drivers/iio/light/cm3232.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * CM3232 Ambient Light Sensor
   4  *
   5  * Copyright (C) 2014-2015 Capella Microsystems Inc.
   6  * Author: Kevin Tsai <ktsai@capellamicro.com>
   7  *
   8  * IIO driver for CM3232 (7-bit I2C slave address 0x10).
   9  */
  10
  11 #include <linux/i2c.h>
  12 #include <linux/module.h>
  13 #include <linux/mod_devicetable.h>
  14 #include <linux/iio/iio.h>
  15 #include <linux/iio/sysfs.h>
  16 #include <linux/init.h>
  17
  18 /* Registers Address */
  19 #define CM3232_REG_ADDR_CMD             0x00
  20 #define CM3232_REG_ADDR_ALS             0x50
  21 #define CM3232_REG_ADDR_ID              0x53
  22
  23 #define CM3232_CMD_ALS_DISABLE          BIT(0)
  24
  25 #define CM3232_CMD_ALS_IT_SHIFT         2
  26 #define CM3232_CMD_ALS_IT_MASK          (BIT(2) | BIT(3) | BIT(4))
  27 #define CM3232_CMD_ALS_IT_DEFAULT       (0x01 << CM3232_CMD_ALS_IT_SHIFT)
  28
  29 #define CM3232_CMD_ALS_RESET            BIT(6)
  30
  31 #define CM3232_CMD_DEFAULT              CM3232_CMD_ALS_IT_DEFAULT
  32
  33 #define CM3232_HW_ID                    0x32
  34 #define CM3232_CALIBSCALE_DEFAULT       100000
  35 #define CM3232_CALIBSCALE_RESOLUTION    100000
  36 #define CM3232_MLUX_PER_LUX             1000
  37
  38 #define CM3232_MLUX_PER_BIT_DEFAULT     64
  39 #define CM3232_MLUX_PER_BIT_BASE_IT     100000
  40
  41 static const struct {
  42         int val;
  43         int val2;
  44         u8 it;
  45 } cm3232_als_it_scales[] = {
  46         {0, 100000, 0}, /* 0.100000 */
  47         {0, 200000, 1}, /* 0.200000 */
  48         {0, 400000, 2}, /* 0.400000 */
  49         {0, 800000, 3}, /* 0.800000 */
  50         {1, 600000, 4}, /* 1.600000 */
  51         {3, 200000, 5}, /* 3.200000 */
  52 };
  53
  54 struct cm3232_als_info {
  55         u8 regs_cmd_default;
  56         u8 hw_id;
  57         int calibscale;
  58         int mlux_per_bit;
  59         int mlux_per_bit_base_it;
  60 };
  61
  62 static struct cm3232_als_info cm3232_als_info_default = {
  63         .regs_cmd_default = CM3232_CMD_DEFAULT,
  64         .hw_id = CM3232_HW_ID,
  65         .calibscale = CM3232_CALIBSCALE_DEFAULT,
  66         .mlux_per_bit = CM3232_MLUX_PER_BIT_DEFAULT,
  67         .mlux_per_bit_base_it = CM3232_MLUX_PER_BIT_BASE_IT,
  68 };
  69
  70 struct cm3232_chip {
  71         struct i2c_client *client;
  72         struct cm3232_als_info *als_info;
  73         u8 regs_cmd;
  74         u16 regs_als;
  75 };
  76
  77 /**
  78  * cm3232_reg_init() - Initialize CM3232
  79  * @chip:       pointer of struct cm3232_chip.
  80  *
  81  * Check and initialize CM3232 ambient light sensor.
  82  *
  83  * Return: 0 for success; otherwise for error code.
