drivers/iio/light/us5182d.c

   1 /*
   2  * Copyright (c) 2015 Intel Corporation
   3  *
   4  * Driver for UPISEMI us5182d Proximity and Ambient Light Sensor.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published by
   8  * 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  * To do: Interrupt support.
  16  */
  17
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/acpi.h>
  21 #include <linux/delay.h>
  22 #include <linux/i2c.h>
  23 #include <linux/iio/iio.h>
  24 #include <linux/iio/sysfs.h>
  25 #include <linux/mutex.h>
  26
  27 #define US5182D_REG_CFG0                                0x00
  28 #define US5182D_CFG0_ONESHOT_EN                         BIT(6)
  29 #define US5182D_CFG0_SHUTDOWN_EN                        BIT(7)
  30 #define US5182D_CFG0_WORD_ENABLE                        BIT(0)
  31
  32 #define US5182D_REG_CFG1                                0x01
  33 #define US5182D_CFG1_ALS_RES16                          BIT(4)
  34 #define US5182D_CFG1_AGAIN_DEFAULT                      0x00
  35
  36 #define US5182D_REG_CFG2                                0x02
  37 #define US5182D_CFG2_PX_RES16                           BIT(4)
  38 #define US5182D_CFG2_PXGAIN_DEFAULT                     BIT(2)
  39
  40 #define US5182D_REG_CFG3                                0x03
  41 #define US5182D_CFG3_LED_CURRENT100                     (BIT(4) | BIT(5))
  42
  43 #define US5182D_REG_CFG4                                0x10
  44
  45 /*
  46  * Registers for tuning the auto dark current cancelling feature.
  47  * DARK_TH(reg 0x27,0x28) - threshold (counts) for auto dark cancelling.
  48  * when ALS  > DARK_TH --> ALS_Code = ALS - Upper(0x2A) * Dark
  49  * when ALS < DARK_TH --> ALS_Code = ALS - Lower(0x29) * Dark
  50  */
  51 #define US5182D_REG_UDARK_TH                    0x27
  52 #define US5182D_REG_DARK_AUTO_EN                0x2b
  53 #define US5182D_REG_AUTO_LDARK_GAIN             0x29
  54 #define US5182D_REG_AUTO_HDARK_GAIN             0x2a
  55
  56 #define US5182D_OPMODE_ALS                      0x01
  57 #define US5182D_OPMODE_PX                       0x02
  58 #define US5182D_OPMODE_SHIFT                    4
  59
  60 #define US5182D_REG_DARK_AUTO_EN_DEFAULT        0x80
  61 #define US5182D_REG_AUTO_LDARK_GAIN_DEFAULT     0x16
  62 #define US5182D_REG_AUTO_HDARK_GAIN_DEFAULT     0x00
  63
  64 #define US5182D_REG_ADL                         0x0c
  65 #define US5182D_REG_PDL                         0x0e
  66
  67 #define US5182D_REG_MODE_STORE                  0x21
  68 #define US5182D_STORE_MODE                      0x01
  69
  70 #define US5182D_REG_CHIPID                      0xb2
  71
  72 #define US5182D_OPMODE_MASK                     GENMASK(5, 4)
  73 #define US5182D_AGAIN_MASK                      0x07
  74 #define US5182D_RESET_CHIP                      0x01
  75
  76 #define US5182D_CHIPID                          0x26
  77 #define US5182D_DRV_NAME                        "us5182d"
  78
  79 #define US5182D_GA_RESOLUTION                   1000
  80
  81 #define US5182D_READ_BYTE                       1
  82 #define US5182D_READ_WORD                       2
  83 #define US5182D_OPSTORE_SLEEP_TIME              20 /* ms */
  84
  85 /* Available ranges: [12354, 7065, 3998, 2202, 1285, 498, 256, 138] lux */
  86 static const int us5182d_scales[] = {188500, 107800, 61000, 33600, 19600, 7600,
  87                                      3900, 2100};
  88
