drivers/iio/magnetometer/ak8974.c

   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");