drivers/iio/light/adjd_s311.c

   1 /*
   2  * adjd_s311.c - Support for ADJD-S311-CR999 digital color sensor
   3  *
   4  * Copyright (C) 2012 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  * driver for ADJD-S311-CR999 digital color sensor (10-bit channels for
  11  * red, green, blue, clear); 7-bit I2C slave address 0x74
  12  *
  13  * limitations: no calibration, no offset mode, no sleep mode
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/i2c.h>
  20 #include <linux/slab.h>
  21 #include <linux/delay.h>
  22 #include <linux/bitmap.h>
  23 #include <linux/err.h>
  24 #include <linux/irq.h>
  25
  26 #include <linux/iio/iio.h>
  27 #include <linux/iio/sysfs.h>
  28 #include <linux/iio/trigger_consumer.h>
  29 #include <linux/iio/buffer.h>
  30 #include <linux/iio/triggered_buffer.h>
  31
  32 #define ADJD_S311_DRV_NAME "adjd_s311"
  33
  34 #define ADJD_S311_CTRL          0x00
  35 #define ADJD_S311_CONFIG        0x01
  36 #define ADJD_S311_CAP_RED       0x06
  37 #define ADJD_S311_CAP_GREEN     0x07
  38 #define ADJD_S311_CAP_BLUE      0x08
  39 #define ADJD_S311_CAP_CLEAR     0x09
  40 #define ADJD_S311_INT_RED       0x0a
  41 #define ADJD_S311_INT_GREEN     0x0c
  42 #define ADJD_S311_INT_BLUE      0x0e
  43 #define ADJD_S311_INT_CLEAR     0x10
  44 #define ADJD_S311_DATA_RED      0x40
  45 #define ADJD_S311_DATA_GREEN    0x42
  46 #define ADJD_S311_DATA_BLUE     0x44
  47 #define ADJD_S311_DATA_CLEAR    0x46
  48 #define ADJD_S311_OFFSET_RED    0x48
  49 #define ADJD_S311_OFFSET_GREEN  0x49
  50 #define ADJD_S311_OFFSET_BLUE   0x4a
  51 #define ADJD_S311_OFFSET_CLEAR  0x4b
  52
  53 #define ADJD_S311_CTRL_GOFS     0x02
  54 #define ADJD_S311_CTRL_GSSR     0x01
  55 #define ADJD_S311_CAP_MASK      0x0f
  56 #define ADJD_S311_INT_MASK      0x0fff
  57 #define ADJD_S311_DATA_MASK     0x03ff
  58
  59 struct adjd_s311_data {
  60         struct i2c_client *client;
  61         u16 *buffer;
  62 };
  63
  64 enum adjd_s311_channel_idx {
  65         IDX_RED, IDX_GREEN, IDX_BLUE, IDX_CLEAR
  66 };
  67
  68 #define ADJD_S311_DATA_REG(chan) (ADJD_S311_DATA_RED + (chan) * 2)
  69 #define ADJD_S311_INT_REG(chan) (ADJD_S311_INT_RED + (chan) * 2)
  70 #define ADJD_S311_CAP_REG(chan) (ADJD_S311_CAP_RED + (chan))
  71
  72 static int adjd_s311_req_data(struct iio_dev *indio_dev)
  73 {
  74         struct adjd_s311_data *data = iio_priv(indio_dev);
  75         int tries = 10;
  76
  77         int ret = i2c_smbus_write_byte_data(data->client, ADJD_S311_CTRL,
  78                 ADJD_S311_CTRL_GSSR);
  79         if (ret < 0)
  80                 return ret;
  81
  82         while (tries--) {
  83                 ret = i2c_smbus_read_byte_data(data->client, ADJD_S311_CTRL);
  84                 if (ret < 0)
  85                         return ret;
  86                 if (!(ret & ADJD_S311_CTRL_GSSR))
  87                         break;
  88                 msleep(20);
  89         }
  90
  91         if (tries < 0) {
  92                 dev_err(&data->client->dev,
  93                         "adjd_s311_req_data() failed, data not ready\n");
  94                 return -EIO;
  95         }
  96
  97         return 0;
  98 }
  99
 100 static int adjd_s311_read_data(struct iio_dev *indio_dev, u8 reg, int *val)
 101 {
 102         struct adjd_s311_data *data = iio_priv(indio_dev);
 103
 104         int ret = adjd_s311_req_data(indio_dev);
 105         if (ret < 0)
 106                 return ret;
 107
 108         ret = i2c_smbus_read_word_data(data->client, reg);
 109         if (ret < 0)
 110                 return ret;
 111
 112         *val = ret & ADJD_S311_DATA_MASK;
 113
 114         return 0;
 115 }
 116
 117 static irqreturn_t adjd_s311_trigger_handler(int irq, void *p)
 118 {
