1 /*
2  * STMicroelectronics st_lsm6dsx i2c controller driver
3  *
4  * i2c controller embedded in lsm6dx series can connect up to four
5  * slave devices using accelerometer sensor as trigger for i2c
6  * read/write operations. Current implementation relies on SLV0 channel
7  * for slave configuration and SLV{1,2,3} to read data and push them into
8  * the hw FIFO
9  *
10  * Copyright (C) 2018 Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
11  *
12  * Permission to use, copy, modify, and/or distribute this software for any
13  * purpose with or without fee is hereby granted, provided that the above
14  * copyright notice and this permission notice appear in all copies.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
17  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
18  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
19  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
20  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
21  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
22  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
23  *
24  */
25 #include <linux/module.h>
26 #include <linux/regmap.h>
27 #include <linux/iio/iio.h>
28 #include <linux/iio/sysfs.h>
29 #include <linux/bitfield.h>
30 
31 #include "st_lsm6dsx.h"
32 
33 #define ST_LSM6DSX_MAX_SLV_NUM			3
34 #define ST_LSM6DSX_SLV_ADDR(n, base)		((base) + (n) * 3)
35 #define ST_LSM6DSX_SLV_SUB_ADDR(n, base)	((base) + 1 + (n) * 3)
36 #define ST_LSM6DSX_SLV_CONFIG(n, base)		((base) + 2 + (n) * 3)
37 
38 #define ST_LS6DSX_READ_OP_MASK			GENMASK(2, 0)
39 
40 static const struct st_lsm6dsx_ext_dev_settings st_lsm6dsx_ext_dev_table[] = {
41 	/* LIS2MDL */
42 	{
43 		.i2c_addr = { 0x1e },
44 		.wai = {
45 			.addr = 0x4f,
46 			.val = 0x40,
47 		},
48 		.id = ST_LSM6DSX_ID_MAGN,
49 		.odr_table = {
50 			.reg = {
51 				.addr = 0x60,
52 				.mask = GENMASK(3, 2),
53 			},
54 			.odr_avl[0] = {  10, 0x0 },
55 			.odr_avl[1] = {  20, 0x1 },
56 			.odr_avl[2] = {  50, 0x2 },
57 			.odr_avl[3] = { 100, 0x3 },
58 		},
59 		.fs_table = {
60 			.fs_avl[0] = {
61 				.gain = 1500,
62 				.val = 0x0,
63 			}, /* 1500 uG/LSB */
64 		},
65 		.temp_comp = {
66 			.addr = 0x60,
67 			.mask = BIT(7),
68 		},
69 		.pwr_table = {
70 			.reg = {
71 				.addr = 0x60,
72 				.mask = GENMASK(1, 0),
73 			},
74 			.off_val = 0x2,
75 			.on_val = 0x0,
76 		},
77 		.off_canc = {
78 			.addr = 0x61,
79 			.mask = BIT(1),
80 		},
81 		.bdu = {
82 			.addr = 0x62,
83 			.mask = BIT(4),
84 		},
85 		.out = {
86 			.addr = 0x68,
87 			.len = 6,
88 		},
89 	},
90 };
91 
92 static void st_lsm6dsx_shub_wait_complete(struct st_lsm6dsx_hw *hw)
93 {
94 	struct st_lsm6dsx_sensor *sensor;
95 
96 	sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
97 	msleep((2000U / sensor->odr) + 1);
98 }
99 
100 /**
101  * st_lsm6dsx_shub_read_reg - read i2c controller register
102  *
103  * Read st_lsm6dsx i2c controller register
104  */
105 static int st_lsm6dsx_shub_read_reg(struct st_lsm6dsx_hw *hw, u8 addr,
106 				    u8 *data, int len)
107 {
108 	const struct st_lsm6dsx_shub_settings *hub_settings;
