linux/drivers/iio/light/zopt2201.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * zopt2201.c - Support for IDT ZOPT2201 ambient light and UV B sensor
   4 *
   5 * Copyright 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net>
   6 *
   7 * Datasheet: https://www.idt.com/document/dst/zopt2201-datasheet
   8 * 7-bit I2C slave addresses 0x53 (default) or 0x52 (programmed)
   9 *
  10 * TODO: interrupt support, ALS/UVB raw mode
  11 */
  12
  13#include <linux/module.h>
  14#include <linux/i2c.h>
  15#include <linux/mutex.h>
  16#include <linux/err.h>
  17#include <linux/delay.h>
  18
  19#include <linux/iio/iio.h>
  20#include <linux/iio/sysfs.h>
  21
  22#include <asm/unaligned.h>
  23
  24#define ZOPT2201_DRV_NAME "zopt2201"
  25
  26/* Registers */
  27#define ZOPT2201_MAIN_CTRL              0x00
  28#define ZOPT2201_LS_MEAS_RATE           0x04
  29#define ZOPT2201_LS_GAIN                0x05
  30#define ZOPT2201_PART_ID                0x06
  31#define ZOPT2201_MAIN_STATUS            0x07
  32#define ZOPT2201_ALS_DATA               0x0d /* LSB first, 13 to 20 bits */
  33#define ZOPT2201_UVB_DATA               0x10 /* LSB first, 13 to 20 bits */
  34#define ZOPT2201_UV_COMP_DATA           0x13 /* LSB first, 13 to 20 bits */
  35#define ZOPT2201_COMP_DATA              0x16 /* LSB first, 13 to 20 bits */
  36#define ZOPT2201_INT_CFG                0x19
  37#define ZOPT2201_INT_PST                0x1a
  38
  39#define ZOPT2201_MAIN_CTRL_LS_MODE      BIT(3) /* 0 .. ALS, 1 .. UV B */
  40#define ZOPT2201_MAIN_CTRL_LS_EN        BIT(1)
  41
  42/* Values for ZOPT2201_LS_MEAS_RATE resolution / bit width */
  43#define ZOPT2201_MEAS_RES_20BIT         0 /* takes 400 ms */
  44#define ZOPT2201_MEAS_RES_19BIT         1 /* takes 200 ms */
  45#define ZOPT2201_MEAS_RES_18BIT         2 /* takes 100 ms, default */
  46#define ZOPT2201_MEAS_RES_17BIT         3 /* takes 50 ms */
  47#define ZOPT2201_MEAS_RES_16BIT         4 /* takes 25 ms */
  48#define ZOPT2201_MEAS_RES_13BIT         5 /* takes 3.125 ms */
  49#define ZOPT2201_MEAS_RES_SHIFT         4
  50
  51/* Values for ZOPT2201_LS_MEAS_RATE measurement rate */
  52#define ZOPT2201_MEAS_FREQ_25MS         0
  53#define ZOPT2201_MEAS_FREQ_50MS         1
  54#define ZOPT2201_MEAS_FREQ_100MS        2 /* default */
  55#define ZOPT2201_MEAS_FREQ_200MS        3
  56#define ZOPT2201_MEAS_FREQ_500MS        4
  57#define ZOPT2201_MEAS_FREQ_1000MS       5
  58#define ZOPT2201_MEAS_FREQ_2000MS       6
  59
  60/* Values for ZOPT2201_LS_GAIN */
  61#define ZOPT2201_LS_GAIN_1              0
  62#define ZOPT2201_LS_GAIN_3              1
  63#define ZOPT2201_LS_GAIN_6              2
  64#define ZOPT2201_LS_GAIN_9              3
  65#define ZOPT2201_LS_GAIN_18             4
  66
  67/* Values for ZOPT2201_MAIN_STATUS */
  68#define ZOPT2201_MAIN_STATUS_POWERON    BIT(5)
  69#define ZOPT2201_MAIN_STATUS_INT        BIT(4)
  70#define ZOPT2201_MAIN_STATUS_DRDY       BIT(3)
  71
  72#define ZOPT2201_PART_NUMBER            0xb2
  73
  74struct zopt2201_data {
  75        struct i2c_client *client;
  76        struct mutex lock;
  77        u8 gain;
  78        u8 res;
  79        u8 rate;
  80};
  81
  82static const struct {
  83        unsigned int gain; /* gain factor */
  84        unsigned int scale; /* micro lux per count */
  85} zopt2201_gain_als[] = {
  86        {  1, 19200000 },
  87        {  3,  6400000 },
  88        {  6,  3200000 },
  89        {  9,  2133333 },
  90        { 18,  1066666 },
  91};
  92
  93static const struct {
  94        unsigned int gain; /* gain factor */
  95        unsigned int scale; /* micro W/m2 per count */
  96} zopt2201_gain_uvb[] = {
  97        {  1, 460800 },
  98        {  3, 153600 },
  99        {  6,  76800 },
 100        {  9,  51200 },
 101        { 18,  25600 },
 102};
 103
 104static const struct {
 105        unsigned int bits; /* sensor resolution in bits */
 106        unsigned long us; /* measurement time in micro seconds */
 107} zopt2201_resolution[] = {
