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 static const struct {
117 unsigned int scale, uscale; /* scale factor as integer + micro */
118 u8 gain; /* gain register value */
119 u8 res; /* resolution register value */
120 } zopt2201_scale_als[] = {
121 { 19, 200000, 0, 5 },
122 { 6, 400000, 1, 5 },
123 { 3, 200000, 2, 5 },
124 { 2, 400000, 0, 4 },
125 { 2, 133333, 3, 5 },
126 { 1, 200000, 0, 3 },
127 { 1, 66666, 4, 5 },
128 { 0, 800000, 1, 4 },
129 { 0, 600000, 0, 2 },
130 { 0, 400000, 2, 4 },
131 { 0, 300000, 0, 1 },
132 { 0, 266666, 3, 4 },
133 { 0, 200000, 2, 3 },
134 { 0, 150000, 0, 0 },
135 { 0, 133333, 4, 4 },
136 { 0, 100000, 2, 2 },
137 { 0, 66666, 4, 3 },
138 { 0, 50000, 2, 1 },
139 { 0, 33333, 4, 2 },
140 { 0, 25000, 2, 0 },
141 { 0, 16666, 4, 1 },
142 { 0, 8333, 4, 0 },
143 };
144
145 static const struct {
146 unsigned int scale, uscale; /* scale factor as integer + micro */
147 u8 gain; /* gain register value */
148 u8 res; /* resolution register value */
149 } zopt2201_scale_uvb[] = {
150 { 0, 460800, 0, 5 },
151 { 0, 153600, 1, 5 },
152 { 0, 76800, 2, 5 },
153 { 0, 57600, 0, 4 },
154 { 0, 51200, 3, 5 },
155 { 0, 28800, 0, 3 },
156 { 0, 25600, 4, 5 },
157 { 0, 19200, 1, 4 },
158 { 0, 14400, 0, 2 },
159 { 0, 9600, 2, 4 },
160 { 0, 7200, 0, 1 },
161 { 0, 6400, 3, 4 },
162 { 0, 4800, 2, 3 },
163 { 0, 3600, 0, 0 },
164 { 0, 3200, 4, 4 },
165 { 0, 2400, 2, 2 },
166 { 0, 1600, 4, 3 },
167 { 0, 1200, 2, 1 },
168 { 0, 800, 4, 2 },
169 { 0, 600, 2, 0 },
170 { 0, 400, 4, 1 },
171 { 0, 200, 4, 0 },
172 };
173
zopt2201_enable_mode(struct zopt2201_data * data,bool uvb_mode)174 static int zopt2201_enable_mode(struct zopt2201_data *data, bool uvb_mode)
175 {
176 u8 out = ZOPT2201_MAIN_CTRL_LS_EN;
177
178 if (uvb_mode)
179 out |= ZOPT2201_MAIN_CTRL_LS_MODE;
180
181 return i2c_smbus_write_byte_data(data->client, ZOPT2201_MAIN_CTRL, out);
182 }
183
zopt2201_read(struct zopt2201_data * data,u8 reg)184 static int zopt2201_read(struct zopt2201_data *data, u8 reg)
185 {
186 struct i2c_client *client = data->client;
187 int tries = 10;
188 u8 buf[3];
189 int ret;
190
191 mutex_lock(&data->lock);
192 ret = zopt2201_enable_mode(data, reg == ZOPT2201_UVB_DATA);
193 if (ret < 0)
194 goto fail;
195
196 while (tries--) {
197 unsigned long t = zopt2201_resolution[data->res].us;
198
199 if (t <= 20000)
200 usleep_range(t, t + 1000);
201 else
202 msleep(t / 1000);
203 ret = i2c_smbus_read_byte_data(client, ZOPT2201_MAIN_STATUS);
204 if (ret < 0)
205 goto fail;
206 if (ret & ZOPT2201_MAIN_STATUS_DRDY)
207 break;
208 }
209
210 if (tries < 0) {
211 ret = -ETIMEDOUT;
212 goto fail;
213 }
214
215 ret = i2c_smbus_read_i2c_block_data(client, reg, sizeof(buf), buf);
216 if (ret < 0)
217 goto fail;
218
219 ret = i2c_smbus_write_byte_data(client, ZOPT2201_MAIN_CTRL, 0x00);
220 if (ret < 0)
221 goto fail;
222 mutex_unlock(&data->lock);
223
224 return get_unaligned_le24(&buf[0]);
225
226 fail:
227 mutex_unlock(&data->lock);
228 return ret;
229 }
230
231 static const struct iio_chan_spec zopt2201_channels[] = {
232 {
233 .type = IIO_LIGHT,
234 .address = ZOPT2201_ALS_DATA,
235 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
