linux/drivers/iio/accel/mxc4005.c
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   1/*
   2 * 3-axis accelerometer driver for MXC4005XC Memsic sensor
   3 *
   4 * Copyright (c) 2014, Intel Corporation.
   5 *
   6 * This program is free software; you can redistribute it and/or modify it
   7 * under the terms and conditions of the GNU General Public License,
   8 * version 2, as published by the Free Software Foundation.
   9 *
  10 * This program is distributed in the hope it will be useful, but WITHOUT
  11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13 * more details.
  14 */
  15
  16#include <linux/module.h>
  17#include <linux/i2c.h>
  18#include <linux/iio/iio.h>
  19#include <linux/acpi.h>
  20#include <linux/regmap.h>
  21#include <linux/iio/sysfs.h>
  22#include <linux/iio/trigger.h>
  23#include <linux/iio/buffer.h>
  24#include <linux/iio/triggered_buffer.h>
  25#include <linux/iio/trigger_consumer.h>
  26
  27#define MXC4005_DRV_NAME                "mxc4005"
  28#define MXC4005_IRQ_NAME                "mxc4005_event"
  29#define MXC4005_REGMAP_NAME             "mxc4005_regmap"
  30
  31#define MXC4005_REG_XOUT_UPPER          0x03
  32#define MXC4005_REG_XOUT_LOWER          0x04
  33#define MXC4005_REG_YOUT_UPPER          0x05
  34#define MXC4005_REG_YOUT_LOWER          0x06
  35#define MXC4005_REG_ZOUT_UPPER          0x07
  36#define MXC4005_REG_ZOUT_LOWER          0x08
  37
  38#define MXC4005_REG_INT_MASK1           0x0B
  39#define MXC4005_REG_INT_MASK1_BIT_DRDYE 0x01
  40
  41#define MXC4005_REG_INT_CLR1            0x01
  42#define MXC4005_REG_INT_CLR1_BIT_DRDYC  0x01
  43
  44#define MXC4005_REG_CONTROL             0x0D
  45#define MXC4005_REG_CONTROL_MASK_FSR    GENMASK(6, 5)
  46#define MXC4005_CONTROL_FSR_SHIFT       5
  47
  48#define MXC4005_REG_DEVICE_ID           0x0E
  49
  50enum mxc4005_axis {
  51        AXIS_X,
  52        AXIS_Y,
  53        AXIS_Z,
  54};
  55
  56enum mxc4005_range {
  57        MXC4005_RANGE_2G,
  58        MXC4005_RANGE_4G,
  59        MXC4005_RANGE_8G,
  60};
  61
  62struct mxc4005_data {
  63        struct device *dev;
  64        struct mutex mutex;
  65        struct regmap *regmap;
  66        struct iio_trigger *dready_trig;
  67        __be16 buffer[8];
  68        bool trigger_enabled;
  69};
  70
  71/*
  72 * MXC4005 can operate in the following ranges:
  73 * +/- 2G, 4G, 8G (the default +/-2G)
  74 *
  75 * (2 + 2) * 9.81 / (2^12 - 1) = 0.009582
  76 * (4 + 4) * 9.81 / (2^12 - 1) = 0.019164
  77 * (8 + 8) * 9.81 / (2^12 - 1) = 0.038329
  78 */
  79static const struct {
  80        u8 range;
  81        int scale;
  82} mxc4005_scale_table[] = {
  83        {MXC4005_RANGE_2G, 9582},
  84        {MXC4005_RANGE_4G, 19164},
  85        {MXC4005_RANGE_8G, 38329},
  86};
  87
  88
  89static IIO_CONST_ATTR(in_accel_scale_available, "0.009582 0.019164 0.038329");
  90
  91static struct attribute *mxc4005_attributes[] = {
  92        &iio_const_attr_in_accel_scale_available.dev_attr.attr,
  93        NULL,
  94};
  95
  96static const struct attribute_group mxc4005_attrs_group = {
  97        .attrs = mxc4005_attributes,
  98};
  99
 100static bool mxc4005_is_readable_reg(struct device *dev, unsigned int reg)
 101{
 102        switch (reg) {
 103        case MXC4005_REG_XOUT_UPPER:
 104        case MXC4005_REG_XOUT_LOWER:
 105        case MXC4005_REG_YOUT_UPPER:
 106        case MXC4005_REG_YOUT_LOWER:
 107        case MXC4005_REG_ZOUT_UPPER:
 108        case MXC4005_REG_ZOUT_LOWER:
 109        case MXC4005_REG_DEVICE_ID:
 110        case MXC4005_REG_CONTROL:
 111                return true;
 112        default:
 113                return false;
 114        }
 115}
 116
 117static bool mxc4005_is_writeable_reg(struct device *dev, unsigned int reg)
 118{
