linux/drivers/iio/accel/kxsd9.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * kxsd9.c      simple support for the Kionix KXSD9 3D
   4 *              accelerometer.
   5 *
   6 * Copyright (c) 2008-2009 Jonathan Cameron <jic23@kernel.org>
   7 *
   8 * The i2c interface is very similar, so shouldn't be a problem once
   9 * I have a suitable wire made up.
  10 *
  11 * TODO:        Support the motion detector
  12 */
  13
  14#include <linux/device.h>
  15#include <linux/kernel.h>
  16#include <linux/sysfs.h>
  17#include <linux/slab.h>
  18#include <linux/module.h>
  19#include <linux/regmap.h>
  20#include <linux/bitops.h>
  21#include <linux/delay.h>
  22#include <linux/regulator/consumer.h>
  23#include <linux/pm_runtime.h>
  24#include <linux/iio/iio.h>
  25#include <linux/iio/sysfs.h>
  26#include <linux/iio/buffer.h>
  27#include <linux/iio/triggered_buffer.h>
  28#include <linux/iio/trigger_consumer.h>
  29
  30#include "kxsd9.h"
  31
  32#define KXSD9_REG_X             0x00
  33#define KXSD9_REG_Y             0x02
  34#define KXSD9_REG_Z             0x04
  35#define KXSD9_REG_AUX           0x06
  36#define KXSD9_REG_RESET         0x0a
  37#define KXSD9_REG_CTRL_C        0x0c
  38
  39#define KXSD9_CTRL_C_FS_MASK    0x03
  40#define KXSD9_CTRL_C_FS_8G      0x00
  41#define KXSD9_CTRL_C_FS_6G      0x01
  42#define KXSD9_CTRL_C_FS_4G      0x02
  43#define KXSD9_CTRL_C_FS_2G      0x03
  44#define KXSD9_CTRL_C_MOT_LAT    BIT(3)
  45#define KXSD9_CTRL_C_MOT_LEV    BIT(4)
  46#define KXSD9_CTRL_C_LP_MASK    0xe0
  47#define KXSD9_CTRL_C_LP_NONE    0x00
  48#define KXSD9_CTRL_C_LP_2000HZC BIT(5)
  49#define KXSD9_CTRL_C_LP_2000HZB BIT(6)
  50#define KXSD9_CTRL_C_LP_2000HZA (BIT(5)|BIT(6))
  51#define KXSD9_CTRL_C_LP_1000HZ  BIT(7)
  52#define KXSD9_CTRL_C_LP_500HZ   (BIT(7)|BIT(5))
  53#define KXSD9_CTRL_C_LP_100HZ   (BIT(7)|BIT(6))
  54#define KXSD9_CTRL_C_LP_50HZ    (BIT(7)|BIT(6)|BIT(5))
  55
  56#define KXSD9_REG_CTRL_B        0x0d
  57
  58#define KXSD9_CTRL_B_CLK_HLD    BIT(7)
  59#define KXSD9_CTRL_B_ENABLE     BIT(6)
  60#define KXSD9_CTRL_B_ST         BIT(5) /* Self-test */
  61
  62#define KXSD9_REG_CTRL_A        0x0e
  63
  64/**
  65 * struct kxsd9_state - device related storage
  66 * @dev: pointer to the parent device
  67 * @map: regmap to the device
  68 * @orientation: mounting matrix, flipped axis etc
  69 * @regs: regulators for this device, VDD and IOVDD
  70 * @scale: the current scaling setting
  71 */
  72struct kxsd9_state {
  73        struct device *dev;
  74        struct regmap *map;
  75        struct iio_mount_matrix orientation;
  76        struct regulator_bulk_data regs[2];
  77        u8 scale;
  78};
  79
  80#define KXSD9_SCALE_2G "0.011978"
  81#define KXSD9_SCALE_4G "0.023927"
  82#define KXSD9_SCALE_6G "0.035934"
  83#define KXSD9_SCALE_8G "0.047853"
  84
  85/* reverse order */
  86static const int kxsd9_micro_scales[4] = { 47853, 35934, 23927, 11978 };
  87
  88#define KXSD9_ZERO_G_OFFSET -2048
  89
  90/*
  91 * Regulator names
  92 */
  93static const char kxsd9_reg_vdd[] = "vdd";
  94static const char kxsd9_reg_iovdd[] = "iovdd";
  95
  96static int kxsd9_write_scale(struct iio_dev *indio_dev, int micro)
  97{
  98        int ret, i;
  99        struct kxsd9_state *st = iio_priv(indio_dev);
 100        bool foundit = false;
 101
 102        for (i = 0; i < 4; i++)
 103                if (micro == kxsd9_micro_scales[i]) {
 104                        foundit = true;
 105                        break;
 106                }
 107        if (!foundit)
 108                return -EINVAL;
 109
