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/init.h>
  30 #include <linux/slab.h>
  31 #include <linux/i2c.h>
  32 #include <linux/mutex.h>
  33 #include <linux/delay.h>
  34
  35 #define ISL29003_DRV_NAME       "isl29003"
  36 #define DRIVER_VERSION          "1.0"
  37
  38 #define ISL29003_REG_COMMAND            0x00
  39 #define ISL29003_ADC_ENABLED            (1 << 7)
  40 #define ISL29003_ADC_PD                 (1 << 6)
  41 #define ISL29003_TIMING_INT             (1 << 5)
  42 #define ISL29003_MODE_SHIFT             (2)
  43 #define ISL29003_MODE_MASK              (0x3 << ISL29003_MODE_SHIFT)
  44 #define ISL29003_RES_SHIFT              (0)
  45 #define ISL29003_RES_MASK               (0x3 << ISL29003_RES_SHIFT)
  46
  47 #define ISL29003_REG_CONTROL            0x01
  48 #define ISL29003_INT_FLG                (1 << 5)
  49 #define ISL29003_RANGE_SHIFT            (2)
  50 #define ISL29003_RANGE_MASK             (0x3 << ISL29003_RANGE_SHIFT)
  51 #define ISL29003_INT_PERSISTS_SHIFT     (0)
  52 #define ISL29003_INT_PERSISTS_MASK      (0xf << ISL29003_INT_PERSISTS_SHIFT)
  53
  54 #define ISL29003_REG_IRQ_THRESH_HI      0x02
  55 #define ISL29003_REG_IRQ_THRESH_LO      0x03
  56 #define ISL29003_REG_LSB_SENSOR         0x04
  57 #define ISL29003_REG_MSB_SENSOR         0x05
  58 #define ISL29003_REG_LSB_TIMER          0x06
  59 #define ISL29003_REG_MSB_TIMER          0x07
  60
  61 #define ISL29003_NUM_CACHABLE_REGS      4
  62
  63 struct isl29003_data {
  64         struct i2c_client *client;
  65         struct mutex lock;
  66         u8 reg_cache[ISL29003_NUM_CACHABLE_REGS];
  67         u8 power_state_before_suspend;
  68 };
  69
  70 static int gain_range[] = {
  71         1000, 4000, 16000, 64000
  72 };
  73
  74 /*
  75  * register access helpers
  76  */
  77
  78 static int __isl29003_read_reg(struct i2c_client *client,
  79                                u32 reg, u8 mask, u8 shift)
  80 {
  81         struct isl29003_data *data = i2c_get_clientdata(client);
  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         return ~cmdreg & ISL29003_ADC_PD;
 165 }
 166
 167 static int isl29003_get_adc_value(struct i2c_client *client)
 168 {
 169         struct isl29003_data *data = i2c_get_clientdata(client);
 170         int lsb, msb, range, bitdepth;
 171
 172         mutex_lock(&data->lock);
 173         lsb = i2c_smbus_read_byte_data(client, ISL29003_REG_LSB_SENSOR);
 174
 175         if (lsb < 0) {
 176                 mutex_unlock(&data->lock);
 177                 return lsb;
 178         }
 179
 180         msb = i2c_smbus_read_byte_data(client, ISL29003_REG_MSB_SENSOR);
 181         mutex_unlock(&data->lock);
 182
 183         if (msb < 0)
 184                 return msb;
 185
 186         range = isl29003_get_range(client);
 187         bitdepth = (4 - isl29003_get_resolution(client)) * 4;
 188         return (((msb << 8) | lsb) * gain_range[range]) >> bitdepth;
 189 }
 190
 191 /*
 192  * sysfs layer
 193  */
 194
 195 /* range */
 196 static ssize_t isl29003_show_range(struct device *dev,
 197                                    struct device_attribute *attr, char *buf)
 198 {
 199         struct i2c_client *client = to_i2c_client(dev);
 200         return sprintf(buf, "%i\n", isl29003_get_range(client));
 201 }
 202
 203 static ssize_t isl29003_store_range(struct device *dev,
 204                                     struct device_attribute *attr,
 205                                     const char *buf, size_t count)
 206 {
 207         struct i2c_client *client = to_i2c_client(dev);
 208         unsigned long val;
 209         int ret;
 210
 211         if ((strict_strtoul(buf, 10, &val) < 0) || (val > 3))
 212                 return -EINVAL;
 213
 214         ret = isl29003_set_range(client, val);
 215         if (ret < 0)
 216                 return ret;
 217
 218         return count;
 219 }
 220
 221 static DEVICE_ATTR(range, S_IWUSR | S_IRUGO,
 222                    isl29003_show_range, isl29003_store_range);
 223
 224
 225 /* resolution */
 226 static ssize_t isl29003_show_resolution(struct device *dev,
 227                                         struct device_attribute *attr,