109 	int err;
110 
111 	mutex_lock(&hw->page_lock);
112 
113 	hub_settings = &hw->settings->shub_settings;
114 	err = st_lsm6dsx_set_page(hw, true);
115 	if (err < 0)
116 		goto out;
117 
118 	err = regmap_bulk_read(hw->regmap, addr, data, len);
119 
120 	st_lsm6dsx_set_page(hw, false);
121 out:
122 	mutex_unlock(&hw->page_lock);
123 
124 	return err;
125 }
126 
127 /**
128  * st_lsm6dsx_shub_write_reg - write i2c controller register
129  *
130  * Write st_lsm6dsx i2c controller register
131  */
132 static int st_lsm6dsx_shub_write_reg(struct st_lsm6dsx_hw *hw, u8 addr,
133 				     u8 *data, int len)
134 {
135 	int err;
136 
137 	mutex_lock(&hw->page_lock);
138 	err = st_lsm6dsx_set_page(hw, true);
139 	if (err < 0)
140 		goto out;
141 
142 	err = regmap_bulk_write(hw->regmap, addr, data, len);
143 
144 	st_lsm6dsx_set_page(hw, false);
145 out:
146 	mutex_unlock(&hw->page_lock);
147 
148 	return err;
149 }
150 
151 static int
152 st_lsm6dsx_shub_write_reg_with_mask(struct st_lsm6dsx_hw *hw, u8 addr,
153 				    u8 mask, u8 val)
154 {
155 	int err;
156 
157 	mutex_lock(&hw->page_lock);
158 	err = st_lsm6dsx_set_page(hw, true);
159 	if (err < 0)
160 		goto out;
161 
162 	err = regmap_update_bits(hw->regmap, addr, mask, val);
163 
164 	st_lsm6dsx_set_page(hw, false);
165 out:
166 	mutex_unlock(&hw->page_lock);
167 
168 	return err;
169 }
170 
171 static int st_lsm6dsx_shub_master_enable(struct st_lsm6dsx_sensor *sensor,
172 					 bool enable)
173 {
174 	const struct st_lsm6dsx_shub_settings *hub_settings;
175 	struct st_lsm6dsx_hw *hw = sensor->hw;
176 	unsigned int data;
177 	int err;
178 
179 	/* enable acc sensor as trigger */
180 	err = st_lsm6dsx_sensor_set_enable(sensor, enable);
181 	if (err < 0)
182 		return err;
183 
184 	mutex_lock(&hw->page_lock);
185 
186 	hub_settings = &hw->settings->shub_settings;
187 	err = st_lsm6dsx_set_page(hw, true);
188 	if (err < 0)
189 		goto out;
190 
191 	data = ST_LSM6DSX_SHIFT_VAL(enable, hub_settings->master_en.mask);
192 	err = regmap_update_bits(hw->regmap, hub_settings->master_en.addr,
193 				 hub_settings->master_en.mask, data);
194 
195 	st_lsm6dsx_set_page(hw, false);
196 out:
197 	mutex_unlock(&hw->page_lock);
198 
199 	return err;
200 }
201 
202 /**
203  * st_lsm6dsx_shub_read - read data from slave device register
204  *
205  * Read data from slave device register. SLV0 is used for
206  * one-shot read operation
207  */
208 static int
209 st_lsm6dsx_shub_read(struct st_lsm6dsx_sensor *sensor, u8 addr,
210 		     u8 *data, int len)
211 {
212 	const struct st_lsm6dsx_shub_settings *hub_settings;
213 	struct st_lsm6dsx_hw *hw = sensor->hw;
214 	u8 config[3], slv_addr;
215 	int err;
216 
217 	hub_settings = &hw->settings->shub_settings;
218 	slv_addr = ST_LSM6DSX_SLV_ADDR(0, hub_settings->slv0_addr);
219 
220 	config[0] = (sensor->ext_info.addr << 1) | 1;
221 	config[1] = addr;
222 	config[2] = len & ST_LS6DSX_READ_OP_MASK;
223 
224 	err = st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
225 					sizeof(config));
226 	if (err < 0)
227 		return err;
228 
