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 * @scan: timestamps 184 */ 185 struct ak8974 { 186 struct i2c_client *i2c; 187 struct iio_mount_matrix orientation; 188 struct regmap *map; 189 struct regulator_bulk_data regs[2]; 190 const char *name; 191 u8 variant; 192 struct mutex lock; 193 bool drdy_irq; 194 struct completion drdy_complete; 195 bool drdy_active_low; 196 /* Ensure timestamp is naturally aligned */ 197 struct { 198 __le16 channels[3]; 199 s64 ts __aligned(8); 200 } scan; 201 }; 202 203 static const char ak8974_reg_avdd[] = "avdd"; 204 static const char ak8974_reg_dvdd[] = "dvdd"; 205 206 static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val) 207 { 208 int ret; 209 __le16 bulk; 210 211 ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2); 212 if (ret) 213 return ret; 214 *val = le16_to_cpu(bulk); 215 216 return 0; 217 } 218 219 static int ak8974_set_u16_val(struct ak8974 *ak8974, u8 reg, u16 val) 220 { 221 __le16 bulk = cpu_to_le16(val); 222 223 return regmap_bulk_write(ak8974->map, reg, &bulk, 2); 224 } 225 226 static int ak8974_set_power(struct ak8974 *ak8974, bool mode) 227 { 228 int ret; 229 u8 val; 230 231 val = mode ? AK8974_CTRL1_POWER : 0; 232 val |= AK8974_CTRL1_FORCE_EN; 233 ret = regmap_write(ak8974->map, AK8974_CTRL1, val); 234 if (ret < 0) 235 return ret; 236 237 if (mode) 238 msleep(AK8974_ACTIVATE_DELAY); 239 240 return 0; 241 } 242 243 static int ak8974_reset(struct ak8974 *ak8974) 244 { 245 int ret; 246 247 /* Power on to get register access. Sets CTRL1 reg to reset state */ 248 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 249 if (ret) 250 return ret; 251 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF); 252 if (ret) 253 return ret; 254 ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF); 255 if (ret) 256 return ret; 257 if (ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A) { 258 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, 259 AK8974_INT_CTRL_RESDEF); 260 if (ret) 261 return ret; 262 } else { 263 ret = regmap_write(ak8974->map, HSCDTD008A_CTRL4, 264 HSCDTD008A_CTRL4_RESDEF); 265 if (ret) 266 return ret; 267 } 268 269 /* After reset, power off is default state */ 270 return ak8974_set_power(ak8974, AK8974_PWR_OFF); 271 } 272 273 static int ak8974_configure(struct ak8974 *ak8974) 274 { 275 int ret; 276 277 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN | 278 AK8974_CTRL2_INT_EN); 279 if (ret) 280 return ret; 281 ret = regmap_write(ak8974->map, AK8974_CTRL3, 0); 282 if (ret) 283 return ret; 284 if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI306) { 285 /* magic from datasheet: set high-speed measurement mode */ 286 ret = ak8974_set_u16_val(ak8974, AMI306_CTRL4, 0xA07E); 287 if (ret) 288 return ret; 289 } 290 if (ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A) 291 return 0; 292 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL); 293 if (ret) 294 return ret; 295 296 return regmap_write(ak8974->map, AK8974_PRESET, 0); 297 } 298 299 static int ak8974_trigmeas(struct ak8974 *ak8974) 300 { 301 unsigned int clear; 302 u8 mask; 303 u8 val; 304 int ret; 305 306 /* Clear any previous measurement overflow status */ 307 ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear); 308 if (ret) 309 return ret; 310 311 /* If we have a DRDY IRQ line, use it */ 312 if (ak8974->drdy_irq) { 313 mask = AK8974_CTRL2_INT_EN | 314 AK8974_CTRL2_DRDY_EN | 315 AK8974_CTRL2_DRDY_POL; 316 val = AK8974_CTRL2_DRDY_EN; 317 318 if (!ak8974->drdy_active_low) 319 val |= AK8974_CTRL2_DRDY_POL; 320 321 init_completion(&ak8974->drdy_complete); 322 ret = regmap_update_bits(ak8974->map, AK8974_CTRL2, 323 mask, val); 324 if (ret) 325 return ret; 326 } 327 328 /* Force a measurement */ 329 return regmap_update_bits(ak8974->map, 330 AK8974_CTRL3, 331 AK8974_CTRL3_FORCE, 332 AK8974_CTRL3_FORCE); 333 } 334 335 static int ak8974_await_drdy(struct ak8974 *ak8974) 336 { 337 int timeout = 2; 338 unsigned int val; 339 int ret; 340 341 if (ak8974->drdy_irq) { 342 ret = wait_for_completion_timeout(&ak8974->drdy_complete, 343 1 + msecs_to_jiffies(1000)); 344 if (!ret) { 345 dev_err(&ak8974->i2c->dev, 346 "timeout waiting for DRDY IRQ\n"); 347 return -ETIMEDOUT; 348 } 349 return 0; 350 } 351 352 /* Default delay-based poll loop */ 353 do { 354 msleep(AK8974_MEASTIME); 355 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 356 if (ret < 0) 357 return ret; 358 if (val & AK8974_STATUS_DRDY) 359 return 0; 360 } while (--timeout); 361 362 dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n"); 363 return -ETIMEDOUT; 364 } 365 366 static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result) 367 { 368 unsigned int src; 369 int ret; 370 371 ret = ak8974_await_drdy(ak8974); 372 if (ret) 373 return ret; 374 ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src); 375 if (ret < 0) 376 return ret; 377 378 /* Out of range overflow! Strong magnet close? */ 379 if (src & AK8974_INT_RANGE) { 380 dev_err(&ak8974->i2c->dev, 381 "range overflow in sensor\n"); 382 return -ERANGE; 383 } 384 385 ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6); 386 if (ret) 387 return ret; 388 389 return ret; 390 } 391 392 static irqreturn_t ak8974_drdy_irq(int irq, void *d) 393 { 394 struct ak8974 *ak8974 = d; 395 396 if (!ak8974->drdy_irq) 397 return IRQ_NONE; 398 399 /* TODO: timestamp here to get good measurement stamps */ 400 return IRQ_WAKE_THREAD; 401 } 402 403 static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d) 404 { 405 struct ak8974 *ak8974 = d; 406 unsigned int val; 407 int ret; 408 409 /* Check if this was a DRDY from us */ 410 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 411 if (ret < 0) { 412 dev_err(&ak8974->i2c->dev, "error reading DRDY status\n"); 413 return IRQ_HANDLED; 414 } 415 if (val & AK8974_STATUS_DRDY) { 416 /* Yes this was our IRQ */ 417 complete(&ak8974->drdy_complete); 418 return IRQ_HANDLED; 419 } 420 421 /* We may be on a shared IRQ, let the next client check */ 422 return IRQ_NONE; 423 } 424 425 static int ak8974_selftest(struct ak8974 *ak8974) 426 { 427 struct device *dev = &ak8974->i2c->dev; 428 unsigned int val; 429 int ret; 430 431 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 432 if (ret) 433 return ret; 434 if (val != AK8974_SELFTEST_IDLE) { 435 dev_err(dev, "selftest not idle before test\n"); 436 return -EIO; 437 } 438 439 /* Trigger self-test */ 440 ret = regmap_update_bits(ak8974->map, 441 AK8974_CTRL3, 442 AK8974_CTRL3_SELFTEST, 443 AK8974_CTRL3_SELFTEST); 444 if (ret) { 445 dev_err(dev, "could not write CTRL3\n"); 446 return ret; 447 } 448 449 msleep(AK8974_SELFTEST_DELAY); 450 451 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 452 if (ret) 453 return ret; 454 if (val != AK8974_SELFTEST_OK) { 455 dev_err(dev, "selftest result NOT OK (%02x)\n", val); 456 return -EIO; 457 } 458 459 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 460 if (ret) 461 return ret; 462 if (val != AK8974_SELFTEST_IDLE) { 463 dev_err(dev, "selftest not idle after test (%02x)\n", val); 464 return -EIO; 465 } 466 dev_dbg(dev, "passed self-test\n"); 467 468 return 0; 469 } 470 471 static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg, 472 __le16 *tab, size_t tab_size) 473 { 474 int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size); 475 if (ret) { 476 memset(tab, 0xFF, tab_size); 477 dev_warn(&ak8974->i2c->dev, 478 "can't read calibration data (regs %u..