drivers/misc/isl29003.c

   1 /*
   2  *  isl29003.c - Linux kernel module for
   3  *      Intersil ISL29003 ambient light sensor
   4  *
   5  *  See file:Documentation/misc-devices/isl29003
   6  *
   7  *  Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
   8  *
   9  *  Based on code written by
  10  *      Rodolfo Giometti <giometti@linux.it>
  11  *      Eurotech S.p.A. <info@eurotech.it>
  12  *
  13  *  This program is free software; you can redistribute it and/or modify
  14  *  it under the terms of the GNU General Public License as published by
  15  *  the Free Software Foundation; either version 2 of the License, or
  16  *  (at your option) any later version.
  17  *
  18  *  This program is distributed in the hope that it will be useful,
  19  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  *  GNU General Public License for more details.
  22  *
  23  *  You should have received a copy of the GNU General Public License
  24  *  along with this program; if not, write to the Free Software
  25  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  26  */
  27
  28 #include <linux/module.h>
  29 #include <linux/slab.h>
  30 #include <linux/i2c.h>
  31 #include <linux/mutex.h>
  32 #include <linux/delay.h>
  33
  34 #define ISL29003_DRV_NAME       "isl29003"
  35 #define DRIVER_VERSION          "1.0"
  36
  37 #define ISL29003_REG_COMMAND            0x00
  38 #define ISL29003_ADC_ENABLED            (1 << 7)
  39 #define ISL29003_ADC_PD                 (1 << 6)
  40 #define ISL29003_TIMING_INT             (1 << 5)
  41 #define ISL29003_MODE_SHIFT             (2)
  42 #define ISL29003_MODE_MASK              (0x3 << ISL29003_MODE_SHIFT)
  43 #define ISL29003_RES_SHIFT              (0)
  44 #define ISL29003_RES_MASK               (0x3 << ISL29003_RES_SHIFT)
  45
  46 #define ISL29003_REG_CONTROL            0x01
  47 #define ISL29003_INT_FLG                (1 << 5)
  48 #define ISL29003_RANGE_SHIFT            (2)
  49 #define ISL29003_RANGE_MASK             (0x3 << ISL29003_RANGE_SHIFT)
  50 #define ISL29003_INT_PERSISTS_SHIFT     (0)
  51 #define ISL29003_INT_PERSISTS_MASK      (0xf << ISL29003_INT_PERSISTS_SHIFT)
  52
  53 #define ISL29003_REG_IRQ_THRESH_HI      0x02
  54 #define ISL29003_REG_IRQ_THRESH_LO      0x03
  55 #define ISL29003_REG_LSB_SENSOR         0x04
  56 #define ISL29003_REG_MSB_SENSOR         0x05
  57 #define ISL29003_REG_LSB_TIMER          0x06
  58 #define ISL29003_REG_MSB_TIMER          0x07
  59
  60 #define ISL29003_NUM_CACHABLE_REGS      4
  61
  62 struct isl29003_data {
  63         struct i2c_client *client;
  64         struct mutex lock;
  65         u8 reg_cache[ISL29003_NUM_CACHABLE_REGS];
  66         u8 power_state_before_suspend;
  67 };
  68
  69 static int gain_range[] = {
  70         1000, 4000, 16000, 64000
  71 };
  72
  73 /*
  74  * register access helpers
  75  */
  76
  77 static int __isl29003_read_reg(struct i2c_client *client,
  78                                u32 reg, u8 mask, u8 shift)
  79 {
  80         struct isl29003_data *data = i2c_get_clientdata(client);
  81         return (data->reg_cache[reg] & mask) >> shift;
  82 }
  83
  84 static int __isl29003_write_reg(struct i2c_client *client,
  85                                 u32 reg, u8 mask, u8 shift, u8 val)
  86 {
  87         struct isl29003_data *data = i2c_get_clientdata(client);
  88         int ret = 0;
  89         u8 tmp;
  90
  91         if (reg >= ISL29003_NUM_CACHABLE_REGS)
  92                 return -EINVAL;
  93
  94         mutex_lock(&data->lock);
  95
  96         tmp = data->reg_cache[reg];
  97         tmp &= ~mask;
  98         tmp |= val << shift;
  99
 100         ret = i2c_smbus_write_byte_data(client, reg, tmp);
 101         if (!ret)
 102                 data->reg_cache[reg] = tmp;
 103
 104         mutex_unlock(&data->lock);
 105         return ret;
 106 }
 107
 108 /*
 109  * internally used functions
 110  */
 111
 112 /* range */
 113 static int isl29003_get_range(struct i2c_client *client)
 114 {
 115         return __isl29003_read_reg(client, ISL29003_REG_CONTROL,
 116                 ISL29003_RANGE_MASK, ISL29003_RANGE_SHIFT);
