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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * vl6180.c - Support for STMicroelectronics VL6180 ALS, range and proximity
4 * sensor
5 *
6 * Copyright 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net>
7 * Copyright 2017 Manivannan Sadhasivam <manivannanece23@gmail.com>
8 *
9 * IIO driver for VL6180 (7-bit I2C slave address 0x29)
10 *
11 * Range: 0 to 100mm
12 * ALS: < 1 Lux up to 100 kLux
13 * IR: 850nm
14 *
15 * TODO: irq, threshold events, continuous mode, hardware buffer
16 */
17
18#include <linux/module.h>
19#include <linux/mod_devicetable.h>
20#include <linux/i2c.h>
21#include <linux/mutex.h>
22#include <linux/err.h>
23#include <linux/of.h>
24#include <linux/delay.h>
25#include <linux/util_macros.h>
26
27#include <linux/iio/iio.h>
28#include <linux/iio/sysfs.h>
29
30#define VL6180_DRV_NAME "vl6180"
31
32/* Device identification register and value */
33#define VL6180_MODEL_ID 0x000
34#define VL6180_MODEL_ID_VAL 0xb4
35
36/* Configuration registers */
37#define VL6180_INTR_CONFIG 0x014
38#define VL6180_INTR_CLEAR 0x015
39#define VL6180_OUT_OF_RESET 0x016
40#define VL6180_HOLD 0x017
41#define VL6180_RANGE_START 0x018
42#define VL6180_ALS_START 0x038
43#define VL6180_ALS_GAIN 0x03f
44#define VL6180_ALS_IT 0x040
45
46/* Status registers */
47#define VL6180_RANGE_STATUS 0x04d
48#define VL6180_ALS_STATUS 0x04e
49#define VL6180_INTR_STATUS 0x04f
50
51/* Result value registers */
52#define VL6180_ALS_VALUE 0x050
53#define VL6180_RANGE_VALUE 0x062
54#define VL6180_RANGE_RATE 0x066
55
56/* bits of the RANGE_START and ALS_START register */
57#define VL6180_MODE_CONT BIT(1) /* continuous mode */
58#define VL6180_STARTSTOP BIT(0) /* start measurement, auto-reset */
59
60/* bits of the INTR_STATUS and INTR_CONFIG register */
61#define VL6180_ALS_READY BIT(5)
62#define VL6180_RANGE_READY BIT(2)
63
64/* bits of the INTR_CLEAR register */
65#define VL6180_CLEAR_ERROR BIT(2)
66#define VL6180_CLEAR_ALS BIT(1)
67#define VL6180_CLEAR_RANGE BIT(0)
68
69/* bits of the HOLD register */
70#define VL6180_HOLD_ON BIT(0)
71
72/* default value for the ALS_IT register */
73#define VL6180_ALS_IT_100 0x63 /* 100 ms */
74
75/* values for the ALS_GAIN register */
76#define VL6180_ALS_GAIN_1 0x46
77#define VL6180_ALS_GAIN_1_25 0x45
78#define VL6180_ALS_GAIN_1_67 0x44
79#define VL6180_ALS_GAIN_2_5 0x43
80#define VL6180_ALS_GAIN_5 0x42
81#define VL6180_ALS_GAIN_10 0x41
82#define VL6180_ALS_GAIN_20 0x40
83#define VL6180_ALS_GAIN_40 0x47
84
85struct vl6180_data {
86 struct i2c_client *client;
87 struct mutex lock;
88 unsigned int als_gain_milli;
89 unsigned int als_it_ms;
90};
91
92enum { VL6180_ALS, VL6180_RANGE, VL6180_PROX };
93
94/**
95 * struct vl6180_chan_regs - Registers for accessing channels
96 * @drdy_mask: Data ready bit in status register
97 * @start_reg: Conversion start register
98 * @value_reg: Result value register
99 * @word: Register word length
100 */
101struct vl6180_chan_regs {
102 u8 drdy_mask;
103 u16 start_reg, value_reg;
104 bool word;
105};
106
107static const struct vl6180_chan_regs vl6180_chan_regs_table[] = {
