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/kernel.h> 16 #include <linux/i2c.h> 17 #include <linux/interrupt.h> 18 #include <linux/irq.h> /* For irq_get_irq_data() */ 19 #include <linux/completion.h> 20 #include <linux/err.h> 21 #include <linux/mutex.h> 22 #include <linux/delay.h> 23 #include <linux/bitops.h> 24 #include <linux/random.h> 25 #include <linux/regmap.h> 26 #include <linux/regulator/consumer.h> 27 #include <linux/pm_runtime.h> 28 29 #include <linux/iio/iio.h> 30 #include <linux/iio/sysfs.h> 31 #include <linux/iio/buffer.h> 32 #include <linux/iio/trigger.h> 33 #include <linux/iio/trigger_consumer.h> 34 #include <linux/iio/triggered_buffer.h> 35 36 /* 37 * 16-bit registers are little-endian. LSB is at the address defined below 38 * and MSB is at the next higher address. 39 */ 40 41 /* These registers are common for AK8974 and AMI30x */ 42 #define AK8974_SELFTEST 0x0C 43 #define AK8974_SELFTEST_IDLE 0x55 44 #define AK8974_SELFTEST_OK 0xAA 45 46 #define AK8974_INFO 0x0D 47 48 #define AK8974_WHOAMI 0x0F 49 #define AK8974_WHOAMI_VALUE_AMI306 0x46 50 #define AK8974_WHOAMI_VALUE_AMI305 0x47 51 #define AK8974_WHOAMI_VALUE_AK8974 0x48 52 #define AK8974_WHOAMI_VALUE_HSCDTD008A 0x49 53 54 #define AK8974_DATA_X 0x10 55 #define AK8974_DATA_Y 0x12 56 #define AK8974_DATA_Z 0x14 57 #define AK8974_INT_SRC 0x16 58 #define AK8974_STATUS 0x18 59 #define AK8974_INT_CLEAR 0x1A 60 #define AK8974_CTRL1 0x1B 61 #define AK8974_CTRL2 0x1C 62 #define AK8974_CTRL3 0x1D 63 #define AK8974_INT_CTRL 0x1E 64 #define AK8974_INT_THRES 0x26 /* Absolute any axis value threshold */ 65 #define AK8974_PRESET 0x30 66 67 /* AK8974-specific offsets */ 68 #define AK8974_OFFSET_X 0x20 69 #define AK8974_OFFSET_Y 0x22 70 #define AK8974_OFFSET_Z 0x24 71 /* AMI305-specific offsets */ 72 #define AMI305_OFFSET_X 0x6C 73 #define AMI305_OFFSET_Y 0x72 74 #define AMI305_OFFSET_Z 0x78 75 76 /* Different temperature registers */ 77 #define AK8974_TEMP 0x31 78 #define AMI305_TEMP 0x60 79 80 /* AMI306-specific control register */ 81 #define AMI306_CTRL4 0x5C 82 83 /* AMI306 factory calibration data */ 84 85 /* fine axis sensitivity */ 86 #define AMI306_FINEOUTPUT_X 0x90 87 #define AMI306_FINEOUTPUT_Y 0x92 88 #define AMI306_FINEOUTPUT_Z 0x94 89 90 /* axis sensitivity */ 91 #define AMI306_SENS_X 0x96 92 #define AMI306_SENS_Y 0x98 93 #define AMI306_SENS_Z 0x9A 94 95 /* axis cross-interference */ 96 #define AMI306_GAIN_PARA_XZ 0x9C 97 #define AMI306_GAIN_PARA_XY 0x9D 98 #define AMI306_GAIN_PARA_YZ 0x9E 99 #define AMI306_GAIN_PARA_YX 0x9F 100 #define AMI306_GAIN_PARA_ZY 0xA0 101 #define AMI306_GAIN_PARA_ZX 0xA1 102 103 /* offset at ZERO magnetic field */ 104 #define AMI306_OFFZERO_X 0xF8 105 #define AMI306_OFFZERO_Y 0xFA 106 #define AMI306_OFFZERO_Z 0xFC 107 108 109 #define AK8974_INT_X_HIGH BIT(7) /* Axis over +threshold */ 110 #define AK8974_INT_Y_HIGH BIT(6) 111 #define AK8974_INT_Z_HIGH BIT(5) 112 #define AK8974_INT_X_LOW BIT(4) /* Axis below -threshold */ 113 #define AK8974_INT_Y_LOW BIT(3) 114 #define AK8974_INT_Z_LOW BIT(2) 115 #define AK8974_INT_RANGE BIT(1) /* Range overflow (any axis) */ 116 117 #define AK8974_STATUS_DRDY BIT(6) /* Data ready */ 118 #define AK8974_STATUS_OVERRUN BIT(5) /* Data overrun */ 119 #define AK8974_STATUS_INT BIT(4) /* Interrupt occurred */ 120 121 #define AK8974_CTRL1_POWER BIT(7) /* 0 = standby; 1 = active */ 122 #define AK8974_CTRL1_RATE BIT(4) /* 0 = 10 Hz; 1 = 20 Hz */ 123 #define AK8974_CTRL1_FORCE_EN BIT(1) /* 0 = normal; 1 = force */ 124 #define AK8974_CTRL1_MODE2 BIT(0) /* 0 */ 125 126 #define AK8974_CTRL2_INT_EN BIT(4) /* 1 = enable interrupts */ 127 #define AK8974_CTRL2_DRDY_EN BIT(3) /* 1 = enable data ready signal */ 128 #define