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 aligned_s64 ts; 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_set_bits(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_FORCE); 330 } 331 332 static int ak8974_await_drdy(struct ak8974 *ak8974) 333 { 334 int timeout = 2; 335 unsigned int val; 336 int ret; 337 338 if (ak8974->drdy_irq) { 339 ret = wait_for_completion_timeout(&ak8974->drdy_complete, 340 1 + msecs_to_jiffies(1000)); 341 if (!ret) { 342 dev_err(&ak8974->i2c->dev, 343 "timeout waiting for DRDY IRQ\n"); 344 return -ETIMEDOUT; 345 } 346 return 0; 347 } 348 349 /* Default delay-based poll loop */ 350 do { 351 msleep(AK8974_MEASTIME); 352 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 353 if (ret < 0) 354 return ret; 355 if (val & AK8974_STATUS_DRDY) 356 return 0; 357 } while (--timeout); 358 359 dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n"); 360 return -ETIMEDOUT; 361 } 362 363 static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result) 364 { 365 unsigned int src; 366 int ret; 367 368 ret = ak8974_await_drdy(ak8974); 369 if (ret) 370 return ret; 371 ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src); 372 if (ret < 0) 373 return ret; 374 375 /* Out of range overflow! Strong magnet close? */ 376 if (src & AK8974_INT_RANGE) { 377 dev_err(&ak8974->i2c->dev, 378 "range overflow in sensor\n"); 379 return -ERANGE; 380 } 381 382 return regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6); 383 } 384 385 static irqreturn_t ak8974_drdy_irq(int irq, void *d) 386 { 387 struct ak8974 *ak8974 = d; 388 389 if (!ak8974->drdy_irq) 390 return IRQ_NONE; 391 392 /* TODO: timestamp here to get good measurement stamps */ 393 return IRQ_WAKE_THREAD; 394 } 395 396 static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d) 397 { 398 struct ak8974 *ak8974 = d; 399 unsigned int val; 400 int ret; 401 402 /* Check if this was a DRDY from us */ 403 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 404 if (ret < 0) { 405 dev_err(&ak8974->i2c->dev, "error reading DRDY status\n"); 406 return IRQ_HANDLED; 407 } 408 if (val & AK8974_STATUS_DRDY) { 409 /* Yes this was our IRQ */ 410 complete(&ak8974->drdy_complete); 411 return IRQ_HANDLED; 412 } 413 414 /* We may be on a shared IRQ, let the next client check */ 415 return IRQ_NONE; 416 } 417 418 static int ak8974_selftest(struct ak8974 *ak8974) 419 { 420 struct device *dev = &ak8974->i2c->dev; 421 unsigned int val; 422 int ret; 423 424 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 425 if (ret) 426 return ret; 427 if (val != AK8974_SELFTEST_IDLE) { 428 dev_err(dev, "selftest not idle before test\n"); 429 return -EIO; 430 } 431 432 /* Trigger self-test */ 433 ret = regmap_set_bits(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_SELFTEST); 434 if (ret) { 435 dev_err(dev, "could not write CTRL3\n"); 436 return ret; 437 } 438 439 msleep(AK8974_SELFTEST_DELAY); 440 441 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 442 if (ret) 443 return ret; 444 if (val != AK8974_SELFTEST_OK) { 445 dev_err(dev, "selftest result NOT OK (%02x)\n", val); 446 return -EIO; 447 } 448 449 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 450 if (ret) 451 return ret; 452 if (val != AK8974_SELFTEST_IDLE) { 453 dev_err(dev, "selftest not idle after test (%02x)\n", val); 454 return -EIO; 455 } 456 dev_dbg(dev, "passed self-test\n"); 457 458 return 0; 459 } 460 461 static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg, 462 __le16 *tab, size_t tab_size) 463 { 464 int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size); 465 if (ret) { 466 memset(tab, 0xFF, tab_size); 467 dev_warn(&ak8974->i2c->dev, 468 "can't read calibration data (regs %u..