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/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 | |
84 | struct 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 | |
91 | enum { 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 | */ |
100 | struct vl6180_chan_regs { |
101 | u8 drdy_mask; |
102 | u16 start_reg, value_reg; |
103 | bool word; |
104 | }; |
105 | |
106 | static 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 | |
127 | static 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(adap: 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 | |
144 | static int vl6180_read_byte(struct i2c_client *client, u16 cmd) |
145 | { |
146 | u8 data; |
147 | int ret; |
148 | |
149 | ret = vl6180_read(client, cmd, databuf: &data, len: sizeof(data)); |
150 | if (ret < 0) |
151 | return ret; |
152 | |
153 | return data; |
154 | } |
155 | |
156 | static int vl6180_read_word(struct i2c_client *client, u16 cmd) |
157 | { |
158 | __be16 data; |
159 | int ret; |
160 | |
161 | ret = vl6180_read(client, cmd, databuf: &data, len: sizeof(data)); |
162 | if (ret < 0) |
163 | return ret; |
164 | |
165 | return be16_to_cpu(data); |
166 | } |
167 | |
168 | static 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(adap: 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 | |
188 | static 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(adap: 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 | |
207 | static 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 | cmd: 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(msecs: 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, cmd: vl6180_chan_regs_table[addr].value_reg) : |
238 | vl6180_read_byte(client, cmd: 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 | |
251 | fail: |
252 | mutex_unlock(lock: &data->lock); |
253 | |
254 | return ret; |
255 | } |
256 | |
257 | static 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 | */ |
281 | static const int vl6180_als_gain_tab[8] = { |
282 | 1000, 1250, 1670, 2500, 5000, 10000, 20000, 40000 |
283 | }; |
284 | static 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 | |
291 | static 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, addr: 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 | |
341 | static IIO_CONST_ATTR(als_gain_available, "1 1.25 1.67 2.5 5 10 20 40" ); |
342 | |
343 | static struct attribute *vl6180_attributes[] = { |
344 | &iio_const_attr_als_gain_available.dev_attr.attr, |
345 | NULL |
346 | }; |
347 | |
348 | static const struct attribute_group vl6180_attribute_group = { |
349 | .attrs = vl6180_attributes, |
350 | }; |
351 | |
352 | /* HOLD is needed before updating any config registers */ |
353 | static int vl6180_hold(struct vl6180_data *data, bool hold) |
354 | { |
355 | return vl6180_write_byte(client: data->client, VL6180_HOLD, |
356 | val: hold ? VL6180_HOLD_ON : 0); |
357 | } |
358 | |
359 | static 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, hold: true); |
375 | if (ret < 0) |
376 | goto fail; |
377 | |
378 | ret = vl6180_write_byte(client: data->client, VL6180_ALS_GAIN, |
379 | val: vl6180_als_gain_tab_bits[i]); |
380 | |
381 | if (ret >= 0) |
382 | data->als_gain_milli = vl6180_als_gain_tab[i]; |
383 | |
384 | fail: |
385 | vl6180_hold(data, hold: false); |
386 | mutex_unlock(lock: &data->lock); |
387 | return ret; |
388 | } |
389 | |
390 | static int vl6180_set_it(struct vl6180_data *data, int val, int val2) |
391 | { |
392 | int ret, it_ms; |
393 | |
394 | it_ms = DIV_ROUND_CLOSEST(val2, 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, hold: true); |
400 | if (ret < 0) |
401 | goto fail; |
402 | |
403 | ret = vl6180_write_word(client: data->client, VL6180_ALS_IT, val: it_ms - 1); |
404 | |
405 | if (ret >= 0) |
406 | data->als_it_ms = it_ms; |
407 | |
408 | fail: |
409 | vl6180_hold(data, hold: false); |
410 | mutex_unlock(lock: &data->lock); |
411 | |
412 | return ret; |
413 | } |
414 | |
415 | static 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 | |
435 | static 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 | |
441 | static 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, hold: 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, val: 0x00); |
489 | if (ret < 0) |
490 | return ret; |
491 | |
492 | return vl6180_hold(data, hold: false); |
493 | } |
494 | |
495 | static int vl6180_probe(struct i2c_client *client) |
496 | { |
497 | struct vl6180_data *data; |
498 | struct iio_dev *indio_dev; |
499 | int ret; |
500 | |
501 | indio_dev = devm_iio_device_alloc(parent: &client->dev, sizeof_priv: sizeof(*data)); |
502 | if (!indio_dev) |
503 | return -ENOMEM; |
504 | |
505 | data = iio_priv(indio_dev); |
506 | i2c_set_clientdata(client, data: indio_dev); |
507 | data->client = client; |
508 | mutex_init(&data->lock); |
509 | |
510 | indio_dev->info = &vl6180_info; |
511 | indio_dev->channels = vl6180_channels; |
512 | indio_dev->num_channels = ARRAY_SIZE(vl6180_channels); |
513 | indio_dev->name = VL6180_DRV_NAME; |
514 | indio_dev->modes = INDIO_DIRECT_MODE; |
515 | |
516 | ret = vl6180_init(data); |
517 | if (ret < 0) |
518 | return ret; |
519 | |
520 | return devm_iio_device_register(&client->dev, indio_dev); |
521 | } |
522 | |
523 | static const struct of_device_id vl6180_of_match[] = { |
524 | { .compatible = "st,vl6180" , }, |
525 | { }, |
526 | }; |
527 | MODULE_DEVICE_TABLE(of, vl6180_of_match); |
528 | |
529 | static const struct i2c_device_id vl6180_id[] = { |
530 | { "vl6180" , 0 }, |
531 | { } |
532 | }; |
533 | MODULE_DEVICE_TABLE(i2c, vl6180_id); |
534 | |
535 | static struct i2c_driver vl6180_driver = { |
536 | .driver = { |
537 | .name = VL6180_DRV_NAME, |
538 | .of_match_table = vl6180_of_match, |
539 | }, |
540 | .probe = vl6180_probe, |
541 | .id_table = vl6180_id, |
542 | }; |
543 | |
544 | module_i2c_driver(vl6180_driver); |
545 | |
546 | MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>" ); |
547 | MODULE_AUTHOR("Manivannan Sadhasivam <manivannanece23@gmail.com>" ); |
548 | MODULE_DESCRIPTION("STMicro VL6180 ALS, range and proximity sensor driver" ); |
549 | MODULE_LICENSE("GPL" ); |
550 | |