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 53 #define AK8974_DATA_X 0x10 54 #define AK8974_DATA_Y 0x12 55 #define AK8974_DATA_Z 0x14 56 #define AK8974_INT_SRC 0x16 57 #define AK8974_STATUS 0x18 58 #define AK8974_INT_CLEAR 0x1A 59 #define AK8974_CTRL1 0x1B 60 #define AK8974_CTRL2 0x1C 61 #define AK8974_CTRL3 0x1D 62 #define AK8974_INT_CTRL 0x1E 63 #define AK8974_INT_THRES 0x26 /* Absolute any axis value threshold */ 64 #define AK8974_PRESET 0x30 65 66 /* AK8974-specific offsets */ 67 #define AK8974_OFFSET_X 0x20 68 #define AK8974_OFFSET_Y 0x22 69 #define AK8974_OFFSET_Z 0x24 70 /* AMI305-specific offsets */ 71 #define AMI305_OFFSET_X 0x6C 72 #define AMI305_OFFSET_Y 0x72 73 #define AMI305_OFFSET_Z 0x78 74 75 /* Different temperature registers */ 76 #define AK8974_TEMP 0x31 77 #define AMI305_TEMP 0x60 78 79 /* AMI306-specific control register */ 80 #define AMI306_CTRL4 0x5C 81 82 /* AMI306 factory calibration data */ 83 84 /* fine axis sensitivity */ 85 #define AMI306_FINEOUTPUT_X 0x90 86 #define AMI306_FINEOUTPUT_Y 0x92 87 #define AMI306_FINEOUTPUT_Z 0x94 88 89 /* axis sensitivity */ 90 #define AMI306_SENS_X 0x96 91 #define AMI306_SENS_Y 0x98 92 #define AMI306_SENS_Z 0x9A 93 94 /* axis cross-interference */ 95 #define AMI306_GAIN_PARA_XZ 0x9C 96 #define AMI306_GAIN_PARA_XY 0x9D 97 #define AMI306_GAIN_PARA_YZ 0x9E 98 #define AMI306_GAIN_PARA_YX 0x9F 99 #define AMI306_GAIN_PARA_ZY 0xA0 100 #define AMI306_GAIN_PARA_ZX 0xA1 101 102 /* offset at ZERO magnetic field */ 103 #define AMI306_OFFZERO_X 0xF8 104 #define AMI306_OFFZERO_Y 0xFA 105 #define AMI306_OFFZERO_Z 0xFC 106 107 108 #define AK8974_INT_X_HIGH BIT(7) /* Axis over +threshold */ 109 #define AK8974_INT_Y_HIGH BIT(6) 110 #define AK8974_INT_Z_HIGH BIT(5) 111 #define AK8974_INT_X_LOW BIT(4) /* Axis below -threshold */ 112 #define AK8974_INT_Y_LOW BIT(3) 113 #define AK8974_INT_Z_LOW BIT(2) 114 #define AK8974_INT_RANGE BIT(1) /* Range overflow (any axis) */ 115 116 #define AK8974_STATUS_DRDY BIT(6) /* Data ready */ 117 #define AK8974_STATUS_OVERRUN BIT(5) /* Data overrun */ 118 #define AK8974_STATUS_INT BIT(4) /* Interrupt occurred */ 119 120 #define AK8974_CTRL1_POWER BIT(7) /* 0 = standby; 1 = active */ 121 #define AK8974_CTRL1_RATE BIT(4) /* 0 = 10 Hz; 1 = 20 Hz */ 122 #define AK8974_CTRL1_FORCE_EN BIT(1) /* 0 = normal; 1 = force */ 123 #define AK8974_CTRL1_MODE2 BIT(0) /* 0 */ 124 125 #define AK8974_CTRL2_INT_EN BIT(4) /* 1 = enable interrupts */ 126 #define AK8974_CTRL2_DRDY_EN BIT(3) /* 1 = enable data ready signal */ 127 #define AK8974_CTRL2_DRDY_POL BIT(2) /* 1 = data ready active high */ 128 #define AK8974_CTRL2_RESDEF (AK8974_CTRL2_DRDY_POL) 129 130 #define AK8974_CTRL3_RESET BIT(7) /* Software reset */ 131 #define AK8974_CTRL3_FORCE BIT(6) /* Start forced measurement */ 132 #define AK8974_CTRL3_SELFTEST BIT(4) /* Set selftest register */ 133 #define AK8974_CTRL3_RESDEF 0x00 134 135 #define AK8974_INT_CTRL_XEN BIT(7) /* Enable interrupt for this axis */ 136 #define AK8974_INT_CTRL_YEN BIT(6) 137 #define AK8974_INT_CTRL_ZEN BIT(5) 138 #define AK8974_INT_CTRL_XYZEN (BIT(7)|BIT(6)|BIT(5)) 