%zu): %d\n", 479 reg, reg + tab_size - 1, ret); 480 } else { 481 add_device_randomness(tab, tab_size); 482 } 483 } 484 485 static int ak8974_detect(struct ak8974 *ak8974) 486 { 487 unsigned int whoami; 488 const char *name; 489 int ret; 490 unsigned int fw; 491 u16 sn; 492 493 ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami); 494 if (ret) 495 return ret; 496 497 name = "ami305"; 498 499 switch (whoami) { 500 case AK8974_WHOAMI_VALUE_AMI306: 501 name = "ami306"; 502 /* fall-through */ 503 case AK8974_WHOAMI_VALUE_AMI305: 504 ret = regmap_read(ak8974->map, AMI305_VER, &fw); 505 if (ret) 506 return ret; 507 fw &= 0x7f; /* only bits 0 thru 6 valid */ 508 ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn); 509 if (ret) 510 return ret; 511 add_device_randomness(&sn, sizeof(sn)); 512 dev_info(&ak8974->i2c->dev, 513 "detected %s, FW ver %02x, S/N: %04x\n", 514 name, fw, sn); 515 break; 516 case AK8974_WHOAMI_VALUE_AK8974: 517 name = "ak8974"; 518 dev_info(&ak8974->i2c->dev, "detected AK8974\n"); 519 break; 520 case AK8974_WHOAMI_VALUE_HSCDTD008A: 521 name = "hscdtd008a"; 522 dev_info(&ak8974->i2c->dev, "detected hscdtd008a\n"); 523 break; 524 default: 525 dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ", 526 whoami); 527 return -ENODEV; 528 } 529 530 ak8974->name = name; 531 ak8974->variant = whoami; 532 533 if (whoami == AK8974_WHOAMI_VALUE_AMI306) { 534 __le16 fab_data1[9], fab_data2[3]; 535 int i; 536 537 ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X, 538 fab_data1, sizeof(fab_data1)); 539 ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X, 540 fab_data2, sizeof(fab_data2)); 541 542 for (i = 0; i < 3; ++i) { 543 static const char axis[3] = "XYZ"; 544 static const char pgaxis[6] = "ZYZXYX"; 545 unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F; 546 unsigned fine = le16_to_cpu(fab_data1[i]); 547 unsigned sens = le16_to_cpu(fab_data1[i + 3]); 548 unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]); 549 unsigned pgain2 = pgain1 >> 8; 550 551 pgain1 &= 0xFF; 552 553 dev_info(&ak8974->i2c->dev, 554 "factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n", 555 axis[i], offz, sens, fine, pgaxis[i * 2], 556 pgain1, pgaxis[i * 2 + 1], pgain2); 557 } 558 } 559 560 return 0; 561 } 562 563 static int ak8974_measure_channel(struct ak8974 *ak8974, unsigned long address, 564 int *val) 565 { 566 __le16 hw_values[3]; 567 int ret; 568 569 pm_runtime_get_sync(&ak8974->i2c->dev); 570 mutex_lock(&ak8974->lock); 571 572 /* 573 * We read all axes and discard all but one, for optimized 574 * reading, use the triggered buffer. 575 */ 576 ret = ak8974_trigmeas(ak8974); 577 if (ret) 578 goto out_unlock; 579 ret = ak8974_getresult(ak8974, hw_values); 580 if (ret) 581 goto out_unlock; 582 /* 583 * This explicit cast to (s16) is necessary as the measurement 584 * is done in 2's complement with positive and negative values. 585 * The follwing assignment to *val will then convert the signed 586 * s16 value to a signed int value. 587 */ 588 *val = (s16)le16_to_cpu(hw_values[address]); 589 out_unlock: 590 mutex_unlock(&ak8974->lock); 591 pm_runtime_mark_last_busy(&ak8974->i2c->dev); 592 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 593 594 return ret; 595 } 596 597 static int ak8974_read_raw(struct iio_dev *indio_dev, 598 struct iio_chan_spec const *chan, 599 int *val, int *val2, 600 long mask) 601 { 602 struct ak8974 *ak8974 = iio_priv(indio_dev); 603 int ret; 604 605 switch (mask) { 606 case IIO_CHAN_INFO_RAW: 607 if (chan->address > 2) { 608 dev_err(&ak8974->i2c->dev, "faulty channel address\n"); 609 return -EIO; 610 } 611 ret = ak8974_measure_channel(ak8974, chan->address, val); 612 if (ret) 613 return ret; 614 return IIO_VAL_INT; 615 case IIO_CHAN_INFO_SCALE: 616 switch (ak8974->variant) { 617 case AK8974_WHOAMI_VALUE_AMI306: 618 case AK8974_WHOAMI_VALUE_AMI305: 619 /* 620 * The datasheet for AMI305 and AMI306, page 6 621 * specifies the range of the sensor to be 622 * +/- 12 Gauss. 