236 BIT(IIO_CHAN_INFO_SCALE),
237 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
238 },
239 {
240 .type = IIO_INTENSITY,
241 .modified = 1,
242 .channel2 = IIO_MOD_LIGHT_UV,
243 .address = ZOPT2201_UVB_DATA,
244 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
245 BIT(IIO_CHAN_INFO_SCALE),
246 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
247 },
248 {
249 .type = IIO_UVINDEX,
250 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
251 },
252 };
253
zopt2201_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)254 static int zopt2201_read_raw(struct iio_dev *indio_dev,
255 struct iio_chan_spec const *chan,
256 int *val, int *val2, long mask)
257 {
258 struct zopt2201_data *data = iio_priv(indio_dev);
259 u64 tmp;
260 int ret;
261
262 switch (mask) {
263 case IIO_CHAN_INFO_RAW:
264 ret = zopt2201_read(data, chan->address);
265 if (ret < 0)
266 return ret;
267 *val = ret;
268 return IIO_VAL_INT;
269 case IIO_CHAN_INFO_PROCESSED:
270 ret = zopt2201_read(data, ZOPT2201_UVB_DATA);
271 if (ret < 0)
272 return ret;
273 *val = ret * 18 *
274 (1 << (20 - zopt2201_resolution[data->res].bits)) /
275 zopt2201_gain_uvb[data->gain].gain;
276 return IIO_VAL_INT;
277 case IIO_CHAN_INFO_SCALE:
278 switch (chan->address) {
279 case ZOPT2201_ALS_DATA:
280 *val = zopt2201_gain_als[data->gain].scale;
281 break;
282 case ZOPT2201_UVB_DATA:
283 *val = zopt2201_gain_uvb[data->gain].scale;
284 break;
285 default:
286 return -EINVAL;
287 }
288
289 *val2 = 1000000;
290 *val2 *= (1 << (zopt2201_resolution[data->res].bits - 13));
291 tmp = div_s64(*val * 1000000ULL, *val2);
292 *val = div_s64_rem(tmp, 1000000, val2);
293
294 return IIO_VAL_INT_PLUS_MICRO;
295 case IIO_CHAN_INFO_INT_TIME:
296 *val = 0;
297 *val2 = zopt2201_resolution[data->res].us;
298 return IIO_VAL_INT_PLUS_MICRO;
299 default:
300 return -EINVAL;
301 }
302 }
303
zopt2201_set_resolution(struct zopt2201_data * data,u8 res)304 static int zopt2201_set_resolution(struct zopt2201_data *data, u8 res)
305 {
306 int ret;
307
308 ret = i2c_smbus_write_byte_data(data->client, ZOPT2201_LS_MEAS_RATE,
309 (res << ZOPT2201_MEAS_RES_SHIFT) |
310 data->rate);
311 if (ret < 0)
312 return ret;
313
314 data->res = res;
315
316 return 0;
317 }
318
zopt2201_write_resolution(struct zopt2201_data * data,int val,int val2)319 static int zopt2201_write_resolution(struct zopt2201_data *data,
320 int val, int val2)
321 {
322 int i, ret;
323
324 if (val != 0)
325 return -EINVAL;
326
327 for (i = 0; i < ARRAY_SIZE(zopt2201_resolution); i++)
328 if (val2 == zopt2201_resolution[i].us) {
329 mutex_lock(&data->lock);
330 ret = zopt2201_set_resolution(data, i);
331 mutex_unlock(&data->lock);
332 return ret;
333 }
334
335 return -EINVAL;
336 }
337
zopt2201_set_gain(struct zopt2201_data * data,u8 gain)338 static int zopt2201_set_gain(struct zopt2201_data *data, u8 gain)
339 {
340 int ret;
341
342 ret = i2c_smbus_write_byte_data(data->client, ZOPT2201_LS_GAIN, gain);
343 if (ret < 0)
344 return ret;
345
346 data->gain = gain;
347
348 return 0;
349 }
350
zopt2201_write_scale_als_by_idx(struct zopt2201_data * data,int idx)351 static int zopt2201_write_scale_als_by_idx(struct zopt2201_data *data, int idx)
