1 /* 2 * Driver for the Asahi Kasei EMD Corporation AK8974 3 * and Aichi Steel AMI305 magnetometer chips. 4 * Based on a patch from Samu Onkalo and the AK8975 IIO driver. 5 * 6 * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). 7 * Copyright (c) 2010 NVIDIA Corporation. 8 * Copyright (C) 2016 Linaro Ltd. 9 * 10 * Author: Samu Onkalo <samu.p.onkalo@nokia.com> 11 * Author: Linus Walleij <linus.walleij@linaro.org> 12 */ 13 #include <linux/module.h> 14 #include <linux/kernel.h> 15 #include <linux/i2c.h> 16 #include <linux/interrupt.h> 17 #include <linux/irq.h> /* For irq_get_irq_data() */ 18 #include <linux/completion.h> 19 #include <linux/err.h> 20 #include <linux/mutex.h> 21 #include <linux/delay.h> 22 #include <linux/bitops.h> 23 #include <linux/regmap.h> 24 #include <linux/regulator/consumer.h> 25 #include <linux/pm_runtime.h> 26 27 #include <linux/iio/iio.h> 28 #include <linux/iio/sysfs.h> 29 #include <linux/iio/buffer.h> 30 #include <linux/iio/trigger.h> 31 #include <linux/iio/trigger_consumer.h> 32 #include <linux/iio/triggered_buffer.h> 33 34 /* 35 * 16-bit registers are little-endian. LSB is at the address defined below 36 * and MSB is at the next higher address. 37 */ 38 39 /* These registers are common for AK8974 and AMI305 */ 40 #define AK8974_SELFTEST 0x0C 41 #define AK8974_SELFTEST_IDLE 0x55 42 #define AK8974_SELFTEST_OK 0xAA 43 44 #define AK8974_INFO 0x0D 45 46 #define AK8974_WHOAMI 0x0F 47 #define AK8974_WHOAMI_VALUE_AMI305 0x47 48 #define AK8974_WHOAMI_VALUE_AK8974 0x48 49 50 #define AK8974_DATA_X 0x10 51 #define AK8974_DATA_Y 0x12 52 #define AK8974_DATA_Z 0x14 53 #define AK8974_INT_SRC 0x16 54 #define AK8974_STATUS 0x18 55 #define AK8974_INT_CLEAR 0x1A 56 #define AK8974_CTRL1 0x1B 57 #define AK8974_CTRL2 0x1C 58 #define AK8974_CTRL3 0x1D 59 #define AK8974_INT_CTRL 0x1E 60 #define AK8974_INT_THRES 0x26 /* Absolute any axis value threshold */ 61 #define AK8974_PRESET 0x30 62 63 /* AK8974-specific offsets */ 64 #define AK8974_OFFSET_X 0x20 65 #define AK8974_OFFSET_Y 0x22 66 #define AK8974_OFFSET_Z 0x24 67 /* AMI305-specific offsets */ 68 #define AMI305_OFFSET_X 0x6C 69 #define AMI305_OFFSET_Y 0x72 70 #define AMI305_OFFSET_Z 0x78 71 72 /* Different temperature registers */ 73 #define AK8974_TEMP 0x31 74 #define AMI305_TEMP 0x60 75 76 #define AK8974_INT_X_HIGH BIT(7) /* Axis over +threshold */ 77 #define AK8974_INT_Y_HIGH BIT(6) 78 #define AK8974_INT_Z_HIGH BIT(5) 79 #define AK8974_INT_X_LOW BIT(4) /* Axis below -threshold */ 80 #define AK8974_INT_Y_LOW BIT(3) 81 #define AK8974_INT_Z_LOW BIT(2) 82 #define AK8974_INT_RANGE BIT(1) /* Range overflow (any axis) */ 83 84 #define AK8974_STATUS_DRDY BIT(6) /* Data ready */ 85 #define AK8974_STATUS_OVERRUN BIT(5) /* Data overrun */ 86 #define AK8974_STATUS_INT BIT(4) /* Interrupt occurred */ 87 88 #define AK8974_CTRL1_POWER BIT(7) /* 0 = standby; 1 = active */ 89 #define AK8974_CTRL1_RATE BIT(4) /* 0 = 10 Hz; 1 = 20 Hz */ 90 #define AK8974_CTRL1_FORCE_EN BIT(1) /* 0 = normal; 1 = force */ 91 #define AK8974_CTRL1_MODE2 BIT(0) /* 0 */ 92 93 #define AK8974_CTRL2_INT_EN BIT(4) /* 1 = enable interrupts */ 94 #define AK8974_CTRL2_DRDY_EN BIT(3) /* 1 = enable data ready signal */ 95 #define AK8974_CTRL2_DRDY_POL BIT(2) /* 1 = data ready active high */ 96 #define AK8974_CTRL2_RESDEF (AK8974_CTRL2_DRDY_POL) 97 98 #define AK8974_CTRL3_RESET