drivers/iio/light/tsl4531.c

   1 /*
   2  * tsl4531.c - Support for TAOS TSL4531 ambient light sensor
   3  *
   4  * Copyright 2013 Peter Meerwald <pmeerw@pmeerw.net>
   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 the TSL4531x family
  11  *   TSL45311/TSL45313: 7-bit I2C slave address 0x39
  12  *   TSL45315/TSL45317: 7-bit I2C slave address 0x29
  13  *
  14  * TODO: single cycle measurement
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/i2c.h>
  19 #include <linux/err.h>
  20 #include <linux/delay.h>
  21
  22 #include <linux/iio/iio.h>
  23 #include <linux/iio/sysfs.h>
  24
  25 #define TSL4531_DRV_NAME "tsl4531"
  26
  27 #define TSL4531_COMMAND BIT(7)
  28
  29 #define TSL4531_CONTROL (TSL4531_COMMAND | 0x00)
  30 #define TSL4531_CONFIG (TSL4531_COMMAND | 0x01)
  31 #define TSL4531_DATA (TSL4531_COMMAND | 0x04)
  32 #define TSL4531_ID (TSL4531_COMMAND | 0x0a)
  33
  34 /* operating modes in control register */
  35 #define TSL4531_MODE_POWERDOWN 0x00
  36 #define TSL4531_MODE_SINGLE_ADC 0x02
  37 #define TSL4531_MODE_NORMAL 0x03
  38
  39 /* integration time control in config register */
  40 #define TSL4531_TCNTRL_400MS 0x00
  41 #define TSL4531_TCNTRL_200MS 0x01
  42 #define TSL4531_TCNTRL_100MS 0x02
  43
  44 /* part number in id register */
  45 #define TSL45311_ID 0x8
  46 #define TSL45313_ID 0x9
  47 #define TSL45315_ID 0xa
  48 #define TSL45317_ID 0xb
  49 #define TSL4531_ID_SHIFT 4
  50
  51 struct tsl4531_data {
  52         struct i2c_client *client;
  53         struct mutex lock;
  54         int int_time;
  55 };
  56
  57 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.1 0.2 0.4");
  58
  59 static struct attribute *tsl4531_attributes[] = {
  60         &iio_const_attr_integration_time_available.dev_attr.attr,
  61         NULL
  62 };
  63
  64 static const struct attribute_group tsl4531_attribute_group = {
  65         .attrs = tsl4531_attributes,
  66 };
  67
  68 static const struct iio_chan_spec tsl4531_channels[] = {
  69         {
  70                 .type = IIO_LIGHT,
  71                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
  72                         BIT(IIO_CHAN_INFO_SCALE) |
  73                         BIT(IIO_CHAN_INFO_INT_TIME)
  74         }
  75 };
  76
  77 static int tsl4531_read_raw(struct iio_dev *indio_dev,
  78                                 struct iio_chan_spec const *chan,
  79                                 int *val, int *val2, long mask)
  80 {
  81         struct tsl4531_data *data = iio_priv(indio_dev);
  82         int ret;
  83
  84         switch (mask) {
  85         case IIO_CHAN_INFO_RAW:
  86                 ret = i2c_smbus_read_word_data(data->client,
  87                         TSL4531_DATA);
  88                 if (ret < 0)
  89                         return ret;
  90                 *val = ret;
  91                 return IIO_VAL_INT;
  92         case IIO_CHAN_INFO_SCALE:
  93                 /* 0.. 1x, 1 .. 2x, 2 .. 4x */
  94                 *val = 1 << data->int_time;
  95                 return IIO_VAL_INT;
  96         case IIO_CHAN_INFO_INT_TIME:
  97                 if (data->int_time == 0)
  98                         *val2 = 400000;
  99                 else if (data->int_time == 1)
 100                         *val2 = 200000;
 101                 else if (data->int_time == 2)
 102                         *val2 = 100000;
 103                 else
 104                         return -EINVAL;
 105                 *val = 0;
 106                 return IIO_VAL_INT_PLUS_MICRO;
 107         default:
 108                 return -EINVAL;
 109         }
 110 }
 111
 112 static int tsl4531_write_raw(struct iio_dev *indio_dev,
 113                              struct iio_chan_spec const *chan,
 114                              int val, int val2, long mask)
 115 {
 116         struct tsl4531_data *data = iio_priv(indio_dev);
 117         int int_time, ret;
 118
 119         switch (mask) {
 120         case IIO_CHAN_INFO_INT_TIME:
 121                 if (val != 0)
 122                         return -EINVAL;
 123                 if (val2 == 400000)
 124                         int_time = 0;
 125                 else if (val2 == 200000)
 126                         int_time = 1;
 127                 else if (val2 == 100000)
 128                         int_time = 2;