352 {
353 int ret;
354
355 mutex_lock(&data->lock);
356 ret = zopt2201_set_resolution(data, zopt2201_scale_als[idx].res);
357 if (ret < 0)
358 goto unlock;
359
360 ret = zopt2201_set_gain(data, zopt2201_scale_als[idx].gain);
361
362 unlock:
363 mutex_unlock(&data->lock);
364 return ret;
365 }
366
zopt2201_write_scale_als(struct zopt2201_data * data,int val,int val2)367 static int zopt2201_write_scale_als(struct zopt2201_data *data,
368 int val, int val2)
369 {
370 int i;
371
372 for (i = 0; i < ARRAY_SIZE(zopt2201_scale_als); i++)
373 if (val == zopt2201_scale_als[i].scale &&
374 val2 == zopt2201_scale_als[i].uscale) {
375 return zopt2201_write_scale_als_by_idx(data, i);
376 }
377
378 return -EINVAL;
379 }
380
zopt2201_write_scale_uvb_by_idx(struct zopt2201_data * data,int idx)381 static int zopt2201_write_scale_uvb_by_idx(struct zopt2201_data *data, int idx)
382 {
383 int ret;
384
385 mutex_lock(&data->lock);
386 ret = zopt2201_set_resolution(data, zopt2201_scale_als[idx].res);
387 if (ret < 0)
388 goto unlock;
389
390 ret = zopt2201_set_gain(data, zopt2201_scale_als[idx].gain);
391
392 unlock:
393 mutex_unlock(&data->lock);
394 return ret;
395 }
396
zopt2201_write_scale_uvb(struct zopt2201_data * data,int val,int val2)397 static int zopt2201_write_scale_uvb(struct zopt2201_data *data,
398 int val, int val2)
399 {
400 int i;
401
402 for (i = 0; i < ARRAY_SIZE(zopt2201_scale_uvb); i++)
403 if (val == zopt2201_scale_uvb[i].scale &&
404 val2 == zopt2201_scale_uvb[i].uscale)
405 return zopt2201_write_scale_uvb_by_idx(data, i);
406
407 return -EINVAL;
408 }
409
zopt2201_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)410 static int zopt2201_write_raw(struct iio_dev *indio_dev,
411 struct iio_chan_spec const *chan,
412 int val, int val2, long mask)
413 {
414 struct zopt2201_data *data = iio_priv(indio_dev);
415
416 switch (mask) {
417 case IIO_CHAN_INFO_INT_TIME:
418 return zopt2201_write_resolution(data, val, val2);
419 case IIO_CHAN_INFO_SCALE:
420 switch (chan->address) {
421 case ZOPT2201_ALS_DATA:
422 return zopt2201_write_scale_als(data, val, val2);
423 case ZOPT2201_UVB_DATA:
424 return zopt2201_write_scale_uvb(data, val, val2);
425 default:
426 return -EINVAL;
427 }
428 }
429
430 return -EINVAL;
431 }
432
zopt2201_show_int_time_available(struct device * dev,struct device_attribute * attr,char * buf)433 static ssize_t zopt2201_show_int_time_available(struct device *dev,
434 struct device_attribute *attr,
435 char *buf)
436 {
437 size_t len = 0;
438 int i;
439
440 for (i = 0; i < ARRAY_SIZE(zopt2201_resolution); i++)
441 len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06lu ",
442 zopt2201_resolution[i].us);
443 buf[len - 1] = '\n';
444
445 return len;
446 }
447
448 static IIO_DEV_ATTR_INT_TIME_AVAIL(zopt2201_show_int_time_available);
449
zopt2201_show_als_scale_avail(struct device * dev,struct device_attribute * attr,char * buf)450 static ssize_t zopt2201_show_als_scale_avail(struct device *dev,
451 struct device_attribute *attr,
452 char *buf)
453 {
454 ssize_t len = 0;
455 int i;
456
457 for (i = 0; i < ARRAY_SIZE(zopt2201_scale_als); i++)
458 len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06u ",