 117 }
 118
 119 static int isl29003_set_range(struct i2c_client *client, int range)
 120 {
 121         return __isl29003_write_reg(client, ISL29003_REG_CONTROL,
 122                 ISL29003_RANGE_MASK, ISL29003_RANGE_SHIFT, range);
 123 }
 124
 125 /* resolution */
 126 static int isl29003_get_resolution(struct i2c_client *client)
 127 {
 128         return __isl29003_read_reg(client, ISL29003_REG_COMMAND,
 129                 ISL29003_RES_MASK, ISL29003_RES_SHIFT);
 130 }
 131
 132 static int isl29003_set_resolution(struct i2c_client *client, int res)
 133 {
 134         return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
 135                 ISL29003_RES_MASK, ISL29003_RES_SHIFT, res);
 136 }
 137
 138 /* mode */
 139 static int isl29003_get_mode(struct i2c_client *client)
 140 {
 141         return __isl29003_read_reg(client, ISL29003_REG_COMMAND,
 142                 ISL29003_RES_MASK, ISL29003_RES_SHIFT);
 143 }
 144
 145 static int isl29003_set_mode(struct i2c_client *client, int mode)
 146 {
 147         return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
 148                 ISL29003_RES_MASK, ISL29003_RES_SHIFT, mode);
 149 }
 150
 151 /* power_state */
 152 static int isl29003_set_power_state(struct i2c_client *client, int state)
 153 {
 154         return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
 155                                 ISL29003_ADC_ENABLED | ISL29003_ADC_PD, 0,
 156                                 state ? ISL29003_ADC_ENABLED : ISL29003_ADC_PD);
 157 }
 158
 159 static int isl29003_get_power_state(struct i2c_client *client)
 160 {
 161         struct isl29003_data *data = i2c_get_clientdata(client);
 162         u8 cmdreg = data->reg_cache[ISL29003_REG_COMMAND];
 163         return ~cmdreg & ISL29003_ADC_PD;
 164 }
 165
 166 static int isl29003_get_adc_value(struct i2c_client *client)
 167 {
 168         struct isl29003_data *data = i2c_get_clientdata(client);
 169         int lsb, msb, range, bitdepth;
 170
 171         mutex_lock(&data->lock);
 172         lsb = i2c_smbus_read_byte_data(client, ISL29003_REG_LSB_SENSOR);
 173
 174         if (lsb < 0) {
 175                 mutex_unlock(&data->lock);
 176                 return lsb;
 177         }
 178
 179         msb = i2c_smbus_read_byte_data(client, ISL29003_REG_MSB_SENSOR);
 180         mutex_unlock(&data->lock);
 181
 182         if (msb < 0)
 183                 return msb;
 184
 185         range = isl29003_get_range(client);
 186         bitdepth = (4 - isl29003_get_resolution(client)) * 4;
 187         return (((msb << 8) | lsb) * gain_range[range]) >> bitdepth;
 188 }
 189
 190 /*
 191  * sysfs layer
 192  */
 193
 194 /* range */
 195 static ssize_t isl29003_show_range(struct device *dev,
 196                                    struct device_attribute *attr, char *buf)
 197 {
 198         struct i2c_client *client = to_i2c_client(dev);
 199         return sprintf(buf, "%i\n", isl29003_get_range(client));
 200 }
 201
 202 static ssize_t isl29003_store_range(struct device *dev,
 203                                     struct device_attribute *attr,
 204                                     const char *buf, size_t count)
 205 {
 206         struct i2c_client *client = to_i2c_client(dev);
 207         unsigned long val;
 208         int ret;
 209
 210         ret = kstrtoul(buf, 10, &val);
 211         if (ret)
 212                 return ret;
 213
 214         if (val > 3)
 215                 return -EINVAL;
 216
 217         ret = isl29003_set_range(client, val);
 218         if (ret < 0)
 219                 return ret;
 220
 221         return count;
 222 }
 223
 224 static DEVICE_ATTR(range, S_IWUSR | S_IRUGO,
 225                    isl29003_show_range, isl29003_store_range);
 226
 227
 228 /* resolution */
 229 static ssize_t isl29003_show_resolution(struct device *dev,
 230                                         struct device_attribute *attr,
 231                                         char *buf)
 232 {
 233         struct i2c_client *client = to_i2c_client(dev);
 234         return sprintf(buf, "%d\n", isl29003_get_resolution(client));
 235 }
 236