229 	err = st_lsm6dsx_shub_master_enable(sensor, true);
230 	if (err < 0)
231 		return err;
232 
233 	st_lsm6dsx_shub_wait_complete(hw);
234 
235 	err = st_lsm6dsx_shub_read_reg(hw, hub_settings->shub_out, data,
236 				       len & ST_LS6DSX_READ_OP_MASK);
237 
238 	st_lsm6dsx_shub_master_enable(sensor, false);
239 
240 	memset(config, 0, sizeof(config));
241 	return st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
242 					 sizeof(config));
243 }
244 
245 /**
246  * st_lsm6dsx_shub_write - write data to slave device register
247  *
248  * Write data from slave device register. SLV0 is used for
249  * one-shot write operation
250  */
251 static int
252 st_lsm6dsx_shub_write(struct st_lsm6dsx_sensor *sensor, u8 addr,
253 		      u8 *data, int len)
254 {
255 	const struct st_lsm6dsx_shub_settings *hub_settings;
256 	struct st_lsm6dsx_hw *hw = sensor->hw;
257 	u8 config[2], slv_addr;
258 	int err, i;
259 
260 	hub_settings = &hw->settings->shub_settings;
261 	if (hub_settings->wr_once.addr) {
262 		unsigned int data;
263 
264 		data = ST_LSM6DSX_SHIFT_VAL(1, hub_settings->wr_once.mask);
265 		err = st_lsm6dsx_shub_write_reg_with_mask(hw,
266 			hub_settings->wr_once.addr,
267 			hub_settings->wr_once.mask,
268 			data);
269 		if (err < 0)
270 			return err;
271 	}
272 
273 	slv_addr = ST_LSM6DSX_SLV_ADDR(0, hub_settings->slv0_addr);
274 	config[0] = sensor->ext_info.addr << 1;
275 	for (i = 0 ; i < len; i++) {
276 		config[1] = addr + i;
277 
278 		err = st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
279 						sizeof(config));
280 		if (err < 0)
281 			return err;
282 
283 		err = st_lsm6dsx_shub_write_reg(hw, hub_settings->dw_slv0_addr,
284 						&data[i], 1);
285 		if (err < 0)
286 			return err;
287 
288 		err = st_lsm6dsx_shub_master_enable(sensor, true);
289 		if (err < 0)
290 			return err;
291 
292 		st_lsm6dsx_shub_wait_complete(hw);
293 
294 		st_lsm6dsx_shub_master_enable(sensor, false);
295 	}
296 
297 	memset(config, 0, sizeof(config));
298 	return st_lsm6dsx_shub_write_reg(hw, slv_addr, config, sizeof(config));
299 }
300 
301 static int
302 st_lsm6dsx_shub_write_with_mask(struct st_lsm6dsx_sensor *sensor,
303 				u8 addr, u8 mask, u8 val)
304 {
305 	int err;
306 	u8 data;
307 
308 	err = st_lsm6dsx_shub_read(sensor, addr, &data, sizeof(data));
309 	if (err < 0)
310 		return err;
311 
312 	data = ((data & ~mask) | (val << __ffs(mask) & mask));
313 
314 	return st_lsm6dsx_shub_write(sensor, addr, &data, sizeof(data));
315 }
316 
317 static int
318 st_lsm6dsx_shub_get_odr_val(struct st_lsm6dsx_sensor *sensor,
319 			    u16 odr, u16 *val)
320 {
321 	const struct st_lsm6dsx_ext_dev_settings *settings;
322 	int i;
323 
324 	settings = sensor->ext_info.settings;
325 	for (i = 0; i < ST_LSM6DSX_ODR_LIST_SIZE; i++)
326 		if (settings->odr_table.odr_avl[i].hz == odr)
327 			break;
328 
329 	if (i == ST_LSM6DSX_ODR_LIST_SIZE)
330 		return -EINVAL;
331 
332 	*val = settings->odr_table.odr_avl[i].val;
333 	return 0;
334 }
335 
336 static int
337 st_lsm6dsx_shub_set_odr(struct st_lsm6dsx_sensor *sensor, u16 odr)
338 {
