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 */ 186 struct 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 aligned_s64 ts; 201 } scan; 202 }; 203 204 static const char ak8974_reg_avdd[] = "avdd"; 205 static const char ak8974_reg_dvdd[] = "dvdd"; 206 207 static 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 } 219 220 static 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 } 226 227 static 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 } 243 244 static 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 } 273 274 static 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 } 299 300 static 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_set_bits(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_FORCE); 331 } 332 333 static int ak8974_await_drdy(struct ak8974 *ak8974) 334 { 335 int timeout = 2; 336 unsigned int val; 337 int ret; 338 339 if (ak8974->drdy_irq) { 340 ret = wait_for_completion_timeout(&ak8974->drdy_complete, 341 1 + msecs_to_jiffies(1000)); 342 if (!ret) { 343 dev_err(&ak8974->i2c->dev, 344 "timeout waiting for DRDY IRQ\n"); 345 return -ETIMEDOUT; 346 } 347 return 0; 348 } 349 350 /* Default delay-based poll loop */ 351 do { 352 msleep(AK8974_MEASTIME); 353 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 354 if (ret < 0) 355 return ret; 356 if (val & AK8974_STATUS_DRDY) 357 return 0; 358 } while (--timeout); 359 360 dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n"); 361 return -ETIMEDOUT; 362 } 363 364 static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result) 365 { 366 unsigned int src; 367 int ret; 368 369 ret = ak8974_await_drdy(ak8974); 370 if (ret) 371 return ret; 372 ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src); 373 if (ret < 0) 374 return ret; 375 376 /* Out of range overflow! Strong magnet close? */ 377 if (src & AK8974_INT_RANGE) { 378 dev_err(&ak8974->i2c->dev, 379 "range overflow in sensor\n"); 380 return -ERANGE; 381 } 382 383 ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6); 384 if (ret) 385 return ret; 386 387 return ret; 388 } 389 390 static irqreturn_t ak8974_drdy_irq(int irq, void *d) 391 { 392 struct ak8974 *ak8974 = d; 393 394 if (!ak8974->drdy_irq) 395 return IRQ_NONE; 396 397 /* TODO: timestamp here to get good measurement stamps */ 398 return IRQ_WAKE_THREAD; 399 } 400 401 static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d) 402 { 403 struct ak8974 *ak8974 = d; 404 unsigned int val; 405 int ret; 406 407 /* Check if this was a DRDY from us */ 408 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 409 if (ret < 0) { 410 dev_err(&ak8974->i2c->dev, "error reading DRDY status\n"); 411 return IRQ_HANDLED; 412 } 413 if (val & AK8974_STATUS_DRDY) { 414 /* Yes this was our IRQ */ 415 complete(&ak8974->drdy_complete); 416 return IRQ_HANDLED; 417 } 418 419 /* We may be on a shared IRQ, let the next client check */ 420 return IRQ_NONE; 421 } 422 423 static int ak8974_selftest(struct ak8974 *ak8974) 424 { 425 struct device *dev = &ak8974->i2c->dev; 426 unsigned int val; 427 int ret; 428 429 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 430 if (ret) 431 return ret; 432 if (val != AK8974_SELFTEST_IDLE) { 433 dev_err(dev, "selftest not idle before test\n"); 434 return -EIO; 435 } 436 437 /* Trigger self-test */ 438 ret = regmap_set_bits(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_SELFTEST); 439 if (ret) { 440 dev_err(dev, "could not write CTRL3\n"); 441 return ret; 442 } 443 444 msleep(AK8974_SELFTEST_DELAY); 445 446 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 447 if (ret) 448 return ret; 449 if (val != AK8974_SELFTEST_OK) { 450 dev_err(dev, "selftest result