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74ba9207 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
a92c344d RG |
2 | /* |
3 | * tsl2550.c - Linux kernel modules for ambient light sensor | |
4 | * | |
5 | * Copyright (C) 2007 Rodolfo Giometti <giometti@linux.it> | |
6 | * Copyright (C) 2007 Eurotech S.p.A. <info@eurotech.it> | |
a92c344d RG |
7 | */ |
8 | ||
9 | #include <linux/module.h> | |
a92c344d RG |
10 | #include <linux/slab.h> |
11 | #include <linux/i2c.h> | |
12 | #include <linux/mutex.h> | |
a92c344d RG |
13 | |
14 | #define TSL2550_DRV_NAME "tsl2550" | |
ac780941 | 15 | #define DRIVER_VERSION "1.2" |
a92c344d RG |
16 | |
17 | /* | |
18 | * Defines | |
19 | */ | |
20 | ||
21 | #define TSL2550_POWER_DOWN 0x00 | |
22 | #define TSL2550_POWER_UP 0x03 | |
23 | #define TSL2550_STANDARD_RANGE 0x18 | |
24 | #define TSL2550_EXTENDED_RANGE 0x1d | |
25 | #define TSL2550_READ_ADC0 0x43 | |
26 | #define TSL2550_READ_ADC1 0x83 | |
27 | ||
28 | /* | |
29 | * Structs | |
30 | */ | |
31 | ||
32 | struct tsl2550_data { | |
33 | struct i2c_client *client; | |
34 | struct mutex update_lock; | |
35 | ||
6a9bcced JD |
36 | unsigned int power_state:1; |
37 | unsigned int operating_mode:1; | |
a92c344d RG |
38 | }; |
39 | ||
40 | /* | |
41 | * Global data | |
42 | */ | |
43 | ||
44 | static const u8 TSL2550_MODE_RANGE[2] = { | |
45 | TSL2550_STANDARD_RANGE, TSL2550_EXTENDED_RANGE, | |
46 | }; | |
47 | ||
48 | /* | |
49 | * Management functions | |
50 | */ | |
51 | ||
52 | static int tsl2550_set_operating_mode(struct i2c_client *client, int mode) | |
53 | { | |
54 | struct tsl2550_data *data = i2c_get_clientdata(client); | |
55 | ||
56 | int ret = i2c_smbus_write_byte(client, TSL2550_MODE_RANGE[mode]); | |
57 | ||
58 | data->operating_mode = mode; | |
59 | ||
60 | return ret; | |
61 | } | |
62 | ||
63 | static int tsl2550_set_power_state(struct i2c_client *client, int state) | |
64 | { | |
65 | struct tsl2550_data *data = i2c_get_clientdata(client); | |
66 | int ret; | |
67 | ||
68 | if (state == 0) | |
69 | ret = i2c_smbus_write_byte(client, TSL2550_POWER_DOWN); | |
70 | else { | |
71 | ret = i2c_smbus_write_byte(client, TSL2550_POWER_UP); | |
72 | ||
73 | /* On power up we should reset operating mode also... */ | |
74 | tsl2550_set_operating_mode(client, data->operating_mode); | |
75 | } | |
76 | ||
77 | data->power_state = state; | |
78 | ||
79 | return ret; | |
80 | } | |
81 | ||
82 | static int tsl2550_get_adc_value(struct i2c_client *client, u8 cmd) | |
83 | { | |
ac780941 | 84 | int ret; |
a92c344d | 85 | |
ac780941 JD |
86 | ret = i2c_smbus_read_byte_data(client, cmd); |
87 | if (ret < 0) | |
88 | return ret; | |
a92c344d | 89 | if (!(ret & 0x80)) |
ac780941 | 90 | return -EAGAIN; |
a92c344d RG |
91 | return ret & 0x7f; /* remove the "valid" bit */ |
92 | } | |
93 | ||
94 | /* | |
95 | * LUX calculation | |
96 | */ | |
97 | ||
98 | #define TSL2550_MAX_LUX 1846 | |
99 | ||
100 | static const u8 ratio_lut[] = { | |