BIT(7) /* Software reset */ 99 #define AK8974_CTRL3_FORCE BIT(6) /* Start forced measurement */ 100 #define AK8974_CTRL3_SELFTEST BIT(4) /* Set selftest register */ 101 #define AK8974_CTRL3_RESDEF 0x00 102 103 #define AK8974_INT_CTRL_XEN BIT(7) /* Enable interrupt for this axis */ 104 #define AK8974_INT_CTRL_YEN BIT(6) 105 #define AK8974_INT_CTRL_ZEN BIT(5) 106 #define AK8974_INT_CTRL_XYZEN (BIT(7)|BIT(6)|BIT(5)) 107 #define AK8974_INT_CTRL_POL BIT(3) /* 0 = active low; 1 = active high */ 108 #define AK8974_INT_CTRL_PULSE BIT(1) /* 0 = latched; 1 = pulse (50 usec) */ 109 #define AK8974_INT_CTRL_RESDEF (AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL) 110 111 /* The AMI305 has elaborate FW version and serial number registers */ 112 #define AMI305_VER 0xE8 113 #define AMI305_SN 0xEA 114 115 #define AK8974_MAX_RANGE 2048 116 117 #define AK8974_POWERON_DELAY 50 118 #define AK8974_ACTIVATE_DELAY 1 119 #define AK8974_SELFTEST_DELAY 1 120 /* 121 * Set the autosuspend to two orders of magnitude larger than the poweron 122 * delay to make sane reasonable power tradeoff savings (5 seconds in 123 * this case). 124 */ 125 #define AK8974_AUTOSUSPEND_DELAY 5000 126 127 #define AK8974_MEASTIME 3 128 129 #define AK8974_PWR_ON 1 130 #define AK8974_PWR_OFF 0 131 132 /** 133 * struct ak8974 - state container for the AK8974 driver 134 * @i2c: parent I2C client 135 * @orientation: mounting matrix, flipped axis etc 136 * @map: regmap to access the AK8974 registers over I2C 137 * @regs: the avdd and dvdd power regulators 138 * @name: the name of the part 139 * @variant: the whoami ID value (for selecting code paths) 140 * @lock: locks the magnetometer for exclusive use during a measurement 141 * @drdy_irq: uses the DRDY IRQ line 142 * @drdy_complete: completion for DRDY 143 * @drdy_active_low: the DRDY IRQ is active low 144 */ 145 struct ak8974 { 146 struct i2c_client *i2c; 147 struct iio_mount_matrix orientation; 148 struct regmap *map; 149 struct regulator_bulk_data regs[2]; 150 const char *name; 151 u8 variant; 152 struct mutex lock; 153 bool drdy_irq; 154 struct completion drdy_complete; 155 bool drdy_active_low; 156 }; 157 158 static const char ak8974_reg_avdd[] = "avdd"; 159 static const char ak8974_reg_dvdd[] = "dvdd"; 160 161 static int ak8974_set_power(struct ak8974 *ak8974, bool mode) 162 { 163 int ret; 164 u8 val; 165 166 val = mode ? AK8974_CTRL1_POWER : 0; 167 val |= AK8974_CTRL1_FORCE_EN; 168 ret = regmap_write(ak8974->map, AK8974_CTRL1, val); 169 if (ret < 0) 170 return ret; 171 172 if (mode) 173 msleep(AK8974_ACTIVATE_DELAY); 174 175 return 0; 176 } 177 178 static int ak8974_reset(struct ak8974 *ak8974) 179 { 180 int ret; 181 182 /* Power on to get register access. Sets CTRL1 reg to reset state */ 183 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 184 if (ret) 185 return ret; 186 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF); 187 if (ret) 188 return ret; 189 ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF); 190 if (ret) 191 return ret; 192 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, 193 AK8974_INT_CTRL_RESDEF); 194 if (ret) 195 return ret; 196 197 /* After reset, power off is default state */ 198 return ak8974_set_power(ak8974, AK8974_PWR_OFF); 199 } 200 201 static int ak8974_configure(struct ak8974 *ak8974) 202 { 203 int ret; 204 205 