139 #define AK8974_INT_CTRL_POL BIT(3) /* 0 = active low; 1 = active high */ 140 #define AK8974_INT_CTRL_PULSE BIT(1) /* 0 = latched; 1 = pulse (50 usec) */ 141 #define AK8974_INT_CTRL_RESDEF (AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL) 142 143 /* The AMI305 has elaborate FW version and serial number registers */ 144 #define AMI305_VER 0xE8 145 #define AMI305_SN 0xEA 146 147 #define AK8974_MAX_RANGE 2048 148 149 #define AK8974_POWERON_DELAY 50 150 #define AK8974_ACTIVATE_DELAY 1 151 #define AK8974_SELFTEST_DELAY 1 152 /* 153 * Set the autosuspend to two orders of magnitude larger than the poweron 154 * delay to make sane reasonable power tradeoff savings (5 seconds in 155 * this case). 156 */ 157 #define AK8974_AUTOSUSPEND_DELAY 5000 158 159 #define AK8974_MEASTIME 3 160 161 #define AK8974_PWR_ON 1 162 #define AK8974_PWR_OFF 0 163 164 /** 165 * struct ak8974 - state container for the AK8974 driver 166 * @i2c: parent I2C client 167 * @orientation: mounting matrix, flipped axis etc 168 * @map: regmap to access the AK8974 registers over I2C 169 * @regs: the avdd and dvdd power regulators 170 * @name: the name of the part 171 * @variant: the whoami ID value (for selecting code paths) 172 * @lock: locks the magnetometer for exclusive use during a measurement 173 * @drdy_irq: uses the DRDY IRQ line 174 * @drdy_complete: completion for DRDY 175 * @drdy_active_low: the DRDY IRQ is active low 176 */ 177 struct ak8974 { 178 struct i2c_client *i2c; 179 struct iio_mount_matrix orientation; 180 struct regmap *map; 181 struct regulator_bulk_data regs[2]; 182 const char *name; 183 u8 variant; 184 struct mutex lock; 185 bool drdy_irq; 186 struct completion drdy_complete; 187 bool drdy_active_low; 188 }; 189 190 static const char ak8974_reg_avdd[] = "avdd"; 191 static const char ak8974_reg_dvdd[] = "dvdd"; 192 193 static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val) 194 { 195 int ret; 196 __le16 bulk; 197 198 ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2); 199 if (ret) 200 return ret; 201 *val = le16_to_cpu(bulk); 202 203 return 0; 204 } 205 206 static int ak8974_set_u16_val(struct ak8974 *ak8974, u8 reg, u16 val) 207 { 208 __le16 bulk = cpu_to_le16(val); 209 210 return regmap_bulk_write(ak8974->map, reg, &bulk, 2); 211 } 212 213 static int ak8974_set_power(struct ak8974 *ak8974, bool mode) 214 { 215 int ret; 216 u8 val; 217 218 val = mode ? AK8974_CTRL1_POWER : 0; 219 val |= AK8974_CTRL1_FORCE_EN; 220 ret = regmap_write(ak8974->map, AK8974_CTRL1, val); 221 if (ret < 0) 222 return ret; 223 224 if (mode) 225 msleep(AK8974_ACTIVATE_DELAY); 226 227 return 0; 228 } 229 230 static int ak8974_reset(struct ak8974 *ak8974) 231 { 232 int ret; 233 234 /* Power on to get register access. Sets CTRL1 reg to reset state */ 235 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 236 if (ret) 237 return ret; 238 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF); 239 if (ret) 240 return ret; 241 ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF); 242 if (ret) 243 return ret; 244 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, 245 