339 	const struct st_lsm6dsx_ext_dev_settings *settings;
340 	u16 val;
341 	int err;
342 
343 	err = st_lsm6dsx_shub_get_odr_val(sensor, odr, &val);
344 	if (err < 0)
345 		return err;
346 
347 	settings = sensor->ext_info.settings;
348 	return st_lsm6dsx_shub_write_with_mask(sensor,
349 					       settings->odr_table.reg.addr,
350 					       settings->odr_table.reg.mask,
351 					       val);
352 }
353 
354 /* use SLV{1,2,3} for FIFO read operations */
355 static int
356 st_lsm6dsx_shub_config_channels(struct st_lsm6dsx_sensor *sensor,
357 				bool enable)
358 {
359 	const struct st_lsm6dsx_shub_settings *hub_settings;
360 	const struct st_lsm6dsx_ext_dev_settings *settings;
361 	u8 config[9] = {}, enable_mask, slv_addr;
362 	struct st_lsm6dsx_hw *hw = sensor->hw;
363 	struct st_lsm6dsx_sensor *cur_sensor;
364 	int i, j = 0;
365 
366 	hub_settings = &hw->settings->shub_settings;
367 	if (enable)
368 		enable_mask = hw->enable_mask | BIT(sensor->id);
369 	else
370 		enable_mask = hw->enable_mask & ~BIT(sensor->id);
371 
372 	for (i = ST_LSM6DSX_ID_EXT0; i <= ST_LSM6DSX_ID_EXT2; i++) {
373 		if (!hw->iio_devs[i])
374 			continue;
375 
376 		cur_sensor = iio_priv(hw->iio_devs[i]);
377 		if (!(enable_mask & BIT(cur_sensor->id)))
378 			continue;
379 
380 		settings = cur_sensor->ext_info.settings;
381 		config[j] = (sensor->ext_info.addr << 1) | 1;
382 		config[j + 1] = settings->out.addr;
383 		config[j + 2] = (settings->out.len & ST_LS6DSX_READ_OP_MASK) |
384 				hub_settings->batch_en;
385 		j += 3;
386 	}
387 
388 	slv_addr = ST_LSM6DSX_SLV_ADDR(1, hub_settings->slv0_addr);
389 	return st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
390 					 sizeof(config));
391 }
392 
393 int st_lsm6dsx_shub_set_enable(struct st_lsm6dsx_sensor *sensor, bool enable)
394 {
395 	const struct st_lsm6dsx_ext_dev_settings *settings;
396 	int err;
397 
398 	err = st_lsm6dsx_shub_config_channels(sensor, enable);
399 	if (err < 0)
400 		return err;
401 
402 	settings = sensor->ext_info.settings;
403 	if (enable) {
404 		err = st_lsm6dsx_shub_set_odr(sensor, sensor->odr);
405 		if (err < 0)
406 			return err;
407 	} else {
408 		err = st_lsm6dsx_shub_write_with_mask(sensor,
409 					settings->odr_table.reg.addr,
410 					settings->odr_table.reg.mask, 0);
411 		if (err < 0)
412 			return err;
413 	}
414 
415 	if (settings->pwr_table.reg.addr) {
416 		u8 val;
417 
418 		val = enable ? settings->pwr_table.on_val
419 			     : settings->pwr_table.off_val;
420 		err = st_lsm6dsx_shub_write_with_mask(sensor,
421 					settings->pwr_table.reg.addr,
422 					settings->pwr_table.reg.mask, val);
423 		if (err < 0)
424 			return err;
425 	}
426 
427 	return st_lsm6dsx_shub_master_enable(sensor, enable);
428 }
429 
430 static int
431 st_lsm6dsx_shub_read_oneshot(struct st_lsm6dsx_sensor *sensor,
432 			     struct iio_chan_spec const *ch,
433 			     int *val)
434 {
435 	int err, delay, len;
436 	u8 data[4];
437 
438 	err = st_lsm6dsx_shub_set_enable(sensor, true);
439 	if (err < 0)
440 		return err;
441 
442 	delay = 1000000 / sensor->odr;
443 	usleep_range(delay, 2 * delay);