 110        ret = regmap_update_bits(st->map,
 111                                 KXSD9_REG_CTRL_C,
 112                                 KXSD9_CTRL_C_FS_MASK,
 113                                 i);
 114        if (ret < 0)
 115                goto error_ret;
 116
 117        /* Cached scale when the sensor is powered down */
 118        st->scale = i;
 119
 120error_ret:
 121        return ret;
 122}
 123
 124static IIO_CONST_ATTR(accel_scale_available,
 125                KXSD9_SCALE_2G " "
 126                KXSD9_SCALE_4G " "
 127                KXSD9_SCALE_6G " "
 128                KXSD9_SCALE_8G);
 129
 130static struct attribute *kxsd9_attributes[] = {
 131        &iio_const_attr_accel_scale_available.dev_attr.attr,
 132        NULL,
 133};
 134
 135static int kxsd9_write_raw(struct iio_dev *indio_dev,
 136                           struct iio_chan_spec const *chan,
 137                           int val,
 138                           int val2,
 139                           long mask)
 140{
 141        int ret = -EINVAL;
 142        struct kxsd9_state *st = iio_priv(indio_dev);
 143
 144        pm_runtime_get_sync(st->dev);
 145
 146        if (mask == IIO_CHAN_INFO_SCALE) {
 147                /* Check no integer component */
 148                if (val)
 149                        return -EINVAL;
 150                ret = kxsd9_write_scale(indio_dev, val2);
 151        }
 152
 153        pm_runtime_mark_last_busy(st->dev);
 154        pm_runtime_put_autosuspend(st->dev);
 155
 156        return ret;
 157}
 158
 159static int kxsd9_read_raw(struct iio_dev *indio_dev,
 160                          struct iio_chan_spec const *chan,
 161                          int *val, int *val2, long mask)
 162{
 163        int ret = -EINVAL;
 164        struct kxsd9_state *st = iio_priv(indio_dev);
 165        unsigned int regval;
 166        __be16 raw_val;
 167        u16 nval;
 168
 169        pm_runtime_get_sync(st->dev);
 170
 171        switch (mask) {
 172        case IIO_CHAN_INFO_RAW:
 173                ret = regmap_bulk_read(st->map, chan->address, &raw_val,
 174                                       sizeof(raw_val));
 175                if (ret)
 176                        goto error_ret;
 177                nval = be16_to_cpu(raw_val);
 178                /* Only 12 bits are valid */
 179                nval >>= 4;
 180                *val = nval;
 181                ret = IIO_VAL_INT;
 182                break;
 183        case IIO_CHAN_INFO_OFFSET:
 184                /* This has a bias of -2048 */
 185                *val = KXSD9_ZERO_G_OFFSET;
 186                ret = IIO_VAL_INT;
 187                break;
 188        case IIO_CHAN_INFO_SCALE:
 189                ret = regmap_read(st->map,
 190                                  KXSD9_REG_CTRL_C,
 191                                  &regval);
 192                if (ret < 0)
 193                        goto error_ret;
 194                *val = 0;
 195                *val2 = kxsd9_micro_scales[regval & KXSD9_CTRL_C_FS_MASK];
 196                ret = IIO_VAL_INT_PLUS_MICRO;
 197                break;
 198        }
 199
 200error_ret:
 201        pm_runtime_mark_last_busy(st->dev);
 202        pm_runtime_put_autosuspend(st->dev);
 203
 204        return ret;
 205};
 206
 207static irqreturn_t kxsd9_trigger_handler(int irq, void *p)
 208{
 209        const struct iio_poll_func *pf = p;
 210        struct iio_dev *indio_dev = pf->indio_dev;
 211        struct kxsd9_state *st = iio_priv(indio_dev);
 212        /*
 213         * Ensure correct positioning and alignment of timestamp.