AK8974_CTRL2_DRDY_POL BIT(2) /* 1 = data ready active high */ 129 #define AK8974_CTRL2_RESDEF (AK8974_CTRL2_DRDY_POL) 130 131 #define AK8974_CTRL3_RESET BIT(7) /* Software reset */ 132 #define AK8974_CTRL3_FORCE BIT(6) /* Start forced measurement */ 133 #define AK8974_CTRL3_SELFTEST BIT(4) /* Set selftest register */ 134 #define AK8974_CTRL3_RESDEF 0x00 135 136 #define AK8974_INT_CTRL_XEN BIT(7) /* Enable interrupt for this axis */ 137 #define AK8974_INT_CTRL_YEN BIT(6) 138 #define AK8974_INT_CTRL_ZEN BIT(5) 139 #define AK8974_INT_CTRL_XYZEN (BIT(7)|BIT(6)|BIT(5)) 140 #define AK8974_INT_CTRL_POL BIT(3) /* 0 = active low; 1 = active high */ 141 #define AK8974_INT_CTRL_PULSE BIT(1) /* 0 = latched; 1 = pulse (50 usec) */ 142 #define AK8974_INT_CTRL_RESDEF (AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL) 143 144 /* HSCDTD008A-specific control register */ 145 #define HSCDTD008A_CTRL4 0x1E 146 #define HSCDTD008A_CTRL4_MMD BIT(7) /* must be set to 1 */ 147 #define HSCDTD008A_CTRL4_RANGE BIT(4) /* 0 = 14-bit output; 1 = 15-bit output */ 148 #define HSCDTD008A_CTRL4_RESDEF (HSCDTD008A_CTRL4_MMD | HSCDTD008A_CTRL4_RANGE) 149 150 /* The AMI305 has elaborate FW version and serial number registers */ 151 #define AMI305_VER 0xE8 152 #define AMI305_SN 0xEA 153 154 #define AK8974_MAX_RANGE 2048 155 156 #define AK8974_POWERON_DELAY 50 157 #define AK8974_ACTIVATE_DELAY 1 158 #define AK8974_SELFTEST_DELAY 1 159 /* 160 * Set the autosuspend to two orders of magnitude larger than the poweron 161 * delay to make sane reasonable power tradeoff savings (5 seconds in 162 * this case). 163 */ 164 #define AK8974_AUTOSUSPEND_DELAY 5000 165 166 #define AK8974_MEASTIME 3 167 168 #define AK8974_PWR_ON 1 169 #define AK8974_PWR_OFF 0 170 171 /** 172 * struct ak8974 - state container for the AK8974 driver 173 * @i2c: parent I2C client 174 * @orientation: mounting matrix, flipped axis etc 175 * @map: regmap to access the AK8974 registers over I2C 176 * @regs: the avdd and dvdd power regulators 177 * @name: the name of the part 178 * @variant: the whoami ID value (for selecting code paths) 179 * @lock: locks the magnetometer for exclusive use during a measurement 180 * @drdy_irq: uses the DRDY IRQ line 181 * @drdy_complete: completion for DRDY 182 * @drdy_active_low: the DRDY IRQ is active low 183 */ 184 struct ak8974 { 185 struct i2c_client *i2c; 186 struct iio_mount_matrix orientation; 187 struct regmap *map; 188 struct regulator_bulk_data regs[2]; 189 const char *name; 190 u8 variant; 191 struct mutex lock; 192 bool drdy_irq; 193 struct completion drdy_complete; 194 bool drdy_active_low; 195 }; 196 197 static const char ak8974_reg_avdd[] = "avdd"; 198 static const char ak8974_reg_dvdd[] = "dvdd"; 199 200 static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val) 201 { 202 int ret; 203 __le16 bulk; 204 205 ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2); 206 if (ret) 207 return ret; 208 *val = le16_to_cpu(bulk); 209 210 return 0; 211 } 212 213 static int ak8974_set_u16_val(struct ak8974 *ak8974, u8 reg, u16 val) 214 { 215 __le16 bulk = cpu_to_le16(val); 216 217 return regmap_bulk_write(ak8974->map, reg, &bulk, 2); 218 } 219 220 static int ak8974_set_power(struct ak8974 *ak8974, bool mode) 221 { 222 int ret; 223 u8 val; 224 225 val = mode ? AK8974_CTRL1_POWER : 0; 226 val |= AK8974_CTRL1_FORCE_EN; 227 ret = regmap_write(ak8974->map, AK8974_CTRL1, val); 228 if (ret < 0) 229 return ret; 230 231 if (mode) 232 msleep(AK8974_ACTIVATE_DELAY); 233 234 return 0; 235 } 236 237 static int ak8974_reset(struct ak8974 *ak8974) 238 { 239 int ret; 240 241 /* Power on to get register access. Sets CTRL1 reg to reset state */ 242 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 