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/cleanup.h>
14 #include <linux/delay.h>
15 #include <linux/err.h>
16 #include <linux/i2c.h>
17 #include <linux/module.h>
18 #include <linux/mutex.h>
19 #include <linux/unaligned.h>
20
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.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 const 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 const 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 guard(mutex)(&data->lock);
190 ret = zopt2201_enable_mode(data, reg == ZOPT2201_UVB_DATA);
191 if (ret < 0)
192 return ret;
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 return ret;
204 if (ret & ZOPT2201_MAIN_STATUS_DRDY)
205 break;
206 }
207
208 if (tries < 0) {
209 ret = -ETIMEDOUT;
210 return ret;
211 }
212
213 ret = i2c_smbus_read_i2c_block_data(client, reg, sizeof(buf), buf);
214 if (ret < 0)
215 return ret;
216
217 ret = i2c_smbus_write_byte_data(client, ZOPT2201_MAIN_CTRL, 0x00);
218 if (ret < 0)
219 return ret;
220
221 return get_unaligned_le24(&buf[0]);
222 }
223
224 static const struct iio_chan_spec zopt2201_channels[] = {
225 {
226 .type = IIO_LIGHT,
227 .address = ZOPT2201_ALS_DATA,
228 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
229 BIT(IIO_CHAN_INFO_SCALE),
230 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
231 },
232 {
233 .type = IIO_INTENSITY,
234 .modified = 1,
235 .channel2 = IIO_MOD_LIGHT_UV,
236 .address = ZOPT2201_UVB_DATA,
237 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
238 BIT(IIO_CHAN_INFO_SCALE),
239 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
240 },
241 {
242 .type = IIO_UVINDEX,
243 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
244 },
245 };
246
zopt2201_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)247 static int zopt2201_read_raw(struct iio_dev *indio_dev,
248 struct iio_chan_spec const *chan,
249 int *val, int *val2, long mask)
250 {
251 struct zopt2201_data *data = iio_priv(indio_dev);
252 u64 tmp;
253 int ret;
254
255 switch (mask) {
256 case IIO_CHAN_INFO_RAW:
257 ret = zopt2201_read(data, chan->address);
258 if (ret < 0)
259 return ret;
260 *val = ret;
261 return IIO_VAL_INT;
262 case IIO_CHAN_INFO_PROCESSED:
263 ret = zopt2201_read(data, ZOPT2201_UVB_DATA);
264 if (ret < 0)
265 return ret;
266 *val = ret * 18 *
267 (1 << (20 - zopt2201_resolution[data->res].bits)) /
268 zopt2201_gain_uvb[data->gain].gain;
269 return IIO_VAL_INT;
270 case IIO_CHAN_INFO_SCALE:
271 switch (chan->address) {
272 case ZOPT2201_ALS_DATA:
273 *val = zopt2201_gain_als[data->gain].scale;
274 break;
275 case ZOPT2201_UVB_DATA:
276 *val = zopt2201_gain_uvb[data->gain].scale;
277 break;
278 default:
279 return -EINVAL;
280 }
281
282 *val2 = 1000000;
283 *val2 *= (1 << (zopt2201_resolution[data->res].bits - 13));
284 tmp = div_s64(*val * 1000000ULL, *val2);
285 *val = div_s64_rem(tmp, 1000000, val2);
286
287 return IIO_VAL_INT_PLUS_MICRO;
288 case IIO_CHAN_INFO_INT_TIME:
289 *val = 0;
290 *val2 = zopt2201_resolution[data->res].us;
291 return IIO_VAL_INT_PLUS_MICRO;
292 default:
293 return -EINVAL;
294 }
295 }
296
zopt2201_set_resolution(struct zopt2201_data * data,u8 res)297 static int zopt2201_set_resolution(struct zopt2201_data *data, u8 res)
298 {
299 int ret;
300
301 ret = i2c_smbus_write_byte_data(data->client, ZOPT2201_LS_MEAS_RATE,
302 (res << ZOPT2201_MEAS_RES_SHIFT) |
303 data->rate);
304 if (ret < 0)
305 return ret;
306
307 data->res = res;
308
