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 /* Ensure timestamp is naturally aligned */ 196 struct { 197 __le16 channels[3]; 198 s64 ts __aligned(8); 199 } scan; 200 }; 201 202 static const char ak8974_reg_avdd[] = "avdd"; 203 static const char ak8974_reg_dvdd[] = "dvdd"; 204 205 static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val) 206 { 207 int ret; 208 __le16 bulk; 209 210 ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2); 211 if (ret) 212 return ret; 213 *val = le16_to_cpu(bulk); 214 215 return 0; 216 } 217 218 static int ak8974_set_u16_val(struct ak8974 *ak8974, u8 reg, u16 val) 219 { 220 __le16 bulk = cpu_to_le16(val); 221 222 return regmap_bulk_write(ak8974->map, reg, &bulk, 2); 223 } 224 225 static int ak8974_set_power(struct ak8974 *ak8974, bool mode) 226 { 227 int ret; 228 u8 val; 229 230 val = mode ? AK8974_CTRL1_POWER : 0; 231 val |= AK8974_CTRL1_FORCE_EN; 232 ret = regmap_write(ak8974->map, AK8974_CTRL1, val); 233 if (ret < 0) 234 return ret; 235 236 if (mode) 237 msleep(AK8974_ACTIVATE_DELAY); 238 239 return 0; 240 } 241 242 static int ak8974_reset(struct ak8974 *ak8974) 243 { 244 int ret; 245 246 /* Power on to get register access. Sets CTRL1 reg to reset state */ 247 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 248 if (ret) 249 return ret; 250 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF); 251 if (ret) 252 return ret; 253 ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF); 254 if (ret) 255 return ret; 256 if (ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A) { 257 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, 258 AK8974_INT_CTRL_RESDEF); 259 if (ret) 260 return ret; 261 } else { 262 ret = regmap_write(ak8974->map, HSCDTD008A_CTRL4, 263 HSCDTD008A_CTRL4_RESDEF); 264 if (ret) 265 return ret; 266 } 267 268 /* After reset, power off is default state */ 269 return ak8974_set_power(ak8974, AK8974_PWR_OFF); 270 } 271 272 static int ak8974_configure(struct ak8974 *ak8974) 273 { 274 int ret; 275 276 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN | 277 AK8974_CTRL2_INT_EN); 278 if (ret) 279 return ret; 280 ret = regmap_write(ak8974->map, AK8974_CTRL3, 0); 281 if (ret) 282 return ret; 283 if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI306) { 284 /* magic from datasheet: set high-speed measurement mode */ 285 ret = ak8974_set_u16_val(ak8974, AMI306_CTRL4, 0xA07E); 286 if (ret) 287 return ret; 288 } 289 if (ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A) 290 return 0; 291 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL); 292 if (ret) 293 return ret; 294 295 return regmap_write(ak8974->map, AK8974_PRESET, 0); 296 } 297 298 static int ak8974_trigmeas(struct ak8974 *ak8974) 299 { 300 unsigned int clear; 301 u8 mask; 302 u8 val; 303 int ret; 304 305 /* Clear any previous measurement overflow status */ 306 ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear); 307 if (ret) 308 return ret; 309 310 /* If we have a DRDY IRQ line, use it */ 311 if (ak8974->drdy_irq) { 312 mask = AK8974_CTRL2_INT_EN | 313 AK8974_CTRL2_DRDY_EN | 314 AK8974_CTRL2_DRDY_POL; 315 val = AK8974_CTRL2_DRDY_EN; 316 317 if (!ak8974->drdy_active_low) 318 val |= AK8974_CTRL2_DRDY_POL; 319 320 init_completion(&ak8974->drdy_complete); 321 ret = regmap_update_bits(ak8974->map, AK8974_CTRL2, 322 mask, val); 323 