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 62struct 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 69static int gain_range[] = { 70 1000, 4000, 16000, 64000 71}; 72 73/* 74 * register access helpers 75 */ 76 77static 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 84static 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 */ 113static 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 119static 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 */ 126static 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 132static 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 */ 139static 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 145static 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 */ 152static 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 159static 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 166static 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 */ 195static 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 202static 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 ret = kstrtoul(buf, 10, &val); 211 if (ret) 212 return ret; 213 214 if (val > 3) 215 return -EINVAL; 216 217 ret = isl29003_set_range(client, val); 218 if (ret < 0) 219 return ret; 220 221 return count; 222} 223 224static DEVICE_ATTR(range, S_IWUSR | S_IRUGO, 225 isl29003_show_range, isl29003_store_range); 226 227 228/* resolution */ 229static ssize_t isl29003_show_resolution(struct device *dev, 230 struct device_attribute *attr, 231 char *buf) 232{ 233 struct i2c_client *client = to_i2c_client(dev); 234 return sprintf(buf, "%d\n", isl29003_get_resolution(client)); 235} 236 237static ssize_t isl29003_store_resolution(struct device *dev, 238 struct device_attribute *attr, 239 const char *buf, size_t count) 240{ 241 struct i2c_client *client = to_i2c_client(dev); 242 unsigned long val; 243 int ret; 244 245 ret = kstrtoul(buf, 10, &val); 246 if (ret) 247 return ret; 248 249 if (val > 3) 250 return -EINVAL; 251 252 ret = isl29003_set_resolution(client, val); 253 if (ret < 0) 254 return ret; 255 256 return count; 257} 258 259static DEVICE_ATTR(resolution, S_IWUSR | S_IRUGO, 260 isl29003_show_resolution, isl29003_store_resolution); 261 262/* mode */ 263static ssize_t isl29003_show_mode(struct device *dev, 264 struct device_attribute *attr, char *buf) 265{ 266 struct i2c_client *client = to_i2c_client(dev); 267 return sprintf(buf, "%d\n", isl29003_get_mode(client)); 268} 269 270static ssize_t isl29003_store_mode(struct device *dev, 271 struct device_attribute *attr, const char *buf, size_t count) 272{ 273 struct i2c_client *client = to_i2c_client(dev); 274 unsigned long val; 275 int ret; 276 277 ret = kstrtoul(buf, 10, &val); 278 if (ret) 279 return ret; 280 281 if (val > 2) 282 return -EINVAL; 283 284 ret = isl29003_set_mode(client, val); 285 if (ret < 0) 286 return ret; 287 288 return count; 289} 290 291static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO, 292 isl29003_show_mode, isl29003_store_mode); 293 294 295/* power state */ 296static ssize_t isl29003_show_power_state(struct device *dev, 297 struct device_attribute *attr, 298 char *buf) 299{ 300 struct i2c_client *client = to_i2c_client(dev); 301 return sprintf(buf, "%d\n", isl29003_get_power_state(client)); 302} 303 304static ssize_t isl29003_store_power_state(struct device *dev, 305 struct device_attribute *attr, 306 const char *buf, size_t count) 307{ 308 struct i2c_client *client = to_i2c_client(dev); 309 unsigned long val; 310 int ret; 311 312 ret = kstrtoul(buf, 10, &val); 313 if (ret) 314 return ret; 315 316 if (val > 1) 317 return -EINVAL; 318 319 ret = isl29003_set_power_state(client, val); 320 return ret ? ret : count; 321} 322 323static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO, 324 isl29003_show_power_state, isl29003_store_power_state); 325 326 327/* lux */ 328static ssize_t isl29003_show_lux(struct device *dev, 329 struct device_attribute *attr, char *buf) 330{ 331 struct i2c_client *client = to_i2c_client(dev); 