xref: /linux/drivers/misc/isl29003.c (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  isl29003.c - Linux kernel module for
4  * 	Intersil ISL29003 ambient light sensor
5  *
6  *  See file:Documentation/misc-devices/isl29003.rst
7  *
8  *  Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
9  *
10  *  Based on code written by
11  *  	Rodolfo Giometti <giometti@linux.it>
12  *  	Eurotech S.p.A. <info@eurotech.it>
13  */
14 
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/i2c.h>
18 #include <linux/mutex.h>
19 #include <linux/delay.h>
20 
21 #define ISL29003_DRV_NAME	"isl29003"
22 #define DRIVER_VERSION		"1.0"
23 
24 #define ISL29003_REG_COMMAND		0x00
25 #define ISL29003_ADC_ENABLED		(1 << 7)
26 #define ISL29003_ADC_PD			(1 << 6)
27 #define ISL29003_TIMING_INT		(1 << 5)
28 #define ISL29003_MODE_SHIFT		(2)
29 #define ISL29003_MODE_MASK		(0x3 << ISL29003_MODE_SHIFT)
30 #define ISL29003_RES_SHIFT		(0)
31 #define ISL29003_RES_MASK		(0x3 << ISL29003_RES_SHIFT)
32 
33 #define ISL29003_REG_CONTROL		0x01
34 #define ISL29003_INT_FLG		(1 << 5)
35 #define ISL29003_RANGE_SHIFT		(2)
36 #define ISL29003_RANGE_MASK		(0x3 << ISL29003_RANGE_SHIFT)
37 #define ISL29003_INT_PERSISTS_SHIFT	(0)
38 #define ISL29003_INT_PERSISTS_MASK	(0xf << ISL29003_INT_PERSISTS_SHIFT)
39 
40 #define ISL29003_REG_IRQ_THRESH_HI	0x02
41 #define ISL29003_REG_IRQ_THRESH_LO	0x03
42 #define ISL29003_REG_LSB_SENSOR		0x04
43 #define ISL29003_REG_MSB_SENSOR		0x05
44 #define ISL29003_REG_LSB_TIMER		0x06
45 #define ISL29003_REG_MSB_TIMER		0x07
46 
47 #define ISL29003_NUM_CACHABLE_REGS	4
48 
49 struct isl29003_data {
50 	struct i2c_client *client;
51 	struct mutex lock;
52 	u8 reg_cache[ISL29003_NUM_CACHABLE_REGS];
53 	u8 power_state_before_suspend;
54 };
55 
56 static int gain_range[] = {
57 	1000, 4000, 16000, 64000
58 };
59 
60 /*
61  * register access helpers
62  */
63 
__isl29003_read_reg(struct i2c_client * client,u32 reg,u8 mask,u8 shift)64 static int __isl29003_read_reg(struct i2c_client *client,
65 			       u32 reg, u8 mask, u8 shift)
66 {
67 	struct isl29003_data *data = i2c_get_clientdata(client);
68 
69 	return (data->reg_cache[reg] & mask) >> shift;
70 }
71 
__isl29003_write_reg(struct i2c_client * client,u32 reg,u8 mask,u8 shift,u8 val)72 static int __isl29003_write_reg(struct i2c_client *client,
73 				u32 reg, u8 mask, u8 shift, u8 val)
74 {
75 	struct isl29003_data *data = i2c_get_clientdata(client);
76 	int ret = 0;
77 	u8 tmp;
78 
79 	if (reg >= ISL29003_NUM_CACHABLE_REGS)
80 		return -EINVAL;
81 
82 	mutex_lock(&data->lock);
83 
84 	tmp = data->reg_cache[reg];
85 	tmp &= ~mask;
86 	tmp |= val << shift;
87 
88 	ret = i2c_smbus_write_byte_data(client, reg, tmp);
89 	if (!ret)
90 		data->reg_cache[reg] = tmp;
91 
92 	mutex_unlock(&data->lock);
93 	return ret;
94 }
95 
96 /*
97  * internally used functions
98  */
99 
100 /* range */
isl29003_get_range(struct i2c_client * client)101 static int isl29003_get_range(struct i2c_client *client)
102 {
103 	return __isl29003_read_reg(client, ISL29003_REG_CONTROL,
104 		ISL29003_RANGE_MASK, ISL29003_RANGE_SHIFT);
105 }
106 
isl29003_set_range(struct i2c_client * client,int range)107 static int isl29003_set_range(struct i2c_client *client, int range)
108 {
109 	return __isl29003_write_reg(client, ISL29003_REG_CONTROL,
110 		ISL29003_RANGE_MASK, ISL29003_RANGE_SHIFT, range);
111 }
112 
113 /* resolution */
isl29003_get_resolution(struct i2c_client * client)114 static int isl29003_get_resolution(struct i2c_client *client)
115 {
116 	return __isl29003_read_reg(client, ISL29003_REG_COMMAND,
117 		ISL29003_RES_MASK, ISL29003_RES_SHIFT);
118 }
119 
isl29003_set_resolution(struct i2c_client * client,int res)120 static int isl29003_set_resolution(struct i2c_client *client, int res)