101 | 100, 100, 100, 100, 100, 100, 100, 100, | |
102 | 100, 100, 100, 100, 100, 100, 99, 99, | |
103 | 99, 99, 99, 99, 99, 99, 99, 99, | |
104 | 99, 99, 99, 98, 98, 98, 98, 98, | |
105 | 98, 98, 97, 97, 97, 97, 97, 96, | |
106 | 96, 96, 96, 95, 95, 95, 94, 94, | |
107 | 93, 93, 93, 92, 92, 91, 91, 90, | |
108 | 89, 89, 88, 87, 87, 86, 85, 84, | |
109 | 83, 82, 81, 80, 79, 78, 77, 75, | |
110 | 74, 73, 71, 69, 68, 66, 64, 62, | |
111 | 60, 58, 56, 54, 52, 49, 47, 44, | |
112 | 42, 41, 40, 40, 39, 39, 38, 38, | |
113 | 37, 37, 37, 36, 36, 36, 35, 35, | |
114 | 35, 35, 34, 34, 34, 34, 33, 33, | |
115 | 33, 33, 32, 32, 32, 32, 32, 31, | |
116 | 31, 31, 31, 31, 30, 30, 30, 30, | |
117 | 30, | |
118 | }; | |
119 | ||
120 | static const u16 count_lut[] = { | |
121 | 0, 1, 2, 3, 4, 5, 6, 7, | |
122 | 8, 9, 10, 11, 12, 13, 14, 15, | |
123 | 16, 18, 20, 22, 24, 26, 28, 30, | |
124 | 32, 34, 36, 38, 40, 42, 44, 46, | |
125 | 49, 53, 57, 61, 65, 69, 73, 77, | |
126 | 81, 85, 89, 93, 97, 101, 105, 109, | |
127 | 115, 123, 131, 139, 147, 155, 163, 171, | |
128 | 179, 187, 195, 203, 211, 219, 227, 235, | |
129 | 247, 263, 279, 295, 311, 327, 343, 359, | |
130 | 375, 391, 407, 423, 439, 455, 471, 487, | |
131 | 511, 543, 575, 607, 639, 671, 703, 735, | |
132 | 767, 799, 831, 863, 895, 927, 959, 991, | |
133 | 1039, 1103, 1167, 1231, 1295, 1359, 1423, 1487, | |
134 | 1551, 1615, 1679, 1743, 1807, 1871, 1935, 1999, | |
135 | 2095, 2223, 2351, 2479, 2607, 2735, 2863, 2991, | |
136 | 3119, 3247, 3375, 3503, 3631, 3759, 3887, 4015, | |
137 | }; | |
138 | ||
139 | /* | |
140 | * This function is described into Taos TSL2550 Designer's Notebook | |
141 | * pages 2, 3. | |
142 | */ | |
143 | static int tsl2550_calculate_lux(u8 ch0, u8 ch1) | |
144 | { | |
145 | unsigned int lux; | |
146 | ||
147 | /* Look up count from channel values */ | |
148 | u16 c0 = count_lut[ch0]; | |
149 | u16 c1 = count_lut[ch1]; | |
150 | ||
151 | /* | |
152 | * Calculate ratio. | |
153 | * Note: the "128" is a scaling factor | |
154 | */ | |
155 | u8 r = 128; | |
156 | ||
157 | /* Avoid division by 0 and count 1 cannot be greater than count 0 */ | |
96f699ad MJDC |
158 | if (c1 <= c0) |
159 | if (c0) { | |
160 | r = c1 * 128 / c0; | |
161 | ||
162 | /* Calculate LUX */ | |
163 | lux = ((c0 - c1) * ratio_lut[r]) / 256; | |
164 | } else | |
165 | lux = 0; | |
a92c344d | 166 | else |
ce054546 | 167 | return 0; |
a92c344d RG |
168 | |
169 | /* LUX range check */ | |
170 | return lux > TSL2550_MAX_LUX ? TSL2550_MAX_LUX : lux; | |
171 | } | |
172 | ||
173 | /* | |
174 | * SysFS support | |
175 | */ | |
176 | ||
177 | static ssize_t tsl2550_show_power_state(struct device *dev, | |
178 | struct device_attribute *attr, char *buf) | |
179 | { | |
180 | struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev)); | |
181 | ||
182 | return sprintf(buf, "%u\n", data->power_state); | |
183 | } | |
184 | ||
185 | static ssize_t tsl2550_store_power_state(struct device *dev, | |
186 | struct device_attribute *attr, const char *buf, size_t count) | |
