drivers/iio/magnetometer/ak8974.c

   1 /*
   2  * Driver for the Asahi Kasei EMD Corporation AK8974
   3  * and Aichi Steel AMI305 magnetometer chips.
   4  * Based on a patch from Samu Onkalo and the AK8975 IIO driver.
   5  *
   6  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
   7  * Copyright (c) 2010 NVIDIA Corporation.
   8  * Copyright (C) 2016 Linaro Ltd.
   9  *
  10  * Author: Samu Onkalo <samu.p.onkalo@nokia.com>
  11  * Author: Linus Walleij <linus.walleij@linaro.org>
  12  */
  13 #include <linux/module.h>
  14 #include <linux/kernel.h>
  15 #include <linux/i2c.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/irq.h> /* For irq_get_irq_data() */
  18 #include <linux/completion.h>
  19 #include <linux/err.h>
  20 #include <linux/mutex.h>
  21 #include <linux/delay.h>
  22 #include <linux/bitops.h>
  23 #include <linux/random.h>
  24 #include <linux/regmap.h>
  25 #include <linux/regulator/consumer.h>
  26 #include <linux/pm_runtime.h>
  27
  28 #include <linux/iio/iio.h>
  29 #include <linux/iio/sysfs.h>
  30 #include <linux/iio/buffer.h>
  31 #include <linux/iio/trigger.h>
  32 #include <linux/iio/trigger_consumer.h>
  33 #include <linux/iio/triggered_buffer.h>
  34
  35 /*
  36  * 16-bit registers are little-endian. LSB is at the address defined below
  37  * and MSB is at the next higher address.
  38  */
  39
  40 /* These registers are common for AK8974 and AMI30x */
  41 #define AK8974_SELFTEST         0x0C
  42 #define AK8974_SELFTEST_IDLE    0x55
  43 #define AK8974_SELFTEST_OK      0xAA
  44
  45 #define AK8974_INFO             0x0D
  46
  47 #define AK8974_WHOAMI           0x0F
  48 #define AK8974_WHOAMI_VALUE_AMI306 0x46
  49 #define AK8974_WHOAMI_VALUE_AMI305 0x47
  50 #define AK8974_WHOAMI_VALUE_AK8974 0x48
  51
  52 #define AK8974_DATA_X           0x10
  53 #define AK8974_DATA_Y           0x12
  54 #define AK8974_DATA_Z           0x14
  55 #define AK8974_INT_SRC          0x16
  56 #define AK8974_STATUS           0x18
  57 #define AK8974_INT_CLEAR        0x1A
  58 #define AK8974_CTRL1            0x1B
  59 #define AK8974_CTRL2            0x1C
  60 #define AK8974_CTRL3            0x1D
  61 #define AK8974_INT_CTRL         0x1E
  62 #define AK8974_INT_THRES        0x26  /* Absolute any axis value threshold */
  63 #define AK8974_PRESET           0x30
  64
  65 /* AK8974-specific offsets */
  66 #define AK8974_OFFSET_X         0x20
  67 #define AK8974_OFFSET_Y         0x22
  68 #define AK8974_OFFSET_Z         0x24
  69 /* AMI305-specific offsets */
  70 #define AMI305_OFFSET_X         0x6C
  71 #define AMI305_OFFSET_Y         0x72
  72 #define AMI305_OFFSET_Z         0x78
  73
  74 /* Different temperature registers */
  75 #define AK8974_TEMP             0x31
  76 #define AMI305_TEMP             0x60
  77
  78 /* AMI306-specific control register */
  79 #define AMI306_CTRL4            0x5C
  80
  81 /* AMI306 factory calibration data */
  82
  83 /* fine axis sensitivity */
  84 #define AMI306_FINEOUTPUT_X     0x90
  85 #define AMI306_FINEOUTPUT_Y     0x92
  86 #define AMI306_FINEOUTPUT_Z     0x94
  87