  84  */
  85 static int cm3232_reg_init(struct cm3232_chip *chip)
  86 {
  87         struct i2c_client *client = chip->client;
  88         s32 ret;
  89
  90         chip->als_info = &cm3232_als_info_default;
  91
  92         /* Identify device */
  93         ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ID);
  94         if (ret < 0) {
  95                 dev_err(&chip->client->dev, "Error reading addr_id\n");
  96                 return ret;
  97         }
  98
  99         if ((ret & 0xFF) != chip->als_info->hw_id)
 100                 return -ENODEV;
 101
 102         /* Disable and reset device */
 103         chip->regs_cmd = CM3232_CMD_ALS_DISABLE | CM3232_CMD_ALS_RESET;
 104         ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
 105                                         chip->regs_cmd);
 106         if (ret < 0) {
 107                 dev_err(&chip->client->dev, "Error writing reg_cmd\n");
 108                 return ret;
 109         }
 110
 111         /* Register default value */
 112         chip->regs_cmd = chip->als_info->regs_cmd_default;
 113
 114         /* Configure register */
 115         ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
 116                                         chip->regs_cmd);
 117         if (ret < 0)
 118                 dev_err(&chip->client->dev, "Error writing reg_cmd\n");
 119
 120         return ret;
 121 }
 122
 123 /**
 124  *  cm3232_read_als_it() - Get sensor integration time
 125  *  @chip:      pointer of struct cm3232_chip
 126  *  @val:       pointer of int to load the integration (sec).
 127  *  @val2:      pointer of int to load the integration time (microsecond).
 128  *
 129  *  Report the current integration time.
 130  *
 131  *  Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
 132  */
 133 static int cm3232_read_als_it(struct cm3232_chip *chip, int *val, int *val2)
 134 {
 135         u16 als_it;
 136         int i;
 137
 138         als_it = chip->regs_cmd;
 139         als_it &= CM3232_CMD_ALS_IT_MASK;
 140         als_it >>= CM3232_CMD_ALS_IT_SHIFT;
 141         for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {
 142                 if (als_it == cm3232_als_it_scales[i].it) {
 143                         *val = cm3232_als_it_scales[i].val;
 144                         *val2 = cm3232_als_it_scales[i].val2;
 145                         return IIO_VAL_INT_PLUS_MICRO;
 146                 }
 147         }
 148
 149         return -EINVAL;
 150 }
 151
 152 /**
 153  * cm3232_write_als_it() - Write sensor integration time
 154  * @chip:       pointer of struct cm3232_chip.
 155  * @val:        integration time in second.
 156  * @val2:       integration time in microsecond.
 157  *
 158  * Convert integration time to sensor value.
 159  *
 160  * Return: i2c_smbus_write_byte_data command return value.
 161  */
 162 static int cm3232_write_als_it(struct cm3232_chip *chip, int val, int val2)
 163 {
 164         struct i2c_client *client = chip->client;
 165         u16 als_it, cmd;
 166         int i;
 167         s32 ret;
 168
 169         for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {
 170                 if (val == cm3232_als_it_scales[i].val &&
 171                         val2 == cm3232_als_it_scales[i].val2) {
 172
 173                         als_it = cm3232_als_it_scales[i].it;
 174                         als_it <<= CM3232_CMD_ALS_IT_SHIFT;
 175
 176                         cmd = chip->regs_cmd & ~CM3232_CMD_ALS_IT_MASK;
 177                         cmd |= als_it;
 178                         ret = i2c_smbus_write_byte_data(client,
 179                                                         CM3232_REG_ADDR_CMD,
 180                                                         cmd);
 181                         if (ret < 0)
 182                                 return ret;
 183                         chip->regs_cmd = cmd;
 184                         return 0;
 185                 }
 186         }
 187         return -EINVAL;
 188 }
 189
 190 /**
 191  * cm3232_get_lux() - report current lux value
 192  * @chip:       pointer of struct cm3232_chip.
 193  *
 194  * Convert sensor data to lux.  It depends on integration
 195  * time and calibscale variable.
 196  *
 197  * Return: Zero or positive value is lux, otherwise error code.
