linux/drivers/iio/magnetometer/ak8974.c
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   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 */
 176struct 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
 189static const char ak8974_reg_avdd[] = "avdd";
 190static const char ak8974_reg_dvdd[] = "dvdd";
 191
 192static 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
 205static 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
 212static 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
 229static 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
 252static 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
 276static 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
 312static 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
 343static 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
 369static 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
 380static 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
 402static 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
 448static 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
 462static 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
 536static 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
 579static 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
 608static 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
 619static const struct iio_mount_matrix *
 620ak8974_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
 628static 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
 650static 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
 657static const unsigned long ak8974_scan_masks[] = { 0x7, 0 };
 658
 659static const struct iio_info ak8974_info = {
 660        .read_raw = &ak8974_read_raw,
 661};
 662
 663static 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
 704static bool ak8974_precious_reg(struct device *dev, unsigned int reg)
 705{
 706        return reg == AK8974_INT_CLEAR;
 707}
 708
 709static 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
 717static 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
 842no_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
 851cleanup_buffer:
 852        iio_triggered_buffer_cleanup(indio_dev);
 853disable_pm:
 854        pm_runtime_put_noidle(&i2c->dev);
 855        pm_runtime_disable(&i2c->dev);
 856        ak8974_set_power(ak8974, AK8974_PWR_OFF);
 857power_off:
 858        regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
 859
 860        return ret;
 861}
 862
 863static 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
 879static 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
 890static 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
 910out_disable_power:
 911        ak8974_set_power(ak8974, AK8974_PWR_OFF);
 912out_regulator_disable:
 913        regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
 914
 915        return ret;
 916}
 917
 918static 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
 925static const struct i2c_device_id ak8974_id[] = {
 926        {"ami305", 0 },
 927        {"ami306", 0 },
 928        {"ak8974", 0 },
 929        {}
 930};
 931MODULE_DEVICE_TABLE(i2c, ak8974_id);
 932
 933static const struct of_device_id ak8974_of_match[] = {
 934        { .compatible = "asahi-kasei,ak8974", },
 935        {}
 936};
 937MODULE_DEVICE_TABLE(of, ak8974_of_match);
 938
 939static 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};
 949module_i2c_driver(ak8974_driver);
 950
 951MODULE_DESCRIPTION("AK8974 and AMI30x 3-axis magnetometer driver");
 952MODULE_AUTHOR("Samu Onkalo");
 953MODULE_AUTHOR("Linus Walleij");
 954MODULE_LICENSE("GPL v2");
 955