  88 /* axis sensitivity */
  89 #define AMI306_SENS_X           0x96
  90 #define AMI306_SENS_Y           0x98
  91 #define AMI306_SENS_Z           0x9A
  92
  93 /* axis cross-interference */
  94 #define AMI306_GAIN_PARA_XZ     0x9C
  95 #define AMI306_GAIN_PARA_XY     0x9D
  96 #define AMI306_GAIN_PARA_YZ     0x9E
  97 #define AMI306_GAIN_PARA_YX     0x9F
  98 #define AMI306_GAIN_PARA_ZY     0xA0
  99 #define AMI306_GAIN_PARA_ZX     0xA1
 100
 101 /* offset at ZERO magnetic field */
 102 #define AMI306_OFFZERO_X        0xF8
 103 #define AMI306_OFFZERO_Y        0xFA
 104 #define AMI306_OFFZERO_Z        0xFC
 105
 106
 107 #define AK8974_INT_X_HIGH       BIT(7) /* Axis over +threshold  */
 108 #define AK8974_INT_Y_HIGH       BIT(6)
 109 #define AK8974_INT_Z_HIGH       BIT(5)
 110 #define AK8974_INT_X_LOW        BIT(4) /* Axis below -threshold */
 111 #define AK8974_INT_Y_LOW        BIT(3)
 112 #define AK8974_INT_Z_LOW        BIT(2)
 113 #define AK8974_INT_RANGE        BIT(1) /* Range overflow (any axis) */
 114
 115 #define AK8974_STATUS_DRDY      BIT(6) /* Data ready */
 116 #define AK8974_STATUS_OVERRUN   BIT(5) /* Data overrun */
 117 #define AK8974_STATUS_INT       BIT(4) /* Interrupt occurred */
 118
 119 #define AK8974_CTRL1_POWER      BIT(7) /* 0 = standby; 1 = active */
 120 #define AK8974_CTRL1_RATE       BIT(4) /* 0 = 10 Hz; 1 = 20 Hz   */
 121 #define AK8974_CTRL1_FORCE_EN   BIT(1) /* 0 = normal; 1 = force  */
 122 #define AK8974_CTRL1_MODE2      BIT(0) /* 0 */
 123
 124 #define AK8974_CTRL2_INT_EN     BIT(4)  /* 1 = enable interrupts              */
 125 #define AK8974_CTRL2_DRDY_EN    BIT(3)  /* 1 = enable data ready signal */
 126 #define AK8974_CTRL2_DRDY_POL   BIT(2)  /* 1 = data ready active high   */
 127 #define AK8974_CTRL2_RESDEF     (AK8974_CTRL2_DRDY_POL)
 128
 129 #define AK8974_CTRL3_RESET      BIT(7) /* Software reset                  */
 130 #define AK8974_CTRL3_FORCE      BIT(6) /* Start forced measurement */
 131 #define AK8974_CTRL3_SELFTEST   BIT(4) /* Set selftest register   */
 132 #define AK8974_CTRL3_RESDEF     0x00
 133
 134 #define AK8974_INT_CTRL_XEN     BIT(7) /* Enable interrupt for this axis */
 135 #define AK8974_INT_CTRL_YEN     BIT(6)
 136 #define AK8974_INT_CTRL_ZEN     BIT(5)
 137 #define AK8974_INT_CTRL_XYZEN   (BIT(7)|BIT(6)|BIT(5))
 138 #define AK8974_INT_CTRL_POL     BIT(3) /* 0 = active low; 1 = active high */
 139 #define AK8974_INT_CTRL_PULSE   BIT(1) /* 0 = latched; 1 = pulse (50 usec) */
 140 #define AK8974_INT_CTRL_RESDEF  (AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL)
 141
 142 /* The AMI305 has elaborate FW version and serial number registers */
 143 #define AMI305_VER              0xE8
 144 #define AMI305_SN               0xEA
 145
 146 #define AK8974_MAX_RANGE        2048
 147
 148 #define AK8974_POWERON_DELAY    50
 149 #define AK8974_ACTIVATE_DELAY   1
 150 #define AK8974_SELFTEST_DELAY   1
 151 /*
 152  * Set the autosuspend to two orders of magnitude larger than the poweron
 153  * delay to make sane reasonable power tradeoff savings (5 seconds in
 154  * this case).