 108        { 20, 400000 },
 109        { 19, 200000 },
 110        { 18, 100000 },
 111        { 17,  50000 },
 112        { 16,  25000 },
 113        { 13,   3125 },
 114};
 115
 116static const struct {
 117        unsigned int scale, uscale; /* scale factor as integer + micro */
 118        u8 gain; /* gain register value */
 119        u8 res; /* resolution register value */
 120} zopt2201_scale_als[] = {
 121        { 19, 200000, 0, 5 },
 122        {  6, 400000, 1, 5 },
 123        {  3, 200000, 2, 5 },
 124        {  2, 400000, 0, 4 },
 125        {  2, 133333, 3, 5 },
 126        {  1, 200000, 0, 3 },
 127        {  1,  66666, 4, 5 },
 128        {  0, 800000, 1, 4 },
 129        {  0, 600000, 0, 2 },
 130        {  0, 400000, 2, 4 },
 131        {  0, 300000, 0, 1 },
 132        {  0, 266666, 3, 4 },
 133        {  0, 200000, 2, 3 },
 134        {  0, 150000, 0, 0 },
 135        {  0, 133333, 4, 4 },
 136        {  0, 100000, 2, 2 },
 137        {  0,  66666, 4, 3 },
 138        {  0,  50000, 2, 1 },
 139        {  0,  33333, 4, 2 },
 140        {  0,  25000, 2, 0 },
 141        {  0,  16666, 4, 1 },
 142        {  0,   8333, 4, 0 },
 143};
 144
 145static const struct {
 146        unsigned int scale, uscale; /* scale factor as integer + micro */
 147        u8 gain; /* gain register value */
 148        u8 res; /* resolution register value */
 149} zopt2201_scale_uvb[] = {
 150        { 0, 460800, 0, 5 },
 151        { 0, 153600, 1, 5 },
 152        { 0,  76800, 2, 5 },
 153        { 0,  57600, 0, 4 },
 154        { 0,  51200, 3, 5 },
 155        { 0,  28800, 0, 3 },
 156        { 0,  25600, 4, 5 },
 157        { 0,  19200, 1, 4 },
 158        { 0,  14400, 0, 2 },
 159        { 0,   9600, 2, 4 },
 160        { 0,   7200, 0, 1 },
 161        { 0,   6400, 3, 4 },
 162        { 0,   4800, 2, 3 },
 163        { 0,   3600, 0, 0 },
 164        { 0,   3200, 4, 4 },
 165        { 0,   2400, 2, 2 },
 166        { 0,   1600, 4, 3 },
 167        { 0,   1200, 2, 1 },
 168        { 0,    800, 4, 2 },
 169        { 0,    600, 2, 0 },
 170        { 0,    400, 4, 1 },
 171        { 0,    200, 4, 0 },
 172};
 173
 174static int zopt2201_enable_mode(struct zopt2201_data *data, bool uvb_mode)
 175{
 176        u8 out = ZOPT2201_MAIN_CTRL_LS_EN;
 177
 178        if (uvb_mode)
 179                out |= ZOPT2201_MAIN_CTRL_LS_MODE;
 180
 181        return i2c_smbus_write_byte_data(data->client, ZOPT2201_MAIN_CTRL, out);
 182}
 183
 184static int zopt2201_read(struct zopt2201_data *data, u8 reg)
 185{
 186        struct i2c_client *client = data->client;
 187        int tries = 10;
 188        u8 buf[3];
 189        int ret;
 190
 191        mutex_lock(&data->lock);
 192        ret = zopt2201_enable_mode(data, reg == ZOPT2201_UVB_DATA);
 193        if (ret < 0)
 194                goto fail;
 195
 196        while (tries--) {
 197                unsigned long t = zopt2201_resolution[data->res].us;
 198
 199                if (t <= 20000)
 200                        usleep_range(t, t + 1000);
 201                else
 202                        msleep(t / 1000);
 203                ret = i2c_smbus_read_byte_data(client, ZOPT2201_MAIN_STATUS);
 204                if (ret < 0)
 205                        goto fail;
 206                if (ret & ZOPT2201_MAIN_STATUS_DRDY)
 207                        break;
 208        }
 209
 210        if (tries < 0) {
 211                ret = -ETIMEDOUT;
 212                goto fail;
 213        }
 214
 215        ret = i2c_smbus_read_i2c_block_data(client, reg, sizeof(buf), buf);
 216        if (ret < 0)
 217                goto fail;
 218
 219        ret = i2c_smbus_write_byte_data(client, ZOPT2201_MAIN_CTRL, 0x00);
 220        if (ret < 0)
 221                goto fail;
 222        mutex_unlock(&data->lock);
 223
 224        return get_unaligned_le24(&buf[0]);
 225
 226fail:
 227        mutex_unlock(&data->lock);
 228        return ret;
 229}
 230
 231static const struct iio_chan_spec zopt2201_channels[] = {
 232        {
