1 // SPDX-License-Identifier: GPL-2.0-only
3 * Vishay VEML6075 UVA and UVB light sensor
5 * Copyright 2023 Javier Carrasco <javier.carrasco.cruz@gmail.com>
7 * 7-bit I2C slave, address 0x10
10 #include <linux/bitfield.h>
11 #include <linux/delay.h>
12 #include <linux/err.h>
13 #include <linux/i2c.h>
14 #include <linux/module.h>
15 #include <linux/mutex.h>
16 #include <linux/regmap.h>
17 #include <linux/units.h>
19 #include <linux/iio/iio.h>
21 #define VEML6075_CMD_CONF 0x00 /* configuration register */
22 #define VEML6075_CMD_UVA 0x07 /* UVA channel */
23 #define VEML6075_CMD_UVB 0x09 /* UVB channel */
24 #define VEML6075_CMD_COMP1 0x0A /* visible light compensation */
25 #define VEML6075_CMD_COMP2 0x0B /* infrarred light compensation */
26 #define VEML6075_CMD_ID 0x0C /* device ID */
28 #define VEML6075_CONF_IT GENMASK(6, 4) /* intregration time */
29 #define VEML6075_CONF_HD BIT(3) /* dynamic setting */
30 #define VEML6075_CONF_TRIG BIT(2) /* trigger */
31 #define VEML6075_CONF_AF BIT(1) /* active force enable */
32 #define VEML6075_CONF_SD BIT(0) /* shutdown */
34 #define VEML6075_IT_50_MS 0x00
35 #define VEML6075_IT_100_MS 0x01
36 #define VEML6075_IT_200_MS 0x02
37 #define VEML6075_IT_400_MS 0x03
38 #define VEML6075_IT_800_MS 0x04
40 #define VEML6075_AF_DISABLE 0x00
41 #define VEML6075_AF_ENABLE 0x01
43 #define VEML6075_SD_DISABLE 0x00
44 #define VEML6075_SD_ENABLE 0x01
46 /* Open-air coefficients and responsivity */
47 #define VEML6075_A_COEF 2220
48 #define VEML6075_B_COEF 1330
49 #define VEML6075_C_COEF 2950
50 #define VEML6075_D_COEF 1740
51 #define VEML6075_UVA_RESP 1461
52 #define VEML6075_UVB_RESP 2591
54 static const int veml6075_it_ms[] = { 50, 100, 200, 400, 800 };
56 struct veml6075_data {
57 struct i2c_client *client;
58 struct regmap *regmap;
60 * prevent integration time modification and triggering
61 * measurements while a measurement is underway.
72 static const struct iio_chan_spec veml6075_channels[] = {
74 .type = IIO_INTENSITY,
77 .channel2 = IIO_MOD_LIGHT_UVA,
78 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
79 BIT(IIO_CHAN_INFO_SCALE),
80 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
81 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME),
84 .type = IIO_INTENSITY,
87 .channel2 = IIO_MOD_LIGHT_UVB,
88 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
89 BIT(IIO_CHAN_INFO_SCALE),
90 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
91 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME),
95 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
96 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
97 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME),
101 static int veml6075_request_measurement(struct veml6075_data *data)
103 int ret, conf, int_time;
105 ret = regmap_read(data->regmap, VEML6075_CMD_CONF, &conf);
109 /* disable shutdown and trigger measurement */
110 ret = regmap_write(data->regmap, VEML6075_CMD_CONF,
111 (conf | VEML6075_CONF_TRIG) & ~VEML6075_CONF_SD);
116 * A measurement requires between 1.30 and 1.40 times the integration
117 * time for all possible configurations. Using a 1.50 factor simplifies
118 * operations and ensures reliability under all circumstances.