 198  */
 199 static int cm3232_get_lux(struct cm3232_chip *chip)
 200 {
 201         struct i2c_client *client = chip->client;
 202         struct cm3232_als_info *als_info = chip->als_info;
 203         int ret;
 204         int val, val2;
 205         int als_it;
 206         u64 lux;
 207
 208         /* Calculate mlux per bit based on als_it */
 209         ret = cm3232_read_als_it(chip, &val, &val2);
 210         if (ret < 0)
 211                 return -EINVAL;
 212         als_it = val * 1000000 + val2;
 213         lux = (__force u64)als_info->mlux_per_bit;
 214         lux *= als_info->mlux_per_bit_base_it;
 215         lux = div_u64(lux, als_it);
 216
 217         ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ALS);
 218         if (ret < 0) {
 219                 dev_err(&client->dev, "Error reading reg_addr_als\n");
 220                 return ret;
 221         }
 222
 223         chip->regs_als = (u16)ret;
 224         lux *= chip->regs_als;
 225         lux *= als_info->calibscale;
 226         lux = div_u64(lux, CM3232_CALIBSCALE_RESOLUTION);
 227         lux = div_u64(lux, CM3232_MLUX_PER_LUX);
 228
 229         if (lux > 0xFFFF)
 230                 lux = 0xFFFF;
 231
 232         return (int)lux;
 233 }
 234
 235 static int cm3232_read_raw(struct iio_dev *indio_dev,
 236                         struct iio_chan_spec const *chan,
 237                         int *val, int *val2, long mask)
 238 {
 239         struct cm3232_chip *chip = iio_priv(indio_dev);
 240         struct cm3232_als_info *als_info = chip->als_info;
 241         int ret;
 242
 243         switch (mask) {
 244         case IIO_CHAN_INFO_PROCESSED:
 245                 ret = cm3232_get_lux(chip);
 246                 if (ret < 0)
 247                         return ret;
 248                 *val = ret;
 249                 return IIO_VAL_INT;
 250         case IIO_CHAN_INFO_CALIBSCALE:
 251                 *val = als_info->calibscale;
 252                 return IIO_VAL_INT;
 253         case IIO_CHAN_INFO_INT_TIME:
 254                 return cm3232_read_als_it(chip, val, val2);
 255         }
 256
 257         return -EINVAL;
 258 }
 259
 260 static int cm3232_write_raw(struct iio_dev *indio_dev,
 261                         struct iio_chan_spec const *chan,
 262                         int val, int val2, long mask)
 263 {
 264         struct cm3232_chip *chip = iio_priv(indio_dev);
 265         struct cm3232_als_info *als_info = chip->als_info;
 266
 267         switch (mask) {
 268         case IIO_CHAN_INFO_CALIBSCALE:
 269                 als_info->calibscale = val;
 270                 return 0;
 271         case IIO_CHAN_INFO_INT_TIME:
 272                 return cm3232_write_als_it(chip, val, val2);
 273         }
 274
 275         return -EINVAL;
 276 }
 277
 278 /**
 279  * cm3232_get_it_available() - Get available ALS IT value
 280  * @dev:        pointer of struct device.
 281  * @attr:       pointer of struct device_attribute.
 282  * @buf:        pointer of return string buffer.
 283  *
 284  * Display the available integration time in second.
 285  *
 286  * Return: string length.