 119        switch (reg) {
 120        case MXC4005_REG_INT_CLR1:
 121        case MXC4005_REG_INT_MASK1:
 122        case MXC4005_REG_CONTROL:
 123                return true;
 124        default:
 125                return false;
 126        }
 127}
 128
 129static const struct regmap_config mxc4005_regmap_config = {
 130        .name = MXC4005_REGMAP_NAME,
 131
 132        .reg_bits = 8,
 133        .val_bits = 8,
 134
 135        .max_register = MXC4005_REG_DEVICE_ID,
 136
 137        .readable_reg = mxc4005_is_readable_reg,
 138        .writeable_reg = mxc4005_is_writeable_reg,
 139};
 140
 141static int mxc4005_read_xyz(struct mxc4005_data *data)
 142{
 143        int ret;
 144
 145        ret = regmap_bulk_read(data->regmap, MXC4005_REG_XOUT_UPPER,
 146                               (u8 *) data->buffer, sizeof(data->buffer));
 147        if (ret < 0) {
 148                dev_err(data->dev, "failed to read axes\n");
 149                return ret;
 150        }
 151
 152        return 0;
 153}
 154
 155static int mxc4005_read_axis(struct mxc4005_data *data,
 156                             unsigned int addr)
 157{
 158        __be16 reg;
 159        int ret;
 160
 161        ret = regmap_bulk_read(data->regmap, addr, (u8 *) &reg, sizeof(reg));
 162        if (ret < 0) {
 163                dev_err(data->dev, "failed to read reg %02x\n", addr);
 164                return ret;
 165        }
 166
 167        return be16_to_cpu(reg);
 168}
 169
 170static int mxc4005_read_scale(struct mxc4005_data *data)
 171{
 172        unsigned int reg;
 173        int ret;
 174        int i;
 175
 176        ret = regmap_read(data->regmap, MXC4005_REG_CONTROL, &reg);
 177        if (ret < 0) {
 178                dev_err(data->dev, "failed to read reg_control\n");
 179                return ret;
 180        }
 181
 182        i = reg >> MXC4005_CONTROL_FSR_SHIFT;
 183
 184        if (i < 0 || i >= ARRAY_SIZE(mxc4005_scale_table))
 185                return -EINVAL;
 186
 187        return mxc4005_scale_table[i].scale;
 188}
 189
 190static int mxc4005_set_scale(struct mxc4005_data *data, int val)
 191{
 192        unsigned int reg;
 193        int i;
 194        int ret;
 195
 196        for (i = 0; i < ARRAY_SIZE(mxc4005_scale_table); i++) {
 197                if (mxc4005_scale_table[i].scale == val) {
 198                        reg = i << MXC4005_CONTROL_FSR_SHIFT;
 199                        ret = regmap_update_bits(data->regmap,
 200                                                 MXC4005_REG_CONTROL,
 201                                                 MXC4005_REG_CONTROL_MASK_FSR,
 202                                                 reg);
 203                        if (ret < 0)
 204                                dev_err(data->dev,
 205                                        "failed to write reg_control\n");
 206                        return ret;
 207                }
 208        }
 209
 210        return -EINVAL;
 211}
 212
 213static int mxc4005_read_raw(struct iio_dev *indio_dev,
 214                            struct iio_chan_spec const *chan,
 215                            int *val, int *val2, long mask)
 216{
 217        struct mxc4005_data *data = iio_priv(indio_dev);
 218        int ret;
 219
 220        switch (mask) {
 221        case IIO_CHAN_INFO_RAW:
 222                switch (chan->type) {
 223                case IIO_ACCEL:
 224                        if (iio_buffer_enabled(indio_dev))
 225                                return -EBUSY;
 226
 227                        ret = mxc4005_read_axis(data, chan->address);
 228                        if (ret < 0)
 229                                return ret;
 230                        *val = sign_extend32(ret >> chan->scan_type.shift,