459 zopt2201_scale_als[i].scale,
460 zopt2201_scale_als[i].uscale);
461 buf[len - 1] = '\n';
462
463 return len;
464 }
465
zopt2201_show_uvb_scale_avail(struct device * dev,struct device_attribute * attr,char * buf)466 static ssize_t zopt2201_show_uvb_scale_avail(struct device *dev,
467 struct device_attribute *attr,
468 char *buf)
469 {
470 ssize_t len = 0;
471 int i;
472
473 for (i = 0; i < ARRAY_SIZE(zopt2201_scale_uvb); i++)
474 len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06u ",
475 zopt2201_scale_uvb[i].scale,
476 zopt2201_scale_uvb[i].uscale);
477 buf[len - 1] = '\n';
478
479 return len;
480 }
481
482 static IIO_DEVICE_ATTR(in_illuminance_scale_available, 0444,
483 zopt2201_show_als_scale_avail, NULL, 0);
484 static IIO_DEVICE_ATTR(in_intensity_uv_scale_available, 0444,
485 zopt2201_show_uvb_scale_avail, NULL, 0);
486
487 static struct attribute *zopt2201_attributes[] = {
488 &iio_dev_attr_integration_time_available.dev_attr.attr,
489 &iio_dev_attr_in_illuminance_scale_available.dev_attr.attr,
490 &iio_dev_attr_in_intensity_uv_scale_available.dev_attr.attr,
491 NULL
492 };
493
494 static const struct attribute_group zopt2201_attribute_group = {
495 .attrs = zopt2201_attributes,
496 };
497
498 static const struct iio_info zopt2201_info = {
499 .read_raw = zopt2201_read_raw,
500 .write_raw = zopt2201_write_raw,
501 .attrs = &zopt2201_attribute_group,
502 };
503
zopt2201_probe(struct i2c_client * client)504 static int zopt2201_probe(struct i2c_client *client)
505 {
506 struct zopt2201_data *data;
507 struct iio_dev *indio_dev;
508 int ret;
509
510 if (!i2c_check_functionality(client->adapter,
511 I2C_FUNC_SMBUS_READ_I2C_BLOCK))
512 return -EOPNOTSUPP;
513
514 ret = i2c_smbus_read_byte_data(client, ZOPT2201_PART_ID);
515 if (ret < 0)
516 return ret;
517 if (ret != ZOPT2201_PART_NUMBER)
518 return -ENODEV;
519
520 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
521 if (!indio_dev)
522 return -ENOMEM;
523
524 data = iio_priv(indio_dev);
525 i2c_set_clientdata(client, indio_dev);
526 data->client = client;
527 mutex_init(&data->lock);
528
529 indio_dev->info = &zopt2201_info;
530 indio_dev->channels = zopt2201_channels;
531 indio_dev->num_channels = ARRAY_SIZE(zopt2201_channels);
532 indio_dev->name = ZOPT2201_DRV_NAME;
533 indio_dev->modes = INDIO_DIRECT_MODE;
534
535 data->rate = ZOPT2201_MEAS_FREQ_100MS;
536 ret = zopt2201_set_resolution(data, ZOPT2201_MEAS_RES_18BIT);
537 if (ret < 0)
538 return ret;
539
540 ret = zopt2201_set_gain(data, ZOPT2201_LS_GAIN_3);
541 if (ret < 0)
542 return ret;
543
544 return devm_iio_device_register(&client->dev, indio_dev);
545 }
546
547 static const struct i2c_device_id zopt2201_id[] = {
548 { "zopt2201" },
549 { }
550 };
551 MODULE_DEVICE_TABLE(i2c, zopt2201_id);
552
553 static struct i2c_driver zopt2201_driver = {
554 .driver = {
555 .name = ZOPT2201_DRV_NAME,
556 },
557 .probe = zopt2201_probe,
558 .id_table = zopt2201_id,
559 };
560
561 module_i2c_driver(zopt2201_driver);
562
563 MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>");
564 MODULE_DESCRIPTION("IDT ZOPT2201 ambient light and UV B sensor driver");
565 MODULE_LICENSE("GPL");
566