1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Vishay VEML3328 RGBCIR light sensor driver
4 *
5 * Copyright (c) 2026 Joshua Crofts <joshua.crofts1@gmail.com>
6 *
7 * Datasheet: https://www.vishay.com/docs/84968/veml3328.pdf
8 */
9
10 #include <linux/array_size.h>
11 #include <linux/bitfield.h>
12 #include <linux/bits.h>
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/pm_runtime.h>
20 #include <linux/regmap.h>
21 #include <linux/regulator/consumer.h>
22 #include <linux/time.h>
23 #include <linux/types.h>
24
25 #include <linux/iio/iio.h>
26
27 #define VEML3328_REG_CONF 0x00
28 #define VEML3328_REG_ID 0x0c
29 #define VEML3328_REG_DATA_C 0x04
30 #define VEML3328_REG_DATA_R 0x05
31 #define VEML3328_REG_DATA_G 0x06
32 #define VEML3328_REG_DATA_B 0x07
33 #define VEML3328_REG_DATA_IR 0x08
34
35 #define VEML3328_CONF_IT_MASK GENMASK(5, 4)
36 #define VEML3328_CONF_GAIN_MASK GENMASK(11, 10)
37
38 #define VEML3328_MAX_IT_TIME (400 * USEC_PER_MSEC)
39
40 #define VEML3328_ID_VAL 0x28
41
42 #define VEML3328_SHUTDOWN (BIT(0) | BIT(15))
43
44 struct veml3328_data {
45 struct regmap *regmap;
46 /* Ensure read-modify-write sequences are not interrupted. */
47 struct mutex lock;
48 };
49
50 static const struct regmap_config veml3328_regmap_config = {
51 .name = "veml3328",
52 .reg_bits = 8,
53 .val_bits = 16,
54 .max_register = VEML3328_REG_ID,
55 .val_format_endian = REGMAP_ENDIAN_LITTLE,
56 };
57
58 #define VEML3328_CHAN_SPEC(_color, _addr) { \
59 .type = IIO_INTENSITY, \
60 .modified = 1, \
61 .channel2 = IIO_MOD_LIGHT_##_color, \
62 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
63 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
64 .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SCALE), \
65 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), \
66 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME), \
67 .address = _addr, \
68 }
69
70 static const struct iio_chan_spec veml3328_channels[] = {
71 {
72 .type = IIO_LIGHT,
73
74 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
75 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
76 .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SCALE),
77 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
78 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME),
79 .address = VEML3328_REG_DATA_G,
80 },
81 VEML3328_CHAN_SPEC(CLEAR, VEML3328_REG_DATA_C),
82 VEML3328_CHAN_SPEC(RED, VEML3328_REG_DATA_R),
83 VEML3328_CHAN_SPEC(GREEN, VEML3328_REG_DATA_G),
84 VEML3328_CHAN_SPEC(BLUE, VEML3328_REG_DATA_B),
85 VEML3328_CHAN_SPEC(IR, VEML3328_REG_DATA_IR),
86 };
87
88 /*
89 * Precomputed scale values (micro units).
90 * Formula for calculation: 0.384 * (50000 / IT_us) * (1 / Gain)
91 * Gain indexes: 0 (x0.5), 1 (x1), 2 (x2), 3 (x4)
92 * IT indexes: 0 (50ms), 1 (100ms), 2 (200ms), 3 (400ms)
93 */
94 static const int veml3328_scale_vals[4][8] = {
95 { 0, 768000, 0, 384000, 0, 192000, 0, 96000 },
96 { 0, 384000, 0, 192000, 0, 96000, 0, 48000 },
97 { 0, 192000, 0, 96000, 0, 48000, 0, 24000 },
98 { 0, 96000, 0, 48000, 0, 24000, 0, 12000 },
99 };
100
101 /* integration times in microseconds */
102 static const int veml3328_it_times[][2] = {
103 { 0, 50 * USEC_PER_MSEC },
104 { 0, 100 * USEC_PER_MSEC },
105 { 0, 200 * USEC_PER_MSEC },
106 { 0, 400 * USEC_PER_MSEC },
107 };
108
veml3328_power_down(struct veml3328_data * data)109 static int veml3328_power_down(struct veml3328_data *data)
110 {
111 return regmap_set_bits(data->regmap, VEML3328_REG_CONF,
112 VEML3328_SHUTDOWN);
113 }
114
veml3328_power_up(struct veml3328_data * data)115 static int veml3328_power_up(struct veml3328_data *data)
116 {
117 int ret;
118
119 ret = regmap_clear_bits(data->regmap, VEML3328_REG_CONF,
120 VEML3328_SHUTDOWN);
121 if (ret)
122 return ret;
123
124 /*
125 * Sleep for maximum integration time to ensure sensor is powered on
126 * correctly.
