1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * zopt2201.c - Support for IDT ZOPT2201 ambient light and UV B sensor
4 *
5 * Copyright 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net>
6 *
7 * Datasheet: https://www.idt.com/document/dst/zopt2201-datasheet
8 * 7-bit I2C slave addresses 0x53 (default) or 0x52 (programmed)
9 *
10 * TODO: interrupt support, ALS/UVB raw mode
11 */
12
13 #include <linux/module.h>
14 #include <linux/i2c.h>
15 #include <linux/mutex.h>
16 #include <linux/err.h>
17 #include <linux/delay.h>
18
19 #include <linux/iio/iio.h>
20 #include <linux/iio/sysfs.h>
21
22 #include <linux/unaligned.h>
23
24 #define ZOPT2201_DRV_NAME "zopt2201"
25
26 /* Registers */
27 #define ZOPT2201_MAIN_CTRL 0x00
28 #define ZOPT2201_LS_MEAS_RATE 0x04
29 #define ZOPT2201_LS_GAIN 0x05
30 #define ZOPT2201_PART_ID 0x06
31 #define ZOPT2201_MAIN_STATUS 0x07
32 #define ZOPT2201_ALS_DATA 0x0d /* LSB first, 13 to 20 bits */
33 #define ZOPT2201_UVB_DATA 0x10 /* LSB first, 13 to 20 bits */
34 #define ZOPT2201_UV_COMP_DATA 0x13 /* LSB first, 13 to 20 bits */
35 #define ZOPT2201_COMP_DATA 0x16 /* LSB first, 13 to 20 bits */
36 #define ZOPT2201_INT_CFG 0x19
37 #define ZOPT2201_INT_PST 0x1a
38
39 #define ZOPT2201_MAIN_CTRL_LS_MODE BIT(3) /* 0 .. ALS, 1 .. UV B */
40 #define ZOPT2201_MAIN_CTRL_LS_EN BIT(1)
41
42 /* Values for ZOPT2201_LS_MEAS_RATE resolution / bit width */
43 #define ZOPT2201_MEAS_RES_20BIT 0 /* takes 400 ms */
44 #define ZOPT2201_MEAS_RES_19BIT 1 /* takes 200 ms */
45 #define ZOPT2201_MEAS_RES_18BIT 2 /* takes 100 ms, default */
46 #define ZOPT2201_MEAS_RES_17BIT 3 /* takes 50 ms */
47 #define ZOPT2201_MEAS_RES_16BIT 4 /* takes 25 ms */
48 #define ZOPT2201_MEAS_RES_13BIT 5 /* takes 3.125 ms */
49 #define ZOPT2201_MEAS_RES_SHIFT 4
50
51 /* Values for ZOPT2201_LS_MEAS_RATE measurement rate */
52 #define ZOPT2201_MEAS_FREQ_25MS 0
53 #define ZOPT2201_MEAS_FREQ_50MS 1
54 #define ZOPT2201_MEAS_FREQ_100MS 2 /* default */
55 #define ZOPT2201_MEAS_FREQ_200MS 3
56 #define ZOPT2201_MEAS_FREQ_500MS 4
57 #define ZOPT2201_MEAS_FREQ_1000MS 5
58 #define ZOPT2201_MEAS_FREQ_2000MS 6
59
60 /* Values for ZOPT2201_LS_GAIN */
61 #define ZOPT2201_LS_GAIN_1 0
62 #define ZOPT2201_LS_GAIN_3 1
63 #define ZOPT2201_LS_GAIN_6 2
64 #define ZOPT2201_LS_GAIN_9 3
65 #define ZOPT2201_LS_GAIN_18 4
66
67 /* Values for ZOPT2201_MAIN_STATUS */
68 #define ZOPT2201_MAIN_STATUS_POWERON BIT(5)
69 #define ZOPT2201_MAIN_STATUS_INT BIT(4)
70 #define ZOPT2201_MAIN_STATUS_DRDY BIT(3)
71
72 #define ZOPT2201_PART_NUMBER 0xb2
73
74 struct zopt2201_data {
75 struct i2c_client *client;
76 struct mutex lock;
77 u8 gain;
78 u8 res;
79 u8 rate;
80 };
81
82 static const struct {
83 unsigned int gain; /* gain factor */
84 unsigned int scale; /* micro lux per count */
85 } zopt2201_gain_als[] = {
86 { 1, 19200000 },
87 { 3, 6400000 },
88 { 6, 3200000 },
89 { 9, 2133333 },
90 { 18, 1066666 },
91 };
92
93 static const struct {
94 unsigned int gain; /* gain factor */
95 unsigned int scale; /* micro W/m2 per count */
96 } zopt2201_gain_uvb[] = {
97 { 1, 460800 },
98 { 3, 153600 },
99 { 6, 76800 },
100 { 9, 51200 },
