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