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
__isl29003_read_reg(struct i2c_client * client,u32 reg,u8 mask,u8 shift)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
__isl29003_write_reg(struct i2c_client * client,u32 reg,u8 mask,u8 shift,u8 val)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 */
isl29003_get_range(struct i2c_client * client)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
isl29003_set_range(struct i2c_client * client,int range)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 */
isl29003_get_resolution(struct i2c_client * client)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
isl29003_set_resolution(struct i2c_client * client,int res)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 */
isl29003_get_mode(struct i2c_client * client)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
isl29003_set_mode(struct i2c_client * client,int mode)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 */
isl29003_set_power_state(struct i2c_client * client,int 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
isl29003_get_power_state(struct i2c_client * client)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
isl29003_get_adc_value(struct i2c_client * client)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 */
isl29003_show_range(struct device * dev,struct device_attribute * attr,char * buf)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
isl29003_store_range(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)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 */
isl29003_show_resolution(struct device * dev,struct device_attribute * attr,char * buf)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
isl29003_store_resolution(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)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 */
isl29003_show_mode(struct device * dev,struct device_attribute * attr,char * buf)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
isl29003_store_mode(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)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 */
isl29003_show_power_state(struct device * dev,struct device_attribute * attr,char * buf)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
isl29003_store_power_state(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)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 */
isl29003_show_lux(struct device * dev,struct device_attribute * attr,char * buf)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
isl29003_init_client(struct i2c_client * client)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
isl29003_probe(struct i2c_client * client,const struct i2c_device_id * id)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
isl29003_remove(struct i2c_client * client)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
isl29003_suspend(struct device * dev)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
isl29003_resume(struct device * dev)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