 287  */
 288 static ssize_t cm3232_get_it_available(struct device *dev,
 289                         struct device_attribute *attr, char *buf)
 290 {
 291         int i, len;
 292
 293         for (i = 0, len = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++)
 294                 len += scnprintf(buf + len, PAGE_SIZE - len, "%u.%06u ",
 295                         cm3232_als_it_scales[i].val,
 296                         cm3232_als_it_scales[i].val2);
 297         return len + scnprintf(buf + len, PAGE_SIZE - len, "\n");
 298 }
 299
 300 static const struct iio_chan_spec cm3232_channels[] = {
 301         {
 302                 .type = IIO_LIGHT,
 303                 .info_mask_separate =
 304                         BIT(IIO_CHAN_INFO_PROCESSED) |
 305                         BIT(IIO_CHAN_INFO_CALIBSCALE) |
 306                         BIT(IIO_CHAN_INFO_INT_TIME),
 307         }
 308 };
 309
 310 static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
 311                         S_IRUGO, cm3232_get_it_available, NULL, 0);
 312
 313 static struct attribute *cm3232_attributes[] = {
 314         &iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
 315         NULL,
 316 };
 317
 318 static const struct attribute_group cm3232_attribute_group = {
 319         .attrs = cm3232_attributes
 320 };
 321
 322 static const struct iio_info cm3232_info = {
 323         .read_raw               = &cm3232_read_raw,
 324         .write_raw              = &cm3232_write_raw,
 325         .attrs                  = &cm3232_attribute_group,
 326 };
 327
 328 static int cm3232_probe(struct i2c_client *client,
 329                         const struct i2c_device_id *id)
 330 {
 331         struct cm3232_chip *chip;
 332         struct iio_dev *indio_dev;
 333         int ret;
 334
 335         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
 336         if (!indio_dev)
 337                 return -ENOMEM;
 338
 339         chip = iio_priv(indio_dev);
 340         i2c_set_clientdata(client, indio_dev);
 341         chip->client = client;
 342
 343         indio_dev->channels = cm3232_channels;
 344         indio_dev->num_channels = ARRAY_SIZE(cm3232_channels);
 345         indio_dev->info = &cm3232_info;
 346         indio_dev->name = id->name;
 347         indio_dev->modes = INDIO_DIRECT_MODE;
 348
 349         ret = cm3232_reg_init(chip);
 350         if (ret) {
 351                 dev_err(&client->dev,
 352                         "%s: register init failed\n",
 353                         __func__);
 354                 return ret;
 355         }
 356
 357         return iio_device_register(indio_dev);
 358 }
 359
 360 static int cm3232_remove(struct i2c_client *client)
 361 {
 362         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 363
 364         i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
 365                 CM3232_CMD_ALS_DISABLE);
 366
 367         iio_device_unregister(indio_dev);
 368
 369         return 0;
 370 }
 371
 372 static const struct i2c_device_id cm3232_id[] = {
 373         {"cm3232", 0},
 374         {}
 375 };
 376
 377 #ifdef CONFIG_PM_SLEEP
 378 static int cm3232_suspend(struct device *dev)
 379 {
 380         struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
 381         struct cm3232_chip *chip = iio_priv(indio_dev);
 382         struct i2c_client *client = chip->client;
 383         int ret;
 384
 385         chip->regs_cmd |= CM3232_CMD_ALS_DISABLE;
 386         ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
 387                                         chip->regs_cmd);
 388
 389         return ret;
 390 }
 391
 392 static int cm3232_resume(struct device *dev)
 393 {
 394         struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
 395         struct cm3232_chip *chip = iio_priv(indio_dev);
 396         struct i2c_client *client = chip->client;
 397         int ret;
 398
 399         chip->regs_cmd &= ~CM3232_CMD_ALS_DISABLE;
 400         ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
 401                                         chip->regs_cmd | CM3232_CMD_ALS_RESET);
 402
 403         return ret;
 404 }
 405
 406 static const struct dev_pm_ops cm3232_pm_ops = {
 407         SET_SYSTEM_SLEEP_PM_OPS(cm3232_suspend, cm3232_resume)};
 408 #endif
 409
 410 MODULE_DEVICE_TABLE(i2c, cm3232_id);
 411
 412 static const struct of_device_id cm3232_of_match[] = {
 413         {.compatible = "capella,cm3232"},
 414         {}
 415 };
 416 MODULE_DEVICE_TABLE(of, cm3232_of_match);
 417
 418 static struct i2c_driver cm3232_driver = {
 419         .driver = {
 420                 .name   = "cm3232",
 421                 .of_match_table = cm3232_of_match,
 422 #ifdef CONFIG_PM_SLEEP
 423                 .pm     = &cm3232_pm_ops,
 424 #endif
 425         },
 426         .id_table       = cm3232_id,
 427         .probe          = cm3232_probe,
 428         .remove         = cm3232_remove,
 429 };
 430
 431 module_i2c_driver(cm3232_driver);
 432
 433 MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
 434 MODULE_DESCRIPTION("CM3232 ambient light sensor driver");
 435 MODULE_LICENSE("GPL");