127 */
128 fsleep(VEML3328_MAX_IT_TIME);
129
130 return 0;
131 }
132
veml3328_power_down_action(void * data)133 static void veml3328_power_down_action(void *data)
134 {
135 veml3328_power_down(data);
136 }
137
veml3328_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)138 static int veml3328_read_raw(struct iio_dev *indio_dev,
139 struct iio_chan_spec const *chan,
140 int *val, int *val2, long mask)
141 {
142 struct veml3328_data *data = iio_priv(indio_dev);
143 struct regmap *regmap = data->regmap;
144 struct device *dev = regmap_get_device(regmap);
145 unsigned int reg_val;
146 int it_inx, gain_inx;
147 int ret;
148
149 PM_RUNTIME_ACQUIRE_IF_ENABLED_AUTOSUSPEND(dev, pm);
150 ret = PM_RUNTIME_ACQUIRE_ERR(&pm);
151 if (ret)
152 return ret;
153
154 switch (mask) {
155 case IIO_CHAN_INFO_RAW:
156 ret = regmap_read(regmap, chan->address, ®_val);
157 if (ret)
158 return ret;
159
160 *val = reg_val;
161 return IIO_VAL_INT;
162
163 case IIO_CHAN_INFO_INT_TIME:
164 ret = regmap_read(regmap, VEML3328_REG_CONF, ®_val);
165 if (ret)
166 return ret;
167
168 it_inx = FIELD_GET(VEML3328_CONF_IT_MASK, reg_val);
169 if (it_inx >= ARRAY_SIZE(veml3328_it_times))
170 return -EINVAL;
171
172 *val = veml3328_it_times[it_inx][0];
173 *val2 = veml3328_it_times[it_inx][1];
174 return IIO_VAL_INT_PLUS_MICRO;
175
176 case IIO_CHAN_INFO_SCALE:
177 ret = regmap_read(regmap, VEML3328_REG_CONF, ®_val);
178 if (ret)
179 return ret;
180
181 it_inx = FIELD_GET(VEML3328_CONF_IT_MASK, reg_val);
182 gain_inx = FIELD_GET(VEML3328_CONF_GAIN_MASK, reg_val);
183
184 if (it_inx >= ARRAY_SIZE(veml3328_it_times) || gain_inx >= 4)
185 return -EINVAL;
186
187 /* Stride by 2 through the flattened array to match (val, val2) */
188 *val = veml3328_scale_vals[it_inx][gain_inx * 2];
189 *val2 = veml3328_scale_vals[it_inx][gain_inx * 2 + 1];
190
191 return IIO_VAL_INT_PLUS_MICRO;
192
193 default:
194 return -EINVAL;
195 }
196 }
197
veml3328_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long mask)198 static int veml3328_read_avail(struct iio_dev *indio_dev,
199 struct iio_chan_spec const *chan,
200 const int **vals, int *type, int *length,
201 long mask)
202 {
203 struct veml3328_data *data = iio_priv(indio_dev);
204 struct regmap *regmap = data->regmap;
205 struct device *dev = regmap_get_device(data->regmap);
206 unsigned int reg_val;
207 int ret, it_inx;
208
209 switch (mask) {
210 case IIO_CHAN_INFO_INT_TIME:
211 *length = ARRAY_SIZE(veml3328_it_times) * 2;
212 *vals = (const int *)veml3328_it_times;
213 *type = IIO_VAL_INT_PLUS_MICRO;
214 return IIO_AVAIL_LIST;
215
216 case IIO_CHAN_INFO_SCALE: {
217 PM_RUNTIME_ACQUIRE_IF_ENABLED_AUTOSUSPEND(dev, pm);
218 ret = PM_RUNTIME_ACQUIRE_ERR(&pm);
219 if (ret)
220 return ret;
221
222 ret = regmap_read(regmap, VEML3328_REG_CONF, ®_val);
