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