AK8974_INT_CTRL_RESDEF); 246 if (ret) 247 return ret; 248 249 /* After reset, power off is default state */ 250 return ak8974_set_power(ak8974, AK8974_PWR_OFF); 251 } 252 253 static int ak8974_configure(struct ak8974 *ak8974) 254 { 255 int ret; 256 257 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN | 258 AK8974_CTRL2_INT_EN); 259 if (ret) 260 return ret; 261 ret = regmap_write(ak8974->map, AK8974_CTRL3, 0); 262 if (ret) 263 return ret; 264 if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI306) { 265 /* magic from datasheet: set high-speed measurement mode */ 266 ret = ak8974_set_u16_val(ak8974, AMI306_CTRL4, 0xA07E); 267 if (ret) 268 return ret; 269 } 270 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL); 271 if (ret) 272 return ret; 273 274 return regmap_write(ak8974->map, AK8974_PRESET, 0); 275 } 276 277 static int ak8974_trigmeas(struct ak8974 *ak8974) 278 { 279 unsigned int clear; 280 u8 mask; 281 u8 val; 282 int ret; 283 284 /* Clear any previous measurement overflow status */ 285 ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear); 286 if (ret) 287 return ret; 288 289 /* If we have a DRDY IRQ line, use it */ 290 if (ak8974->drdy_irq) { 291 mask = AK8974_CTRL2_INT_EN | 292 AK8974_CTRL2_DRDY_EN | 293 AK8974_CTRL2_DRDY_POL; 294 val = AK8974_CTRL2_DRDY_EN; 295 296 if (!ak8974->drdy_active_low) 297 val |= AK8974_CTRL2_DRDY_POL; 298 299 init_completion(&ak8974->drdy_complete); 300 ret = regmap_update_bits(ak8974->map, AK8974_CTRL2, 301 mask, val); 302 if (ret) 303 return ret; 304 } 305 306 /* Force a measurement */ 307 return regmap_update_bits(ak8974->map, 308 AK8974_CTRL3, 309 AK8974_CTRL3_FORCE, 310 AK8974_CTRL3_FORCE); 311 } 312 313 static int ak8974_await_drdy(struct ak8974 *ak8974) 314 { 315 int timeout = 2; 316 unsigned int val; 317 int ret; 318 319 if (ak8974->drdy_irq) { 320 ret = wait_for_completion_timeout(&ak8974->drdy_complete, 321 1 + msecs_to_jiffies(1000)); 322 if (!ret) { 323 dev_err(&ak8974->i2c->dev, 324 "timeout waiting for DRDY IRQ\n"); 325 return -ETIMEDOUT; 326 } 327 return 0; 328 } 329 330 /* Default delay-based poll loop */ 331 do { 332 msleep(AK8974_MEASTIME); 333 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 334 if (ret < 0) 335 return ret; 336 if (val & AK8974_STATUS_DRDY) 337 return 0; 338 } while (--timeout); 339 340 dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n"); 341 return -ETIMEDOUT; 342 } 343 344 static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result) 345 { 346 unsigned int src; 347 int ret; 348 349 ret = ak8974_await_drdy(ak8974); 350 if (ret) 351 return ret; 352 ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src); 353 if (ret < 0) 354 return ret; 355 356 /* Out of range overflow! Strong magnet close? */ 357 if (src & AK8974_INT_RANGE) { 358 dev_err(&ak8974->i2c->dev, 359 "range overflow in sensor\n"); 360 return -ERANGE; 361 } 362 363 ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6); 364 if (ret) 365 return ret; 366 367 return ret; 368 } 369 370 static irqreturn_t ak8974_drdy_irq(int irq, void *d) 371 { 372 struct ak8974 *ak8974 = d; 373 374 if (!ak8974->drdy_irq) 