 233                .type = IIO_LIGHT,
 234                .address = ZOPT2201_ALS_DATA,
 235                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 236                                      BIT(IIO_CHAN_INFO_SCALE),
 237                .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
 238        },
 239        {
 240                .type = IIO_INTENSITY,
 241                .modified = 1,
 242                .channel2 = IIO_MOD_LIGHT_UV,
 243                .address = ZOPT2201_UVB_DATA,
 244                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 245                                      BIT(IIO_CHAN_INFO_SCALE),
 246                .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
 247        },
 248        {
 249                .type = IIO_UVINDEX,
 250                .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
 251        },
 252};
 253
 254static int zopt2201_read_raw(struct iio_dev *indio_dev,
 255                                struct iio_chan_spec const *chan,
 256                                int *val, int *val2, long mask)
 257{
 258        struct zopt2201_data *data = iio_priv(indio_dev);
 259        u64 tmp;
 260        int ret;
 261
 262        switch (mask) {
 263        case IIO_CHAN_INFO_RAW:
 264                ret = zopt2201_read(data, chan->address);
 265                if (ret < 0)
 266                        return ret;
 267                *val = ret;
 268                return IIO_VAL_INT;
 269        case IIO_CHAN_INFO_PROCESSED:
 270                ret = zopt2201_read(data, ZOPT2201_UVB_DATA);
 271                if (ret < 0)
 272                        return ret;
 273                *val = ret * 18 *
 274                        (1 << (20 - zopt2201_resolution[data->res].bits)) /
 275                        zopt2201_gain_uvb[data->gain].gain;
 276                return IIO_VAL_INT;
 277        case IIO_CHAN_INFO_SCALE:
 278                switch (chan->address) {
 279                case ZOPT2201_ALS_DATA:
 280                        *val = zopt2201_gain_als[data->gain].scale;
 281                        break;
 282                case ZOPT2201_UVB_DATA:
 283                        *val = zopt2201_gain_uvb[data->gain].scale;
 284                        break;
 285                default:
 286                        return -EINVAL;
 287                }
 288
 289                *val2 = 1000000;
 290                *val2 *= (1 << (zopt2201_resolution[data->res].bits - 13));
 291                tmp = div_s64(*val * 1000000ULL, *val2);
 292                *val = div_s64_rem(tmp, 1000000, val2);
 293
 294                return IIO_VAL_INT_PLUS_MICRO;
 295        case IIO_CHAN_INFO_INT_TIME:
 296                *val = 0;
 297                *val2 = zopt2201_resolution[data->res].us;
 298                return IIO_VAL_INT_PLUS_MICRO;
 299        default:
 300                return -EINVAL;
 301        }
 302}
 303
 304static int zopt2201_set_resolution(struct zopt2201_data *data, u8 res)
 305{
 306        int ret;
 307
 308        ret = i2c_smbus_write_byte_data(data->client, ZOPT2201_LS_MEAS_RATE,
 309                                        (res << ZOPT2201_MEAS_RES_SHIFT) |
 310                                        data->rate);
 311        if (ret < 0)
 312                return ret;
 313
 314        data->res = res;
 315
 316        return 0;
 317}
 318
 319static int zopt2201_write_resolution(struct zopt2201_data *data,
 320                                     int val, int val2)
 321{
 322        int i, ret;
 323
 324        if (val != 0)
 325                return -EINVAL;
 326
 327        for (i = 0; i < ARRAY_SIZE(zopt2201_resolution); i++)
 328                if (val2 == zopt2201_resolution[i].us) {
 329                        mutex_lock(&data->lock);
 330                        ret = zopt2201_set_resolution(data, i);
 331                        mutex_unlock(&data->lock);
 332                        return ret;
 333                }
 334
 335        return -EINVAL;
 336}
 337
