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Rodolfo Giomettia92c3442007-07-12 14:12:30 +02001/*
2 * tsl2550.c - Linux kernel modules for ambient light sensor
3 *
4 * Copyright (C) 2007 Rodolfo Giometti <giometti@linux.it>
5 * Copyright (C) 2007 Eurotech S.p.A. <info@eurotech.it>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22#include <linux/module.h>
23#include <linux/init.h>
24#include <linux/slab.h>
25#include <linux/i2c.h>
26#include <linux/mutex.h>
Rodolfo Giomettia92c3442007-07-12 14:12:30 +020027
28#define TSL2550_DRV_NAME "tsl2550"
Jean Delvareac780942009-09-18 22:45:44 +020029#define DRIVER_VERSION "1.2"
Rodolfo Giomettia92c3442007-07-12 14:12:30 +020030
31/*
32 * Defines
33 */
34
35#define TSL2550_POWER_DOWN 0x00
36#define TSL2550_POWER_UP 0x03
37#define TSL2550_STANDARD_RANGE 0x18
38#define TSL2550_EXTENDED_RANGE 0x1d
39#define TSL2550_READ_ADC0 0x43
40#define TSL2550_READ_ADC1 0x83
41
42/*
43 * Structs
44 */
45
46struct tsl2550_data {
47 struct i2c_client *client;
48 struct mutex update_lock;
49
Jean Delvare6a9bcce2010-03-13 20:56:54 +010050 unsigned int power_state:1;
51 unsigned int operating_mode:1;
Rodolfo Giomettia92c3442007-07-12 14:12:30 +020052};
53
54/*
55 * Global data
56 */
57
58static const u8 TSL2550_MODE_RANGE[2] = {
59 TSL2550_STANDARD_RANGE, TSL2550_EXTENDED_RANGE,
60};
61
62/*
63 * Management functions
64 */
65
66static int tsl2550_set_operating_mode(struct i2c_client *client, int mode)
67{
68 struct tsl2550_data *data = i2c_get_clientdata(client);
69
70 int ret = i2c_smbus_write_byte(client, TSL2550_MODE_RANGE[mode]);
71
72 data->operating_mode = mode;
73
74 return ret;
75}
76
77static int tsl2550_set_power_state(struct i2c_client *client, int state)
78{
79 struct tsl2550_data *data = i2c_get_clientdata(client);
80 int ret;
81
82 if (state == 0)
83 ret = i2c_smbus_write_byte(client, TSL2550_POWER_DOWN);
84 else {
85 ret = i2c_smbus_write_byte(client, TSL2550_POWER_UP);
86
87 /* On power up we should reset operating mode also... */
88 tsl2550_set_operating_mode(client, data->operating_mode);
89 }
90
91 data->power_state = state;
92
93 return ret;
94}
95
96static int tsl2550_get_adc_value(struct i2c_client *client, u8 cmd)
97{
Jean Delvareac780942009-09-18 22:45:44 +020098 int ret;
Rodolfo Giomettia92c3442007-07-12 14:12:30 +020099
Jean Delvareac780942009-09-18 22:45:44 +0200100 ret = i2c_smbus_read_byte_data(client, cmd);
101 if (ret < 0)
102 return ret;
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200103 if (!(ret & 0x80))
Jean Delvareac780942009-09-18 22:45:44 +0200104 return -EAGAIN;
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200105 return ret & 0x7f; /* remove the "valid" bit */
106}
107
108/*
109 * LUX calculation
110 */
111
112#define TSL2550_MAX_LUX 1846
113
114static const u8 ratio_lut[] = {
115 100, 100, 100, 100, 100, 100, 100, 100,
116 100, 100, 100, 100, 100, 100, 99, 99,
117 99, 99, 99, 99, 99, 99, 99, 99,
118 99, 99, 99, 98, 98, 98, 98, 98,
119 98, 98, 97, 97, 97, 97, 97, 96,
120 96, 96, 96, 95, 95, 95, 94, 94,
121 93, 93, 93, 92, 92, 91, 91, 90,
122 89, 89, 88, 87, 87, 86, 85, 84,
123 83, 82, 81, 80, 79, 78, 77, 75,
124 74, 73, 71, 69, 68, 66, 64, 62,
125 60, 58, 56, 54, 52, 49, 47, 44,
126 42, 41, 40, 40, 39, 39, 38, 38,
127 37, 37, 37, 36, 36, 36, 35, 35,
128 35, 35, 34, 34, 34, 34, 33, 33,
129 33, 33, 32, 32, 32, 32, 32, 31,
130 31, 31, 31, 31, 30, 30, 30, 30,