332 333 /* No LUX data if not operational */ 334 if (!isl29003_get_power_state(client)) 335 return -EBUSY; 336 337 return sprintf(buf, "%d\n", isl29003_get_adc_value(client)); 338} 339 340static DEVICE_ATTR(lux, S_IRUGO, isl29003_show_lux, NULL); 341 342static struct attribute *isl29003_attributes[] = { 343 &dev_attr_range.attr, 344 &dev_attr_resolution.attr, 345 &dev_attr_mode.attr, 346 &dev_attr_power_state.attr, 347 &dev_attr_lux.attr, 348 NULL 349}; 350 351static const struct attribute_group isl29003_attr_group = { 352 .attrs = isl29003_attributes, 353}; 354 355static int isl29003_init_client(struct i2c_client *client) 356{ 357 struct isl29003_data *data = i2c_get_clientdata(client); 358 int i; 359 360 /* read all the registers once to fill the cache. 361 * if one of the reads fails, we consider the init failed */ 362 for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++) { 363 int v = i2c_smbus_read_byte_data(client, i); 364 if (v < 0) 365 return -ENODEV; 366 367 data->reg_cache[i] = v; 368 } 369 370 /* set defaults */ 371 isl29003_set_range(client, 0); 372 isl29003_set_resolution(client, 0); 373 isl29003_set_mode(client, 0); 374 isl29003_set_power_state(client, 0); 375 376 return 0; 377} 378 379/* 380 * I2C layer 381 */ 382 383static int isl29003_probe(struct i2c_client *client, 384 const struct i2c_device_id *id) 385{ 386 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); 387 struct isl29003_data *data; 388 int err = 0; 389 390 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) 391 return -EIO; 392 393 data = kzalloc(sizeof(struct isl29003_data), GFP_KERNEL); 394 if (!data) 395 return -ENOMEM; 396 397 data->client = client; 398 i2c_set_clientdata(client, data); 399 mutex_init(&data->lock); 400 401 /* initialize the ISL29003 chip */ 402 err = isl29003_init_client(client); 403 if (err) 404 goto exit_kfree; 405 406 /* register sysfs hooks */ 407 err = sysfs_create_group(&client->dev.kobj, &isl29003_attr_group); 408 if (err) 409 goto exit_kfree; 410 411 dev_info(&client->dev, "driver version %s enabled\n", DRIVER_VERSION); 412 return 0; 413 414exit_kfree: 415 kfree(data); 416 return err; 417} 418 419static int isl29003_remove(struct i2c_client *client) 420{ 421 sysfs_remove_group(&client->dev.kobj, &isl29003_attr_group); 422 isl29003_set_power_state(client, 0); 423 kfree(i2c_get_clientdata(client)); 424 return 0; 425} 426 427#ifdef CONFIG_PM_SLEEP 428static int isl29003_suspend(struct device *dev) 429{ 430 struct i2c_client *client = to_i2c_client(dev); 431 struct isl29003_data *data = i2c_get_clientdata(client); 432 433 data->power_state_before_suspend = isl29003_get_power_state(client); 434 return isl29003_set_power_state(client, 0); 435} 436 437static int isl29003_resume(struct device *dev) 438{ 439 int i; 440 struct i2c_client *client = to_i2c_client(dev); 441 struct isl29003_data *data = i2c_get_clientdata(client); 442 443 /* restore registers from cache */ 444 for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++) 445 if (i2c_smbus_write_byte_data(client, i, data->reg_cache[i])) 446 return -EIO; 447 448 return isl29003_set_power_state(client, 449 data->power_state_before_suspend); 450} 451 452static SIMPLE_DEV_PM_OPS(isl29003_pm_ops, isl29003_suspend, isl29003_resume); 453#define ISL29003_PM_OPS (&isl29003_pm_ops) 454 455#else 456#define ISL29003_PM_OPS NULL 457#endif /* CONFIG_PM_SLEEP */ 458 459static const struct i2c_device_id isl29003_id[] = { 460 { "isl29003", 0 }, 461 {} 462}; 463MODULE_DEVICE_TABLE(i2c, isl29003_id); 464 465static struct i2c_driver isl29003_driver = { 466 .driver = { 467 .name = ISL29003_DRV_NAME, 468 .owner = THIS_MODULE, 469 .pm = ISL29003_PM_OPS, 470 }, 471 .probe = isl29003_probe, 472 .remove = isl29003_remove, 473 .id_table = isl29003_id, 474}; 475 476module_i2c_driver(isl29003_driver); 477 478MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>"); 479MODULE_DESCRIPTION("ISL29003 ambient light sensor driver"); 480MODULE_LICENSE("GPL v2"); 481MODULE_VERSION(DRIVER_VERSION); 482