1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * Driver for the Asahi Kasei EMD Corporation AK8974 4 * and Aichi Steel AMI305 magnetometer chips. 5 * Based on a patch from Samu Onkalo and the AK8975 IIO driver. 6 * 7 * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). 8 * Copyright (c) 2010 NVIDIA Corporation. 9 * Copyright (C) 2016 Linaro Ltd. 10 * 11 * Author: Samu Onkalo <samu.p.onkalo@nokia.com> 12 * Author: Linus Walleij <linus.walleij@linaro.org> 13 */ 14#include <linux/module.h> 15#include <linux/mod_devicetable.h> 16#include <linux/kernel.h> 17#include <linux/i2c.h> 18#include <linux/interrupt.h> 19#include <linux/irq.h> /* For irq_get_irq_data() */ 20#include <linux/completion.h> 21#include <linux/err.h> 22#include <linux/mutex.h> 23#include <linux/delay.h> 24#include <linux/bitops.h> 25#include <linux/random.h> 26#include <linux/regmap.h> 27#include <linux/regulator/consumer.h> 28#include <linux/pm_runtime.h> 29 30#include <linux/iio/iio.h> 31#include <linux/iio/sysfs.h> 32#include <linux/iio/buffer.h> 33#include <linux/iio/trigger.h> 34#include <linux/iio/trigger_consumer.h> 35#include <linux/iio/triggered_buffer.h> 36 37/* 38 * 16-bit registers are little-endian. LSB is at the address defined below 39 * and MSB is at the next higher address. 40 */ 41 42/* These registers are common for AK8974 and AMI30x */ 43#define AK8974_SELFTEST 0x0C 44#define AK8974_SELFTEST_IDLE 0x55 45#define AK8974_SELFTEST_OK 0xAA 46 47#define AK8974_INFO 0x0D 48 49#define AK8974_WHOAMI 0x0F 50#define AK8974_WHOAMI_VALUE_AMI306 0x46 51#define AK8974_WHOAMI_VALUE_AMI305 0x47 52#define AK8974_WHOAMI_VALUE_AK8974 0x48 53#define AK8974_WHOAMI_VALUE_HSCDTD008A 0x49 54 55#define AK8974_DATA_X 0x10 56#define AK8974_DATA_Y 0x12 57#define AK8974_DATA_Z 0x14 58#define AK8974_INT_SRC 0x16 59#define AK8974_STATUS 0x18 60#define AK8974_INT_CLEAR 0x1A 61#define AK8974_CTRL1 0x1B 62#define AK8974_CTRL2 0x1C 63#define AK8974_CTRL3 0x1D 64#define AK8974_INT_CTRL 0x1E 65#define AK8974_INT_THRES 0x26 /* Absolute any axis value threshold */ 66#define AK8974_PRESET 0x30 67 68/* AK8974-specific offsets */ 69#define AK8974_OFFSET_X 0x20 70#define AK8974_OFFSET_Y 0x22 71#define AK8974_OFFSET_Z 0x24 72/* AMI305-specific offsets */ 73#define AMI305_OFFSET_X 0x6C 74#define AMI305_OFFSET_Y 0x72 75#define AMI305_OFFSET_Z 0x78 76 77/* Different temperature registers */ 78#define AK8974_TEMP 0x31 79#define AMI305_TEMP 0x60 80 81/* AMI306-specific control register */ 82#define AMI306_CTRL4 0x5C 83 84/* AMI306 factory calibration data */ 85 86/* fine axis sensitivity */ 87#define AMI306_FINEOUTPUT_X 0x90 88#define AMI306_FINEOUTPUT_Y 0x92 89#define AMI306_FINEOUTPUT_Z 0x94 90 91/* axis sensitivity */ 92#define AMI306_SENS_X 0x96 93#define AMI306_SENS_Y 0x98 94#define AMI306_SENS_Z 0x9A 95 96/* axis cross-interference */ 97#define AMI306_GAIN_PARA_XZ 0x9C 98#define AMI306_GAIN_PARA_XY 0x9D 99#define AMI306_GAIN_PARA_YZ 0x9E 100#define AMI306_GAIN_PARA_YX 0x9F 101#define AMI306_GAIN_PARA_ZY 0xA0 102#define AMI306_GAIN_PARA_ZX 0xA1 103 104/* offset at ZERO magnetic field */ 105#define AMI306_OFFZERO_X 0xF8 106#define AMI306_OFFZERO_Y 0xFA 107#define AMI306_OFFZERO_Z 0xFC 108 109 110#define AK8974_INT_X_HIGH BIT(7) /* Axis over +threshold */ 111#define AK8974_INT_Y_HIGH BIT(6) 112#define AK8974_INT_Z_HIGH BIT(5) 113#define AK8974_INT_X_LOW BIT(4) /* Axis below -threshold */ 114#define AK8974_INT_Y_LOW BIT(3) 115#define AK8974_INT_Z_LOW BIT(2) 116#define AK8974_INT_RANGE BIT(1) /* Range overflow (any axis) */ 117 118#define AK8974_STATUS_DRDY BIT(6) /* Data ready */ 119#define AK8974_STATUS_OVERRUN BIT(5) /* Data overrun */ 120#define AK8974_STATUS_INT BIT(4) /* Interrupt occurred */ 121 122#define AK8974_CTRL1_POWER BIT(7) /* 0 = standby; 1 = active */ 123#define AK8974_CTRL1_RATE BIT(4) /* 0 = 10 Hz; 1 = 20 Hz */ 124#define AK8974_CTRL1_FORCE_EN BIT(1) /* 0 = normal; 1 = force */ 125#define AK8974_CTRL1_MODE2 BIT(0) /* 0 */ 126 127#define AK8974_CTRL2_INT_EN BIT(4) /* 1 = enable interrupts */ 128#define AK8974_CTRL2_DRDY_EN BIT(3) /* 1 = enable data ready signal */ 129#define AK8974_CTRL2_DRDY_POL BIT(2) /* 1 = data ready active high */ 130#define AK8974_CTRL2_RESDEF (AK8974_CTRL2_DRDY_POL) 131 132#define AK8974_CTRL3_RESET BIT(7) /* Software reset */ 133#define AK8974_CTRL3_FORCE BIT(6) /* Start forced measurement */ 134#define AK8974_CTRL3_SELFTEST BIT(4) /* Set selftest register */ 135#define AK8974_CTRL3_RESDEF 0x00 136 137#define AK8974_INT_CTRL_XEN BIT(7) /* Enable interrupt for this axis */ 138#define AK8974_INT_CTRL_YEN BIT(6) 139#define AK8974_INT_CTRL_ZEN BIT(5) 140#define AK8974_INT_CTRL_XYZEN (BIT(7)|BIT(6)|BIT(5)) 141#define AK8974_INT_CTRL_POL BIT(3) /* 0 = active low; 1 = active high */ 142#define AK8974_INT_CTRL_PULSE BIT(1) /* 0 = latched; 1 = pulse (50 usec) */ 143#define AK8974_INT_CTRL_RESDEF (AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL) 144 145/* HSCDTD008A-specific control register */ 146#define HSCDTD008A_CTRL4 0x1E 147#define HSCDTD008A_CTRL4_MMD BIT(7) /* must be set to 1 */ 148#define HSCDTD008A_CTRL4_RANGE BIT(4) /* 0 = 14-bit output; 1 = 15-bit output */ 149#define HSCDTD008A_CTRL4_RESDEF (HSCDTD008A_CTRL4_MMD | HSCDTD008A_CTRL4_RANGE) 150 151/* The AMI305 has elaborate FW version and serial number registers */ 152#define AMI305_VER 0xE8 153#define AMI305_SN 0xEA 154 155#define AK8974_MAX_RANGE 2048 156 157#define AK8974_POWERON_DELAY 50 158#define AK8974_ACTIVATE_DELAY 1 159#define AK8974_SELFTEST_DELAY 1 160/* 161 * Set the autosuspend to two orders of magnitude larger than the poweron 162 * delay to make sane reasonable power tradeoff savings (5 seconds in 163 * this case). 164 */ 165#define AK8974_AUTOSUSPEND_DELAY 5000 166 167#define AK8974_MEASTIME 3 168 169#define AK8974_PWR_ON 1 170#define AK8974_PWR_OFF 0 171 172/** 173 * struct ak8974 - state container for the AK8974 driver 174 * @i2c: parent I2C client 175 * @orientation: mounting matrix, flipped axis etc 176 * @map: regmap to access the AK8974 registers over I2C 177 * @regs: the avdd and dvdd power regulators 178 * @name: the name of the part 179 * @variant: the whoami ID value (for selecting code paths) 180 * @lock: locks the magnetometer for exclusive use during a measurement 181 * @drdy_irq: uses the DRDY IRQ line 182 * @drdy_complete: completion for DRDY 183 * @drdy_active_low: the DRDY IRQ is active low 184 * @scan: timestamps 185 */ 186struct ak8974 { 187 struct i2c_client *i2c; 188 struct iio_mount_matrix orientation; 189 struct regmap *map; 190 struct regulator_bulk_data regs[2]; 191 const char *name; 192 u8 variant; 193 struct mutex lock; 194 bool drdy_irq; 195 struct completion drdy_complete; 196 bool drdy_active_low; 197 /* Ensure timestamp is naturally aligned */ 198 struct { 199 __le16 channels[3]; 200 s64 ts __aligned(8); 201 } scan; 202}; 203 204static const char ak8974_reg_avdd[] = "avdd"; 205static const char ak8974_reg_dvdd[] = "dvdd"; 206 207static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val) 208{ 209 int ret; 210 __le16 bulk; 211 212 ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2); 213 if (ret) 214 return ret; 215 *val = le16_to_cpu(bulk); 216 217 return 0; 218} 219 220static int ak8974_set_u16_val(struct ak8974 *ak8974, u8 reg, u16 val) 221{ 222 __le16 bulk = cpu_to_le16(val); 223 224 return regmap_bulk_write(ak8974->map, reg, &bulk, 2); 225} 226 227static int ak8974_set_power(struct