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/random.h> 24 #include <linux/regmap.h> 25 #include <linux/regulator/consumer.h> 26 #include <linux/pm_runtime.h> 27 28 #include <linux/iio/iio.h> 29 #include <linux/iio/sysfs.h> 30 #include <linux/iio/buffer.h> 31 #include <linux/iio/trigger.h> 32 #include <linux/iio/trigger_consumer.h> 33 #include <linux/iio/triggered_buffer.h> 34 35 /* 36 * 16-bit registers are little-endian. LSB is at the address defined below 37 * and MSB is at the next higher address. 38 */ 39 40 /* These registers are common for AK8974 and AMI30x */ 41 #define AK8974_SELFTEST 0x0C 42 #define AK8974_SELFTEST_IDLE 0x55 43 #define AK8974_SELFTEST_OK 0xAA 44 45 #define AK8974_INFO 0x0D 46 47 #define AK8974_WHOAMI 0x0F 48 #define AK8974_WHOAMI_VALUE_AMI306 0x46 49 #define AK8974_WHOAMI_VALUE_AMI305 0x47 50 #define AK8974_WHOAMI_VALUE_AK8974 0x48 51 52 #define AK8974_DATA_X 0x10 53 #define AK8974_DATA_Y 0x12 54 #define AK8974_DATA_Z 0x14 55 #define AK8974_INT_SRC 0x16 56 #define AK8974_STATUS 0x18 57 #define AK8974_INT_CLEAR 0x1A 58 #define AK8974_CTRL1 0x1B 59 #define AK8974_CTRL2 0x1C 60 #define AK8974_CTRL3 0x1D 61 #define AK8974_INT_CTRL 0x1E 62 #define AK8974_INT_THRES 0x26 /* Absolute any axis value threshold */ 63 #define AK8974_PRESET 0x30 64 65 /* AK8974-specific offsets */ 66 #define AK8974_OFFSET_X 0x20 67 #define AK8974_OFFSET_Y 0x22 68 #define AK8974_OFFSET_Z 0x24 69 /* AMI305-specific offsets */ 70 #define AMI305_OFFSET_X 0x6C 71 #define AMI305_OFFSET_Y 0x72 72 #define AMI305_OFFSET_Z 0x78 73 74 /* Different temperature registers */ 75 #define AK8974_TEMP 0x31 76 #define AMI305_TEMP 0x60 77 78 /* AMI306-specific control register */ 79 #define AMI306_CTRL4 0x5C 80 81 /* AMI306 factory calibration data */ 82 83 /* fine axis sensitivity */ 84 #define AMI306_FINEOUTPUT_X 0x90 85 #define AMI306_FINEOUTPUT_Y 0x92 86 #define AMI306_FINEOUTPUT_Z 0x94 87 88 /* axis sensitivity */ 89 #define AMI306_SENS_X 0x96 90 #define AMI306_SENS_Y 0x98 91 #define AMI306_SENS_Z 0x9A 92 93 /* axis cross-interference */ 94 #define AMI306_GAIN_PARA_XZ 0x9C 95 #define AMI306_GAIN_PARA_XY 0x9D 96 #define AMI306_GAIN_PARA_YZ 0x9E 97 #define AMI306_GAIN_PARA_YX 0x9F 98 #define AMI306_GAIN_PARA_ZY 0xA0 99 #define AMI306_GAIN_PARA_ZX 0xA1 100 101 /* offset at ZERO magnetic field */ 102 #define AMI306_OFFZERO_X 0xF8 103 #define AMI306_OFFZERO_Y 0xFA 104 #define AMI306_OFFZERO_Z 0xFC 105 106 107 #define AK8974_INT_X_HIGH BIT(7) /* Axis over +threshold */ 108 #define AK8974_INT_Y_HIGH BIT(6) 109 #define AK8974_INT_Z_HIGH BIT(5) 110 #define AK8974_INT_X_LOW BIT(4) /* Axis below -threshold */ 111 #define AK8974_INT_Y_LOW BIT(3) 112 #define AK8974_INT_Z_LOW BIT(2) 113 #define AK8974_INT_RANGE BIT(1) /* Range overflow (any axis) */ 114 115 #define AK8974_STATUS_DRDY BIT(6) /* Data ready */ 116 #define AK8974_STATUS_OVERRUN BIT(5) /* Data overrun */ 117 #define AK8974_STATUS_INT BIT(4) /* Interrupt occurred */ 118 119 #define AK8974_CTRL1_POWER BIT(7) /* 0 = standby; 1 = active */ 120 #define AK8974_CTRL1_RATE BIT(4) /* 0 = 10 Hz; 1 = 20 Hz */ 121 #define AK8974_CTRL1_FORCE_EN BIT(1) /* 0 = normal; 1 = force */ 122 #define AK8974_CTRL1_MODE2 BIT(0) /* 0 */ 123 124 #define