131 30,
132};
133
134static const u16 count_lut[] = {
135 0, 1, 2, 3, 4, 5, 6, 7,
136 8, 9, 10, 11, 12, 13, 14, 15,
137 16, 18, 20, 22, 24, 26, 28, 30,
138 32, 34, 36, 38, 40, 42, 44, 46,
139 49, 53, 57, 61, 65, 69, 73, 77,
140 81, 85, 89, 93, 97, 101, 105, 109,
141 115, 123, 131, 139, 147, 155, 163, 171,
142 179, 187, 195, 203, 211, 219, 227, 235,
143 247, 263, 279, 295, 311, 327, 343, 359,
144 375, 391, 407, 423, 439, 455, 471, 487,
145 511, 543, 575, 607, 639, 671, 703, 735,
146 767, 799, 831, 863, 895, 927, 959, 991,
147 1039, 1103, 1167, 1231, 1295, 1359, 1423, 1487,
148 1551, 1615, 1679, 1743, 1807, 1871, 1935, 1999,
149 2095, 2223, 2351, 2479, 2607, 2735, 2863, 2991,
150 3119, 3247, 3375, 3503, 3631, 3759, 3887, 4015,
151};
152
153/*
154 * This function is described into Taos TSL2550 Designer's Notebook
155 * pages 2, 3.
156 */
157static int tsl2550_calculate_lux(u8 ch0, u8 ch1)
158{
159 unsigned int lux;
160
161 /* Look up count from channel values */
162 u16 c0 = count_lut[ch0];
163 u16 c1 = count_lut[ch1];
164
165 /*
166 * Calculate ratio.
167 * Note: the "128" is a scaling factor
168 */
169 u8 r = 128;
170
171 /* Avoid division by 0 and count 1 cannot be greater than count 0 */
Michele Jr De Candia96f699a2009-07-28 16:33:03 +0200172 if (c1 <= c0)
173 if (c0) {
174 r = c1 * 128 / c0;
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200175
Michele Jr De Candia96f699a2009-07-28 16:33:03 +0200176 /* Calculate LUX */
177 lux = ((c0 - c1) * ratio_lut[r]) / 256;
178 } else
179 lux = 0;
180 else
181 return -EAGAIN;
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200182
183 /* LUX range check */
184 return lux > TSL2550_MAX_LUX ? TSL2550_MAX_LUX : lux;
185}
186
187/*
188 * SysFS support
189 */
190
191static ssize_t tsl2550_show_power_state(struct device *dev,
192 struct device_attribute *attr, char *buf)
193{
194 struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev));
195
196 return sprintf(buf, "%u\n", data->power_state);
197}
198
199static ssize_t tsl2550_store_power_state(struct device *dev,
200 struct device_attribute *attr, const char *buf, size_t count)
201{
202 struct i2c_client *client = to_i2c_client(dev);
203 struct tsl2550_data *data = i2c_get_clientdata(client);
204 unsigned long val = simple_strtoul(buf, NULL, 10);
205 int ret;
206
207 if (val < 0 || val > 1)
208 return -EINVAL;
209
210 mutex_lock(&data->update_lock);
211 ret = tsl2550_set_power_state(client, val);
212 mutex_unlock(&data->update_lock);
213
214 if (ret < 0)
215 return ret;
216
217 return count;
218}
219
220static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
221 tsl2550_show_power_state, tsl2550_store_power_state);
222
223static ssize_t tsl2550_show_operating_mode(struct device *dev,
224 struct device_attribute *attr, char *buf)
225{
226 struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev));
227
228 return sprintf(buf, "%u\n", data->operating_mode);
229}
230
231static ssize_t tsl2550_store_operating_mode(struct device *dev,
232 struct device_attribute *attr, const char *buf, size_t count)
233{
234 struct i2c_client *client = to_i2c_client(dev);
235 struct tsl2550_data *data = i2c_get_clientdata(client);
236 unsigned long val = simple_strtoul(buf, NULL, 10);
237 int ret;
238
239 if (val < 0 || val > 1)
240 return -EINVAL;
241
242 if (data->power_state == 0)
243 return -EBUSY;
244
245 mutex_lock(&data->update_lock);
