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 }; 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 if ((strict_strtoul(buf, 10, &val) < 0) || (val > 3)) 211 return -EINVAL; 212 213 ret = isl29003_set_range(client, val); 214 if (ret < 0) 215 return ret; 216 217 return count; 218 } 219 220 static DEVICE_ATTR(range, S_IWUSR | S_IRUGO, 221 isl29003_show_range, isl29003_store_range); 222 223 224 /* resolution */ 225 static ssize_t isl29003_show_resolution(struct device *dev, 226 struct device_attribute *attr, 227 char *buf) 228 { 229 struct i2c_client *client = to_i2c_client(dev); 230 return sprintf(buf, "%d\n", isl29003_get_resolution(client)); 231 } 232 233 static ssize_t isl29003_store_resolution(struct device *dev, 234 struct device_attribute *attr, 235 const char *buf, size_t count) 236 { 237 struct i2c_client *client = to_i2c_client(dev); 238 unsigned long val; 239 int ret; 240 241 if ((strict_strtoul(buf, 10, &val) < 0) || (val > 3)) 242 return -EINVAL; 243 244 ret = isl29003_set_resolution(client, val); 245 if (ret < 0) 246 return ret; 247 248 return count; 249 } 250 251 static DEVICE_ATTR(resolution, S_IWUSR | S_IRUGO, 252 isl29003_show_resolution, isl29003_store_resolution); 253 254 /* mode */ 255 static ssize_t isl29003_show_mode(struct device *dev, 256 struct device_attribute *attr, char *buf) 257 { 258 struct i2c_client *client = to_i2c_client(dev); 259 return sprintf(buf, "%d\n", isl29003_get_mode(client)); 260 } 261 262 static ssize_t isl29003_store_mode(struct device *dev, 263 struct device_attribute *attr, const char *buf, size_t count) 264 { 265 struct i2c_client *client = to_i2c_client(dev); 266 unsigned long val; 267 int ret; 268 269 if ((strict_strtoul(buf, 10, &val) < 0) || (val > 2)) 270 return -EINVAL; 271 272 ret = isl29003_set_mode(client, val); 273 if (ret < 0) 274 return ret; 275 276 return count; 277 } 278 279 static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO, 280 isl29003_show_mode, isl29003_store_mode); 281 282 283 /* power state */ 284 static ssize_t isl29003_show_power_state(struct device *dev, 285 struct device_attribute *attr, 286 char *buf) 287 { 288 struct i2c_client *client = to_i2c_client(dev); 289 return sprintf(buf, "%d\n", isl29003_get_power_state(client)); 290 } 291 292 static ssize_t isl29003_store_power_state(struct device *dev, 293 struct device_attribute *attr, 294 const char *buf, size_t count) 295 { 296 struct i2c_client *client = to_i2c_client(dev); 297 unsigned long val; 298 int ret; 299 300 if ((strict_strtoul(buf, 10, &val) < 0) || (val > 1)) 301 return -EINVAL; 302 303 ret = isl29003_set_power_state(client, val); 304 return ret ? ret : count; 305 } 306 307 static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO, 308 isl29003_show_power_state, isl29003_store_power_state); 309 310 311 /* lux */ 312 static ssize_t isl29003_show_lux(struct device *dev, 313 struct device_attribute *attr, char *buf) 314 { 315 struct i2c_client *client = to_i2c_client(dev); 316 317 /* No LUX data if not operational */ 318 if (!isl29003_get_power_state(client)) 319 return -EBUSY; 320 321 return sprintf(buf, "%d\n", isl29003_get_adc_value(client)); 322 } 323 324 static DEVICE_ATTR(lux, S_IRUGO, isl29003_show_lux, NULL); 325 326 static struct attribute *isl29003_attributes[] = { 327 &dev_attr_range.attr, 328 &dev_attr_resolution.attr, 329 &dev_attr_mode.attr, 330 &dev_attr_power_state.attr, 331 &dev_attr_lux.attr, 332 NULL 333 }; 334 335 static const struct attribute_group isl29003_attr_group = { 336 .attrs = isl29003_attributes, 337 }; 338 339 static int isl29003_init_client(struct i2c_client *client) 340 { 341 struct isl29003_data *data = i2c_get_clientdata(client); 342 int i; 343 344 /* read all the registers once to fill the cache. 