AK8974_CTRL2_INT_EN BIT(4) /* 1 = enable interrupts */ 125 #define AK8974_CTRL2_DRDY_EN BIT(3) /* 1 = enable data ready signal */ 126 #define AK8974_CTRL2_DRDY_POL BIT(2) /* 1 = data ready active high */ 127 #define AK8974_CTRL2_RESDEF (AK8974_CTRL2_DRDY_POL) 128 129 #define AK8974_CTRL3_RESET BIT(7) /* Software reset */ 130 #define AK8974_CTRL3_FORCE BIT(6) /* Start forced measurement */ 131 #define AK8974_CTRL3_SELFTEST BIT(4) /* Set selftest register */ 132 #define AK8974_CTRL3_RESDEF 0x00 133 134 #define AK8974_INT_CTRL_XEN BIT(7) /* Enable interrupt for this axis */ 135 #define AK8974_INT_CTRL_YEN BIT(6) 136 #define AK8974_INT_CTRL_ZEN BIT(5) 137 #define AK8974_INT_CTRL_XYZEN (BIT(7)|BIT(6)|BIT(5)) 138 #define AK8974_INT_CTRL_POL BIT(3) /* 0 = active low; 1 = active high */ 139 #define AK8974_INT_CTRL_PULSE BIT(1) /* 0 = latched; 1 = pulse (50 usec) */ 140 #define AK8974_INT_CTRL_RESDEF (AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL) 141 142 /* The AMI305 has elaborate FW version and serial number registers */ 143 #define AMI305_VER 0xE8 144 #define AMI305_SN 0xEA 145 146 #define AK8974_MAX_RANGE 2048 147 148 #define AK8974_POWERON_DELAY 50 149 #define AK8974_ACTIVATE_DELAY 1 150 #define AK8974_SELFTEST_DELAY 1 151 /* 152 * Set the autosuspend to two orders of magnitude larger than the poweron 153 * delay to make sane reasonable power tradeoff savings (5 seconds in 154 * this case). 155 */ 156 #define AK8974_AUTOSUSPEND_DELAY 5000 157 158 #define AK8974_MEASTIME 3 159 160 #define AK8974_PWR_ON 1 161 #define AK8974_PWR_OFF 0 162 163 /** 164 * struct ak8974 - state container for the AK8974 driver 165 * @i2c: parent I2C client 166 * @orientation: mounting matrix, flipped axis etc 167 * @map: regmap to access the AK8974 registers over I2C 168 * @regs: the avdd and dvdd power regulators 169 * @name: the name of the part 170 * @variant: the whoami ID value (for selecting code paths) 171 * @lock: locks the magnetometer for exclusive use during a measurement 172 * @drdy_irq: uses the DRDY IRQ line 173 * @drdy_complete: completion for DRDY 174 * @drdy_active_low: the DRDY IRQ is active low 175 */ 176 struct ak8974 { 177 struct i2c_client *i2c; 178 struct iio_mount_matrix orientation; 179 struct regmap *map; 180 struct regulator_bulk_data regs[2]; 181 const char *name; 182 u8 variant; 183 struct mutex lock; 184 bool drdy_irq; 185 struct completion drdy_complete; 186 bool drdy_active_low; 187 }; 188 189 static const char ak8974_reg_avdd[] = "avdd"; 190 static const char ak8974_reg_dvdd[] = "dvdd"; 191 192 static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val) 193 { 194 int ret; 195 __le16 bulk; 196 197 ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2); 198 if (ret) 199 return ret; 200 *val = le16_to_cpu(bulk); 201 202 return 0; 203 } 204 205 static int ak8974_set_u16_val(struct ak8974 *ak8974, u8 reg, u16 val) 206 { 207 __le16 bulk = cpu_to_le16(val); 208 209 return regmap_bulk_write(ak8974->map, reg, &bulk, 2); 210 } 211 212 static int ak8974_set_power(struct ak8974 *ak8974, bool mode) 213 { 214 int ret; 215 u8 val; 216 217 val = mode ? AK8974_CTRL1_POWER : 0; 218 val |= AK8974_CTRL1_FORCE_EN; 219 ret = regmap_write(ak8974->map, AK8974_CTRL1, val); 