246 ret = tsl2550_set_operating_mode(client, val);
247 mutex_unlock(&data->update_lock);
248
249 if (ret < 0)
250 return ret;
251
252 return count;
253}
254
255static DEVICE_ATTR(operating_mode, S_IWUSR | S_IRUGO,
256 tsl2550_show_operating_mode, tsl2550_store_operating_mode);
257
258static ssize_t __tsl2550_show_lux(struct i2c_client *client, char *buf)
259{
Michele Jr De Candia5f5bfb02009-11-26 09:22:32 +0100260 struct tsl2550_data *data = i2c_get_clientdata(client);
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200261 u8 ch0, ch1;
262 int ret;
263
264 ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC0);
265 if (ret < 0)
266 return ret;
267 ch0 = ret;
268
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200269 ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC1);
270 if (ret < 0)
271 return ret;
272 ch1 = ret;
273
274 /* Do the job */
275 ret = tsl2550_calculate_lux(ch0, ch1);
276 if (ret < 0)
277 return ret;
Michele Jr De Candia5f5bfb02009-11-26 09:22:32 +0100278 if (data->operating_mode == 1)
279 ret *= 5;
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200280
281 return sprintf(buf, "%d\n", ret);
282}
283
284static ssize_t tsl2550_show_lux1_input(struct device *dev,
285 struct device_attribute *attr, char *buf)
286{
287 struct i2c_client *client = to_i2c_client(dev);
288 struct tsl2550_data *data = i2c_get_clientdata(client);
289 int ret;
290
291 /* No LUX data if not operational */
292 if (!data->power_state)
293 return -EBUSY;
294
295 mutex_lock(&data->update_lock);
296 ret = __tsl2550_show_lux(client, buf);
297 mutex_unlock(&data->update_lock);
298
299 return ret;
300}
301
302static DEVICE_ATTR(lux1_input, S_IRUGO,
303 tsl2550_show_lux1_input, NULL);
304
305static struct attribute *tsl2550_attributes[] = {
306 &dev_attr_power_state.attr,
307 &dev_attr_operating_mode.attr,
308 &dev_attr_lux1_input.attr,
309 NULL
310};
311
312static const struct attribute_group tsl2550_attr_group = {
313 .attrs = tsl2550_attributes,
314};
315
316/*
317 * Initialization function
318 */
319
Jean Delvaree296fb72007-07-12 14:12:31 +0200320static int tsl2550_init_client(struct i2c_client *client)
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200321{
322 struct tsl2550_data *data = i2c_get_clientdata(client);
Jean Delvaree296fb72007-07-12 14:12:31 +0200323 int err;
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200324
Jean Delvaree296fb72007-07-12 14:12:31 +0200325 /*
326 * Probe the chip. To do so we try to power up the device and then to
327 * read back the 0x03 code
328 */
Jean Delvareac780942009-09-18 22:45:44 +0200329 err = i2c_smbus_read_byte_data(client, TSL2550_POWER_UP);
Jean Delvaree296fb72007-07-12 14:12:31 +0200330 if (err < 0)
331 return err;
Jean Delvareac780942009-09-18 22:45:44 +0200332 if (err != TSL2550_POWER_UP)
Jean Delvaree296fb72007-07-12 14:12:31 +0200333 return -ENODEV;
334 data->power_state = 1;
335
336 /* Set the default operating mode */
337 err = i2c_smbus_write_byte(client,
338 TSL2550_MODE_RANGE[data->operating_mode]);
339 if (err < 0)
340 return err;
341
342 return 0;
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200343}
344
345/*
346 * I2C init/probing/exit functions
347 */
348
349static struct i2c_driver tsl2550_driver;
Jean Delvared2653e92008-04-29 23:11:39 +0200350static int __devinit tsl2550_probe(struct i2c_client *client,
351 const struct i2c_device_id *id)
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200352{