243 if (ret) 244 return ret; 245 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF); 246 if (ret) 247 return ret; 248 ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF); 249 if (ret) 250 return ret; 251 if (ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A) { 252 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, 253 AK8974_INT_CTRL_RESDEF); 254 if (ret) 255 return ret; 256 } else { 257 ret = regmap_write(ak8974->map, HSCDTD008A_CTRL4, 258 HSCDTD008A_CTRL4_RESDEF); 259 if (ret) 260 return ret; 261 } 262 263 /* After reset, power off is default state */ 264 return ak8974_set_power(ak8974, AK8974_PWR_OFF); 265 } 266 267 static int ak8974_configure(struct ak8974 *ak8974) 268 { 269 int ret; 270 271 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN | 272 AK8974_CTRL2_INT_EN); 273 if (ret) 274 return ret; 275 ret = regmap_write(ak8974->map, AK8974_CTRL3, 0); 276 if (ret) 277 return ret; 278 if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI306) { 279 /* magic from datasheet: set high-speed measurement mode */ 280 ret = ak8974_set_u16_val(ak8974, AMI306_CTRL4, 0xA07E); 281 if (ret) 282 return ret; 283 } 284 if (ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A) 285 return 0; 286 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL); 287 if (ret) 288 return ret; 289 290 return regmap_write(ak8974->map, AK8974_PRESET, 0); 291 } 292 293 static int ak8974_trigmeas(struct ak8974 *ak8974) 294 { 295 unsigned int clear; 296 u8 mask; 297 u8 val; 298 int ret; 299 300 /* Clear any previous measurement overflow status */ 301 ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear); 302 if (ret) 303 return ret; 304 305 /* If we have a DRDY IRQ line, use it */ 306 if (ak8974->drdy_irq) { 307 mask = AK8974_CTRL2_INT_EN | 308 AK8974_CTRL2_DRDY_EN | 309 AK8974_CTRL2_DRDY_POL; 310 val = AK8974_CTRL2_DRDY_EN; 311 312 if (!ak8974->drdy_active_low) 313 val |= AK8974_CTRL2_DRDY_POL; 314 315 init_completion(&ak8974->drdy_complete); 316 ret = regmap_update_bits(ak8974->map, AK8974_CTRL2, 317 mask, val); 318 if (ret) 319 return ret; 320 } 321 322 /* Force a measurement */ 323 return regmap_update_bits(ak8974->map, 324 AK8974_CTRL3, 325 AK8974_CTRL3_FORCE, 326 AK8974_CTRL3_FORCE); 327 } 328 329 static int ak8974_await_drdy(struct ak8974 *ak8974) 330 { 331 int timeout = 2; 332 unsigned int val; 333 int ret; 334 335 if (ak8974->drdy_irq) { 336 ret = wait_for_completion_timeout(&ak8974->drdy_complete, 337 1 + msecs_to_jiffies(1000)); 338 if (!ret) { 339 dev_err(&ak8974->i2c->dev, 340 "timeout waiting for DRDY IRQ\n"); 341 return -ETIMEDOUT; 342 } 343 return 0; 344 } 345 346 /* Default delay-based poll loop */ 347 do { 348 msleep(AK8974_MEASTIME); 349 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 350 if (ret < 0) 351 return ret; 352 if (val & AK8974_STATUS_DRDY) 353 return 0; 354 } while (--timeout); 355 356 dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n"); 357 return -ETIMEDOUT; 358 } 359 360 static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result) 361 { 362 unsigned int src; 363 int ret; 364 365 ret = ak8974_await_drdy(ak8974); 366 if (ret) 367 return ret; 368 ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src); 369 if (ret < 0) 370 return ret; 371 372 /* Out of range overflow! Strong magnet close? */ 373 if (src & AK8974_INT_RANGE) { 374 dev_err(&ak8974->i2c->dev, 375 "range overflow in sensor\n"); 376 return -ERANGE; 377 } 378 379 ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6); 380 if (ret) 381 return ret; 382 383 return ret; 384 } 385 386 static irqreturn_t ak8974_drdy_irq(int irq, void *d) 387 { 388 struct ak8974 *ak8974 = d; 389 390 if (!ak8974->drdy_irq) 391 return IRQ_NONE; 392 