GROUP_A(IO_4P4O) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK),
 105 };
 106
 107 static const struct i2c_device_id max732x_id[] = {
 108         { "max7319", MAX7319 },
 109         { "max7320", MAX7320 },
 110         { "max7321", MAX7321 },
 111         { "max7322", MAX7322 },
 112         { "max7323", MAX7323 },
 113         { "max7324", MAX7324 },
 114         { "max7325", MAX7325 },
 115         { "max7326", MAX7326 },
 116         { "max7327", MAX7327 },
 117         { },
 118 };
 119 MODULE_DEVICE_TABLE(i2c, max732x_id);
 120
 121 #ifdef CONFIG_OF
 122 static const struct of_device_id max732x_of_table[] = {
 123         { .compatible = "maxim,max7319" },
 124         { .compatible = "maxim,max7320" },
 125         { .compatible = "maxim,max7321" },
 126         { .compatible = "maxim,max7322" },
 127         { .compatible = "maxim,max7323" },
 128         { .compatible = "maxim,max7324" },
 129         { .compatible = "maxim,max7325" },
 130         { .compatible = "maxim,max7326" },
 131         { .compatible = "maxim,max7327" },
 132         { }
 133 };
 134 MODULE_DEVICE_TABLE(of, max732x_of_table);
 135 #endif
 136
 137 struct max732x_chip {
 138         struct gpio_chip gpio_chip;
 139
 140         struct i2c_client *client;      /* "main" client */
 141         struct i2c_client *client_dummy;
 142         struct i2c_client *client_group_a;
 143         struct i2c_client *client_group_b;
 144
 145         unsigned int    mask_group_a;
 146         unsigned int    dir_input;
 147         unsigned int    dir_output;
 148
 149         struct mutex    lock;
 150         uint8_t         reg_out[2];
 151
 152 #ifdef CONFIG_GPIO_MAX732X_IRQ
 153         struct irq_domain       *irq_domain;
 154         struct mutex            irq_lock;
 155         int                     irq_base;
 156         uint8_t                 irq_mask;
 157         uint8_t                 irq_mask_cur;
 158         uint8_t                 irq_trig_raise;
 159         uint8_t                 irq_trig_fall;
 160         uint8_t                 irq_features;
 161 #endif
 162 };
 163
 164 static inline struct max732x_chip *to_max732x(struct gpio_chip *gc)
 165 {
 166         return container_of(gc, struct max732x_chip, gpio_chip);
 167 }
 168
 169 static int max732x_writeb(struct max732x_chip *chip, int group_a, uint8_t val)
 170 {
 171         struct i2c_client *client;
 172         int ret;
 173
 174         client = group_a ? chip->client_group_a : chip->client_group_b;
 175         ret = i2c_smbus_write_byte(client, val);
 176         if (ret < 0) {
 177                 dev_err(&client->dev, "failed writing\n");
 178                 return ret;
 179         }
 180
 181         return 0;
 182 }
 183
 184 static int max732x_readb(struct max732x_chip *chip, int group_a, uint8_t *val)
 185 {
 186         struct i2c_client *client;
 187         int ret;
 188
 189         client = group_a ? chip->client_group_a : chip->client_group_b;
 190         ret = i2c_smbus_read_byte(client);
 191         if (ret < 0) {
 192                 dev_err(&client->dev, "failed reading\n");
 193                 return ret;
 194         }
 195
 196         *val = (uint8_t)ret;
 197         return 0;
 198 }
 199
 200 static inline int is_group_a(struct max732x_chip *chip, unsigned off)
 201 {
 202         return (1u << off) & chip->mask_group_a;
 203 }
 204
 205 static int max732x_gpio_get_value(struct gpio_chip *gc, unsigned off)
 206 {
 207         struct max732x_chip *chip = to_max732x(gc);
 208         uint8_t reg_val;
 209         int ret;
 210
 211         ret = max732x_readb(chip, is_group_a(chip, off), &reg_val);
 212         if (ret < 0)
 213                 return 0;
 214
 215         return reg_val & (1u << (off & 0x7));
 216 }
 217
 218 static void max732x_gpio_set_mask(struct gpio_chip *gc, unsigned off, int mask,
 219                                   int val)
 220 {
 221         struct max732x_chip *chip = to_max732x(gc);
 222         uint8_t reg_out;
 223         int ret;