187 | { | |
188 | struct i2c_client *client = to_i2c_client(dev); | |
189 | struct tsl2550_data *data = i2c_get_clientdata(client); | |
190 | unsigned long val = simple_strtoul(buf, NULL, 10); | |
191 | int ret; | |
192 | ||
ae8a35ae | 193 | if (val > 1) |
a92c344d RG |
194 | return -EINVAL; |
195 | ||
196 | mutex_lock(&data->update_lock); | |
197 | ret = tsl2550_set_power_state(client, val); | |
198 | mutex_unlock(&data->update_lock); | |
199 | ||
200 | if (ret < 0) | |
201 | return ret; | |
202 | ||
203 | return count; | |
204 | } | |
205 | ||
206 | static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO, | |
207 | tsl2550_show_power_state, tsl2550_store_power_state); | |
208 | ||
209 | static ssize_t tsl2550_show_operating_mode(struct device *dev, | |
210 | struct device_attribute *attr, char *buf) | |
211 | { | |
212 | struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev)); | |
213 | ||
214 | return sprintf(buf, "%u\n", data->operating_mode); | |
215 | } | |
216 | ||
217 | static ssize_t tsl2550_store_operating_mode(struct device *dev, | |
218 | struct device_attribute *attr, const char *buf, size_t count) | |
219 | { | |
220 | struct i2c_client *client = to_i2c_client(dev); | |
221 | struct tsl2550_data *data = i2c_get_clientdata(client); | |
222 | unsigned long val = simple_strtoul(buf, NULL, 10); | |
223 | int ret; | |
224 | ||
ae8a35ae | 225 | if (val > 1) |
a92c344d RG |
226 | return -EINVAL; |
227 | ||
228 | if (data->power_state == 0) | |
229 | return -EBUSY; | |
230 | ||
231 | mutex_lock(&data->update_lock); | |
232 | ret = tsl2550_set_operating_mode(client, val); | |
233 | mutex_unlock(&data->update_lock); | |
234 | ||
235 | if (ret < 0) | |
236 | return ret; | |
237 | ||
238 | return count; | |
239 | } | |
240 | ||
241 | static DEVICE_ATTR(operating_mode, S_IWUSR | S_IRUGO, | |
242 | tsl2550_show_operating_mode, tsl2550_store_operating_mode); | |
243 | ||
244 | static ssize_t __tsl2550_show_lux(struct i2c_client *client, char *buf) | |
245 | { | |
5f5bfb09 | 246 | struct tsl2550_data *data = i2c_get_clientdata(client); |
a92c344d RG |
247 | u8 ch0, ch1; |
248 | int ret; | |
249 | ||
250 | ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC0); | |
251 | if (ret < 0) | |
252 | return ret; | |
253 | ch0 = ret; | |
254 | ||
a92c344d RG |
255 | ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC1); |
256 | if (ret < 0) | |
257 | return ret; | |
258 | ch1 = ret; | |
259 | ||
260 | /* Do the job */ | |
261 | ret = tsl2550_calculate_lux(ch0, ch1); | |
262 | if (ret < 0) | |
263 | return ret; | |
5f5bfb09 MJDC |
264 | if (data->operating_mode == 1) |
265 | ret *= 5; | |
a92c344d RG |
266 | |
267 | return sprintf(buf, "%d\n", ret); | |
268 | } | |
269 | ||
270 | static ssize_t tsl2550_show_lux1_input(struct device *dev, | |
271 | struct device_attribute *attr, char *buf) | |
272 | { | |
273 | struct i2c_client *client = to_i2c_client(dev); | |
274 | struct tsl2550_data *data = i2c_get_clientdata(client); | |