%zu): %d\n", 469 reg, reg + tab_size - 1, ret); 470 } else { 471 add_device_randomness(tab, tab_size); 472 } 473 } 474 475 static int ak8974_detect(struct ak8974 *ak8974) 476 { 477 unsigned int whoami; 478 const char *name; 479 int ret; 480 unsigned int fw; 481 u16 sn; 482 483 ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami); 484 if (ret) 485 return ret; 486 487 name = "ami305"; 488 489 switch (whoami) { 490 case AK8974_WHOAMI_VALUE_AMI306: 491 name = "ami306"; 492 fallthrough; 493 case AK8974_WHOAMI_VALUE_AMI305: 494 ret = regmap_read(ak8974->map, AMI305_VER, &fw); 495 if (ret) 496 return ret; 497 fw &= 0x7f; /* only bits 0 thru 6 valid */ 498 ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn); 499 if (ret) 500 return ret; 501 add_device_randomness(&sn, sizeof(sn)); 502 dev_info(&ak8974->i2c->dev, 503 "detected %s, FW ver %02x, S/N: %04x\n", 504 name, fw, sn); 505 break; 506 case AK8974_WHOAMI_VALUE_AK8974: 507 name = "ak8974"; 508 dev_info(&ak8974->i2c->dev, "detected AK8974\n"); 509 break; 510 case AK8974_WHOAMI_VALUE_HSCDTD008A: 511 name = "hscdtd008a"; 512 dev_info(&ak8974->i2c->dev, "detected hscdtd008a\n"); 513 break; 514 default: 515 dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ", 516 whoami); 517 return -ENODEV; 518 } 519 520 ak8974->name = name; 521 ak8974->variant = whoami; 522 523 if (whoami == AK8974_WHOAMI_VALUE_AMI306) { 524 __le16 fab_data1[9], fab_data2[3]; 525 int i; 526 527 ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X, 528 fab_data1, sizeof(fab_data1)); 529 ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X, 530 fab_data2, sizeof(fab_data2)); 531 532 for (i = 0; i < 3; ++i) { 533 static const char axis[] = "XYZ"; 534 static const char pgaxis[] = "ZYZXYX"; 535 unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F; 536 unsigned fine = le16_to_cpu(fab_data1[i]); 537 unsigned sens = le16_to_cpu(fab_data1[i + 3]); 538 unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]); 539 unsigned pgain2 = pgain1 >> 8; 540 541 pgain1 &= 0xFF; 542 543 dev_info(&ak8974->i2c->dev, 544 "factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n", 545 axis[i], offz, sens, fine, pgaxis[i * 2], 546 pgain1, pgaxis[i * 2 + 1], pgain2); 547 } 548 } 549 550 return 0; 551 } 552 553 static int ak8974_measure_channel(struct ak8974 *ak8974, unsigned long address, 554 int *val) 555 { 556 __le16 hw_values[3]; 557 int ret; 558 559 pm_runtime_get_sync(&ak8974->i2c->dev); 560 mutex_lock(&ak8974->lock); 561 562 /* 563 * We read all axes and discard all but one, for optimized 564 * reading, use the triggered buffer. 565 */ 566 ret = ak8974_trigmeas(ak8974); 567 if (ret) 568 goto out_unlock; 569 ret = ak8974_getresult(ak8974, hw_values); 570 if (ret) 571 goto out_unlock; 572 /* 573 * This explicit cast to (s16) is necessary as the measurement 574 * is done in 2's complement with positive and negative values. 