393 /* TODO: timestamp here to get good measurement stamps */ 394 return IRQ_WAKE_THREAD; 395 } 396 397 static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d) 398 { 399 struct ak8974 *ak8974 = d; 400 unsigned int val; 401 int ret; 402 403 /* Check if this was a DRDY from us */ 404 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 405 if (ret < 0) { 406 dev_err(&ak8974->i2c->dev, "error reading DRDY status\n"); 407 return IRQ_HANDLED; 408 } 409 if (val & AK8974_STATUS_DRDY) { 410 /* Yes this was our IRQ */ 411 complete(&ak8974->drdy_complete); 412 return IRQ_HANDLED; 413 } 414 415 /* We may be on a shared IRQ, let the next client check */ 416 return IRQ_NONE; 417 } 418 419 static int ak8974_selftest(struct ak8974 *ak8974) 420 { 421 struct device *dev = &ak8974->i2c->dev; 422 unsigned int val; 423 int ret; 424 425 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 426 if (ret) 427 return ret; 428 if (val != AK8974_SELFTEST_IDLE) { 429 dev_err(dev, "selftest not idle before test\n"); 430 return -EIO; 431 } 432 433 /* Trigger self-test */ 434 ret = regmap_update_bits(ak8974->map, 435 AK8974_CTRL3, 436 AK8974_CTRL3_SELFTEST, 437 AK8974_CTRL3_SELFTEST); 438 if (ret) { 439 dev_err(dev, "could not write CTRL3\n"); 440 return ret; 441 } 442 443 msleep(AK8974_SELFTEST_DELAY); 444 445 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 446 if (ret) 447 return ret; 448 if (val != AK8974_SELFTEST_OK) { 449 dev_err(dev, "selftest result NOT OK (%02x)\n", val); 450 return -EIO; 451 } 452 453 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 454 if (ret) 455 return ret; 456 if (val != AK8974_SELFTEST_IDLE) { 457 dev_err(dev, "selftest not idle after test (%02x)\n", val); 458 return -EIO; 459 } 460 dev_dbg(dev, "passed self-test\n"); 461 462 return 0; 463 } 464 465 static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg, 466 __le16 *tab, size_t tab_size) 467 { 468 int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size); 469 if (ret) { 470 memset(tab, 0xFF, tab_size); 471 dev_warn(&ak8974->i2c->dev, 472 "can't read calibration data (regs %u..%zu): %d\n", 473 reg, reg + tab_size - 1, ret); 474 } else { 475 add_device_randomness(tab, tab_size); 476 } 477 } 478 479 static int ak8974_detect(struct ak8974 *ak8974) 480 { 481 unsigned int whoami; 482 const char *name; 483 int ret; 484 unsigned int fw; 485 u16 sn; 486 487 ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami); 488 if (ret) 489 return ret; 490 491 name = "ami305"; 492 493 switch (whoami) { 494 case AK8974_WHOAMI_VALUE_AMI306: 495 name = "ami306"; 496 /* fall-through */ 497 case AK8974_WHOAMI_VALUE_AMI305: 498 ret = regmap_read(ak8974->map, AMI305_VER, &fw); 499 if (ret) 500 return ret; 501 fw &= 0x7f; /* only bits 0 thru 6 valid */ 502 ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn); 503 if (ret) 504 return ret; 505 add_device_randomness(&sn, sizeof(sn)); 506 dev_info(&ak8974->i2c->dev, 507 "detected %s, FW ver %02x, S/N: %04x\n", 508 name, fw, sn); 509 break; 510 case AK8974_WHOAMI_VALUE_AK8974: 511 name = "ak8974"; 512 dev_info(&ak8974->i2c->dev, "detected AK8974\n"); 513 break; 514 case AK8974_WHOAMI_VALUE_HSCDTD008A: 515 name = "hscdtd008a"; 516 dev_info(&ak8974->i2c->dev, "detected hscdtd008a\n"); 517 break; 518 default: 519 dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ", 520 whoami); 521 return -ENODEV; 522 } 523 524 ak8974->name = name; 525 ak8974->variant = whoami; 526 527 if (whoami == AK8974_WHOAMI_VALUE_AMI306) { 528 __le16 fab_data1[9], fab_data2[3]; 529 int i; 530 531 ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X, 532 fab_data1, sizeof(fab_data1)); 533 ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X, 534 fab_data2, sizeof(fab_data2)); 