NOT OK (%02x)\n", val); 451 return -EIO; 452 } 453 454 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 455 if (ret) 456 return ret; 457 if (val != AK8974_SELFTEST_IDLE) { 458 dev_err(dev, "selftest not idle after test (%02x)\n", val); 459 return -EIO; 460 } 461 dev_dbg(dev, "passed self-test\n"); 462 463 return 0; 464 } 465 466 static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg, 467 __le16 *tab, size_t tab_size) 468 { 469 int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size); 470 if (ret) { 471 memset(tab, 0xFF, tab_size); 472 dev_warn(&ak8974->i2c->dev, 473 "can't read calibration data (regs %u..%zu): %d\n", 474 reg, reg + tab_size - 1, ret); 475 } else { 476 add_device_randomness(tab, tab_size); 477 } 478 } 479 480 static int ak8974_detect(struct ak8974 *ak8974) 481 { 482 unsigned int whoami; 483 const char *name; 484 int ret; 485 unsigned int fw; 486 u16 sn; 487 488 ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami); 489 if (ret) 490 return ret; 491 492 name = "ami305"; 493 494 switch (whoami) { 495 case AK8974_WHOAMI_VALUE_AMI306: 496 name = "ami306"; 497 fallthrough; 498 case AK8974_WHOAMI_VALUE_AMI305: 499 ret = regmap_read(ak8974->map, AMI305_VER, &fw); 500 if (ret) 501 return ret; 502 fw &= 0x7f; /* only bits 0 thru 6 valid */ 503 ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn); 504 if (ret) 505 return ret; 506 add_device_randomness(&sn, sizeof(sn)); 507 dev_info(&ak8974->i2c->dev, 508 "detected %s, FW ver %02x, S/N: %04x\n", 509 name, fw, sn); 510 break; 511 case AK8974_WHOAMI_VALUE_AK8974: 512 name = "ak8974"; 513 dev_info(&ak8974->i2c->dev, "detected AK8974\n"); 514 break; 515 case AK8974_WHOAMI_VALUE_HSCDTD008A: 516 name = "hscdtd008a"; 517 dev_info(&ak8974->i2c->dev, "detected hscdtd008a\n"); 518 break; 519 default: 520 dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ", 521 whoami); 522 return -ENODEV; 523 } 524 525 ak8974->name = name; 526 ak8974->variant = whoami; 527 528 if (whoami == AK8974_WHOAMI_VALUE_AMI306) { 529 __le16 fab_data1[9], fab_data2[3]; 530 int i; 531 532 ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X, 533 fab_data1, sizeof(fab_data1)); 534 ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X, 535 fab_data2, sizeof(fab_data2)); 536 537 for (i = 0; i < 3; ++i) { 538 static const char axis[] = "XYZ"; 539 static const char pgaxis[] = "ZYZXYX"; 540 unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F; 541 unsigned fine = le16_to_cpu(fab_data1[i]); 542 unsigned sens = le16_to_cpu(fab_data1[i + 3]); 543 unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]); 544 unsigned pgain2 = pgain1 >> 8; 545 546 pgain1 &= 0xFF; 547 548 dev_info(&ak8974->i2c->dev, 549 "factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n", 550 axis[i], offz, sens, fine, pgaxis[i * 2], 551 pgain1, pgaxis[i * 2 + 1], pgain2); 552 } 553 } 554 555 return 0; 556 } 557 558 static int ak8974_measure_channel(struct ak8974 *ak8974, unsigned long address, 559 int *val) 560 { 561 __le16 hw_values[3]; 562 int ret; 563 564 pm_runtime_get_sync(&ak8974->i2c->dev); 565 mutex_lock(&ak8974->lock); 566 567 /* 568 * We read all axes and discard all but one, for optimized 569 * reading, use the triggered buffer. 570 */ 571 ret = ak8974_trigmeas(ak8974); 572 if (ret) 573 goto out_unlock; 574 ret = ak8974_getresult(ak8974, hw_values); 575 if (ret) 576 goto out_unlock; 577 /* 578 * This explicit cast to (s16) is necessary as the measurement 579 * is done in 2's complement with positive and negative values. 580 * The follwing assignment to *val will then convert the signed 581 * s16 value to a signed int value. 