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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 | ||
a92c344d | 151 | /* Avoid division by 0 and count 1 cannot be greater than count 0 */ |
96f699ad MJDC |
152 | if (c1 <= c0) |
153 | if (c0) { | |
f896ee51 CIK |
154 | /* |
155 | * Calculate ratio. | |
156 | * Note: the "128" is a scaling factor | |
157 | */ | |
158 | u8 r = c1 * 128 / c0; | |
96f699ad MJDC |
159 | |
160 | /* Calculate LUX */ | |
161 | lux = ((c0 - c1) * ratio_lut[r]) / 256; | |
162 | } else | |
163 | lux = 0; | |
a92c344d | 164 | else |
ce054546 | 165 | return 0; |
a92c344d RG |
166 | |
167 | /* LUX range check */ | |
168 | return lux > TSL2550_MAX_LUX ? TSL2550_MAX_LUX : lux; | |
169 | } | |
170 | ||
171 | /* | |
172 | * SysFS support | |
173 | */ | |
174 | ||
175 | static ssize_t tsl2550_show_power_state(struct device *dev, | |
176 | struct device_attribute *attr, char *buf) | |
177 | { | |
178 | struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev)); | |
179 | ||
180 | return sprintf(buf, "%u\n", data->power_state); | |
181 | } | |
182 | ||
183 | static ssize_t tsl2550_store_power_state(struct device *dev, | |
184 | struct device_attribute *attr, const char *buf, size_t count) | |
185 | { | |
186 | struct i2c_client *client = to_i2c_client(dev); | |
187 | struct tsl2550_data *data = i2c_get_clientdata(client); | |
188 | unsigned long val = simple_strtoul(buf, NULL, 10); | |
189 | int ret; | |
190 | ||
ae8a35ae | 191 | if (val > 1) |
a92c344d RG |
192 | return -EINVAL; |
193 | ||
194 | mutex_lock(&data->update_lock); | |
195 | ret = tsl2550_set_power_state(client, val); | |
196 | mutex_unlock(&data->update_lock); | |
197 | ||
198 | if (ret < 0) | |
199 | return ret; | |
200 | ||
201 | return count; | |
202 | } | |
203 | ||
204 | static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO, | |
205 | tsl2550_show_power_state, tsl2550_store_power_state); | |
206 | ||
207 | static ssize_t tsl2550_show_operating_mode(struct device *dev, | |
208 | struct device_attribute *attr, char *buf) | |
209 | { | |
210 | struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev)); | |
211 | ||
212 | return sprintf(buf, "%u\n", data->operating_mode); | |
213 | } | |
214 | ||
215 | static ssize_t tsl2550_store_operating_mode(struct device *dev, | |
216 | struct device_attribute *attr, const char *buf, size_t count) | |
217 | { | |
218 | struct i2c_client *client = to_i2c_client(dev); | |
219 | struct tsl2550_data *data = i2c_get_clientdata(client); | |
220 | unsigned long val = simple_strtoul(buf, NULL, 10); | |
221 | int ret; | |
222 | ||
ae8a35ae | 223 | if (val > 1) |
a92c344d RG |
224 | return -EINVAL; |
225 | ||
226 | if (data->power_state == 0) | |
227 | return -EBUSY; | |
228 | ||
229 | mutex_lock(&data->update_lock); | |
230 | ret = tsl2550_set_operating_mode(client, val); | |
231 | mutex_unlock(&data->update_lock); | |
232 | ||
233 | if (ret < 0) | |
234 | return ret; | |
235 | ||
236 | return count; | |
237 | } | |
238 | ||
239 | static DEVICE_ATTR(operating_mode, S_IWUSR | S_IRUGO, | |
240 | tsl2550_show_operating_mode, tsl2550_store_operating_mode); | |
241 | ||
242 | static ssize_t __tsl2550_show_lux(struct i2c_client *client, char *buf) | |
243 | { | |
5f5bfb09 | 244 | struct tsl2550_data *data = i2c_get_clientdata(client); |
a92c344d RG |
245 | u8 ch0, ch1; |
246 | int ret; | |
247 | ||