535 536 for (i = 0; i < 3; ++i) { 537 static const char axis[3] = "XYZ"; 538 static const char pgaxis[6] = "ZYZXYX"; 539 unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F; 540 unsigned fine = le16_to_cpu(fab_data1[i]); 541 unsigned sens = le16_to_cpu(fab_data1[i + 3]); 542 unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]); 543 unsigned pgain2 = pgain1 >> 8; 544 545 pgain1 &= 0xFF; 546 547 dev_info(&ak8974->i2c->dev, 548 "factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n", 549 axis[i], offz, sens, fine, pgaxis[i * 2], 550 pgain1, pgaxis[i * 2 + 1], pgain2); 551 } 552 } 553 554 return 0; 555 } 556 557 static int ak8974_measure_channel(struct ak8974 *ak8974, unsigned long address, 558 int *val) 559 { 560 __le16 hw_values[3]; 561 int ret; 562 563 pm_runtime_get_sync(&ak8974->i2c->dev); 564 mutex_lock(&ak8974->lock); 565 566 /* 567 * We read all axes and discard all but one, for optimized 568 * reading, use the triggered buffer. 569 */ 570 ret = ak8974_trigmeas(ak8974); 571 if (ret) 572 goto out_unlock; 573 ret = ak8974_getresult(ak8974, hw_values); 574 if (ret) 575 goto out_unlock; 576 /* 577 * This explicit cast to (s16) is necessary as the measurement 578 * is done in 2's complement with positive and negative values. 579 * The follwing assignment to *val will then convert the signed 580 * s16 value to a signed int value. 581 */ 582 *val = (s16)le16_to_cpu(hw_values[address]); 583 out_unlock: 584 mutex_unlock(&ak8974->lock); 585 pm_runtime_mark_last_busy(&ak8974->i2c->dev); 586 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 587 588 return ret; 589 } 590 591 static int ak8974_read_raw(struct iio_dev *indio_dev, 592 struct iio_chan_spec const *chan, 593 int *val, int *val2, 594 long mask) 595 { 596 struct ak8974 *ak8974 = iio_priv(indio_dev); 597 int ret; 598 599 switch (mask) { 600 case IIO_CHAN_INFO_RAW: 601 if (chan->address > 2) { 602 dev_err(&ak8974->i2c->dev, "faulty channel address\n"); 603 return -EIO; 604 } 605 ret = ak8974_measure_channel(ak8974, chan->address, val); 606 if (ret) 607 return ret; 608 return IIO_VAL_INT; 609 case IIO_CHAN_INFO_SCALE: 610 switch (ak8974->variant) { 611 case AK8974_WHOAMI_VALUE_AMI306: 612 case AK8974_WHOAMI_VALUE_AMI305: 613 /* 614 * The datasheet for AMI305 and AMI306, page 6 615 * specifies the range of the sensor to be 616 * +/- 12 Gauss. 617 */ 618 *val = 12; 619 /* 620 * 12 bits are used, +/- 2^11 621 * [ -2048 .. 2047 ] (manual page 20) 622 * [ 0xf800 .. 0x07ff ] 623 */ 624 *val2 = 11; 625 return IIO_VAL_FRACTIONAL_LOG2; 626 case AK8974_WHOAMI_VALUE_HSCDTD008A: 627 /* 628 * The datasheet for HSCDTF008A, page 3 specifies the 629 * range of the sensor as +/- 2.4 mT per axis, which 630 * corresponds to +/- 2400 uT = +/- 24 Gauss. 631 */ 632 *val = 24; 633 /* 634 * 15 bits are used (set up in CTRL4), +/- 2^14 635 * [ -16384 .. 16383 ] (manual page 24) 636 * [ 0xc000 .. 0x3fff ] 637 */ 638 *val2 = 14; 639 return IIO_VAL_FRACTIONAL_LOG2; 640 default: 641 /* GUESSING +/- 12 Gauss */ 642 *val = 12; 643 /* GUESSING 12 bits ADC +/- 2^11 */ 644 *val2 = 11; 645 return IIO_VAL_FRACTIONAL_LOG2; 646 } 647 break; 648 default: 649 /* Unknown request */ 650 break; 651 } 652 653 return -EINVAL; 654 } 655 656 static void ak8974_fill_buffer(struct iio_dev *indio_dev) 657 { 658 struct ak8974 *ak8974 = iio_priv(indio_dev); 659 int ret; 660 __le16 hw_values[8]; /* Three axes + 64bit padding */ 661 662 pm_runtime_get_sync(&ak8974->i2c->dev); 663 mutex_lock(&ak8974->lock); 664 665 ret = ak8974_trigmeas(ak8974); 666 if (ret) { 667 dev_err(&ak8974->i2c->dev, "error triggering measure\n"); 668 goto out_unlock; 669 } 670 ret = ak8974_getresult(ak8974, hw_values); 671 if (ret) { 672 