582 */ 583 *val = (s16)le16_to_cpu(hw_values[address]); 584 out_unlock: 585 mutex_unlock(&ak8974->lock); 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; 660 661 pm_runtime_get_sync(&ak8974->i2c->dev); 662 mutex_lock(&ak8974->lock); 663 664 ret = ak8974_trigmeas(ak8974); 665 if (ret) { 666 dev_err(&ak8974->i2c->dev, "error triggering measure\n"); 667 goto out_unlock; 668 } 669 ret = ak8974_getresult(ak8974, ak8974->scan.channels); 670 if (ret) { 671 dev_err(&ak8974->i2c->dev, "error getting measures\n"); 672 goto out_unlock; 673 } 674 675 iio_push_to_buffers_with_ts(indio_dev, &ak8974->scan, sizeof(ak8974->scan), 676 iio_get_time_ns(indio_dev)); 677 678 out_unlock: 679 mutex_unlock(&ak8974->lock); 680 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 681 } 682 683 static irqreturn_t ak8974_handle_trigger(int irq, void *p) 684 { 685 const struct iio_poll_func *pf = p; 686 struct iio_dev *indio_dev = pf->indio_dev; 687 688 ak8974_fill_buffer(indio_dev); 689 iio_trigger_notify_done(indio_dev->trig); 690 691 return IRQ_HANDLED; 692 } 693 694 static const struct iio_mount_matrix * 695 ak8974_get_mount_matrix(const struct iio_dev *indio_dev, 696 const struct iio_chan_spec *chan) 697 { 698 struct ak8974 *ak8974 = iio_priv(indio_dev); 699 700 return &ak8974->orientation; 701 } 702 703 static const struct iio_chan_spec_ext_info ak8974_ext_info[] = { 704 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix), 705 { } 706 }; 707 708 #define AK8974_AXIS_CHANNEL(axis, index, bits) \ 709 { \ 710 .type = IIO_MAGN, \ 711 .modified = 1, \ 712 .channel2 = IIO_MOD_##axis, \ 713 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 714 BIT(IIO_CHAN_INFO_SCALE), \ 715 .ext_info = ak8974_ext_info, \ 716 .address = index, \ 717 .scan_index = index, \ 718 .scan_type = { \ 719 .sign = 's', \ 720 .realbits = bits, \ 721 .storagebits = 16, \ 722 .endianness = IIO_LE \ 723 }, \ 724 } 725 726 /* 727 * We have no datasheet for the AK8974 but we guess that its 728 * ADC is 12 bits. The AMI305 and AMI306 certainly has 12bit 729 * ADC. 730 */ 731 static const struct iio_chan_spec ak8974_12_bits_channels[] = { 732 AK8974_AXIS_CHANNEL(X, 0, 12), 733 AK8974_AXIS_CHANNEL(Y, 1, 12), 734 AK8974_AXIS_CHANNEL(Z, 2, 12), 735 IIO_CHAN_SOFT_TIMESTAMP(3), 736 }; 737 738 /* 739 * The HSCDTD008A has 15 bits resolution the way we set it up 740 * in CTRL4. 741 */ 742 static const struct iio_chan_spec ak8974_15_bits_channels[] = { 743 AK8974_AXIS_CHANNEL(X, 0, 15), 744 AK8974_AXIS_CHANNEL(Y, 1, 15), 745 AK8974_AXIS_CHANNEL(Z, 2, 15), 746 IIO_CHAN_SOFT_TIMESTAMP(3), 747 }; 748 749 static const unsigned long ak8974_scan_masks[] = { 0x7, 0 }; 750 751 static const struct iio_info ak8974_info = { 752 .read_raw = &ak8974_read_raw, 753 }; 754 755 static bool ak8974_writeable_reg(struct device *dev, unsigned int reg) 756 { 757 struct i2c_client *i2c = to_i2c_client(dev); 758 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 759 struct ak8974 *ak8974 = iio_priv(indio_dev); 760 761 switch (reg) { 762 case AK8974_CTRL1: 763 case AK8974_CTRL2: 764 case AK8974_CTRL3: 765 case AK8974_INT_CTRL: 766 case AK8974_INT_THRES: 767 case AK8974_INT_THRES + 1: 768 return true; 769 case AK8974_PRESET: 770 case AK8974_PRESET + 1: 771 return ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A; 772 case AK8974_OFFSET_X: 773 case AK8974_OFFSET_X + 1: 774 case AK8974_OFFSET_Y: 775 case AK8974_OFFSET_Y + 1: 776 case AK8974_OFFSET_Z: 777 case AK8974_OFFSET_Z + 1: 778 return ak8974->variant == AK8974_WHOAMI_VALUE_AK8974 || 779 ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A; 780 case AMI305_OFFSET_X: 781 case AMI305_OFFSET_X + 1: 782 case AMI305_OFFSET_Y: 783 case AMI305_OFFSET_Y + 1: 784 case