1// SPDX-License-Identifier: GPL-2.0 2/* 3 * I2C multiplexer 4 * 5 * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it> 6 * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it> 7 * 8 * This module supports the PCA954x and PCA984x series of I2C multiplexer/switch 9 * chips made by NXP Semiconductors. 10 * This includes the: 11 * PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547, 12 * PCA9548, PCA9846, PCA9847, PCA9848 and PCA9849. 13 * 14 * It's also compatible to Maxims MAX735x I2C switch chips, which are controlled 15 * as the NXP PCA9548 and the MAX736x chips that act like the PCA9544. 16 * 17 * This includes the: 18 * MAX7356, MAX7357, MAX7358, MAX7367, MAX7368 and MAX7369 19 * 20 * These chips are all controlled via the I2C bus itself, and all have a 21 * single 8-bit register. The upstream "parent" bus fans out to two, 22 * four, or eight downstream busses or channels; which of these 23 * are selected is determined by the chip type and register contents. A 24 * mux can select only one sub-bus at a time; a switch can select any 25 * combination simultaneously. 26 * 27 * Based on: 28 * pca954x.c from Kumar Gala <galak@kernel.crashing.org> 29 * Copyright (C) 2006 30 * 31 * Based on: 32 * pca954x.c from Ken Harrenstien 33 * Copyright (C) 2004 Google, Inc. (Ken Harrenstien) 34 * 35 * Based on: 36 * i2c-virtual_cb.c from Brian Kuschak <bkuschak@yahoo.com> 37 * and 38 * pca9540.c from Jean Delvare <jdelvare@suse.de>. 39 */ 40 41#include <linux/device.h> 42#include <linux/delay.h> 43#include <linux/gpio/consumer.h> 44#include <linux/i2c.h> 45#include <linux/i2c-mux.h> 46#include <linux/interrupt.h> 47#include <linux/irq.h> 48#include <linux/module.h> 49#include <linux/pm.h> 50#include <linux/property.h> 51#include <linux/regulator/consumer.h> 52#include <linux/reset.h> 53#include <linux/slab.h> 54#include <linux/spinlock.h> 55#include <dt-bindings/mux/mux.h> 56 57#define PCA954X_MAX_NCHANS 8 58 59#define PCA954X_IRQ_OFFSET 4 60 61/* 62 * MAX7357's configuration register is writeable after POR, but 63 * can be locked by setting the basic mode bit. MAX7358 configuration 64 * register is locked by default and needs to be unlocked first. 65 * The configuration register holds the following settings: 66 */ 67#define MAX7357_CONF_INT_ENABLE BIT(0) 68#define MAX7357_CONF_FLUSH_OUT BIT(1) 69#define MAX7357_CONF_RELEASE_INT BIT(2) 70#define MAX7357_CONF_DISCON_SINGLE_CHAN BIT(4) 71#define MAX7357_CONF_PRECONNECT_TEST BIT(7) 72 73#define MAX7357_POR_DEFAULT_CONF MAX7357_CONF_INT_ENABLE 74 75enum pca_type { 76 max_7356, 77 max_7357, 78 max_7358, 79 max_7367, 80 max_7368, 81 max_7369, 82 pca_9540, 83 pca_9542, 84 pca_9543, 85 pca_9544, 86 pca_9545, 87 pca_9546, 88 pca_9547, 89 pca_9548, 90 pca_9846, 91 pca_9847, 92 pca_9848, 93 pca_9849, 94}; 95 96struct chip_desc { 97 u8 nchans; 98 u8 enable; /* used for muxes only */ 99 u8 has_irq; 100 enum muxtype { 101 pca954x_ismux = 0, 102 pca954x_isswi 103 } muxtype; 104 struct i2c_device_identity id; 105}; 106 107struct pca954x { 108 const struct chip_desc *chip; 109 110 u8 last_chan; /* last register value */ 111 /* MUX_IDLE_AS_IS, MUX_IDLE_DISCONNECT or >= 0 for channel */ 112 s32 idle_state; 113 114 struct i2c_client *client; 115 116 struct irq_domain *irq; 117 unsigned int irq_mask; 118 raw_spinlock_t lock; 119 struct regulator *supply; 120 121 struct gpio_desc *reset_gpio; 122 struct reset_control *reset_cont; 123}; 124 125/* Provide specs for the MAX735x, PCA954x and PCA984x types we know about */ 126static const struct chip_desc chips[] = { 127 [max_7356] = { 128 .nchans = 8, 129 .muxtype = pca954x_isswi, 130 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE }, 131 }, 132 [max_7357] = { 133 .nchans = 8, 134 .muxtype = pca954x_isswi, 135 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE }, 136 /* 137 * No interrupt controller support. The interrupt 138 * provides information about stuck channels. 139 */ 140 }, 141 [max_7358] = { 142 .nchans = 8, 143 .muxtype = pca954x_isswi, 144 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE }, 145 /* 146 * No interrupt controller support. The interrupt 147 * provides information about stuck channels. 148 */ 149 }, 150 [max_7367] = { 151 .nchans = 4, 152 .muxtype = pca954x_isswi, 153 .has_irq = 1, 154 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE }, 155 }, 156 [max_7368] = { 157 .nchans = 4, 158 .muxtype = pca954x_isswi, 159 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE }, 160 }, 161 [max_7369] = { 162 .nchans = 4, 163 .enable = 0x4, 164 .muxtype = pca954x_ismux, 165 .has_irq = 1, 166 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE }, 167 }, 168 [pca_9540] = { 169 .nchans = 2, 170 .enable = 0x4, 171 .muxtype = pca954x_ismux, 172 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE }, 173 }, 174 [pca_9542] = { 175 .nchans = 2, 176 .enable = 0x4, 177 .has_irq = 1, 178 .muxtype = pca954x_ismux, 179 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE }, 180 }, 181 [pca_9543] = { 182 .nchans = 2, 183 .has_irq = 1, 184 .muxtype = pca954x_isswi, 185 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE }, 186 }, 187 [pca_9544] = { 188 .nchans = 4, 189 .enable = 0x4, 190 .has_irq = 1, 191 .muxtype = pca954x_ismux, 192 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE }, 193 }, 194 [pca_9545] = { 195 .nchans = 4, 196 .has_irq = 1, 197 .muxtype = pca954x_isswi, 198 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE }, 199 }, 200 [pca_9546] = { 201 .nchans = 4, 202 .muxtype = pca954x_isswi, 203 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE }, 204 }, 205 [pca_9547] = { 206 .nchans = 8, 207 .enable = 0x8, 208 .muxtype = pca954x_ismux, 209 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE }, 210 }, 211 [pca_9548] = { 212 .nchans = 8, 213 .muxtype = pca954x_isswi, 214 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE }, 215 }, 216 [pca_9846] = { 217 .nchans = 4, 218 .muxtype = pca954x_isswi, 219 .id = { 220 .manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS, 221 .part_id = 0x10b, 222 }, 223 }, 224 [pca_9847] = { 225 .nchans = 8, 226 .enable = 0x8, 227 .muxtype = pca954x_ismux, 228 .id = { 229 .manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS, 230 .part_id = 0x108, 231 }, 232 }, 233 [pca_9848] = { 234 .nchans = 8, 235 .muxtype = pca954x_isswi, 236 .id = { 237 .manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS, 238 .part_id = 0x10a, 239 }, 240 }, 241 [pca_9849] = { 242 .nchans = 4, 243 .enable = 0x4, 244 .muxtype = pca954x_ismux, 245 .id = { 246 .manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS, 247 .part_id = 0x109, 248 }, 249 }, 250}; 251 252static const struct i2c_device_id pca954x_id[] = { 253 { "max7356", max_7356 }, 254 { "max7357", max_7357 }, 255 { "max7358", max_7358 }, 256 { "max7367", max_7367 }, 257 { "max7368", max_7368 }, 258 { "max7369", max_7369 }, 259 { "pca9540", pca_9540 }, 260 { "pca9542", pca_9542 }, 261 { "pca9543", pca_9543 }, 262 { "pca9544", pca_9544 }, 263 { "pca9545", pca_9545 }, 264 { "pca9546", pca_9546 }, 265 { "pca9547", pca_9547 }, 266 { "pca9548", pca_9548 }, 267 { "pca9846", pca_9846 }, 268 { "pca9847", pca_9847 }, 269 { "pca9848", pca_9848 }, 270 { "pca9849", pca_9849 }, 271 { } 272}; 273MODULE_DEVICE_TABLE(i2c, pca954x_id); 274 275static const struct of_device_id pca954x_of_match[] = { 276 { .compatible = "maxim,max7356", .data = &chips[max_7356] }, 277 { .compatible = "maxim,max7357", .data = &chips[max_7357] }, 278 { .compatible = "maxim,max7358", .data = &chips[max_7358] }, 279 { .compatible = "maxim,max7367", .data = &chips[max_7367] }, 280 { .compatible = "maxim,max7368", .data = &chips[max_7368] }, 281 { .compatible = "maxim,max7369", .data = &chips[max_7369] }, 282 { .compatible = "nxp,pca9540", .data = &chips[pca_9540] }, 283 { .compatible = "nxp,pca9542", .data = &chips[pca_9542] }, 284 { .compatible = "nxp,pca9543", .data = &chips[pca_9543] }, 285 { .compatible = "nxp,pca9544", .data = &chips[pca_9544] }, 286 { .compatible = "nxp,pca9545", .data = &chips[pca_9545] }, 287 { .compatible = "nxp,pca9546", .data = &chips[pca_9546] }, 288 { .compatible = "nxp,pca9547", .data = &chips[pca_9547] }, 289 { .compatible = "nxp,pca9548", .data = &chips[pca_9548] }, 290 { .compatible = "nxp,pca9846", .data = &chips[pca_9846] }, 291 { .compatible = "nxp,pca9847", .data = &chips[pca_9847] }, 292 { .compatible = "nxp,pca9848", .data = &chips[pca_9848] }, 293 { .compatible = "nxp,pca9849", .data = &chips[pca_9849] }, 294 {} 295}; 296MODULE_DEVICE_TABLE(of, pca954x_of_match); 297 298/* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer() 299 for this as they will try to lock adapter a second time */ 300static int pca954x_reg_write(struct i2c_adapter *adap, 301 struct i2c_client *client, u8 val) 302{ 303 union i2c_smbus_data dummy; 304 305 return __i2c_smbus_xfer(adap, client->addr, client->flags, 306 I2C_SMBUS_WRITE, val, 307 I2C_SMBUS_BYTE, &dummy); 308} 309 310static u8 pca954x_regval(struct pca954x *data, u8 chan) 311{ 312 /* We make switches look like muxes, not sure how to be smarter. */ 313 if (data->chip->muxtype == pca954x_ismux) 314 return chan | data->chip->enable; 315 else 316 return 1 << chan; 317} 318 319static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan) 320{ 321 struct pca954x *data = i2c_mux_priv(muxc); 322 struct i2c_client *client = data->client; 323 u8 regval; 324 int ret = 0; 325 326 regval = pca954x_regval(data, chan); 327 /* Only select the channel if its different from the last channel */ 328 if (data->last_chan != regval) { 329 ret = pca954x_reg_write(muxc->parent, client, regval); 330 data->last_chan = ret < 0 ? 