if (ret) 324 return ret; 325 } 326 327 /* Force a measurement */ 328 return regmap_update_bits(ak8974->map, 329 AK8974_CTRL3, 330 AK8974_CTRL3_FORCE, 331 AK8974_CTRL3_FORCE); 332 } 333 334 static int ak8974_await_drdy(struct ak8974 *ak8974) 335 { 336 int timeout = 2; 337 unsigned int val; 338 int ret; 339 340 if (ak8974->drdy_irq) { 341 ret = wait_for_completion_timeout(&ak8974->drdy_complete, 342 1 + msecs_to_jiffies(1000)); 343 if (!ret) { 344 dev_err(&ak8974->i2c->dev, 345 "timeout waiting for DRDY IRQ\n"); 346 return -ETIMEDOUT; 347 } 348 return 0; 349 } 350 351 /* Default delay-based poll loop */ 352 do { 353 msleep(AK8974_MEASTIME); 354 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 355 if (ret < 0) 356 return ret; 357 if (val & AK8974_STATUS_DRDY) 358 return 0; 359 } while (--timeout); 360 361 dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n"); 362 return -ETIMEDOUT; 363 } 364 365 static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result) 366 { 367 unsigned int src; 368 int ret; 369 370 ret = ak8974_await_drdy(ak8974); 371 if (ret) 372 return ret; 373 ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src); 374 if (ret < 0) 375 return ret; 376 377 /* Out of range overflow! Strong magnet close? */ 378 if (src & AK8974_INT_RANGE) { 379 dev_err(&ak8974->i2c->dev, 380 "range overflow in sensor\n"); 381 return -ERANGE; 382 } 383 384 ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6); 385 if (ret) 386 return ret; 387 388 return ret; 389 } 390 391 static irqreturn_t ak8974_drdy_irq(int irq, void *d) 392 { 393 struct ak8974 *ak8974 = d; 394 395 if (!ak8974->drdy_irq) 396 return IRQ_NONE; 397 398 /* TODO: timestamp here to get good measurement stamps */ 399 return IRQ_WAKE_THREAD; 400 } 401 402 static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d) 403 { 404 struct ak8974 *ak8974 = d; 405 unsigned int val; 406 int ret; 407 408 /* Check if this was a DRDY from us */ 409 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 410 if (ret < 0) { 411 dev_err(&ak8974->i2c->dev, "error reading DRDY status\n"); 412 return IRQ_HANDLED; 413 } 414 if (val & AK8974_STATUS_DRDY) { 415 /* Yes this was our IRQ */ 416 complete(&ak8974->drdy_complete); 417 return IRQ_HANDLED; 418 } 419 420 /* We may be on a shared IRQ, let the next client check */ 421 return IRQ_NONE; 422 } 423 424 static int ak8974_selftest(struct ak8974 *ak8974) 425 { 426 struct device *dev = &ak8974->i2c->dev; 427 unsigned int val; 428 int ret; 429 430 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 431 if (ret) 432 return ret; 433 if (val != AK8974_SELFTEST_IDLE) { 434 dev_err(dev, "selftest not idle before test\n"); 435 return -EIO; 436 } 437 438 /* Trigger self-test */ 439 ret = regmap_update_bits(ak8974->map, 440 AK8974_CTRL3, 441 AK8974_CTRL3_SELFTEST, 442 AK8974_CTRL3_SELFTEST); 443 if (ret) { 444 dev_err(dev, "could not write CTRL3\n"); 445 return ret; 446 } 447 448 msleep(AK8974_SELFTEST_DELAY); 449 450 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 451 if (ret) 452 return ret; 453 if (val != AK8974_SELFTEST_OK) { 454 dev_err(dev, "selftest result NOT OK (%02x)\n", val); 455 return -EIO; 456 } 457 458 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 459 if (ret) 460 return ret; 461 if (val != AK8974_SELFTEST_IDLE) { 462 dev_err(dev, "selftest not idle after test (%02x)\n", val); 463 return -EIO; 464 } 465 dev_dbg(dev, "passed self-test\n"); 466 467 return 0; 468 } 469 470 static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg, 471 __le16 *tab, size_t tab_size) 472 { 473 int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size); 474 if (ret) { 475 memset(tab, 0xFF, tab_size); 476 dev_warn(&ak8974->i2c->dev, 477 "can't read calibration data (regs %u..