121 {
122 	return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
123 		ISL29003_RES_MASK, ISL29003_RES_SHIFT, res);
124 }
125 
126 /* mode */
isl29003_get_mode(struct i2c_client * client)127 static int isl29003_get_mode(struct i2c_client *client)
128 {
129 	return __isl29003_read_reg(client, ISL29003_REG_COMMAND,
130 		ISL29003_MODE_MASK, ISL29003_MODE_SHIFT);
131 }
132 
isl29003_set_mode(struct i2c_client * client,int mode)133 static int isl29003_set_mode(struct i2c_client *client, int mode)
134 {
135 	return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
136 		ISL29003_MODE_MASK, ISL29003_MODE_SHIFT, mode);
137 }
138 
139 /* power_state */
isl29003_set_power_state(struct i2c_client * client,int state)140 static int isl29003_set_power_state(struct i2c_client *client, int state)
141 {
142 	return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
143 				ISL29003_ADC_ENABLED | ISL29003_ADC_PD, 0,
144 				state ? ISL29003_ADC_ENABLED : ISL29003_ADC_PD);
145 }
146 
isl29003_get_power_state(struct i2c_client * client)147 static int isl29003_get_power_state(struct i2c_client *client)
148 {
149 	struct isl29003_data *data = i2c_get_clientdata(client);
150 	u8 cmdreg = data->reg_cache[ISL29003_REG_COMMAND];
151 
152 	return ~cmdreg & ISL29003_ADC_PD;
153 }
154 
isl29003_get_adc_value(struct i2c_client * client)155 static int isl29003_get_adc_value(struct i2c_client *client)
156 {
157 	struct isl29003_data *data = i2c_get_clientdata(client);
158 	int lsb, msb, range, bitdepth;
159 
160 	mutex_lock(&data->lock);
161 	lsb = i2c_smbus_read_byte_data(client, ISL29003_REG_LSB_SENSOR);
162 
163 	if (lsb < 0) {
164 		mutex_unlock(&data->lock);
165 		return lsb;
166 	}
167 
168 	msb = i2c_smbus_read_byte_data(client, ISL29003_REG_MSB_SENSOR);
169 	mutex_unlock(&data->lock);
170 
171 	if (msb < 0)
172 		return msb;
173 
174 	range = isl29003_get_range(client);
175 	bitdepth = (4 - isl29003_get_resolution(client)) * 4;
176 	return (((msb << 8) | lsb) * gain_range[range]) >> bitdepth;
177 }
178 
179 /*
180  * sysfs layer
181  */
182 
183 /* range */
isl29003_show_range(struct device * dev,struct device_attribute * attr,char * buf)184 static ssize_t isl29003_show_range(struct device *dev,
185 				   struct device_attribute *attr, char *buf)
186 {
187 	struct i2c_client *client = to_i2c_client(dev);
188 
189 	return sysfs_emit(buf, "%i\n", isl29003_get_range(client));
190 }
191 
isl29003_store_range(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)192 static ssize_t isl29003_store_range(struct device *dev,
193 				    struct device_attribute *attr,
194 				    const char *buf, size_t count)
195 {
196 	struct i2c_client *client = to_i2c_client(dev);
197 	unsigned long val;
198 	int ret;
199 
200 	ret = kstrtoul(buf, 10, &val);
201 	if (ret)
202 		return ret;
203 
204 	if (val > 3)
205 		return -EINVAL;
206 
207 	ret = isl29003_set_range(client, val);
208 	if (ret < 0)
209 		return ret;
210 
211 	return count;
212 }
213 
214 static DEVICE_ATTR(range, S_IWUSR | S_IRUGO,
215 		   isl29003_show_range, isl29003_store_range);
216 
217 
218 /* resolution */
isl29003_show_resolution(struct device * dev,struct device_attribute * attr,char * buf)219 static ssize_t isl29003_show_resolution(struct device *dev,
220 					struct device_attribute *attr,
221 					char *buf)
222 {
223 	struct i2c_client *client = to_i2c_client(dev);
224 
225 	return sysfs_emit(buf, "%d\n", isl29003_get_resolution(client));
226 }
227 
isl29003_store_resolution(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)228 static ssize_t isl29003_store_resolution(struct device *dev,
229 					 struct device_attribute *attr,