248 | ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC0); | |
249 | if (ret < 0) | |
250 | return ret; | |
251 | ch0 = ret; | |
252 | ||
a92c344d RG |
253 | ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC1); |
254 | if (ret < 0) | |
255 | return ret; | |
256 | ch1 = ret; | |
257 | ||
258 | /* Do the job */ | |
259 | ret = tsl2550_calculate_lux(ch0, ch1); | |
260 | if (ret < 0) | |
261 | return ret; | |
5f5bfb09 MJDC |
262 | if (data->operating_mode == 1) |
263 | ret *= 5; | |
a92c344d RG |
264 | |
265 | return sprintf(buf, "%d\n", ret); | |
266 | } | |
267 | ||
268 | static ssize_t tsl2550_show_lux1_input(struct device *dev, | |
269 | struct device_attribute *attr, char *buf) | |
270 | { | |
271 | struct i2c_client *client = to_i2c_client(dev); | |
272 | struct tsl2550_data *data = i2c_get_clientdata(client); | |
273 | int ret; | |
274 | ||
275 | /* No LUX data if not operational */ | |
276 | if (!data->power_state) | |
277 | return -EBUSY; | |
278 | ||
279 | mutex_lock(&data->update_lock); | |
280 | ret = __tsl2550_show_lux(client, buf); | |
281 | mutex_unlock(&data->update_lock); | |
282 | ||
283 | return ret; | |
284 | } | |
285 | ||
286 | static DEVICE_ATTR(lux1_input, S_IRUGO, | |
287 | tsl2550_show_lux1_input, NULL); | |
288 | ||
289 | static struct attribute *tsl2550_attributes[] = { | |
290 | &dev_attr_power_state.attr, | |
291 | &dev_attr_operating_mode.attr, | |
292 | &dev_attr_lux1_input.attr, | |
293 | NULL | |
294 | }; | |
295 | ||
296 | static const struct attribute_group tsl2550_attr_group = { | |
297 | .attrs = tsl2550_attributes, | |
298 | }; | |
299 | ||
300 | /* | |
301 | * Initialization function | |
302 | */ | |
303 | ||
e296fb7f | 304 | static int tsl2550_init_client(struct i2c_client *client) |
a92c344d RG |
305 | { |
306 | struct tsl2550_data *data = i2c_get_clientdata(client); | |
e296fb7f | 307 | int err; |
a92c344d | 308 | |
e296fb7f JD |
309 | /* |
310 | * Probe the chip. To do so we try to power up the device and then to | |
311 | * read back the 0x03 code | |
312 | */ | |
ac780941 | 313 | err = i2c_smbus_read_byte_data(client, TSL2550_POWER_UP); |
e296fb7f JD |
314 | if (err < 0) |
315 | return err; | |
ac780941 | 316 | if (err != TSL2550_POWER_UP) |
e296fb7f JD |
317 | return -ENODEV; |
318 | data->power_state = 1; | |
319 | ||
320 | /* Set the default operating mode */ | |
321 | err = i2c_smbus_write_byte(client, | |
322 | TSL2550_MODE_RANGE[data->operating_mode]); | |
323 | if (err < 0) | |
324 | return err; | |
325 | ||
326 | return 0; | |
a92c344d RG |
327 | } |
328 | ||
329 | /* | |
330 | * I2C init/probing/exit functions | |
331 | */ | |
332 | ||
333 | static struct i2c_driver tsl2550_driver; | |
80c8ae28 | 334 | static int tsl2550_probe(struct i2c_client *client, |
d2653e92 | 335 | const struct i2c_device_id *id) |
a92c344d | 336 | { |
3cc2decc | 337 | struct i2c_adapter *adapter = client->adapter; |
a92c344d RG |
338 | struct tsl2550_data *data; |
339 | int *opmode, err = 0; | |
340 | ||
ac780941 JD |
341 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE |
342 | | I2C_FUNC_SMBUS_READ_BYTE_DATA)) { | |
a92c344d RG |
343 | err = -EIO; |
344 | goto exit; | |
345 | } | |
346 | ||
347 | data = kzalloc(sizeof(struct tsl2550_data), GFP_KERNEL); | |
348 | if (!data) { | |
349 | err = -ENOMEM; | |
350 | goto exit; | |
351 | } | |
352 | data->client = client; | |
353 | i2c_set_clientdata(client, data); | |