%zu): %d\n", 478 reg, reg + tab_size - 1, ret); 479 } else { 480 add_device_randomness(tab, tab_size); 481 } 482 } 483 484 static int ak8974_detect(struct ak8974 *ak8974) 485 { 486 unsigned int whoami; 487 const char *name; 488 int ret; 489 unsigned int fw; 490 u16 sn; 491 492 ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami); 493 if (ret) 494 return ret; 495 496 name = "ami305"; 497 498 switch (whoami) { 499 case AK8974_WHOAMI_VALUE_AMI306: 500 name = "ami306"; 501 /* fall-through */ 502 case AK8974_WHOAMI_VALUE_AMI305: 503 ret = regmap_read(ak8974->map, AMI305_VER, &fw); 504 if (ret) 505 return ret; 506 fw &= 0x7f; /* only bits 0 thru 6 valid */ 507 ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn); 508 if (ret) 509 return ret; 510 add_device_randomness(&sn, sizeof(sn)); 511 dev_info(&ak8974->i2c->dev, 512 "detected %s, FW ver %02x, S/N: %04x\n", 513 name, fw, sn); 514 break; 515 case AK8974_WHOAMI_VALUE_AK8974: 516 name = "ak8974"; 517 dev_info(&ak8974->i2c->dev, "detected AK8974\n"); 518 break; 519 case AK8974_WHOAMI_VALUE_HSCDTD008A: 520 name = "hscdtd008a"; 521 dev_info(&ak8974->i2c->dev, "detected hscdtd008a\n"); 522 break; 523 default: 524 dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ", 525 whoami); 526 return -ENODEV; 527 } 528 529 ak8974->name = name; 530 ak8974->variant = whoami; 531 532 if (whoami == AK8974_WHOAMI_VALUE_AMI306) { 533 __le16 fab_data1[9], fab_data2[3]; 534 int i; 535 536 ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X, 537 fab_data1, sizeof(fab_data1)); 538 ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X, 539 fab_data2, sizeof(fab_data2)); 540 541 for (i = 0; i < 3; ++i) { 542 static const char axis[3] = "XYZ"; 543 static const char pgaxis[6] = "ZYZXYX"; 544 unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F; 545 unsigned fine = le16_to_cpu(fab_data1[i]); 546 unsigned sens = le16_to_cpu(fab_data1[i + 3]); 547 unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]); 548 unsigned pgain2 = pgain1 >> 8; 549 550 pgain1 &= 0xFF; 551 552 dev_info(&ak8974->i2c->dev, 553 "factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n", 554 axis[i], offz, sens, fine, pgaxis[i * 2], 555 pgain1, pgaxis[i * 2 + 1], pgain2); 556 } 557 } 558 559 return 0; 560 } 561 562 static int ak8974_measure_channel(struct ak8974 *ak8974, unsigned long address, 563 int *val) 564 { 565 __le16 hw_values[3]; 566 int ret; 567 568 pm_runtime_get_sync(&ak8974->i2c->dev); 569 mutex_lock(&ak8974->lock); 570 571 /* 572 * We read all axes and discard all but one, for optimized 573 * reading, use the triggered buffer. 574 */ 575 ret = ak8974_trigmeas(ak8974); 576 if (ret) 577 goto out_unlock; 578 ret = ak8974_getresult(ak8974, hw_values); 579 if (ret) 580 goto out_unlock; 581 /* 582 * This explicit cast to (s16) is necessary as the measurement 583 * is done in 2's complement with positive and negative values. 