 214         * No need to zero initialize as all elements written.
 215         */
 216        struct {
 217                __be16 chan[4];
 218                s64 ts __aligned(8);
 219        } hw_values;
 220        int ret;
 221
 222        ret = regmap_bulk_read(st->map,
 223                               KXSD9_REG_X,
 224                               hw_values.chan,
 225                               sizeof(hw_values.chan));
 226        if (ret) {
 227                dev_err(st->dev,
 228                        "error reading data\n");
 229                return ret;
 230        }
 231
 232        iio_push_to_buffers_with_timestamp(indio_dev,
 233                                           &hw_values,
 234                                           iio_get_time_ns(indio_dev));
 235        iio_trigger_notify_done(indio_dev->trig);
 236
 237        return IRQ_HANDLED;
 238}
 239
 240static int kxsd9_buffer_preenable(struct iio_dev *indio_dev)
 241{
 242        struct kxsd9_state *st = iio_priv(indio_dev);
 243
 244        pm_runtime_get_sync(st->dev);
 245
 246        return 0;
 247}
 248
 249static int kxsd9_buffer_postdisable(struct iio_dev *indio_dev)
 250{
 251        struct kxsd9_state *st = iio_priv(indio_dev);
 252
 253        pm_runtime_mark_last_busy(st->dev);
 254        pm_runtime_put_autosuspend(st->dev);
 255
 256        return 0;
 257}
 258
 259static const struct iio_buffer_setup_ops kxsd9_buffer_setup_ops = {
 260        .preenable = kxsd9_buffer_preenable,
 261        .postdisable = kxsd9_buffer_postdisable,
 262};
 263
 264static const struct iio_mount_matrix *
 265kxsd9_get_mount_matrix(const struct iio_dev *indio_dev,
 266                       const struct iio_chan_spec *chan)
 267{
 268        struct kxsd9_state *st = iio_priv(indio_dev);
 269
 270        return &st->orientation;
 271}
 272
 273static const struct iio_chan_spec_ext_info kxsd9_ext_info[] = {
 274        IIO_MOUNT_MATRIX(IIO_SHARED_BY_TYPE, kxsd9_get_mount_matrix),
 275        { },
 276};
 277
 278#define KXSD9_ACCEL_CHAN(axis, index)                                           \
 279        {                                                               \
 280                .type = IIO_ACCEL,                                      \
 281                .modified = 1,                                          \
 282                .channel2 = IIO_MOD_##axis,                             \
 283                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
 284                .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |  \
 285                                        BIT(IIO_CHAN_INFO_OFFSET),      \
 286                .ext_info = kxsd9_ext_info,                             \
 287                .address = KXSD9_REG_##axis,                            \
 288                .scan_index = index,                                    \
 289                .scan_type = {                                          \
 290                        .sign = 'u',                                    \
 291                        .realbits = 12,                                 \
 292                        .storagebits = 16,                              \
 293                        .shift = 4,                                     \
 294                        .endianness = IIO_BE,                           \
 295                },                                                      \
 296        }
 297
 298static const struct iio_chan_spec kxsd9_channels[] = {
 299        KXSD9_ACCEL_CHAN(X, 0),
 300        KXSD9_ACCEL_CHAN(Y, 1),
 301        KXSD9_ACCEL_CHAN(Z, 2),
 302        {
 303                .type = IIO_VOLTAGE,
 304                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 305                .indexed = 1,