 224
 225         mutex_lock(&chip->lock);
 226
 227         reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0];
 228         reg_out = (reg_out & ~mask) | (val & mask);
 229
 230         ret = max732x_writeb(chip, is_group_a(chip, off), reg_out);
 231         if (ret < 0)
 232                 goto out;
 233
 234         /* update the shadow register then */
 235         if (off > 7)
 236                 chip->reg_out[1] = reg_out;
 237         else
 238                 chip->reg_out[0] = reg_out;
 239 out:
 240         mutex_unlock(&chip->lock);
 241 }
 242
 243 static void max732x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
 244 {
 245         unsigned base = off & ~0x7;
 246         uint8_t mask = 1u << (off & 0x7);
 247
 248         max732x_gpio_set_mask(gc, base, mask, val << (off & 0x7));
 249 }
 250
 251 static void max732x_gpio_set_multiple(struct gpio_chip *gc,
 252                                       unsigned long *mask, unsigned long *bits)
 253 {
 254         unsigned mask_lo = mask[0] & 0xff;
 255         unsigned mask_hi = (mask[0] >> 8) & 0xff;
 256
 257         if (mask_lo)
 258                 max732x_gpio_set_mask(gc, 0, mask_lo, bits[0] & 0xff);
 259         if (mask_hi)
 260                 max732x_gpio_set_mask(gc, 8, mask_hi, (bits[0] >> 8) & 0xff);
 261 }
 262
 263 static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
 264 {
 265         struct max732x_chip *chip = to_max732x(gc);
 266         unsigned int mask = 1u << off;
 267
 268         if ((mask & chip->dir_input) == 0) {
 269                 dev_dbg(&chip->client->dev, "%s port %d is output only\n",
 270                         chip->client->name, off);
 271                 return -EACCES;
 272         }
 273
 274         /*
 275          * Open-drain pins must be set to high impedance (which is
 276          * equivalent to output-high) to be turned into an input.
 277          */
 278         if ((mask & chip->dir_output))
 279                 max732x_gpio_set_value(gc, off, 1);
 280
 281         return 0;
 282 }
 283
 284 static int max732x_gpio_direction_output(struct gpio_chip *gc,
 285                 unsigned off, int val)
 286 {
 287         struct max732x_chip *chip = to_max732x(gc);
 288         unsigned int mask = 1u << off;
 289
 290         if ((mask & chip->dir_output) == 0) {
 291                 dev_dbg(&chip->client->dev, "%s port %d is input only\n",
 292                         chip->client->name, off);
 293                 return -EACCES;
 294         }
 295
 296         max732x_gpio_set_value(gc, off, val);
 297         return 0;
 298 }
 299
 300 #ifdef CONFIG_GPIO_MAX732X_IRQ
 301 static int max732x_writew(struct max732x_chip *chip, uint16_t val)
 302 {
 303         int ret;
 304
 305         val = cpu_to_le16(val);
 306
 307         ret = i2c_master_send(chip->client_group_a, (char *)&val, 2);
 308         if (ret < 0) {
 309                 dev_err(&chip->client_group_a->dev, "failed writing\n");
 310                 return ret;
 311         }
 312
 313         return 0;
 314 }
 315
 316 static int max732x_readw(struct max732x_chip *chip, uint16_t *val)
 317 {
 318         int ret;
 319
 320         ret = i2c_master_recv(chip->client_group_a, (char *)val, 2);
 321         if (ret < 0) {
 322                 dev_err(&chip->client_group_a->dev, "failed reading\n");
 323                 return ret;
 324         }
 325
 326         *val = le16_to_cpu(*val);
 327         return 0;
 328 }
 329
 330 static void max732x_irq_update_mask(struct max732x_chip *chip)
 331 {
 332         uint16_t msg;
 333
 334         if (chip->irq_mask == chip->irq_mask_cur)
 335                 return;
 336
 337         chip->irq_mask = chip->irq_mask_cur;
 338
 339         if (chip->irq_features == INT_NO_MASK)
 340                 return;
 341
 342         mutex_lock(&chip->lock);
 343
 344         switch (chip->irq_features) {
 345         case INT_INDEP_MASK:
 346                 msg = (chip->irq_mask << 8) | chip->reg_out[0];