354 | ||
355 | /* Check platform data */ | |
356 | opmode = client->dev.platform_data; | |
357 | if (opmode) { | |
358 | if (*opmode < 0 || *opmode > 1) { | |
359 | dev_err(&client->dev, "invalid operating_mode (%d)\n", | |
360 | *opmode); | |
361 | err = -EINVAL; | |
362 | goto exit_kfree; | |
363 | } | |
364 | data->operating_mode = *opmode; | |
365 | } else | |
366 | data->operating_mode = 0; /* default mode is standard */ | |
367 | dev_info(&client->dev, "%s operating mode\n", | |
368 | data->operating_mode ? "extended" : "standard"); | |
369 | ||
a92c344d RG |
370 | mutex_init(&data->update_lock); |
371 | ||
372 | /* Initialize the TSL2550 chip */ | |
e296fb7f JD |
373 | err = tsl2550_init_client(client); |
374 | if (err) | |
375 | goto exit_kfree; | |
a92c344d RG |
376 | |
377 | /* Register sysfs hooks */ | |
378 | err = sysfs_create_group(&client->dev.kobj, &tsl2550_attr_group); | |
379 | if (err) | |
380 | goto exit_kfree; | |
381 | ||
382 | dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION); | |
383 | ||
384 | return 0; | |
385 | ||
386 | exit_kfree: | |
387 | kfree(data); | |
388 | exit: | |
389 | return err; | |
390 | } | |
391 | ||
486a5c28 | 392 | static int tsl2550_remove(struct i2c_client *client) |
a92c344d RG |
393 | { |
394 | sysfs_remove_group(&client->dev.kobj, &tsl2550_attr_group); | |
395 | ||
396 | /* Power down the device */ | |
397 | tsl2550_set_power_state(client, 0); | |
398 | ||
399 | kfree(i2c_get_clientdata(client)); | |
400 | ||
401 | return 0; | |
402 | } | |
403 | ||
a7761027 | 404 | #ifdef CONFIG_PM_SLEEP |
1b3e5baa | 405 | |
a7761027 | 406 | static int tsl2550_suspend(struct device *dev) |
1b3e5baa | 407 | { |
a7761027 | 408 | return tsl2550_set_power_state(to_i2c_client(dev), 0); |
1b3e5baa RG |
409 | } |
410 | ||
a7761027 | 411 | static int tsl2550_resume(struct device *dev) |
1b3e5baa | 412 | { |
a7761027 | 413 | return tsl2550_set_power_state(to_i2c_client(dev), 1); |
1b3e5baa RG |
414 | } |
415 | ||
a7761027 LPC |
416 | static SIMPLE_DEV_PM_OPS(tsl2550_pm_ops, tsl2550_suspend, tsl2550_resume); |
417 | #define TSL2550_PM_OPS (&tsl2550_pm_ops) | |
418 | ||
1b3e5baa RG |
419 | #else |
420 | ||
a7761027 | 421 | #define TSL2550_PM_OPS NULL |
1b3e5baa | 422 | |
a7761027 | 423 | #endif /* CONFIG_PM_SLEEP */ |
1b3e5baa | 424 | |
3760f736 JD |
425 | static const struct i2c_device_id tsl2550_id[] = { |
426 | { "tsl2550", 0 }, | |
427 | { } | |
428 | }; | |
429 | MODULE_DEVICE_TABLE(i2c, tsl2550_id); | |
430 | ||
d2ce8d6f JMC |
431 | static const struct of_device_id tsl2550_of_match[] = { |
432 | { .compatible = "taos,tsl2550" }, | |
433 | { } | |
434 | }; | |
435 | MODULE_DEVICE_TABLE(of, tsl2550_of_match); | |
436 | ||
a92c344d RG |
437 | static struct i2c_driver tsl2550_driver = { |
438 | .driver = { | |
439 | .name = TSL2550_DRV_NAME, | |
d2ce8d6f | 440 | .of_match_table = tsl2550_of_match, |
a7761027 | 441 | .pm = TSL2550_PM_OPS, |
a92c344d RG |
442 | }, |
443 | .probe = tsl2550_probe, | |
2d6bed9c | 444 | .remove = tsl2550_remove, |
3760f736 | 445 | .id_table = tsl2550_id, |
a92c344d RG |
446 | }; |
447 | ||
a64fe2ed | 448 | module_i2c_driver(tsl2550_driver); |
a92c344d RG |
449 | |
450 | MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>"); | |
451 | MODULE_DESCRIPTION("TSL2550 ambient light sensor driver"); | |
452 | MODULE_LICENSE("GPL"); | |
e296fb7f | 453 | MODULE_VERSION(DRIVER_VERSION); |