444 
445 	len = min_t(int, sizeof(data), ch->scan_type.realbits >> 3);
446 	err = st_lsm6dsx_shub_read(sensor, ch->address, data, len);
447 
448 	st_lsm6dsx_shub_set_enable(sensor, false);
449 
450 	if (err < 0)
451 		return err;
452 
453 	switch (len) {
454 	case 2:
455 		*val = (s16)le16_to_cpu(*((__le16 *)data));
456 		break;
457 	default:
458 		return -EINVAL;
459 	}
460 
461 	return IIO_VAL_INT;
462 }
463 
464 static int
465 st_lsm6dsx_shub_read_raw(struct iio_dev *iio_dev,
466 			 struct iio_chan_spec const *ch,
467 			 int *val, int *val2, long mask)
468 {
469 	struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
470 	int ret;
471 
472 	switch (mask) {
473 	case IIO_CHAN_INFO_RAW:
474 		ret = iio_device_claim_direct_mode(iio_dev);
475 		if (ret)
476 			break;
477 
478 		ret = st_lsm6dsx_shub_read_oneshot(sensor, ch, val);
479 		iio_device_release_direct_mode(iio_dev);
480 		break;
481 	case IIO_CHAN_INFO_SAMP_FREQ:
482 		*val = sensor->odr;
483 		ret = IIO_VAL_INT;
484 		break;
485 	case IIO_CHAN_INFO_SCALE:
486 		*val = 0;
487 		*val2 = sensor->gain;
488 		ret = IIO_VAL_INT_PLUS_MICRO;
489 		break;
490 	default:
491 		ret = -EINVAL;
492 		break;
493 	}
494 
495 	return ret;
496 }
497 
498 static int
499 st_lsm6dsx_shub_write_raw(struct iio_dev *iio_dev,
500 			  struct iio_chan_spec const *chan,
501 			  int val, int val2, long mask)
502 {
503 	struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
504 	int err;
505 
506 	err = iio_device_claim_direct_mode(iio_dev);
507 	if (err)
508 		return err;
509 
510 	switch (mask) {
511 	case IIO_CHAN_INFO_SAMP_FREQ: {
512 		u16 data;
513 
514 		err = st_lsm6dsx_shub_get_odr_val(sensor, val, &data);
515 		if (!err)
516 			sensor->odr = val;
517 		break;
518 	}
519 	default:
520 		err = -EINVAL;
521 		break;
522 	}
523 
524 	iio_device_release_direct_mode(iio_dev);
525 
526 	return err;
527 }
528 
529 static ssize_t
530 st_lsm6dsx_shub_sampling_freq_avail(struct device *dev,
531 				    struct device_attribute *attr,
532 				    char *buf)
533 {
534 	struct st_lsm6dsx_sensor *sensor = iio_priv(dev_get_drvdata(dev));
535 	const struct st_lsm6dsx_ext_dev_settings *settings;
536 	int i, len = 0;
537 
538 	settings = sensor->ext_info.settings;
539 	for (i = 0; i < ST_LSM6DSX_ODR_LIST_SIZE; i++) {
540 		u16 val = settings->odr_table.odr_avl[i].hz;
541 
542 		if (val > 0)
543 			len += scnprintf(buf + len, PAGE_SIZE - len, "%d ",
544 					 val);
545 	}
546 	buf[len - 1] = '\n';
547 
548 	return len;
549 }
550 
551 static ssize_t st_lsm6dsx_shub_scale_avail(struct device *dev,
552 					   struct device_attribute *attr,
553 					   char *buf)
554 {
555 	struct st_lsm6dsx_sensor *sensor = iio_priv(dev_get_drvdata(dev));
556 	const struct st_lsm6dsx_ext_dev_settings *settings;
557 	int i, len = 0;
558 
559 	settings = sensor->ext_info.settings;
560 	for (i = 0; i < ST_LSM6DSX_FS_LIST_SIZE; i++) {
561 		u16 val = settings->fs_table.fs_avl[i].gain;
562 
563 		if (val > 0)
564 			len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06u ",
565 					 val);
566 	}