ak8974 *ak8974, bool mode) 228{ 229 int ret; 230 u8 val; 231 232 val = mode ? AK8974_CTRL1_POWER : 0; 233 val |= AK8974_CTRL1_FORCE_EN; 234 ret = regmap_write(ak8974->map, AK8974_CTRL1, val); 235 if (ret < 0) 236 return ret; 237 238 if (mode) 239 msleep(AK8974_ACTIVATE_DELAY); 240 241 return 0; 242} 243 244static int ak8974_reset(struct ak8974 *ak8974) 245{ 246 int ret; 247 248 /* Power on to get register access. Sets CTRL1 reg to reset state */ 249 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 250 if (ret) 251 return ret; 252 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF); 253 if (ret) 254 return ret; 255 ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF); 256 if (ret) 257 return ret; 258 if (ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A) { 259 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, 260 AK8974_INT_CTRL_RESDEF); 261 if (ret) 262 return ret; 263 } else { 264 ret = regmap_write(ak8974->map, HSCDTD008A_CTRL4, 265 HSCDTD008A_CTRL4_RESDEF); 266 if (ret) 267 return ret; 268 } 269 270 /* After reset, power off is default state */ 271 return ak8974_set_power(ak8974, AK8974_PWR_OFF); 272} 273 274static int ak8974_configure(struct ak8974 *ak8974) 275{ 276 int ret; 277 278 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN | 279 AK8974_CTRL2_INT_EN); 280 if (ret) 281 return ret; 282 ret = regmap_write(ak8974->map, AK8974_CTRL3, 0); 283 if (ret) 284 return ret; 285 if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI306) { 286 /* magic from datasheet: set high-speed measurement mode */ 287 ret = ak8974_set_u16_val(ak8974, AMI306_CTRL4, 0xA07E); 288 if (ret) 289 return ret; 290 } 291 if (ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A) 292 return 0; 293 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL); 294 if (ret) 295 return ret; 296 297 return regmap_write(ak8974->map, AK8974_PRESET, 0); 298} 299 300static int ak8974_trigmeas(struct ak8974 *ak8974) 301{ 302 unsigned int clear; 303 u8 mask; 304 u8 val; 305 int ret; 306 307 /* Clear any previous measurement overflow status */ 308 ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear); 309 if (ret) 310 return ret; 311 312 /* If we have a DRDY IRQ line, use it */ 313 if (ak8974->drdy_irq) { 314 mask = AK8974_CTRL2_INT_EN | 315 AK8974_CTRL2_DRDY_EN | 316 AK8974_CTRL2_DRDY_POL; 317 val = AK8974_CTRL2_DRDY_EN; 318 319 if (!ak8974->drdy_active_low) 320 val |= AK8974_CTRL2_DRDY_POL; 321 322 init_completion(&ak8974->drdy_complete); 323 ret = regmap_update_bits(ak8974->map, AK8974_CTRL2, 324 mask, val); 325 if (ret) 326 return ret; 327 } 328 329 /* Force a measurement */ 330 return regmap_update_bits(ak8974->map, 331 AK8974_CTRL3, 332 AK8974_CTRL3_FORCE, 333 AK8974_CTRL3_FORCE); 334} 335 336static int ak8974_await_drdy(struct ak8974 *ak8974) 337{ 338 int timeout = 2; 339 unsigned int val; 340 int ret; 341 342 if (ak8974->drdy_irq) { 343 ret = wait_for_completion_timeout(&ak8974->drdy_complete, 344 1 + msecs_to_jiffies(1000)); 345 if (!ret) { 346 dev_err(&ak8974->i2c->dev, 347 "timeout waiting for DRDY IRQ\n"); 348 return -ETIMEDOUT; 349 } 350 return 0; 351 } 352 353 /* Default delay-based poll loop */ 354 do { 355 msleep(AK8974_MEASTIME); 356 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 357 if (ret < 0) 358 return ret; 359 if (val & AK8974_STATUS_DRDY) 360 return 0; 361 } while (--timeout); 362 363 dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n"); 364 return -ETIMEDOUT; 365} 366 367static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result) 368{ 369 unsigned int src; 370 int ret; 371 372 ret = ak8974_await_drdy(ak8974); 373 if (ret) 374 return ret; 375 ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src); 