Commit | Line | Data |
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a92c344d RG |
1 | /* |
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> | |
a92c344d RG |
23 | #include <linux/slab.h> |
24 | #include <linux/i2c.h> | |
25 | #include <linux/mutex.h> | |
a92c344d RG |
26 | |
27 | #define TSL2550_DRV_NAME "tsl2550" | |
ac780941 | 28 | #define DRIVER_VERSION "1.2" |
a92c344d RG |
29 | |
30 | /* | |
31 | * Defines | |
32 | */ | |
33 | ||
34 | #define TSL2550_POWER_DOWN 0x00 | |
35 | #define TSL2550_POWER_UP 0x03 | |
36 | #define TSL2550_STANDARD_RANGE 0x18 | |
37 | #define TSL2550_EXTENDED_RANGE 0x1d | |
38 | #define TSL2550_READ_ADC0 0x43 | |
39 | #define TSL2550_READ_ADC1 0x83 | |
40 | ||
41 | /* | |
42 | * Structs | |
43 | */ | |
44 | ||
45 | struct tsl2550_data { | |
46 | struct i2c_client *client; | |
47 | struct mutex update_lock; | |
48 | ||
6a9bcced JD |
49 | unsigned int power_state:1; |
50 | unsigned int operating_mode:1; | |
a92c344d RG |
51 | }; |
52 | ||
53 | /* | |
54 | * Global data | |
55 | */ | |
56 | ||
57 | static const u8 TSL2550_MODE_RANGE[2] = { | |
58 | TSL2550_STANDARD_RANGE, TSL2550_EXTENDED_RANGE, | |
59 | }; | |
60 | ||
61 | /* | |
62 | * Management functions | |
63 | */ | |
64 | ||
65 | static int tsl2550_set_operating_mode(struct i2c_client *client, int mode) | |
66 | { | |
67 | struct tsl2550_data *data = i2c_get_clientdata(client); | |
68 | ||
69 | int ret = i2c_smbus_write_byte(client, TSL2550_MODE_RANGE[mode]); | |
70 | ||
71 | data->operating_mode = mode; | |
72 | ||
73 | return ret; | |
74 | } | |
75 | ||
76 | static int tsl2550_set_power_state(struct i2c_client *client, int state) | |
77 | { | |
78 | struct tsl2550_data *data = i2c_get_clientdata(client); | |
79 | int ret; | |
80 | ||
81 | if (state == 0) | |
82 | ret = i2c_smbus_write_byte(client, TSL2550_POWER_DOWN); | |
83 | else { | |
84 | ret = i2c_smbus_write_byte(client, TSL2550_POWER_UP); | |
85 | ||
86 | /* On power up we should reset operating mode also... */ | |
87 | tsl2550_set_operating_mode(client, data->operating_mode); | |
88 | } | |
89 | ||
90 | data->power_state = state; | |
91 | ||
92 | return ret; | |
93 | } | |
94 | ||
95 | static int tsl2550_get_adc_value(struct i2c_client *client, u8 cmd) | |
96 | { | |
ac780941 | 97 | int ret; |
a92c344d | 98 | |
ac780941 JD |
99 | ret = i2c_smbus_read_byte_data(client, cmd); |
100 | if (ret < 0) | |
101 | return ret; | |
a92c344d | 102 | if (!(ret & 0x80)) |
ac780941 | 103 | return -EAGAIN; |
a92c344d RG |
104 | return ret & 0x7f; /* remove the "valid" bit */ |
105 | } | |
106 | ||
107 | /* | |
108 | * LUX calculation | |
109 | */ | |
110 | ||
111 | #define TSL2550_MAX_LUX 1846 | |
112 | ||
113 | static const u8 ratio_lut[] = { | |
114 | 100, 100, 100, 100, 100, 100, 100, 100, | |
115 | 100, 100, 100, 100, 100, 100, 99, 99, | |
116 | 99, 99, 99, 99, 99, 99, 99, 99, | |