  89 /*
  90  * Experimental thresholds that work with US5182D sensor on evaluation board
  91  * roughly between 12-32 lux
  92  */
  93 static u16 us5182d_dark_ths_vals[] = {170, 200, 512, 512, 800, 2000, 4000,
  94                                       8000};
  95
  96 enum mode {
  97         US5182D_ALS_PX,
  98         US5182D_ALS_ONLY,
  99         US5182D_PX_ONLY
 100 };
 101
 102 struct us5182d_data {
 103         struct i2c_client *client;
 104         struct mutex lock;
 105
 106         /* Glass attenuation factor */
 107         u32 ga;
 108
 109         /* Dark gain tuning */
 110         u8 lower_dark_gain;
 111         u8 upper_dark_gain;
 112         u16 *us5182d_dark_ths;
 113
 114         u8 opmode;
 115 };
 116
 117 static IIO_CONST_ATTR(in_illuminance_scale_available,
 118                       "0.0021 0.0039 0.0076 0.0196 0.0336 0.061 0.1078 0.1885");
 119
 120 static struct attribute *us5182d_attrs[] = {
 121         &iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
 122         NULL
 123 };
 124
 125 static const struct attribute_group us5182d_attr_group = {
 126         .attrs = us5182d_attrs,
 127 };
 128
 129 static const struct {
 130         u8 reg;
 131         u8 val;
 132 } us5182d_regvals[] = {
 133         {US5182D_REG_CFG0, (US5182D_CFG0_SHUTDOWN_EN |
 134                             US5182D_CFG0_WORD_ENABLE)},
 135         {US5182D_REG_CFG1, US5182D_CFG1_ALS_RES16},
 136         {US5182D_REG_CFG2, (US5182D_CFG2_PX_RES16 |
 137                             US5182D_CFG2_PXGAIN_DEFAULT)},
 138         {US5182D_REG_CFG3, US5182D_CFG3_LED_CURRENT100},
 139         {US5182D_REG_MODE_STORE, US5182D_STORE_MODE},
 140         {US5182D_REG_CFG4, 0x00},
 141 };
 142
 143 static const struct iio_chan_spec us5182d_channels[] = {
 144         {
 145                 .type = IIO_LIGHT,
 146                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 147                                       BIT(IIO_CHAN_INFO_SCALE),
 148         },
 149         {
 150                 .type = IIO_PROXIMITY,
 151                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 152         }
 153 };
 154
 155 static int us5182d_get_als(struct us5182d_data *data)
 156 {
 157         int ret;
 158         unsigned long result;
 159
 160         ret = i2c_smbus_read_word_data(data->client,
 161                                        US5182D_REG_ADL);
 162         if (ret < 0)
 163                 return ret;
 164
 165         result = ret * data->ga / US5182D_GA_RESOLUTION;
 166         if (result > 0xffff)
 167                 result = 0xffff;
 168
 169         return result;
 170 }
 171
 172 static int us5182d_set_opmode(struct us5182d_data *data, u8 mode)
 173 {
 174         int ret;
 175
 176         ret = i2c_smbus_read_byte_data(data->client, US5182D_REG_CFG0);
 177         if (ret < 0)
 178                 return ret;
 179
 180         /*
 181          * In oneshot mode the chip will power itself down after taking the
 182          * required measurement.
 183          */
 184         ret = ret | US5182D_CFG0_ONESHOT_EN;
 185
 186         /* update mode */
 187         ret = ret & ~US5182D_OPMODE_MASK;
 188         ret = ret | (mode << US5182D_OPMODE_SHIFT);
 189
 190         /*
 191          * After updating the operating mode, the chip requires that
 192          * the operation is stored, by writing 1 in the STORE_MODE
 193          * register (auto-clearing).