376 if (ret < 0) 377 return ret; 378 379 /* Out of range overflow! Strong magnet close? */ 380 if (src & AK8974_INT_RANGE) { 381 dev_err(&ak8974->i2c->dev, 382 "range overflow in sensor\n"); 383 return -ERANGE; 384 } 385 386 ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6); 387 if (ret) 388 return ret; 389 390 return ret; 391} 392 393static irqreturn_t ak8974_drdy_irq(int irq, void *d) 394{ 395 struct ak8974 *ak8974 = d; 396 397 if (!ak8974->drdy_irq) 398 return IRQ_NONE; 399 400 /* TODO: timestamp here to get good measurement stamps */ 401 return IRQ_WAKE_THREAD; 402} 403 404static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d) 405{ 406 struct ak8974 *ak8974 = d; 407 unsigned int val; 408 int ret; 409 410 /* Check if this was a DRDY from us */ 411 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 412 if (ret < 0) { 413 dev_err(&ak8974->i2c->dev, "error reading DRDY status\n"); 414 return IRQ_HANDLED; 415 } 416 if (val & AK8974_STATUS_DRDY) { 417 /* Yes this was our IRQ */ 418 complete(&ak8974->drdy_complete); 419 return IRQ_HANDLED; 420 } 421 422 /* We may be on a shared IRQ, let the next client check */ 423 return IRQ_NONE; 424} 425 426static int ak8974_selftest(struct ak8974 *ak8974) 427{ 428 struct device *dev = &ak8974->i2c->dev; 429 unsigned int val; 430 int ret; 431 432 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 433 if (ret) 434 return ret; 435 if (val != AK8974_SELFTEST_IDLE) { 436 dev_err(dev, "selftest not idle before test\n"); 437 return -EIO; 438 } 439 440 /* Trigger self-test */ 441 ret = regmap_update_bits(ak8974->map, 442 AK8974_CTRL3, 443 AK8974_CTRL3_SELFTEST, 444 AK8974_CTRL3_SELFTEST); 445 if (ret) { 446 dev_err(dev, "could not write CTRL3\n"); 447 return ret; 448 } 449 450 msleep(AK8974_SELFTEST_DELAY); 451 452 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 453 if (ret) 454 return ret; 455 if (val != AK8974_SELFTEST_OK) { 456 dev_err(dev, "selftest result NOT OK (%02x)\n", val); 457 return -EIO; 458 } 459 460 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 461 if (ret) 462 return ret; 463 if (val != AK8974_SELFTEST_IDLE) { 464 dev_err(dev, "selftest not idle after test (%02x)\n", val); 465 return -EIO; 466 } 467 dev_dbg(dev, "passed self-test\n"); 468 469 return 0; 470} 471 472static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg, 473 __le16 *tab, size_t tab_size) 474{ 475 int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size); 476 if (ret) { 477 memset(tab, 0xFF, tab_size); 478 dev_warn(&ak8974->i2c->dev, 479 "can't read calibration data (regs %u..%zu): %d\n", 480 reg, reg + tab_size - 1, ret); 481 } else { 482 add_device_randomness(tab, tab_size); 483 } 484} 485 486static int ak8974_detect(struct ak8974 *ak8974) 487{ 488 unsigned int whoami; 489 const char *name; 490 int ret; 491 unsigned int fw; 492 u16 sn; 493 494 ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami); 495 if (ret) 496 return ret; 497 498 name = "ami305"; 499 500 switch (whoami) { 501 case AK8974_WHOAMI_VALUE_AMI306: 502 name = "ami306"; 503 fallthrough; 504 case AK8974_WHOAMI_VALUE_AMI305: 505 ret = regmap_read(ak8974->map, AMI305_VER, &fw); 506 if (ret) 507 return ret; 508 fw &= 0x7f; /* only bits 0 thru 6 valid */ 509 ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn); 510 if (ret) 511 return ret; 512 add_device_randomness(&sn, sizeof(sn)); 513 dev_info(&ak8974->i2c->dev, 514 "detected %s, FW ver %02x, S/N: %04x\n", 515 name, fw, sn); 516 break; 517 case AK8974_WHOAMI_VALUE_AK8974: 518 name = "ak8974"; 519 dev_info(&ak8974->i2c->dev, "detected AK8974\n"); 520 break; 521 case AK8974_WHOAMI_VALUE_HSCDTD008A: 522 name = "hscdtd008a"; 523 dev_info(&ak8974->i2c->dev, "detected hscdtd008a\n"); 