584 * The follwing assignment to *val will then convert the signed 585 * s16 value to a signed int value. 586 */ 587 *val = (s16)le16_to_cpu(hw_values[address]); 588 out_unlock: 589 mutex_unlock(&ak8974->lock); 590 pm_runtime_mark_last_busy(&ak8974->i2c->dev); 591 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 592 593 return ret; 594 } 595 596 static int ak8974_read_raw(struct iio_dev *indio_dev, 597 struct iio_chan_spec const *chan, 598 int *val, int *val2, 599 long mask) 600 { 601 struct ak8974 *ak8974 = iio_priv(indio_dev); 602 int ret; 603 604 switch (mask) { 605 case IIO_CHAN_INFO_RAW: 606 if (chan->address > 2) { 607 dev_err(&ak8974->i2c->dev, "faulty channel address\n"); 608 return -EIO; 609 } 610 ret = ak8974_measure_channel(ak8974, chan->address, val); 611 if (ret) 612 return ret; 613 return IIO_VAL_INT; 614 case IIO_CHAN_INFO_SCALE: 615 switch (ak8974->variant) { 616 case AK8974_WHOAMI_VALUE_AMI306: 617 case AK8974_WHOAMI_VALUE_AMI305: 618 /* 619 * The datasheet for AMI305 and AMI306, page 6 620 * specifies the range of the sensor to be 621 * +/- 12 Gauss. 622 */ 623 *val = 12; 624 /* 625 * 12 bits are used, +/- 2^11 626 * [ -2048 .. 2047 ] (manual page 20) 627 * [ 0xf800 .. 0x07ff ] 628 */ 629 *val2 = 11; 630 return IIO_VAL_FRACTIONAL_LOG2; 631 case AK8974_WHOAMI_VALUE_HSCDTD008A: 632 /* 633 * The datasheet for HSCDTF008A, page 3 specifies the 634 * range of the sensor as +/- 2.4 mT per axis, which 635 * corresponds to +/- 2400 uT = +/- 24 Gauss. 636 */ 637 *val = 24; 638 /* 639 * 15 bits are used (set up in CTRL4), +/- 2^14 640 * [ -16384 .. 16383 ] (manual page 24) 641 * [ 0xc000 .. 0x3fff ] 642 */ 643 *val2 = 14; 644 return IIO_VAL_FRACTIONAL_LOG2; 645 default: 646 /* GUESSING +/- 12 Gauss */ 647 *val = 12; 648 /* GUESSING 12 bits ADC +/- 2^11 */ 649 *val2 = 11; 650 return IIO_VAL_FRACTIONAL_LOG2; 651 } 652 break; 653 default: 654 /* Unknown request */ 655 break; 656 } 657 658 return -EINVAL; 659 } 660 661 static void ak8974_fill_buffer(struct iio_dev *indio_dev) 662 { 663 struct ak8974 *ak8974 = iio_priv(indio_dev); 664 int ret; 665 666 pm_runtime_get_sync(&ak8974->i2c->dev); 667 mutex_lock(&ak8974->lock); 668 669 ret = ak8974_trigmeas(ak8974); 670 if (ret) { 671 dev_err(&ak8974->i2c->dev, "error triggering measure\n"); 672 goto out_unlock; 673 } 674 ret = ak8974_getresult(ak8974, ak8974->scan.channels); 675 if (ret) { 676 dev_err(&ak8974->i2c->dev, "error getting measures\n"); 677 goto out_unlock; 678 } 679 680 iio_push_to_buffers_with_timestamp(indio_dev, &ak8974->scan, 681 iio_get_time_ns(indio_dev)); 682 683 out_unlock: 684 mutex_unlock(&ak8974->lock); 685 pm_runtime_mark_last_busy(&ak8974->i2c->dev); 686 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 687 } 688 689 static irqreturn_t ak8974_handle_trigger(int irq, void *p) 690 { 691 const struct iio_poll_func *pf = p; 692 struct iio_dev *indio_dev = pf->indio_dev; 693 694 ak8974_fill_buffer(indio_dev); 695 iio_trigger_notify_done(indio_dev->trig); 696 697 return IRQ_HANDLED; 698 } 699 700 static const struct iio_mount_matrix * 701 ak8974_get_mount_matrix(const struct iio_dev *indio_dev, 702 const struct iio_chan_spec *chan) 703 { 704 struct ak8974 *ak8974 = iio_priv(indio_dev); 705 706 return &ak8974->orientation; 707 } 708 709 static const struct iio_chan_spec_ext_info ak8974_ext_info[] = { 710 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix), 