117 | 99, 99, 99, 98, 98, 98, 98, 98, | |
118 | 98, 98, 97, 97, 97, 97, 97, 96, | |
119 | 96, 96, 96, 95, 95, 95, 94, 94, | |
120 | 93, 93, 93, 92, 92, 91, 91, 90, | |
121 | 89, 89, 88, 87, 87, 86, 85, 84, | |
122 | 83, 82, 81, 80, 79, 78, 77, 75, | |
123 | 74, 73, 71, 69, 68, 66, 64, 62, | |
124 | 60, 58, 56, 54, 52, 49, 47, 44, | |
125 | 42, 41, 40, 40, 39, 39, 38, 38, | |
126 | 37, 37, 37, 36, 36, 36, 35, 35, | |
127 | 35, 35, 34, 34, 34, 34, 33, 33, | |
128 | 33, 33, 32, 32, 32, 32, 32, 31, | |
129 | 31, 31, 31, 31, 30, 30, 30, 30, | |
130 | 30, | |
131 | }; | |
132 | ||
133 | static const u16 count_lut[] = { | |
134 | 0, 1, 2, 3, 4, 5, 6, 7, | |
135 | 8, 9, 10, 11, 12, 13, 14, 15, | |
136 | 16, 18, 20, 22, 24, 26, 28, 30, | |
137 | 32, 34, 36, 38, 40, 42, 44, 46, | |
138 | 49, 53, 57, 61, 65, 69, 73, 77, | |
139 | 81, 85, 89, 93, 97, 101, 105, 109, | |
140 | 115, 123, 131, 139, 147, 155, 163, 171, | |
141 | 179, 187, 195, 203, 211, 219, 227, 235, | |
142 | 247, 263, 279, 295, 311, 327, 343, 359, | |
143 | 375, 391, 407, 423, 439, 455, 471, 487, | |
144 | 511, 543, 575, 607, 639, 671, 703, 735, | |
145 | 767, 799, 831, 863, 895, 927, 959, 991, | |
146 | 1039, 1103, 1167, 1231, 1295, 1359, 1423, 1487, | |
147 | 1551, 1615, 1679, 1743, 1807, 1871, 1935, 1999, | |
148 | 2095, 2223, 2351, 2479, 2607, 2735, 2863, 2991, | |
149 | 3119, 3247, 3375, 3503, 3631, 3759, 3887, 4015, | |
150 | }; | |
151 | ||
152 | /* | |
153 | * This function is described into Taos TSL2550 Designer's Notebook | |
154 | * pages 2, 3. | |
155 | */ | |
156 | static int tsl2550_calculate_lux(u8 ch0, u8 ch1) | |
157 | { | |
158 | unsigned int lux; | |
159 | ||
160 | /* Look up count from channel values */ | |
161 | u16 c0 = count_lut[ch0]; | |
162 | u16 c1 = count_lut[ch1]; | |
163 | ||
164 | /* | |
165 | * Calculate ratio. | |
166 | * Note: the "128" is a scaling factor | |
167 | */ | |
168 | u8 r = 128; | |
169 | ||
170 | /* Avoid division by 0 and count 1 cannot be greater than count 0 */ | |
96f699ad MJDC |
171 | if (c1 <= c0) |
172 | if (c0) { | |
173 | r = c1 * 128 / c0; | |
174 | ||
175 | /* Calculate LUX */ | |
176 | lux = ((c0 - c1) * ratio_lut[r]) / 256; | |
177 | } else | |
178 | lux = 0; | |
a92c344d | 179 | else |
96f699ad | 180 | return -EAGAIN; |
a92c344d RG |
181 | |
182 | /* LUX range check */ | |
183 | return lux > TSL2550_MAX_LUX ? TSL2550_MAX_LUX : lux; | |
184 | } | |
185 | ||
186 | /* | |
187 | * SysFS support | |
188 | */ | |
189 | ||
190 | static ssize_t tsl2550_show_power_state(struct device *dev, | |
191 | struct device_attribute *attr, char *buf) | |
192 | { | |
193 | struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev)); | |
194 | ||
195 | return sprintf(buf, "%u\n", data->power_state); | |
196 | } | |
197 | ||
198 | static ssize_t tsl2550_store_power_state(struct device *dev, | |
199 | struct device_attribute *attr, const char *buf, size_t count) | |
200 | { | |