220 if (ret < 0) 221 return ret; 222 223 if (mode) 224 msleep(AK8974_ACTIVATE_DELAY); 225 226 return 0; 227 } 228 229 static int ak8974_reset(struct ak8974 *ak8974) 230 { 231 int ret; 232 233 /* Power on to get register access. Sets CTRL1 reg to reset state */ 234 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 235 if (ret) 236 return ret; 237 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF); 238 if (ret) 239 return ret; 240 ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF); 241 if (ret) 242 return ret; 243 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, 244 AK8974_INT_CTRL_RESDEF); 245 if (ret) 246 return ret; 247 248 /* After reset, power off is default state */ 249 return ak8974_set_power(ak8974, AK8974_PWR_OFF); 250 } 251 252 static int ak8974_configure(struct ak8974 *ak8974) 253 { 254 int ret; 255 256 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN | 257 AK8974_CTRL2_INT_EN); 258 if (ret) 259 return ret; 260 ret = regmap_write(ak8974->map, AK8974_CTRL3, 0); 261 if (ret) 262 return ret; 263 if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI306) { 264 /* magic from datasheet: set high-speed measurement mode */ 265 ret = ak8974_set_u16_val(ak8974, AMI306_CTRL4, 0xA07E); 266 if (ret) 267 return ret; 268 } 269 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL); 270 if (ret) 271 return ret; 272 273 return regmap_write(ak8974->map, AK8974_PRESET, 0); 274 } 275 276 static int ak8974_trigmeas(struct ak8974 *ak8974) 277 { 278 unsigned int clear; 279 u8 mask; 280 u8 val; 281 int ret; 282 283 /* Clear any previous measurement overflow status */ 284 ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear); 285 if (ret) 286 return ret; 287 288 /* If we have a DRDY IRQ line, use it */ 289 if (ak8974->drdy_irq) { 290 mask = AK8974_CTRL2_INT_EN | 291 AK8974_CTRL2_DRDY_EN | 292 AK8974_CTRL2_DRDY_POL; 293 val = AK8974_CTRL2_DRDY_EN; 294 295 if (!ak8974->drdy_active_low) 296 val |= AK8974_CTRL2_DRDY_POL; 297 298 init_completion(&ak8974->drdy_complete); 299 ret = regmap_update_bits(ak8974->map, AK8974_CTRL2, 300 mask, val); 301 if (ret) 302 return ret; 303 } 304 305 /* Force a measurement */ 306 return regmap_update_bits(ak8974->map, 307 AK8974_CTRL3, 308 AK8974_CTRL3_FORCE, 309 AK8974_CTRL3_FORCE); 310 } 311 312 static int ak8974_await_drdy(struct ak8974 *ak8974) 313 { 314 int timeout = 2; 315 unsigned int val; 316 int ret; 317 318 if (ak8974->drdy_irq) { 319 ret = wait_for_completion_timeout(&ak8974->drdy_complete, 320 1 + msecs_to_jiffies(1000)); 321 if (!ret) { 322 dev_err(&ak8974->i2c->dev, 323 "timeout waiting for DRDY IRQ\n"); 324 return -ETIMEDOUT; 325 } 326 return 0; 327 } 328 329 /* Default delay-based poll loop */ 330 do { 331 msleep(AK8974_MEASTIME); 332 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 333 if (ret < 0) 334 return ret; 335 if (val & AK8974_STATUS_DRDY) 336 return 0; 337 } while (--timeout); 338 339 dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n"); 340 return -ETIMEDOUT; 341 } 342 343 static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result) 344 { 345 unsigned int src; 346 int ret; 347 348 ret = ak8974_await_drdy(ak8974); 349 if (ret) 350 return ret; 351 ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src); 352 if (ret < 0) 353 return ret; 354 355 /* Out of range overflow! Strong magnet close? */ 356 if (src & AK8974_INT_RANGE) { 357 dev_err(&ak8974->i2c->dev, 358 "range overflow in sensor\n"); 359 return -ERANGE; 360 } 361 362 ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6); 363 if (ret) 364 return ret; 365 366 return ret; 367 } 368 369 static irqreturn_t ak8974_drdy_irq(int irq, void *d) 370 { 371 struct ak8974 *ak8974 = d; 372 373 if (!ak8974->drdy_irq) 374 return IRQ_NONE; 375 376 /* TODO: timestamp here to get good measurement stamps */ 377 return IRQ_WAKE_THREAD; 378 } 379 380 static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d) 381 { 382 struct ak8974 *ak8974 = d; 383 unsigned int val; 384 int ret; 385 386 /* Check if this was a DRDY from us */ 387 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 388 if (ret < 0) { 389 dev_err(&ak8974->i2c->dev, "error reading DRDY status\n"); 390 return IRQ_HANDLED; 391 } 392 if (val & AK8974_STATUS_DRDY) { 393 /* Yes this was our IRQ */ 394 complete(&ak8974->drdy_complete); 395 return IRQ_HANDLED; 396 } 397 398 /* We may be on a shared IRQ, let the next client check */ 399 return IRQ_NONE; 400 } 401 402 static int ak8974_selftest(struct ak8974 *ak8974) 403 { 404 struct device *dev = &ak8974->i2c->dev; 405 unsigned int val; 406 int ret; 407 408 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 409 if (ret) 410 return ret; 411 if (val != AK8974_SELFTEST_IDLE) { 412 dev_err(dev, "selftest not idle before test\n"); 413 return -EIO; 414 } 415 416 /* Trigger self-test */ 417 ret = regmap_update_bits(ak8974->map, 418 AK8974_CTRL3, 419 AK8974_CTRL3_SELFTEST, 420 AK8974_CTRL3_SELFTEST); 421 if (ret) { 422 dev_err(dev, "could not write CTRL3\n"); 423 return ret; 424 } 425 426 msleep(AK8974_SELFTEST_DELAY); 427 428 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 429 if (ret) 430 return ret; 431 if (val != AK8974_SELFTEST_OK) { 432 dev_err(dev, "selftest result NOT OK (%02x)\n", val); 433 return -EIO; 434 } 435 436 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 437 if (ret) 438 return ret; 439 if (val != AK8974_SELFTEST_IDLE) { 440 dev_err(dev, "selftest not idle after test (%02x)\n", val); 441 return -EIO; 442 } 443 dev_dbg(dev, "passed self-test\n"); 444 445 return 0; 446 } 447 448 static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg, 449 __le16 *tab, size_t tab_size) 450 { 451 int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size); 452 if (ret) { 453 memset(tab, 0xFF, tab_size); 454 dev_warn(&ak8974->i2c->dev, 455 "can't read calibration data (regs %u..%zu): %d\n", 456 reg, reg + tab_size - 1, ret); 457 } else { 458 add_device_randomness(tab, tab_size); 459 } 460 } 461 462 static int ak8974_detect(struct ak8974 *ak8974) 463 { 464 unsigned int whoami; 465 const char *name; 466 int ret; 467 unsigned int fw; 468 u16 sn; 469 470 ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami); 471 if (ret) 472 return ret; 473 474 name = "ami305"; 475 476 switch (whoami) { 477 case AK8974_WHOAMI_VALUE_AMI306: 478 name = "ami306"; 479 /* fall-through */ 480 case AK8974_WHOAMI_VALUE_AMI305: 481 ret = regmap_read(ak8974->map, AMI305_VER, &fw); 482 if (ret) 