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN | 206 AK8974_CTRL2_INT_EN); 207 if (ret) 208 return ret; 209 ret = regmap_write(ak8974->map, AK8974_CTRL3, 0); 210 if (ret) 211 return ret; 212 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL); 213 if (ret) 214 return ret; 215 216 return regmap_write(ak8974->map, AK8974_PRESET, 0); 217 } 218 219 static int ak8974_trigmeas(struct ak8974 *ak8974) 220 { 221 unsigned int clear; 222 u8 mask; 223 u8 val; 224 int ret; 225 226 /* Clear any previous measurement overflow status */ 227 ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear); 228 if (ret) 229 return ret; 230 231 /* If we have a DRDY IRQ line, use it */ 232 if (ak8974->drdy_irq) { 233 mask = AK8974_CTRL2_INT_EN | 234 AK8974_CTRL2_DRDY_EN | 235 AK8974_CTRL2_DRDY_POL; 236 val = AK8974_CTRL2_DRDY_EN; 237 238 if (!ak8974->drdy_active_low) 239 val |= AK8974_CTRL2_DRDY_POL; 240 241 init_completion(&ak8974->drdy_complete); 242 ret = regmap_update_bits(ak8974->map, AK8974_CTRL2, 243 mask, val); 244 if (ret) 245 return ret; 246 } 247 248 /* Force a measurement */ 249 return regmap_update_bits(ak8974->map, 250 AK8974_CTRL3, 251 AK8974_CTRL3_FORCE, 252 AK8974_CTRL3_FORCE); 253 } 254 255 static int ak8974_await_drdy(struct ak8974 *ak8974) 256 { 257 int timeout = 2; 258 unsigned int val; 259 int ret; 260 261 if (ak8974->drdy_irq) { 262 ret = wait_for_completion_timeout(&ak8974->drdy_complete, 263 1 + msecs_to_jiffies(1000)); 264 if (!ret) { 265 dev_err(&ak8974->i2c->dev, 266 "timeout waiting for DRDY IRQ\n"); 267 return -ETIMEDOUT; 268 } 269 return 0; 270 } 271 272 /* Default delay-based poll loop */ 273 do { 274 msleep(AK8974_MEASTIME); 275 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 276 if (ret < 0) 277 return ret; 278 if (val & AK8974_STATUS_DRDY) 279 return 0; 280 } while (--timeout); 281 if (!timeout) { 282 dev_err(&ak8974->i2c->dev, 283 "timeout waiting for DRDY\n"); 284 return -ETIMEDOUT; 285 } 286 287 return 0; 288 } 289 290 static int ak8974_getresult(struct ak8974 *ak8974, s16 *result) 291 { 292 unsigned int src; 293 int ret; 294 295 ret = ak8974_await_drdy(ak8974); 296 if (ret) 297 return ret; 298 ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src); 299 if (ret < 0) 300 return ret; 301 302 /* Out of range overflow! Strong magnet close? */ 303 if (src & AK8974_INT_RANGE) { 304 dev_err(&ak8974->i2c->dev, 305 "range overflow in sensor\n"); 306 return -ERANGE; 307 } 308 309 ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6); 310 if (ret) 311 return ret; 312 313 return ret; 314 } 315 316 static irqreturn_t ak8974_drdy_irq(int irq, void *d) 317 { 318 struct ak8974 *ak8974 = d; 319 320 if (!ak8974->drdy_irq) 321 return IRQ_NONE; 322 323 /* TODO: timestamp here to get good measurement stamps */ 324 return IRQ_WAKE_THREAD; 325 } 326 327 static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d) 328 { 329 struct ak8974 *ak8974 = d; 330 unsigned int val; 331 int ret; 332 333 /* Check if this was a DRDY from us */ 334 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 335 if (ret < 0) { 336 dev_err(&ak8974->i2c->dev, "error reading DRDY status\n"); 337 return IRQ_HANDLED; 338 } 339 if (val & AK8974_STATUS_DRDY) { 340 /* Yes this was our IRQ */ 341 complete(&ak8974->drdy_complete); 342 return IRQ_HANDLED; 343 } 344 345 /* We may be on a shared IRQ, let the next client check */ 346 return