AMI305_OFFSET_Z: 785 case AMI305_OFFSET_Z + 1: 786 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 || 787 ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; 788 case AMI306_CTRL4: 789 case AMI306_CTRL4 + 1: 790 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; 791 default: 792 return false; 793 } 794 } 795 796 static bool ak8974_precious_reg(struct device *dev, unsigned int reg) 797 { 798 return reg == AK8974_INT_CLEAR; 799 } 800 801 static const struct regmap_config ak8974_regmap_config = { 802 .reg_bits = 8, 803 .val_bits = 8, 804 .max_register = 0xff, 805 .writeable_reg = ak8974_writeable_reg, 806 .precious_reg = ak8974_precious_reg, 807 }; 808 809 static int ak8974_probe(struct i2c_client *i2c) 810 { 811 struct iio_dev *indio_dev; 812 struct ak8974 *ak8974; 813 unsigned long irq_trig; 814 int irq = i2c->irq; 815 int ret; 816 817 /* Register with IIO */ 818 indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974)); 819 if (indio_dev == NULL) 820 return -ENOMEM; 821 822 ak8974 = iio_priv(indio_dev); 823 i2c_set_clientdata(i2c, indio_dev); 824 ak8974->i2c = i2c; 825 mutex_init(&ak8974->lock); 826 827 ret = iio_read_mount_matrix(&i2c->dev, &ak8974->orientation); 828 if (ret) 829 return ret; 830 831 ak8974->regs[0].supply = ak8974_reg_avdd; 832 ak8974->regs[1].supply = ak8974_reg_dvdd; 833 834 ret = devm_regulator_bulk_get(&i2c->dev, 835 ARRAY_SIZE(ak8974->regs), 836 ak8974->regs); 837 if (ret < 0) 838 return dev_err_probe(&i2c->dev, ret, "cannot get regulators\n"); 839 840 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 841 if (ret < 0) { 842 dev_err(&i2c->dev, "cannot enable regulators\n"); 843 return ret; 844 } 845 846 /* Take runtime PM online */ 847 pm_runtime_get_noresume(&i2c->dev); 848 pm_runtime_set_active(&i2c->dev); 849 pm_runtime_enable(&i2c->dev); 850 851 ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config); 852 if (IS_ERR(ak8974->map)) { 853 dev_err(&i2c->dev, "failed to allocate register map\n"); 854 pm_runtime_put_noidle(&i2c->dev); 855 pm_runtime_disable(&i2c->dev); 856 return PTR_ERR(ak8974->map); 857 } 858 859 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 860 if (ret) { 861 dev_err(&i2c->dev, "could not power on\n"); 862 goto disable_pm; 863 } 864 865 ret = ak8974_detect(ak8974); 866 if (ret) { 867 dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n"); 868 goto disable_pm; 869 } 870 871 ret = ak8974_selftest(ak8974); 872 if (ret) 873 dev_err(&i2c->dev, "selftest failed (continuing anyway)\n"); 874 875 ret = ak8974_reset(ak8974); 876 if (ret) { 877 dev_err(&i2c->dev, "AK8974 reset failed\n"); 878 goto disable_pm; 879 } 880 881 switch (ak8974->variant) { 882 case AK8974_WHOAMI_VALUE_AMI306: 883 case AK8974_WHOAMI_VALUE_AMI305: 884 indio_dev->channels = ak8974_12_bits_channels; 885 indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels); 886 break; 887 case AK8974_WHOAMI_VALUE_HSCDTD008A: 888 indio_dev->channels = ak8974_15_bits_channels; 889 indio_dev->num_channels = ARRAY_SIZE(ak8974_15_bits_channels); 890 break; 891 default: 892 indio_dev->channels = ak8974_12_bits_channels; 893 indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels); 894 break; 895 } 896 indio_dev->info = &ak8974_info; 897 indio_dev->available_scan_masks = ak8974_scan_masks; 898 indio_dev->modes = INDIO_DIRECT_MODE; 899 indio_dev->name = ak8974->name; 900 901 ret = iio_triggered_buffer_setup(indio_dev, NULL, 902 ak8974_handle_trigger, 903 NULL); 904 if (ret) { 905 dev_err(&i2c->dev, "triggered buffer setup failed\n"); 906 goto disable_pm; 907 } 908 909 /* If we have a valid DRDY IRQ, make use of it */ 910 if (irq > 0) { 911 irq_trig = irq_get_trigger_type(irq); 912 