 155  */
 156 #define AK8974_AUTOSUSPEND_DELAY 5000
 157
 158 #define AK8974_MEASTIME         3
 159
 160 #define AK8974_PWR_ON           1
 161 #define AK8974_PWR_OFF          0
 162
 163 /**
 164  * struct ak8974 - state container for the AK8974 driver
 165  * @i2c: parent I2C client
 166  * @orientation: mounting matrix, flipped axis etc
 167  * @map: regmap to access the AK8974 registers over I2C
 168  * @regs: the avdd and dvdd power regulators
 169  * @name: the name of the part
 170  * @variant: the whoami ID value (for selecting code paths)
 171  * @lock: locks the magnetometer for exclusive use during a measurement
 172  * @drdy_irq: uses the DRDY IRQ line
 173  * @drdy_complete: completion for DRDY
 174  * @drdy_active_low: the DRDY IRQ is active low
 175  */
 176 struct ak8974 {
 177         struct i2c_client *i2c;
 178         struct iio_mount_matrix orientation;
 179         struct regmap *map;
 180         struct regulator_bulk_data regs[2];
 181         const char *name;
 182         u8 variant;
 183         struct mutex lock;
 184         bool drdy_irq;
 185         struct completion drdy_complete;
 186         bool drdy_active_low;
 187 };
 188
 189 static const char ak8974_reg_avdd[] = "avdd";
 190 static const char ak8974_reg_dvdd[] = "dvdd";
 191
 192 static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val)
 193 {
 194         int ret;
 195         __le16 bulk;
 196
 197         ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2);
 198         if (ret)
 199                 return ret;
 200         *val = le16_to_cpu(bulk);
 201
 202         return 0;
 203 }
 204
 205 static int ak8974_set_u16_val(struct ak8974 *ak8974, u8 reg, u16 val)
 206 {
 207         __le16 bulk = cpu_to_le16(val);
 208
 209         return regmap_bulk_write(ak8974->map, reg, &bulk, 2);
 210 }
 211
 212 static int ak8974_set_power(struct ak8974 *ak8974, bool mode)
 213 {
 214         int ret;
 215         u8 val;
 216
 217         val = mode ? AK8974_CTRL1_POWER : 0;
 218         val |= AK8974_CTRL1_FORCE_EN;
 219         ret = regmap_write(ak8974->map, AK8974_CTRL1, val);
 220         if (ret < 0)
 221                 return ret;
 222
 223         if (mode)
 224                 msleep(AK8974_ACTIVATE_DELAY);
 225
 226         return 0;
 227 }
 228
 229 static int ak8974_reset(struct ak8974 *ak8974)
 230 {
 231         int ret;
 232
 233         /* Power on to get register access. Sets CTRL1 reg to reset state */
 234         ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
 235         if (ret)
 236                 return ret;
 237         ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF);
 238         if (ret)
 239                 return ret;
 240         ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF);
 241         if (ret)
 242                 return ret;
 243         ret = regmap_write(ak8974->map, AK8974_INT_CTRL,
 244                            AK8974_INT_CTRL_RESDEF);
 245         if (ret)
 246                 return ret;
 247
 248         /* After reset, power off is default state */
 249         return ak8974_set_power(ak8974, AK8974_PWR_OFF);
 250 }
 251
 252 static int ak8974_configure(struct ak8974 *ak8974)
 253 {
 254         int ret;
 255
 256         ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN |
 257                            AK8974_CTRL2_INT_EN);
 258         if (ret)
 259                 return ret;
 260         ret = regmap_write(ak8974->map, AK8974_CTRL3, 0);
 261         if (ret)
 262                 return ret;
 263         if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI306) {
 264                 /* magic from datasheet: set high-speed measurement mode */
 265                 ret = ak8974_set_u16_val(ak8974, AMI306_CTRL4, 0xA07E);
 266                 if (ret)
 267                         return ret;
 268         }
 269         ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL);
 270         if (ret)
 271                 return ret;
 272
 273         return regmap_write(ak8974->map, AK8974_PRESET, 0);
 274 }
 275
 276 static int ak8974_trigmeas(struct ak8974 *ak8974)
 277 {
 278         unsigned int clear;
 279         u8 mask;
 280         u8 val;
 281         int ret;
 282
 283         /* Clear any previous measurement overflow status */