201 | struct i2c_client *client = to_i2c_client(dev); | |
202 | struct tsl2550_data *data = i2c_get_clientdata(client); | |
203 | unsigned long val = simple_strtoul(buf, NULL, 10); | |
204 | int ret; | |
205 | ||
ae8a35ae | 206 | if (val > 1) |
a92c344d RG |
207 | return -EINVAL; |
208 | ||
209 | mutex_lock(&data->update_lock); | |
210 | ret = tsl2550_set_power_state(client, val); | |
211 | mutex_unlock(&data->update_lock); | |
212 | ||
213 | if (ret < 0) | |
214 | return ret; | |
215 | ||
216 | return count; | |
217 | } | |
218 | ||
219 | static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO, | |
220 | tsl2550_show_power_state, tsl2550_store_power_state); | |
221 | ||
222 | static ssize_t tsl2550_show_operating_mode(struct device *dev, | |
223 | struct device_attribute *attr, char *buf) | |
224 | { | |
225 | struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev)); | |
226 | ||
227 | return sprintf(buf, "%u\n", data->operating_mode); | |
228 | } | |
229 | ||
230 | static ssize_t tsl2550_store_operating_mode(struct device *dev, | |
231 | struct device_attribute *attr, const char *buf, size_t count) | |
232 | { | |
233 | struct i2c_client *client = to_i2c_client(dev); | |
234 | struct tsl2550_data *data = i2c_get_clientdata(client); | |
235 | unsigned long val = simple_strtoul(buf, NULL, 10); | |
236 | int ret; | |
237 | ||
ae8a35ae | 238 | if (val > 1) |
a92c344d RG |
239 | return -EINVAL; |
240 | ||
241 | if (data->power_state == 0) | |
242 | return -EBUSY; | |
243 | ||
244 | mutex_lock(&data->update_lock); | |
245 | ret = tsl2550_set_operating_mode(client, val); | |
246 | mutex_unlock(&data->update_lock); | |
247 | ||
248 | if (ret < 0) | |
249 | return ret; | |
250 | ||
251 | return count; | |
252 | } | |
253 | ||
254 | static DEVICE_ATTR(operating_mode, S_IWUSR | S_IRUGO, | |
255 | tsl2550_show_operating_mode, tsl2550_store_operating_mode); | |
256 | ||
257 | static ssize_t __tsl2550_show_lux(struct i2c_client *client, char *buf) | |
258 | { | |
5f5bfb09 | 259 | struct tsl2550_data *data = i2c_get_clientdata(client); |
a92c344d RG |
260 | u8 ch0, ch1; |
261 | int ret; | |
262 | ||
263 | ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC0); | |
264 | if (ret < 0) | |
265 | return ret; | |
266 | ch0 = ret; | |
267 | ||
a92c344d RG |
268 | ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC1); |
269 | if (ret < 0) | |
270 | return ret; | |
271 | ch1 = ret; | |
272 | ||
273 | /* Do the job */ | |
274 | ret = tsl2550_calculate_lux(ch0, ch1); | |
275 | if (ret < 0) | |
276 | return ret; | |
5f5bfb09 MJDC |
277 | if (data->operating_mode == 1) |
278 | ret *= 5; | |
a92c344d RG |
279 | |
280 | return sprintf(buf, "%d\n", ret); | |
281 | } | |
282 | ||
283 | static ssize_t tsl2550_show_lux1_input(struct device *dev, | |
284 | struct device_attribute *attr, char *buf) | |
285 | { | |
286 | struct i2c_client *client = to_i2c_client(dev); | |