375 return IRQ_NONE; 376 377 /* TODO: timestamp here to get good measurement stamps */ 378 return IRQ_WAKE_THREAD; 379 } 380 381 static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d) 382 { 383 struct ak8974 *ak8974 = d; 384 unsigned int val; 385 int ret; 386 387 /* Check if this was a DRDY from us */ 388 ret = regmap_read(ak8974->map, AK8974_STATUS, &val); 389 if (ret < 0) { 390 dev_err(&ak8974->i2c->dev, "error reading DRDY status\n"); 391 return IRQ_HANDLED; 392 } 393 if (val & AK8974_STATUS_DRDY) { 394 /* Yes this was our IRQ */ 395 complete(&ak8974->drdy_complete); 396 return IRQ_HANDLED; 397 } 398 399 /* We may be on a shared IRQ, let the next client check */ 400 return IRQ_NONE; 401 } 402 403 static int ak8974_selftest(struct ak8974 *ak8974) 404 { 405 struct device *dev = &ak8974->i2c->dev; 406 unsigned int val; 407 int ret; 408 409 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 410 if (ret) 411 return ret; 412 if (val != AK8974_SELFTEST_IDLE) { 413 dev_err(dev, "selftest not idle before test\n"); 414 return -EIO; 415 } 416 417 /* Trigger self-test */ 418 ret = regmap_update_bits(ak8974->map, 419 AK8974_CTRL3, 420 AK8974_CTRL3_SELFTEST, 421 AK8974_CTRL3_SELFTEST); 422 if (ret) { 423 dev_err(dev, "could not write CTRL3\n"); 424 return ret; 425 } 426 427 msleep(AK8974_SELFTEST_DELAY); 428 429 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 430 if (ret) 431 return ret; 432 if (val != AK8974_SELFTEST_OK) { 433 dev_err(dev, "selftest result NOT OK (%02x)\n", val); 434 return -EIO; 435 } 436 437 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); 438 if (ret) 439 return ret; 440 if (val != AK8974_SELFTEST_IDLE) { 441 dev_err(dev, "selftest not idle after test (%02x)\n", val); 442 return -EIO; 443 } 444 dev_dbg(dev, "passed self-test\n"); 445 446 return 0; 447 } 448 449 static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg, 450 __le16 *tab, size_t tab_size) 451 { 452 int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size); 453 if (ret) { 454 memset(tab, 0xFF, tab_size); 455 dev_warn(&ak8974->i2c->dev, 456 "can't read calibration data (regs %u..%zu): %d\n", 457 reg, reg + tab_size - 1, ret); 458 } else { 459 add_device_randomness(tab, tab_size); 460 } 461 } 462 463 static int ak8974_detect(struct ak8974 *ak8974) 464 { 465 unsigned int whoami; 466 const char *name; 467 int ret; 468 unsigned int fw; 469 u16 sn; 470 471 ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami); 472 if (ret) 473 return ret; 474 475 name = "ami305"; 476 477 switch (whoami) { 478 case AK8974_WHOAMI_VALUE_AMI306: 479 name = "ami306"; 480 /* fall-through */ 481 case AK8974_WHOAMI_VALUE_AMI305: 482 ret = regmap_read(ak8974->map, AMI305_VER, &fw); 483 if (ret) 484 return ret; 485 fw &= 0x7f; /* only bits 0 thru 6 valid */ 486 ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn); 487 if (ret) 488 return ret; 489 add_device_randomness(&sn, sizeof(sn)); 490 dev_info(&ak8974->i2c->dev, 491 "detected %s, FW ver %02x, S/N: %04x\n", 492 name, fw, sn); 493 break; 494 case AK8974_WHOAMI_VALUE_AK8974: 495 name = "ak8974"; 496 