 338static int zopt2201_set_gain(struct zopt2201_data *data, u8 gain)
 339{
 340        int ret;
 341
 342        ret = i2c_smbus_write_byte_data(data->client, ZOPT2201_LS_GAIN, gain);
 343        if (ret < 0)
 344                return ret;
 345
 346        data->gain = gain;
 347
 348        return 0;
 349}
 350
 351static int zopt2201_write_scale_als_by_idx(struct zopt2201_data *data, int idx)
 352{
 353        int ret;
 354
 355        mutex_lock(&data->lock);
 356        ret = zopt2201_set_resolution(data, zopt2201_scale_als[idx].res);
 357        if (ret < 0)
 358                goto unlock;
 359
 360        ret = zopt2201_set_gain(data, zopt2201_scale_als[idx].gain);
 361
 362unlock:
 363        mutex_unlock(&data->lock);
 364        return ret;
 365}
 366
 367static int zopt2201_write_scale_als(struct zopt2201_data *data,
 368                                     int val, int val2)
 369{
 370        int i;
 371
 372        for (i = 0; i < ARRAY_SIZE(zopt2201_scale_als); i++)
 373                if (val == zopt2201_scale_als[i].scale &&
 374                    val2 == zopt2201_scale_als[i].uscale) {
 375                        return zopt2201_write_scale_als_by_idx(data, i);
 376                }
 377
 378        return -EINVAL;
 379}
 380
 381static int zopt2201_write_scale_uvb_by_idx(struct zopt2201_data *data, int idx)
 382{
 383        int ret;
 384
 385        mutex_lock(&data->lock);
 386        ret = zopt2201_set_resolution(data, zopt2201_scale_als[idx].res);
 387        if (ret < 0)
 388                goto unlock;
 389
 390        ret = zopt2201_set_gain(data, zopt2201_scale_als[idx].gain);
 391
 392unlock:
 393        mutex_unlock(&data->lock);
 394        return ret;
 395}
 396
 397static int zopt2201_write_scale_uvb(struct zopt2201_data *data,
 398                                     int val, int val2)
 399{
 400        int i;
 401
 402        for (i = 0; i < ARRAY_SIZE(zopt2201_scale_uvb); i++)
 403                if (val == zopt2201_scale_uvb[i].scale &&
 404                    val2 == zopt2201_scale_uvb[i].uscale)
 405                        return zopt2201_write_scale_uvb_by_idx(data, i);
 406
 407        return -EINVAL;
 408}
 409
 410static int zopt2201_write_raw(struct iio_dev *indio_dev,
 411                              struct iio_chan_spec const *chan,
 412                              int val, int val2, long mask)
 413{
 414        struct zopt2201_data *data = iio_priv(indio_dev);
 415
 416        switch (mask) {
 417        case IIO_CHAN_INFO_INT_TIME:
 418                return zopt2201_write_resolution(data, val, val2);
 419        case IIO_CHAN_INFO_SCALE:
 420                switch (chan->address) {
 421                case ZOPT2201_ALS_DATA:
 422                        return zopt2201_write_scale_als(data, val, val2);
 423                case ZOPT2201_UVB_DATA:
 424                        return zopt2201_write_scale_uvb(data, val, val2);
 425                default:
 426                        return -EINVAL;
 427                }
 428        }
 429
 430        return -EINVAL;
 431}
 432
 433static ssize_t zopt2201_show_int_time_available(struct device *dev,
 434                                                struct device_attribute *attr,
 435                                                char *buf)
 436{
 437        size_t len = 0;
 438        int i;
 439
 440        for (i = 0; i < ARRAY_SIZE(zopt2201_resolution); i++)
 441                len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06lu ",
 442                                 zopt2201_resolution[i].us);
 443        buf[len - 1] = '\n';
 444
 445        return len;
 446}
 447
 448static IIO_DEV_ATTR_INT_TIME_AVAIL(zopt2201_show_int_time_available);
 449
 450static ssize_t zopt2201_show_als_scale_avail(struct device *dev,
 451                                             struct device_attribute *attr,
 452                                             char *buf)
 453{
 454        ssize_t len = 0;
 455        int i;
 456
 457        for (i = 0; i < ARRAY_SIZE(zopt2201_scale_als); i++)