 119         struct iio_poll_func *pf = p;
 120         struct iio_dev *indio_dev = pf->indio_dev;
 121         struct adjd_s311_data *data = iio_priv(indio_dev);
 122         s64 time_ns = iio_get_time_ns();
 123         int len = 0;
 124         int i, j = 0;
 125
 126         int ret = adjd_s311_req_data(indio_dev);
 127         if (ret < 0)
 128                 goto done;
 129
 130         for_each_set_bit(i, indio_dev->active_scan_mask,
 131                 indio_dev->masklength) {
 132                 ret = i2c_smbus_read_word_data(data->client,
 133                         ADJD_S311_DATA_REG(i));
 134                 if (ret < 0)
 135                         goto done;
 136
 137                 data->buffer[j++] = ret & ADJD_S311_DATA_MASK;
 138                 len += 2;
 139         }
 140
 141         iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, time_ns);
 142
 143 done:
 144         iio_trigger_notify_done(indio_dev->trig);
 145
 146         return IRQ_HANDLED;
 147 }
 148
 149 #define ADJD_S311_CHANNEL(_color, _scan_idx) { \
 150         .type = IIO_INTENSITY, \
 151         .modified = 1, \
 152         .address = (IDX_##_color), \
 153         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
 154                 BIT(IIO_CHAN_INFO_HARDWAREGAIN) | \
 155                 BIT(IIO_CHAN_INFO_INT_TIME), \
 156         .channel2 = (IIO_MOD_LIGHT_##_color), \
 157         .scan_index = (_scan_idx), \
 158         .scan_type = { \
 159                 .sign = 'u', \
 160                 .realbits = 10, \
 161                 .storagebits = 16, \
 162                 .endianness = IIO_CPU, \
 163         }, \
 164 }
 165
 166 static const struct iio_chan_spec adjd_s311_channels[] = {
 167         ADJD_S311_CHANNEL(RED, 0),
 168         ADJD_S311_CHANNEL(GREEN, 1),
 169         ADJD_S311_CHANNEL(BLUE, 2),
 170         ADJD_S311_CHANNEL(CLEAR, 3),
 171         IIO_CHAN_SOFT_TIMESTAMP(4),
 172 };
 173
 174 static int adjd_s311_read_raw(struct iio_dev *indio_dev,
 175                            struct iio_chan_spec const *chan,
 176                            int *val, int *val2, long mask)
 177 {
 178         struct adjd_s311_data *data = iio_priv(indio_dev);
 179         int ret;
 180
 181         switch (mask) {
 182         case IIO_CHAN_INFO_RAW:
 183                 ret = adjd_s311_read_data(indio_dev,
 184                         ADJD_S311_DATA_REG(chan->address), val);
 185                 if (ret < 0)
 186                         return ret;
 187                 return IIO_VAL_INT;
 188         case IIO_CHAN_INFO_HARDWAREGAIN:
 189                 ret = i2c_smbus_read_byte_data(data->client,
 190                         ADJD_S311_CAP_REG(chan->address));
 191                 if (ret < 0)
 192                         return ret;
 193                 *val = ret & ADJD_S311_CAP_MASK;
 194                 return IIO_VAL_INT;
 195         case IIO_CHAN_INFO_INT_TIME:
 196                 ret = i2c_smbus_read_word_data(data->client,
 197                         ADJD_S311_INT_REG(chan->address));
 198                 if (ret < 0)
 199                         return ret;
 200                 *val = 0;
 201                 /*
 202                  * not documented, based on measurement:
 203                  * 4095 LSBs correspond to roughly 4 ms
 204                  */
 205                 *val2 = ret & ADJD_S311_INT_MASK;
 206                 return IIO_VAL_INT_PLUS_MICRO;
 207         }
 208         return -EINVAL;
 209 }
 210
 211 static int adjd_s311_write_raw(struct iio_dev *indio_dev,
 212                                struct iio_chan_spec const *chan,
 213                                int val, int val2, long mask)
 214 {
 215         struct adjd_s311_data *data = iio_priv(indio_dev);