567 	buf[len - 1] = '\n';
568 
569 	return len;
570 }
571 
572 static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(st_lsm6dsx_shub_sampling_freq_avail);
573 static IIO_DEVICE_ATTR(in_scale_available, 0444,
574 		       st_lsm6dsx_shub_scale_avail, NULL, 0);
575 static struct attribute *st_lsm6dsx_ext_attributes[] = {
576 	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
577 	&iio_dev_attr_in_scale_available.dev_attr.attr,
578 	NULL,
579 };
580 
581 static const struct attribute_group st_lsm6dsx_ext_attribute_group = {
582 	.attrs = st_lsm6dsx_ext_attributes,
583 };
584 
585 static const struct iio_info st_lsm6dsx_ext_info = {
586 	.attrs = &st_lsm6dsx_ext_attribute_group,
587 	.read_raw = st_lsm6dsx_shub_read_raw,
588 	.write_raw = st_lsm6dsx_shub_write_raw,
589 	.hwfifo_set_watermark = st_lsm6dsx_set_watermark,
590 };
591 
592 static struct iio_dev *
593 st_lsm6dsx_shub_alloc_iiodev(struct st_lsm6dsx_hw *hw,
594 			     enum st_lsm6dsx_sensor_id id,
595 			     const struct st_lsm6dsx_ext_dev_settings *info,
596 			     u8 i2c_addr, const char *name)
597 {
598 	struct iio_chan_spec *ext_channels;
599 	struct st_lsm6dsx_sensor *sensor;
600 	struct iio_dev *iio_dev;
601 
602 	iio_dev = devm_iio_device_alloc(hw->dev, sizeof(*sensor));
603 	if (!iio_dev)
604 		return NULL;
605 
606 	iio_dev->modes = INDIO_DIRECT_MODE;
607 	iio_dev->dev.parent = hw->dev;
608 	iio_dev->info = &st_lsm6dsx_ext_info;
609 
610 	sensor = iio_priv(iio_dev);
611 	sensor->id = id;
612 	sensor->hw = hw;
613 	sensor->odr = info->odr_table.odr_avl[0].hz;
614 	sensor->gain = info->fs_table.fs_avl[0].gain;
615 	sensor->ext_info.settings = info;
616 	sensor->ext_info.addr = i2c_addr;
617 	sensor->watermark = 1;
618 
619 	switch (info->id) {
620 	case ST_LSM6DSX_ID_MAGN: {
621 		const struct iio_chan_spec magn_channels[] = {
622 			ST_LSM6DSX_CHANNEL(IIO_MAGN, info->out.addr,
623 					   IIO_MOD_X, 0),
624 			ST_LSM6DSX_CHANNEL(IIO_MAGN, info->out.addr + 2,
625 					   IIO_MOD_Y, 1),
626 			ST_LSM6DSX_CHANNEL(IIO_MAGN, info->out.addr + 4,
627 					   IIO_MOD_Z, 2),
628 			IIO_CHAN_SOFT_TIMESTAMP(3),
629 		};
630 
631 		ext_channels = devm_kzalloc(hw->dev, sizeof(magn_channels),
632 					    GFP_KERNEL);
633 		if (!ext_channels)
634 			return NULL;
635 
636 		memcpy(ext_channels, magn_channels, sizeof(magn_channels));
637 		iio_dev->available_scan_masks = st_lsm6dsx_available_scan_masks;
638 		iio_dev->channels = ext_channels;
639 		iio_dev->num_channels = ARRAY_SIZE(magn_channels);
640 
641 		scnprintf(sensor->name, sizeof(sensor->name), "%s_magn",
642 			  name);
643 		break;
644 	}
645 	default:
646 		return NULL;
647 	}
648 	iio_dev->name = sensor->name;
649 
650 	return iio_dev;
651 }
652 
653 static int st_lsm6dsx_shub_init_device(struct st_lsm6dsx_sensor *sensor)
654 {
655 	const struct st_lsm6dsx_ext_dev_settings *settings;
656 	int err;
657 
658 	settings = sensor->ext_info.settings;
659 	if (settings->bdu.addr) {
660 		err = st_lsm6dsx_shub_write_with_mask(sensor,
661 						      settings->bdu.addr,
662 						      settings->bdu.mask, 1);
663 		if (err < 0)