575 * The following assignment to *val will then convert the signed 576 * s16 value to a signed int value. 577 */ 578 *val = (s16)le16_to_cpu(hw_values[address]); 579 out_unlock: 580 mutex_unlock(&ak8974->lock); 581 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 582 583 return ret; 584 } 585 586 static int ak8974_read_raw(struct iio_dev *indio_dev, 587 struct iio_chan_spec const *chan, 588 int *val, int *val2, 589 long mask) 590 { 591 struct ak8974 *ak8974 = iio_priv(indio_dev); 592 int ret; 593 594 switch (mask) { 595 case IIO_CHAN_INFO_RAW: 596 if (chan->address > 2) { 597 dev_err(&ak8974->i2c->dev, "faulty channel address\n"); 598 return -EIO; 599 } 600 ret = ak8974_measure_channel(ak8974, chan->address, val); 601 if (ret) 602 return ret; 603 return IIO_VAL_INT; 604 case IIO_CHAN_INFO_SCALE: 605 switch (ak8974->variant) { 606 case AK8974_WHOAMI_VALUE_AMI306: 607 case AK8974_WHOAMI_VALUE_AMI305: 608 /* 609 * The datasheet for AMI305 and AMI306, page 6 610 * specifies the range of the sensor to be 611 * +/- 12 Gauss. 612 */ 613 *val = 12; 614 /* 615 * 12 bits are used, +/- 2^11 616 * [ -2048 .. 2047 ] (manual page 20) 617 * [ 0xf800 .. 0x07ff ] 618 */ 619 *val2 = 11; 620 return IIO_VAL_FRACTIONAL_LOG2; 621 case AK8974_WHOAMI_VALUE_HSCDTD008A: 622 /* 623 * The datasheet for HSCDTF008A, page 3 specifies the 624 * range of the sensor as +/- 2.4 mT per axis, which 625 * corresponds to +/- 2400 uT = +/- 24 Gauss. 626 */ 627 *val = 24; 628 /* 629 * 15 bits are used (set up in CTRL4), +/- 2^14 630 * [ -16384 .. 16383 ] (manual page 24) 631 * [ 0xc000 .. 0x3fff ] 632 */ 633 *val2 = 14; 634 return IIO_VAL_FRACTIONAL_LOG2; 635 default: 636 /* GUESSING +/- 12 Gauss */ 637 *val = 12; 638 /* GUESSING 12 bits ADC +/- 2^11 */ 639 *val2 = 11; 640 return IIO_VAL_FRACTIONAL_LOG2; 641 } 642 break; 643 default: 644 /* Unknown request */ 645 break; 646 } 647 648 return -EINVAL; 649 } 650 651 static void ak8974_fill_buffer(struct iio_dev *indio_dev) 652 { 653 struct ak8974 *ak8974 = iio_priv(indio_dev); 654 int ret; 655 656 pm_runtime_get_sync(&ak8974->i2c->dev); 657 mutex_lock(&ak8974->lock); 658 659 ret = ak8974_trigmeas(ak8974); 660 if (ret) { 661 dev_err(&ak8974->i2c->dev, "error triggering measure\n"); 662 goto out_unlock; 663 } 664 ret = ak8974_getresult(ak8974, ak8974->scan.channels); 665 if (ret) { 666 dev_err(&ak8974->i2c->dev, "error getting measures\n"); 667 goto out_unlock; 668 } 669 670 iio_push_to_buffers_with_ts(indio_dev, &ak8974->scan, sizeof(ak8974->scan), 671 iio_get_time_ns(indio_dev)); 672 673 out_unlock: 674 mutex_unlock(&ak8974->lock); 675 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 676 } 677 678 static irqreturn_t ak8974_handle_trigger(int irq, void *p) 679 { 680 const struct iio_poll_func *pf = p; 681 struct iio_dev *indio_dev = pf->indio_dev; 682 683 ak8974_fill_buffer(indio_dev); 684 iio_trigger_notify_done(indio_dev->trig); 685 686 return IRQ_HANDLED; 687 } 688 689 static const struct iio_mount_matrix * 690 ak8974_get_mount_matrix(const struct iio_dev *indio_dev, 691 const struct iio_chan_spec *chan) 692 { 693 struct ak8974 *ak8974 = iio_priv(indio_dev); 694 695 return &ak8974->orientation; 696 } 697 698 static const