483 return ret; 484 fw &= 0x7f; /* only bits 0 thru 6 valid */ 485 ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn); 486 if (ret) 487 return ret; 488 add_device_randomness(&sn, sizeof(sn)); 489 dev_info(&ak8974->i2c->dev, 490 "detected %s, FW ver %02x, S/N: %04x\n", 491 name, fw, sn); 492 break; 493 case AK8974_WHOAMI_VALUE_AK8974: 494 name = "ak8974"; 495 dev_info(&ak8974->i2c->dev, "detected AK8974\n"); 496 break; 497 default: 498 dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ", 499 whoami); 500 return -ENODEV; 501 } 502 503 ak8974->name = name; 504 ak8974->variant = whoami; 505 506 if (whoami == AK8974_WHOAMI_VALUE_AMI306) { 507 __le16 fab_data1[9], fab_data2[3]; 508 int i; 509 510 ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X, 511 fab_data1, sizeof(fab_data1)); 512 ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X, 513 fab_data2, sizeof(fab_data2)); 514 515 for (i = 0; i < 3; ++i) { 516 static const char axis[3] = "XYZ"; 517 static const char pgaxis[6] = "ZYZXYX"; 518 unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F; 519 unsigned fine = le16_to_cpu(fab_data1[i]); 520 unsigned sens = le16_to_cpu(fab_data1[i + 3]); 521 unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]); 522 unsigned pgain2 = pgain1 >> 8; 523 524 pgain1 &= 0xFF; 525 526 dev_info(&ak8974->i2c->dev, 527 "factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n", 528 axis[i], offz, sens, fine, pgaxis[i * 2], 529 pgain1, pgaxis[i * 2 + 1], pgain2); 530 } 531 } 532 533 return 0; 534 } 535 536 static int ak8974_read_raw(struct iio_dev *indio_dev, 537 struct iio_chan_spec const *chan, 538 int *val, int *val2, 539 long mask) 540 { 541 struct ak8974 *ak8974 = iio_priv(indio_dev); 542 __le16 hw_values[3]; 543 int ret = -EINVAL; 544 545 pm_runtime_get_sync(&ak8974->i2c->dev); 546 mutex_lock(&ak8974->lock); 547 548 switch (mask) { 549 case IIO_CHAN_INFO_RAW: 550 if (chan->address > 2) { 551 dev_err(&ak8974->i2c->dev, "faulty channel address\n"); 552 ret = -EIO; 553 goto out_unlock; 554 } 555 ret = ak8974_trigmeas(ak8974); 556 if (ret) 557 goto out_unlock; 558 ret = ak8974_getresult(ak8974, hw_values); 559 if (ret) 560 goto out_unlock; 561 562 /* 563 * We read all axes and discard all but one, for optimized 564 * reading, use the triggered buffer. 565 */ 566 *val = le16_to_cpu(hw_values[chan->address]); 567 568 ret = IIO_VAL_INT; 569 } 570 571 out_unlock: 572 mutex_unlock(&ak8974->lock); 573 pm_runtime_mark_last_busy(&ak8974->i2c->dev); 574 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 575 576 return ret; 577 } 578 579 static void ak8974_fill_buffer(struct iio_dev *indio_dev) 580 { 581 struct ak8974 *ak8974 = iio_priv(indio_dev); 582 int ret; 583 __le16 hw_values[8]; /* Three axes + 64bit padding */ 584 585 pm_runtime_get_sync(&ak8974->i2c->dev); 586 mutex_lock(&ak8974->lock); 587 588 ret = ak8974_trigmeas(ak8974); 589 if (ret) { 590 dev_err(&ak8974->i2c->dev, "error triggering measure\n"); 591 goto out_unlock; 592 } 593 ret = ak8974_getresult(ak8974, hw_values); 594 if (ret) { 595 dev_err(&ak8974->i2c->dev, "error getting measures\n"); 596 goto out_unlock; 597 } 598 599 iio_push_to_buffers_with_timestamp(indio_dev, hw_values, 600 iio_get_time_ns(indio_dev)); 