230 					 const char *buf, size_t count)
231 {
232 	struct i2c_client *client = to_i2c_client(dev);
233 	unsigned long val;
234 	int ret;
235 
236 	ret = kstrtoul(buf, 10, &val);
237 	if (ret)
238 		return ret;
239 
240 	if (val > 3)
241 		return -EINVAL;
242 
243 	ret = isl29003_set_resolution(client, val);
244 	if (ret < 0)
245 		return ret;
246 
247 	return count;
248 }
249 
250 static DEVICE_ATTR(resolution, S_IWUSR | S_IRUGO,
251 		   isl29003_show_resolution, isl29003_store_resolution);
252 
253 /* mode */
isl29003_show_mode(struct device * dev,struct device_attribute * attr,char * buf)254 static ssize_t isl29003_show_mode(struct device *dev,
255 				  struct device_attribute *attr, char *buf)
256 {
257 	struct i2c_client *client = to_i2c_client(dev);
258 
259 	return sysfs_emit(buf, "%d\n", isl29003_get_mode(client));
260 }
261 
isl29003_store_mode(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)262 static ssize_t isl29003_store_mode(struct device *dev,
263 		struct device_attribute *attr, const char *buf, size_t count)
264 {
265 	struct i2c_client *client = to_i2c_client(dev);
266 	unsigned long val;
267 	int ret;
268 
269 	ret = kstrtoul(buf, 10, &val);
270 	if (ret)
271 		return ret;
272 
273 	if (val > 2)
274 		return -EINVAL;
275 
276 	ret = isl29003_set_mode(client, val);
277 	if (ret < 0)
278 		return ret;
279 
280 	return count;
281 }
282 
283 static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO,
284 		   isl29003_show_mode, isl29003_store_mode);
285 
286 
287 /* power state */
isl29003_show_power_state(struct device * dev,struct device_attribute * attr,char * buf)288 static ssize_t isl29003_show_power_state(struct device *dev,
289 					 struct device_attribute *attr,
290 					 char *buf)
291 {
292 	struct i2c_client *client = to_i2c_client(dev);
293 
294 	return sysfs_emit(buf, "%d\n", isl29003_get_power_state(client));
295 }
296 
isl29003_store_power_state(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)297 static ssize_t isl29003_store_power_state(struct device *dev,
298 					  struct device_attribute *attr,
299 					  const char *buf, size_t count)
300 {
301 	struct i2c_client *client = to_i2c_client(dev);
302 	unsigned long val;
303 	int ret;
304 
305 	ret = kstrtoul(buf, 10, &val);
306 	if (ret)
307 		return ret;
308 
309 	if (val > 1)
310 		return -EINVAL;
311 
312 	ret = isl29003_set_power_state(client, val);
313 	return ret ? ret : count;
314 }
315 
316 static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
317 		   isl29003_show_power_state, isl29003_store_power_state);
318 
319 
320 /* lux */
isl29003_show_lux(struct device * dev,struct device_attribute * attr,char * buf)321 static ssize_t isl29003_show_lux(struct device *dev,
322 				 struct device_attribute *attr, char *buf)
323 {
324 	struct i2c_client *client = to_i2c_client(dev);
325 
326 	/* No LUX data if not operational */
327 	if (!isl29003_get_power_state(client))
328 		return -EBUSY;
329 
330 	return sysfs_emit(buf, "%d\n", isl29003_get_adc_value(client));
331 }
332 
333 static DEVICE_ATTR(lux, S_IRUGO, isl29003_show_lux, NULL);
334 
335 static struct attribute *isl29003_attributes[] = {
336 	&dev_attr_range.attr,
337 	&dev_attr_resolution.attr,
338 	&dev_attr_mode.attr,
339 	&dev_attr_power_state.attr,
340 	&dev_attr_lux.attr,
341 	NULL
342 };
343 
344 static const struct attribute_group isl29003_attr_group = {
345 	.attrs = isl29003_attributes,
346 };
347 
isl29003_init_client(struct i2c_client * client)348 static int isl29003_init_client(struct i2c_client *client)
349 {
350 	struct isl29003_data *data = i2c_get_clientdata(client);
351 	int i;
352 
353 	/* read all the registers once to fill the cache.