 347                 max732x_writew(chip, msg);
 348                 break;
 349
 350         case INT_MERGED_MASK:
 351                 msg = chip->irq_mask | chip->reg_out[0];
 352                 max732x_writeb(chip, 1, (uint8_t)msg);
 353                 break;
 354         }
 355
 356         mutex_unlock(&chip->lock);
 357 }
 358
 359 static int max732x_gpio_to_irq(struct gpio_chip *gc, unsigned off)
 360 {
 361         struct max732x_chip *chip = to_max732x(gc);
 362
 363         if (chip->irq_domain) {
 364                 return irq_create_mapping(chip->irq_domain,
 365                                 chip->irq_base + off);
 366         } else {
 367                 return -ENXIO;
 368         }
 369 }
 370
 371 static void max732x_irq_mask(struct irq_data *d)
 372 {
 373         struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
 374
 375         chip->irq_mask_cur &= ~(1 << d->hwirq);
 376 }
 377
 378 static void max732x_irq_unmask(struct irq_data *d)
 379 {
 380         struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
 381
 382         chip->irq_mask_cur |= 1 << d->hwirq;
 383 }
 384
 385 static void max732x_irq_bus_lock(struct irq_data *d)
 386 {
 387         struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
 388
 389         mutex_lock(&chip->irq_lock);
 390         chip->irq_mask_cur = chip->irq_mask;
 391 }
 392
 393 static void max732x_irq_bus_sync_unlock(struct irq_data *d)
 394 {
 395         struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
 396         uint16_t new_irqs;
 397         uint16_t level;
 398
 399         max732x_irq_update_mask(chip);
 400
 401         new_irqs = chip->irq_trig_fall | chip->irq_trig_raise;
 402         while (new_irqs) {
 403                 level = __ffs(new_irqs);
 404                 max732x_gpio_direction_input(&chip->gpio_chip, level);
 405                 new_irqs &= ~(1 << level);
 406         }
 407
 408         mutex_unlock(&chip->irq_lock);
 409 }
 410
 411 static int max732x_irq_set_type(struct irq_data *d, unsigned int type)
 412 {
 413         struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
 414         uint16_t off = d->hwirq;
 415         uint16_t mask = 1 << off;
 416
 417         if (!(mask & chip->dir_input)) {
 418                 dev_dbg(&chip->client->dev, "%s port %d is output only\n",
 419                         chip->client->name, off);
 420                 return -EACCES;
 421         }
 422
 423         if (!(type & IRQ_TYPE_EDGE_BOTH)) {
 424                 dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
 425                         d->irq, type);
 426                 return -EINVAL;
 427         }
 428
 429         if (type & IRQ_TYPE_EDGE_FALLING)
 430                 chip->irq_trig_fall |= mask;
 431         else
 432                 chip->irq_trig_fall &= ~mask;
 433
 434         if (type & IRQ_TYPE_EDGE_RISING)
 435                 chip->irq_trig_raise |= mask;
 436         else
 437                 chip->irq_trig_raise &= ~mask;
 438
 439         return 0;
 440 }
 441
 442 static struct irq_chip max732x_irq_chip = {
 443         .name                   = "max732x",
 444         .irq_mask               = max732x_irq_mask,
 445         .irq_unmask             = max732x_irq_unmask,
 446         .irq_bus_lock           = max732x_irq_bus_lock,
 447         .irq_bus_sync_unlock    = max732x_irq_bus_sync_unlock,
 448         .irq_set_type           = max732x_irq_set_type,
 449 };
 450
 451 static uint8_t max732x_irq_pending(struct max732x_chip *chip)
 452 {
 453         uint8_t cur_stat;
 454         uint8_t old_stat;
 455         uint8_t trigger;
 456         uint8_t pending;
 457         uint16_t status;
 458         int ret;
 459
 460         ret = max732x_readw(chip, &status);
 461         if (ret)
 462                 return 0;
 463
 464         trigger = status >> 8;
 465         trigger &= chip->irq_mask;
 466
 467         if (!trigger)
 468                 return 0;
 469
 470         cur_stat = status & 0xFF;
