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); 488