drivers/iio/light/cm3323.c

   1 /*
   2  * CM3323 - Capella Color Light Sensor
   3  *
   4  * Copyright (c) 2015, Intel Corporation.
   5  *
   6  * This file is subject to the terms and conditions of version 2 of
   7  * the GNU General Public License.  See the file COPYING in the main
   8  * directory of this archive for more details.
   9  *
  10  * IIO driver for CM3323 (7-bit I2C slave address 0x10)
  11  *
  12  * TODO: calibscale to correct the lens factor
  13  */
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/i2c.h>
  17 #include <linux/mutex.h>
  18
  19 #include <linux/iio/iio.h>
  20 #include <linux/iio/sysfs.h>
  21
  22 #define CM3323_DRV_NAME "cm3323"
  23
  24 #define CM3323_CMD_CONF         0x00
  25 #define CM3323_CMD_RED_DATA     0x08
  26 #define CM3323_CMD_GREEN_DATA   0x09
  27 #define CM3323_CMD_BLUE_DATA    0x0A
  28 #define CM3323_CMD_CLEAR_DATA   0x0B
  29
  30 #define CM3323_CONF_SD_BIT      BIT(0) /* sensor disable */
  31 #define CM3323_CONF_AF_BIT      BIT(1) /* auto/manual force mode */
  32 #define CM3323_CONF_IT_MASK     (BIT(4) | BIT(5) | BIT(6))
  33 #define CM3323_CONF_IT_SHIFT    4
  34
  35 #define CM3323_INT_TIME_AVAILABLE "0.04 0.08 0.16 0.32 0.64 1.28"
  36
  37 static const struct {
  38         int val;
  39         int val2;
  40 } cm3323_int_time[] = {
  41         {0, 40000},  /* 40 ms */
  42         {0, 80000},  /* 80 ms */
  43         {0, 160000}, /* 160 ms */
  44         {0, 320000}, /* 320 ms */
  45         {0, 640000}, /* 640 ms */
  46         {1, 280000}, /* 1280 ms */
  47 };
  48
  49 struct cm3323_data {
  50         struct i2c_client *client;
  51         u16 reg_conf;
  52         struct mutex mutex;
  53 };
  54
  55 #define CM3323_COLOR_CHANNEL(_color, _addr) { \
  56         .type = IIO_INTENSITY, \
  57         .modified = 1, \
  58         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
  59         .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), \
  60         .channel2 = IIO_MOD_LIGHT_##_color, \
  61         .address = _addr, \
  62 }
  63
  64 static const struct iio_chan_spec cm3323_channels[] = {
  65         CM3323_COLOR_CHANNEL(RED, CM3323_CMD_RED_DATA),
  66         CM3323_COLOR_CHANNEL(GREEN, CM3323_CMD_GREEN_DATA),
  67         CM3323_COLOR_CHANNEL(BLUE, CM3323_CMD_BLUE_DATA),
  68         CM3323_COLOR_CHANNEL(CLEAR, CM3323_CMD_CLEAR_DATA),
  69 };
  70
  71 static IIO_CONST_ATTR_INT_TIME_AVAIL(CM3323_INT_TIME_AVAILABLE);
  72
  73 static struct attribute *cm3323_attributes[] = {
  74         &iio_const_attr_integration_time_available.dev_attr.attr,
  75         NULL
  76 };
  77
  78 static const struct attribute_group cm3323_attribute_group = {
  79         .attrs = cm3323_attributes,
  80 };
  81
  82 static int cm3323_init(struct iio_dev *indio_dev)
  83 {
  84         int ret;
  85         struct cm3323_data *data = iio_priv(indio_dev);
  86
  87         ret = i2c_smbus_read_word_data(data->client, CM3323_CMD_CONF);
  88         if (ret < 0) {
  89                 dev_err(&data->client->dev, "Error reading reg_conf\n");
  90                 return ret;
  91         }
  92
  93         /* enable sensor and set auto force mode */
  94         ret &= ~(CM3323_CONF_SD_BIT | CM3323_CONF_AF_BIT);
  95
  96         ret = i2c_smbus_write_word_data(data->client, CM3323_CMD_CONF, ret);
  97         if (ret < 0) {
  98                 dev_err(&data->client->dev, "Error writing reg_conf\n");
  99                 return ret;
 100         }
 101
 102         data->reg_conf = ret;
 103
 104         return 0;
 105 }
 106
 107 static void cm3323_disable(struct iio_dev *indio_dev)
 108 {
 109         int ret;
 110         struct cm3323_data *data = iio_priv(indio_dev);
 111
 112         ret = i2c_smbus_write_word_data(data->client, CM3323_CMD_CONF,
 113                                         CM3323_CONF_SD_BIT);
 114         if (ret < 0)
 115                 dev_err(&data->client->dev, "Error writing reg_conf\n");
 116 }
 117
 118 static int cm3323_set_it_bits(struct cm3323_data *data, int val, int val2)
 119 {
 120         int i, ret;
 121         u16 reg_conf;
 122
 123         for (i = 0; i < ARRAY_SIZE(cm3323_int_time); i++) {
 124                 if (val == cm3323_int_time[i].val &&
 125                     val2 == cm3323_int_time[i].val2) {
 126                         reg_conf = data->reg_conf & ~CM3323_CONF_IT_MASK;
 127                         reg_conf |= i << CM3323_CONF_IT_SHIFT;
 128
 129                         ret = i2c_smbus_write_word_data(data->client,
 130                                                         CM3323_CMD_CONF,
 131                                                         reg_conf);
 132                         if (ret < 0)
 133                                 return ret;
 134
 135                         data->reg_conf = reg_conf;
 136                         return 0;
 137                 }
 138         }