309 return 0;
310 }
311
zopt2201_write_resolution(struct zopt2201_data * data,int val,int val2)312 static int zopt2201_write_resolution(struct zopt2201_data *data,
313 int val, int val2)
314 {
315 int i;
316
317 if (val != 0)
318 return -EINVAL;
319
320 for (i = 0; i < ARRAY_SIZE(zopt2201_resolution); i++)
321 if (val2 == zopt2201_resolution[i].us) {
322 guard(mutex)(&data->lock);
323 return zopt2201_set_resolution(data, i);
324 }
325
326 return -EINVAL;
327 }
328
zopt2201_set_gain(struct zopt2201_data * data,u8 gain)329 static int zopt2201_set_gain(struct zopt2201_data *data, u8 gain)
330 {
331 int ret;
332
333 ret = i2c_smbus_write_byte_data(data->client, ZOPT2201_LS_GAIN, gain);
334 if (ret < 0)
335 return ret;
336
337 data->gain = gain;
338
339 return 0;
340 }
341
zopt2201_write_scale_by_idx(struct zopt2201_data * data,int idx,const struct zopt2201_scale * zopt2201_scale_array)342 static int zopt2201_write_scale_by_idx(struct zopt2201_data *data, int idx,
343 const struct zopt2201_scale *zopt2201_scale_array)
344 {
345 int ret;
346
347 guard(mutex)(&data->lock);
348 ret = zopt2201_set_resolution(data, zopt2201_scale_array[idx].res);
349 if (ret < 0)
350 return ret;
351
352 return zopt2201_set_gain(data, zopt2201_scale_array[idx].gain);
353 }
354
zopt2201_write_scale_als(struct zopt2201_data * data,int val,int val2)355 static int zopt2201_write_scale_als(struct zopt2201_data *data,
356 int val, int val2)
357 {
358 int i;
359
360 for (i = 0; i < ARRAY_SIZE(zopt2201_scale_als); i++)
361 if (val == zopt2201_scale_als[i].scale &&
362 val2 == zopt2201_scale_als[i].uscale)
363 return zopt2201_write_scale_by_idx(data, i, zopt2201_scale_als);
364
365 return -EINVAL;
366 }
367
zopt2201_write_scale_uvb(struct zopt2201_data * data,int val,int val2)368 static int zopt2201_write_scale_uvb(struct zopt2201_data *data,
369 int val, int val2)
370 {
371 int i;
372
373 for (i = 0; i < ARRAY_SIZE(zopt2201_scale_uvb); i++)
374 if (val == zopt2201_scale_uvb[i].scale &&
375 val2 == zopt2201_scale_uvb[i].uscale)
376 return zopt2201_write_scale_by_idx(data, i, zopt2201_scale_uvb);
377
378 return -EINVAL;
379 }
380
zopt2201_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)381 static int zopt2201_write_raw(struct iio_dev *indio_dev,
382 struct iio_chan_spec const *chan,
383 int val, int val2, long mask)
384 {
385 struct zopt2201_data *data = iio_priv(indio_dev);
386
387 switch (mask) {
388 case IIO_CHAN_INFO_INT_TIME:
389 return zopt2201_write_resolution(data, val, val2);
390 case IIO_CHAN_INFO_SCALE:
391 switch (chan->address) {
392 case ZOPT2201_ALS_DATA:
393 return zopt2201_write_scale_als(data, val, val2);
394 case ZOPT2201_UVB_DATA:
395 return zopt2201_write_scale_uvb(data, val, val2);
396 default:
397 return -EINVAL;
398 }
399 }
400
401 return -EINVAL;
402 }
403
zopt2201_show_int_time_available(struct device * dev,struct device_attribute * attr,char * buf)404 static ssize_t zopt2201_show_int_time_available(struct device *dev,
405 struct device_attribute *attr,
406 char *buf)
407 {
408 size_t len = 0;
409 int i;
410
411 for (i = 0; i < ARRAY_SIZE(zopt2201_resolution); i++)
412 len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06lu ",
413 zopt2201_resolution[i].us);
414 buf[len - 1] = '\n';
415
416 return len;
417 }
418
419 static IIO_DEV_ATTR_INT_TIME_AVAIL(zopt2201_show_int_time_available);
420
zopt2201_show_als_scale_avail(struct device * dev,struct device_attribute * attr,char * buf)421 static ssize_t zopt2201_show_als_scale_avail(struct device *dev,