664 			return err;
665 	}
666 
667 	if (settings->temp_comp.addr) {
668 		err = st_lsm6dsx_shub_write_with_mask(sensor,
669 					settings->temp_comp.addr,
670 					settings->temp_comp.mask, 1);
671 		if (err < 0)
672 			return err;
673 	}
674 
675 	if (settings->off_canc.addr) {
676 		err = st_lsm6dsx_shub_write_with_mask(sensor,
677 					settings->off_canc.addr,
678 					settings->off_canc.mask, 1);
679 		if (err < 0)
680 			return err;
681 	}
682 
683 	return 0;
684 }
685 
686 static int
687 st_lsm6dsx_shub_check_wai(struct st_lsm6dsx_hw *hw, u8 *i2c_addr,
688 			  const struct st_lsm6dsx_ext_dev_settings *settings)
689 {
690 	const struct st_lsm6dsx_shub_settings *hub_settings;
691 	struct st_lsm6dsx_sensor *sensor;
692 	u8 config[3], data, slv_addr;
693 	bool found = false;
694 	int i, err;
695 
696 	hub_settings = &hw->settings->shub_settings;
697 	slv_addr = ST_LSM6DSX_SLV_ADDR(0, hub_settings->slv0_addr);
698 	sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
699 
700 	for (i = 0; i < ARRAY_SIZE(settings->i2c_addr); i++) {
701 		if (!settings->i2c_addr[i])
702 			continue;
703 
704 		/* read wai slave register */
705 		config[0] = (settings->i2c_addr[i] << 1) | 0x1;
706 		config[1] = settings->wai.addr;
707 		config[2] = 0x1;
708 
709 		err = st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
710 						sizeof(config));
711 		if (err < 0)
712 			return err;
713 
714 		err = st_lsm6dsx_shub_master_enable(sensor, true);
715 		if (err < 0)
716 			return err;
717 
718 		st_lsm6dsx_shub_wait_complete(hw);
719 
720 		err = st_lsm6dsx_shub_read_reg(hw,
721 					       hub_settings->shub_out,
722 					       &data, sizeof(data));
723 
724 		st_lsm6dsx_shub_master_enable(sensor, false);
725 
726 		if (err < 0)
727 			return err;
728 
729 		if (data != settings->wai.val)
730 			continue;
731 
732 		*i2c_addr = settings->i2c_addr[i];
733 		found = true;
734 		break;
735 	}
736 
737 	/* reset SLV0 channel */
738 	memset(config, 0, sizeof(config));
739 	err = st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
740 					sizeof(config));
741 	if (err < 0)
742 		return err;
743 
744 	return found ? 0 : -ENODEV;
745 }
746 
747 int st_lsm6dsx_shub_probe(struct st_lsm6dsx_hw *hw, const char *name)
748 {
749 	enum st_lsm6dsx_sensor_id id = ST_LSM6DSX_ID_EXT0;
750 	struct st_lsm6dsx_sensor *sensor;
751 	int err, i, num_ext_dev = 0;
752 	u8 i2c_addr = 0;
753 
754 	for (i = 0; i < ARRAY_SIZE(st_lsm6dsx_ext_dev_table); i++) {
755 		err = st_lsm6dsx_shub_check_wai(hw, &i2c_addr,
756 					&st_lsm6dsx_ext_dev_table[i]);
757 		if (err == -ENODEV)
758 			continue;
759 		else if (err < 0)
760 			return err;
761 
762 		hw->iio_devs[id] = st_lsm6dsx_shub_alloc_iiodev(hw, id,
763 						&st_lsm6dsx_ext_dev_table[i],
764 						i2c_addr, name);
765 		if (!hw->iio_devs[id])
766 			return -ENOMEM;
767 
768 		sensor = iio_priv(hw->iio_devs[id]);
769 		err = st_lsm6dsx_shub_init_device(sensor);
770 		if (err < 0)
771 			return err;
772 
773 		if (++num_ext_dev >= ST_LSM6DSX_MAX_SLV_NUM)
774 			break;
775 		id++;
776 	}
777 
778 	return 0;
779 }
780