 231                                             chan->scan_type.realbits - 1);
 232                        return IIO_VAL_INT;
 233                default:
 234                        return -EINVAL;
 235                }
 236        case IIO_CHAN_INFO_SCALE:
 237                ret = mxc4005_read_scale(data);
 238                if (ret < 0)
 239                        return ret;
 240
 241                *val = 0;
 242                *val2 = ret;
 243                return IIO_VAL_INT_PLUS_MICRO;
 244        default:
 245                return -EINVAL;
 246        }
 247}
 248
 249static int mxc4005_write_raw(struct iio_dev *indio_dev,
 250                             struct iio_chan_spec const *chan,
 251                             int val, int val2, long mask)
 252{
 253        struct mxc4005_data *data = iio_priv(indio_dev);
 254
 255        switch (mask) {
 256        case IIO_CHAN_INFO_SCALE:
 257                if (val != 0)
 258                        return -EINVAL;
 259
 260                return mxc4005_set_scale(data, val2);
 261        default:
 262                return -EINVAL;
 263        }
 264}
 265
 266static const struct iio_info mxc4005_info = {
 267        .driver_module  = THIS_MODULE,
 268        .read_raw       = mxc4005_read_raw,
 269        .write_raw      = mxc4005_write_raw,
 270        .attrs          = &mxc4005_attrs_group,
 271};
 272
 273static const unsigned long mxc4005_scan_masks[] = {
 274        BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
 275        0
 276};
 277
 278#define MXC4005_CHANNEL(_axis, _addr) {                         \
 279        .type = IIO_ACCEL,                                      \
 280        .modified = 1,                                          \
 281        .channel2 = IIO_MOD_##_axis,                            \
 282        .address = _addr,                                       \
 283        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
 284        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
 285        .scan_index = AXIS_##_axis,                             \
 286        .scan_type = {                                          \
 287                .sign = 's',                                    \
 288                .realbits = 12,                                 \
 289                .storagebits = 16,                              \
 290                .shift = 4,                                     \
 291                .endianness = IIO_BE,                           \
 292        },                                                      \
 293}
 294
 295static const struct iio_chan_spec mxc4005_channels[] = {
 296        MXC4005_CHANNEL(X, MXC4005_REG_XOUT_UPPER),
 297        MXC4005_CHANNEL(Y, MXC4005_REG_YOUT_UPPER),
 298        MXC4005_CHANNEL(Z, MXC4005_REG_ZOUT_UPPER),
 299        IIO_CHAN_SOFT_TIMESTAMP(3),
 300};
 301
 302static irqreturn_t mxc4005_trigger_handler(int irq, void *private)
 303{
 304        struct iio_poll_func *pf = private;
 305        struct iio_dev *indio_dev = pf->indio_dev;
 306        struct mxc4005_data *data = iio_priv(indio_dev);
 307        int ret;
 308
 309        ret = mxc4005_read_xyz(data);
 310        if (ret < 0)
 311                goto err;
 312
 313        iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
 314                                           pf->timestamp);
 315
 316err:
 317        iio_trigger_notify_done(indio_dev->trig);
 318
 319        return IRQ_HANDLED;
 320}
 321
 322static int mxc4005_clr_intr(struct mxc4005_data *data)
 323{
 324        int ret;
 325
 326        /* clear interrupt */
 327        ret = regmap_write(data->regmap, MXC4005_REG_INT_CLR1,
 328                           MXC4005_REG_INT_CLR1_BIT_DRDYC);
 329        if (ret < 0) {
 330                dev_err(data->dev, "failed to write to reg_int_clr1\n");