601 602 out_unlock: 603 mutex_unlock(&ak8974->lock); 604 pm_runtime_mark_last_busy(&ak8974->i2c->dev); 605 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 606 } 607 608 static irqreturn_t ak8974_handle_trigger(int irq, void *p) 609 { 610 const struct iio_poll_func *pf = p; 611 struct iio_dev *indio_dev = pf->indio_dev; 612 613 ak8974_fill_buffer(indio_dev); 614 iio_trigger_notify_done(indio_dev->trig); 615 616 return IRQ_HANDLED; 617 } 618 619 static const struct iio_mount_matrix * 620 ak8974_get_mount_matrix(const struct iio_dev *indio_dev, 621 const struct iio_chan_spec *chan) 622 { 623 struct ak8974 *ak8974 = iio_priv(indio_dev); 624 625 return &ak8974->orientation; 626 } 627 628 static const struct iio_chan_spec_ext_info ak8974_ext_info[] = { 629 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix), 630 { }, 631 }; 632 633 #define AK8974_AXIS_CHANNEL(axis, index) \ 634 { \ 635 .type = IIO_MAGN, \ 636 .modified = 1, \ 637 .channel2 = IIO_MOD_##axis, \ 638 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 639 .ext_info = ak8974_ext_info, \ 640 .address = index, \ 641 .scan_index = index, \ 642 .scan_type = { \ 643 .sign = 's', \ 644 .realbits = 16, \ 645 .storagebits = 16, \ 646 .endianness = IIO_LE \ 647 }, \ 648 } 649 650 static const struct iio_chan_spec ak8974_channels[] = { 651 AK8974_AXIS_CHANNEL(X, 0), 652 AK8974_AXIS_CHANNEL(Y, 1), 653 AK8974_AXIS_CHANNEL(Z, 2), 654 IIO_CHAN_SOFT_TIMESTAMP(3), 655 }; 656 657 static const unsigned long ak8974_scan_masks[] = { 0x7, 0 }; 658 659 static const struct iio_info ak8974_info = { 660 .read_raw = &ak8974_read_raw, 661 .driver_module = THIS_MODULE, 662 }; 663 664 static bool ak8974_writeable_reg(struct device *dev, unsigned int reg) 665 { 666 struct i2c_client *i2c = to_i2c_client(dev); 667 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 668 struct ak8974 *ak8974 = iio_priv(indio_dev); 669 670 switch (reg) { 671 case AK8974_CTRL1: 672 case AK8974_CTRL2: 673 case AK8974_CTRL3: 674 case AK8974_INT_CTRL: 675 case AK8974_INT_THRES: 676 case AK8974_INT_THRES + 1: 677 case AK8974_PRESET: 678 case AK8974_PRESET + 1: 679 return true; 680 case AK8974_OFFSET_X: 681 case AK8974_OFFSET_X + 1: 682 case AK8974_OFFSET_Y: 683 case AK8974_OFFSET_Y + 1: 684 case AK8974_OFFSET_Z: 685 case AK8974_OFFSET_Z + 1: 686 if (ak8974->variant == AK8974_WHOAMI_VALUE_AK8974) 687 return true; 688 return false; 689 case AMI305_OFFSET_X: 690 case AMI305_OFFSET_X + 1: 691 case AMI305_OFFSET_Y: 692 case AMI305_OFFSET_Y + 1: 693 case AMI305_OFFSET_Z: 694 case AMI305_OFFSET_Z + 1: 695 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 || 696 ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; 697 case AMI306_CTRL4: 698 case AMI306_CTRL4 + 1: 699 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; 700 default: 701 return false; 702 } 703 } 704 705 static bool ak8974_precious_reg(struct device *dev, unsigned int reg) 706 { 707 return reg == AK8974_INT_CLEAR; 708 } 709 710 static const struct regmap_config ak8974_regmap_config = { 711 .reg_bits = 8, 712 .val_bits = 8, 713 .max_register = 0xff, 714 .writeable_reg = ak8974_writeable_reg, 715 .precious_reg = ak8974_precious_reg, 716 }; 717 718 static int ak8974_probe(struct