IRQ_NONE; 347 } 348 349 static int ak8974_selftest(struct ak8974 *ak8974) 350 { 351 struct device *dev = &ak8974->i2c->dev; 352 unsigned int val; 353 int ret; 354 355 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 356 if (ret) 357 return ret; 358 if (val != AK8974_SELFTEST_IDLE) { 359 dev_err(dev, "selftest not idle before test\n"); 360 return -EIO; 361 } 362 363 /* Trigger self-test */ 364 ret = regmap_update_bits(ak8974->map, 365 AK8974_CTRL3, 366 AK8974_CTRL3_SELFTEST, 367 AK8974_CTRL3_SELFTEST); 368 if (ret) { 369 dev_err(dev, "could not write CTRL3\n"); 370 return ret; 371 } 372 373 msleep(AK8974_SELFTEST_DELAY); 374 375 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 376 if (ret) 377 return ret; 378 if (val != AK8974_SELFTEST_OK) { 379 dev_err(dev, "selftest result NOT OK (%02x)\n", val); 380 return -EIO; 381 } 382 383 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 384 if (ret) 385 return ret; 386 if (val != AK8974_SELFTEST_IDLE) { 387 dev_err(dev, "selftest not idle after test (%02x)\n", val); 388 return -EIO; 389 } 390 dev_dbg(dev, "passed self-test\n"); 391 392 return 0; 393 } 394 395 static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val) 396 { 397 int ret; 398 u16 bulk; 399 400 ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2); 401 if (ret) 402 return ret; 403 *val = le16_to_cpu(bulk); 404 405 return 0; 406 } 407 408 static int ak8974_detect(struct ak8974 *ak8974) 409 { 410 unsigned int whoami; 411 const char *name; 412 int ret; 413 unsigned int fw; 414 u16 sn; 415 416 ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami); 417 if (ret) 418 return ret; 419 420 switch (whoami) { 421 case AK8974_WHOAMI_VALUE_AMI305: 422 name = "ami305"; 423 ret = regmap_read(ak8974->map, AMI305_VER, &fw); 424 if (ret) 425 return ret; 426 fw &= 0x7f; /* only bits 0 thru 6 valid */ 427 ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn); 428 if (ret) 429 return ret; 430 dev_info(&ak8974->i2c->dev, 431 "detected %s, FW ver %02x, S/N: %04x\n", 432 name, fw, sn); 433 break; 434 case AK8974_WHOAMI_VALUE_AK8974: 435 name = "ak8974"; 436 dev_info(&ak8974->i2c->dev, "detected AK8974\n"); 437 break; 438 default: 439 dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ", 440 whoami); 441 return -ENODEV; 442 } 443 444 ak8974->name = name; 445 ak8974->variant = whoami; 446 447 return 0; 448 } 449 450 static int ak8974_read_raw(struct iio_dev *indio_dev, 451 struct iio_chan_spec const *chan, 452 int *val, int *val2, 453 long mask) 454 { 455 struct ak8974 *ak8974 = iio_priv(indio_dev); 456 s16 hw_values[3]; 457 int ret = -EINVAL; 458 459 pm_runtime_get_sync(&ak8974->i2c->dev); 460 mutex_lock(&ak8974->lock); 461 462 switch (mask) { 463 case IIO_CHAN_INFO_RAW: 464 if (chan->address > 2) { 465 dev_err(&ak8974->i2c->dev, "faulty channel address\n"); 466 ret = -EIO; 467 goto out_unlock; 468 } 469 ret = ak8974_trigmeas(ak8974); 470 if (ret) 471 goto out_unlock; 472 ret = ak8974_getresult(ak8974, hw_values); 473 if (ret) 474 goto out_unlock; 475 476 /* 477 * We read all axes and discard all but one, for optimized 478 * reading, use the triggered buffer. 