struct iio_chan_spec_ext_info ak8974_ext_info[] = { 699 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix), 700 { } 701 }; 702 703 #define AK8974_AXIS_CHANNEL(axis, index, bits) \ 704 { \ 705 .type = IIO_MAGN, \ 706 .modified = 1, \ 707 .channel2 = IIO_MOD_##axis, \ 708 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 709 BIT(IIO_CHAN_INFO_SCALE), \ 710 .ext_info = ak8974_ext_info, \ 711 .address = index, \ 712 .scan_index = index, \ 713 .scan_type = { \ 714 .sign = 's', \ 715 .realbits = bits, \ 716 .storagebits = 16, \ 717 .endianness = IIO_LE \ 718 }, \ 719 } 720 721 /* 722 * We have no datasheet for the AK8974 but we guess that its 723 * ADC is 12 bits. The AMI305 and AMI306 certainly has 12bit 724 * ADC. 725 */ 726 static const struct iio_chan_spec ak8974_12_bits_channels[] = { 727 AK8974_AXIS_CHANNEL(X, 0, 12), 728 AK8974_AXIS_CHANNEL(Y, 1, 12), 729 AK8974_AXIS_CHANNEL(Z, 2, 12), 730 IIO_CHAN_SOFT_TIMESTAMP(3), 731 }; 732 733 /* 734 * The HSCDTD008A has 15 bits resolution the way we set it up 735 * in CTRL4. 736 */ 737 static const struct iio_chan_spec ak8974_15_bits_channels[] = { 738 AK8974_AXIS_CHANNEL(X, 0, 15), 739 AK8974_AXIS_CHANNEL(Y, 1, 15), 740 AK8974_AXIS_CHANNEL(Z, 2, 15), 741 IIO_CHAN_SOFT_TIMESTAMP(3), 742 }; 743 744 static const unsigned long ak8974_scan_masks[] = { 0x7, 0 }; 745 746 static const struct iio_info ak8974_info = { 747 .read_raw = &ak8974_read_raw, 748 }; 749 750 static bool ak8974_writeable_reg(struct device *dev, unsigned int reg) 751 { 752 struct i2c_client *i2c = to_i2c_client(dev); 753 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 754 struct ak8974 *ak8974 = iio_priv(indio_dev); 755 756 switch (reg) { 757 case AK8974_CTRL1: 758 case AK8974_CTRL2: 759 case AK8974_CTRL3: 760 case AK8974_INT_CTRL: 761 case AK8974_INT_THRES: 762 case AK8974_INT_THRES + 1: 763 return true; 764 case AK8974_PRESET: 765 case AK8974_PRESET + 1: 766 return ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A; 767 case AK8974_OFFSET_X: 768 case AK8974_OFFSET_X + 1: 769 case AK8974_OFFSET_Y: 770 case AK8974_OFFSET_Y + 1: 771 case AK8974_OFFSET_Z: 772 case AK8974_OFFSET_Z + 1: 773 return ak8974->variant == AK8974_WHOAMI_VALUE_AK8974 || 774 ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A; 775 case AMI305_OFFSET_X: 776 case AMI305_OFFSET_X + 1: 777 case AMI305_OFFSET_Y: 778 case AMI305_OFFSET_Y + 1: 779 case AMI305_OFFSET_Z: 780 case AMI305_OFFSET_Z + 1: 781 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 || 782 ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; 783 case AMI306_CTRL4: 784 case AMI306_CTRL4 + 1: 785 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; 786 default: 787 return false; 788 } 789 } 790 791 static bool ak8974_precious_reg(struct device *dev, unsigned int reg) 792 { 793 return reg == AK8974_INT_CLEAR; 794 } 795 796 static const struct regmap_config ak8974_regmap_config = { 797 .reg_bits = 8, 798 .val_bits = 8, 799 .max_register = 0xff, 800 .writeable_reg = ak8974_writeable_reg, 801 .precious_reg = ak8974_precious_reg, 802 }; 803 804 static int ak8974_probe(struct i2c_client *i2c) 805 { 806 struct iio_dev *indio_dev; 807 struct ak8974 *ak8974; 808 unsigned long irq_trig; 809 int irq = i2c->irq; 810 int ret; 811 812 /* Register