 331                return ret;
 332        }
 333
 334        return 0;
 335}
 336
 337static int mxc4005_set_trigger_state(struct iio_trigger *trig,
 338                                     bool state)
 339{
 340        struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 341        struct mxc4005_data *data = iio_priv(indio_dev);
 342        int ret;
 343
 344        mutex_lock(&data->mutex);
 345        if (state) {
 346                ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK1,
 347                                   MXC4005_REG_INT_MASK1_BIT_DRDYE);
 348        } else {
 349                ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK1,
 350                                   ~MXC4005_REG_INT_MASK1_BIT_DRDYE);
 351        }
 352
 353        if (ret < 0) {
 354                mutex_unlock(&data->mutex);
 355                dev_err(data->dev, "failed to update reg_int_mask1");
 356                return ret;
 357        }
 358
 359        data->trigger_enabled = state;
 360        mutex_unlock(&data->mutex);
 361
 362        return 0;
 363}
 364
 365static int mxc4005_trigger_try_reen(struct iio_trigger *trig)
 366{
 367        struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 368        struct mxc4005_data *data = iio_priv(indio_dev);
 369
 370        if (!data->dready_trig)
 371                return 0;
 372
 373        return mxc4005_clr_intr(data);
 374}
 375
 376static const struct iio_trigger_ops mxc4005_trigger_ops = {
 377        .set_trigger_state = mxc4005_set_trigger_state,
 378        .try_reenable = mxc4005_trigger_try_reen,
 379        .owner = THIS_MODULE,
 380};
 381
 382static int mxc4005_chip_init(struct mxc4005_data *data)
 383{
 384        int ret;
 385        unsigned int reg;
 386
 387        ret = regmap_read(data->regmap, MXC4005_REG_DEVICE_ID, &reg);
 388        if (ret < 0) {
 389                dev_err(data->dev, "failed to read chip id\n");
 390                return ret;
 391        }
 392
 393        dev_dbg(data->dev, "MXC4005 chip id %02x\n", reg);
 394
 395        return 0;
 396}
 397
 398static int mxc4005_probe(struct i2c_client *client,
 399                         const struct i2c_device_id *id)
 400{
 401        struct mxc4005_data *data;
 402        struct iio_dev *indio_dev;
 403        struct regmap *regmap;
 404        int ret;
 405
 406        indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 407        if (!indio_dev)
 408                return -ENOMEM;
 409
 410        regmap = devm_regmap_init_i2c(client, &mxc4005_regmap_config);
 411        if (IS_ERR(regmap)) {
 412                dev_err(&client->dev, "failed to initialize regmap\n");
 413                return PTR_ERR(regmap);
 414        }
 415
 416        data = iio_priv(indio_dev);
 417        i2c_set_clientdata(client, indio_dev);
 418        data->dev = &client->dev;
 419        data->regmap = regmap;
 420
 421        ret = mxc4005_chip_init(data);
 422        if (ret < 0) {
 423                dev_err(&client->dev, "failed to initialize chip\n");
 424                return ret;
 425        }
 426
 427        mutex_init(&data->mutex);
 428
 429        indio_dev->dev.parent = &client->dev;
 430        indio_dev->channels = mxc4005_channels;
 431        indio_dev->num_channels = ARRAY_SIZE(mxc4005_channels);
 432        indio_dev->available_scan_masks = mxc4005_scan_masks;
 433        indio_dev->name = MXC4005_DRV_NAME;
 434        indio_dev->modes = INDIO_DIRECT_MODE;
 435        indio_dev->info = &mxc4005_info;
 436
 437        ret = iio_triggered_buffer_setup(indio_dev,
 438                                         iio_pollfunc_store_time,
 439                                         mxc4005_trigger_handler,
 440                                         NULL);