 194          */
 195         ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_CFG0, ret);
 196         if (ret < 0)
 197                 return ret;
 198
 199         if (mode == data->opmode)
 200                 return 0;
 201
 202         ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_MODE_STORE,
 203                                         US5182D_STORE_MODE);
 204         if (ret < 0)
 205                 return ret;
 206
 207         data->opmode = mode;
 208         msleep(US5182D_OPSTORE_SLEEP_TIME);
 209
 210         return 0;
 211 }
 212
 213 static int us5182d_read_raw(struct iio_dev *indio_dev,
 214                             struct iio_chan_spec const *chan, int *val,
 215                             int *val2, long mask)
 216 {
 217         struct us5182d_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_LIGHT:
 224                         mutex_lock(&data->lock);
 225                         ret = us5182d_set_opmode(data, US5182D_OPMODE_ALS);
 226                         if (ret < 0)
 227                                 goto out_err;
 228
 229                         ret = us5182d_get_als(data);
 230                         if (ret < 0)
 231                                 goto out_err;
 232                         mutex_unlock(&data->lock);
 233                         *val = ret;
 234                         return IIO_VAL_INT;
 235                 case IIO_PROXIMITY:
 236                         mutex_lock(&data->lock);
 237                         ret = us5182d_set_opmode(data, US5182D_OPMODE_PX);
 238                         if (ret < 0)
 239                                 goto out_err;
 240
 241                         ret = i2c_smbus_read_word_data(data->client,
 242                                                        US5182D_REG_PDL);
 243                         if (ret < 0)
 244                                 goto out_err;
 245                         mutex_unlock(&data->lock);
 246                         *val = ret;
 247                         return  IIO_VAL_INT;
 248                 default:
 249                         return -EINVAL;
 250                 }
 251
 252         case IIO_CHAN_INFO_SCALE:
 253                 ret = i2c_smbus_read_byte_data(data->client, US5182D_REG_CFG1);
 254                 if (ret < 0)
 255                         return ret;
 256
 257                 *val = 0;
 258                 *val2 = us5182d_scales[ret & US5182D_AGAIN_MASK];
 259
 260                 return IIO_VAL_INT_PLUS_MICRO;
 261         default:
 262                 return -EINVAL;
 263         }
 264
 265         return -EINVAL;
 266 out_err:
 267         mutex_unlock(&data->lock);
 268         return ret;
 269 }
 270
 271 /**
 272  * us5182d_update_dark_th - update Darh_Th registers
 273  * @data        us5182d_data structure
 274  * @index       index in us5182d_dark_ths array to use for the updated value
 275  *
 276  * Function needs to be called with a lock held because it needs two i2c write
 277  * byte operations as these registers (0x27 0x28) don't work in word mode
 278  * accessing.
 279  */
 280 static int us5182d_update_dark_th(struct us5182d_data *data, int index)
 281 {
 282         __be16 dark_th = cpu_to_be16(data->us5182d_dark_ths[index]);
 283         int ret;
 284
 285         ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_UDARK_TH,
 286                                         ((u8 *)&dark_th)[0]);
 287         if (ret < 0)
 288                 return ret;
 289
 290         return i2c_smbus_write_byte_data(data->client, US5182D_REG_UDARK_TH + 1,
 291                                         ((u8 *)&dark_th)[1]);
 292 }
 293
 294 /**
 295  * us5182d_apply_scale - update the ALS scale
 296  * @data        us5182d_data structure
 297  * @index       index in us5182d_scales array to use for the updated value
 298  *
 299  * Function needs to be called with a lock held as we're having more than one
 300  * i2c operation.