with IIO */ 813 indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974)); 814 if (indio_dev == NULL) 815 return -ENOMEM; 816 817 ak8974 = iio_priv(indio_dev); 818 i2c_set_clientdata(i2c, indio_dev); 819 ak8974->i2c = i2c; 820 mutex_init(&ak8974->lock); 821 822 ret = iio_read_mount_matrix(&i2c->dev, &ak8974->orientation); 823 if (ret) 824 return ret; 825 826 ak8974->regs[0].supply = ak8974_reg_avdd; 827 ak8974->regs[1].supply = ak8974_reg_dvdd; 828 829 ret = devm_regulator_bulk_get(&i2c->dev, 830 ARRAY_SIZE(ak8974->regs), 831 ak8974->regs); 832 if (ret < 0) 833 return dev_err_probe(&i2c->dev, ret, "cannot get regulators\n"); 834 835 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 836 if (ret < 0) { 837 dev_err(&i2c->dev, "cannot enable regulators\n"); 838 return ret; 839 } 840 841 /* Take runtime PM online */ 842 pm_runtime_get_noresume(&i2c->dev); 843 pm_runtime_set_active(&i2c->dev); 844 pm_runtime_enable(&i2c->dev); 845 846 ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config); 847 if (IS_ERR(ak8974->map)) { 848 dev_err(&i2c->dev, "failed to allocate register map\n"); 849 pm_runtime_put_noidle(&i2c->dev); 850 pm_runtime_disable(&i2c->dev); 851 return PTR_ERR(ak8974->map); 852 } 853 854 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 855 if (ret) { 856 dev_err(&i2c->dev, "could not power on\n"); 857 goto disable_pm; 858 } 859 860 ret = ak8974_detect(ak8974); 861 if (ret) { 862 dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n"); 863 goto disable_pm; 864 } 865 866 ret = ak8974_selftest(ak8974); 867 if (ret) 868 dev_err(&i2c->dev, "selftest failed (continuing anyway)\n"); 869 870 ret = ak8974_reset(ak8974); 871 if (ret) { 872 dev_err(&i2c->dev, "AK8974 reset failed\n"); 873 goto disable_pm; 874 } 875 876 switch (ak8974->variant) { 877 case AK8974_WHOAMI_VALUE_AMI306: 878 case AK8974_WHOAMI_VALUE_AMI305: 879 indio_dev->channels = ak8974_12_bits_channels; 880 indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels); 881 break; 882 case AK8974_WHOAMI_VALUE_HSCDTD008A: 883 indio_dev->channels = ak8974_15_bits_channels; 884 indio_dev->num_channels = ARRAY_SIZE(ak8974_15_bits_channels); 885 break; 886 default: 887 indio_dev->channels = ak8974_12_bits_channels; 888 indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels); 889 break; 890 } 891 indio_dev->info = &ak8974_info; 892 indio_dev->available_scan_masks = ak8974_scan_masks; 893 indio_dev->modes = INDIO_DIRECT_MODE; 894 indio_dev->name = ak8974->name; 895 896 ret = iio_triggered_buffer_setup(indio_dev, NULL, 897 ak8974_handle_trigger, 898 NULL); 899 if (ret) { 900 dev_err(&i2c->dev, "triggered buffer setup failed\n"); 901 goto disable_pm; 902 } 903 904 /* If we have a valid DRDY IRQ, make use of it */ 905 if (irq > 0) { 906 irq_trig = irq_get_trigger_type(irq); 907 if (irq_trig == IRQF_TRIGGER_RISING) { 908 dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n"); 909 } else if (irq_trig == IRQF_TRIGGER_FALLING) { 910 ak8974->drdy_active_low = true; 911 dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n"); 912 } else { 913 irq_trig = IRQF_TRIGGER_RISING; 914 } 915 irq_trig |= IRQF_ONESHOT; 916 irq_trig |= IRQF_SHARED; 917 918 ret = devm_request_threaded_irq(&i2c->dev, 919 irq, 920 ak8974_drdy_irq, 921 