353 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
354 struct tsl2550_data *data;
355 int *opmode, err = 0;
356
Jean Delvareac780942009-09-18 22:45:44 +0200357 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE
358 | I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200359 err = -EIO;
360 goto exit;
361 }
362
363 data = kzalloc(sizeof(struct tsl2550_data), GFP_KERNEL);
364 if (!data) {
365 err = -ENOMEM;
366 goto exit;
367 }
368 data->client = client;
369 i2c_set_clientdata(client, data);
370
371 /* Check platform data */
372 opmode = client->dev.platform_data;
373 if (opmode) {
374 if (*opmode < 0 || *opmode > 1) {
375 dev_err(&client->dev, "invalid operating_mode (%d)\n",
376 *opmode);
377 err = -EINVAL;
378 goto exit_kfree;
379 }
380 data->operating_mode = *opmode;
381 } else
382 data->operating_mode = 0; /* default mode is standard */
383 dev_info(&client->dev, "%s operating mode\n",
384 data->operating_mode ? "extended" : "standard");
385
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200386 mutex_init(&data->update_lock);
387
388 /* Initialize the TSL2550 chip */
Jean Delvaree296fb72007-07-12 14:12:31 +0200389 err = tsl2550_init_client(client);
390 if (err)
391 goto exit_kfree;
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200392
393 /* Register sysfs hooks */
394 err = sysfs_create_group(&client->dev.kobj, &tsl2550_attr_group);
395 if (err)
396 goto exit_kfree;
397
398 dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION);
399
400 return 0;
401
402exit_kfree:
403 kfree(data);
404exit:
405 return err;
406}
407
408static int __devexit tsl2550_remove(struct i2c_client *client)
409{
410 sysfs_remove_group(&client->dev.kobj, &tsl2550_attr_group);
411
412 /* Power down the device */
413 tsl2550_set_power_state(client, 0);
414
415 kfree(i2c_get_clientdata(client));
416
417 return 0;
418}
419
Rodolfo Giometti1b3e5ba2008-01-27 18:14:45 +0100420#ifdef CONFIG_PM
421
422static int tsl2550_suspend(struct i2c_client *client, pm_message_t mesg)
423{
424 return tsl2550_set_power_state(client, 0);
425}
426
427static int tsl2550_resume(struct i2c_client *client)
428{
429 return tsl2550_set_power_state(client, 1);
430}
431
432#else
433
434#define tsl2550_suspend NULL
435#define tsl2550_resume NULL
436
437#endif /* CONFIG_PM */
438
Jean Delvare3760f732008-04-29 23:11:40 +0200439static const struct i2c_device_id tsl2550_id[] = {
440 { "tsl2550", 0 },
441 { }
442};
443MODULE_DEVICE_TABLE(i2c, tsl2550_id);
444
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200445static struct i2c_driver tsl2550_driver = {
446 .driver = {
447 .name = TSL2550_DRV_NAME,
448 .owner = THIS_MODULE,
449 },
Rodolfo Giometti1b3e5ba2008-01-27 18:14:45 +0100450 .suspend = tsl2550_suspend,
451 .resume = tsl2550_resume,
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200452 .probe = tsl2550_probe,
453 .remove = __devexit_p(tsl2550_remove),
Jean Delvare3760f732008-04-29 23:11:40 +0200454 .id_table = tsl2550_id,
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200455};
456
Axel Lina64fe2e2012-01-22 15:36:45 +0800457module_i2c_driver(tsl2550_driver);
Rodolfo Giomettia92c3442007-07-12 14:12:30 +0200458
459MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
460MODULE_DESCRIPTION("TSL2550 ambient light sensor driver");
461MODULE_LICENSE("GPL");
Jean Delvaree296fb72007-07-12 14:12:31 +0200462MODULE_VERSION(DRIVER_VERSION);