 301  */
 302 static int us5182d_apply_scale(struct us5182d_data *data, int index)
 303 {
 304         int ret;
 305
 306         ret = i2c_smbus_read_byte_data(data->client, US5182D_REG_CFG1);
 307         if (ret < 0)
 308                 return ret;
 309
 310         ret = ret & (~US5182D_AGAIN_MASK);
 311         ret |= index;
 312
 313         ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_CFG1, ret);
 314         if (ret < 0)
 315                 return ret;
 316
 317         return us5182d_update_dark_th(data, index);
 318 }
 319
 320 static int us5182d_write_raw(struct iio_dev *indio_dev,
 321                              struct iio_chan_spec const *chan, int val,
 322                              int val2, long mask)
 323 {
 324         struct us5182d_data *data = iio_priv(indio_dev);
 325         int ret, i;
 326
 327         switch (mask) {
 328         case IIO_CHAN_INFO_SCALE:
 329                 if (val != 0)
 330                         return -EINVAL;
 331                 for (i = 0; i < ARRAY_SIZE(us5182d_scales); i++)
 332                         if (val2 == us5182d_scales[i]) {
 333                                 mutex_lock(&data->lock);
 334                                 ret = us5182d_apply_scale(data, i);
 335                                 mutex_unlock(&data->lock);
 336                                 return ret;
 337                         }
 338                 break;
 339         default:
 340                 return -EINVAL;
 341         }
 342
 343         return -EINVAL;
 344 }
 345
 346 static const struct iio_info us5182d_info = {
 347         .driver_module  = THIS_MODULE,
 348         .read_raw = us5182d_read_raw,
 349         .write_raw = us5182d_write_raw,
 350         .attrs = &us5182d_attr_group,
 351 };
 352
 353 static int us5182d_reset(struct iio_dev *indio_dev)
 354 {
 355         struct us5182d_data *data = iio_priv(indio_dev);
 356
 357         return i2c_smbus_write_byte_data(data->client, US5182D_REG_CFG3,
 358                                          US5182D_RESET_CHIP);
 359 }
 360
 361 static int us5182d_init(struct iio_dev *indio_dev)
 362 {
 363         struct us5182d_data *data = iio_priv(indio_dev);
 364         int i, ret;
 365
 366         ret = us5182d_reset(indio_dev);
 367         if (ret < 0)
 368                 return ret;
 369
 370         data->opmode = 0;
 371         for (i = 0; i < ARRAY_SIZE(us5182d_regvals); i++) {
 372                 ret = i2c_smbus_write_byte_data(data->client,
 373                                                 us5182d_regvals[i].reg,
 374                                                 us5182d_regvals[i].val);
 375                 if (ret < 0)
 376                         return ret;
 377         }
 378
 379         return 0;
 380 }
 381
 382 static void us5182d_get_platform_data(struct iio_dev *indio_dev)
 383 {
 384         struct us5182d_data *data = iio_priv(indio_dev);
 385
 386         if (device_property_read_u32(&data->client->dev, "upisemi,glass-coef",
 387                                      &data->ga))
 388                 data->ga = US5182D_GA_RESOLUTION;
 389         if (device_property_read_u16_array(&data->client->dev,
 390                                            "upisemi,dark-ths",
 391                                            data->us5182d_dark_ths,
 392                                            ARRAY_SIZE(us5182d_dark_ths_vals)))
 393                 data->us5182d_dark_ths = us5182d_dark_ths_vals;
 394         if (device_property_read_u8(&data->client->dev,
 395                                     "upisemi,upper-dark-gain",
 396                                     &data->upper_dark_gain))
 397                 data->upper_dark_gain = US5182D_REG_AUTO_HDARK_GAIN_DEFAULT;
 398         if (device_property_read_u8(&data->client->dev,
 399                                     "upisemi,lower-dark-gain",
