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