drivers/iio/light/noa1305.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Support for ON Semiconductor NOA1305 ambient light sensor
   4  *
   5  * Copyright (C) 2016 Emcraft Systems
   6  * Copyright (C) 2019 Collabora Ltd.
   7  */
   8
   9 #include <linux/delay.h>
  10 #include <linux/err.h>
  11 #include <linux/i2c.h>
  12 #include <linux/iio/iio.h>
  13 #include <linux/iio/sysfs.h>
  14 #include <linux/module.h>
  15 #include <linux/regmap.h>
  16 #include <linux/regulator/consumer.h>
  17
  18 #define NOA1305_REG_POWER_CONTROL       0x0
  19 #define   NOA1305_POWER_CONTROL_DOWN    0x00
  20 #define   NOA1305_POWER_CONTROL_ON      0x08
  21 #define NOA1305_REG_RESET               0x1
  22 #define   NOA1305_RESET_RESET           0x10
  23 #define NOA1305_REG_INTEGRATION_TIME    0x2
  24 #define   NOA1305_INTEGR_TIME_800MS     0x00
  25 #define   NOA1305_INTEGR_TIME_400MS     0x01
  26 #define   NOA1305_INTEGR_TIME_200MS     0x02
  27 #define   NOA1305_INTEGR_TIME_100MS     0x03
  28 #define   NOA1305_INTEGR_TIME_50MS      0x04
  29 #define   NOA1305_INTEGR_TIME_25MS      0x05
  30 #define   NOA1305_INTEGR_TIME_12_5MS    0x06
  31 #define   NOA1305_INTEGR_TIME_6_25MS    0x07
  32 #define   NOA1305_INTEGR_TIME_MASK      0x07
  33 #define NOA1305_REG_INT_SELECT          0x3
  34 #define   NOA1305_INT_SEL_ACTIVE_HIGH   0x01
  35 #define   NOA1305_INT_SEL_ACTIVE_LOW    0x02
  36 #define   NOA1305_INT_SEL_INACTIVE      0x03
  37 #define NOA1305_REG_INT_THRESH_LSB      0x4
  38 #define NOA1305_REG_INT_THRESH_MSB      0x5
  39 #define NOA1305_REG_ALS_DATA_LSB        0x6
  40 #define NOA1305_REG_ALS_DATA_MSB        0x7
  41 #define NOA1305_REG_DEVICE_ID_LSB       0x8
  42 #define NOA1305_REG_DEVICE_ID_MSB       0x9
  43
  44 #define NOA1305_DEVICE_ID       0x0519
  45 #define NOA1305_DRIVER_NAME     "noa1305"
  46
  47 static int noa1305_scale_available[] = {
  48         100, 8 * 77,            /* 800 ms */
  49         100, 4 * 77,            /* 400 ms */
  50         100, 2 * 77,            /* 200 ms */
  51         100, 1 * 77,            /* 100 ms */
  52         1000, 5 * 77,           /* 50 ms */
  53         10000, 25 * 77,         /* 25 ms */
  54         100000, 125 * 77,       /* 12.5 ms */
  55         1000000, 625 * 77,      /* 6.25 ms */
  56 };
  57
  58 static int noa1305_int_time_available[] = {
  59         0, 800000,              /* 800 ms */
  60         0, 400000,              /* 400 ms */
  61         0, 200000,              /* 200 ms */
  62         0, 100000,              /* 100 ms */
  63         0, 50000,               /* 50 ms */
  64         0, 25000,               /* 25 ms */
  65         0, 12500,               /* 12.5 ms */
  66         0, 6250,                /* 6.25 ms */
  67 };
  68
  69 struct noa1305_priv {
  70         struct i2c_client *client;
  71         struct regmap *regmap;
  72 };
  73
  74 static int noa1305_measure(struct noa1305_priv *priv, int *val)
  75 {
  76         __le16 data;
  77         int ret;
  78
  79         ret = regmap_bulk_read(priv->regmap, NOA1305_REG_ALS_DATA_LSB, &data,
  80                                2);
  81         if (ret < 0)
  82                 return ret;
  83
  84         *val = le16_to_cpu(data);
  85
  86         return IIO_VAL_INT;
  87 }
  88
  89 static int noa1305_scale(struct noa1305_priv *priv, int *val, int *val2)
  90 {
  91         int data;
  92         int ret;
  93
  94         ret = regmap_read(priv->regmap, NOA1305_REG_INTEGRATION_TIME, &data);
  95         if (ret < 0)
  96                 return ret;
  97
  98         /*
  99          * Lux = count / (<Integration Constant> * <Integration Time>)
 100          *
 101          * Integration Constant = 7.7
 102          * Integration Time in Seconds
 103          */
 104         data &= NOA1305_INTEGR_TIME_MASK;
 105         *val = noa1305_scale_available[2 * data + 0];
 106         *val2 = noa1305_scale_available[2 * data + 1];
 107
 108         return IIO_VAL_FRACTIONAL;
 109 }
 110
 111 static int noa1305_int_time(struct noa1305_priv *priv, int *val, int *val2)
 112 {
 113         int data;
 114         int ret;
 115
