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
  82         return (data->reg_cache[reg] & mask) >> shift;
  83 }
  84
  85 static int __isl29003_write_reg(struct i2c_client *client,
  86                                 u32 reg, u8 mask, u8 shift, u8 val)
  87 {
  88         struct isl29003_data *data = i2c_get_clientdata(client);
  89         int ret = 0;
  90         u8 tmp;
  91
  92         if (reg >= ISL29003_NUM_CACHABLE_REGS)
  93                 return -EINVAL;
  94
  95         mutex_lock(&data->lock);
  96
  97         tmp = data->reg_cache[reg];
  98         tmp &= ~mask;
  99         tmp |= val << shift;
 100
 101         ret = i2c_smbus_write_byte_data(client, reg, tmp);
 102         if (!ret)
 103                 data->reg_cache[reg] = tmp;
 104
 105         mutex_unlock(&data->lock);
 106         return ret;
 107 }
 108
 109 /*
 110  * internally used functions
 111  */
 112
 113 /* range */
 114 static int isl29003_get_range(struct i2c_client *client)
 115 {
 116         return __isl29003_read_reg(client, ISL29003_REG_CONTROL,
 117                 ISL29003_RANGE_MASK, ISL29003_RANGE_SHIFT);
 118 }
 119
 120 static int isl29003_set_range(struct i2c_client *client, int range)
 121 {
 122         return __isl29003_write_reg(client, ISL29003_REG_CONTROL,
 123                 ISL29003_RANGE_MASK, ISL29003_RANGE_SHIFT, range);
 124 }
 125
 126 /* resolution */
 127 static int isl29003_get_resolution(struct i2c_client *client)
 128 {
 129         return __isl29003_read_reg(client, ISL29003_REG_COMMAND,
 130                 ISL29003_RES_MASK, ISL29003_RES_SHIFT);
 131 }
 132
 133 static int isl29003_set_resolution(struct i2c_client *client, int res)
 134 {
 135         return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
 136                 ISL29003_RES_MASK, ISL29003_RES_SHIFT, res);
 137 }
 138
 139 /* mode */
 140 static int isl29003_get_mode(struct i2c_client *client)
 141 {
 142         return __isl29003_read_reg(client, ISL29003_REG_COMMAND,
 143                 ISL29003_RES_MASK, ISL29003_RES_SHIFT);
 144 }
 145
 146 static int isl29003_set_mode(struct i2c_client *client, int mode)
 147 {
 148         return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
 149                 ISL29003_RES_MASK, ISL29003_RES_SHIFT, mode);
 150 }
 151
 152 /* power_state */
 153 static int isl29003_set_power_state(struct i2c_client *client, int state)
 154 {
 155         return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
 156                                 ISL29003_ADC_ENABLED | ISL29003_ADC_PD, 0,
 157                                 state ? ISL29003_ADC_ENABLED : ISL29003_ADC_PD);
 158 }
 159
 160 static int isl29003_get_power_state(struct i2c_client *client)
 161 {
 162         struct isl29003_data *data = i2c_get_clientdata(client);
 163         u8 cmdreg = data->reg_cache[ISL29003_REG_COMMAND];
 164
 165         return ~cmdreg & ISL29003_ADC_PD;
 166 }
 167
 168 static int isl29003_get_adc_value(struct i2c_client *client)
 169 {
 170         struct isl29003_data *data = i2c_get_clientdata(client);
 171         int lsb, msb, range, bitdepth;
 172
 173         mutex_lock(&data->lock);
 174         lsb = i2c_smbus_read_byte_data(client, ISL29003_REG_LSB_SENSOR);
 175
 176         if (lsb < 0) {
 177                 mutex_unlock(&data->lock);
 178                 return lsb;
 179         }
 180
 181         msb = i2c_smbus_read_byte_data(client, ISL29003_REG_MSB_SENSOR);
 182         mutex_unlock(&data->lock);
 183
 184         if (msb < 0)
 185                 return msb;
 186
 187         range = isl29003_get_range(client);
 188         bitdepth = (4 - isl29003_get_resolution(client)) * 4;
 189         return (((msb << 8) | lsb) * gain_range[range]) >> bitdepth;
 190 }
 191
 192 /*
 193  * sysfs layer
 194  */
 195
 196 /* range */
 197 static ssize_t isl29003_show_range(struct device *dev,
 198                                    struct device_attribute *attr, char *buf)
 199 {
 200         struct i2c_client *client = to_i2c_client(dev);
 201
 202         return sprintf(buf, "%i\n", isl29003_get_range(client));
 203 }
 204
 205 static ssize_t isl29003_store_range(struct device *dev,
 206                                     struct device_attribute *attr,
 207                                     const char *buf, size_t count)
 208 {
 209         struct i2c_client *client = to_i2c_client(dev);
 210         unsigned long val;
 211         int ret;
 212
 213         ret = kstrtoul(buf, 10, &val);
 214         if (ret)
 215                 return ret;
 216
 217         if (val > 3)
 218                 return -EINVAL;
 219
 220         ret = isl29003_set_range(client, val);
 221         if (ret < 0)
 222                 return ret;