275 | int ret; | |
276 | ||
277 | /* No LUX data if not operational */ | |
278 | if (!data->power_state) | |
279 | return -EBUSY; | |
280 | ||
281 | mutex_lock(&data->update_lock); | |
282 | ret = __tsl2550_show_lux(client, buf); | |
283 | mutex_unlock(&data->update_lock); | |
284 | ||
285 | return ret; | |
286 | } | |
287 | ||
288 | static DEVICE_ATTR(lux1_input, S_IRUGO, | |
289 | tsl2550_show_lux1_input, NULL); | |
290 | ||
291 | static struct attribute *tsl2550_attributes[] = { | |
292 | &dev_attr_power_state.attr, | |
293 | &dev_attr_operating_mode.attr, | |
294 | &dev_attr_lux1_input.attr, | |
295 | NULL | |
296 | }; | |
297 | ||
298 | static const struct attribute_group tsl2550_attr_group = { | |
299 | .attrs = tsl2550_attributes, | |
300 | }; | |
301 | ||
302 | /* | |
303 | * Initialization function | |
304 | */ | |
305 | ||
e296fb7f | 306 | static int tsl2550_init_client(struct i2c_client *client) |
a92c344d RG |
307 | { |
308 | struct tsl2550_data *data = i2c_get_clientdata(client); | |
e296fb7f | 309 | int err; |
a92c344d | 310 | |
e296fb7f JD |
311 | /* |
312 | * Probe the chip. To do so we try to power up the device and then to | |
313 | * read back the 0x03 code | |
314 | */ | |
ac780941 | 315 | err = i2c_smbus_read_byte_data(client, TSL2550_POWER_UP); |
e296fb7f JD |
316 | if (err < 0) |
317 | return err; | |
ac780941 | 318 | if (err != TSL2550_POWER_UP) |
e296fb7f JD |
319 | return -ENODEV; |
320 | data->power_state = 1; | |
321 | ||
322 | /* Set the default operating mode */ | |
323 | err = i2c_smbus_write_byte(client, | |
324 | TSL2550_MODE_RANGE[data->operating_mode]); | |
325 | if (err < 0) | |
326 | return err; | |
327 | ||
328 | return 0; | |
a92c344d RG |
329 | } |
330 | ||
331 | /* | |
332 | * I2C init/probing/exit functions | |
333 | */ | |
334 | ||
335 | static struct i2c_driver tsl2550_driver; | |
80c8ae28 | 336 | static int tsl2550_probe(struct i2c_client *client, |
d2653e92 | 337 | const struct i2c_device_id *id) |
a92c344d RG |
338 | { |
339 | struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); | |
340 | struct tsl2550_data *data; | |
341 | int *opmode, err = 0; | |
342 | ||
ac780941 JD |
343 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE |
344 | | I2C_FUNC_SMBUS_READ_BYTE_DATA)) { | |
a92c344d RG |
345 | err = -EIO; |
346 | goto exit; | |
347 | } | |
348 | ||
349 | data = kzalloc(sizeof(struct tsl2550_data), GFP_KERNEL); | |
350 | if (!data) { | |
351 | err = -ENOMEM; | |
352 | goto exit; | |
353 | } | |
354 | data->client = client; | |
355 | i2c_set_clientdata(client, data); | |
356 | ||
357 | /* Check platform data */ | |
358 | opmode = client->dev.platform_data; | |
359 | if (opmode) { | |
360 | if (*opmode < 0 || *opmode > 1) { | |
361 | dev_err(&client->dev, "invalid operating_mode (%d)\n", | |
362 | *opmode); | |
363 | err = -EINVAL; | |
364 | goto exit_kfree; | |
365 | } | |
366 | data->operating_mode = *opmode; | |
367 | } else | |
368 | data->operating_mode = 0; /* default mode is standard */ | |