479 */ 480 *val = le16_to_cpu(hw_values[chan->address]); 481 482 ret = IIO_VAL_INT; 483 } 484 485 out_unlock: 486 mutex_unlock(&ak8974->lock); 487 pm_runtime_mark_last_busy(&ak8974->i2c->dev); 488 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 489 490 return ret; 491 } 492 493 static void ak8974_fill_buffer(struct iio_dev *indio_dev) 494 { 495 struct ak8974 *ak8974 = iio_priv(indio_dev); 496 int ret; 497 s16 hw_values[8]; /* Three axes + 64bit padding */ 498 499 pm_runtime_get_sync(&ak8974->i2c->dev); 500 mutex_lock(&ak8974->lock); 501 502 ret = ak8974_trigmeas(ak8974); 503 if (ret) { 504 dev_err(&ak8974->i2c->dev, "error triggering measure\n"); 505 goto out_unlock; 506 } 507 ret = ak8974_getresult(ak8974, hw_values); 508 if (ret) { 509 dev_err(&ak8974->i2c->dev, "error getting measures\n"); 510 goto out_unlock; 511 } 512 513 iio_push_to_buffers_with_timestamp(indio_dev, hw_values, 514 iio_get_time_ns(indio_dev)); 515 516 out_unlock: 517 mutex_unlock(&ak8974->lock); 518 pm_runtime_mark_last_busy(&ak8974->i2c->dev); 519 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 520 } 521 522 static irqreturn_t ak8974_handle_trigger(int irq, void *p) 523 { 524 const struct iio_poll_func *pf = p; 525 struct iio_dev *indio_dev = pf->indio_dev; 526 527 ak8974_fill_buffer(indio_dev); 528 iio_trigger_notify_done(indio_dev->trig); 529 530 return IRQ_HANDLED; 531 } 532 533 static const struct iio_mount_matrix * 534 ak8974_get_mount_matrix(const struct iio_dev *indio_dev, 535 const struct iio_chan_spec *chan) 536 { 537 struct ak8974 *ak8974 = iio_priv(indio_dev); 538 539 return &ak8974->orientation; 540 } 541 542 static const struct iio_chan_spec_ext_info ak8974_ext_info[] = { 543 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix), 544 { }, 545 }; 546 547 #define AK8974_AXIS_CHANNEL(axis, index) \ 548 { \ 549 .type = IIO_MAGN, \ 550 .modified = 1, \ 551 .channel2 = IIO_MOD_##axis, \ 552 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 553 .ext_info = ak8974_ext_info, \ 554 .address = index, \ 555 .scan_index = index, \ 556 .scan_type = { \ 557 .sign = 's', \ 558 .realbits = 16, \ 559 .storagebits = 16, \ 560 .endianness = IIO_LE \ 561 }, \ 562 } 563 564 static const struct iio_chan_spec ak8974_channels[] = { 565 AK8974_AXIS_CHANNEL(X, 0), 566 AK8974_AXIS_CHANNEL(Y, 1), 567 AK8974_AXIS_CHANNEL(Z, 2), 568 IIO_CHAN_SOFT_TIMESTAMP(3), 569 }; 570 571 static const unsigned long ak8974_scan_masks[] = { 0x7, 0 }; 572 573 static const struct iio_info ak8974_info = { 574 .read_raw = &ak8974_read_raw, 575 .driver_module = THIS_MODULE, 576 }; 577 578 static bool ak8974_writeable_reg(struct device *dev, unsigned int reg) 579 { 580 struct i2c_client *i2c = to_i2c_client(dev); 581 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 582 struct ak8974 *ak8974 = iio_priv(indio_dev); 583 584 switch (reg) { 585 case AK8974_CTRL1: 586 case AK8974_CTRL2: 587 case AK8974_CTRL3: 588 case AK8974_INT_CTRL: 589 case AK8974_INT_THRES: 590 case AK8974_INT_THRES + 1: 591 case AK8974_PRESET: 592 case AK8974_PRESET + 1: 593 return true; 594 case AK8974_OFFSET_X: 595 case AK8974_OFFSET_X + 1: 596 case AK8974_OFFSET_Y: 597 case AK8974_OFFSET_Y + 1: 598 case AK8974_OFFSET_Z: 599 case AK8974_OFFSET_Z + 1: 600 if (ak8974->variant == AK8974_WHOAMI_VALUE_AK8974) 601 return true; 602 return false; 603 case AMI305_OFFSET_X: 604 case AMI305_OFFSET_X + 1: 605 case AMI305_OFFSET_Y: 606 case AMI305_OFFSET_Y + 1: 607 case AMI305_OFFSET_Z: 608 case AMI305_OFFSET_Z + 1: 609 if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI305) 610 return true; 611 return