0 : regval; 331 } 332 333 return ret; 334} 335 336static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan) 337{ 338 struct pca954x *data = i2c_mux_priv(muxc); 339 struct i2c_client *client = data->client; 340 s32 idle_state; 341 342 idle_state = READ_ONCE(data->idle_state); 343 if (idle_state >= 0) 344 /* Set the mux back to a predetermined channel */ 345 return pca954x_select_chan(muxc, idle_state); 346 347 if (idle_state == MUX_IDLE_DISCONNECT) { 348 /* Deselect active channel */ 349 data->last_chan = 0; 350 return pca954x_reg_write(muxc->parent, client, 351 data->last_chan); 352 } 353 354 /* otherwise leave as-is */ 355 356 return 0; 357} 358 359static ssize_t idle_state_show(struct device *dev, 360 struct device_attribute *attr, 361 char *buf) 362{ 363 struct i2c_client *client = to_i2c_client(dev); 364 struct i2c_mux_core *muxc = i2c_get_clientdata(client); 365 struct pca954x *data = i2c_mux_priv(muxc); 366 367 return sprintf(buf, "%d\n", READ_ONCE(data->idle_state)); 368} 369 370static ssize_t idle_state_store(struct device *dev, 371 struct device_attribute *attr, 372 const char *buf, size_t count) 373{ 374 struct i2c_client *client = to_i2c_client(dev); 375 struct i2c_mux_core *muxc = i2c_get_clientdata(client); 376 struct pca954x *data = i2c_mux_priv(muxc); 377 int val; 378 int ret; 379 380 ret = kstrtoint(buf, 0, &val); 381 if (ret < 0) 382 return ret; 383 384 if (val != MUX_IDLE_AS_IS && val != MUX_IDLE_DISCONNECT && 385 (val < 0 || val >= data->chip->nchans)) 386 return -EINVAL; 387 388 i2c_lock_bus(muxc->parent, I2C_LOCK_SEGMENT); 389 390 WRITE_ONCE(data->idle_state, val); 391 /* 392 * Set the mux into a state consistent with the new 393 * idle_state. 394 */ 395 if (data->last_chan || val != MUX_IDLE_DISCONNECT) 396 ret = pca954x_deselect_mux(muxc, 0); 397 398 i2c_unlock_bus(muxc->parent, I2C_LOCK_SEGMENT); 399 400 return ret < 0 ? ret : count; 401} 402 403static DEVICE_ATTR_RW(idle_state); 404 405static irqreturn_t pca954x_irq_handler(int irq, void *dev_id) 406{ 407 struct pca954x *data = dev_id; 408 unsigned long pending; 409 int ret, i; 410 411 ret = i2c_smbus_read_byte(data->client); 412 if (ret < 0) 413 return IRQ_NONE; 414 415 pending = (ret >> PCA954X_IRQ_OFFSET) & (BIT(data->chip->nchans) - 1); 416 for_each_set_bit(i, &pending, data->chip->nchans) 417 handle_nested_irq(irq_linear_revmap(data->irq, i)); 418 419 return IRQ_RETVAL(pending); 420} 421 422static int pca954x_irq_set_type(struct irq_data *idata, unsigned int type) 423{ 424 if ((type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_LEVEL_LOW) 425 return -EINVAL; 426 return 0; 427} 428 429static struct irq_chip pca954x_irq_chip = { 430 .name = "i2c-mux-pca954x", 431 .irq_set_type = pca954x_irq_set_type, 432}; 433 434static int pca954x_irq_setup(struct i2c_mux_core *muxc) 435{ 436 struct pca954x *data = i2c_mux_priv(muxc); 437 struct i2c_client *client = data->client; 438 int c, irq; 439 440 if (!data->chip->has_irq || client->irq <= 0) 441 return 0; 442 443 raw_spin_lock_init(&data->lock); 444 445 data->irq = irq_domain_add_linear(client->dev.of_node, 446 data->chip->nchans, 447 &irq_domain_simple_ops, data); 448 if (!data->irq) 449 return -ENODEV; 450 451 for (c = 0; c < data->chip->nchans; c++) { 452 irq = irq_create_mapping(data->irq, c); 453 if (!irq) { 454 dev_err(&client->dev, "failed irq create map\n"); 455 return -EINVAL; 456 } 457 irq_set_chip_data(irq, data); 458 irq_set_chip_and_handler(irq, &pca954x_irq_chip, 459 handle_simple_irq); 460 } 461 462 return 0; 463} 464 465static void pca954x_cleanup(struct i2c_mux_core *muxc) 466{ 467 struct pca954x *data = i2c_mux_priv(muxc); 468 int c, irq; 469 470 regulator_disable(data->supply); 471 472 if (data->irq) { 473 for (c = 0; c < data->chip->nchans; c++) { 474 irq = irq_find_mapping(data->irq, c); 475 irq_dispose_mapping(irq); 476 } 477 