101 { 18, 25600 },
102 };
103
104 static const struct {
105 unsigned int bits; /* sensor resolution in bits */
106 unsigned long us; /* measurement time in micro seconds */
107 } zopt2201_resolution[] = {
108 { 20, 400000 },
109 { 19, 200000 },
110 { 18, 100000 },
111 { 17, 50000 },
112 { 16, 25000 },
113 { 13, 3125 },
114 };
115
116 struct zopt2201_scale {
117 unsigned int scale, uscale; /* scale factor as integer + micro */
118 u8 gain; /* gain register value */
119 u8 res; /* resolution register value */
120 };
121
122 static struct zopt2201_scale zopt2201_scale_als[] = {
123 { 19, 200000, 0, 5 },
124 { 6, 400000, 1, 5 },
125 { 3, 200000, 2, 5 },
126 { 2, 400000, 0, 4 },
127 { 2, 133333, 3, 5 },
128 { 1, 200000, 0, 3 },
129 { 1, 66666, 4, 5 },
130 { 0, 800000, 1, 4 },
131 { 0, 600000, 0, 2 },
132 { 0, 400000, 2, 4 },
133 { 0, 300000, 0, 1 },
134 { 0, 266666, 3, 4 },
135 { 0, 200000, 2, 3 },
136 { 0, 150000, 0, 0 },
137 { 0, 133333, 4, 4 },
138 { 0, 100000, 2, 2 },
139 { 0, 66666, 4, 3 },
140 { 0, 50000, 2, 1 },
141 { 0, 33333, 4, 2 },
142 { 0, 25000, 2, 0 },
143 { 0, 16666, 4, 1 },
144 { 0, 8333, 4, 0 },
145 };
146
147 static struct zopt2201_scale zopt2201_scale_uvb[] = {
148 { 0, 460800, 0, 5 },
149 { 0, 153600, 1, 5 },
150 { 0, 76800, 2, 5 },
151 { 0, 57600, 0, 4 },
152 { 0, 51200, 3, 5 },
153 { 0, 28800, 0, 3 },
154 { 0, 25600, 4, 5 },
155 { 0, 19200, 1, 4 },
156 { 0, 14400, 0, 2 },
157 { 0, 9600, 2, 4 },
158 { 0, 7200, 0, 1 },
159 { 0, 6400, 3, 4 },
160 { 0, 4800, 2, 3 },
161 { 0, 3600, 0, 0 },
162 { 0, 3200, 4, 4 },
163 { 0, 2400, 2, 2 },
164 { 0, 1600, 4, 3 },
165 { 0, 1200, 2, 1 },
166 { 0, 800, 4, 2 },
167 { 0, 600, 2, 0 },
168 { 0, 400, 4, 1 },
169 { 0, 200, 4, 0 },
170 };
171
zopt2201_enable_mode(struct zopt2201_data * data,bool uvb_mode)172 static int zopt2201_enable_mode(struct zopt2201_data *data, bool uvb_mode)
173 {
174 u8 out = ZOPT2201_MAIN_CTRL_LS_EN;
175
176 if (uvb_mode)
177 out |= ZOPT2201_MAIN_CTRL_LS_MODE;
178
179 return i2c_smbus_write_byte_data(data->client, ZOPT2201_MAIN_CTRL, out);
180 }
181
zopt2201_read(struct zopt2201_data * data,u8 reg)182 static int zopt2201_read(struct zopt2201_data *data, u8 reg)
183 {
184 struct i2c_client *client = data->client;
185 int tries = 10;
186 u8 buf[3];
187 int ret;
188
189 mutex_lock(&data->lock);
190 ret = zopt2201_enable_mode(data, reg == ZOPT2201_UVB_DATA);
191 if (ret < 0)
192 goto fail;
193
194 while (tries--) {
195 unsigned long t = zopt2201_resolution[data->res].us;
196
197 if (t <= 20000)
198 usleep_range(t, t + 1000);
199 else
200 msleep(t / 1000);
201 ret = i2c_smbus_read_byte_data(client, ZOPT2201_MAIN_STATUS);
202 if (ret < 0)
203 goto fail;
204 if (ret & ZOPT2201_MAIN_STATUS_DRDY)
205 break;
206 }
207
208 if (tries < 0) {
209 ret = -ETIMEDOUT;
210 goto fail;
211 }
212
213 ret = i2c_smbus_read_i2c_block_data(client, reg, sizeof(buf), buf);
214 if (ret < 0)
215 goto fail;
216
217 ret = i2c_smbus_write_byte_data(client, ZOPT2201_MAIN_CTRL, 0x00);
218 if (ret < 0)
219 goto fail;
220 mutex_unlock(&data->lock);
221
222 return get_unaligned_le24(&buf[0]);
223
224 fail:
225 mutex_unlock(&data->lock);
