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 ret = kstrtoul(buf, 10, &val); 212 if (ret) 213 return ret; 214 215 if (val > 3) 216 return -EINVAL; 217 218 ret = isl29003_set_range(client, val); 219 if (ret < 0) 220 return ret; 221 222 return count; 223 } 224 225 static DEVICE_ATTR(range, S_IWUSR | S_IRUGO, 226 isl29003_show_range, isl29003_store_range); 227 228 229 /* resolution */ 230 static ssize_t isl29003_show_resolution(struct device *dev, 231 struct device_attribute *attr, 232 char *buf) 233 { 234 struct i2c_client *client = to_i2c_client(dev); 235 return sprintf(buf, "%d\n", isl29003_get_resolution(client)); 236 } 237 238 static ssize_t isl29003_store_resolution(struct device *dev, 239 struct device_attribute *attr, 240 const char *buf, size_t count) 241 { 242 struct i2c_client *client = to_i2c_client(dev); 243 unsigned long val; 244 int ret; 245 246 ret = kstrtoul(buf, 10, &val); 247 if (ret) 248 return ret; 249 250 if (val > 3) 251 return -EINVAL; 252 253 ret = isl29003_set_resolution(client, val); 254 if (ret < 0) 255 return ret; 256 257 return count; 258 } 259 260 static DEVICE_ATTR(resolution, S_IWUSR | S_IRUGO, 261 isl29003_show_resolution, isl29003_store_resolution); 262 263 /* mode */ 264 static ssize_t isl29003_show_mode(struct device *dev, 265 struct device_attribute *attr, char *buf) 266 { 267 struct i2c_client *client = to_i2c_client(dev); 268 return sprintf(buf, "%d\n", isl29003_get_mode(client)); 269 } 270 271 static ssize_t isl29003_store_mode(struct device *dev, 272 struct device_attribute *attr, const char *buf, size_t count) 273 { 274 struct i2c_client *client = to_i2c_client(dev); 275 unsigned long val; 276 int ret; 277 278 ret = kstrtoul(buf, 10, &val); 279 if (ret) 280 return ret; 281 282 if (val > 2) 283 return -EINVAL; 284 285 ret = isl29003_set_mode(client, val); 286 if (ret < 0) 287 return ret; 288 289 return count; 290 } 291 292 static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO, 293 isl29003_show_mode, isl29003_store_mode); 294 295 296 /* power state */ 297 static ssize_t isl29003_show_power_state(struct device *dev, 298 struct device_attribute *attr, 299 char *buf) 300 { 301 struct i2c_client *client = to_i2c_client(dev); 302 return sprintf(buf, "%d\n", isl29003_get_power_state(client)); 303 } 304 305 static ssize_t isl29003_store_power_state(struct device *dev, 306 struct device_attribute *attr, 307 const char *buf, size_t count) 308 { 309 struct i2c_client *client = to_i2c_client(dev); 310 unsigned long val; 311 int ret; 312 313 ret = kstrtoul(buf, 10, &val); 314 if (ret) 315 return ret; 316 317 if (val > 1) 318 return -EINVAL; 319 320 ret = isl29003_set_power_state(client, val); 321 return ret ? ret : count; 322 } 323 324 static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO, 325 isl29003_show_power_state, isl29003_store_power_state); 326 327 328 /* lux */ 329 static ssize_t isl29003_show_lux(struct device *dev, 330 struct device_attribute *attr, char *buf) 331 { 332 struct i2c_client *client = to_i2c_client(dev); 333 334 /* No LUX data if not operational */ 335 if (!isl29003_get_power_state(client)) 336 return -EBUSY; 337 338 return sprintf(buf, "%d\n", isl29003_get_adc_value(client)); 339 } 340 341 static DEVICE_ATTR(lux, S_IRUGO, isl29003_show_lux, NULL); 342 343 static struct attribute *isl29003_attributes[] = { 344 &dev_attr_range.attr, 345 &dev_attr_resolution.attr, 346 &dev_attr_mode.attr, 347 &dev_attr_power_state.attr, 348 &dev_attr_lux.attr, 349 NULL 350 }; 351 352 static const struct attribute_group isl29003_attr_group = { 353 .attrs = isl29003_attributes, 354 }; 355 356 static int isl29003_init_client(struct i2c_client *client) 357 { 358 struct isl29003_data *data = i2c_get_clientdata(client); 359 int i; 360 361 /* read all the registers once to fill the cache. 