623 */ 624 *val = 12; 625 /* 626 * 12 bits are used, +/- 2^11 627 * [ -2048 .. 2047 ] (manual page 20) 628 * [ 0xf800 .. 0x07ff ] 629 */ 630 *val2 = 11; 631 return IIO_VAL_FRACTIONAL_LOG2; 632 case AK8974_WHOAMI_VALUE_HSCDTD008A: 633 /* 634 * The datasheet for HSCDTF008A, page 3 specifies the 635 * range of the sensor as +/- 2.4 mT per axis, which 636 * corresponds to +/- 2400 uT = +/- 24 Gauss. 637 */ 638 *val = 24; 639 /* 640 * 15 bits are used (set up in CTRL4), +/- 2^14 641 * [ -16384 .. 16383 ] (manual page 24) 642 * [ 0xc000 .. 0x3fff ] 643 */ 644 *val2 = 14; 645 return IIO_VAL_FRACTIONAL_LOG2; 646 default: 647 /* GUESSING +/- 12 Gauss */ 648 *val = 12; 649 /* GUESSING 12 bits ADC +/- 2^11 */ 650 *val2 = 11; 651 return IIO_VAL_FRACTIONAL_LOG2; 652 } 653 break; 654 default: 655 /* Unknown request */ 656 break; 657 } 658 659 return -EINVAL; 660 } 661 662 static void ak8974_fill_buffer(struct iio_dev *indio_dev) 663 { 664 struct ak8974 *ak8974 = iio_priv(indio_dev); 665 int ret; 666 667 pm_runtime_get_sync(&ak8974->i2c->dev); 668 mutex_lock(&ak8974->lock); 669 670 ret = ak8974_trigmeas(ak8974); 671 if (ret) { 672 dev_err(&ak8974->i2c->dev, "error triggering measure\n"); 673 goto out_unlock; 674 } 675 ret = ak8974_getresult(ak8974, ak8974->scan.channels); 676 if (ret) { 677 dev_err(&ak8974->i2c->dev, "error getting measures\n"); 678 goto out_unlock; 679 } 680 681 iio_push_to_buffers_with_timestamp(indio_dev, &ak8974->scan, 682 iio_get_time_ns(indio_dev)); 683 684 out_unlock: 685 mutex_unlock(&ak8974->lock); 686 pm_runtime_mark_last_busy(&ak8974->i2c->dev); 687 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 688 } 689 690 static irqreturn_t ak8974_handle_trigger(int irq, void *p) 691 { 692 const struct iio_poll_func *pf = p; 693 struct iio_dev *indio_dev = pf->indio_dev; 694 695 ak8974_fill_buffer(indio_dev); 696 iio_trigger_notify_done(indio_dev->trig); 697 698 return IRQ_HANDLED; 699 } 700 701 static const struct iio_mount_matrix * 702 ak8974_get_mount_matrix(const struct iio_dev *indio_dev, 703 const struct iio_chan_spec *chan) 704 { 705 struct ak8974 *ak8974 = iio_priv(indio_dev); 706 707 return &ak8974->orientation; 708 } 709 710 static const struct iio_chan_spec_ext_info ak8974_ext_info[] = { 711 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix), 712 { }, 713 }; 714 715 #define AK8974_AXIS_CHANNEL(axis, index, bits) \ 716 { \ 717 .type = IIO_MAGN, \ 718 .modified = 1, \ 719 .channel2 = IIO_MOD_##axis, \ 720 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 721 BIT(IIO_CHAN_INFO_SCALE), \ 722 .ext_info = ak8974_ext_info, \ 723 .address = index, \ 724 .scan_index = index, \ 725 .scan_type = { \ 726 .sign = 's', \ 727 .realbits = bits, \ 728 .storagebits = 16, \ 729 .endianness = IIO_LE \ 730 }, \ 731 } 732 733 /* 734 * We have no datasheet for the AK8974 but we guess that its 735 * ADC is 12 bits. The AMI305 and AMI306 certainly has 12bit 736 * ADC. 737 */ 738 static const struct iio_chan_spec ak8974_12_bits_channels[] = { 739 AK8974_AXIS_CHANNEL(X, 0, 12), 740 AK8974_AXIS_CHANNEL(Y, 1, 12), 741 AK8974_AXIS_CHANNEL(Z, 2, 12), 742 IIO_CHAN_SOFT_TIMESTAMP(3), 743 }; 744 745 /* 746 * The HSCDTD008A has 15 bits resolution the way we set it up 747 * in CTRL4. 