226 return ret;
227 }
228
229 static const struct iio_chan_spec zopt2201_channels[] = {
230 {
231 .type = IIO_LIGHT,
232 .address = ZOPT2201_ALS_DATA,
233 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
234 BIT(IIO_CHAN_INFO_SCALE),
235 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
236 },
237 {
238 .type = IIO_INTENSITY,
239 .modified = 1,
240 .channel2 = IIO_MOD_LIGHT_UV,
241 .address = ZOPT2201_UVB_DATA,
242 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
243 BIT(IIO_CHAN_INFO_SCALE),
244 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
245 },
246 {
247 .type = IIO_UVINDEX,
248 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
249 },
250 };
251
zopt2201_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)252 static int zopt2201_read_raw(struct iio_dev *indio_dev,
253 struct iio_chan_spec const *chan,
254 int *val, int *val2, long mask)
255 {
256 struct zopt2201_data *data = iio_priv(indio_dev);
257 u64 tmp;
258 int ret;
259
260 switch (mask) {
261 case IIO_CHAN_INFO_RAW:
262 ret = zopt2201_read(data, chan->address);
263 if (ret < 0)
264 return ret;
265 *val = ret;
266 return IIO_VAL_INT;
267 case IIO_CHAN_INFO_PROCESSED:
268 ret = zopt2201_read(data, ZOPT2201_UVB_DATA);
269 if (ret < 0)
270 return ret;
271 *val = ret * 18 *
272 (1 << (20 - zopt2201_resolution[data->res].bits)) /
273 zopt2201_gain_uvb[data->gain].gain;
274 return IIO_VAL_INT;
275 case IIO_CHAN_INFO_SCALE:
276 switch (chan->address) {
277 case ZOPT2201_ALS_DATA:
278 *val = zopt2201_gain_als[data->gain].scale;
279 break;
280 case ZOPT2201_UVB_DATA:
281 *val = zopt2201_gain_uvb[data->gain].scale;
282 break;
283 default:
284 return -EINVAL;
285 }
286
287 *val2 = 1000000;
288 *val2 *= (1 << (zopt2201_resolution[data->res].bits - 13));
289 tmp = div_s64(*val * 1000000ULL, *val2);
290 *val = div_s64_rem(tmp, 1000000, val2);
291
292 return IIO_VAL_INT_PLUS_MICRO;
293 case IIO_CHAN_INFO_INT_TIME:
294 *val = 0;
295 *val2 = zopt2201_resolution[data->res].us;
296 return IIO_VAL_INT_PLUS_MICRO;
297 default:
298 return -EINVAL;
299 }
300 }
301
zopt2201_set_resolution(struct zopt2201_data * data,u8 res)302 static int zopt2201_set_resolution(struct zopt2201_data *data, u8 res)
303 {
304 int ret;
305
306 ret = i2c_smbus_write_byte_data(data->client, ZOPT2201_LS_MEAS_RATE,
307 (res << ZOPT2201_MEAS_RES_SHIFT) |
308 data->rate);
309 if (ret < 0)
310 return ret;
311
312 data->res = res;
313
314 return 0;
315 }
316
zopt2201_write_resolution(struct zopt2201_data * data,int val,int val2)317 static int zopt2201_write_resolution(struct zopt2201_data *data,
318 int val, int val2)
319 {
320 int i, ret;
321
322 if (val != 0)
323 return -EINVAL;
324
325 for (i = 0; i < ARRAY_SIZE(zopt2201_resolution); i++)
326 if (val2 == zopt2201_resolution[i].us) {
327 mutex_lock(&data->lock);
328 ret = zopt2201_set_resolution(data, i);
329 mutex_unlock(&data->lock);
330 return ret;
331 }
332
333 return -EINVAL;
334 }
335
zopt2201_set_gain(struct zopt2201_data * data,u8 gain)336 static int zopt2201_set_gain(struct zopt2201_data *data, u8 gain)
337 {
338 int ret;
339
340 ret = i2c_smbus_write_byte_data(data->client, ZOPT2201_LS_GAIN, gain);