 284         ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear);
 285         if (ret)
 286                 return ret;
 287
 288         /* If we have a DRDY IRQ line, use it */
 289         if (ak8974->drdy_irq) {
 290                 mask = AK8974_CTRL2_INT_EN |
 291                         AK8974_CTRL2_DRDY_EN |
 292                         AK8974_CTRL2_DRDY_POL;
 293                 val = AK8974_CTRL2_DRDY_EN;
 294
 295                 if (!ak8974->drdy_active_low)
 296                         val |= AK8974_CTRL2_DRDY_POL;
 297
 298                 init_completion(&ak8974->drdy_complete);
 299                 ret = regmap_update_bits(ak8974->map, AK8974_CTRL2,
 300                                          mask, val);
 301                 if (ret)
 302                         return ret;
 303         }
 304
 305         /* Force a measurement */
 306         return regmap_update_bits(ak8974->map,
 307                                   AK8974_CTRL3,
 308                                   AK8974_CTRL3_FORCE,
 309                                   AK8974_CTRL3_FORCE);
 310 }
 311
 312 static int ak8974_await_drdy(struct ak8974 *ak8974)
 313 {
 314         int timeout = 2;
 315         unsigned int val;
 316         int ret;
 317
 318         if (ak8974->drdy_irq) {
 319                 ret = wait_for_completion_timeout(&ak8974->drdy_complete,
 320                                         1 + msecs_to_jiffies(1000));
 321                 if (!ret) {
 322                         dev_err(&ak8974->i2c->dev,
 323                                 "timeout waiting for DRDY IRQ\n");
 324                         return -ETIMEDOUT;
 325                 }
 326                 return 0;
 327         }
 328
 329         /* Default delay-based poll loop */
 330         do {
 331                 msleep(AK8974_MEASTIME);
 332                 ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
 333                 if (ret < 0)
 334                         return ret;
 335                 if (val & AK8974_STATUS_DRDY)
 336                         return 0;
 337         } while (--timeout);
 338
 339         dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n");
 340         return -ETIMEDOUT;
 341 }
 342
 343 static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result)
 344 {
 345         unsigned int src;
 346         int ret;
 347
 348         ret = ak8974_await_drdy(ak8974);
 349         if (ret)
 350                 return ret;
 351         ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src);
 352         if (ret < 0)
 353                 return ret;
 354
 355         /* Out of range overflow! Strong magnet close? */
 356         if (src & AK8974_INT_RANGE) {
 357                 dev_err(&ak8974->i2c->dev,
 358                         "range overflow in sensor\n");
 359                 return -ERANGE;
 360         }
 361
 362         ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6);
 363         if (ret)
 364                 return ret;
 365
 366         return ret;
 367 }
 368
 369 static irqreturn_t ak8974_drdy_irq(int irq, void *d)
 370 {
 371         struct ak8974 *ak8974 = d;
 372
 373         if (!ak8974->drdy_irq)
 374                 return IRQ_NONE;
 375
 376         /* TODO: timestamp here to get good measurement stamps */
 377         return IRQ_WAKE_THREAD;
 378 }
 379
 380 static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d)
 381 {
 382         struct ak8974 *ak8974 = d;
 383         unsigned int val;
 384         int ret;
 385
 386         /* Check if this was a DRDY from us */
 387         ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
 388         if (ret < 0) {
 389                 dev_err(&ak8974->i2c->dev, "error reading DRDY status\n");
 390                 return IRQ_HANDLED;
 391         }
 392         if (val & AK8974_STATUS_DRDY) {
 393                 /* Yes this was our IRQ */
 394                 complete(&ak8974->drdy_complete);
 395                 return IRQ_HANDLED;
 396         }
 397
 398         /* We may be on a shared IRQ, let the next client check */
 399         return IRQ_NONE;
 400 }
 401
 402 static int ak8974_selftest(struct ak8974 *ak8974)
 403 {
 404         struct device *dev = &ak8974->i2c->dev;
 405         unsigned int val;
 406         int ret;
 407