524 break; 525 default: 526 dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ", 527 whoami); 528 return -ENODEV; 529 } 530 531 ak8974->name = name; 532 ak8974->variant = whoami; 533 534 if (whoami == AK8974_WHOAMI_VALUE_AMI306) { 535 __le16 fab_data1[9], fab_data2[3]; 536 int i; 537 538 ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X, 539 fab_data1, sizeof(fab_data1)); 540 ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X, 541 fab_data2, sizeof(fab_data2)); 542 543 for (i = 0; i < 3; ++i) { 544 static const char axis[3] = "XYZ"; 545 static const char pgaxis[6] = "ZYZXYX"; 546 unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F; 547 unsigned fine = le16_to_cpu(fab_data1[i]); 548 unsigned sens = le16_to_cpu(fab_data1[i + 3]); 549 unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]); 550 unsigned pgain2 = pgain1 >> 8; 551 552 pgain1 &= 0xFF; 553 554 dev_info(&ak8974->i2c->dev, 555 "factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n", 556 axis[i], offz, sens, fine, pgaxis[i * 2], 557 pgain1, pgaxis[i * 2 + 1], pgain2); 558 } 559 } 560 561 return 0; 562} 563 564static int ak8974_measure_channel(struct ak8974 *ak8974, unsigned long address, 565 int *val) 566{ 567 __le16 hw_values[3]; 568 int ret; 569 570 pm_runtime_get_sync(&ak8974->i2c->dev); 571 mutex_lock(&ak8974->lock); 572 573 /* 574 * We read all axes and discard all but one, for optimized 575 * reading, use the triggered buffer. 576 */ 577 ret = ak8974_trigmeas(ak8974); 578 if (ret) 579 goto out_unlock; 580 ret = ak8974_getresult(ak8974, hw_values); 581 if (ret) 582 goto out_unlock; 583 /* 584 * This explicit cast to (s16) is necessary as the measurement 585 * is done in 2's complement with positive and negative values. 586 * The follwing assignment to *val will then convert the signed 587 * s16 value to a signed int value. 588 */ 589 *val = (s16)le16_to_cpu(hw_values[address]); 590out_unlock: 591 mutex_unlock(&ak8974->lock); 592 pm_runtime_mark_last_busy(&ak8974->i2c->dev); 593 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 594 595 return ret; 596} 597 598static int ak8974_read_raw(struct iio_dev *indio_dev, 599 struct iio_chan_spec const *chan, 600 int *val, int *val2, 601 long mask) 602{ 603 struct ak8974 *ak8974 = iio_priv(indio_dev); 604 int ret; 605 606 switch (mask) { 607 case IIO_CHAN_INFO_RAW: 608 if (chan->address > 2) { 609 dev_err(&ak8974->i2c->dev, "faulty channel address\n"); 610 return -EIO; 611 } 612 ret = ak8974_measure_channel(ak8974, chan->address, val); 613 if (ret) 614 return ret; 615 return IIO_VAL_INT; 616 case IIO_CHAN_INFO_SCALE: 617 switch (ak8974->variant) { 618 case AK8974_WHOAMI_VALUE_AMI306: 619 case AK8974_WHOAMI_VALUE_AMI305: 620 /* 621 * The datasheet for AMI305 and AMI306, page 6 622 * specifies the range of the sensor to be 623 * +/- 12 Gauss. 624 */ 625 *val = 12; 626 /* 627 * 12 bits are used, +/- 2^11 628 * [ -2048 .. 2047 ] (manual page 20) 629 * [ 0xf800 .. 0x07ff ] 630 */ 631 *val2 = 11; 632 return IIO_VAL_FRACTIONAL_LOG2; 633 case AK8974_WHOAMI_VALUE_HSCDTD008A: 634 /* 635 * The datasheet for HSCDTF008A, page 3 specifies the 636 * range of the sensor as +/- 2.4 mT per axis, which 637 * corresponds to +/- 2400 uT = +/- 24 Gauss. 638 */ 639 *val = 24; 640 /* 641 * 15 bits are used (set up in CTRL4), +/- 2^14 642 * [ -16384 .. 16383 ] (manual page 24) 643 * [ 0xc000 .. 