 471         cur_stat &= chip->irq_mask;
 472
 473         old_stat = cur_stat ^ trigger;
 474
 475         pending = (old_stat & chip->irq_trig_fall) |
 476                   (cur_stat & chip->irq_trig_raise);
 477         pending &= trigger;
 478
 479         return pending;
 480 }
 481
 482 static irqreturn_t max732x_irq_handler(int irq, void *devid)
 483 {
 484         struct max732x_chip *chip = devid;
 485         uint8_t pending;
 486         uint8_t level;
 487
 488         pending = max732x_irq_pending(chip);
 489
 490         if (!pending)
 491                 return IRQ_HANDLED;
 492
 493         do {
 494                 level = __ffs(pending);
 495                 handle_nested_irq(irq_find_mapping(chip->irq_domain, level));
 496
 497                 pending &= ~(1 << level);
 498         } while (pending);
 499
 500         return IRQ_HANDLED;
 501 }
 502
 503 static int max732x_irq_map(struct irq_domain *h, unsigned int virq,
 504                 irq_hw_number_t hw)
 505 {
 506         struct max732x_chip *chip = h->host_data;
 507
 508         if (!(chip->dir_input & (1 << hw))) {
 509                 dev_err(&chip->client->dev,
 510                                 "Attempt to map output line as IRQ line: %lu\n",
 511                                 hw);
 512                 return -EPERM;
 513         }
 514
 515         irq_set_chip_data(virq, chip);
 516         irq_set_chip_and_handler(virq, &max732x_irq_chip,
 517                         handle_edge_irq);
 518         irq_set_nested_thread(virq, 1);
 519 #ifdef CONFIG_ARM
 520         /* ARM needs us to explicitly flag the IRQ as valid
 521          * and will set them noprobe when we do so. */
 522         set_irq_flags(virq, IRQF_VALID);
 523 #else
 524         irq_set_noprobe(virq);
 525 #endif
 526
 527         return 0;
 528 }
 529
 530 static struct irq_domain_ops max732x_irq_domain_ops = {
 531         .map    = max732x_irq_map,
 532         .xlate  = irq_domain_xlate_twocell,
 533 };
 534
 535 static void max732x_irq_teardown(struct max732x_chip *chip)
 536 {
 537         if (chip->client->irq && chip->irq_domain)
 538                 irq_domain_remove(chip->irq_domain);
 539 }
 540
 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         int ret;
 548
 549         if (((pdata && pdata->irq_base) || client->irq)
 550                         && has_irq != INT_NONE) {
 551                 if (pdata)
 552                         chip->irq_base = pdata->irq_base;
 553                 chip->irq_features = has_irq;
 554                 mutex_init(&chip->irq_lock);
 555
 556                 chip->irq_domain = irq_domain_add_simple(client->dev.of_node,
 557                                 chip->gpio_chip.ngpio, chip->irq_base,
 558                                 &max732x_irq_domain_ops, chip);
 559                 if (!chip->irq_domain) {
 560                         dev_err(&client->dev, "Failed to create IRQ domain\n");
 561                         return -ENOMEM;
 562                 }
 563
 564                 ret = request_threaded_irq(client->irq,
 565                                            NULL,
 566                                            max732x_irq_handler,
 567                                            IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 568                                            dev_name(&client->dev), chip);
 569                 if (ret) {
 570                         dev_err(&client->dev, "failed to request irq %d\n",
 571                                 client->irq);
 572                         goto out_failed;
 573                 }
 574
 575                 chip->gpio_chip.to_irq = max732x_gpio_to_irq;
 576         }
 577
 578         return 0;
 579
 580 out_failed:
 581         max732x_irq_teardown(chip);
 582         return ret;
 583 }
 584
 585 #else /* CONFIG_GPIO_MAX732X_IRQ */
 586 static int max732x_irq_setup(struct max732x_chip *chip,
 587                              const struct i2c_device_id *id)
 588 {