287 | struct tsl2550_data *data = i2c_get_clientdata(client); | |
288 | int ret; | |
289 | ||
290 | /* No LUX data if not operational */ | |
291 | if (!data->power_state) | |
292 | return -EBUSY; | |
293 | ||
294 | mutex_lock(&data->update_lock); | |
295 | ret = __tsl2550_show_lux(client, buf); | |
296 | mutex_unlock(&data->update_lock); | |
297 | ||
298 | return ret; | |
299 | } | |
300 | ||
301 | static DEVICE_ATTR(lux1_input, S_IRUGO, | |
302 | tsl2550_show_lux1_input, NULL); | |
303 | ||
304 | static struct attribute *tsl2550_attributes[] = { | |
305 | &dev_attr_power_state.attr, | |
306 | &dev_attr_operating_mode.attr, | |
307 | &dev_attr_lux1_input.attr, | |
308 | NULL | |
309 | }; | |
310 | ||
311 | static const struct attribute_group tsl2550_attr_group = { | |
312 | .attrs = tsl2550_attributes, | |
313 | }; | |
314 | ||
315 | /* | |
316 | * Initialization function | |
317 | */ | |
318 | ||
e296fb7f | 319 | static int tsl2550_init_client(struct i2c_client *client) |
a92c344d RG |
320 | { |
321 | struct tsl2550_data *data = i2c_get_clientdata(client); | |
e296fb7f | 322 | int err; |
a92c344d | 323 | |
e296fb7f JD |
324 | /* |
325 | * Probe the chip. To do so we try to power up the device and then to | |
326 | * read back the 0x03 code | |
327 | */ | |
ac780941 | 328 | err = i2c_smbus_read_byte_data(client, TSL2550_POWER_UP); |
e296fb7f JD |
329 | if (err < 0) |
330 | return err; | |
ac780941 | 331 | if (err != TSL2550_POWER_UP) |
e296fb7f JD |
332 | return -ENODEV; |
333 | data->power_state = 1; | |
334 | ||
335 | /* Set the default operating mode */ | |
336 | err = i2c_smbus_write_byte(client, | |
337 | TSL2550_MODE_RANGE[data->operating_mode]); | |
338 | if (err < 0) | |
339 | return err; | |
340 | ||
341 | return 0; | |
a92c344d RG |
342 | } |
343 | ||
344 | /* | |
345 | * I2C init/probing/exit functions | |
346 | */ | |
347 | ||
348 | static struct i2c_driver tsl2550_driver; | |
80c8ae28 | 349 | static int tsl2550_probe(struct i2c_client *client, |
d2653e92 | 350 | const struct i2c_device_id *id) |
a92c344d RG |
351 | { |
352 | struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); | |
353 | struct tsl2550_data *data; | |
354 | int *opmode, err = 0; | |
355 | ||
ac780941 JD |
356 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE |
357 | | I2C_FUNC_SMBUS_READ_BYTE_DATA)) { | |
a92c344d RG |
358 | err = -EIO; |
359 | goto exit; | |
360 | } | |
361 | ||
362 | data = kzalloc(sizeof(struct tsl2550_data), GFP_KERNEL); | |
363 | if (!data) { | |
364 | err = -ENOMEM; | |
365 | goto exit; | |
366 | } | |
367 | data->client = client; | |
368 | i2c_set_clientdata(client, data); | |
369 | ||
370 | /* Check platform data */ | |
371 | opmode = client->dev.platform_data; | |
372 | if (opmode) { | |
373 | if (*opmode < 0 || *opmode > 1) { | |
374 | dev_err(&client->dev, "invalid operating_mode (%d)\n", | |
375 | *opmode); | |