0x3fff ] 644 */ 645 *val2 = 14; 646 return IIO_VAL_FRACTIONAL_LOG2; 647 default: 648 /* GUESSING +/- 12 Gauss */ 649 *val = 12; 650 /* GUESSING 12 bits ADC +/- 2^11 */ 651 *val2 = 11; 652 return IIO_VAL_FRACTIONAL_LOG2; 653 } 654 break; 655 default: 656 /* Unknown request */ 657 break; 658 } 659 660 return -EINVAL; 661} 662 663static void ak8974_fill_buffer(struct iio_dev *indio_dev) 664{ 665 struct ak8974 *ak8974 = iio_priv(indio_dev); 666 int ret; 667 668 pm_runtime_get_sync(&ak8974->i2c->dev); 669 mutex_lock(&ak8974->lock); 670 671 ret = ak8974_trigmeas(ak8974); 672 if (ret) { 673 dev_err(&ak8974->i2c->dev, "error triggering measure\n"); 674 goto out_unlock; 675 } 676 ret = ak8974_getresult(ak8974, ak8974->scan.channels); 677 if (ret) { 678 dev_err(&ak8974->i2c->dev, "error getting measures\n"); 679 goto out_unlock; 680 } 681 682 iio_push_to_buffers_with_timestamp(indio_dev, &ak8974->scan, 683 iio_get_time_ns(indio_dev)); 684 685 out_unlock: 686 mutex_unlock(&ak8974->lock); 687 pm_runtime_mark_last_busy(&ak8974->i2c->dev); 688 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 689} 690 691static irqreturn_t ak8974_handle_trigger(int irq, void *p) 692{ 693 const struct iio_poll_func *pf = p; 694 struct iio_dev *indio_dev = pf->indio_dev; 695 696 ak8974_fill_buffer(indio_dev); 697 iio_trigger_notify_done(indio_dev->trig); 698 699 return IRQ_HANDLED; 700} 701 702static const struct iio_mount_matrix * 703ak8974_get_mount_matrix(const struct iio_dev *indio_dev, 704 const struct iio_chan_spec *chan) 705{ 706 struct ak8974 *ak8974 = iio_priv(indio_dev); 707 708 return &ak8974->orientation; 709} 710 711static const struct iio_chan_spec_ext_info ak8974_ext_info[] = { 712 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix), 713 { }, 714}; 715 716#define AK8974_AXIS_CHANNEL(axis, index, bits) \ 717 { \ 718 .type = IIO_MAGN, \ 719 .modified = 1, \ 720 .channel2 = IIO_MOD_##axis, \ 721 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 722 BIT(IIO_CHAN_INFO_SCALE), \ 723 .ext_info = ak8974_ext_info, \ 724 .address = index, \ 725 .scan_index = index, \ 726 .scan_type = { \ 727 .sign = 's', \ 728 .realbits = bits, \ 729 .storagebits = 16, \ 730 .endianness = IIO_LE \ 731 }, \ 732 } 733 734/* 735 * We have no datasheet for the AK8974 but we guess that its 736 * ADC is 12 bits. The AMI305 and AMI306 certainly has 12bit 737 * ADC. 738 */ 739static const struct iio_chan_spec ak8974_12_bits_channels[] = { 740 AK8974_AXIS_CHANNEL(X, 0, 12), 741 AK8974_AXIS_CHANNEL(Y, 1, 12), 742 AK8974_AXIS_CHANNEL(Z, 2, 12), 743 IIO_CHAN_SOFT_TIMESTAMP(3), 744}; 745 746/* 747 * The HSCDTD008A has 15 bits resolution the way we set it up 748 * in CTRL4. 749 */ 750static const struct iio_chan_spec ak8974_15_bits_channels[] = { 751 AK8974_AXIS_CHANNEL(X, 0, 15), 752 AK8974_AXIS_CHANNEL(Y, 1, 15), 753 AK8974_AXIS_CHANNEL(Z, 2, 15), 754 IIO_CHAN_SOFT_TIMESTAMP(3), 755}; 756 757static const unsigned long ak8974_scan_masks[] = { 0x7, 0 }; 758 759static const struct iio_info ak8974_info = { 760 .read_raw = &ak8974_read_raw, 761}; 762 763static bool ak8974_writeable_reg(struct device *dev, unsigned int reg) 764{ 765 struct i2c_client *i2c = to_i2c_client(dev); 766 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 767 struct ak8974 *ak8974 = iio_priv(indio_dev); 768 769 switch (reg) { 770 case AK8974_CTRL1: 771 case AK8974_CTRL2: 772 case AK8974_CTRL3: 773 case AK8974_INT_CTRL: 774 case AK8974_INT_THRES: 775 case AK8974_INT_THRES + 1: 776 return true; 777 case AK8974_PRESET: 778 case AK8974_PRESET + 1: 779 return ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A; 780 case AK8974_OFFSET_X: 781 case AK8974_OFFSET_X + 1: 782 case AK8974_OFFSET_Y: 783 case AK8974_OFFSET_Y + 1: 784 case AK8974_OFFSET_Z: 785 case AK8974_OFFSET_Z + 1: 786 return ak8974->variant == AK8974_WHOAMI_VALUE_AK8974 || 787 ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A; 788 case AMI305_OFFSET_X: 789 case AMI305_OFFSET_X + 1: 790 case AMI305_OFFSET_Y: 791 case AMI305_OFFSET_Y + 1: 792 case AMI305_OFFSET_Z: 793 case AMI305_OFFSET_Z + 1: 794 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 || 795 ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; 796 case AMI306_CTRL4: 797 case AMI306_CTRL4 + 1: 798 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; 799 default: 800 return false; 801 } 802} 803 804static bool ak8974_precious_reg(struct device *dev, unsigned int reg) 805{ 806 return reg == AK8974_INT_CLEAR; 807} 808 809static const struct regmap_config ak8974_regmap_config = { 810 .reg_bits = 8, 811 .val_bits = 8, 812 .max_register = 0xff, 813 .writeable_reg = ak8974_writeable_reg, 814 .precious_reg = ak8974_precious_reg, 815}; 816 817static int ak8974_probe(struct i2c_client *i2c) 818{ 819 struct iio_dev *indio_dev; 820 struct ak8974 *ak8974; 821 unsigned long irq_trig; 822 int irq = i2c->irq; 823 int ret; 824 825 /* Register with IIO */ 826 indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974)); 827 if (indio_dev == NULL) 828 return -ENOMEM; 829 830 ak8974 = iio_priv(indio_dev); 831 i2c_set_clientdata(i2c, indio_dev); 832 ak8974->i2c = i2c; 833 mutex_init(&ak8974->lock); 834 835 ret = iio_read_mount_matrix(&i2c->dev, &ak8974->orientation); 836 if (ret) 837 return ret; 838 839 ak8974->regs[0].supply = ak8974_reg_avdd; 840 ak8974->regs[1].supply = ak8974_reg_dvdd; 841 842 ret = devm_regulator_bulk_get(&i2c->dev, 843 ARRAY_SIZE(ak8974->regs), 844 ak8974->regs); 845 if (ret < 0) 846 return dev_err_probe(&i2c->dev, ret, "cannot get regulators\n"); 847 848 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 849 if (ret < 0) { 850 dev_err(&i2c->dev, "cannot enable regulators\n"); 851 return ret; 852 } 853 854 /* Take runtime PM online */ 855 pm_runtime_get_noresume(&i2c->dev); 856 pm_runtime_set_active(&i2c->dev); 857 pm_runtime_enable(&i2c->dev); 858 859 ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config); 860 if (IS_ERR(ak8974->map)) { 861 dev_err(&i2c->dev, "failed to allocate register map\n"); 862 pm_runtime_put_noidle(&i2c->dev); 863 pm_runtime_disable(&i2c->dev); 864 return PTR_ERR(ak8974->map); 865 } 866 867 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 868 if (ret) { 869 dev_err(&i2c->dev, "could not power on\n"); 870 goto disable_pm; 871 } 872 873 ret = ak8974_detect(ak8974); 874 if (ret) { 875 dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n"); 876 goto disable_pm; 877 } 878 879 ret = ak8974_selftest(ak8974); 880 if (ret) 881 dev_err(&i2c->dev, "selftest failed (continuing anyway)\n"); 882 883 ret = ak8974_reset(ak8974); 884 if (ret) { 885 dev_err(&i2c->dev, "AK8974 reset failed\n"); 886 goto disable_pm; 887 } 888 889 switch (ak8974->variant) { 890 case AK8974_WHOAMI_VALUE_AMI306: 891 case AK8974_WHOAMI_VALUE_AMI305: 892 indio_dev->channels = ak8974_12_bits_channels; 893 indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels); 894 break; 895 case AK8974_WHOAMI_VALUE_HSCDTD008A: 896 indio_dev->channels = ak8974_15_bits_channels; 897 indio_dev->num_channels = ARRAY_SIZE(ak8974_15_bits_channels); 898 break; 899 default: 900 indio_dev->channels = ak8974_12_bits_channels; 901 indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels); 902 break; 903 } 904 indio_dev->info = &ak8974_info; 905 indio_dev->available_scan_masks = ak8974_scan_masks; 906 indio_dev->modes = INDIO_DIRECT_MODE; 907 indio_dev->name = ak8974->name; 908 909 ret = iio_triggered_buffer_setup(indio_dev, NULL, 910 ak8974_handle_trigger, 911 NULL); 912 if (ret) { 913 dev_err(&i2c->dev, "triggered buffer setup failed\n"); 914 goto disable_pm; 915 } 916 917 /* If we have a valid DRDY IRQ, make use of it */ 918 if (irq > 0) { 919 irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq)); 920 if (irq_trig == IRQF_TRIGGER_RISING) { 921 dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n"); 922 } else if (irq_trig == IRQF_TRIGGER_FALLING) { 923 ak8974->drdy_active_low = true; 924 dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n"); 925 } else { 926 irq_trig = IRQF_TRIGGER_RISING; 927 } 928 irq_trig |= IRQF_ONESHOT; 929 irq_trig |= IRQF_SHARED; 930 931 ret = devm_request_threaded_irq(&i2c->dev, 932 irq, 933 ak8974_drdy_irq, 934 ak8974_drdy_irq_thread, 935 irq_trig, 936 ak8974->name, 937 ak8974); 938 if (ret) { 939 dev_err(&i2c->dev, "unable to request DRDY IRQ " 940 "- proceeding without IRQ\n"); 941 goto no_irq; 942 } 943 ak8974->drdy_irq = true; 944 } 945 946no_irq: 947 ret = iio_device_register(indio_dev); 948 if (ret) { 949 dev_err(&i2c->dev, "device register failed\n"); 950 goto cleanup_buffer; 951 } 952 953 pm_runtime_set_autosuspend_delay(&i2c->dev, 954 AK8974_AUTOSUSPEND_DELAY); 955 pm_runtime_use_autosuspend(&i2c->dev); 956 pm_runtime_put(&i2c->dev); 957 958 return 0; 959 960cleanup_buffer: 961 iio_triggered_buffer_cleanup(indio_dev); 962disable_pm: 963 pm_runtime_put_noidle(&i2c->dev); 964 pm_runtime_disable(&i2c->dev); 965 ak8974_set_power(ak8974, AK8974_PWR_OFF); 966 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 967 968 return ret; 969} 970 971static void ak8974_remove(struct i2c_client *i2c) 972{ 973 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 974 struct ak8974 *ak8974 = iio_priv(indio_dev); 975 976 iio_device_unregister(indio_dev); 977 iio_triggered_buffer_cleanup(indio_dev); 978 pm_runtime_get_sync(&i2c->dev); 979 pm_runtime_put_noidle(&i2c->dev); 980 pm_runtime_disable(&i2c->dev); 981 ak8974_set_power(ak8974, AK8974_PWR_OFF); 982 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 983} 984 985static int ak8974_runtime_suspend(struct device *dev) 986{ 987 struct ak8974 *ak8974 = 988 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 989 990 ak8974_set_power(ak8974, AK8974_PWR_OFF); 991 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 992 993 return 0; 994} 995 996static int ak8974_runtime_resume(struct device *dev) 997{ 998 struct ak8974 *ak8974 = 999 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 1000 int ret; 1001 1002 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 1003 if (ret) 1004 return ret; 1005 msleep(AK8974_POWERON_DELAY); 1006 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 1007 if (ret) 1008 goto out_regulator_disable; 1009 1010 ret = ak8974_configure(ak8974); 1011 if (ret) 1012 goto out_disable_power; 1013 1014 return 0; 1015 1016out_disable_power: 1017 ak8974_set_power(ak8974, AK8974_PWR_OFF); 1018out_regulator_disable: 1019 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 1020 1021 return ret; 1022} 1023 1024static DEFINE_RUNTIME_DEV_PM_OPS(ak8974_dev_pm_ops, ak8974_runtime_suspend, 1025 ak8974_runtime_resume, NULL); 1026 1027static const struct i2c_device_id ak8974_id[] = { 1028 {"ami305", 0 }, 1029 {"ami306", 0 }, 1030 {"ak8974", 0 }, 1031 {"hscdtd008a", 0 }, 1032 {} 1033}; 1034MODULE_DEVICE_TABLE(i2c, ak8974_id); 1035 1036static const struct of_device_id ak8974_of_match[] = { 1037 { .compatible = "asahi-kasei,ak8974", }, 1038 { .compatible = "alps,hscdtd008a", }, 1039 {} 1040}; 1041MODULE_DEVICE_TABLE(of, ak8974_of_match); 1042 1043static struct i2c_driver ak8974_driver = { 1044 .driver = { 1045 .name = "ak8974", 1046 .pm = pm_ptr(&ak8974_dev_pm_ops), 1047 .of_match_table = ak8974_of_match, 1048 }, 1049 .probe = ak8974_probe, 1050 .remove = ak8974_remove, 1051 .id_table = ak8974_id, 1052}; 1053module_i2c_driver(ak8974_driver); 1054 1055MODULE_DESCRIPTION("AK8974 and AMI30x 3-axis magnetometer driver"); 1056MODULE_AUTHOR("Samu Onkalo"); 1057MODULE_AUTHOR("Linus Walleij"); 1058MODULE_LICENSE("GPL v2"); 1059