dev_err(&ak8974->i2c->dev, "error getting measures\n"); 673 goto out_unlock; 674 } 675 676 iio_push_to_buffers_with_timestamp(indio_dev, hw_values, 677 iio_get_time_ns(indio_dev)); 678 679 out_unlock: 680 mutex_unlock(&ak8974->lock); 681 pm_runtime_mark_last_busy(&ak8974->i2c->dev); 682 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 683 } 684 685 static irqreturn_t ak8974_handle_trigger(int irq, void *p) 686 { 687 const struct iio_poll_func *pf = p; 688 struct iio_dev *indio_dev = pf->indio_dev; 689 690 ak8974_fill_buffer(indio_dev); 691 iio_trigger_notify_done(indio_dev->trig); 692 693 return IRQ_HANDLED; 694 } 695 696 static const struct iio_mount_matrix * 697 ak8974_get_mount_matrix(const struct iio_dev *indio_dev, 698 const struct iio_chan_spec *chan) 699 { 700 struct ak8974 *ak8974 = iio_priv(indio_dev); 701 702 return &ak8974->orientation; 703 } 704 705 static const struct iio_chan_spec_ext_info ak8974_ext_info[] = { 706 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix), 707 { }, 708 }; 709 710 #define AK8974_AXIS_CHANNEL(axis, index, bits) \ 711 { \ 712 .type = IIO_MAGN, \ 713 .modified = 1, \ 714 .channel2 = IIO_MOD_##axis, \ 715 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 716 BIT(IIO_CHAN_INFO_SCALE), \ 717 .ext_info = ak8974_ext_info, \ 718 .address = index, \ 719 .scan_index = index, \ 720 .scan_type = { \ 721 .sign = 's', \ 722 .realbits = bits, \ 723 .storagebits = 16, \ 724 .endianness = IIO_LE \ 725 }, \ 726 } 727 728 /* 729 * We have no datasheet for the AK8974 but we guess that its 730 * ADC is 12 bits. The AMI305 and AMI306 certainly has 12bit 731 * ADC. 732 */ 733 static const struct iio_chan_spec ak8974_12_bits_channels[] = { 734 AK8974_AXIS_CHANNEL(X, 0, 12), 735 AK8974_AXIS_CHANNEL(Y, 1, 12), 736 AK8974_AXIS_CHANNEL(Z, 2, 12), 737 IIO_CHAN_SOFT_TIMESTAMP(3), 738 }; 739 740 /* 741 * The HSCDTD008A has 15 bits resolution the way we set it up 742 * in CTRL4. 743 */ 744 static const struct iio_chan_spec ak8974_15_bits_channels[] = { 745 AK8974_AXIS_CHANNEL(X, 0, 15), 746 AK8974_AXIS_CHANNEL(Y, 1, 15), 747 AK8974_AXIS_CHANNEL(Z, 2, 15), 748 IIO_CHAN_SOFT_TIMESTAMP(3), 749 }; 750 751 static const unsigned long ak8974_scan_masks[] = { 0x7, 0 }; 752 753 static const struct iio_info ak8974_info = { 754 .read_raw = &ak8974_read_raw, 755 }; 756 757 static bool ak8974_writeable_reg(struct device *dev, unsigned int reg) 758 { 759 struct i2c_client *i2c = to_i2c_client(dev); 760 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 761 struct ak8974 *ak8974 = iio_priv(indio_dev); 762 763 switch (reg) { 764 case AK8974_CTRL1: 765 case AK8974_CTRL2: 766 case AK8974_CTRL3: 767 case AK8974_INT_CTRL: 768 case AK8974_INT_THRES: 769 case AK8974_INT_THRES + 1: 770 return true; 771 case AK8974_PRESET: 772 case AK8974_PRESET + 1: 773 return ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A; 774 case AK8974_OFFSET_X: 775 case AK8974_OFFSET_X + 1: 776 case AK8974_OFFSET_Y: 777 case AK8974_OFFSET_Y + 1: 778 case AK8974_OFFSET_Z: 779 case AK8974_OFFSET_Z + 1: 780 return ak8974->variant == AK8974_WHOAMI_VALUE_AK8974 || 781 ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A; 782 case AMI305_OFFSET_X: 783 case AMI305_OFFSET_X + 1: 784 case AMI305_OFFSET_Y: 785 case AMI305_OFFSET_Y + 1: 786 case AMI305_OFFSET_Z: 787 case AMI305_OFFSET_Z + 1: 788 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 || 789 ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; 790 case AMI306_CTRL4: 791 case AMI306_CTRL4 + 1: 792 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; 793 default: 794 return false; 795 } 796 } 797 798 static bool ak8974_precious_reg(struct device *dev, unsigned int reg) 799 { 800 return reg == AK8974_INT_CLEAR; 