 216
 217         switch (mask) {
 218         case IIO_CHAN_INFO_HARDWAREGAIN:
 219                 if (val < 0 || val > ADJD_S311_CAP_MASK)
 220                         return -EINVAL;
 221
 222                 return i2c_smbus_write_byte_data(data->client,
 223                         ADJD_S311_CAP_REG(chan->address), val);
 224         case IIO_CHAN_INFO_INT_TIME:
 225                 if (val != 0 || val2 < 0 || val2 > ADJD_S311_INT_MASK)
 226                         return -EINVAL;
 227
 228                 return i2c_smbus_write_word_data(data->client,
 229                         ADJD_S311_INT_REG(chan->address), val2);
 230         }
 231         return -EINVAL;
 232 }
 233
 234 static int adjd_s311_update_scan_mode(struct iio_dev *indio_dev,
 235         const unsigned long *scan_mask)
 236 {
 237         struct adjd_s311_data *data = iio_priv(indio_dev);
 238
 239         kfree(data->buffer);
 240         data->buffer = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
 241         if (data->buffer == NULL)
 242                 return -ENOMEM;
 243
 244         return 0;
 245 }
 246
 247 static const struct iio_info adjd_s311_info = {
 248         .read_raw = adjd_s311_read_raw,
 249         .write_raw = adjd_s311_write_raw,
 250         .update_scan_mode = adjd_s311_update_scan_mode,
 251         .driver_module = THIS_MODULE,
 252 };
 253
 254 static int adjd_s311_probe(struct i2c_client *client,
 255                            const struct i2c_device_id *id)
 256 {
 257         struct adjd_s311_data *data;
 258         struct iio_dev *indio_dev;
 259         int err;
 260
 261         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 262         if (indio_dev == NULL)
 263                 return -ENOMEM;
 264
 265         data = iio_priv(indio_dev);
 266         i2c_set_clientdata(client, indio_dev);
 267         data->client = client;
 268
 269         indio_dev->dev.parent = &client->dev;
 270         indio_dev->info = &adjd_s311_info;
 271         indio_dev->name = ADJD_S311_DRV_NAME;
 272         indio_dev->channels = adjd_s311_channels;
 273         indio_dev->num_channels = ARRAY_SIZE(adjd_s311_channels);
 274         indio_dev->modes = INDIO_DIRECT_MODE;
 275
 276         err = iio_triggered_buffer_setup(indio_dev, NULL,
 277                 adjd_s311_trigger_handler, NULL);
 278         if (err < 0)
 279                 return err;
 280
 281         err = iio_device_register(indio_dev);
 282         if (err)
 283                 goto exit_unreg_buffer;
 284
 285         dev_info(&client->dev, "ADJD-S311 color sensor registered\n");
 286
 287         return 0;
 288
 289 exit_unreg_buffer:
 290         iio_triggered_buffer_cleanup(indio_dev);
 291         return err;
 292 }
 293
 294 static int adjd_s311_remove(struct i2c_client *client)
 295 {
 296         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 297         struct adjd_s311_data *data = iio_priv(indio_dev);
 298
 299         iio_device_unregister(indio_dev);
 300         iio_triggered_buffer_cleanup(indio_dev);
 301         kfree(data->buffer);
 302
 303         return 0;
 304 }
 305
 306 static const struct i2c_device_id adjd_s311_id[] = {
 307         { "adjd_s311", 0 },
 308         { }
 309 };
 310 MODULE_DEVICE_TABLE(i2c, adjd_s311_id);
 311
 312 static struct i2c_driver adjd_s311_driver = {
 313         .driver = {
 314                 .name   = ADJD_S311_DRV_NAME,
 315         },
 316         .probe          = adjd_s311_probe,
 317         .remove         = adjd_s311_remove,
 318         .id_table       = adjd_s311_id,
 319 };
 320 module_i2c_driver(adjd_s311_driver);
 321
 322 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
 323 MODULE_DESCRIPTION("ADJD-S311 color sensor");
 324 MODULE_LICENSE("GPL");