341 if (ret < 0)
342 return ret;
343
344 data->gain = gain;
345
346 return 0;
347 }
348
zopt2201_write_scale_by_idx(struct zopt2201_data * data,int idx,struct zopt2201_scale * zopt2201_scale_array)349 static int zopt2201_write_scale_by_idx(struct zopt2201_data *data, int idx,
350 struct zopt2201_scale *zopt2201_scale_array)
351 {
352 int ret;
353
354 mutex_lock(&data->lock);
355 ret = zopt2201_set_resolution(data, zopt2201_scale_array[idx].res);
356 if (ret < 0)
357 goto unlock;
358
359 ret = zopt2201_set_gain(data, zopt2201_scale_array[idx].gain);
360
361 unlock:
362 mutex_unlock(&data->lock);
363 return ret;
364 }
365
zopt2201_write_scale_als(struct zopt2201_data * data,int val,int val2)366 static int zopt2201_write_scale_als(struct zopt2201_data *data,
367 int val, int val2)
368 {
369 int i;
370
371 for (i = 0; i < ARRAY_SIZE(zopt2201_scale_als); i++)
372 if (val == zopt2201_scale_als[i].scale &&
373 val2 == zopt2201_scale_als[i].uscale)
374 return zopt2201_write_scale_by_idx(data, i, zopt2201_scale_als);
375
376 return -EINVAL;
377 }
378
zopt2201_write_scale_uvb(struct zopt2201_data * data,int val,int val2)379 static int zopt2201_write_scale_uvb(struct zopt2201_data *data,
380 int val, int val2)
381 {
382 int i;
383
384 for (i = 0; i < ARRAY_SIZE(zopt2201_scale_uvb); i++)
385 if (val == zopt2201_scale_uvb[i].scale &&
386 val2 == zopt2201_scale_uvb[i].uscale)
387 return zopt2201_write_scale_by_idx(data, i, zopt2201_scale_uvb);
388
389 return -EINVAL;
390 }
391
zopt2201_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)392 static int zopt2201_write_raw(struct iio_dev *indio_dev,
393 struct iio_chan_spec const *chan,
394 int val, int val2, long mask)
395 {
396 struct zopt2201_data *data = iio_priv(indio_dev);
397
398 switch (mask) {
399 case IIO_CHAN_INFO_INT_TIME:
400 return zopt2201_write_resolution(data, val, val2);
401 case IIO_CHAN_INFO_SCALE:
402 switch (chan->address) {
403 case ZOPT2201_ALS_DATA:
404 return zopt2201_write_scale_als(data, val, val2);
405 case ZOPT2201_UVB_DATA:
406 return zopt2201_write_scale_uvb(data, val, val2);
407 default:
408 return -EINVAL;
409 }
410 }
411
412 return -EINVAL;
413 }
414
zopt2201_show_int_time_available(struct device * dev,struct device_attribute * attr,char * buf)415 static ssize_t zopt2201_show_int_time_available(struct device *dev,
416 struct device_attribute *attr,
417 char *buf)
418 {
419 size_t len = 0;
420 int i;
421
422 for (i = 0; i < ARRAY_SIZE(zopt2201_resolution); i++)
423 len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06lu ",
424 zopt2201_resolution[i].us);
425 buf[len - 1] = '\n';
426
427 return len;
428 }
429
430 static IIO_DEV_ATTR_INT_TIME_AVAIL(zopt2201_show_int_time_available);
431
zopt2201_show_als_scale_avail(struct device * dev,struct device_attribute * attr,char * buf)432 static ssize_t zopt2201_show_als_scale_avail(struct device *dev,
433 struct device_attribute *attr,
434 char *buf)
435 {
436 ssize_t len = 0;
437 int i;
438
439 for (i = 0; i < ARRAY_SIZE(zopt2201_scale_als); i++)
440 len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06u ",
441 zopt2201_scale_als[i].scale,