120 int_time = veml6075_it_ms[FIELD_GET(VEML6075_CONF_IT, conf)];
121 msleep(int_time + (int_time / 2));
123 /* shutdown again, data registers are still accessible */
124 return regmap_update_bits(data->regmap, VEML6075_CMD_CONF,
125 VEML6075_CONF_SD, VEML6075_CONF_SD);
128 static int veml6075_uva_comp(int raw_uva, int comp1, int comp2)
130 int comp1a_c, comp2a_c, uva_comp;
132 comp1a_c = (comp1 * VEML6075_A_COEF) / 1000U;
133 comp2a_c = (comp2 * VEML6075_B_COEF) / 1000U;
134 uva_comp = raw_uva - comp1a_c - comp2a_c;
136 return clamp_val(uva_comp, 0, U16_MAX);
139 static int veml6075_uvb_comp(int raw_uvb, int comp1, int comp2)
141 int comp1b_c, comp2b_c, uvb_comp;
143 comp1b_c = (comp1 * VEML6075_C_COEF) / 1000U;
144 comp2b_c = (comp2 * VEML6075_D_COEF) / 1000U;
145 uvb_comp = raw_uvb - comp1b_c - comp2b_c;
147 return clamp_val(uvb_comp, 0, U16_MAX);
150 static int veml6075_read_comp(struct veml6075_data *data, int *c1, int *c2)
154 ret = regmap_read(data->regmap, VEML6075_CMD_COMP1, c1);
158 return regmap_read(data->regmap, VEML6075_CMD_COMP2, c2);
161 static int veml6075_read_uv_direct(struct veml6075_data *data, int chan,
166 guard(mutex)(&data->lock);
168 ret = veml6075_request_measurement(data);
172 ret = veml6075_read_comp(data, &c1, &c2);
178 ret = regmap_read(data->regmap, VEML6075_CMD_UVA, val);
182 *val = veml6075_uva_comp(*val, c1, c2);
185 ret = regmap_read(data->regmap, VEML6075_CMD_UVB, val);
189 *val = veml6075_uvb_comp(*val, c1, c2);
196 static int veml6075_read_int_time_index(struct veml6075_data *data)
200 ret = regmap_read(data->regmap, VEML6075_CMD_CONF, &conf);
204 return FIELD_GET(VEML6075_CONF_IT, conf);
207 static int veml6075_read_int_time_ms(struct veml6075_data *data, int *val)
211 guard(mutex)(&data->lock);
212 int_index = veml6075_read_int_time_index(data);
216 *val = veml6075_it_ms[int_index];
221 static int veml6075_get_uvi_micro(struct veml6075_data *data, int uva_comp,
224 int uvia_micro = uva_comp * VEML6075_UVA_RESP;
225 int uvib_micro = uvb_comp * VEML6075_UVB_RESP;
228 int_index = veml6075_read_int_time_index(data);
233 case VEML6075_IT_50_MS:
234 return uvia_micro + uvib_micro;
235 case VEML6075_IT_100_MS:
236 case VEML6075_IT_200_MS:
237 case VEML6075_IT_400_MS:
238 case VEML6075_IT_800_MS:
239 return (uvia_micro + uvib_micro) / (2 << int_index);
245 static int veml6075_read_uvi(struct veml6075_data *data, int *val, int *val2)
247 int ret, c1, c2, uva, uvb, uvi_micro;
249 guard(mutex)(&data->lock);
251 ret = veml6075_request_measurement(data);
255 ret = veml6075_read_comp(data, &c1, &c2);
259 ret = regmap_read(data->regmap, VEML6075_CMD_UVA, &uva);
263 ret = regmap_read(data->regmap, VEML6075_CMD_UVB, &uvb);
267 uvi_micro = veml6075_get_uvi_micro(data, veml6075_uva_comp(uva, c1, c2),
268 veml6075_uvb_comp(uvb, c1, c2));
272 *val = uvi_micro / MICRO;
273 *val2 = uvi_micro % MICRO;
275 return IIO_VAL_INT_PLUS_MICRO;
278 static int veml6075_read_responsivity(int chan, int *val, int *val2)
280 /* scale = 1 / resp */
283 /* resp = 0.93 c/uW/cm2: scale = 1.75268817 */
286 return IIO_VAL_INT_PLUS_NANO;
288 /* resp = 2.1 c/uW/cm2: scale = 0.476190476 */
291 return IIO_VAL_INT_PLUS_NANO;
297 static int veml6075_read_avail(struct iio_dev *indio_dev,
298 struct iio_chan_spec const *chan,
299 const int **vals, int *type, int *length,
303 case IIO_CHAN_INFO_INT_TIME:
304 *length = ARRAY_SIZE(veml6075_it_ms);
305 *vals = veml6075_it_ms;
307 return IIO_AVAIL_LIST;