354 	 * if one of the reads fails, we consider the init failed */
355 	for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++) {
356 		int v = i2c_smbus_read_byte_data(client, i);
357 
358 		if (v < 0)
359 			return -ENODEV;
360 
361 		data->reg_cache[i] = v;
362 	}
363 
364 	/* set defaults */
365 	isl29003_set_range(client, 0);
366 	isl29003_set_resolution(client, 0);
367 	isl29003_set_mode(client, 0);
368 	isl29003_set_power_state(client, 0);
369 
370 	return 0;
371 }
372 
373 /*
374  * I2C layer
375  */
376 
isl29003_probe(struct i2c_client * client)377 static int isl29003_probe(struct i2c_client *client)
378 {
379 	struct i2c_adapter *adapter = client->adapter;
380 	struct isl29003_data *data;
381 	int err = 0;
382 
383 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
384 		return -EIO;
385 
386 	data = kzalloc(sizeof(struct isl29003_data), GFP_KERNEL);
387 	if (!data)
388 		return -ENOMEM;
389 
390 	data->client = client;
391 	i2c_set_clientdata(client, data);
392 	mutex_init(&data->lock);
393 
394 	/* initialize the ISL29003 chip */
395 	err = isl29003_init_client(client);
396 	if (err)
397 		goto exit_kfree;
398 
399 	/* register sysfs hooks */
400 	err = sysfs_create_group(&client->dev.kobj, &isl29003_attr_group);
401 	if (err)
402 		goto exit_kfree;
403 
404 	dev_info(&client->dev, "driver version %s enabled\n", DRIVER_VERSION);
405 	return 0;
406 
407 exit_kfree:
408 	kfree(data);
409 	return err;
410 }
411 
isl29003_remove(struct i2c_client * client)412 static void isl29003_remove(struct i2c_client *client)
413 {
414 	sysfs_remove_group(&client->dev.kobj, &isl29003_attr_group);
415 	isl29003_set_power_state(client, 0);
416 	kfree(i2c_get_clientdata(client));
417 }
418 
419 #ifdef CONFIG_PM_SLEEP
isl29003_suspend(struct device * dev)420 static int isl29003_suspend(struct device *dev)
421 {
422 	struct i2c_client *client = to_i2c_client(dev);
423 	struct isl29003_data *data = i2c_get_clientdata(client);
424 
425 	data->power_state_before_suspend = isl29003_get_power_state(client);
426 	return isl29003_set_power_state(client, 0);
427 }
428 
isl29003_resume(struct device * dev)429 static int isl29003_resume(struct device *dev)
430 {
431 	int i;
432 	struct i2c_client *client = to_i2c_client(dev);
433 	struct isl29003_data *data = i2c_get_clientdata(client);
434 
435 	/* restore registers from cache */
436 	for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++)
437 		if (i2c_smbus_write_byte_data(client, i, data->reg_cache[i]))
438 			return -EIO;
439 
440 	return isl29003_set_power_state(client,
441 		data->power_state_before_suspend);
442 }
443 
444 static SIMPLE_DEV_PM_OPS(isl29003_pm_ops, isl29003_suspend, isl29003_resume);
445 #define ISL29003_PM_OPS (&isl29003_pm_ops)
446 
447 #else
448 #define ISL29003_PM_OPS NULL
449 #endif /* CONFIG_PM_SLEEP */
450 
451 static const struct i2c_device_id isl29003_id[] = {
452 	{ "isl29003" },
453 	{}
454 };
455 MODULE_DEVICE_TABLE(i2c, isl29003_id);
456 
457 static struct i2c_driver isl29003_driver = {
458 	.driver = {
459 		.name	= ISL29003_DRV_NAME,
460 		.pm	= ISL29003_PM_OPS,
461 	},
462 	.probe = isl29003_probe,
463 	.remove	= isl29003_remove,
464 	.id_table = isl29003_id,
465 };
466 
467 module_i2c_driver(isl29003_driver);
468 
469 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
470 MODULE_DESCRIPTION("ISL29003 ambient light sensor driver");
471 MODULE_LICENSE("GPL v2");
472 MODULE_VERSION(DRIVER_VERSION);
473