 589         struct i2c_client *client = chip->client;
 590         struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
 591         int has_irq = max732x_features[id->driver_data] >> 32;
 592
 593         if (((pdata && pdata->irq_base) || client->irq) && has_irq != INT_NONE)
 594                 dev_warn(&client->dev, "interrupt support not compiled in\n");
 595
 596         return 0;
 597 }
 598
 599 static void max732x_irq_teardown(struct max732x_chip *chip)
 600 {
 601 }
 602 #endif
 603
 604 static int max732x_setup_gpio(struct max732x_chip *chip,
 605                                         const struct i2c_device_id *id,
 606                                         unsigned gpio_start)
 607 {
 608         struct gpio_chip *gc = &chip->gpio_chip;
 609         uint32_t id_data = (uint32_t)max732x_features[id->driver_data];
 610         int i, port = 0;
 611
 612         for (i = 0; i < 16; i++, id_data >>= 2) {
 613                 unsigned int mask = 1 << port;
 614
 615                 switch (id_data & 0x3) {
 616                 case PORT_OUTPUT:
 617                         chip->dir_output |= mask;
 618                         break;
 619                 case PORT_INPUT:
 620                         chip->dir_input |= mask;
 621                         break;
 622                 case PORT_OPENDRAIN:
 623                         chip->dir_output |= mask;
 624                         chip->dir_input |= mask;
 625                         break;
 626                 default:
 627                         continue;
 628                 }
 629
 630                 if (i < 8)
 631                         chip->mask_group_a |= mask;
 632                 port++;
 633         }
 634
 635         if (chip->dir_input)
 636                 gc->direction_input = max732x_gpio_direction_input;
 637         if (chip->dir_output) {
 638                 gc->direction_output = max732x_gpio_direction_output;
 639                 gc->set = max732x_gpio_set_value;
 640                 gc->set_multiple = max732x_gpio_set_multiple;
 641         }
 642         gc->get = max732x_gpio_get_value;
 643         gc->can_sleep = true;
 644
 645         gc->base = gpio_start;
 646         gc->ngpio = port;
 647         gc->label = chip->client->name;
 648         gc->owner = THIS_MODULE;
 649
 650         return port;
 651 }
 652
 653 static struct max732x_platform_data *of_gpio_max732x(struct device *dev)
 654 {
 655         struct max732x_platform_data *pdata;
 656
 657         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 658         if (!pdata)
 659                 return NULL;
 660
 661         pdata->gpio_base = -1;
 662
 663         return pdata;
 664 }
 665
 666 static int max732x_probe(struct i2c_client *client,
 667                                    const struct i2c_device_id *id)
 668 {
 669         struct max732x_platform_data *pdata;
 670         struct device_node *node;
 671         struct max732x_chip *chip;
 672         struct i2c_client *c;
 673         uint16_t addr_a, addr_b;
 674         int ret, nr_port;
 675
 676         pdata = dev_get_platdata(&client->dev);
 677         node = client->dev.of_node;
 678
 679         if (!pdata && node)
 680                 pdata = of_gpio_max732x(&client->dev);
 681
 682         if (!pdata) {
 683                 dev_dbg(&client->dev, "no platform data\n");
 684                 return -EINVAL;
 685         }
 686
 687         chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 688         if (chip == NULL)
 689                 return -ENOMEM;
 690         chip->client = client;
 691
 692         nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base);
 693         chip->gpio_chip.dev = &client->dev;
 694
 695         addr_a = (client->addr & 0x0f) | 0x60;
 696         addr_b = (client->addr & 0x0f) | 0x50;
 697
 698         switch (client->addr & 0x70) {
 699         case 0x60:
 700                 chip->client_group_a = client;
 701                 if (nr_port > 8) {