 129                 else
 130                         return -EINVAL;
 131                 mutex_lock(&data->lock);
 132                 ret = i2c_smbus_write_byte_data(data->client,
 133                         TSL4531_CONFIG, int_time);
 134                 if (ret >= 0)
 135                         data->int_time = int_time;
 136                 mutex_unlock(&data->lock);
 137                 return ret;
 138         default:
 139                 return -EINVAL;
 140         }
 141 }
 142
 143 static const struct iio_info tsl4531_info = {
 144         .read_raw = tsl4531_read_raw,
 145         .write_raw = tsl4531_write_raw,
 146         .attrs = &tsl4531_attribute_group,
 147         .driver_module = THIS_MODULE,
 148 };
 149
 150 static int tsl4531_check_id(struct i2c_client *client)
 151 {
 152         int ret = i2c_smbus_read_byte_data(client, TSL4531_ID);
 153         if (ret < 0)
 154                 return ret;
 155
 156         switch (ret >> TSL4531_ID_SHIFT) {
 157         case TSL45311_ID:
 158         case TSL45313_ID:
 159         case TSL45315_ID:
 160         case TSL45317_ID:
 161                 return 0;
 162         default:
 163                 return -ENODEV;
 164         }
 165 }
 166
 167 static int tsl4531_probe(struct i2c_client *client,
 168                           const struct i2c_device_id *id)
 169 {
 170         struct tsl4531_data *data;
 171         struct iio_dev *indio_dev;
 172         int ret;
 173
 174         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 175         if (!indio_dev)
 176                 return -ENOMEM;
 177
 178         data = iio_priv(indio_dev);
 179         i2c_set_clientdata(client, indio_dev);
 180         data->client = client;
 181         mutex_init(&data->lock);
 182
 183         ret = tsl4531_check_id(client);
 184         if (ret) {
 185                 dev_err(&client->dev, "no TSL4531 sensor\n");
 186                 return ret;
 187         }
 188
 189         ret = i2c_smbus_write_byte_data(data->client, TSL4531_CONTROL,
 190                 TSL4531_MODE_NORMAL);
 191         if (ret < 0)
 192                 return ret;
 193
 194         ret = i2c_smbus_write_byte_data(data->client, TSL4531_CONFIG,
 195                 TSL4531_TCNTRL_400MS);
 196         if (ret < 0)
 197                 return ret;
 198
 199         indio_dev->dev.parent = &client->dev;
 200         indio_dev->info = &tsl4531_info;
 201         indio_dev->channels = tsl4531_channels;
 202         indio_dev->num_channels = ARRAY_SIZE(tsl4531_channels);
 203         indio_dev->name = TSL4531_DRV_NAME;
 204         indio_dev->modes = INDIO_DIRECT_MODE;
 205
 206         return iio_device_register(indio_dev);
 207 }
 208
 209 static int tsl4531_powerdown(struct i2c_client *client)
 210 {
 211         return i2c_smbus_write_byte_data(client, TSL4531_CONTROL,
 212                 TSL4531_MODE_POWERDOWN);
 213 }
 214
 215 static int tsl4531_remove(struct i2c_client *client)
 216 {
 217         iio_device_unregister(i2c_get_clientdata(client));
 218         tsl4531_powerdown(client);
 219
 220         return 0;
 221 }
 222
 223 #ifdef CONFIG_PM_SLEEP
 224 static int tsl4531_suspend(struct device *dev)
 225 {
 226         return tsl4531_powerdown(to_i2c_client(dev));
 227 }
 228
 229 static int tsl4531_resume(struct device *dev)
 230 {
 231         return i2c_smbus_write_byte_data(to_i2c_client(dev), TSL4531_CONTROL,
 232                 TSL4531_MODE_NORMAL);
 233 }
 234
 235 static SIMPLE_DEV_PM_OPS(tsl4531_pm_ops, tsl4531_suspend, tsl4531_resume);
 236 #define TSL4531_PM_OPS (&tsl4531_pm_ops)
 237 #else
 238 #define TSL4531_PM_OPS NULL
 239 #endif
 240
 241 static const struct i2c_device_id tsl4531_id[] = {
 242         { "tsl4531", 0 },
 243         { }
 244 };
 245 MODULE_DEVICE_TABLE(i2c, tsl4531_id);
 246
 247 static struct i2c_driver tsl4531_driver = {
 248         .driver = {
 249                 .name   = TSL4531_DRV_NAME,
 250                 .pm     = TSL4531_PM_OPS,
 251         },
 252         .probe  = tsl4531_probe,
 253         .remove = tsl4531_remove,
 254         .id_table = tsl4531_id,
 255 };
 256
 257 module_i2c_driver(tsl4531_driver);
 258
 259 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
 260 MODULE_DESCRIPTION("TAOS TSL4531 ambient light sensors driver");
 261 MODULE_LICENSE("GPL");