314 static int veml6075_read_raw(struct iio_dev *indio_dev,
315 struct iio_chan_spec const *chan,
316 int *val, int *val2, long mask)
318 struct veml6075_data *data = iio_priv(indio_dev);
321 case IIO_CHAN_INFO_RAW:
322 return veml6075_read_uv_direct(data, chan->channel, val);
323 case IIO_CHAN_INFO_PROCESSED:
324 return veml6075_read_uvi(data, val, val2);
325 case IIO_CHAN_INFO_INT_TIME:
326 return veml6075_read_int_time_ms(data, val);
327 case IIO_CHAN_INFO_SCALE:
328 return veml6075_read_responsivity(chan->channel, val, val2);
334 static int veml6075_write_int_time_ms(struct veml6075_data *data, int val)
336 int i = ARRAY_SIZE(veml6075_it_ms);
338 guard(mutex)(&data->lock);
341 if (val == veml6075_it_ms[i])
347 return regmap_update_bits(data->regmap, VEML6075_CMD_CONF,
349 FIELD_PREP(VEML6075_CONF_IT, i));
352 static int veml6075_write_raw(struct iio_dev *indio_dev,
353 struct iio_chan_spec const *chan,
354 int val, int val2, long mask)
356 struct veml6075_data *data = iio_priv(indio_dev);
359 case IIO_CHAN_INFO_INT_TIME:
360 return veml6075_write_int_time_ms(data, val);
366 static const struct iio_info veml6075_info = {
367 .read_avail = veml6075_read_avail,
368 .read_raw = veml6075_read_raw,
369 .write_raw = veml6075_write_raw,
372 static bool veml6075_readable_reg(struct device *dev, unsigned int reg)
375 case VEML6075_CMD_CONF:
376 case VEML6075_CMD_UVA:
377 case VEML6075_CMD_UVB:
378 case VEML6075_CMD_COMP1:
379 case VEML6075_CMD_COMP2:
380 case VEML6075_CMD_ID:
387 static bool veml6075_writable_reg(struct device *dev, unsigned int reg)
390 case VEML6075_CMD_CONF:
397 static const struct regmap_config veml6075_regmap_config = {
401 .max_register = VEML6075_CMD_ID,
402 .readable_reg = veml6075_readable_reg,
403 .writeable_reg = veml6075_writable_reg,
404 .val_format_endian = REGMAP_ENDIAN_LITTLE,
407 static int veml6075_probe(struct i2c_client *client)
409 struct veml6075_data *data;
410 struct iio_dev *indio_dev;
411 struct regmap *regmap;
414 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
418 regmap = devm_regmap_init_i2c(client, &veml6075_regmap_config);
420 return PTR_ERR(regmap);
422 data = iio_priv(indio_dev);
423 data->client = client;
424 data->regmap = regmap;
426 mutex_init(&data->lock);
428 indio_dev->name = "veml6075";
429 indio_dev->info = &veml6075_info;
430 indio_dev->channels = veml6075_channels;
431 indio_dev->num_channels = ARRAY_SIZE(veml6075_channels);
432 indio_dev->modes = INDIO_DIRECT_MODE;
434 ret = devm_regulator_get_enable(&client->dev, "vdd");
438 /* default: 100ms integration time, active force enable, shutdown */
439 config = FIELD_PREP(VEML6075_CONF_IT, VEML6075_IT_100_MS) |
440 FIELD_PREP(VEML6075_CONF_AF, VEML6075_AF_ENABLE) |
441 FIELD_PREP(VEML6075_CONF_SD, VEML6075_SD_ENABLE);
442 ret = regmap_write(data->regmap, VEML6075_CMD_CONF, config);
446 return devm_iio_device_register(&client->dev, indio_dev);
449 static const struct i2c_device_id veml6075_id[] = {
453 MODULE_DEVICE_TABLE(i2c, veml6075_id);
455 static const struct of_device_id veml6075_of_match[] = {
456 { .compatible = "vishay,veml6075" },
459 MODULE_DEVICE_TABLE(of, veml6075_of_match);
461 static struct i2c_driver veml6075_driver = {
464 .of_match_table = veml6075_of_match,
466 .probe = veml6075_probe,
467 .id_table = veml6075_id,
470 module_i2c_driver(veml6075_driver);
472 MODULE_AUTHOR("Javier Carrasco <javier.carrasco.cruz@gmail.com>");
473 MODULE_DESCRIPTION("Vishay VEML6075 UVA and UVB light sensor driver");
474 MODULE_LICENSE("GPL");