 408         ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
 409         if (ret)
 410                 return ret;
 411         if (val != AK8974_SELFTEST_IDLE) {
 412                 dev_err(dev, "selftest not idle before test\n");
 413                 return -EIO;
 414         }
 415
 416         /* Trigger self-test */
 417         ret = regmap_update_bits(ak8974->map,
 418                         AK8974_CTRL3,
 419                         AK8974_CTRL3_SELFTEST,
 420                         AK8974_CTRL3_SELFTEST);
 421         if (ret) {
 422                 dev_err(dev, "could not write CTRL3\n");
 423                 return ret;
 424         }
 425
 426         msleep(AK8974_SELFTEST_DELAY);
 427
 428         ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
 429         if (ret)
 430                 return ret;
 431         if (val != AK8974_SELFTEST_OK) {
 432                 dev_err(dev, "selftest result NOT OK (%02x)\n", val);
 433                 return -EIO;
 434         }
 435
 436         ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
 437         if (ret)
 438                 return ret;
 439         if (val != AK8974_SELFTEST_IDLE) {
 440                 dev_err(dev, "selftest not idle after test (%02x)\n", val);
 441                 return -EIO;
 442         }
 443         dev_dbg(dev, "passed self-test\n");
 444
 445         return 0;
 446 }
 447
 448 static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg,
 449                                    __le16 *tab, size_t tab_size)
 450 {
 451         int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size);
 452         if (ret) {
 453                 memset(tab, 0xFF, tab_size);
 454                 dev_warn(&ak8974->i2c->dev,
 455                          "can't read calibration data (regs %u..%zu): %d\n",
 456                          reg, reg + tab_size - 1, ret);
 457         } else {
 458                 add_device_randomness(tab, tab_size);
 459         }
 460 }
 461
 462 static int ak8974_detect(struct ak8974 *ak8974)
 463 {
 464         unsigned int whoami;
 465         const char *name;
 466         int ret;
 467         unsigned int fw;
 468         u16 sn;
 469
 470         ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami);
 471         if (ret)
 472                 return ret;
 473
 474         name = "ami305";
 475
 476         switch (whoami) {
 477         case AK8974_WHOAMI_VALUE_AMI306:
 478                 name = "ami306";
 479                 /* fall-through */
 480         case AK8974_WHOAMI_VALUE_AMI305:
 481                 ret = regmap_read(ak8974->map, AMI305_VER, &fw);
 482                 if (ret)
 483                         return ret;
 484                 fw &= 0x7f; /* only bits 0 thru 6 valid */
 485                 ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn);
 486                 if (ret)
 487                         return ret;
 488                 add_device_randomness(&sn, sizeof(sn));
 489                 dev_info(&ak8974->i2c->dev,
 490                          "detected %s, FW ver %02x, S/N: %04x\n",
 491                          name, fw, sn);
 492                 break;
 493         case AK8974_WHOAMI_VALUE_AK8974:
 494                 name = "ak8974";
 495                 dev_info(&ak8974->i2c->dev, "detected AK8974\n");
 496                 break;
 497         default:
 498                 dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ",
 499                         whoami);
 500                 return -ENODEV;
 501         }
 502
 503         ak8974->name = name;
 504         ak8974->variant = whoami;
 505
 506         if (whoami == AK8974_WHOAMI_VALUE_AMI306) {
 507                 __le16 fab_data1[9], fab_data2[3];
 508                 int i;
 509
 510                 ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X,
 511                                        fab_data1, sizeof(fab_data1));
 512                 ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X,
 513                                        fab_data2, sizeof(fab_data2));
 514
 515                 for (i = 0; i < 3; ++i) {
 516                         static const char axis[3] = "XYZ";
 517                         static const char pgaxis[6] = "ZYZXYX";
 518                         unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F;