irq_domain_remove(data->irq); 478 } 479 i2c_mux_del_adapters(muxc); 480} 481 482static int pca954x_init(struct i2c_client *client, struct pca954x *data) 483{ 484 int ret; 485 486 if (data->idle_state >= 0) 487 data->last_chan = pca954x_regval(data, data->idle_state); 488 else 489 data->last_chan = 0; /* Disconnect multiplexer */ 490 491 if (device_is_compatible(&client->dev, "maxim,max7357")) { 492 if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) { 493 u8 conf = MAX7357_POR_DEFAULT_CONF; 494 /* 495 * The interrupt signal is shared with the reset pin. Release the 496 * interrupt after 1.6 seconds to allow using the pin as reset. 497 */ 498 conf |= MAX7357_CONF_RELEASE_INT; 499 500 if (device_property_read_bool(&client->dev, "maxim,isolate-stuck-channel")) 501 conf |= MAX7357_CONF_DISCON_SINGLE_CHAN; 502 if (device_property_read_bool(&client->dev, 503 "maxim,send-flush-out-sequence")) 504 conf |= MAX7357_CONF_FLUSH_OUT; 505 if (device_property_read_bool(&client->dev, 506 "maxim,preconnection-wiggle-test-enable")) 507 conf |= MAX7357_CONF_PRECONNECT_TEST; 508 509 ret = i2c_smbus_write_byte_data(client, data->last_chan, conf); 510 } else { 511 dev_warn(&client->dev, "Write byte data not supported." 512 "Cannot enable enhanced mode features\n"); 513 ret = i2c_smbus_write_byte(client, data->last_chan); 514 } 515 } else { 516 ret = i2c_smbus_write_byte(client, data->last_chan); 517 } 518 519 if (ret < 0) 520 data->last_chan = 0; 521 522 return ret; 523} 524 525static int pca954x_get_reset(struct device *dev, struct pca954x *data) 526{ 527 data->reset_cont = devm_reset_control_get_optional_shared(dev, NULL); 528 if (IS_ERR(data->reset_cont)) 529 return dev_err_probe(dev, PTR_ERR(data->reset_cont), 530 "Failed to get reset\n"); 531 else if (data->reset_cont) 532 return 0; 533 534 /* 535 * fallback to legacy reset-gpios 536 */ 537 data->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); 538 if (IS_ERR(data->reset_gpio)) { 539 return dev_err_probe(dev, PTR_ERR(data->reset_gpio), 540 "Failed to get reset gpio"); 541 } 542 543 return 0; 544} 545 546static void pca954x_reset_deassert(struct pca954x *data) 547{ 548 if (data->reset_cont) 549 reset_control_deassert(data->reset_cont); 550 else 551 gpiod_set_value_cansleep(data->reset_gpio, 0); 552} 553 554/* 555 * I2C init/probing/exit functions 556 */ 557static int pca954x_probe(struct i2c_client *client) 558{ 559 const struct i2c_device_id *id = i2c_client_get_device_id(client); 560 struct i2c_adapter *adap = client->adapter; 561 struct device *dev = &client->dev; 562 struct i2c_mux_core *muxc; 563 struct pca954x *data; 564 int num; 565 int ret; 566 567 if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE)) 568 return -ENODEV; 569 570 muxc = i2c_mux_alloc(adap, dev, PCA954X_MAX_NCHANS, sizeof(*data), 0, 571 pca954x_select_chan, pca954x_deselect_mux); 572 if (!muxc) 573 return -ENOMEM; 574 data = i2c_mux_priv(muxc); 575 576 i2c_set_clientdata(client, muxc); 577 data->client = client; 578 579 data->supply = devm_regulator_get(dev, "vdd"); 580 if (IS_ERR(data->supply)) 581 return dev_err_probe(dev, PTR_ERR(data->supply), 582 "Failed to request regulator\n"); 583 584 ret = regulator_enable(data->supply); 585 if (ret) 586 return dev_err_probe(dev, ret, 587 "Failed to enable vdd supply\n"); 588 589 ret = pca954x_get_reset(dev, data); 590 if (ret) 591 goto fail_cleanup; 592 593 