108 [VL6180_ALS] = {
109 .drdy_mask = VL6180_ALS_READY,
110 .start_reg = VL6180_ALS_START,
111 .value_reg = VL6180_ALS_VALUE,
112 .word = true,
113 },
114 [VL6180_RANGE] = {
115 .drdy_mask = VL6180_RANGE_READY,
116 .start_reg = VL6180_RANGE_START,
117 .value_reg = VL6180_RANGE_VALUE,
118 .word = false,
119 },
120 [VL6180_PROX] = {
121 .drdy_mask = VL6180_RANGE_READY,
122 .start_reg = VL6180_RANGE_START,
123 .value_reg = VL6180_RANGE_RATE,
124 .word = true,
125 },
126};
127
128static int vl6180_read(struct i2c_client *client, u16 cmd, void *databuf,
129 u8 len)
130{
131 __be16 cmdbuf = cpu_to_be16(cmd);
132 struct i2c_msg msgs[2] = {
133 { .addr = client->addr, .len = sizeof(cmdbuf), .buf = (u8 *) &cmdbuf },
134 { .addr = client->addr, .len = len, .buf = databuf,
135 .flags = I2C_M_RD } };
136 int ret;
137
138 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
139 if (ret < 0)
140 dev_err(&client->dev, "failed reading register 0x%04x\n", cmd);
141
142 return ret;
143}
144
145static int vl6180_read_byte(struct i2c_client *client, u16 cmd)
146{
147 u8 data;
148 int ret;
149
150 ret = vl6180_read(client, cmd, &data, sizeof(data));
151 if (ret < 0)
152 return ret;
153
154 return data;
155}
156
157static int vl6180_read_word(struct i2c_client *client, u16 cmd)
158{
159 __be16 data;
160 int ret;
161
162 ret = vl6180_read(client, cmd, &data, sizeof(data));
163 if (ret < 0)
164 return ret;
165
166 return be16_to_cpu(data);
167}
168
169static int vl6180_write_byte(struct i2c_client *client, u16 cmd, u8 val)
170{
171 u8 buf[3];
172 struct i2c_msg msgs[1] = {
173 { .addr = client->addr, .len = sizeof(buf), .buf = (u8 *) &buf } };
174 int ret;
175
176 buf[0] = cmd >> 8;
177 buf[1] = cmd & 0xff;
178 buf[2] = val;
179
180 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
181 if (ret < 0) {
182 dev_err(&client->dev, "failed writing register 0x%04x\n", cmd);
183 return ret;
184 }
185
186 return 0;
187}
188
189static int vl6180_write_word(struct i2c_client *client, u16 cmd, u16 val)
190{
191 __be16 buf[2];
192 struct i2c_msg msgs[1] = {
193 { .addr = client->addr, .len = sizeof(buf), .buf = (u8 *) &buf } };
194 int ret;
195
196 buf[0] = cpu_to_be16(cmd);
197 buf[1] = cpu_to_be16(val);
198
199 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
200 if (ret < 0) {
201 dev_err(&client->dev, "failed writing register 0x%04x\n", cmd);
202 return ret;
203 }
204
205 return 0;
206}
207
208static int vl6180_measure(struct vl6180_data *data, int addr)
209{
210 struct i2c_client *client = data->client;
211 int tries = 20, ret;
212 u16 value;
213
214 mutex_lock(&data->lock);
215 /* Start single shot measurement */
216 ret = vl6180_write_byte(client,
217 vl6180_chan_regs_table[addr].start_reg, VL6180_STARTSTOP);
218 if (ret < 0)
219 goto fail;
220
221 while (tries--) {
222 ret = vl6180_read_byte(client, VL6180_INTR_STATUS);
223 if (ret < 0)
224 goto fail;
225
226 if (ret & vl6180_chan_regs_table[addr].drdy_mask)
227 break;
228 msleep(20);
229 }
230
231 if (tries < 0) {
232 ret = -EIO;
233 goto fail;
234 }
235
236 /* Read result value from appropriate registers */
237 ret = vl6180_chan_regs_table[addr].word ?