false; 612 default: 613 return false; 614 } 615 } 616 617 static const struct regmap_config ak8974_regmap_config = { 618 .reg_bits = 8, 619 .val_bits = 8, 620 .max_register = 0xff, 621 .writeable_reg = ak8974_writeable_reg, 622 }; 623 624 static int ak8974_probe(struct i2c_client *i2c, 625 const struct i2c_device_id *id) 626 { 627 struct iio_dev *indio_dev; 628 struct ak8974 *ak8974; 629 unsigned long irq_trig; 630 int irq = i2c->irq; 631 int ret; 632 633 /* Register with IIO */ 634 indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974)); 635 if (indio_dev == NULL) 636 return -ENOMEM; 637 638 ak8974 = iio_priv(indio_dev); 639 i2c_set_clientdata(i2c, indio_dev); 640 ak8974->i2c = i2c; 641 mutex_init(&ak8974->lock); 642 643 ret = of_iio_read_mount_matrix(&i2c->dev, 644 "mount-matrix", 645 &ak8974->orientation); 646 if (ret) 647 return ret; 648 649 ak8974->regs[0].supply = ak8974_reg_avdd; 650 ak8974->regs[1].supply = ak8974_reg_dvdd; 651 652 ret = devm_regulator_bulk_get(&i2c->dev, 653 ARRAY_SIZE(ak8974->regs), 654 ak8974->regs); 655 if (ret < 0) { 656 dev_err(&i2c->dev, "cannot get regulators\n"); 657 return ret; 658 } 659 660 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 661 if (ret < 0) { 662 dev_err(&i2c->dev, "cannot enable regulators\n"); 663 return ret; 664 } 665 666 /* Take runtime PM online */ 667 pm_runtime_get_noresume(&i2c->dev); 668 pm_runtime_set_active(&i2c->dev); 669 pm_runtime_enable(&i2c->dev); 670 671 ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config); 672 if (IS_ERR(ak8974->map)) { 673 dev_err(&i2c->dev, "failed to allocate register map\n"); 674 return PTR_ERR(ak8974->map); 675 } 676 677 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 678 if (ret) { 679 dev_err(&i2c->dev, "could not power on\n"); 680 goto power_off; 681 } 682 683 ret = ak8974_detect(ak8974); 684 if (ret) { 685 dev_err(&i2c->dev, "neither AK8974 nor AMI305 found\n"); 686 goto power_off; 687 } 688 689 ret = ak8974_selftest(ak8974); 690 if (ret) 691 dev_err(&i2c->dev, "selftest failed (continuing anyway)\n"); 692 693 ret = ak8974_reset(ak8974); 694 if (ret) { 695 dev_err(&i2c->dev, "AK8974 reset failed\n"); 696 goto power_off; 697 } 698 699 pm_runtime_set_autosuspend_delay(&i2c->dev, 700 AK8974_AUTOSUSPEND_DELAY); 701 pm_runtime_use_autosuspend(&i2c->dev); 702 pm_runtime_put(&i2c->dev); 703 704 indio_dev->dev.parent = &i2c->dev; 705 indio_dev->channels = ak8974_channels; 706 indio_dev->num_channels = ARRAY_SIZE(ak8974_channels); 707 indio_dev->info = &ak8974_info; 708 indio_dev->available_scan_masks = ak8974_scan_masks; 709 indio_dev->modes = INDIO_DIRECT_MODE; 710 indio_dev->name = ak8974->name; 711 712 ret = iio_triggered_buffer_setup(indio_dev, NULL, 713 ak8974_handle_trigger, 714 NULL); 715 if (ret) { 716 dev_err(&i2c->dev, "triggered buffer setup failed\n"); 717 goto disable_pm; 718 } 719 720 /* If we have a valid DRDY IRQ, make use of it */ 721 if (irq > 0) { 722 irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq)); 723 if (irq_trig == IRQF_TRIGGER_RISING) { 724 dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n"); 725 } else if (irq_trig == IRQF_TRIGGER_FALLING) { 726 ak8974->drdy_active_low = true; 727 dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n"); 728 } else { 729 irq_trig = IRQF_TRIGGER_RISING; 730 } 731 irq_trig |= IRQF_ONESHOT; 732 irq_trig |= IRQF_SHARED; 733 734 ret = devm_request_threaded_irq(&i2c->dev, 735 irq, 736 ak8974_drdy_irq, 737 ak8974_drdy_irq_thread, 738 irq_trig, 739 ak8974->name, 740 ak8974); 741 if (ret) { 742 dev_err(&i2c->dev, "unable to request DRDY IRQ " 743 "- proceeding without IRQ\n"); 744 goto no_irq; 745 } 746 ak8974->drdy_irq = true; 747 } 748 749 no_irq: 750 ret = iio_device_register(indio_dev); 751 if (ret) { 752 dev_err(&i2c->dev, "device register failed\n"); 753 goto cleanup_buffer; 754 } 755 756 return 0; 757 758 cleanup_buffer: 759 iio_triggered_buffer_cleanup(indio_dev); 760 disable_pm: 761 pm_runtime_put_noidle(&i2c->dev); 762 pm_runtime_disable(&i2c->dev); 763 ak8974_set_power(ak8974, AK8974_PWR_OFF); 764 power_off: 765 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 766 767 return ret; 768 } 769 770 static int __exit ak8974_remove(struct i2c_client *i2c) 771 { 772 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 773 struct ak8974 *ak8974 = iio_priv(indio_dev); 774 775 iio_device_unregister(indio_dev); 776 iio_triggered_buffer_cleanup(indio_dev); 777 pm_runtime_get_sync(&i2c->dev); 778 pm_runtime_put_noidle(&i2c->dev); 779 pm_runtime_disable(&i2c->dev); 780 ak8974_set_power(ak8974, AK8974_PWR_OFF); 781 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 782 783 return 0; 784 } 785 786 static int __maybe_unused ak8974_runtime_suspend(struct device *dev) 787 { 788 struct ak8974 *ak8974 = 789 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 790 791 ak8974_set_power(ak8974, AK8974_PWR_OFF); 792 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 793 794 return 0; 795 } 796 797 static int __maybe_unused ak8974_runtime_resume(struct device *dev) 798 { 799 struct ak8974 *ak8974 = 800 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 801 int ret; 802 803 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 804 if (ret) 805 return ret; 806 msleep(AK8974_POWERON_DELAY); 807 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 808 if (ret) 809 goto out_regulator_disable; 810 811 ret = ak8974_configure(ak8974); 812 if (ret) 813 goto out_disable_power; 814 815 return 0; 816 817 out_disable_power: 818 ak8974_set_power(ak8974, AK8974_PWR_OFF); 819 out_regulator_disable: 820 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 821 822 return ret; 823 } 824 825 static const struct dev_pm_ops ak8974_dev_pm_ops = { 826 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, 827 pm_runtime_force_resume) 828 SET_RUNTIME_PM_OPS(ak8974_runtime_suspend, 829 ak8974_runtime_resume, NULL) 830 }; 831 832 static const struct i2c_device_id ak8974_id[] = { 833 {"ami305", 0 }, 834 {"ak8974", 0 }, 835 {} 836 }; 837 MODULE_DEVICE_TABLE(i2c, ak8974_id); 838 839 static const struct of_device_id ak8974_of_match[] = { 840 { .compatible = "asahi-kasei,ak8974", }, 841 {} 842 }; 843 MODULE_DEVICE_TABLE(of, ak8974_of_match); 844 845 static struct i2c_driver ak8974_driver = { 846 .driver = { 847 .name = "ak8974", 848 .pm = &ak8974_dev_pm_ops, 849 .of_match_table = of_match_ptr(ak8974_of_match), 850 }, 851 .probe = ak8974_probe, 852 .remove = __exit_p(ak8974_remove), 853 .id_table = ak8974_id, 854 }; 855 module_i2c_driver(ak8974_driver); 856 857 MODULE_DESCRIPTION("AK8974 and AMI305 3-axis magnetometer driver"); 858 MODULE_AUTHOR("Samu Onkalo"); 859 MODULE_AUTHOR("Linus Walleij"); 860 MODULE_LICENSE("GPL v2"); 861