 237 static ssize_t isl29003_store_resolution(struct device *dev,
 238                                          struct device_attribute *attr,
 239                                          const char *buf, size_t count)
 240 {
 241         struct i2c_client *client = to_i2c_client(dev);
 242         unsigned long val;
 243         int ret;
 244
 245         ret = kstrtoul(buf, 10, &val);
 246         if (ret)
 247                 return ret;
 248
 249         if (val > 3)
 250                 return -EINVAL;
 251
 252         ret = isl29003_set_resolution(client, val);
 253         if (ret < 0)
 254                 return ret;
 255
 256         return count;
 257 }
 258
 259 static DEVICE_ATTR(resolution, S_IWUSR | S_IRUGO,
 260                    isl29003_show_resolution, isl29003_store_resolution);
 261
 262 /* mode */
 263 static ssize_t isl29003_show_mode(struct device *dev,
 264                                   struct device_attribute *attr, char *buf)
 265 {
 266         struct i2c_client *client = to_i2c_client(dev);
 267         return sprintf(buf, "%d\n", isl29003_get_mode(client));
 268 }
 269
 270 static ssize_t isl29003_store_mode(struct device *dev,
 271                 struct device_attribute *attr, const char *buf, size_t count)
 272 {
 273         struct i2c_client *client = to_i2c_client(dev);
 274         unsigned long val;
 275         int ret;
 276
 277         ret = kstrtoul(buf, 10, &val);
 278         if (ret)
 279                 return ret;
 280
 281         if (val > 2)
 282                 return -EINVAL;
 283
 284         ret = isl29003_set_mode(client, val);
 285         if (ret < 0)
 286                 return ret;
 287
 288         return count;
 289 }
 290
 291 static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO,
 292                    isl29003_show_mode, isl29003_store_mode);
 293
 294
 295 /* power state */
 296 static ssize_t isl29003_show_power_state(struct device *dev,
 297                                          struct device_attribute *attr,
 298                                          char *buf)
 299 {
 300         struct i2c_client *client = to_i2c_client(dev);
 301         return sprintf(buf, "%d\n", isl29003_get_power_state(client));
 302 }
 303
 304 static ssize_t isl29003_store_power_state(struct device *dev,
 305                                           struct device_attribute *attr,
 306                                           const char *buf, size_t count)
 307 {
 308         struct i2c_client *client = to_i2c_client(dev);
 309         unsigned long val;
 310         int ret;
 311
 312         ret = kstrtoul(buf, 10, &val);
 313         if (ret)
 314                 return ret;
 315
 316         if (val > 1)
 317                 return -EINVAL;
 318
 319         ret = isl29003_set_power_state(client, val);
 320         return ret ? ret : count;
 321 }
 322
 323 static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
 324                    isl29003_show_power_state, isl29003_store_power_state);
 325
 326
 327 /* lux */
 328 static ssize_t isl29003_show_lux(struct device *dev,
 329                                  struct device_attribute *attr, char *buf)
 330 {
 331         struct i2c_client *client = to_i2c_client(dev);
 332
 333         /* No LUX data if not operational */
 334         if (!isl29003_get_power_state(client))
 335                 return -EBUSY;
 336
 337         return sprintf(buf, "%d\n", isl29003_get_adc_value(client));
 338 }
 339
 340 static DEVICE_ATTR(lux, S_IRUGO, isl29003_show_lux, NULL);
 341
 342 static struct attribute *isl29003_attributes[] = {
 343         &dev_attr_range.attr,
 344         &dev_attr_resolution.attr,
 345         &dev_attr_mode.attr,
 346         &dev_attr_power_state.attr,
 347         &dev_attr_lux.attr,
 348         NULL
 349 };
 350
 351 static const struct attribute_group isl29003_attr_group = {
 352         .attrs = isl29003_attributes,
 353 };
 354
 355 static int isl29003_init_client(struct i2c_client *client)
 356 {
 357         struct isl29003_data *data = i2c_get_clientdata(client);
 358         int i;
 359
 360         /* read all the registers once to fill the cache.