238 vl6180_read_word(client, vl6180_chan_regs_table[addr].value_reg) :
239 vl6180_read_byte(client, vl6180_chan_regs_table[addr].value_reg);
240 if (ret < 0)
241 goto fail;
242 value = ret;
243
244 /* Clear the interrupt flag after data read */
245 ret = vl6180_write_byte(client, VL6180_INTR_CLEAR,
246 VL6180_CLEAR_ERROR | VL6180_CLEAR_ALS | VL6180_CLEAR_RANGE);
247 if (ret < 0)
248 goto fail;
249
250 ret = value;
251
252fail:
253 mutex_unlock(&data->lock);
254
255 return ret;
256}
257
258static const struct iio_chan_spec vl6180_channels[] = {
259 {
260 .type = IIO_LIGHT,
261 .address = VL6180_ALS,
262 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
263 BIT(IIO_CHAN_INFO_INT_TIME) |
264 BIT(IIO_CHAN_INFO_SCALE) |
265 BIT(IIO_CHAN_INFO_HARDWAREGAIN),
266 }, {
267 .type = IIO_DISTANCE,
268 .address = VL6180_RANGE,
269 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
270 BIT(IIO_CHAN_INFO_SCALE),
271 }, {
272 .type = IIO_PROXIMITY,
273 .address = VL6180_PROX,
274 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
275 }
276};
277
278/*
279 * Available Ambient Light Sensor gain settings, 1/1000th, and
280 * corresponding setting for the VL6180_ALS_GAIN register
281 */
282static const int vl6180_als_gain_tab[8] = {
283 1000, 1250, 1670, 2500, 5000, 10000, 20000, 40000
284};
285static const u8 vl6180_als_gain_tab_bits[8] = {
286 VL6180_ALS_GAIN_1, VL6180_ALS_GAIN_1_25,
287 VL6180_ALS_GAIN_1_67, VL6180_ALS_GAIN_2_5,
288 VL6180_ALS_GAIN_5, VL6180_ALS_GAIN_10,
289 VL6180_ALS_GAIN_20, VL6180_ALS_GAIN_40
290};
291
292static int vl6180_read_raw(struct iio_dev *indio_dev,
293 struct iio_chan_spec const *chan,
294 int *val, int *val2, long mask)
295{
296 struct vl6180_data *data = iio_priv(indio_dev);
297 int ret;
298
299 switch (mask) {
300 case IIO_CHAN_INFO_RAW:
301 ret = vl6180_measure(data, chan->address);
302 if (ret < 0)
303 return ret;
304 *val = ret;
305
306 return IIO_VAL_INT;
307 case IIO_CHAN_INFO_INT_TIME:
308 *val = data->als_it_ms;
309 *val2 = 1000;
310
311 return IIO_VAL_FRACTIONAL;
312
313 case IIO_CHAN_INFO_SCALE:
314 switch (chan->type) {
315 case IIO_LIGHT:
316 /* one ALS count is 0.32 Lux @ gain 1, IT 100 ms */
317 *val = 32000; /* 0.32 * 1000 * 100 */
318 *val2 = data->als_gain_milli * data->als_it_ms;
319
320 return IIO_VAL_FRACTIONAL;
321
322 case IIO_DISTANCE:
323 *val = 0; /* sensor reports mm, scale to meter */
324 *val2 = 1000;
325 break;
326 default:
327 return -EINVAL;
328 }
329
330 return IIO_VAL_INT_PLUS_MICRO;
331 case IIO_CHAN_INFO_HARDWAREGAIN:
332 *val = data->als_gain_milli;
333 *val2 = 1000;
334
335 return IIO_VAL_FRACTIONAL;
336
337 default:
338 return -EINVAL;
339 }
340}
341
342static IIO_CONST_ATTR(als_gain_available, "1 1.25 1.67 2.5 5 10 20 40");
343
344static struct attribute *vl6180_attributes[] = {
345 &iio_const_attr_als_gain_available.dev_attr.attr,
346 NULL
347};
348
349static const struct attribute_group vl6180_attribute_group = {
350 .attrs = vl6180_attributes,
351};
352
353/* HOLD is needed before updating any config registers */
354static int vl6180_hold(struct vl6180_data *data, bool hold)
355{
356 return vl6180_write_byte(data->client, VL6180_HOLD,
357 hold ? VL6180_HOLD_ON : 0);
358}
359
360static int vl6180_set_als_gain(struct vl6180_data *data, int val, int val2)
361{
362 int i, ret, gain;
363
364 if (val < 1 || val > 40)
365 return -EINVAL;
366
367 gain = (val * 1000000 + val2) / 1000;
368 if (gain < 1 || gain > 40000)
369 return -EINVAL;
370
371 i = find_closest(gain, vl6180_als_gain_tab,
372 ARRAY_SIZE(vl6180_als_gain_tab));
373
374 mutex_lock(&data->lock);
375 ret = vl6180_hold(data, true);
376 if (ret < 0)
377 goto fail;
378
379 ret = vl6180_write_byte(data->client, VL6180_ALS_GAIN,
380 vl6180_als_gain_tab_bits[i]);
381
382 if (ret >= 0)
383 data->als_gain_milli = vl6180_als_gain_tab[i];
384
385fail:
386 vl6180_hold(data, false);
387 mutex_unlock(&data->lock);
388 return ret;
389}
390
391static int vl6180_set_it(struct vl6180_data *data, int val, int val2)
392{
393 int ret, it_ms;
394
