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 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 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 } 223 224 static DEVICE_ATTR(range, S_IWUSR | S_IRUGO, 225 isl29003_show_range, isl29003_store_range); 226 227 228 /* resolution */ 229 static 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 } 236 237 static 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 } 258 259 static DEVICE_ATTR(resolution, S_IWUSR | S_IRUGO, 260 isl29003_show_resolution, isl29003_store_resolution); 261 262 /* mode */ 263 static 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 } 269 270 static 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 } 290 291 static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO, 292 isl29003_show_mode, isl29003_store_mode); 293 294 295 /* power state */ 296 static 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 } 303 304 static 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 } 322 323 static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO, 324 isl29003_show_power_state, isl29003_store_power_state); 325 326 327 /* lux */ 328 static 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 } 339 340 static DEVICE_ATTR(lux, S_IRUGO, isl29003_show_lux, NULL); 341 342 static 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 }; 350 351 static const struct attribute_group isl29003_attr_group = { 352 .attrs = isl29003_attributes, 353 }; 354 355 static 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 */ 382 383 static 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; 413 414 exit_kfree: 415 kfree(data); 416 return err; 417 } 418 419 static 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 428 static 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 } 436 437 static 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 } 451 452 static 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 */ 458 459 static const struct i2c_device_id isl29003_id[] = { 460 { "isl29003", 0 }, 461 {} 462 }; 463 MODULE_DEVICE_TABLE(i2c, isl29003_id); 464 465 static struct i2c_driver isl29003_driver = { 466 .driver = { 467 .name = ISL29003_DRV_NAME, 468 .pm = ISL29003_PM_OPS, 469 }, 470 .probe = isl29003_probe, 471 .remove = isl29003_remove, 472 .id_table = isl29003_id, 473 }; 474 475 module_i2c_driver(isl29003_driver); 476 477 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>"); 478 MODULE_DESCRIPTION("ISL29003 ambient light sensor driver"); 479 MODULE_LICENSE("GPL v2"); 480 MODULE_VERSION(DRIVER_VERSION); 481