 306                .address = KXSD9_REG_AUX,
 307                .scan_index = 3,
 308                .scan_type = {
 309                        .sign = 'u',
 310                        .realbits = 12,
 311                        .storagebits = 16,
 312                        .shift = 4,
 313                        .endianness = IIO_BE,
 314                },
 315        },
 316        IIO_CHAN_SOFT_TIMESTAMP(4),
 317};
 318
 319static const struct attribute_group kxsd9_attribute_group = {
 320        .attrs = kxsd9_attributes,
 321};
 322
 323static int kxsd9_power_up(struct kxsd9_state *st)
 324{
 325        int ret;
 326
 327        /* Enable the regulators */
 328        ret = regulator_bulk_enable(ARRAY_SIZE(st->regs), st->regs);
 329        if (ret) {
 330                dev_err(st->dev, "Cannot enable regulators\n");
 331                return ret;
 332        }
 333
 334        /* Power up */
 335        ret = regmap_write(st->map,
 336                           KXSD9_REG_CTRL_B,
 337                           KXSD9_CTRL_B_ENABLE);
 338        if (ret)
 339                return ret;
 340
 341        /*
 342         * Set 1000Hz LPF, 2g fullscale, motion wakeup threshold 1g,
 343         * latched wakeup
 344         */
 345        ret = regmap_write(st->map,
 346                           KXSD9_REG_CTRL_C,
 347                           KXSD9_CTRL_C_LP_1000HZ |
 348                           KXSD9_CTRL_C_MOT_LEV |
 349                           KXSD9_CTRL_C_MOT_LAT |
 350                           st->scale);
 351        if (ret)
 352                return ret;
 353
 354        /*
 355         * Power-up time depends on the LPF setting, but typ 15.9 ms, let's
 356         * set 20 ms to allow for some slack.
 357         */
 358        msleep(20);
 359
 360        return 0;
 361};
 362
 363static int kxsd9_power_down(struct kxsd9_state *st)
 364{
 365        int ret;
 366
 367        /*
 368         * Set into low power mode - since there may be more users of the
 369         * regulators this is the first step of the power saving: it will
 370         * make sure we conserve power even if there are others users on the
 371         * regulators.
 372         */
 373        ret = regmap_update_bits(st->map,
 374                                 KXSD9_REG_CTRL_B,
 375                                 KXSD9_CTRL_B_ENABLE,
 376                                 0);
 377        if (ret)
 378                return ret;
 379
 380        /* Disable the regulators */
 381        ret = regulator_bulk_disable(ARRAY_SIZE(st->regs), st->regs);
 382        if (ret) {
 383                dev_err(st->dev, "Cannot disable regulators\n");
 384                return ret;
 385        }
 386
 387        return 0;
 388}
 389
 390static const struct iio_info kxsd9_info = {
 391        .read_raw = &kxsd9_read_raw,
 392        .write_raw = &kxsd9_write_raw,
 393        .attrs = &kxsd9_attribute_group,
 394};
 395
 396/* Four channels apart from timestamp, scan mask = 0x0f */
 397static const unsigned long kxsd9_scan_masks[] = { 0xf, 0 };
 398
 399int kxsd9_common_probe(struct device *dev,
 400                       struct regmap *map,
 401                       const char *name)
 402{
 403        struct iio_dev *indio_dev;
 404        struct kxsd9_state *st;
 405        int ret;
 406
 407        indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
 408        if (!indio_dev)
 409                return -ENOMEM;
 410
 411        st = iio_priv(indio_dev);
 412        st->dev = dev;
 413        st->map = map;
 414
 415        indio_dev->channels = kxsd9_channels;
 416        indio_dev->num_channels = ARRAY_SIZE(kxsd9_channels);
 417        indio_dev->name = name;