748 */ 749 static const struct iio_chan_spec ak8974_15_bits_channels[] = { 750 AK8974_AXIS_CHANNEL(X, 0, 15), 751 AK8974_AXIS_CHANNEL(Y, 1, 15), 752 AK8974_AXIS_CHANNEL(Z, 2, 15), 753 IIO_CHAN_SOFT_TIMESTAMP(3), 754 }; 755 756 static const unsigned long ak8974_scan_masks[] = { 0x7, 0 }; 757 758 static const struct iio_info ak8974_info = { 759 .read_raw = &ak8974_read_raw, 760 }; 761 762 static bool ak8974_writeable_reg(struct device *dev, unsigned int reg) 763 { 764 struct i2c_client *i2c = to_i2c_client(dev); 765 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 766 struct ak8974 *ak8974 = iio_priv(indio_dev); 767 768 switch (reg) { 769 case AK8974_CTRL1: 770 case AK8974_CTRL2: 771 case AK8974_CTRL3: 772 case AK8974_INT_CTRL: 773 case AK8974_INT_THRES: 774 case AK8974_INT_THRES + 1: 775 return true; 776 case AK8974_PRESET: 777 case AK8974_PRESET + 1: 778 return ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A; 779 case AK8974_OFFSET_X: 780 case AK8974_OFFSET_X + 1: 781 case AK8974_OFFSET_Y: 782 case AK8974_OFFSET_Y + 1: 783 case AK8974_OFFSET_Z: 784 case AK8974_OFFSET_Z + 1: 785 return ak8974->variant == AK8974_WHOAMI_VALUE_AK8974 || 786 ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A; 787 case AMI305_OFFSET_X: 788 case AMI305_OFFSET_X + 1: 789 case AMI305_OFFSET_Y: 790 case AMI305_OFFSET_Y + 1: 791 case AMI305_OFFSET_Z: 792 case AMI305_OFFSET_Z + 1: 793 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 || 794 ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; 795 case AMI306_CTRL4: 796 case AMI306_CTRL4 + 1: 797 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; 798 default: 799 return false; 800 } 801 } 802 803 static bool ak8974_precious_reg(struct device *dev, unsigned int reg) 804 { 805 return reg == AK8974_INT_CLEAR; 806 } 807 808 static const struct regmap_config ak8974_regmap_config = { 809 .reg_bits = 8, 810 .val_bits = 8, 811 .max_register = 0xff, 812 .writeable_reg = ak8974_writeable_reg, 813 .precious_reg = ak8974_precious_reg, 814 }; 815 816 static int ak8974_probe(struct i2c_client *i2c, 817 const struct i2c_device_id *id) 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, "mount-matrix", 836 &ak8974->orientation); 837 if (ret) 838 return ret; 839 840 ak8974->regs[0].supply = ak8974_reg_avdd; 841 ak8974->regs[1].supply = ak8974_reg_dvdd; 842 843 ret = devm_regulator_bulk_get(&i2c->dev, 844 ARRAY_SIZE(ak8974->regs), 845 ak8974->regs); 846 if (ret < 0) { 847 if (ret != -EPROBE_DEFER) 848 dev_err(&i2c->dev, "cannot get regulators: %d\n", ret); 849 else 850 dev_dbg(&i2c->dev, 851 "regulators unavailable, deferring probe\n"); 852 853 return ret; 854 } 855 856 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 857 if (ret < 0) { 858 dev_err(&i2c->dev, "cannot enable regulators\n"); 859 return ret; 860 } 861 862 /* Take runtime PM online */ 863 pm_runtime_get_noresume(&i2c->dev); 864 pm_runtime_set_active(&i2c->dev); 865 pm_runtime_enable(&i2c->dev); 866 867 ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config); 868 if (IS_ERR(ak8974->map)) { 869 dev_err(&i2c->dev, "failed to allocate register map\n"); 870 pm_runtime_put_noidle(&i2c->dev); 871 pm_runtime_disable(&i2c->dev); 872 return PTR_ERR(ak8974->map); 873 } 874 875 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 876 if (ret) { 877 dev_err(&i2c->dev, "could not power on\n"); 878 goto disable_pm; 879 } 880 881 ret = ak8974_detect(ak8974); 882 if (ret) { 883 dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n"); 884 goto disable_pm; 885 } 886 887 ret = ak8974_selftest(ak8974); 888 if (ret) 889 dev_err(&i2c->dev, "selftest failed (continuing anyway)\n"); 890 891 ret = ak8974_reset(ak8974); 892 if (ret) { 893 dev_err(&i2c->dev, "AK8974 reset failed\n"); 894 goto disable_pm; 895 } 896 897 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