442 zopt2201_scale_als[i].uscale);
443 buf[len - 1] = '\n';
444
445 return len;
446 }
447
zopt2201_show_uvb_scale_avail(struct device * dev,struct device_attribute * attr,char * buf)448 static ssize_t zopt2201_show_uvb_scale_avail(struct device *dev,
449 struct device_attribute *attr,
450 char *buf)
451 {
452 ssize_t len = 0;
453 int i;
454
455 for (i = 0; i < ARRAY_SIZE(zopt2201_scale_uvb); i++)
456 len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06u ",
457 zopt2201_scale_uvb[i].scale,
458 zopt2201_scale_uvb[i].uscale);
459 buf[len - 1] = '\n';
460
461 return len;
462 }
463
464 static IIO_DEVICE_ATTR(in_illuminance_scale_available, 0444,
465 zopt2201_show_als_scale_avail, NULL, 0);
466 static IIO_DEVICE_ATTR(in_intensity_uv_scale_available, 0444,
467 zopt2201_show_uvb_scale_avail, NULL, 0);
468
469 static struct attribute *zopt2201_attributes[] = {
470 &iio_dev_attr_integration_time_available.dev_attr.attr,
471 &iio_dev_attr_in_illuminance_scale_available.dev_attr.attr,
472 &iio_dev_attr_in_intensity_uv_scale_available.dev_attr.attr,
473 NULL
474 };
475
476 static const struct attribute_group zopt2201_attribute_group = {
477 .attrs = zopt2201_attributes,
478 };
479
480 static const struct iio_info zopt2201_info = {
481 .read_raw = zopt2201_read_raw,
482 .write_raw = zopt2201_write_raw,
483 .attrs = &zopt2201_attribute_group,
484 };
485
zopt2201_probe(struct i2c_client * client)486 static int zopt2201_probe(struct i2c_client *client)
487 {
488 struct zopt2201_data *data;
489 struct iio_dev *indio_dev;
490 int ret;
491
492 if (!i2c_check_functionality(client->adapter,
493 I2C_FUNC_SMBUS_READ_I2C_BLOCK))
494 return -EOPNOTSUPP;
495
496 ret = i2c_smbus_read_byte_data(client, ZOPT2201_PART_ID);
497 if (ret < 0)
498 return ret;
499 if (ret != ZOPT2201_PART_NUMBER)
500 return -ENODEV;
501
502 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
503 if (!indio_dev)
504 return -ENOMEM;
505
506 data = iio_priv(indio_dev);
507 i2c_set_clientdata(client, indio_dev);
508 data->client = client;
509 mutex_init(&data->lock);
510
511 indio_dev->info = &zopt2201_info;
512 indio_dev->channels = zopt2201_channels;
513 indio_dev->num_channels = ARRAY_SIZE(zopt2201_channels);
514 indio_dev->name = ZOPT2201_DRV_NAME;
515 indio_dev->modes = INDIO_DIRECT_MODE;
516
517 data->rate = ZOPT2201_MEAS_FREQ_100MS;
518 ret = zopt2201_set_resolution(data, ZOPT2201_MEAS_RES_18BIT);
519 if (ret < 0)
520 return ret;
521
522 ret = zopt2201_set_gain(data, ZOPT2201_LS_GAIN_3);
523 if (ret < 0)
524 return ret;
525
526 return devm_iio_device_register(&client->dev, indio_dev);
527 }
528
529 static const struct i2c_device_id zopt2201_id[] = {
530 { "zopt2201" },
531 { }
532 };
533 MODULE_DEVICE_TABLE(i2c, zopt2201_id);
534
535 static struct i2c_driver zopt2201_driver = {
536 .driver = {
537 .name = ZOPT2201_DRV_NAME,
538 },
539 .probe = zopt2201_probe,
540 .id_table = zopt2201_id,
541 };
542
543 module_i2c_driver(zopt2201_driver);
544
545 MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>");
546 MODULE_DESCRIPTION("IDT ZOPT2201 ambient light and UV B sensor driver");
547 MODULE_LICENSE("GPL");
548