 223
 224         return count;
 225 }
 226
 227 static DEVICE_ATTR(range, S_IWUSR | S_IRUGO,
 228                    isl29003_show_range, isl29003_store_range);
 229
 230
 231 /* resolution */
 232 static ssize_t isl29003_show_resolution(struct device *dev,
 233                                         struct device_attribute *attr,
 234                                         char *buf)
 235 {
 236         struct i2c_client *client = to_i2c_client(dev);
 237
 238         return sprintf(buf, "%d\n", isl29003_get_resolution(client));
 239 }
 240
 241 static ssize_t isl29003_store_resolution(struct device *dev,
 242                                          struct device_attribute *attr,
 243                                          const char *buf, size_t count)
 244 {
 245         struct i2c_client *client = to_i2c_client(dev);
 246         unsigned long val;
 247         int ret;
 248
 249         ret = kstrtoul(buf, 10, &val);
 250         if (ret)
 251                 return ret;
 252
 253         if (val > 3)
 254                 return -EINVAL;
 255
 256         ret = isl29003_set_resolution(client, val);
 257         if (ret < 0)
 258                 return ret;
 259
 260         return count;
 261 }
 262
 263 static DEVICE_ATTR(resolution, S_IWUSR | S_IRUGO,
 264                    isl29003_show_resolution, isl29003_store_resolution);
 265
 266 /* mode */
 267 static ssize_t isl29003_show_mode(struct device *dev,
 268                                   struct device_attribute *attr, char *buf)
 269 {
 270         struct i2c_client *client = to_i2c_client(dev);
 271
 272         return sprintf(buf, "%d\n", isl29003_get_mode(client));
 273 }
 274
 275 static ssize_t isl29003_store_mode(struct device *dev,
 276                 struct device_attribute *attr, const char *buf, size_t count)
 277 {
 278         struct i2c_client *client = to_i2c_client(dev);
 279         unsigned long val;
 280         int ret;
 281
 282         ret = kstrtoul(buf, 10, &val);
 283         if (ret)
 284                 return ret;
 285
 286         if (val > 2)
 287                 return -EINVAL;
 288
 289         ret = isl29003_set_mode(client, val);
 290         if (ret < 0)
 291                 return ret;
 292
 293         return count;
 294 }
 295
 296 static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO,
 297                    isl29003_show_mode, isl29003_store_mode);
 298
 299
 300 /* power state */
 301 static ssize_t isl29003_show_power_state(struct device *dev,
 302                                          struct device_attribute *attr,
 303                                          char *buf)
 304 {
 305         struct i2c_client *client = to_i2c_client(dev);
 306
 307         return sprintf(buf, "%d\n", isl29003_get_power_state(client));
 308 }
 309
 310 static ssize_t isl29003_store_power_state(struct device *dev,
 311                                           struct device_attribute *attr,
 312                                           const char *buf, size_t count)
 313 {
 314         struct i2c_client *client = to_i2c_client(dev);
 315         unsigned long val;
 316         int ret;
 317
 318         ret = kstrtoul(buf, 10, &val);
 319         if (ret)
 320                 return ret;
 321
 322         if (val > 1)
 323                 return -EINVAL;
 324
 325         ret = isl29003_set_power_state(client, val);
 326         return ret ? ret : count;
 327 }
 328
 329 static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
 330                    isl29003_show_power_state, isl29003_store_power_state);
 331
 332
 333 /* lux */
 334 static ssize_t isl29003_show_lux(struct device *dev,
 335                                  struct device_attribute *attr, char *buf)
 336 {
 337         struct i2c_client *client = to_i2c_client(dev);
 338
 339         /* No LUX data if not operational */
 340         if (!isl29003_get_power_state(client))
 341                 return -EBUSY;
 342
 343         return sprintf(buf, "%d\n", isl29003_get_adc_value(client));
 344 }
 345
 346 static DEVICE_ATTR(lux, S_IRUGO, isl29003_show_lux, NULL);
 347
 348 static struct attribute *isl29003_attributes[] = {
 349         &dev_attr_range.attr,
 350         &dev_attr_resolution.attr,
 351         &dev_attr_mode.attr,
 352         &dev_attr_power_state.attr,
 353         &dev_attr_lux.attr,
 354         NULL
 355 };
 356
 357 static const struct attribute_group isl29003_attr_group = {
 358         .attrs = isl29003_attributes,
 359 };
 360
 361 static int isl29003_init_client(struct i2c_client *client)
 362 {
 363         struct isl29003_data *data = i2c_get_clientdata(client);
 364         int i;
 365
 366         /* read all the registers once to fill the cache.