 519                         unsigned fine = le16_to_cpu(fab_data1[i]);
 520                         unsigned sens = le16_to_cpu(fab_data1[i + 3]);
 521                         unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]);
 522                         unsigned pgain2 = pgain1 >> 8;
 523
 524                         pgain1 &= 0xFF;
 525
 526                         dev_info(&ak8974->i2c->dev,
 527                                  "factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n",
 528                                  axis[i], offz, sens, fine, pgaxis[i * 2],
 529                                  pgain1, pgaxis[i * 2 + 1], pgain2);
 530                 }
 531         }
 532
 533         return 0;
 534 }
 535
 536 static int ak8974_read_raw(struct iio_dev *indio_dev,
 537                            struct iio_chan_spec const *chan,
 538                            int *val, int *val2,
 539                            long mask)
 540 {
 541         struct ak8974 *ak8974 = iio_priv(indio_dev);
 542         __le16 hw_values[3];
 543         int ret = -EINVAL;
 544
 545         pm_runtime_get_sync(&ak8974->i2c->dev);
 546         mutex_lock(&ak8974->lock);
 547
 548         switch (mask) {
 549         case IIO_CHAN_INFO_RAW:
 550                 if (chan->address > 2) {
 551                         dev_err(&ak8974->i2c->dev, "faulty channel address\n");
 552                         ret = -EIO;
 553                         goto out_unlock;
 554                 }
 555                 ret = ak8974_trigmeas(ak8974);
 556                 if (ret)
 557                         goto out_unlock;
 558                 ret = ak8974_getresult(ak8974, hw_values);
 559                 if (ret)
 560                         goto out_unlock;
 561
 562                 /*
 563                  * We read all axes and discard all but one, for optimized
 564                  * reading, use the triggered buffer.
 565                  */
 566                 *val = le16_to_cpu(hw_values[chan->address]);
 567
 568                 ret = IIO_VAL_INT;
 569         }
 570
 571  out_unlock:
 572         mutex_unlock(&ak8974->lock);
 573         pm_runtime_mark_last_busy(&ak8974->i2c->dev);
 574         pm_runtime_put_autosuspend(&ak8974->i2c->dev);
 575
 576         return ret;
 577 }
 578
 579 static void ak8974_fill_buffer(struct iio_dev *indio_dev)
 580 {
 581         struct ak8974 *ak8974 = iio_priv(indio_dev);
 582         int ret;
 583         __le16 hw_values[8]; /* Three axes + 64bit padding */
 584
 585         pm_runtime_get_sync(&ak8974->i2c->dev);
 586         mutex_lock(&ak8974->lock);
 587
 588         ret = ak8974_trigmeas(ak8974);
 589         if (ret) {
 590                 dev_err(&ak8974->i2c->dev, "error triggering measure\n");
 591                 goto out_unlock;
 592         }
 593         ret = ak8974_getresult(ak8974, hw_values);
 594         if (ret) {
 595                 dev_err(&ak8974->i2c->dev, "error getting measures\n");
 596                 goto out_unlock;
 597         }
 598
 599         iio_push_to_buffers_with_timestamp(indio_dev, hw_values,
 600                                            iio_get_time_ns(indio_dev));
 601
 602  out_unlock:
 603         mutex_unlock(&ak8974->lock);
 604         pm_runtime_mark_last_busy(&ak8974->i2c->dev);
 605         pm_runtime_put_autosuspend(&ak8974->i2c->dev);
 606 }
 607
 608 static irqreturn_t ak8974_handle_trigger(int irq, void *p)
 609 {
 610         const struct iio_poll_func *pf = p;
 611         struct iio_dev *indio_dev = pf->indio_dev;
 612
 613         ak8974_fill_buffer(indio_dev);
 614         iio_trigger_notify_done(indio_dev->trig);
 615
 616         return IRQ_HANDLED;
 617 }
 618
 619 static const struct iio_mount_matrix *
 620 ak8974_get_mount_matrix(const struct iio_dev *indio_dev,
 621                         const struct iio_chan_spec *chan)
 622 {
 623         struct ak8974 *ak8974 = iio_priv(indio_dev);
 624
 625         return &ak8974->orientation;
 626 }
 627
 628 static const struct iio_chan_spec_ext_info ak8974_ext_info[] = {
 629         IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix),
 630         { },
 631 };
 632
 633 #define AK8974_AXIS_CHANNEL(axis, index)                                \