223 if (ret)
224 return ret;
225
226 it_inx = FIELD_GET(VEML3328_CONF_IT_MASK, reg_val);
227 if (it_inx >= ARRAY_SIZE(veml3328_it_times))
228 return -EINVAL;
229
230 *length = 8;
231 *vals = (const int *)veml3328_scale_vals[it_inx];
232 *type = IIO_VAL_INT_PLUS_MICRO;
233 return IIO_AVAIL_LIST;
234 }
235 default:
236 return -EINVAL;
237 }
238 }
239
veml3328_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)240 static int veml3328_write_raw(struct iio_dev *indio_dev,
241 struct iio_chan_spec const *chan,
242 int val, int val2, long mask)
243 {
244 struct veml3328_data *data = iio_priv(indio_dev);
245 struct regmap *regmap = data->regmap;
246 struct device *dev = regmap_get_device(regmap);
247 unsigned int reg_val;
248 int i, it_inx;
249 int ret;
250
251 PM_RUNTIME_ACQUIRE_IF_ENABLED_AUTOSUSPEND(dev, pm);
252 ret = PM_RUNTIME_ACQUIRE_ERR(&pm);
253 if (ret)
254 return ret;
255
256 guard(mutex)(&data->lock);
257
258 switch (mask) {
259 case IIO_CHAN_INFO_INT_TIME:
260 if (val != 0)
261 return -EINVAL;
262
263 for (i = 0; i < ARRAY_SIZE(veml3328_it_times); i++) {
264 if (veml3328_it_times[i][1] == val2)
265 break;
266 }
267
268 if (i == ARRAY_SIZE(veml3328_it_times))
269 return -EINVAL;
270
271 return regmap_update_bits(regmap, VEML3328_REG_CONF,
272 VEML3328_CONF_IT_MASK,
273 FIELD_PREP(VEML3328_CONF_IT_MASK, i));
274
275 case IIO_CHAN_INFO_SCALE:
276 ret = regmap_read(regmap, VEML3328_REG_CONF, ®_val);
277 if (ret)
278 return ret;
279
280 it_inx = FIELD_GET(VEML3328_CONF_IT_MASK, reg_val);
281 if (it_inx >= ARRAY_SIZE(veml3328_it_times))
282 return -EINVAL;
283
284 for (i = 0; i < 4; i++) {
285 if (val == veml3328_scale_vals[it_inx][i * 2] &&
286 val2 == veml3328_scale_vals[it_inx][i * 2 + 1])
287 break;
288 }
289
290 if (i == 4)
291 return -EINVAL;
292
293 return regmap_update_bits(regmap, VEML3328_REG_CONF,
294 VEML3328_CONF_GAIN_MASK,
295 FIELD_PREP(VEML3328_CONF_GAIN_MASK, i));
296
297 default:
298 return -EINVAL;
299 }
300 }
301
302 static const struct iio_info veml3328_info = {
303 .read_raw = veml3328_read_raw,
304 .write_raw = veml3328_write_raw,
305 .read_avail = veml3328_read_avail,
306 };
307
veml3328_probe(struct i2c_client * client)308 static int veml3328_probe(struct i2c_client *client)
309 {
310 struct device *dev = &client->dev;
311 struct veml3328_data *data;
312 struct iio_dev *indio_dev;
313 unsigned int reg_val;
314 int ret;
315
316 indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
317 if (!indio_dev)
318 return -ENOMEM;
319
320 data = iio_priv(indio_dev);
321 i2c_set_clientdata(client, indio_dev);
322
323 data->regmap = devm_regmap_init_i2c(client, &veml3328_regmap_config);
324 if (IS_ERR(data->regmap))
325 return dev_err_probe(dev, PTR_ERR(data->regmap),
326 "Failed to initialize regmap\n");
327