376 | err = -EINVAL; | |
377 | goto exit_kfree; | |
378 | } | |
379 | data->operating_mode = *opmode; | |
380 | } else | |
381 | data->operating_mode = 0; /* default mode is standard */ | |
382 | dev_info(&client->dev, "%s operating mode\n", | |
383 | data->operating_mode ? "extended" : "standard"); | |
384 | ||
a92c344d RG |
385 | mutex_init(&data->update_lock); |
386 | ||
387 | /* Initialize the TSL2550 chip */ | |
e296fb7f JD |
388 | err = tsl2550_init_client(client); |
389 | if (err) | |
390 | goto exit_kfree; | |
a92c344d RG |
391 | |
392 | /* Register sysfs hooks */ | |
393 | err = sysfs_create_group(&client->dev.kobj, &tsl2550_attr_group); | |
394 | if (err) | |
395 | goto exit_kfree; | |
396 | ||
397 | dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION); | |
398 | ||
399 | return 0; | |
400 | ||
401 | exit_kfree: | |
402 | kfree(data); | |
403 | exit: | |
404 | return err; | |
405 | } | |
406 | ||
486a5c28 | 407 | static int tsl2550_remove(struct i2c_client *client) |
a92c344d RG |
408 | { |
409 | sysfs_remove_group(&client->dev.kobj, &tsl2550_attr_group); | |
410 | ||
411 | /* Power down the device */ | |
412 | tsl2550_set_power_state(client, 0); | |
413 | ||
414 | kfree(i2c_get_clientdata(client)); | |
415 | ||
416 | return 0; | |
417 | } | |
418 | ||
a7761027 | 419 | #ifdef CONFIG_PM_SLEEP |
1b3e5baa | 420 | |
a7761027 | 421 | static int tsl2550_suspend(struct device *dev) |
1b3e5baa | 422 | { |
a7761027 | 423 | return tsl2550_set_power_state(to_i2c_client(dev), 0); |
1b3e5baa RG |
424 | } |
425 | ||
a7761027 | 426 | static int tsl2550_resume(struct device *dev) |
1b3e5baa | 427 | { |
a7761027 | 428 | return tsl2550_set_power_state(to_i2c_client(dev), 1); |
1b3e5baa RG |
429 | } |
430 | ||
a7761027 LPC |
431 | static SIMPLE_DEV_PM_OPS(tsl2550_pm_ops, tsl2550_suspend, tsl2550_resume); |
432 | #define TSL2550_PM_OPS (&tsl2550_pm_ops) | |
433 | ||
1b3e5baa RG |
434 | #else |
435 | ||
a7761027 | 436 | #define TSL2550_PM_OPS NULL |
1b3e5baa | 437 | |
a7761027 | 438 | #endif /* CONFIG_PM_SLEEP */ |
1b3e5baa | 439 | |
3760f736 JD |
440 | static const struct i2c_device_id tsl2550_id[] = { |
441 | { "tsl2550", 0 }, | |
442 | { } | |
443 | }; | |
444 | MODULE_DEVICE_TABLE(i2c, tsl2550_id); | |
445 | ||
a92c344d RG |
446 | static struct i2c_driver tsl2550_driver = { |
447 | .driver = { | |
448 | .name = TSL2550_DRV_NAME, | |
a7761027 | 449 | .pm = TSL2550_PM_OPS, |
a92c344d RG |
450 | }, |
451 | .probe = tsl2550_probe, | |
2d6bed9c | 452 | .remove = tsl2550_remove, |
3760f736 | 453 | .id_table = tsl2550_id, |
a92c344d RG |
454 | }; |
455 | ||
a64fe2ed | 456 | module_i2c_driver(tsl2550_driver); |
a92c344d RG |
457 | |
458 | MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>"); | |
459 | MODULE_DESCRIPTION("TSL2550 ambient light sensor driver"); | |
460 | MODULE_LICENSE("GPL"); | |
e296fb7f | 461 | MODULE_VERSION(DRIVER_VERSION); |