345 * if one of the reads fails, we consider the init failed */ 346 for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++) { 347 int v = i2c_smbus_read_byte_data(client, i); 348 if (v < 0) 349 return -ENODEV; 350 351 data->reg_cache[i] = v; 352 } 353 354 /* set defaults */ 355 isl29003_set_range(client, 0); 356 isl29003_set_resolution(client, 0); 357 isl29003_set_mode(client, 0); 358 isl29003_set_power_state(client, 0); 359 360 return 0; 361 } 362 363 /* 364 * I2C layer 365 */ 366 367 static int __devinit isl29003_probe(struct i2c_client *client, 368 const struct i2c_device_id *id) 369 { 370 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); 371 struct isl29003_data *data; 372 int err = 0; 373 374 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) 375 return -EIO; 376 377 data = kzalloc(sizeof(struct isl29003_data), GFP_KERNEL); 378 if (!data) 379 return -ENOMEM; 380 381 data->client = client; 382 i2c_set_clientdata(client, data); 383 mutex_init(&data->lock); 384 385 /* initialize the ISL29003 chip */ 386 err = isl29003_init_client(client); 387 if (err) 388 goto exit_kfree; 389 390 /* register sysfs hooks */ 391 err = sysfs_create_group(&client->dev.kobj, &isl29003_attr_group); 392 if (err) 393 goto exit_kfree; 394 395 dev_info(&client->dev, "driver version %s enabled\n", DRIVER_VERSION); 396 return 0; 397 398 exit_kfree: 399 kfree(data); 400 return err; 401 } 402 403 static int __devexit isl29003_remove(struct i2c_client *client) 404 { 405 sysfs_remove_group(&client->dev.kobj, &isl29003_attr_group); 406 isl29003_set_power_state(client, 0); 407 kfree(i2c_get_clientdata(client)); 408 return 0; 409 } 410 411 #ifdef CONFIG_PM 412 static int isl29003_suspend(struct i2c_client *client, pm_message_t mesg) 413 { 414 return isl29003_set_power_state(client, 0); 415 } 416 417 static int isl29003_resume(struct i2c_client *client) 418 { 419 int i; 420 struct isl29003_data *data = i2c_get_clientdata(client); 421 422 /* restore registers from cache */ 423 for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++) 424 if (!i2c_smbus_write_byte_data(client, i, data->reg_cache[i])) 425 return -EIO; 426 427 return 0; 428 } 429 430 #else 431 #define isl29003_suspend NULL 432 #define isl29003_resume NULL 433 #endif /* CONFIG_PM */ 434 435 static const struct i2c_device_id isl29003_id[] = { 436 { "isl29003", 0 }, 437 {} 438 }; 439 MODULE_DEVICE_TABLE(i2c, isl29003_id); 440 441 static struct i2c_driver isl29003_driver = { 442 .driver = { 443 .name = ISL29003_DRV_NAME, 444 .owner = THIS_MODULE, 445 }, 446 .suspend = isl29003_suspend, 447 .resume = isl29003_resume, 448 .probe = isl29003_probe, 449 .remove = __devexit_p(isl29003_remove), 450 .id_table = isl29003_id, 451 }; 452 453 static int __init isl29003_init(void) 454 { 455 return i2c_add_driver(&isl29003_driver); 456 } 457 458 static void __exit isl29003_exit(void) 459 { 460 i2c_del_driver(&isl29003_driver); 461 } 462 463 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>"); 464 MODULE_DESCRIPTION("ISL29003 ambient light sensor driver"); 465 MODULE_LICENSE("GPL v2"); 466 MODULE_VERSION(DRIVER_VERSION); 467 468 module_init(isl29003_init); 469 module_exit(isl29003_exit); 470 471