if (data->reset_cont || data->reset_gpio) { 594 udelay(1); 595 pca954x_reset_deassert(data); 596 /* Give the chip some time to recover. */ 597 udelay(1); 598 } 599 600 data->chip = device_get_match_data(dev); 601 if (!data->chip) 602 data->chip = &chips[id->driver_data]; 603 604 if (data->chip->id.manufacturer_id != I2C_DEVICE_ID_NONE) { 605 struct i2c_device_identity id; 606 607 ret = i2c_get_device_id(client, &id); 608 if (ret && ret != -EOPNOTSUPP) 609 goto fail_cleanup; 610 611 if (!ret && 612 (id.manufacturer_id != data->chip->id.manufacturer_id || 613 id.part_id != data->chip->id.part_id)) { 614 dev_warn(dev, "unexpected device id %03x-%03x-%x\n", 615 id.manufacturer_id, id.part_id, 616 id.die_revision); 617 ret = -ENODEV; 618 goto fail_cleanup; 619 } 620 } 621 622 data->idle_state = MUX_IDLE_AS_IS; 623 if (device_property_read_u32(dev, "idle-state", &data->idle_state)) { 624 if (device_property_read_bool(dev, "i2c-mux-idle-disconnect")) 625 data->idle_state = MUX_IDLE_DISCONNECT; 626 } 627 628 /* 629 * Write the mux register at addr to verify 630 * that the mux is in fact present. This also 631 * initializes the mux to a channel 632 * or disconnected state. 633 */ 634 ret = pca954x_init(client, data); 635 if (ret < 0) { 636 dev_warn(dev, "probe failed\n"); 637 ret = -ENODEV; 638 goto fail_cleanup; 639 } 640 641 ret = pca954x_irq_setup(muxc); 642 if (ret) 643 goto fail_cleanup; 644 645 /* Now create an adapter for each channel */ 646 for (num = 0; num < data->chip->nchans; num++) { 647 ret = i2c_mux_add_adapter(muxc, 0, num, 0); 648 if (ret) 649 goto fail_cleanup; 650 } 651 652 if (data->irq) { 653 ret = devm_request_threaded_irq(dev, data->client->irq, 654 NULL, pca954x_irq_handler, 655 IRQF_ONESHOT | IRQF_SHARED, 656 "pca954x", data); 657 if (ret) 658 goto fail_cleanup; 659 } 660 661 /* 662 * The attr probably isn't going to be needed in most cases, 663 * so don't fail completely on error. 664 */ 665 device_create_file(dev, &dev_attr_idle_state); 666 667 dev_info(dev, "registered %d multiplexed busses for I2C %s %s\n", 668 num, data->chip->muxtype == pca954x_ismux 669 ? "mux" : "switch", client->name); 670 671 return 0; 672 673fail_cleanup: 674 pca954x_cleanup(muxc); 675 return ret; 676} 677 678static void pca954x_remove(struct i2c_client *client) 679{ 680 struct i2c_mux_core *muxc = i2c_get_clientdata(client); 681 682 device_remove_file(&client->dev, &dev_attr_idle_state); 683 684 pca954x_cleanup(muxc); 685} 686 687static int pca954x_resume(struct device *dev) 688{ 689 struct i2c_client *client = to_i2c_client(dev); 690 struct i2c_mux_core *muxc = i2c_get_clientdata(client); 691 struct pca954x *data = i2c_mux_priv(muxc); 692 int ret; 693 694 ret = pca954x_init(client, data); 695 if (ret < 0) 696 dev_err(&client->dev, "failed to verify mux presence\n"); 697 698 return ret; 699} 700 701static DEFINE_SIMPLE_DEV_PM_OPS(pca954x_pm, NULL, pca954x_resume); 702 703static struct i2c_driver pca954x_driver = { 704 .driver = { 705 .name = "pca954x", 706 .pm = pm_sleep_ptr(&pca954x_pm), 707 .of_match_table = pca954x_of_match, 708 }, 709 .probe = pca954x_probe, 710 .remove = pca954x_remove, 711 .id_table = pca954x_id, 712}; 713 714module_i2c_driver(pca954x_driver); 715 716MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>"); 717MODULE_DESCRIPTION("PCA954x I2C mux/switch driver"); 718MODULE_LICENSE("GPL v2"); 719