i2c_client *i2c, 719 const struct i2c_device_id *id) 720 { 721 struct iio_dev *indio_dev; 722 struct ak8974 *ak8974; 723 unsigned long irq_trig; 724 int irq = i2c->irq; 725 int ret; 726 727 /* Register with IIO */ 728 indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974)); 729 if (indio_dev == NULL) 730 return -ENOMEM; 731 732 ak8974 = iio_priv(indio_dev); 733 i2c_set_clientdata(i2c, indio_dev); 734 ak8974->i2c = i2c; 735 mutex_init(&ak8974->lock); 736 737 ret = of_iio_read_mount_matrix(&i2c->dev, 738 "mount-matrix", 739 &ak8974->orientation); 740 if (ret) 741 return ret; 742 743 ak8974->regs[0].supply = ak8974_reg_avdd; 744 ak8974->regs[1].supply = ak8974_reg_dvdd; 745 746 ret = devm_regulator_bulk_get(&i2c->dev, 747 ARRAY_SIZE(ak8974->regs), 748 ak8974->regs); 749 if (ret < 0) { 750 dev_err(&i2c->dev, "cannot get regulators\n"); 751 return ret; 752 } 753 754 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 755 if (ret < 0) { 756 dev_err(&i2c->dev, "cannot enable regulators\n"); 757 return ret; 758 } 759 760 /* Take runtime PM online */ 761 pm_runtime_get_noresume(&i2c->dev); 762 pm_runtime_set_active(&i2c->dev); 763 pm_runtime_enable(&i2c->dev); 764 765 ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config); 766 if (IS_ERR(ak8974->map)) { 767 dev_err(&i2c->dev, "failed to allocate register map\n"); 768 return PTR_ERR(ak8974->map); 769 } 770 771 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 772 if (ret) { 773 dev_err(&i2c->dev, "could not power on\n"); 774 goto power_off; 775 } 776 777 ret = ak8974_detect(ak8974); 778 if (ret) { 779 dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n"); 780 goto power_off; 781 } 782 783 ret = ak8974_selftest(ak8974); 784 if (ret) 785 dev_err(&i2c->dev, "selftest failed (continuing anyway)\n"); 786 787 ret = ak8974_reset(ak8974); 788 if (ret) { 789 dev_err(&i2c->dev, "AK8974 reset failed\n"); 790 goto power_off; 791 } 792 793 pm_runtime_set_autosuspend_delay(&i2c->dev, 794 AK8974_AUTOSUSPEND_DELAY); 795 pm_runtime_use_autosuspend(&i2c->dev); 796 pm_runtime_put(&i2c->dev); 797 798 indio_dev->dev.parent = &i2c->dev; 799 indio_dev->channels = ak8974_channels; 800 indio_dev->num_channels = ARRAY_SIZE(ak8974_channels); 801 indio_dev->info = &ak8974_info; 802 indio_dev->available_scan_masks = ak8974_scan_masks; 803 indio_dev->modes = INDIO_DIRECT_MODE; 804 indio_dev->name = ak8974->name; 805 806 ret = iio_triggered_buffer_setup(indio_dev, NULL, 807 ak8974_handle_trigger, 808 NULL); 809 if (ret) { 810 dev_err(&i2c->dev, "triggered buffer setup failed\n"); 811 goto disable_pm; 812 } 813 814 /* If we have a valid DRDY IRQ, make use of it */ 815 if (irq > 0) { 816 irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq)); 817 if (irq_trig == IRQF_TRIGGER_RISING) { 818 dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n"); 819 } else if (irq_trig == IRQF_TRIGGER_FALLING) { 820 ak8974->drdy_active_low = true; 821 dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n"); 822 } else { 823 irq_trig = IRQF_TRIGGER_RISING; 824 } 825 irq_trig |= IRQF_ONESHOT; 826 irq_trig |= IRQF_SHARED; 827 828 ret = devm_request_threaded_irq(&i2c->dev, 829 irq, 830 ak8974_drdy_irq, 831 ak8974_drdy_irq_thread, 832 irq_trig, 