711 { }, 712 }; 713 714 #define AK8974_AXIS_CHANNEL(axis, index, bits) \ 715 { \ 716 .type = IIO_MAGN, \ 717 .modified = 1, \ 718 .channel2 = IIO_MOD_##axis, \ 719 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 720 BIT(IIO_CHAN_INFO_SCALE), \ 721 .ext_info = ak8974_ext_info, \ 722 .address = index, \ 723 .scan_index = index, \ 724 .scan_type = { \ 725 .sign = 's', \ 726 .realbits = bits, \ 727 .storagebits = 16, \ 728 .endianness = IIO_LE \ 729 }, \ 730 } 731 732 /* 733 * We have no datasheet for the AK8974 but we guess that its 734 * ADC is 12 bits. The AMI305 and AMI306 certainly has 12bit 735 * ADC. 736 */ 737 static const struct iio_chan_spec ak8974_12_bits_channels[] = { 738 AK8974_AXIS_CHANNEL(X, 0, 12), 739 AK8974_AXIS_CHANNEL(Y, 1, 12), 740 AK8974_AXIS_CHANNEL(Z, 2, 12), 741 IIO_CHAN_SOFT_TIMESTAMP(3), 742 }; 743 744 /* 745 * The HSCDTD008A has 15 bits resolution the way we set it up 746 * in CTRL4. 747 */ 748 static const struct iio_chan_spec ak8974_15_bits_channels[] = { 749 AK8974_AXIS_CHANNEL(X, 0, 15), 750 AK8974_AXIS_CHANNEL(Y, 1, 15), 751 AK8974_AXIS_CHANNEL(Z, 2, 15), 752 IIO_CHAN_SOFT_TIMESTAMP(3), 753 }; 754 755 static const unsigned long ak8974_scan_masks[] = { 0x7, 0 }; 756 757 static const struct iio_info ak8974_info = { 758 .read_raw = &ak8974_read_raw, 759 }; 760 761 static bool ak8974_writeable_reg(struct device *dev, unsigned int reg) 762 { 763 struct i2c_client *i2c = to_i2c_client(dev); 764 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 765 struct ak8974 *ak8974 = iio_priv(indio_dev); 766 767 switch (reg) { 768 case AK8974_CTRL1: 769 case AK8974_CTRL2: 770 case AK8974_CTRL3: 771 case AK8974_INT_CTRL: 772 case AK8974_INT_THRES: 773 case AK8974_INT_THRES + 1: 774 return true; 775 case AK8974_PRESET: 776 case AK8974_PRESET + 1: 777 return ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A; 778 case AK8974_OFFSET_X: 779 case AK8974_OFFSET_X + 1: 780 case AK8974_OFFSET_Y: 781 case AK8974_OFFSET_Y + 1: 782 case AK8974_OFFSET_Z: 783 case AK8974_OFFSET_Z + 1: 784 return ak8974->variant == AK8974_WHOAMI_VALUE_AK8974 || 785 ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A; 786 case AMI305_OFFSET_X: 787 case AMI305_OFFSET_X + 1: 788 case AMI305_OFFSET_Y: 789 case AMI305_OFFSET_Y + 1: 790 case AMI305_OFFSET_Z: 791 case AMI305_OFFSET_Z + 1: 792 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 || 793 ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; 794 case AMI306_CTRL4: 795 case AMI306_CTRL4 + 1: 796 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; 797 default: 798 return false; 799 } 800 } 801 802 static bool ak8974_precious_reg(struct device *dev, unsigned int reg) 803 { 804 return reg == AK8974_INT_CLEAR; 805 } 806 807 static const struct regmap_config ak8974_regmap_config = { 808 .reg_bits = 8, 809 .val_bits = 8, 810 .max_register = 0xff, 811 .writeable_reg = ak8974_writeable_reg, 812 .precious_reg = ak8974_precious_reg, 813 }; 814 815 static int ak8974_probe(struct i2c_client *i2c, 816 const struct i2c_device_id *id) 817 { 818 struct iio_dev *indio_dev; 819 struct ak8974 *ak8974; 820 unsigned long irq_trig; 821 int irq = i2c->irq; 822 int ret; 823 824 /* Register with IIO */ 825 indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974)); 826 if (indio_dev == NULL) 827 return -ENOMEM; 