801 } 802 803 static const struct regmap_config ak8974_regmap_config = { 804 .reg_bits = 8, 805 .val_bits = 8, 806 .max_register = 0xff, 807 .writeable_reg = ak8974_writeable_reg, 808 .precious_reg = ak8974_precious_reg, 809 }; 810 811 static int ak8974_probe(struct i2c_client *i2c, 812 const struct i2c_device_id *id) 813 { 814 struct iio_dev *indio_dev; 815 struct ak8974 *ak8974; 816 unsigned long irq_trig; 817 int irq = i2c->irq; 818 int ret; 819 820 /* Register with IIO */ 821 indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974)); 822 if (indio_dev == NULL) 823 return -ENOMEM; 824 825 ak8974 = iio_priv(indio_dev); 826 i2c_set_clientdata(i2c, indio_dev); 827 ak8974->i2c = i2c; 828 mutex_init(&ak8974->lock); 829 830 ret = iio_read_mount_matrix(&i2c->dev, "mount-matrix", 831 &ak8974->orientation); 832 if (ret) 833 return ret; 834 835 ak8974->regs[0].supply = ak8974_reg_avdd; 836 ak8974->regs[1].supply = ak8974_reg_dvdd; 837 838 ret = devm_regulator_bulk_get(&i2c->dev, 839 ARRAY_SIZE(ak8974->regs), 840 ak8974->regs); 841 if (ret < 0) { 842 if (ret != -EPROBE_DEFER) 843 dev_err(&i2c->dev, "cannot get regulators: %d\n", ret); 844 else 845 dev_dbg(&i2c->dev, 846 "regulators unavailable, deferring probe\n"); 847 848 return ret; 849 } 850 851 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 852 if (ret < 0) { 853 dev_err(&i2c->dev, "cannot enable regulators\n"); 854 return ret; 855 } 856 857 /* Take runtime PM online */ 858 pm_runtime_get_noresume(&i2c->dev); 859 pm_runtime_set_active(&i2c->dev); 860 pm_runtime_enable(&i2c->dev); 861 862 ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config); 863 if (IS_ERR(ak8974->map)) { 864 dev_err(&i2c->dev, "failed to allocate register map\n"); 865 return PTR_ERR(ak8974->map); 866 } 867 868 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 869 if (ret) { 870 dev_err(&i2c->dev, "could not power on\n"); 871 goto power_off; 872 } 873 874 ret = ak8974_detect(ak8974); 875 if (ret) { 876 dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n"); 877 goto power_off; 878 } 879 880 ret = ak8974_selftest(ak8974); 881 if (ret) 882 dev_err(&i2c->dev, "selftest failed (continuing anyway)\n"); 883 884 ret = ak8974_reset(ak8974); 885 if (ret) { 886 dev_err(&i2c->dev, "AK8974 reset failed\n"); 887 goto power_off; 888 } 889 890 pm_runtime_set_autosuspend_delay(&i2c->dev, 891 AK8974_AUTOSUSPEND_DELAY); 892 pm_runtime_use_autosuspend(&i2c->dev); 893 pm_runtime_put(&i2c->dev); 894 895 indio_dev->dev.parent = &i2c->dev; 896 switch (ak8974->variant) { 897 case AK8974_WHOAMI_VALUE_AMI306: 898 case AK8974_WHOAMI_VALUE_AMI305: 899 indio_dev->channels = ak8974_12_bits_channels; 900 indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels); 901 break; 902 case AK8974_WHOAMI_VALUE_HSCDTD008A: 903 indio_dev->channels = ak8974_15_bits_channels; 904 indio_dev->num_channels = ARRAY_SIZE(ak8974_15_bits_channels); 905 break; 906 default: 907 indio_dev->channels = ak8974_12_bits_channels; 908 indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels); 909 break; 910 } 911 indio_dev->info = &ak8974_info; 912 indio_dev->available_scan_masks = ak8974_scan_masks; 913 indio_dev->modes = INDIO_DIRECT_MODE; 914 indio_dev->name = ak8974->name; 915 916 ret = iio_triggered_buffer_setup(indio_dev, NULL, 917 ak8974_handle_trigger, 918 NULL); 919 if (ret) { 920 dev_err(&i2c->dev, "triggered buffer setup failed\n"); 921 goto disable_pm; 922 } 923 924 /* If we have a valid DRDY IRQ, make use of it */ 925 if (irq > 0) { 926 irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq)); 927 if (irq_trig == IRQF_TRIGGER_RISING) { 928 dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n"); 929 } else if (irq_trig == IRQF_TRIGGER_FALLING) { 930 ak8974->drdy_active_low = true; 931 dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n"); 932 } else { 933 irq_trig = IRQF_TRIGGER_RISING; 934 } 935 irq_trig |= IRQF_ONESHOT; 936 irq_trig |= IRQF_SHARED; 937 938 ret = devm_request_threaded_irq(&i2c->dev, 939 irq, 940 ak8974_drdy_irq, 941 ak8974_drdy_irq_thread, 942 irq_trig, 943 ak8974->name, 944 ak8974); 945 if (ret) { 946 dev_err(&i2c->dev, "unable to request DRDY IRQ " 947 "- proceeding without IRQ\n"); 948 goto no_irq; 949 } 950 ak8974->drdy_irq = true; 951 } 952 953 no_irq: 954 ret = iio_device_register(indio_dev); 955 if (ret) { 956 dev_err(&i2c->dev, "device register failed\n"); 957 goto cleanup_buffer; 958 } 959 960 return 0; 961 962 cleanup_buffer: 963 iio_triggered_buffer_cleanup(indio_dev); 964 disable_pm: 965 pm_runtime_put_noidle(&i2c->dev); 966 pm_runtime_disable(&i2c->dev); 967 ak8974_set_power(ak8974, AK8974_PWR_OFF); 968 power_off: 969 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 970 971 return ret; 972 } 973 974 static int ak8974_remove(struct i2c_client *i2c) 975 { 976 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 977 struct ak8974 *ak8974 = iio_priv(indio_dev); 978 979 iio_device_unregister(indio_dev); 980 iio_triggered_buffer_cleanup(indio_dev); 981 pm_runtime_get_sync(&i2c->dev); 982 pm_runtime_put_noidle(&i2c->dev); 983 pm_runtime_disable(&i2c->dev); 984 ak8974_set_power(ak8974, AK8974_PWR_OFF); 985 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 986 987 return 0; 988 } 989 990 static int __maybe_unused ak8974_runtime_suspend(struct device *dev) 991 { 992 struct ak8974 *ak8974 = 993 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 994 995 ak8974_set_power(ak8974, AK8974_PWR_OFF); 996 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 997 998 return 0; 999 } 1000 1001 static int __maybe_unused ak8974_runtime_resume(struct device *dev) 1002 { 1003 struct ak8974 *ak8974 = 1004 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 1005 int ret; 1006 1007 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 1008 if (ret) 1009 return ret; 1010 msleep(AK8974_POWERON_DELAY); 1011 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 1012 if (ret) 1013 goto out_regulator_disable; 1014 1015 ret = ak8974_configure(ak8974); 1016 if (ret) 1017 goto out_disable_power; 1018 1019 return 0; 1020 1021 out_disable_power: 1022 ak8974_set_power(ak8974, AK8974_PWR_OFF); 1023 out_regulator_disable: 1024 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 1025 1026 return ret; 1027 } 1028 1029 static const struct dev_pm_ops ak8974_dev_pm_ops = { 1030 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, 1031 pm_runtime_force_resume) 1032 SET_RUNTIME_PM_OPS(ak8974_runtime_suspend, 1033 ak8974_runtime_resume, NULL) 1034 }; 1035 1036 static const struct i2c_device_id ak8974_id[] = { 1037 {"ami305", 0 }, 1038 {"ami306", 0 }, 1039 {"ak8974", 0 }, 1040 {"hscdtd008a", 0 }, 1041 {} 1042 }; 1043 MODULE_DEVICE_TABLE(i2c, ak8974_id); 1044 1045 static const struct of_device_id ak8974_of_match[] = { 1046 { .compatible = "asahi-kasei,ak8974", }, 1047 { .compatible = "alps,hscdtd008a", }, 1048 {} 1049 }; 1050 MODULE_DEVICE_TABLE(of, ak8974_of_match); 1051 1052 static struct i2c_driver ak8974_driver = { 1053 .driver = { 1054 .name = "ak8974", 1055 .pm = &ak8974_dev_pm_ops, 1056 .of_match_table = of_match_ptr(ak8974_of_match), 1057 }, 1058 .probe = ak8974_probe, 1059 .remove = ak8974_remove, 1060 .id_table = ak8974_id, 1061 }; 1062 module_i2c_driver(ak8974_driver); 1063 1064 MODULE_DESCRIPTION("AK8974 and AMI30x 3-axis magnetometer driver"); 1065 MODULE_AUTHOR("Samu Onkalo"); 1066 MODULE_AUTHOR("Linus Walleij"); 1067 MODULE_LICENSE("GPL v2"); 1068