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), ®_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 int max732x_irq_set_wake(struct irq_data *data, unsigned int on) 433 { 434 struct max732x_chip *chip = irq_data_get_irq_chip_data(data); 435 436 irq_set_irq_wake(chip->client->irq, on); 437 return 0; 438 } 439 440 static struct irq_chip max732x_irq_chip = { 441 .name = "max732x", 442 .irq_mask = max732x_irq_mask, 443 .irq_unmask = max732x_irq_unmask, 444 .irq_bus_lock = max732x_irq_bus_lock, 445 .irq_bus_sync_unlock = max732x_irq_bus_sync_unlock, 446 .irq_set_type = max732x_irq_set_type, 447 .irq_set_wake = max732x_irq_set_wake, 448 }; 449 450 static uint8_t max732x_irq_pending(struct max732x_chip *chip) 451 { 452 uint8_t cur_stat; 453 uint8_t old_stat; 454 uint8_t trigger; 455 uint8_t pending; 456 uint16_t status; 457 int ret; 458 459 ret = max732x_readw(chip, &status); 460 if (ret) 461 return 0; 462 463 trigger = status >> 8; 464 trigger &= chip->irq_mask; 465 466 if (!trigger) 467 return 0; 468 469 cur_stat = status & 0xFF; 470 cur_stat &= chip->irq_mask; 471 472 old_stat = cur_stat ^ trigger; 473 474 pending = (old_stat & chip->irq_trig_fall) | 475 (cur_stat & chip->irq_trig_raise); 476 pending &= trigger; 477 478 return pending; 479 } 480 481 static irqreturn_t max732x_irq_handler(int irq, void *devid) 482 { 483 struct max732x_chip *chip = devid; 484 uint8_t pending; 485 uint8_t level; 486 487 pending = max732x_irq_pending(chip); 488 489 if (!pending) 490 return IRQ_HANDLED; 491 492 do { 493 level = __ffs(pending); 494 handle_nested_irq(irq_find_mapping(chip->gpio_chip.irqdomain, 495 level)); 496 497 pending &= ~(1 << level); 498 } while (pending); 499 500 return IRQ_HANDLED; 501 } 502 503 static int max732x_irq_setup(struct max732x_chip *chip, 504 const struct i2c_device_id *id) 505 { 506 struct i2c_client *client = chip->client; 507 struct max732x_platform_data *pdata = dev_get_platdata(&client->dev); 508 int has_irq = max732x_features[id->driver_data] >> 32; 509 int irq_base = 0; 510 int ret; 511 512 if (((pdata && pdata->irq_base) || client->irq) 513 && has_irq != INT_NONE) { 514 if (pdata) 515 irq_base = pdata->irq_base; 516 chip->irq_features = has_irq; 517 mutex_init(&chip->irq_lock); 518 519 ret = devm_request_threaded_irq(&client->dev, client->irq, 520 NULL, max732x_irq_handler, IRQF_ONESHOT | 521 IRQF_TRIGGER_FALLING | IRQF_SHARED, 522 dev_name(&client->dev), chip); 523 if (ret) { 524 dev_err(&client->dev, "failed to request irq %d\n", 525 client->irq); 526 return ret; 527 } 528 ret = gpiochip_irqchip_add(&chip->gpio_chip, 529 &max732x_irq_chip, 530 irq_base, 531 handle_simple_irq, 532 IRQ_TYPE_NONE); 533 if (ret) { 534 dev_err(&client->dev, 535 "could not connect irqchip to gpiochip\n"); 536 return ret; 537 } 538 gpiochip_set_chained_irqchip(&chip->gpio_chip, 539 &max732x_irq_chip, 540 client->irq, 541 NULL); 542 } 543 544 return 0; 545 } 546 547 #else /* CONFIG_GPIO_MAX732X_IRQ */ 548 static int max732x_irq_setup(struct max732x_chip *chip, 549 const struct i2c_device_id *id) 550 { 551 struct i2c_client *client = chip->client; 552 struct max732x_platform_data *pdata = dev_get_platdata(&client->dev); 553 int has_irq = max732x_features[id->driver_data] >> 32; 554 555 if (((pdata && pdata->irq_base) || client->irq) && has_irq != INT_NONE) 556 dev_warn(&client->dev, "interrupt support not compiled in\n"); 557 558 return 0; 559 } 560 #endif 561 562 static int max732x_setup_gpio(struct max732x_chip *chip, 563 const struct i2c_device_id *id, 564 unsigned gpio_start) 565 { 566 struct gpio_chip *gc = &chip->gpio_chip; 567 uint32_t id_data = (uint32_t)max732x_features[id->driver_data]; 568 int i, port = 0; 569 570 for (i = 0; i < 16; i++, id_data >>= 2) { 571 unsigned int mask = 1 << port; 572 573 switch (id_data & 0x3) { 574 case PORT_OUTPUT: 575 