828 829 ak8974 = iio_priv(indio_dev); 830 i2c_set_clientdata(i2c, indio_dev); 831 ak8974->i2c = i2c; 832 mutex_init(&ak8974->lock); 833 834 ret = iio_read_mount_matrix(&i2c->dev, "mount-matrix", 835 &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 if (ret != -EPROBE_DEFER) 847 dev_err(&i2c->dev, "cannot get regulators: %d\n", ret); 848 else 849 dev_dbg(&i2c->dev, 850 "regulators unavailable, deferring probe\n"); 851 852 return ret; 853 } 854 855 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 856 if (ret < 0) { 857 dev_err(&i2c->dev, "cannot enable regulators\n"); 858 return ret; 859 } 860 861 /* Take runtime PM online */ 862 pm_runtime_get_noresume(&i2c->dev); 863 pm_runtime_set_active(&i2c->dev); 864 pm_runtime_enable(&i2c->dev); 865 866 ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config); 867 if (IS_ERR(ak8974->map)) { 868 dev_err(&i2c->dev, "failed to allocate register map\n"); 869 pm_runtime_put_noidle(&i2c->dev); 870 pm_runtime_disable(&i2c->dev); 871 return PTR_ERR(ak8974->map); 872 } 873 874 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 875 if (ret) { 876 dev_err(&i2c->dev, "could not power on\n"); 877 goto disable_pm; 878 } 879 880 ret = ak8974_detect(ak8974); 881 if (ret) { 882 dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n"); 883 goto disable_pm; 884 } 885 886 ret = ak8974_selftest(ak8974); 887 if (ret) 888 dev_err(&i2c->dev, "selftest failed (continuing anyway)\n"); 889 890 ret = ak8974_reset(ak8974); 891 if (ret) { 892 dev_err(&i2c->dev, "AK8974 reset failed\n"); 893 goto disable_pm; 894 } 895 896 indio_dev->dev.parent = &i2c->dev; 897 switch (ak8974->variant) { 898 case AK8974_WHOAMI_VALUE_AMI306: 899 case AK8974_WHOAMI_VALUE_AMI305: 900 indio_dev->channels = ak8974_12_bits_channels; 901 indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels); 902 break; 903 case AK8974_WHOAMI_VALUE_HSCDTD008A: 904 indio_dev->channels = ak8974_15_bits_channels; 905 indio_dev->num_channels = ARRAY_SIZE(ak8974_15_bits_channels); 906 break; 907 default: 908 indio_dev->channels = ak8974_12_bits_channels; 909 indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels); 910 break; 911 } 912 indio_dev->info = &ak8974_info; 913 indio_dev->available_scan_masks = ak8974_scan_masks; 914 indio_dev->modes = INDIO_DIRECT_MODE; 915 indio_dev->name = ak8974->name; 916 917 ret = iio_triggered_buffer_setup(indio_dev, NULL, 918 ak8974_handle_trigger, 919 NULL); 920 if (ret) { 921 dev_err(&i2c->dev, "triggered buffer setup failed\n"); 922 goto disable_pm; 923 } 924 925 /* If we have a valid DRDY IRQ, make use of it */ 926 if (irq > 0) { 927 irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq)); 928 if (irq_trig == IRQF_TRIGGER_RISING) { 929 dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n"); 930 } else if (irq_trig == IRQF_TRIGGER_FALLING) { 931 ak8974->drdy_active_low = true; 932 dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n"); 933 } else { 934 irq_trig = IRQF_TRIGGER_RISING; 935 } 936 irq_trig |= IRQF_ONESHOT; 937 irq_trig |= IRQF_SHARED; 938 939 ret = devm_request_threaded_irq(&i2c->dev, 940 irq, 941 ak8974_drdy_irq, 942 ak8974_drdy_irq_thread, 943 irq_trig, 944 ak8974->name, 945 ak8974); 946 if (ret) { 947 dev_err(&i2c->dev, "unable to request DRDY IRQ " 948 "- proceeding without IRQ\n"); 949 goto no_irq; 950 } 951 