dev_info(&ak8974->i2c->dev, "detected AK8974\n"); 497 break; 498 default: 499 dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ", 500 whoami); 501 return -ENODEV; 502 } 503 504 ak8974->name = name; 505 ak8974->variant = whoami; 506 507 if (whoami == AK8974_WHOAMI_VALUE_AMI306) { 508 __le16 fab_data1[9], fab_data2[3]; 509 int i; 510 511 ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X, 512 fab_data1, sizeof(fab_data1)); 513 ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X, 514 fab_data2, sizeof(fab_data2)); 515 516 for (i = 0; i < 3; ++i) { 517 static const char axis[3] = "XYZ"; 518 static const char pgaxis[6] = "ZYZXYX"; 519 unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F; 520 unsigned fine = le16_to_cpu(fab_data1[i]); 521 unsigned sens = le16_to_cpu(fab_data1[i + 3]); 522 unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]); 523 unsigned pgain2 = pgain1 >> 8; 524 525 pgain1 &= 0xFF; 526 527 dev_info(&ak8974->i2c->dev, 528 "factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n", 529 axis[i], offz, sens, fine, pgaxis[i * 2], 530 pgain1, pgaxis[i * 2 + 1], pgain2); 531 } 532 } 533 534 return 0; 535 } 536 537 static int ak8974_read_raw(struct iio_dev *indio_dev, 538 struct iio_chan_spec const *chan, 539 int *val, int *val2, 540 long mask) 541 { 542 struct ak8974 *ak8974 = iio_priv(indio_dev); 543 __le16 hw_values[3]; 544 int ret = -EINVAL; 545 546 pm_runtime_get_sync(&ak8974->i2c->dev); 547 mutex_lock(&ak8974->lock); 548 549 switch (mask) { 550 case IIO_CHAN_INFO_RAW: 551 if (chan->address > 2) { 552 dev_err(&ak8974->i2c->dev, "faulty channel address\n"); 553 ret = -EIO; 554 goto out_unlock; 555 } 556 ret = ak8974_trigmeas(ak8974); 557 if (ret) 558 goto out_unlock; 559 ret = ak8974_getresult(ak8974, hw_values); 560 if (ret) 561 goto out_unlock; 562 563 /* 564 * We read all axes and discard all but one, for optimized 565 * reading, use the triggered buffer. 566 */ 567 *val = le16_to_cpu(hw_values[chan->address]); 568 569 ret = IIO_VAL_INT; 570 } 571 572 out_unlock: 573 mutex_unlock(&ak8974->lock); 574 pm_runtime_mark_last_busy(&ak8974->i2c->dev); 575 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 576 577 return ret; 578 } 579 580 static void ak8974_fill_buffer(struct iio_dev *indio_dev) 581 { 582 struct ak8974 *ak8974 = iio_priv(indio_dev); 583 int ret; 584 __le16 hw_values[8]; /* Three axes + 64bit padding */ 585 586 pm_runtime_get_sync(&ak8974->i2c->dev); 587 mutex_lock(&ak8974->lock); 588 589 ret = ak8974_trigmeas(ak8974); 590 if (ret) { 591 dev_err(&ak8974->i2c->dev, "error triggering measure\n"); 592 goto out_unlock; 593 } 594 ret = ak8974_getresult(ak8974, hw_values); 595 if (ret) { 596 dev_err(&ak8974->i2c->dev, "error getting measures\n"); 597 goto out_unlock; 598 } 599 600 iio_push_to_buffers_with_timestamp(indio_dev, hw_values, 601 iio_get_time_ns(indio_dev)); 602 603 out_unlock: 604 mutex_unlock(&ak8974->lock); 605 pm_runtime_mark_last_busy(&ak8974->i2c->dev); 606 pm_runtime_put_autosuspend(&ak8974->i2c->dev); 607 } 608 609 static irqreturn_t ak8974_handle_trigger(int irq, void *p) 610 { 611 const struct iio_poll_func *pf = p; 612 struct iio_dev *indio_dev = pf->indio_dev; 613 614 ak8974_fill_buffer(indio_dev); 615 iio_trigger_notify_done(indio_dev->trig); 616 617 return IRQ_HANDLED; 618 } 619 620 static const struct iio_mount_matrix * 621 ak8974_get_mount_matrix(const struct iio_dev *indio_dev, 622 const struct iio_chan_spec *chan) 623 { 624 struct ak8974 *ak8974 = iio_priv(indio_dev); 625 626 return &ak8974->orientation; 627 } 628 629 static const struct iio_chan_spec_ext_info ak8974_ext_info[] = { 630 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix), 631 { }, 632 }; 633 634 #define AK8974_AXIS_CHANNEL(axis, index) \ 635 { \ 636 .type = IIO_MAGN, \ 637 .modified = 1, \ 638 .channel2 = IIO_MOD_##axis, \ 639 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 640 .ext_info = ak8974_ext_info, \ 641 .address = index, \ 642 .scan_index = index, \ 643 .scan_type = { \ 644 .sign = 's', \ 645 .realbits = 16, \ 646 .storagebits = 16, \ 647 .endianness = IIO_LE \ 648 }, \ 649 } 650 651 static const struct iio_chan_spec ak8974_channels[] = { 652 AK8974_AXIS_CHANNEL(X, 0), 653 AK8974_AXIS_CHANNEL(Y, 1), 654 AK8974_AXIS_CHANNEL(Z, 2), 655 IIO_CHAN_SOFT_TIMESTAMP(3), 656 }; 657 658 static const unsigned long ak8974_scan_masks[] = { 0x7, 0 }; 659 660 static const struct iio_info ak8974_info = { 661 .read_raw = &ak8974_read_raw, 662 }; 663 664 static bool ak8974_writeable_reg(struct device *dev, unsigned int reg) 665 { 666 struct i2c_client *i2c = to_i2c_client(dev); 667 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 668 struct ak8974 *ak8974 = iio_priv(indio_dev); 669 670 switch (reg) { 671 case AK8974_CTRL1: 672 case AK8974_CTRL2: 673 case AK8974_CTRL3: 674 case AK8974_INT_CTRL: 675 case AK8974_INT_THRES: 676 case AK8974_INT_THRES + 1: 677 case AK8974_PRESET: 678 case AK8974_PRESET + 1: 679 return true; 680 case AK8974_OFFSET_X: 681 case AK8974_OFFSET_X + 1: 682 case AK8974_OFFSET_Y: 683 case AK8974_OFFSET_Y + 1: 684 case AK8974_OFFSET_Z: 685 case AK8974_OFFSET_Z + 1: 686 if (ak8974->variant == AK8974_WHOAMI_VALUE_AK8974) 687 return true; 688 return false; 689 case AMI305_OFFSET_X: 690 case AMI305_OFFSET_X + 1: 691 case AMI305_OFFSET_Y: 692 case AMI305_OFFSET_Y + 1: 693 case AMI305_OFFSET_Z: 694 case AMI305_OFFSET_Z + 1: 695 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 || 696 ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; 697 case AMI306_CTRL4: 698 case AMI306_CTRL4 + 1: 699 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; 700 default: 701 return false; 702 } 703 } 704 705 static bool ak8974_precious_reg(struct device *dev, unsigned int reg) 706 { 707 return reg == AK8974_INT_CLEAR; 708 } 709 710 static const struct regmap_config ak8974_regmap_config = { 711 .reg_bits = 8, 712 .val_bits = 8, 713 .max_register = 0xff, 714 .writeable_reg = ak8974_writeable_reg, 715 .precious_reg = ak8974_precious_reg, 716 }; 717 718 static int ak8974_probe(struct i2c_client *i2c, 719 const struct i2c_device_id *id) 720 { 721 struct iio_dev *indio_dev; 722 struct ak8974 *ak8974; 723 unsigned long irq_trig; 724 int irq = i2c->irq; 725 int ret; 726 727 /* Register