 367          * if one of the reads fails, we consider the init failed */
 368         for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++) {
 369                 int v = i2c_smbus_read_byte_data(client, i);
 370
 371                 if (v < 0)
 372                         return -ENODEV;
 373
 374                 data->reg_cache[i] = v;
 375         }
 376
 377         /* set defaults */
 378         isl29003_set_range(client, 0);
 379         isl29003_set_resolution(client, 0);
 380         isl29003_set_mode(client, 0);
 381         isl29003_set_power_state(client, 0);
 382
 383         return 0;
 384 }
 385
 386 /*
 387  * I2C layer
 388  */
 389
 390 static int isl29003_probe(struct i2c_client *client,
 391                                     const struct i2c_device_id *id)
 392 {
 393         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 394         struct isl29003_data *data;
 395         int err = 0;
 396
 397         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
 398                 return -EIO;
 399
 400         data = kzalloc(sizeof(struct isl29003_data), GFP_KERNEL);
 401         if (!data)
 402                 return -ENOMEM;
 403
 404         data->client = client;
 405         i2c_set_clientdata(client, data);
 406         mutex_init(&data->lock);
 407
 408         /* initialize the ISL29003 chip */
 409         err = isl29003_init_client(client);
 410         if (err)
 411                 goto exit_kfree;
 412
 413         /* register sysfs hooks */
 414         err = sysfs_create_group(&client->dev.kobj, &isl29003_attr_group);
 415         if (err)
 416                 goto exit_kfree;
 417
 418         dev_info(&client->dev, "driver version %s enabled\n", DRIVER_VERSION);
 419         return 0;
 420
 421 exit_kfree:
 422         kfree(data);
 423         return err;
 424 }
 425
 426 static int isl29003_remove(struct i2c_client *client)
 427 {
 428         sysfs_remove_group(&client->dev.kobj, &isl29003_attr_group);
 429         isl29003_set_power_state(client, 0);
 430         kfree(i2c_get_clientdata(client));
 431         return 0;
 432 }
 433
 434 #ifdef CONFIG_PM_SLEEP
 435 static int isl29003_suspend(struct device *dev)
 436 {
 437         struct i2c_client *client = to_i2c_client(dev);
 438         struct isl29003_data *data = i2c_get_clientdata(client);
 439
 440         data->power_state_before_suspend = isl29003_get_power_state(client);
 441         return isl29003_set_power_state(client, 0);
 442 }
 443
 444 static int isl29003_resume(struct device *dev)
 445 {
 446         int i;
 447         struct i2c_client *client = to_i2c_client(dev);
 448         struct isl29003_data *data = i2c_get_clientdata(client);
 449
 450         /* restore registers from cache */
 451         for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++)
 452                 if (i2c_smbus_write_byte_data(client, i, data->reg_cache[i]))
 453                         return -EIO;
 454
 455         return isl29003_set_power_state(client,
 456                 data->power_state_before_suspend);
 457 }
 458
 459 static SIMPLE_DEV_PM_OPS(isl29003_pm_ops, isl29003_suspend, isl29003_resume);
 460 #define ISL29003_PM_OPS (&isl29003_pm_ops)
 461
 462 #else
 463 #define ISL29003_PM_OPS NULL
 464 #endif /* CONFIG_PM_SLEEP */
 465
 466 static const struct i2c_device_id isl29003_id[] = {
 467         { "isl29003", 0 },
 468         {}
 469 };
 470 MODULE_DEVICE_TABLE(i2c, isl29003_id);
 471
 472 static struct i2c_driver isl29003_driver = {
 473         .driver = {
 474                 .name   = ISL29003_DRV_NAME,
 475                 .pm     = ISL29003_PM_OPS,
 476         },
 477         .probe  = isl29003_probe,
 478         .remove = isl29003_remove,
 479         .id_table = isl29003_id,
 480 };
 481
 482 module_i2c_driver(isl29003_driver);
 483
 484 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
 485 MODULE_DESCRIPTION("ISL29003 ambient light sensor driver");
 486 MODULE_LICENSE("GPL v2");
 487 MODULE_VERSION(DRIVER_VERSION);