 139         return -EINVAL;
 140 }
 141
 142 static int cm3323_get_it_bits(struct cm3323_data *data)
 143 {
 144         int bits;
 145
 146         bits = (data->reg_conf & CM3323_CONF_IT_MASK) >>
 147                 CM3323_CONF_IT_SHIFT;
 148
 149         if (bits >= ARRAY_SIZE(cm3323_int_time))
 150                 return -EINVAL;
 151         return bits;
 152 }
 153
 154 static int cm3323_read_raw(struct iio_dev *indio_dev,
 155                            struct iio_chan_spec const *chan, int *val,
 156                            int *val2, long mask)
 157 {
 158         int i, ret;
 159         struct cm3323_data *data = iio_priv(indio_dev);
 160
 161         switch (mask) {
 162         case IIO_CHAN_INFO_RAW:
 163                 mutex_lock(&data->mutex);
 164                 ret = i2c_smbus_read_word_data(data->client, chan->address);
 165                 if (ret < 0) {
 166                         mutex_unlock(&data->mutex);
 167                         return ret;
 168                 }
 169                 *val = ret;
 170                 mutex_unlock(&data->mutex);
 171
 172                 return IIO_VAL_INT;
 173         case IIO_CHAN_INFO_INT_TIME:
 174                 mutex_lock(&data->mutex);
 175                 i = cm3323_get_it_bits(data);
 176                 if (i < 0) {
 177                         mutex_unlock(&data->mutex);
 178                         return -EINVAL;
 179                 }
 180
 181                 *val = cm3323_int_time[i].val;
 182                 *val2 = cm3323_int_time[i].val2;
 183                 mutex_unlock(&data->mutex);
 184
 185                 return IIO_VAL_INT_PLUS_MICRO;
 186         default:
 187                 return -EINVAL;
 188         }
 189 }
 190
 191 static int cm3323_write_raw(struct iio_dev *indio_dev,
 192                             struct iio_chan_spec const *chan, int val,
 193                             int val2, long mask)
 194 {
 195         struct cm3323_data *data = iio_priv(indio_dev);
 196         int ret;
 197
 198         switch (mask) {
 199         case IIO_CHAN_INFO_INT_TIME:
 200                 mutex_lock(&data->mutex);
 201                 ret = cm3323_set_it_bits(data, val, val2);
 202                 mutex_unlock(&data->mutex);
 203
 204                 return ret;
 205         default:
 206                 return -EINVAL;
 207         }
 208 }
 209
 210 static const struct iio_info cm3323_info = {
 211         .driver_module  = THIS_MODULE,
 212         .read_raw       = cm3323_read_raw,
 213         .write_raw      = cm3323_write_raw,
 214         .attrs          = &cm3323_attribute_group,
 215 };
 216
 217 static int cm3323_probe(struct i2c_client *client,
 218                         const struct i2c_device_id *id)
 219 {
 220         struct cm3323_data *data;
 221         struct iio_dev *indio_dev;
 222         int ret;
 223
 224         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 225         if (!indio_dev)
 226                 return -ENOMEM;
 227
 228         data = iio_priv(indio_dev);
 229         i2c_set_clientdata(client, indio_dev);
 230         data->client = client;
 231
 232         mutex_init(&data->mutex);
 233
 234         indio_dev->dev.parent = &client->dev;
 235         indio_dev->info = &cm3323_info;
 236         indio_dev->name = CM3323_DRV_NAME;
 237         indio_dev->channels = cm3323_channels;
 238         indio_dev->num_channels = ARRAY_SIZE(cm3323_channels);
 239         indio_dev->modes = INDIO_DIRECT_MODE;
 240
 241         ret = cm3323_init(indio_dev);
 242         if (ret < 0) {
 243                 dev_err(&client->dev, "cm3323 chip init failed\n");
 244                 return ret;
 245         }
 246         ret = iio_device_register(indio_dev);
 247         if (ret < 0) {
 248                 dev_err(&client->dev, "failed to register iio dev\n");
 249                 goto err_init;
 250         }
 251         return 0;
 252 err_init:
 253         cm3323_disable(indio_dev);
 254         return ret;
 255 }
 256
 257 static int cm3323_remove(struct i2c_client *client)
 258 {
 259         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 260
 261         iio_device_unregister(indio_dev);
 262         cm3323_disable(indio_dev);
 263
 264         return 0;
 265 }
 266
 267 static const struct i2c_device_id cm3323_id[] = {
 268         {"cm3323", 0},
 269         {}
 270 };
 271 MODULE_DEVICE_TABLE(i2c, cm3323_id);
 272
 273 static struct i2c_driver cm3323_driver = {
 274         .driver = {
 275                 .name = CM3323_DRV_NAME,
 276         },
 277         .probe          = cm3323_probe,
 278         .remove         = cm3323_remove,
 279         .id_table       = cm3323_id,
 280 };
 281
 282 module_i2c_driver(cm3323_driver);
 283
 284 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
 285 MODULE_DESCRIPTION("Capella CM3323 Color Light Sensor driver");
 286 MODULE_LICENSE("GPL v2");