 400                                     &data->lower_dark_gain))
 401                 data->lower_dark_gain = US5182D_REG_AUTO_LDARK_GAIN_DEFAULT;
 402 }
 403
 404 static int  us5182d_dark_gain_config(struct iio_dev *indio_dev)
 405 {
 406         struct us5182d_data *data = iio_priv(indio_dev);
 407         int ret;
 408
 409         ret = us5182d_update_dark_th(data, US5182D_CFG1_AGAIN_DEFAULT);
 410         if (ret < 0)
 411                 return ret;
 412
 413         ret = i2c_smbus_write_byte_data(data->client,
 414                                         US5182D_REG_AUTO_LDARK_GAIN,
 415                                         data->lower_dark_gain);
 416         if (ret < 0)
 417                 return ret;
 418
 419         ret = i2c_smbus_write_byte_data(data->client,
 420                                         US5182D_REG_AUTO_HDARK_GAIN,
 421                                         data->upper_dark_gain);
 422         if (ret < 0)
 423                 return ret;
 424
 425         return i2c_smbus_write_byte_data(data->client, US5182D_REG_DARK_AUTO_EN,
 426                                          US5182D_REG_DARK_AUTO_EN_DEFAULT);
 427 }
 428
 429 static int us5182d_probe(struct i2c_client *client,
 430                          const struct i2c_device_id *id)
 431 {
 432         struct us5182d_data *data;
 433         struct iio_dev *indio_dev;
 434         int ret;
 435
 436         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 437         if (!indio_dev)
 438                 return -ENOMEM;
 439
 440         data = iio_priv(indio_dev);
 441         i2c_set_clientdata(client, indio_dev);
 442         data->client = client;
 443
 444         mutex_init(&data->lock);
 445
 446         indio_dev->dev.parent = &client->dev;
 447         indio_dev->info = &us5182d_info;
 448         indio_dev->name = US5182D_DRV_NAME;
 449         indio_dev->channels = us5182d_channels;
 450         indio_dev->num_channels = ARRAY_SIZE(us5182d_channels);
 451         indio_dev->modes = INDIO_DIRECT_MODE;
 452
 453         ret = i2c_smbus_read_byte_data(data->client, US5182D_REG_CHIPID);
 454         if (ret != US5182D_CHIPID) {
 455                 dev_err(&data->client->dev,
 456                         "Failed to detect US5182 light chip\n");
 457                 return (ret < 0) ? ret : -ENODEV;
 458         }
 459
 460         us5182d_get_platform_data(indio_dev);
 461         ret = us5182d_init(indio_dev);
 462         if (ret < 0)
 463                 return ret;
 464
 465         ret = us5182d_dark_gain_config(indio_dev);
 466         if (ret < 0)
 467                 return ret;
 468
 469         return iio_device_register(indio_dev);
 470 }
 471
 472 static int us5182d_remove(struct i2c_client *client)
 473 {
 474         iio_device_unregister(i2c_get_clientdata(client));
 475         return i2c_smbus_write_byte_data(client, US5182D_REG_CFG0,
 476                                          US5182D_CFG0_SHUTDOWN_EN);
 477 }
 478
 479 static const struct acpi_device_id us5182d_acpi_match[] = {
 480         { "USD5182", 0},
 481         {}
 482 };
 483
 484 MODULE_DEVICE_TABLE(acpi, us5182d_acpi_match);
 485
 486 static const struct i2c_device_id us5182d_id[] = {
 487                 {"usd5182", 0},
 488                 {}
 489 };
 490
 491 MODULE_DEVICE_TABLE(i2c, us5182d_id);
 492
 493 static struct i2c_driver us5182d_driver = {
 494         .driver = {
 495                 .name = US5182D_DRV_NAME,
 496                 .acpi_match_table = ACPI_PTR(us5182d_acpi_match),
 497         },
 498         .probe = us5182d_probe,
 499         .remove = us5182d_remove,
 500         .id_table = us5182d_id,
 501
 502 };
 503 module_i2c_driver(us5182d_driver);
 504
 505 MODULE_AUTHOR("Adriana Reus <adriana.reus@intel.com>");
 506 MODULE_DESCRIPTION("Driver for us5182d Proximity and Light Sensor");
 507 MODULE_LICENSE("GPL v2");