833 ak8974->name, 834 ak8974); 835 if (ret) { 836 dev_err(&i2c->dev, "unable to request DRDY IRQ " 837 "- proceeding without IRQ\n"); 838 goto no_irq; 839 } 840 ak8974->drdy_irq = true; 841 } 842 843 no_irq: 844 ret = iio_device_register(indio_dev); 845 if (ret) { 846 dev_err(&i2c->dev, "device register failed\n"); 847 goto cleanup_buffer; 848 } 849 850 return 0; 851 852 cleanup_buffer: 853 iio_triggered_buffer_cleanup(indio_dev); 854 disable_pm: 855 pm_runtime_put_noidle(&i2c->dev); 856 pm_runtime_disable(&i2c->dev); 857 ak8974_set_power(ak8974, AK8974_PWR_OFF); 858 power_off: 859 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 860 861 return ret; 862 } 863 864 static int ak8974_remove(struct i2c_client *i2c) 865 { 866 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 867 struct ak8974 *ak8974 = iio_priv(indio_dev); 868 869 iio_device_unregister(indio_dev); 870 iio_triggered_buffer_cleanup(indio_dev); 871 pm_runtime_get_sync(&i2c->dev); 872 pm_runtime_put_noidle(&i2c->dev); 873 pm_runtime_disable(&i2c->dev); 874 ak8974_set_power(ak8974, AK8974_PWR_OFF); 875 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 876 877 return 0; 878 } 879 880 static int __maybe_unused ak8974_runtime_suspend(struct device *dev) 881 { 882 struct ak8974 *ak8974 = 883 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 884 885 ak8974_set_power(ak8974, AK8974_PWR_OFF); 886 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 887 888 return 0; 889 } 890 891 static int __maybe_unused ak8974_runtime_resume(struct device *dev) 892 { 893 struct ak8974 *ak8974 = 894 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 895 int ret; 896 897 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 898 if (ret) 899 return ret; 900 msleep(AK8974_POWERON_DELAY); 901 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 902 if (ret) 903 goto out_regulator_disable; 904 905 ret = ak8974_configure(ak8974); 906 if (ret) 907 goto out_disable_power; 908 909 return 0; 910 911 out_disable_power: 912 ak8974_set_power(ak8974, AK8974_PWR_OFF); 913 out_regulator_disable: 914 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 915 916 return ret; 917 } 918 919 static const struct dev_pm_ops ak8974_dev_pm_ops = { 920 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, 921 pm_runtime_force_resume) 922 SET_RUNTIME_PM_OPS(ak8974_runtime_suspend, 923 ak8974_runtime_resume, NULL) 924 }; 925 926 static const struct i2c_device_id ak8974_id[] = { 927 {"ami305", 0 }, 928 {"ami306", 0 }, 929 {"ak8974", 0 }, 930 {} 931 }; 932 MODULE_DEVICE_TABLE(i2c, ak8974_id); 933 934 static const struct of_device_id ak8974_of_match[] = { 935 { .compatible = "asahi-kasei,ak8974", }, 936 {} 937 }; 938 MODULE_DEVICE_TABLE(of, ak8974_of_match); 939 940 static struct i2c_driver ak8974_driver = { 941 .driver = { 942 .name = "ak8974", 943 .pm = &ak8974_dev_pm_ops, 944 .of_match_table = of_match_ptr(ak8974_of_match), 945 }, 946 .probe = ak8974_probe, 947 .remove = ak8974_remove, 948 .id_table = ak8974_id, 949 }; 950 module_i2c_driver(ak8974_driver); 951 952 MODULE_DESCRIPTION("AK8974 and AMI30x 3-axis magnetometer driver"); 953 MODULE_AUTHOR("Samu Onkalo"); 954 MODULE_AUTHOR("Linus Walleij"); 955 MODULE_LICENSE("GPL v2"); 956