 458                len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06u ",
 459                                 zopt2201_scale_als[i].scale,
 460                                 zopt2201_scale_als[i].uscale);
 461        buf[len - 1] = '\n';
 462
 463        return len;
 464}
 465
 466static ssize_t zopt2201_show_uvb_scale_avail(struct device *dev,
 467                                             struct device_attribute *attr,
 468                                             char *buf)
 469{
 470        ssize_t len = 0;
 471        int i;
 472
 473        for (i = 0; i < ARRAY_SIZE(zopt2201_scale_uvb); i++)
 474                len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06u ",
 475                                 zopt2201_scale_uvb[i].scale,
 476                                 zopt2201_scale_uvb[i].uscale);
 477        buf[len - 1] = '\n';
 478
 479        return len;
 480}
 481
 482static IIO_DEVICE_ATTR(in_illuminance_scale_available, 0444,
 483                       zopt2201_show_als_scale_avail, NULL, 0);
 484static IIO_DEVICE_ATTR(in_intensity_uv_scale_available, 0444,
 485                       zopt2201_show_uvb_scale_avail, NULL, 0);
 486
 487static struct attribute *zopt2201_attributes[] = {
 488        &iio_dev_attr_integration_time_available.dev_attr.attr,
 489        &iio_dev_attr_in_illuminance_scale_available.dev_attr.attr,
 490        &iio_dev_attr_in_intensity_uv_scale_available.dev_attr.attr,
 491        NULL
 492};
 493
 494static const struct attribute_group zopt2201_attribute_group = {
 495        .attrs = zopt2201_attributes,
 496};
 497
 498static const struct iio_info zopt2201_info = {
 499        .read_raw = zopt2201_read_raw,
 500        .write_raw = zopt2201_write_raw,
 501        .attrs = &zopt2201_attribute_group,
 502};
 503
 504static int zopt2201_probe(struct i2c_client *client,
 505                          const struct i2c_device_id *id)
 506{
 507        struct zopt2201_data *data;
 508        struct iio_dev *indio_dev;
 509        int ret;
 510
 511        if (!i2c_check_functionality(client->adapter,
 512                                     I2C_FUNC_SMBUS_READ_I2C_BLOCK))
 513                return -EOPNOTSUPP;
 514
 515        ret = i2c_smbus_read_byte_data(client, ZOPT2201_PART_ID);
 516        if (ret < 0)
 517                return ret;
 518        if (ret != ZOPT2201_PART_NUMBER)
 519                return -ENODEV;
 520
 521        indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 522        if (!indio_dev)
 523                return -ENOMEM;
 524
 525        data = iio_priv(indio_dev);
 526        i2c_set_clientdata(client, indio_dev);
 527        data->client = client;
 528        mutex_init(&data->lock);
 529
 530        indio_dev->info = &zopt2201_info;
 531        indio_dev->channels = zopt2201_channels;
 532        indio_dev->num_channels = ARRAY_SIZE(zopt2201_channels);
 533        indio_dev->name = ZOPT2201_DRV_NAME;
 534        indio_dev->modes = INDIO_DIRECT_MODE;
 535
 536        data->rate = ZOPT2201_MEAS_FREQ_100MS;
 537        ret = zopt2201_set_resolution(data, ZOPT2201_MEAS_RES_18BIT);
 538        if (ret < 0)
 539                return ret;
 540
 541        ret = zopt2201_set_gain(data, ZOPT2201_LS_GAIN_3);
 542        if (ret < 0)
 543                return ret;
 544
 545        return devm_iio_device_register(&client->dev, indio_dev);
 546}
 547
 548static const struct i2c_device_id zopt2201_id[] = {
 549        { "zopt2201", 0 },
 550        { }
 551};
 552MODULE_DEVICE_TABLE(i2c, zopt2201_id);
 553
 554static struct i2c_driver zopt2201_driver = {
 555        .driver = {
 556                .name   = ZOPT2201_DRV_NAME,
 557        },
 558        .probe  = zopt2201_probe,
 559        .id_table = zopt2201_id,
 560};
 561
 562module_i2c_driver(zopt2201_driver);
 563
 564MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>");
 565MODULE_DESCRIPTION("IDT ZOPT2201 ambient light and UV B sensor driver");
 566MODULE_LICENSE("GPL");
 567