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 <asm/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
74struct zopt2201_data {
75 struct i2c_client *client;
76 struct mutex lock;
77 u8 gain;
78 u8 res;
79 u8 rate;
80};
81
82static 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
93static 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
104static 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
116static 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
145static 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
174static 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(client: data->client, ZOPT2201_MAIN_CTRL, value: out);
182}
183
184static 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, uvb_mode: 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(min: t, max: t + 1000);
201 else
202 msleep(msecs: 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, command: reg, length: sizeof(buf), values: buf);
216 if (ret < 0)
217 goto fail;
218
219 ret = i2c_smbus_write_byte_data(client, ZOPT2201_MAIN_CTRL, value: 0x00);
220 if (ret < 0)
221 goto fail;
222 mutex_unlock(lock: &data->lock);
223
224 return get_unaligned_le24(p: &buf[0]);
225
226fail:
227 mutex_unlock(lock: &data->lock);
228 return ret;
229}
230
231static 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
254static 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, reg: 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(dividend: *val * 1000000ULL, divisor: *val2);
292 *val = div_s64_rem(dividend: tmp, divisor: 1000000, remainder: 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
304static int zopt2201_set_resolution(struct zopt2201_data *data, u8 res)
305{
306 int ret;
307
308 ret = i2c_smbus_write_byte_data(client: data->client, ZOPT2201_LS_MEAS_RATE,
309 value: (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
319static 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, res: i);
331 mutex_unlock(lock: &data->lock);
332 return ret;
333 }
334
335 return -EINVAL;
336}
337
338static int zopt2201_set_gain(struct zopt2201_data *data, u8 gain)
339{
340 int ret;
341
342 ret = i2c_smbus_write_byte_data(client: data->client, ZOPT2201_LS_GAIN, value: gain);
343 if (ret < 0)
344 return ret;
345
346 data->gain = gain;
347
348 return 0;
349}
350
351static 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, res: zopt2201_scale_als[idx].res);
357 if (ret < 0)
358 goto unlock;
359
360 ret = zopt2201_set_gain(data, gain: zopt2201_scale_als[idx].gain);
361
362unlock:
363 mutex_unlock(lock: &data->lock);
364 return ret;
365}
366
367static 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, idx: i);
376 }
377
378 return -EINVAL;
379}
380
381static 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, res: zopt2201_scale_als[idx].res);
387 if (ret < 0)
388 goto unlock;
389
390 ret = zopt2201_set_gain(data, gain: zopt2201_scale_als[idx].gain);
391
392unlock:
393 mutex_unlock(lock: &data->lock);
394 return ret;
395}
396
397static 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, idx: i);
406
407 return -EINVAL;
408}
409
410static 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
433static 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: buf + len, PAGE_SIZE - len, fmt: "0.%06lu ",
442 zopt2201_resolution[i].us);
443 buf[len - 1] = '\n';
444
445 return len;
446}
447
448static IIO_DEV_ATTR_INT_TIME_AVAIL(zopt2201_show_int_time_available);
449
450static 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: buf + len, PAGE_SIZE - len, fmt: "%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
466static 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: buf + len, PAGE_SIZE - len, fmt: "%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
482static IIO_DEVICE_ATTR(in_illuminance_scale_available, 0444,
483 zopt2201_show_als_scale_avail, NULL, 0);
484static IIO_DEVICE_ATTR(in_intensity_uv_scale_available, 0444,
485 zopt2201_show_uvb_scale_avail, NULL, 0);
486
487static 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
494static const struct attribute_group zopt2201_attribute_group = {
495 .attrs = zopt2201_attributes,
496};
497
498static 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
504static 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(adap: 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(parent: &client->dev, sizeof_priv: sizeof(*data));
521 if (!indio_dev)
522 return -ENOMEM;
523
524 data = iio_priv(indio_dev);
525 i2c_set_clientdata(client, data: 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
547static const struct i2c_device_id zopt2201_id[] = {
548 { "zopt2201", 0 },
549 { }
550};
551MODULE_DEVICE_TABLE(i2c, zopt2201_id);
552
553static struct i2c_driver zopt2201_driver = {
554 .driver = {
555 .name = ZOPT2201_DRV_NAME,
556 },
557 .probe = zopt2201_probe,
558 .id_table = zopt2201_id,
559};
560
561module_i2c_driver(zopt2201_driver);
562
563MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>");
564MODULE_DESCRIPTION("IDT ZOPT2201 ambient light and UV B sensor driver");
565MODULE_LICENSE("GPL");
566

source code of linux/drivers/iio/light/zopt2201.c