if (irq_trig == IRQF_TRIGGER_RISING) { 913 dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n"); 914 } else if (irq_trig == IRQF_TRIGGER_FALLING) { 915 ak8974->drdy_active_low = true; 916 dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n"); 917 } else { 918 irq_trig = IRQF_TRIGGER_RISING; 919 } 920 irq_trig |= IRQF_ONESHOT; 921 irq_trig |= IRQF_SHARED; 922 923 ret = devm_request_threaded_irq(&i2c->dev, 924 irq, 925 ak8974_drdy_irq, 926 ak8974_drdy_irq_thread, 927 irq_trig, 928 ak8974->name, 929 ak8974); 930 if (ret) { 931 dev_err(&i2c->dev, "unable to request DRDY IRQ " 932 "- proceeding without IRQ\n"); 933 goto no_irq; 934 } 935 ak8974->drdy_irq = true; 936 } 937 938 no_irq: 939 ret = iio_device_register(indio_dev); 940 if (ret) { 941 dev_err(&i2c->dev, "device register failed\n"); 942 goto cleanup_buffer; 943 } 944 945 pm_runtime_set_autosuspend_delay(&i2c->dev, 946 AK8974_AUTOSUSPEND_DELAY); 947 pm_runtime_use_autosuspend(&i2c->dev); 948 pm_runtime_put(&i2c->dev); 949 950 return 0; 951 952 cleanup_buffer: 953 iio_triggered_buffer_cleanup(indio_dev); 954 disable_pm: 955 pm_runtime_put_noidle(&i2c->dev); 956 pm_runtime_disable(&i2c->dev); 957 ak8974_set_power(ak8974, AK8974_PWR_OFF); 958 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 959 960 return ret; 961 } 962 963 static void ak8974_remove(struct i2c_client *i2c) 964 { 965 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 966 struct ak8974 *ak8974 = iio_priv(indio_dev); 967 968 iio_device_unregister(indio_dev); 969 iio_triggered_buffer_cleanup(indio_dev); 970 pm_runtime_get_sync(&i2c->dev); 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 } 976 977 static int ak8974_runtime_suspend(struct device *dev) 978 { 979 struct ak8974 *ak8974 = 980 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 981 982 ak8974_set_power(ak8974, AK8974_PWR_OFF); 983 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 984 985 return 0; 986 } 987 988 static int ak8974_runtime_resume(struct device *dev) 989 { 990 struct ak8974 *ak8974 = 991 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 992 int ret; 993 994 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 995 if (ret) 996 return ret; 997 msleep(AK8974_POWERON_DELAY); 998 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 999 if (ret) 1000 goto out_regulator_disable; 1001 1002 ret = ak8974_configure(ak8974); 1003 if (ret) 1004 goto out_disable_power; 1005 1006 return 0; 1007 1008 out_disable_power: 1009 ak8974_set_power(ak8974, AK8974_PWR_OFF); 1010 out_regulator_disable: 1011 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 1012 1013 return ret; 1014 } 1015 1016 static DEFINE_RUNTIME_DEV_PM_OPS(ak8974_dev_pm_ops, ak8974_runtime_suspend, 1017 ak8974_runtime_resume, NULL); 1018 1019 static const struct i2c_device_id ak8974_id[] = { 1020 { "ami305" }, 1021 { "ami306" }, 1022 { "ak8974" }, 1023 { "hscdtd008a" }, 1024 { } 1025 }; 1026 MODULE_DEVICE_TABLE(i2c, ak8974_id); 1027 1028 static const struct of_device_id ak8974_of_match[] = { 1029 { .compatible = "asahi-kasei,ak8974", }, 1030 { .compatible = "alps,hscdtd008a", }, 1031 { } 1032 }; 1033 MODULE_DEVICE_TABLE(of, ak8974_of_match); 1034 1035 static struct i2c_driver ak8974_driver = { 1036 .driver = { 1037 .name = "ak8974", 1038 .pm = pm_ptr(&ak8974_dev_pm_ops), 1039 .of_match_table = ak8974_of_match, 1040 }, 1041 .probe = ak8974_probe, 1042 .remove = ak8974_remove, 1043 .id_table = ak8974_id, 1044 }; 1045 module_i2c_driver(ak8974_driver); 1046 1047 MODULE_DESCRIPTION("AK8974 and AMI30x 3-axis magnetometer driver"); 1048 MODULE_AUTHOR("Samu Onkalo"); 1049 MODULE_AUTHOR("Linus Walleij"); 1050 MODULE_LICENSE("GPL v2"); 1051