ak8974_drdy_irq_thread, 922 irq_trig, 923 ak8974->name, 924 ak8974); 925 if (ret) 926 goto no_irq; 927 ak8974->drdy_irq = true; 928 } 929 930 no_irq: 931 ret = iio_device_register(indio_dev); 932 if (ret) { 933 dev_err(&i2c->dev, "device register failed\n"); 934 goto cleanup_buffer; 935 } 936 937 pm_runtime_set_autosuspend_delay(&i2c->dev, 938 AK8974_AUTOSUSPEND_DELAY); 939 pm_runtime_use_autosuspend(&i2c->dev); 940 pm_runtime_put(&i2c->dev); 941 942 return 0; 943 944 cleanup_buffer: 945 iio_triggered_buffer_cleanup(indio_dev); 946 disable_pm: 947 pm_runtime_put_noidle(&i2c->dev); 948 pm_runtime_disable(&i2c->dev); 949 ak8974_set_power(ak8974, AK8974_PWR_OFF); 950 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 951 952 return ret; 953 } 954 955 static void ak8974_remove(struct i2c_client *i2c) 956 { 957 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 958 struct ak8974 *ak8974 = iio_priv(indio_dev); 959 960 iio_device_unregister(indio_dev); 961 iio_triggered_buffer_cleanup(indio_dev); 962 pm_runtime_get_sync(&i2c->dev); 963 pm_runtime_put_noidle(&i2c->dev); 964 pm_runtime_disable(&i2c->dev); 965 ak8974_set_power(ak8974, AK8974_PWR_OFF); 966 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 967 } 968 969 static int ak8974_runtime_suspend(struct device *dev) 970 { 971 struct ak8974 *ak8974 = 972 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 973 974 ak8974_set_power(ak8974, AK8974_PWR_OFF); 975 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 976 977 return 0; 978 } 979 980 static int ak8974_runtime_resume(struct device *dev) 981 { 982 struct ak8974 *ak8974 = 983 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 984 int ret; 985 986 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 987 if (ret) 988 return ret; 989 msleep(AK8974_POWERON_DELAY); 990 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 991 if (ret) 992 goto out_regulator_disable; 993 994 ret = ak8974_configure(ak8974); 995 if (ret) 996 goto out_disable_power; 997 998 return 0; 999 1000 out_disable_power: 1001 ak8974_set_power(ak8974, AK8974_PWR_OFF); 1002 out_regulator_disable: 1003 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 1004 1005 return ret; 1006 } 1007 1008 static DEFINE_RUNTIME_DEV_PM_OPS(ak8974_dev_pm_ops, ak8974_runtime_suspend, 1009 ak8974_runtime_resume, NULL); 1010 1011 static const struct i2c_device_id ak8974_id[] = { 1012 { .name = "ami305" }, 1013 { .name = "ami306" }, 1014 { .name = "ak8974" }, 1015 { .name = "hscdtd008a" }, 1016 { } 1017 }; 1018 MODULE_DEVICE_TABLE(i2c, ak8974_id); 1019 1020 static const struct of_device_id ak8974_of_match[] = { 1021 { .compatible = "asahi-kasei,ak8974", }, 1022 { .compatible = "alps,hscdtd008a", }, 1023 { } 1024 }; 1025 MODULE_DEVICE_TABLE(of, ak8974_of_match); 1026 1027 static struct i2c_driver ak8974_driver = { 1028 .driver = { 1029 .name = "ak8974", 1030 .pm = pm_ptr(&ak8974_dev_pm_ops), 1031 .of_match_table = ak8974_of_match, 1032 }, 1033 .probe = ak8974_probe, 1034 .remove = ak8974_remove, 1035 .id_table = ak8974_id, 1036 }; 1037 module_i2c_driver(ak8974_driver); 1038 1039 MODULE_DESCRIPTION("AK8974 and AMI30x 3-axis magnetometer driver"); 1040 MODULE_AUTHOR("Samu Onkalo"); 1041 MODULE_AUTHOR("Linus Walleij"); 1042 MODULE_LICENSE("GPL v2"); 1043