 228                                         char *buf)
 229 {
 230         struct i2c_client *client = to_i2c_client(dev);
 231         return sprintf(buf, "%d\n", isl29003_get_resolution(client));
 232 }
 233
 234 static ssize_t isl29003_store_resolution(struct device *dev,
 235                                          struct device_attribute *attr,
 236                                          const char *buf, size_t count)
 237 {
 238         struct i2c_client *client = to_i2c_client(dev);
 239         unsigned long val;
 240         int ret;
 241
 242         if ((strict_strtoul(buf, 10, &val) < 0) || (val > 3))
 243                 return -EINVAL;
 244
 245         ret = isl29003_set_resolution(client, val);
 246         if (ret < 0)
 247                 return ret;
 248
 249         return count;
 250 }
 251
 252 static DEVICE_ATTR(resolution, S_IWUSR | S_IRUGO,
 253                    isl29003_show_resolution, isl29003_store_resolution);
 254
 255 /* mode */
 256 static ssize_t isl29003_show_mode(struct device *dev,
 257                                   struct device_attribute *attr, char *buf)
 258 {
 259         struct i2c_client *client = to_i2c_client(dev);
 260         return sprintf(buf, "%d\n", isl29003_get_mode(client));
 261 }
 262
 263 static ssize_t isl29003_store_mode(struct device *dev,
 264                 struct device_attribute *attr, const char *buf, size_t count)
 265 {
 266         struct i2c_client *client = to_i2c_client(dev);
 267         unsigned long val;
 268         int ret;
 269
 270         if ((strict_strtoul(buf, 10, &val) < 0) || (val > 2))
 271                 return -EINVAL;
 272
 273         ret = isl29003_set_mode(client, val);
 274         if (ret < 0)
 275                 return ret;
 276
 277         return count;
 278 }
 279
 280 static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO,
 281                    isl29003_show_mode, isl29003_store_mode);
 282
 283
 284 /* power state */
 285 static ssize_t isl29003_show_power_state(struct device *dev,
 286                                          struct device_attribute *attr,
 287                                          char *buf)
 288 {
 289         struct i2c_client *client = to_i2c_client(dev);
 290         return sprintf(buf, "%d\n", isl29003_get_power_state(client));
 291 }
 292
 293 static ssize_t isl29003_store_power_state(struct device *dev,
 294                                           struct device_attribute *attr,
 295                                           const char *buf, size_t count)
 296 {
 297         struct i2c_client *client = to_i2c_client(dev);
 298         unsigned long val;
 299         int ret;
 300
 301         if ((strict_strtoul(buf, 10, &val) < 0) || (val > 1))
 302                 return -EINVAL;
 303
 304         ret = isl29003_set_power_state(client, val);
 305         return ret ? ret : count;
 306 }
 307
 308 static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
 309                    isl29003_show_power_state, isl29003_store_power_state);
 310
 311
 312 /* lux */
 313 static ssize_t isl29003_show_lux(struct device *dev,
 314                                  struct device_attribute *attr, char *buf)
 315 {
 316         struct i2c_client *client = to_i2c_client(dev);
 317
 318         /* No LUX data if not operational */
 319         if (!isl29003_get_power_state(client))
 320                 return -EBUSY;
 321
 322         return sprintf(buf, "%d\n", isl29003_get_adc_value(client));
 323 }
 324
 325 static DEVICE_ATTR(lux, S_IRUGO, isl29003_show_lux, NULL);
 326
 327 static struct attribute *isl29003_attributes[] = {
 328         &dev_attr_range.attr,
 329         &dev_attr_resolution.attr,
 330         &dev_attr_mode.attr,
 331         &dev_attr_power_state.attr,
 332         &dev_attr_lux.attr,
 333         NULL
 334 };
 335
 336 static const struct attribute_group isl29003_attr_group = {
 337         .attrs = isl29003_attributes,
 338 };
 339
 340 static int isl29003_init_client(struct i2c_client *client)
 341 {
 342         struct isl29003_data *data = i2c_get_clientdata(client);
 343         int i;
 344
 345         /* read all the registers once to fill the cache.