 441        if (ret < 0) {
 442                dev_err(&client->dev,
 443                        "failed to setup iio triggered buffer\n");
 444                return ret;
 445        }
 446
 447        if (client->irq > 0) {
 448                data->dready_trig = devm_iio_trigger_alloc(&client->dev,
 449                                                           "%s-dev%d",
 450                                                           indio_dev->name,
 451                                                           indio_dev->id);
 452                if (!data->dready_trig)
 453                        return -ENOMEM;
 454
 455                ret = devm_request_threaded_irq(&client->dev, client->irq,
 456                                                iio_trigger_generic_data_rdy_poll,
 457                                                NULL,
 458                                                IRQF_TRIGGER_FALLING |
 459                                                IRQF_ONESHOT,
 460                                                MXC4005_IRQ_NAME,
 461                                                data->dready_trig);
 462                if (ret) {
 463                        dev_err(&client->dev,
 464                                "failed to init threaded irq\n");
 465                        goto err_buffer_cleanup;
 466                }
 467
 468                data->dready_trig->dev.parent = &client->dev;
 469                data->dready_trig->ops = &mxc4005_trigger_ops;
 470                iio_trigger_set_drvdata(data->dready_trig, indio_dev);
 471                indio_dev->trig = data->dready_trig;
 472                iio_trigger_get(indio_dev->trig);
 473                ret = iio_trigger_register(data->dready_trig);
 474                if (ret) {
 475                        dev_err(&client->dev,
 476                                "failed to register trigger\n");
 477                        goto err_trigger_unregister;
 478                }
 479        }
 480
 481        ret = iio_device_register(indio_dev);
 482        if (ret < 0) {
 483                dev_err(&client->dev,
 484                        "unable to register iio device %d\n", ret);
 485                goto err_buffer_cleanup;
 486        }
 487
 488        return 0;
 489
 490err_trigger_unregister:
 491        iio_trigger_unregister(data->dready_trig);
 492err_buffer_cleanup:
 493        iio_triggered_buffer_cleanup(indio_dev);
 494
 495        return ret;
 496}
 497
 498static int mxc4005_remove(struct i2c_client *client)
 499{
 500        struct iio_dev *indio_dev = i2c_get_clientdata(client);
 501        struct mxc4005_data *data = iio_priv(indio_dev);
 502
 503        iio_device_unregister(indio_dev);
 504
 505        iio_triggered_buffer_cleanup(indio_dev);
 506        if (data->dready_trig)
 507                iio_trigger_unregister(data->dready_trig);
 508
 509        return 0;
 510}
 511
 512static const struct acpi_device_id mxc4005_acpi_match[] = {
 513        {"MXC4005",     0},
 514        { },
 515};
 516MODULE_DEVICE_TABLE(acpi, mxc4005_acpi_match);
 517
 518static const struct i2c_device_id mxc4005_id[] = {
 519        {"mxc4005",     0},
 520        { },
 521};
 522MODULE_DEVICE_TABLE(i2c, mxc4005_id);
 523
 524static struct i2c_driver mxc4005_driver = {
 525        .driver = {
 526                .name = MXC4005_DRV_NAME,
 527                .acpi_match_table = ACPI_PTR(mxc4005_acpi_match),
 528        },
 529        .probe          = mxc4005_probe,
 530        .remove         = mxc4005_remove,
 531        .id_table       = mxc4005_id,
 532};
 533
 534module_i2c_driver(mxc4005_driver);
 535
 536MODULE_AUTHOR("Teodora Baluta <teodora.baluta@intel.com>");
 537MODULE_LICENSE("GPL v2");
 538MODULE_DESCRIPTION("MXC4005 3-axis accelerometer driver");
 539