chip->dir_output |= mask; 576 break; 577 case PORT_INPUT: 578 chip->dir_input |= mask; 579 break; 580 case PORT_OPENDRAIN: 581 chip->dir_output |= mask; 582 chip->dir_input |= mask; 583 break; 584 default: 585 continue; 586 } 587 588 if (i < 8) 589 chip->mask_group_a |= mask; 590 port++; 591 } 592 593 if (chip->dir_input) 594 gc->direction_input = max732x_gpio_direction_input; 595 if (chip->dir_output) { 596 gc->direction_output = max732x_gpio_direction_output; 597 gc->set = max732x_gpio_set_value; 598 gc->set_multiple = max732x_gpio_set_multiple; 599 } 600 gc->get = max732x_gpio_get_value; 601 gc->can_sleep = true; 602 603 gc->base = gpio_start; 604 gc->ngpio = port; 605 gc->label = chip->client->name; 606 gc->owner = THIS_MODULE; 607 608 return port; 609 } 610 611 static struct max732x_platform_data *of_gpio_max732x(struct device *dev) 612 { 613 struct max732x_platform_data *pdata; 614 615 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); 616 if (!pdata) 617 return NULL; 618 619 pdata->gpio_base = -1; 620 621 return pdata; 622 } 623 624 static int max732x_probe(struct i2c_client *client, 625 const struct i2c_device_id *id) 626 { 627 struct max732x_platform_data *pdata; 628 struct device_node *node; 629 struct max732x_chip *chip; 630 struct i2c_client *c; 631 uint16_t addr_a, addr_b; 632 int ret, nr_port; 633 634 pdata = dev_get_platdata(&client->dev); 635 node = client->dev.of_node; 636 637 if (!pdata && node) 638 pdata = of_gpio_max732x(&client->dev); 639 640 if (!pdata) { 641 dev_dbg(&client->dev, "no platform data\n"); 642 return -EINVAL; 643 } 644 645 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); 646 if (chip == NULL) 647 return -ENOMEM; 648 chip->client = client; 649 650 nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base); 651 chip->gpio_chip.dev = &client->dev; 652 653 addr_a = (client->addr & 0x0f) | 0x60; 654 addr_b = (client->addr & 0x0f) | 0x50; 655 656 switch (client->addr & 0x70) { 657 case 0x60: 658 chip->client_group_a = client; 659 if (nr_port > 8) { 660 c = i2c_new_dummy(client->adapter, addr_b); 661 chip->client_group_b = chip->client_dummy = c; 662 } 663 break; 664 case 0x50: 665 chip->client_group_b = client; 666 if (nr_port > 8) { 667 c = i2c_new_dummy(client->adapter, addr_a); 668 chip->client_group_a = chip->client_dummy = c; 669 } 670 break; 671 default: 672 dev_err(&client->dev, "invalid I2C address specified %02x\n", 673 client->addr); 674 ret = -EINVAL; 675 goto out_failed; 676 } 677 678 if (nr_port > 8 && !chip->client_dummy) { 679 dev_err(&client->dev, 680 "Failed to allocate second group I2C device\n"); 681 ret = -ENODEV; 682 goto out_failed; 683 } 684 685 mutex_init(&chip->lock); 686 687 max732x_readb(chip, is_group_a(chip, 0), &chip->reg_out[0]); 688 if (nr_port > 8) 689 max732x_readb(chip, is_group_a(chip, 8), &chip->reg_out[1]); 690 691 ret = gpiochip_add(&chip->gpio_chip); 692 if (ret) 693 goto out_failed; 694 695 ret = max732x_irq_setup(chip, id); 696 if (ret) { 697 gpiochip_remove(&chip->gpio_chip); 698 goto out_failed; 699 } 700 701 if (pdata && pdata->setup) { 702 ret = pdata->setup(client, chip->gpio_chip.base, 703 chip->gpio_chip.ngpio, pdata->context); 704 if (ret < 0) 705 dev_warn(&client->dev, "setup failed, %d\n", ret); 706 } 707 708 i2c_set_clientdata(client, chip); 709 return 0; 710 711 out_failed: 712 if (chip->client_dummy) 713 i2c_unregister_device(chip->client_dummy); 714 return ret; 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 gpiochip_remove(&chip->gpio_chip); 735 736 /* unregister any dummy i2c_client */ 737 if (chip->client_dummy) 738 i2c_unregister_device(chip->client_dummy); 739 740 return 0; 741 } 742 743 static struct i2c_driver max732x_driver = { 744 .driver = { 745 .name = "max732x", 746 .owner = THIS_MODULE, 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"); 772