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