with IIO */ 728 indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974)); 729 if (indio_dev == NULL) 730 return -ENOMEM; 731 732 ak8974 = iio_priv(indio_dev); 733 i2c_set_clientdata(i2c, indio_dev); 734 ak8974->i2c = i2c; 735 mutex_init(&ak8974->lock); 736 737 ret = iio_read_mount_matrix(&i2c->dev, "mount-matrix", 738 &ak8974->orientation); 739 if (ret) 740 return ret; 741 742 ak8974->regs[0].supply = ak8974_reg_avdd; 743 ak8974->regs[1].supply = ak8974_reg_dvdd; 744 745 ret = devm_regulator_bulk_get(&i2c->dev, 746 ARRAY_SIZE(ak8974->regs), 747 ak8974->regs); 748 if (ret < 0) { 749 dev_err(&i2c->dev, "cannot get regulators\n"); 750 return ret; 751 } 752 753 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 754 if (ret < 0) { 755 dev_err(&i2c->dev, "cannot enable regulators\n"); 756 return ret; 757 } 758 759 /* Take runtime PM online */ 760 pm_runtime_get_noresume(&i2c->dev); 761 pm_runtime_set_active(&i2c->dev); 762 pm_runtime_enable(&i2c->dev); 763 764 ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config); 765 if (IS_ERR(ak8974->map)) { 766 dev_err(&i2c->dev, "failed to allocate register map\n"); 767 return PTR_ERR(ak8974->map); 768 } 769 770 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 771 if (ret) { 772 dev_err(&i2c->dev, "could not power on\n"); 773 goto power_off; 774 } 775 776 ret = ak8974_detect(ak8974); 777 if (ret) { 778 dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n"); 779 goto power_off; 780 } 781 782 ret = ak8974_selftest(ak8974); 783 if (ret) 784 dev_err(&i2c->dev, "selftest failed (continuing anyway)\n"); 785 786 ret = ak8974_reset(ak8974); 787 if (ret) { 788 dev_err(&i2c->dev, "AK8974 reset failed\n"); 789 goto power_off; 790 } 791 792 pm_runtime_set_autosuspend_delay(&i2c->dev, 793 AK8974_AUTOSUSPEND_DELAY); 794 pm_runtime_use_autosuspend(&i2c->dev); 795 pm_runtime_put(&i2c->dev); 796 797 indio_dev->dev.parent = &i2c->dev; 798 indio_dev->channels = ak8974_channels; 799 indio_dev->num_channels = ARRAY_SIZE(ak8974_channels); 800 indio_dev->info = &ak8974_info; 801 indio_dev->available_scan_masks = ak8974_scan_masks; 802 indio_dev->modes = INDIO_DIRECT_MODE; 803 indio_dev->name = ak8974->name; 804 805 ret = iio_triggered_buffer_setup(indio_dev, NULL, 806 ak8974_handle_trigger, 807 NULL); 808 if (ret) { 809 dev_err(&i2c->dev, "triggered buffer setup failed\n"); 810 goto disable_pm; 811 } 812 813 /* If we have a valid DRDY IRQ, make use of it */ 814 if (irq > 0) { 815 irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq)); 816 if (irq_trig == IRQF_TRIGGER_RISING) { 817 dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n"); 818 } else if (irq_trig == IRQF_TRIGGER_FALLING) { 819 ak8974->drdy_active_low = true; 820 dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n"); 821 } else { 822 irq_trig = IRQF_TRIGGER_RISING; 823 } 824 irq_trig |= IRQF_ONESHOT; 825 irq_trig |= IRQF_SHARED; 826 827 ret = devm_request_threaded_irq(&i2c->dev, 828 irq, 829 ak8974_drdy_irq, 830 ak8974_drdy_irq_thread, 831 irq_trig, 832 ak8974->name, 833 ak8974); 834 if (ret) { 835 dev_err(&i2c->dev, "unable to request DRDY IRQ " 836 "- proceeding without IRQ\n"); 837 goto no_irq; 838 } 839 ak8974->drdy_irq = true; 840 } 841 842 no_irq: 843 ret = iio_device_register(indio_dev); 844 if (ret) { 845 dev_err(&i2c->dev, "device register failed\n"); 846 goto cleanup_buffer; 847 } 848 849 return 0; 850 851 cleanup_buffer: 852 iio_triggered_buffer_cleanup(indio_dev); 853 disable_pm: 854 pm_runtime_put_noidle(&i2c->dev); 855 pm_runtime_disable(&i2c->dev); 856 ak8974_set_power(ak8974, AK8974_PWR_OFF); 857 power_off: 858 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 859 860 return ret; 861 } 862 863 static int ak8974_remove(struct i2c_client *i2c) 864 { 865 struct iio_dev *indio_dev = i2c_get_clientdata(i2c); 866 struct ak8974 *ak8974 = iio_priv(indio_dev); 867 868 iio_device_unregister(indio_dev); 869 iio_triggered_buffer_cleanup(indio_dev); 870 pm_runtime_get_sync(&i2c->dev); 871 pm_runtime_put_noidle(&i2c->dev); 872 pm_runtime_disable(&i2c->dev); 873 ak8974_set_power(ak8974, AK8974_PWR_OFF); 874 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 875 876 return 0; 877 } 878 879 static int __maybe_unused ak8974_runtime_suspend(struct device *dev) 880 { 881 struct ak8974 *ak8974 = 882 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 883 884 ak8974_set_power(ak8974, AK8974_PWR_OFF); 885 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 886 887 return 0; 888 } 889 890 static int __maybe_unused ak8974_runtime_resume(struct device *dev) 891 { 892 struct ak8974 *ak8974 = 893 iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 894 int ret; 895 896 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 897 if (ret) 898 return ret; 899 msleep(AK8974_POWERON_DELAY); 900 ret = ak8974_set_power(ak8974, AK8974_PWR_ON); 901 if (ret) 902 goto out_regulator_disable; 903 904 ret = ak8974_configure(ak8974); 905 if (ret) 906 goto out_disable_power; 907 908 return 0; 909 910 out_disable_power: 911 ak8974_set_power(ak8974, AK8974_PWR_OFF); 912 out_regulator_disable: 913 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); 914 915 return ret; 916 } 917 918 static const struct dev_pm_ops ak8974_dev_pm_ops = { 919 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, 920 pm_runtime_force_resume) 921 SET_RUNTIME_PM_OPS(ak8974_runtime_suspend, 922 ak8974_runtime_resume, NULL) 923 }; 924 925 static const struct i2c_device_id ak8974_id[] = { 926 {"ami305", 0 }, 927 {"ami306", 0 }, 928 {"ak8974", 0 }, 929 {} 930 }; 931 MODULE_DEVICE_TABLE(i2c, ak8974_id); 932 933 static const struct of_device_id ak8974_of_match[] = { 934 { .compatible = "asahi-kasei,ak8974", }, 935 {} 936 }; 937 MODULE_DEVICE_TABLE(of, ak8974_of_match); 938 939 static struct i2c_driver ak8974_driver = { 940 .driver = { 941 .name = "ak8974", 942 .pm = &ak8974_dev_pm_ops, 943 .of_match_table = of_match_ptr(ak8974_of_match), 944 }, 945 .probe = ak8974_probe, 946 .remove = ak8974_remove, 947 .id_table = ak8974_id, 948 }; 949 module_i2c_driver(ak8974_driver); 950 951 MODULE_DESCRIPTION("AK8974 and AMI30x 3-axis magnetometer driver"); 952 MODULE_AUTHOR("Samu Onkalo"); 953 MODULE_AUTHOR("Linus Walleij"); 954 MODULE_LICENSE("GPL v2"); 955