395 it_ms = DIV_ROUND_CLOSEST(val2, 1000); /* round to ms */
396 if (val != 0 || it_ms < 1 || it_ms > 512)
397 return -EINVAL;
398
399 mutex_lock(&data->lock);
400 ret = vl6180_hold(data, true);
401 if (ret < 0)
402 goto fail;
403
404 ret = vl6180_write_word(data->client, VL6180_ALS_IT, it_ms - 1);
405
406 if (ret >= 0)
407 data->als_it_ms = it_ms;
408
409fail:
410 vl6180_hold(data, false);
411 mutex_unlock(&data->lock);
412
413 return ret;
414}
415
416static int vl6180_write_raw(struct iio_dev *indio_dev,
417 struct iio_chan_spec const *chan,
418 int val, int val2, long mask)
419{
420 struct vl6180_data *data = iio_priv(indio_dev);
421
422 switch (mask) {
423 case IIO_CHAN_INFO_INT_TIME:
424 return vl6180_set_it(data, val, val2);
425
426 case IIO_CHAN_INFO_HARDWAREGAIN:
427 if (chan->type != IIO_LIGHT)
428 return -EINVAL;
429
430 return vl6180_set_als_gain(data, val, val2);
431 default:
432 return -EINVAL;
433 }
434}
435
436static const struct iio_info vl6180_info = {
437 .read_raw = vl6180_read_raw,
438 .write_raw = vl6180_write_raw,
439 .attrs = &vl6180_attribute_group,
440};
441
442static int vl6180_init(struct vl6180_data *data)
443{
444 struct i2c_client *client = data->client;
445 int ret;
446
447 ret = vl6180_read_byte(client, VL6180_MODEL_ID);
448 if (ret < 0)
449 return ret;
450
451 if (ret != VL6180_MODEL_ID_VAL) {
452 dev_err(&client->dev, "invalid model ID %02x\n", ret);
453 return -ENODEV;
454 }
455
456 ret = vl6180_hold(data, true);
457 if (ret < 0)
458 return ret;
459
460 ret = vl6180_read_byte(client, VL6180_OUT_OF_RESET);
461 if (ret < 0)
462 return ret;
463
464 /*
465 * Detect false reset condition here. This bit is always set when the
466 * system comes out of reset.
467 */
468 if (ret != 0x01)
469 dev_info(&client->dev, "device is not fresh out of reset\n");
470
471 /* Enable ALS and Range ready interrupts */
472 ret = vl6180_write_byte(client, VL6180_INTR_CONFIG,
473 VL6180_ALS_READY | VL6180_RANGE_READY);
474 if (ret < 0)
475 return ret;
476
477 /* ALS integration time: 100ms */
478 data->als_it_ms = 100;
479 ret = vl6180_write_word(client, VL6180_ALS_IT, VL6180_ALS_IT_100);
480 if (ret < 0)
481 return ret;
482
483 /* ALS gain: 1 */
484 data->als_gain_milli = 1000;
485 ret = vl6180_write_byte(client, VL6180_ALS_GAIN, VL6180_ALS_GAIN_1);
486 if (ret < 0)
487 return ret;
488
489 ret = vl6180_write_byte(client, VL6180_OUT_OF_RESET, 0x00);
490 if (ret < 0)
491 return ret;
492
493 return vl6180_hold(data, false);
494}
495
496static int vl6180_probe(struct i2c_client *client,
497 const struct i2c_device_id *id)
498{
499 struct vl6180_data *data;
500 struct iio_dev *indio_dev;
501 int ret;
502
503 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
504 if (!indio_dev)
505 return -ENOMEM;
506
507 data = iio_priv(indio_dev);
508 i2c_set_clientdata(client, indio_dev);
509 data->client = client;
510 mutex_init(&data->lock);
511
512 indio_dev->info = &vl6180_info;
513 indio_dev->channels = vl6180_channels;
514 indio_dev->num_channels = ARRAY_SIZE(vl6180_channels);
515 indio_dev->name = VL6180_DRV_NAME;
516 indio_dev->modes = INDIO_DIRECT_MODE;
517
518 ret = vl6180_init(data);
519 if (ret < 0)
520 return ret;
521
522 return devm_iio_device_register(&client->dev, indio_dev);
523}
524
525static const struct of_device_id vl6180_of_match[] = {
526 { .compatible = "st,vl6180", },
527 { },
528};
529MODULE_DEVICE_TABLE(of, vl6180_of_match);
530
531static const struct i2c_device_id vl6180_id[] = {
532 { "vl6180", 0 },
533 { }
534};
535MODULE_DEVICE_TABLE(i2c, vl6180_id);
536
537static struct i2c_driver vl6180_driver = {
538 .driver = {
539 .name = VL6180_DRV_NAME,
540 .of_match_table = vl6180_of_match,
541 },
542 .probe = vl6180_probe,
543 .id_table = vl6180_id,
544};
545
546module_i2c_driver(vl6180_driver);
547
548MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>");
549MODULE_AUTHOR("Manivannan Sadhasivam <manivannanece23@gmail.com>");
550MODULE_DESCRIPTION("STMicro VL6180 ALS, range and proximity sensor driver");
551MODULE_LICENSE("GPL");