 361          * if one of the reads fails, we consider the init failed */
 362         for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++) {
 363                 int v = i2c_smbus_read_byte_data(client, i);
 364                 if (v < 0)
 365                         return -ENODEV;
 366
 367                 data->reg_cache[i] = v;
 368         }
 369
 370         /* set defaults */
 371         isl29003_set_range(client, 0);
 372         isl29003_set_resolution(client, 0);
 373         isl29003_set_mode(client, 0);
 374         isl29003_set_power_state(client, 0);
 375
 376         return 0;
 377 }
 378
 379 /*
 380  * I2C layer
 381  */
 382
 383 static int isl29003_probe(struct i2c_client *client,
 384                                     const struct i2c_device_id *id)
 385 {
 386         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 387         struct isl29003_data *data;
 388         int err = 0;
 389
 390         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
 391                 return -EIO;
 392
 393         data = kzalloc(sizeof(struct isl29003_data), GFP_KERNEL);
 394         if (!data)
 395                 return -ENOMEM;
 396
 397         data->client = client;
 398         i2c_set_clientdata(client, data);
 399         mutex_init(&data->lock);
 400
 401         /* initialize the ISL29003 chip */
 402         err = isl29003_init_client(client);
 403         if (err)
 404                 goto exit_kfree;
 405
 406         /* register sysfs hooks */
 407         err = sysfs_create_group(&client->dev.kobj, &isl29003_attr_group);
 408         if (err)
 409                 goto exit_kfree;
 410
 411         dev_info(&client->dev, "driver version %s enabled\n", DRIVER_VERSION);
 412         return 0;
 413
 414 exit_kfree:
 415         kfree(data);
 416         return err;
 417 }
 418
 419 static int isl29003_remove(struct i2c_client *client)
 420 {
 421         sysfs_remove_group(&client->dev.kobj, &isl29003_attr_group);
 422         isl29003_set_power_state(client, 0);
 423         kfree(i2c_get_clientdata(client));
 424         return 0;
 425 }
 426
 427 #ifdef CONFIG_PM_SLEEP
 428 static int isl29003_suspend(struct device *dev)
 429 {
 430         struct i2c_client *client = to_i2c_client(dev);
 431         struct isl29003_data *data = i2c_get_clientdata(client);
 432
 433         data->power_state_before_suspend = isl29003_get_power_state(client);
 434         return isl29003_set_power_state(client, 0);
 435 }
 436
 437 static int isl29003_resume(struct device *dev)
 438 {
 439         int i;
 440         struct i2c_client *client = to_i2c_client(dev);
 441         struct isl29003_data *data = i2c_get_clientdata(client);
 442
 443         /* restore registers from cache */
 444         for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++)
 445                 if (i2c_smbus_write_byte_data(client, i, data->reg_cache[i]))
 446                         return -EIO;
 447
 448         return isl29003_set_power_state(client,
 449                 data->power_state_before_suspend);
 450 }
 451
 452 static SIMPLE_DEV_PM_OPS(isl29003_pm_ops, isl29003_suspend, isl29003_resume);
 453 #define ISL29003_PM_OPS (&isl29003_pm_ops)
 454
 455 #else
 456 #define ISL29003_PM_OPS NULL
 457 #endif /* CONFIG_PM_SLEEP */
 458
 459 static const struct i2c_device_id isl29003_id[] = {
 460         { "isl29003", 0 },
 461         {}
 462 };
 463 MODULE_DEVICE_TABLE(i2c, isl29003_id);
 464
 465 static struct i2c_driver isl29003_driver = {
 466         .driver = {
 467                 .name   = ISL29003_DRV_NAME,
 468                 .pm     = ISL29003_PM_OPS,
 469         },
 470         .probe  = isl29003_probe,
 471         .remove = isl29003_remove,
 472         .id_table = isl29003_id,
 473 };
 474
 475 module_i2c_driver(isl29003_driver);
 476
 477 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
 478 MODULE_DESCRIPTION("ISL29003 ambient light sensor driver");
 479 MODULE_LICENSE("GPL v2");
 480 MODULE_VERSION(DRIVER_VERSION);