422 struct device_attribute *attr,
423 char *buf)
424 {
425 ssize_t len = 0;
426 int i;
427
428 for (i = 0; i < ARRAY_SIZE(zopt2201_scale_als); i++)
429 len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06u ",
430 zopt2201_scale_als[i].scale,
431 zopt2201_scale_als[i].uscale);
432 buf[len - 1] = '\n';
433
434 return len;
435 }
436
zopt2201_show_uvb_scale_avail(struct device * dev,struct device_attribute * attr,char * buf)437 static ssize_t zopt2201_show_uvb_scale_avail(struct device *dev,
438 struct device_attribute *attr,
439 char *buf)
440 {
441 ssize_t len = 0;
442 int i;
443
444 for (i = 0; i < ARRAY_SIZE(zopt2201_scale_uvb); i++)
445 len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06u ",
446 zopt2201_scale_uvb[i].scale,
447 zopt2201_scale_uvb[i].uscale);
448 buf[len - 1] = '\n';
449
450 return len;
451 }
452
453 static IIO_DEVICE_ATTR(in_illuminance_scale_available, 0444,
454 zopt2201_show_als_scale_avail, NULL, 0);
455 static IIO_DEVICE_ATTR(in_intensity_uv_scale_available, 0444,
456 zopt2201_show_uvb_scale_avail, NULL, 0);
457
458 static struct attribute *zopt2201_attributes[] = {
459 &iio_dev_attr_integration_time_available.dev_attr.attr,
460 &iio_dev_attr_in_illuminance_scale_available.dev_attr.attr,
461 &iio_dev_attr_in_intensity_uv_scale_available.dev_attr.attr,
462 NULL
463 };
464
465 static const struct attribute_group zopt2201_attribute_group = {
466 .attrs = zopt2201_attributes,
467 };
468
469 static const struct iio_info zopt2201_info = {
470 .read_raw = zopt2201_read_raw,
471 .write_raw = zopt2201_write_raw,
472 .attrs = &zopt2201_attribute_group,
473 };
474
zopt2201_probe(struct i2c_client * client)475 static int zopt2201_probe(struct i2c_client *client)
476 {
477 struct zopt2201_data *data;
478 struct iio_dev *indio_dev;
479 int ret;
480
481 if (!i2c_check_functionality(client->adapter,
482 I2C_FUNC_SMBUS_READ_I2C_BLOCK))
483 return -EOPNOTSUPP;
484
485 ret = i2c_smbus_read_byte_data(client, ZOPT2201_PART_ID);
486 if (ret < 0)
487 return ret;
488 if (ret != ZOPT2201_PART_NUMBER)
489 return -ENODEV;
490
491 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
492 if (!indio_dev)
493 return -ENOMEM;
494
495 data = iio_priv(indio_dev);
496 i2c_set_clientdata(client, indio_dev);
497 data->client = client;
498 mutex_init(&data->lock);
499
500 indio_dev->info = &zopt2201_info;
501 indio_dev->channels = zopt2201_channels;
502 indio_dev->num_channels = ARRAY_SIZE(zopt2201_channels);
503 indio_dev->name = ZOPT2201_DRV_NAME;
504 indio_dev->modes = INDIO_DIRECT_MODE;
505
506 data->rate = ZOPT2201_MEAS_FREQ_100MS;
507 ret = zopt2201_set_resolution(data, ZOPT2201_MEAS_RES_18BIT);
508 if (ret < 0)
509 return ret;
510
511 ret = zopt2201_set_gain(data, ZOPT2201_LS_GAIN_3);
512 if (ret < 0)
513 return ret;
514
515 return devm_iio_device_register(&client->dev, indio_dev);
516 }
517
518 static const struct i2c_device_id zopt2201_id[] = {
519 { "zopt2201" },
520 { }
521 };
522 MODULE_DEVICE_TABLE(i2c, zopt2201_id);
523
524 static struct i2c_driver zopt2201_driver = {
525 .driver = {
526 .name = ZOPT2201_DRV_NAME,
527 },
528 .probe = zopt2201_probe,
529 .id_table = zopt2201_id,
530 };
531
532 module_i2c_driver(zopt2201_driver);
533
534 MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>");
535 MODULE_DESCRIPTION("IDT ZOPT2201 ambient light and UV B sensor driver");
536 MODULE_LICENSE("GPL");
537