362 * if one of the reads fails, we consider the init failed */ 363 for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++) { 364 int v = i2c_smbus_read_byte_data(client, i); 365 if (v < 0) 366 return -ENODEV; 367 368 data->reg_cache[i] = v; 369 } 370 371 /* set defaults */ 372 isl29003_set_range(client, 0); 373 isl29003_set_resolution(client, 0); 374 isl29003_set_mode(client, 0); 375 isl29003_set_power_state(client, 0); 376 377 return 0; 378 } 379 380 /* 381 * I2C layer 382 */ 383 384 static int isl29003_probe(struct i2c_client *client, 385 const struct i2c_device_id *id) 386 { 387 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); 388 struct isl29003_data *data; 389 int err = 0; 390 391 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) 392 return -EIO; 393 394 data = kzalloc(sizeof(struct isl29003_data), GFP_KERNEL); 395 if (!data) 396 return -ENOMEM; 397 398 data->client = client; 399 i2c_set_clientdata(client, data); 400 mutex_init(&data->lock); 401 402 /* initialize the ISL29003 chip */ 403 err = isl29003_init_client(client); 404 if (err) 405 goto exit_kfree; 406 407 /* register sysfs hooks */ 408 err = sysfs_create_group(&client->dev.kobj, &isl29003_attr_group); 409 if (err) 410 goto exit_kfree; 411 412 dev_info(&client->dev, "driver version %s enabled\n", DRIVER_VERSION); 413 return 0; 414 415 exit_kfree: 416 kfree(data); 417 return err; 418 } 419 420 static int isl29003_remove(struct i2c_client *client) 421 { 422 sysfs_remove_group(&client->dev.kobj, &isl29003_attr_group); 423 isl29003_set_power_state(client, 0); 424 kfree(i2c_get_clientdata(client)); 425 return 0; 426 } 427 428 #ifdef CONFIG_PM_SLEEP 429 static int isl29003_suspend(struct device *dev) 430 { 431 struct i2c_client *client = to_i2c_client(dev); 432 struct isl29003_data *data = i2c_get_clientdata(client); 433 434 data->power_state_before_suspend = isl29003_get_power_state(client); 435 return isl29003_set_power_state(client, 0); 436 } 437 438 static int isl29003_resume(struct device *dev) 439 { 440 int i; 441 struct i2c_client *client = to_i2c_client(dev); 442 struct isl29003_data *data = i2c_get_clientdata(client); 443 444 /* restore registers from cache */ 445 for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++) 446 if (i2c_smbus_write_byte_data(client, i, data->reg_cache[i])) 447 return -EIO; 448 449 return isl29003_set_power_state(client, 450 data->power_state_before_suspend); 451 } 452 453 static SIMPLE_DEV_PM_OPS(isl29003_pm_ops, isl29003_suspend, isl29003_resume); 454 #define ISL29003_PM_OPS (&isl29003_pm_ops) 455 456 #else 457 #define ISL29003_PM_OPS NULL 458 #endif /* CONFIG_PM_SLEEP */ 459 460 static const struct i2c_device_id isl29003_id[] = { 461 { "isl29003", 0 }, 462 {} 463 }; 464 MODULE_DEVICE_TABLE(i2c, isl29003_id); 465 466 static struct i2c_driver isl29003_driver = { 467 .driver = { 468 .name = ISL29003_DRV_NAME, 469 .owner = THIS_MODULE, 470 .pm = ISL29003_PM_OPS, 471 }, 472 .probe = isl29003_probe, 473 .remove = isl29003_remove, 474 .id_table = isl29003_id, 475 }; 476 477 module_i2c_driver(isl29003_driver); 478 479 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>"); 480 MODULE_DESCRIPTION("ISL29003 ambient light sensor driver"); 481 MODULE_LICENSE("GPL v2"); 482 MODULE_VERSION(DRIVER_VERSION); 483