 702                         c = i2c_new_dummy(client->adapter, addr_b);
 703                         chip->client_group_b = chip->client_dummy = c;
 704                 }
 705                 break;
 706         case 0x50:
 707                 chip->client_group_b = client;
 708                 if (nr_port > 8) {
 709                         c = i2c_new_dummy(client->adapter, addr_a);
 710                         chip->client_group_a = chip->client_dummy = c;
 711                 }
 712                 break;
 713         default:
 714                 dev_err(&client->dev, "invalid I2C address specified %02x\n",
 715                                 client->addr);
 716                 ret = -EINVAL;
 717                 goto out_failed;
 718         }
 719
 720         if (nr_port > 8 && !chip->client_dummy) {
 721                 dev_err(&client->dev,
 722                         "Failed to allocate second group I2C device\n");
 723                 ret = -ENODEV;
 724                 goto out_failed;
 725         }
 726
 727         mutex_init(&chip->lock);
 728
 729         max732x_readb(chip, is_group_a(chip, 0), &chip->reg_out[0]);
 730         if (nr_port > 8)
 731                 max732x_readb(chip, is_group_a(chip, 8), &chip->reg_out[1]);
 732
 733         ret = max732x_irq_setup(chip, id);
 734         if (ret)
 735                 goto out_failed;
 736
 737         ret = gpiochip_add(&chip->gpio_chip);
 738         if (ret)
 739                 goto out_failed;
 740
 741         if (pdata && pdata->setup) {
 742                 ret = pdata->setup(client, chip->gpio_chip.base,
 743                                 chip->gpio_chip.ngpio, pdata->context);
 744                 if (ret < 0)
 745                         dev_warn(&client->dev, "setup failed, %d\n", ret);
 746         }
 747
 748         i2c_set_clientdata(client, chip);
 749         return 0;
 750
 751 out_failed:
 752         if (chip->client_dummy)
 753                 i2c_unregister_device(chip->client_dummy);
 754         max732x_irq_teardown(chip);
 755         return ret;
 756 }
 757
 758 static int max732x_remove(struct i2c_client *client)
 759 {
 760         struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
 761         struct max732x_chip *chip = i2c_get_clientdata(client);
 762
 763         if (pdata && pdata->teardown) {
 764                 int ret;
 765
 766                 ret = pdata->teardown(client, chip->gpio_chip.base,
 767                                 chip->gpio_chip.ngpio, pdata->context);
 768                 if (ret < 0) {
 769                         dev_err(&client->dev, "%s failed, %d\n",
 770                                         "teardown", ret);
 771                         return ret;
 772                 }
 773         }
 774
 775         gpiochip_remove(&chip->gpio_chip);
 776
 777         max732x_irq_teardown(chip);
 778
 779         /* unregister any dummy i2c_client */
 780         if (chip->client_dummy)
 781                 i2c_unregister_device(chip->client_dummy);
 782
 783         return 0;
 784 }
 785
 786 static struct i2c_driver max732x_driver = {
 787         .driver = {
 788                 .name           = "max732x",
 789                 .owner          = THIS_MODULE,
 790                 .of_match_table = of_match_ptr(max732x_of_table),
 791         },
 792         .probe          = max732x_probe,
 793         .remove         = max732x_remove,
 794         .id_table       = max732x_id,
 795 };
 796
 797 static int __init max732x_init(void)
 798 {
 799         return i2c_add_driver(&max732x_driver);
 800 }
 801 /* register after i2c postcore initcall and before
 802  * subsys initcalls that may rely on these GPIOs
 803  */
 804 subsys_initcall(max732x_init);
 805
 806 static void __exit max732x_exit(void)
 807 {
 808         i2c_del_driver(&max732x_driver);
 809 }
 810 module_exit(max732x_exit);
 811
 812 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
 813 MODULE_DESCRIPTION("GPIO expander driver for MAX732X");
 814 MODULE_LICENSE("GPL");