369 | dev_info(&client->dev, "%s operating mode\n", | |
370 | data->operating_mode ? "extended" : "standard"); | |
371 | ||
a92c344d RG |
372 | mutex_init(&data->update_lock); |
373 | ||
374 | /* Initialize the TSL2550 chip */ | |
e296fb7f JD |
375 | err = tsl2550_init_client(client); |
376 | if (err) | |
377 | goto exit_kfree; | |
a92c344d RG |
378 | |
379 | /* Register sysfs hooks */ | |
380 | err = sysfs_create_group(&client->dev.kobj, &tsl2550_attr_group); | |
381 | if (err) | |
382 | goto exit_kfree; | |
383 | ||
384 | dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION); | |
385 | ||
386 | return 0; | |
387 | ||
388 | exit_kfree: | |
389 | kfree(data); | |
390 | exit: | |
391 | return err; | |
392 | } | |
393 | ||
486a5c28 | 394 | static int tsl2550_remove(struct i2c_client *client) |
a92c344d RG |
395 | { |
396 | sysfs_remove_group(&client->dev.kobj, &tsl2550_attr_group); | |
397 | ||
398 | /* Power down the device */ | |
399 | tsl2550_set_power_state(client, 0); | |
400 | ||
401 | kfree(i2c_get_clientdata(client)); | |
402 | ||
403 | return 0; | |
404 | } | |
405 | ||
a7761027 | 406 | #ifdef CONFIG_PM_SLEEP |
1b3e5baa | 407 | |
a7761027 | 408 | static int tsl2550_suspend(struct device *dev) |
1b3e5baa | 409 | { |
a7761027 | 410 | return tsl2550_set_power_state(to_i2c_client(dev), 0); |
1b3e5baa RG |
411 | } |
412 | ||
a7761027 | 413 | static int tsl2550_resume(struct device *dev) |
1b3e5baa | 414 | { |
a7761027 | 415 | return tsl2550_set_power_state(to_i2c_client(dev), 1); |
1b3e5baa RG |
416 | } |
417 | ||
a7761027 LPC |
418 | static SIMPLE_DEV_PM_OPS(tsl2550_pm_ops, tsl2550_suspend, tsl2550_resume); |
419 | #define TSL2550_PM_OPS (&tsl2550_pm_ops) | |
420 | ||
1b3e5baa RG |
421 | #else |
422 | ||
a7761027 | 423 | #define TSL2550_PM_OPS NULL |
1b3e5baa | 424 | |
a7761027 | 425 | #endif /* CONFIG_PM_SLEEP */ |
1b3e5baa | 426 | |
3760f736 JD |
427 | static const struct i2c_device_id tsl2550_id[] = { |
428 | { "tsl2550", 0 }, | |
429 | { } | |
430 | }; | |
431 | MODULE_DEVICE_TABLE(i2c, tsl2550_id); | |
432 | ||
d2ce8d6f JMC |
433 | static const struct of_device_id tsl2550_of_match[] = { |
434 | { .compatible = "taos,tsl2550" }, | |
435 | { } | |
436 | }; | |
437 | MODULE_DEVICE_TABLE(of, tsl2550_of_match); | |
438 | ||
a92c344d RG |
439 | static struct i2c_driver tsl2550_driver = { |
440 | .driver = { | |
441 | .name = TSL2550_DRV_NAME, | |
d2ce8d6f | 442 | .of_match_table = tsl2550_of_match, |
a7761027 | 443 | .pm = TSL2550_PM_OPS, |
a92c344d RG |
444 | }, |
445 | .probe = tsl2550_probe, | |
2d6bed9c | 446 | .remove = tsl2550_remove, |
3760f736 | 447 | .id_table = tsl2550_id, |
a92c344d RG |
448 | }; |
449 | ||
a64fe2ed | 450 | module_i2c_driver(tsl2550_driver); |
a92c344d RG |
451 | |
452 | MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>"); | |
453 | MODULE_DESCRIPTION("TSL2550 ambient light sensor driver"); | |
454 | MODULE_LICENSE("GPL"); | |
e296fb7f | 455 | MODULE_VERSION(DRIVER_VERSION); |