ak8974->drdy_irq = true; 952 } 953 954 no_irq: 955 ret = iio_device_register(indio_dev); 956 if (ret) { 957 dev_err(&i2c->dev, "device register failed\n"); 958 goto cleanup_buffer; 959 } 960 961 pm_runtime_set_autosuspend_delay(&i2c->dev, 962 AK8974_AUTOSUSPEND_DELAY); 963 pm_runtime_use_autosuspend(&i2c->dev); 964 pm_runtime_put(&i2c->dev); 965 966 return 0; 967 968 cleanup_buffer: 969 iio_triggered_buffer_cleanup(indio_dev); 970 disable_pm: 971 pm_runtime_put_noidle(&i2c->dev); 972 pm_runtime_disable(&i2c->dev); 973 ak8974_set_power(ak8974, AK8974_PWR_OFF); 974 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 975 976 return ret; 977 } 978 979 static int ak8974_remove(struct i2c_client *i2c) 980 { 981 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 982 struct ak8974 *ak8974 = iio_priv(indio_dev); 983 984 iio_device_unregister(indio_dev); 985 iio_triggered_buffer_cleanup(indio_dev); 986 pm_runtime_get_sync(&i2c->dev); 987 pm_runtime_put_noidle(&i2c->dev); 988 pm_runtime_disable(&i2c->dev); 989 ak8974_set_power(ak8974, AK8974_PWR_OFF); 990 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 991 992 return 0; 993 } 994 995 static int __maybe_unused ak8974_runtime_suspend(struct device *dev) 996 { 997 struct ak8974 *ak8974 = 998 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 999 1000 ak8974_set_power(ak8974, AK8974_PWR_OFF); 1001 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 1002 1003 return 0; 1004 } 1005 1006 static int __maybe_unused ak8974_runtime_resume(struct device *dev) 1007 { 1008 struct ak8974 *ak8974 = 1009 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 1010 int ret; 1011 1012 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 1013 if (ret) 1014 return ret; 1015 msleep(AK8974_POWERON_DELAY); 1016 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 1017 if (ret) 1018 goto out_regulator_disable; 1019 1020 ret = ak8974_configure(ak8974); 1021 if (ret) 1022 goto out_disable_power; 1023 1024 return 0; 1025 1026 out_disable_power: 1027 ak8974_set_power(ak8974, AK8974_PWR_OFF); 1028 out_regulator_disable: 1029 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 1030 1031 return ret; 1032 } 1033 1034 static const struct dev_pm_ops ak8974_dev_pm_ops = { 1035 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, 1036 pm_runtime_force_resume) 1037 SET_RUNTIME_PM_OPS(ak8974_runtime_suspend, 1038 ak8974_runtime_resume, NULL) 1039 }; 1040 1041 static const struct i2c_device_id ak8974_id[] = { 1042 {"ami305", 0 }, 1043 {"ami306", 0 }, 1044 {"ak8974", 0 }, 1045 {"hscdtd008a", 0 }, 1046 {} 1047 }; 1048 MODULE_DEVICE_TABLE(i2c, ak8974_id); 1049 1050 static const struct of_device_id ak8974_of_match[] = { 1051 { .compatible = "asahi-kasei,ak8974", }, 1052 { .compatible = "alps,hscdtd008a", }, 1053 {} 1054 }; 1055 MODULE_DEVICE_TABLE(of, ak8974_of_match); 1056 1057 static struct i2c_driver ak8974_driver = { 1058 .driver = { 1059 .name = "ak8974", 1060 .pm = &ak8974_dev_pm_ops, 1061 .of_match_table = of_match_ptr(ak8974_of_match), 1062 }, 1063 .probe = ak8974_probe, 1064 .remove = ak8974_remove, 1065 .id_table = ak8974_id, 1066 }; 1067 module_i2c_driver(ak8974_driver); 1068 1069 MODULE_DESCRIPTION("AK8974 and AMI30x 3-axis magnetometer driver"); 1070 MODULE_AUTHOR("Samu Onkalo"); 1071 MODULE_AUTHOR("Linus Walleij"); 1072 MODULE_LICENSE("GPL v2"); 1073