 116         ret = regmap_read(priv->regmap, NOA1305_REG_INTEGRATION_TIME, &data);
 117         if (ret < 0)
 118                 return ret;
 119
 120         data &= NOA1305_INTEGR_TIME_MASK;
 121         *val = noa1305_int_time_available[2 * data + 0];
 122         *val2 = noa1305_int_time_available[2 * data + 1];
 123
 124         return IIO_VAL_INT_PLUS_MICRO;
 125 }
 126
 127 static const struct iio_chan_spec noa1305_channels[] = {
 128         {
 129                 .type = IIO_LIGHT,
 130                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 131                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
 132                 .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SCALE),
 133                 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
 134                 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME),
 135         }
 136 };
 137
 138 static int noa1305_read_avail(struct iio_dev *indio_dev,
 139                               struct iio_chan_spec const *chan,
 140                               const int **vals, int *type,
 141                               int *length, long mask)
 142 {
 143         if (chan->type != IIO_LIGHT)
 144                 return -EINVAL;
 145
 146         switch (mask) {
 147         case IIO_CHAN_INFO_SCALE:
 148                 *vals = noa1305_scale_available;
 149                 *length = ARRAY_SIZE(noa1305_scale_available);
 150                 *type = IIO_VAL_FRACTIONAL;
 151                 return IIO_AVAIL_LIST;
 152         case IIO_CHAN_INFO_INT_TIME:
 153                 *vals = noa1305_int_time_available;
 154                 *length = ARRAY_SIZE(noa1305_int_time_available);
 155                 *type = IIO_VAL_INT_PLUS_MICRO;
 156                 return IIO_AVAIL_LIST;
 157         default:
 158                 return -EINVAL;
 159         }
 160 }
 161
 162 static int noa1305_read_raw(struct iio_dev *indio_dev,
 163                             struct iio_chan_spec const *chan,
 164                             int *val, int *val2, long mask)
 165 {
 166         struct noa1305_priv *priv = iio_priv(indio_dev);
 167
 168         if (chan->type != IIO_LIGHT)
 169                 return -EINVAL;
 170
 171         switch (mask) {
 172         case IIO_CHAN_INFO_RAW:
 173                 return noa1305_measure(priv, val);
 174         case IIO_CHAN_INFO_SCALE:
 175                 return noa1305_scale(priv, val, val2);
 176         case IIO_CHAN_INFO_INT_TIME:
 177                 return noa1305_int_time(priv, val, val2);
 178         default:
 179                 return -EINVAL;
 180         }
 181 }
 182
 183 static int noa1305_write_raw(struct iio_dev *indio_dev,
 184                              struct iio_chan_spec const *chan,
 185                              int val, int val2, long mask)
 186 {
 187         struct noa1305_priv *priv = iio_priv(indio_dev);
 188         int i;
 189
 190         if (chan->type != IIO_LIGHT)
 191                 return -EINVAL;
 192
 193         if (mask != IIO_CHAN_INFO_INT_TIME)
 194                 return -EINVAL;
 195
 196         if (val)        /* >= 1s integration time not supported */
 197                 return -EINVAL;
 198
 199         /* Look up integration time register settings and write it if found. */
 200         for (i = 0; i < ARRAY_SIZE(noa1305_int_time_available) / 2; i++)
 201                 if (noa1305_int_time_available[2 * i + 1] == val2)
 202                         return regmap_write(priv->regmap, NOA1305_REG_INTEGRATION_TIME, i);
 203
 204         return -EINVAL;
 205 }
 206
 207 static const struct iio_info noa1305_info = {
 208         .read_avail = noa1305_read_avail,
 209         .read_raw = noa1305_read_raw,
 210         .write_raw = noa1305_write_raw,
 211 };
 212
 213 static bool noa1305_writable_reg(struct device *dev, unsigned int reg)
 214 {
 215         switch (reg) {
 216         case NOA1305_REG_POWER_CONTROL:
 217         case NOA1305_REG_RESET:
 218         case NOA1305_REG_INTEGRATION_TIME:
 219         case NOA1305_REG_INT_SELECT:
 220         case NOA1305_REG_INT_THRESH_LSB:
 221         case NOA1305_REG_INT_THRESH_MSB:
 222                 return true;
 223         default:
 224                 return false;
 225         }
 226 }
 227
 228 static const struct regmap_config noa1305_regmap_config = {
 229         .name = NOA1305_DRIVER_NAME,
 230         .reg_bits = 8,
 231         .val_bits = 8,
 232         .max_register = NOA1305_REG_DEVICE_ID_MSB,
 233         .writeable_reg = noa1305_writable_reg,
 234 };
 235
 236 static int noa1305_probe(struct i2c_client *client)
 237 {
 238         struct noa1305_priv *priv;
 239         struct iio_dev *indio_dev;
 240         struct regmap *regmap;
 241         __le16 data;
 242         unsigned int dev_id;
 243         int ret;
 244
 245         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*priv));
 246         if (!indio_dev)
 247                 return -ENOMEM;
 248
 249         regmap = devm_regmap_init_i2c(client, &noa1305_regmap_config);
 250         if (IS_ERR(regmap)) {
 251                 dev_err(&client->dev, "Regmap initialization failed.\n");
 252                 return PTR_ERR(regmap);
 253         }
 254
 255         priv = iio_priv(indio_dev);
 256
 257         ret = devm_regulator_get_enable(&client->dev, "vin");
 258         if (ret)
 259                 return dev_err_probe(&client->dev, ret,
 260                                      "get regulator vin failed\n");
 261
 262         i2c_set_clientdata(client, indio_dev);
 263         priv->client = client;
 264         priv->regmap = regmap;
 265
 266         ret = regmap_bulk_read(regmap, NOA1305_REG_DEVICE_ID_LSB, &data, 2);
 267         if (ret < 0) {
 268                 dev_err(&client->dev, "ID reading failed: %d\n", ret);
 269                 return ret;
 270         }
 271
 272         dev_id = le16_to_cpu(data);
 273         if (dev_id != NOA1305_DEVICE_ID) {
 274                 dev_err(&client->dev, "Unknown device ID: 0x%x\n", dev_id);
 275                 return -ENODEV;
 276         }
 277
 278         ret = regmap_write(regmap, NOA1305_REG_POWER_CONTROL,
 279                            NOA1305_POWER_CONTROL_ON);
 280         if (ret < 0) {
 281                 dev_err(&client->dev, "Enabling power control failed\n");
 282                 return ret;
 283         }
 284
 285         ret = regmap_write(regmap, NOA1305_REG_RESET, NOA1305_RESET_RESET);
 286         if (ret < 0) {
 287                 dev_err(&client->dev, "Device reset failed\n");
 288                 return ret;
 289         }
 290
 291         ret = regmap_write(regmap, NOA1305_REG_INTEGRATION_TIME,
 292                            NOA1305_INTEGR_TIME_800MS);
 293         if (ret < 0) {
 294                 dev_err(&client->dev, "Setting integration time failed\n");
 295                 return ret;
 296         }
 297
 298         indio_dev->info = &noa1305_info;
 299         indio_dev->channels = noa1305_channels;
 300         indio_dev->num_channels = ARRAY_SIZE(noa1305_channels);
 301         indio_dev->name = NOA1305_DRIVER_NAME;
 302         indio_dev->modes = INDIO_DIRECT_MODE;
 303
 304         ret = devm_iio_device_register(&client->dev, indio_dev);
 305         if (ret)
 306                 dev_err(&client->dev, "registering device failed\n");
 307
 308         return ret;
 309 }
 310
 311 static const struct of_device_id noa1305_of_match[] = {
 312         { .compatible = "onnn,noa1305" },
 313         { }
 314 };
 315 MODULE_DEVICE_TABLE(of, noa1305_of_match);
 316
 317 static const struct i2c_device_id noa1305_ids[] = {
 318         { "noa1305" },
 319         { }
 320 };
 321 MODULE_DEVICE_TABLE(i2c, noa1305_ids);
 322
 323 static struct i2c_driver noa1305_driver = {
 324         .driver = {
 325                 .name           = NOA1305_DRIVER_NAME,
 326                 .of_match_table = noa1305_of_match,
 327         },
 328         .probe          = noa1305_probe,
 329         .id_table       = noa1305_ids,
 330 };
 331
 332 module_i2c_driver(noa1305_driver);
 333
 334 MODULE_AUTHOR("Sergei Miroshnichenko <sergeimir@emcraft.com>");
 335 MODULE_AUTHOR("Martyn Welch <martyn.welch@collabora.com");
 336 MODULE_DESCRIPTION("ON Semiconductor NOA1305 ambient light sensor");
 337 MODULE_LICENSE("GPL");