 418        indio_dev->info = &kxsd9_info;
 419        indio_dev->modes = INDIO_DIRECT_MODE;
 420        indio_dev->available_scan_masks = kxsd9_scan_masks;
 421
 422        /* Read the mounting matrix, if present */
 423        ret = iio_read_mount_matrix(dev, &st->orientation);
 424        if (ret)
 425                return ret;
 426
 427        /* Fetch and turn on regulators */
 428        st->regs[0].supply = kxsd9_reg_vdd;
 429        st->regs[1].supply = kxsd9_reg_iovdd;
 430        ret = devm_regulator_bulk_get(dev,
 431                                      ARRAY_SIZE(st->regs),
 432                                      st->regs);
 433        if (ret) {
 434                dev_err(dev, "Cannot get regulators\n");
 435                return ret;
 436        }
 437        /* Default scaling */
 438        st->scale = KXSD9_CTRL_C_FS_2G;
 439
 440        kxsd9_power_up(st);
 441
 442        ret = iio_triggered_buffer_setup(indio_dev,
 443                                         iio_pollfunc_store_time,
 444                                         kxsd9_trigger_handler,
 445                                         &kxsd9_buffer_setup_ops);
 446        if (ret) {
 447                dev_err(dev, "triggered buffer setup failed\n");
 448                goto err_power_down;
 449        }
 450
 451        ret = iio_device_register(indio_dev);
 452        if (ret)
 453                goto err_cleanup_buffer;
 454
 455        dev_set_drvdata(dev, indio_dev);
 456
 457        /* Enable runtime PM */
 458        pm_runtime_get_noresume(dev);
 459        pm_runtime_set_active(dev);
 460        pm_runtime_enable(dev);
 461        /*
 462         * Set autosuspend to two orders of magnitude larger than the
 463         * start-up time. 20ms start-up time means 2000ms autosuspend,
 464         * i.e. 2 seconds.
 465         */
 466        pm_runtime_set_autosuspend_delay(dev, 2000);
 467        pm_runtime_use_autosuspend(dev);
 468        pm_runtime_put(dev);
 469
 470        return 0;
 471
 472err_cleanup_buffer:
 473        iio_triggered_buffer_cleanup(indio_dev);
 474err_power_down:
 475        kxsd9_power_down(st);
 476
 477        return ret;
 478}
 479EXPORT_SYMBOL(kxsd9_common_probe);
 480
 481int kxsd9_common_remove(struct device *dev)
 482{
 483        struct iio_dev *indio_dev = dev_get_drvdata(dev);
 484        struct kxsd9_state *st = iio_priv(indio_dev);
 485
 486        iio_triggered_buffer_cleanup(indio_dev);
 487        iio_device_unregister(indio_dev);
 488        pm_runtime_get_sync(dev);
 489        pm_runtime_put_noidle(dev);
 490        pm_runtime_disable(dev);
 491        kxsd9_power_down(st);
 492
 493        return 0;
 494}
 495EXPORT_SYMBOL(kxsd9_common_remove);
 496
 497#ifdef CONFIG_PM
 498static int kxsd9_runtime_suspend(struct device *dev)
 499{
 500        struct iio_dev *indio_dev = dev_get_drvdata(dev);
 501        struct kxsd9_state *st = iio_priv(indio_dev);
 502
 503        return kxsd9_power_down(st);
 504}
 505
 506static int kxsd9_runtime_resume(struct device *dev)
 507{
 508        struct iio_dev *indio_dev = dev_get_drvdata(dev);
 509        struct kxsd9_state *st = iio_priv(indio_dev);
 510
 511        return kxsd9_power_up(st);
 512}
 513#endif /* CONFIG_PM */
 514
 515const struct dev_pm_ops kxsd9_dev_pm_ops = {
 516        SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
 517                                pm_runtime_force_resume)
 518        SET_RUNTIME_PM_OPS(kxsd9_runtime_suspend,
 519                           kxsd9_runtime_resume, NULL)
 520};
 521EXPORT_SYMBOL(kxsd9_dev_pm_ops);
 522
 523MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
 524MODULE_DESCRIPTION("Kionix KXSD9 driver");
 525MODULE_LICENSE("GPL v2");
 526