328 ret = devm_mutex_init(dev, &data->lock);
329 if (ret)
330 return ret;
331
332 ret = devm_regulator_get_enable(dev, "vdd");
333 if (ret)
334 return dev_err_probe(dev, ret, "Failed to enable regulator\n");
335
336 ret = regmap_read(data->regmap, VEML3328_REG_ID, ®_val);
337 if (ret)
338 return dev_err_probe(dev, ret, "Failed to read ID register\n");
339
340 if ((reg_val & 0xff) != VEML3328_ID_VAL)
341 dev_warn(dev, "Unknown device ID: 0x%02x\n", reg_val & 0xff);
342
343 ret = veml3328_power_up(data);
344 if (ret)
345 return dev_err_probe(dev, ret, "Failed to power on sensor\n");
346
347 ret = devm_add_action_or_reset(dev, veml3328_power_down_action, data);
348 if (ret)
349 return dev_err_probe(dev, ret, "Failed to register teardown\n");
350
351 indio_dev->name = "veml3328";
352 indio_dev->modes = INDIO_DIRECT_MODE;
353 indio_dev->info = &veml3328_info;
354 indio_dev->channels = veml3328_channels;
355 indio_dev->num_channels = ARRAY_SIZE(veml3328_channels);
356
357 pm_runtime_set_active(dev);
358 pm_runtime_set_autosuspend_delay(dev, 2000);
359 pm_runtime_use_autosuspend(dev);
360
361 ret = devm_pm_runtime_enable(dev);
362 if (ret)
363 return dev_err_probe(dev, ret, "Failed to enable runtime PM\n");
364
365 return devm_iio_device_register(dev, indio_dev);
366 }
367
veml3328_runtime_suspend(struct device * dev)368 static int veml3328_runtime_suspend(struct device *dev)
369 {
370 struct veml3328_data *data = iio_priv(dev_get_drvdata(dev));
371 int ret;
372
373 ret = veml3328_power_down(data);
374 if (ret)
375 dev_err(dev, "Failed to suspend: %d\n", ret);
376
377 return ret;
378 }
379
veml3328_runtime_resume(struct device * dev)380 static int veml3328_runtime_resume(struct device *dev)
381 {
382 struct veml3328_data *data = iio_priv(dev_get_drvdata(dev));
383 int ret;
384
385 ret = veml3328_power_up(data);
386 if (ret)
387 dev_err(dev, "Failed to resume: %d\n", ret);
388
389 return ret;
390 }
391
392 static DEFINE_RUNTIME_DEV_PM_OPS(veml3328_pm_ops,
393 veml3328_runtime_suspend,
394 veml3328_runtime_resume,
395 NULL);
396
397 static const struct of_device_id veml3328_of_match[] = {
398 { .compatible = "vishay,veml3328" },
399 { }
400 };
401 MODULE_DEVICE_TABLE(of, veml3328_of_match);
402
403 static const struct i2c_device_id veml3328_id[] = {
404 { .name = "veml3328" },
405 { }
406 };
407 MODULE_DEVICE_TABLE(i2c, veml3328_id);
408
409 static struct i2c_driver veml3328_driver = {
410 .driver = {
411 .name = "veml3328",
412 .of_match_table = veml3328_of_match,
413 .pm = pm_ptr(&veml3328_pm_ops),
414 },
415 .probe = veml3328_probe,
416 .id_table = veml3328_id,
417 };
418 module_i2c_driver(veml3328_driver);
419
420 MODULE_AUTHOR("Joshua Crofts <joshua.crofts1@gmail.com>");
421 MODULE_DESCRIPTION("VEML3328 RGBCIR Light Sensor");
422 MODULE_LICENSE("GPL");
423