 634         {                                                               \
 635                 .type = IIO_MAGN,                                       \
 636                 .modified = 1,                                          \
 637                 .channel2 = IIO_MOD_##axis,                             \
 638                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
 639                 .ext_info = ak8974_ext_info,                            \
 640                 .address = index,                                       \
 641                 .scan_index = index,                                    \
 642                 .scan_type = {                                          \
 643                         .sign = 's',                                    \
 644                         .realbits = 16,                                 \
 645                         .storagebits = 16,                              \
 646                         .endianness = IIO_LE                            \
 647                 },                                                      \
 648         }
 649
 650 static const struct iio_chan_spec ak8974_channels[] = {
 651         AK8974_AXIS_CHANNEL(X, 0),
 652         AK8974_AXIS_CHANNEL(Y, 1),
 653         AK8974_AXIS_CHANNEL(Z, 2),
 654         IIO_CHAN_SOFT_TIMESTAMP(3),
 655 };
 656
 657 static const unsigned long ak8974_scan_masks[] = { 0x7, 0 };
 658
 659 static const struct iio_info ak8974_info = {
 660         .read_raw = &ak8974_read_raw,
 661 };
 662
 663 static bool ak8974_writeable_reg(struct device *dev, unsigned int reg)
 664 {
 665         struct i2c_client *i2c = to_i2c_client(dev);
 666         struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
 667         struct ak8974 *ak8974 = iio_priv(indio_dev);
 668
 669         switch (reg) {
 670         case AK8974_CTRL1:
 671         case AK8974_CTRL2:
 672         case AK8974_CTRL3:
 673         case AK8974_INT_CTRL:
 674         case AK8974_INT_THRES:
 675         case AK8974_INT_THRES + 1:
 676         case AK8974_PRESET:
 677         case AK8974_PRESET + 1:
 678                 return true;
 679         case AK8974_OFFSET_X:
 680         case AK8974_OFFSET_X + 1:
 681         case AK8974_OFFSET_Y:
 682         case AK8974_OFFSET_Y + 1:
 683         case AK8974_OFFSET_Z:
 684         case AK8974_OFFSET_Z + 1:
 685                 if (ak8974->variant == AK8974_WHOAMI_VALUE_AK8974)
 686                         return true;
 687                 return false;
 688         case AMI305_OFFSET_X:
 689         case AMI305_OFFSET_X + 1:
 690         case AMI305_OFFSET_Y:
 691         case AMI305_OFFSET_Y + 1:
 692         case AMI305_OFFSET_Z:
 693         case AMI305_OFFSET_Z + 1:
 694                 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 ||
 695                        ak8974->variant == AK8974_WHOAMI_VALUE_AMI306;
 696         case AMI306_CTRL4:
 697         case AMI306_CTRL4 + 1:
 698                 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306;
 699         default:
 700                 return false;
 701         }
 702 }
 703
 704 static bool ak8974_precious_reg(struct device *dev, unsigned int reg)
 705 {
 706         return reg == AK8974_INT_CLEAR;
 707 }
 708
 709 static const struct regmap_config ak8974_regmap_config = {
 710         .reg_bits = 8,
 711         .val_bits = 8,
 712         .max_register = 0xff,
 713         .writeable_reg = ak8974_writeable_reg,
 714         .precious_reg = ak8974_precious_reg,
 715 };
 716
 717 static int ak8974_probe(struct i2c_client *i2c,
 718                         const struct i2c_device_id *id)
 719 {
 720         struct iio_dev *indio_dev;
 721         struct ak8974 *ak8974;
 722         unsigned long irq_trig;
 723         int irq = i2c->irq;
 724         int ret;
 725
 726         /* Register with IIO */
 727         indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974));
 728         if (indio_dev == NULL)
 729                 return -ENOMEM;
 730
 731         ak8974 = iio_priv(indio_dev);
 732         i2c_set_clientdata(i2c, indio_dev);
 733         ak8974->i2c = i2c;
 734         mutex_init(&ak8974->lock);
 735
 736         ret = of_iio_read_mount_matrix(&i2c->dev,
 737                                        "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");