 346          * if one of the reads fails, we consider the init failed */
 347         for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++) {
 348                 int v = i2c_smbus_read_byte_data(client, i);
 349                 if (v < 0)
 350                         return -ENODEV;
 351
 352                 data->reg_cache[i] = v;
 353         }
 354
 355         /* set defaults */
 356         isl29003_set_range(client, 0);
 357         isl29003_set_resolution(client, 0);
 358         isl29003_set_mode(client, 0);
 359         isl29003_set_power_state(client, 0);
 360
 361         return 0;
 362 }
 363
 364 /*
 365  * I2C layer
 366  */
 367
 368 static int __devinit isl29003_probe(struct i2c_client *client,
 369                                     const struct i2c_device_id *id)
 370 {
 371         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 372         struct isl29003_data *data;
 373         int err = 0;
 374
 375         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
 376                 return -EIO;
 377
 378         data = kzalloc(sizeof(struct isl29003_data), GFP_KERNEL);
 379         if (!data)
 380                 return -ENOMEM;
 381
 382         data->client = client;
 383         i2c_set_clientdata(client, data);
 384         mutex_init(&data->lock);
 385
 386         /* initialize the ISL29003 chip */
 387         err = isl29003_init_client(client);
 388         if (err)
 389                 goto exit_kfree;
 390
 391         /* register sysfs hooks */
 392         err = sysfs_create_group(&client->dev.kobj, &isl29003_attr_group);
 393         if (err)
 394                 goto exit_kfree;
 395
 396         dev_info(&client->dev, "driver version %s enabled\n", DRIVER_VERSION);
 397         return 0;
 398
 399 exit_kfree:
 400         kfree(data);
 401         return err;
 402 }
 403
 404 static int __devexit isl29003_remove(struct i2c_client *client)
 405 {
 406         sysfs_remove_group(&client->dev.kobj, &isl29003_attr_group);
 407         isl29003_set_power_state(client, 0);
 408         kfree(i2c_get_clientdata(client));
 409         return 0;
 410 }
 411
 412 #ifdef CONFIG_PM
 413 static int isl29003_suspend(struct i2c_client *client, pm_message_t mesg)
 414 {
 415         struct isl29003_data *data = i2c_get_clientdata(client);
 416
 417         data->power_state_before_suspend = isl29003_get_power_state(client);
 418         return isl29003_set_power_state(client, 0);
 419 }
 420
 421 static int isl29003_resume(struct i2c_client *client)
 422 {
 423         int i;
 424         struct isl29003_data *data = i2c_get_clientdata(client);
 425
 426         /* restore registers from cache */
 427         for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++)
 428                 if (i2c_smbus_write_byte_data(client, i, data->reg_cache[i]))
 429                         return -EIO;
 430
 431         return isl29003_set_power_state(client,
 432                 data->power_state_before_suspend);
 433 }
 434
 435 #else
 436 #define isl29003_suspend        NULL
 437 #define isl29003_resume         NULL
 438 #endif /* CONFIG_PM */
 439
 440 static const struct i2c_device_id isl29003_id[] = {
 441         { "isl29003", 0 },
 442         {}
 443 };
 444 MODULE_DEVICE_TABLE(i2c, isl29003_id);
 445
 446 static struct i2c_driver isl29003_driver = {
 447         .driver = {
 448                 .name   = ISL29003_DRV_NAME,
 449                 .owner  = THIS_MODULE,
 450         },
 451         .suspend = isl29003_suspend,
 452         .resume = isl29003_resume,
 453         .probe  = isl29003_probe,
 454         .remove = __devexit_p(isl29003_remove),
 455         .id_table = isl29003_id,
 456 };
 457
 458 module_i2c_driver(isl29003_driver);
 459
 460 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
 461 MODULE_DESCRIPTION("ISL29003 ambient light sensor driver");
 462 MODULE_LICENSE("GPL v2");
 463 MODULE_VERSION(DRIVER_VERSION);