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_SLV_ADDR(n, base)		((base) + (n) * 3)
34 #define ST_LSM6DSX_SLV_SUB_ADDR(n, base)	((base) + 1 + (n) * 3)
35 #define ST_LSM6DSX_SLV_CONFIG(n, base)		((base) + 2 + (n) * 3)
36 
37 #define ST_LS6DSX_READ_OP_MASK			GENMASK(2, 0)
38 
39 static const struct st_lsm6dsx_ext_dev_settings st_lsm6dsx_ext_dev_table[] = {
40 	/* LIS2MDL */
41 	{
42 		.i2c_addr = { 0x1e },
43 		.wai = {
44 			.addr = 0x4f,
45 			.val = 0x40,
46 		},
47 		.id = ST_LSM6DSX_ID_MAGN,
48 		.odr_table = {
49 			.reg = {
50 				.addr = 0x60,
51 				.mask = GENMASK(3, 2),
52 			},
53 			.odr_avl[0] = {  10000, 0x0 },
54 			.odr_avl[1] = {  20000, 0x1 },
55 			.odr_avl[2] = {  50000, 0x2 },
56 			.odr_avl[3] = { 100000, 0x3 },
57 			.odr_len = 4,
58 		},
59 		.fs_table = {
60 			.fs_avl[0] = {
61 				.gain = 1500,
62 				.val = 0x0,
63 			}, /* 1500 uG/LSB */
64 			.fs_len = 1,
65 		},
66 		.temp_comp = {
67 			.addr = 0x60,
68 			.mask = BIT(7),
69 		},
70 		.pwr_table = {
71 			.reg = {
72 				.addr = 0x60,
73 				.mask = GENMASK(1, 0),
74 			},
75 			.off_val = 0x2,
76 			.on_val = 0x0,
77 		},
78 		.off_canc = {
79 			.addr = 0x61,
80 			.mask = BIT(1),
81 		},
82 		.bdu = {
83 			.addr = 0x62,
84 			.mask = BIT(4),
85 		},
86 		.out = {
87 			.addr = 0x68,
88 			.len = 6,
89 		},
90 	},
91 	/* LIS3MDL */
92 	{
93 		.i2c_addr = { 0x1e },
94 		.wai = {
95 			.addr = 0x0f,
96 			.val = 0x3d,
97 		},
98 		.id = ST_LSM6DSX_ID_MAGN,
99 		.odr_table = {
100 			.reg = {
101 				.addr = 0x20,
102 				.mask = GENMASK(4, 2),
103 			},
104 			.odr_avl[0] = {  1000, 0x0 },
105 			.odr_avl[1] = {  2000, 0x1 },
106 			.odr_avl[2] = {  3000, 0x2 },
107 			.odr_avl[3] = {  5000, 0x3 },
108 			.odr_avl[4] = { 10000, 0x4 },
109 			.odr_avl[5] = { 20000, 0x5 },
110 			.odr_avl[6] = { 40000, 0x6 },
111 			.odr_avl[7] = { 80000, 0x7 },
112 			.odr_len = 8,
113 		},
114 		.fs_table = {
115 			.reg = {
116 				.addr = 0x21,
117 				.mask = GENMASK(6, 5),
118 			},
119 			.fs_avl[0] = {
120 				.gain = 146,
121 				.val = 0x00,
122 			}, /* 4000 uG/LSB */
123 			.fs_avl[1] = {
124 				.gain = 292,
125 				.val = 0x01,
126 			}, /* 8000 uG/LSB */
127 			.fs_avl[2] = {
128 				.gain = 438,
129 				.val = 0x02,
130 			}, /* 12000 uG/LSB */
131 			.fs_avl[3] = {
132 				.gain = 584,
133 				.val = 0x03,
134 			}, /* 16000 uG/LSB */
135 			.fs_len = 4,
136 		},
137 		.pwr_table = {
138 			.reg = {
139 				.addr = 0x22,
140 				.mask = GENMASK(1, 0),
141 			},
142 			.off_val = 0x2,
143 			.on_val = 0x0,
144 		},
145 		.bdu = {
146 			.addr = 0x24,
147 			.mask = BIT(6),
148 		},
149 		.out = {
150 			.addr = 0x28,
151 			.len = 6,
152 		},
153 	},
154 };
155 
156 static void st_lsm6dsx_shub_wait_complete(struct st_lsm6dsx_hw *hw)
157 {
158 	struct st_lsm6dsx_sensor *sensor;
159 	u32 odr;
160 
161 	sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
162 	odr = (hw->enable_mask & BIT(ST_LSM6DSX_ID_ACC)) ? sensor->odr : 12500;
163 	msleep((2000000U / odr) + 1);
164 }
165 
166 /**
167  * st_lsm6dsx_shub_read_output - read i2c controller register
168  *
169  * Read st_lsm6dsx i2c controller register
170  */
171 static int
172 st_lsm6dsx_shub_read_output(struct st_lsm6dsx_hw *hw, u8 *data,
173 			    int len)
174 {
175 	const struct st_lsm6dsx_shub_settings *hub_settings;
176 	int err;
177 
178 	mutex_lock(&hw->page_lock);
179 
180 	hub_settings = &hw->settings->shub_settings;
181 	if (hub_settings->shub_out.sec_page) {
182 		err = st_lsm6dsx_set_page(hw, true);
183 		if (err < 0)
184 			goto out;
185 	}
186 
187 	err = regmap_bulk_read(hw->regmap, hub_settings->shub_out.addr,
188 			       data, len);
189 
190 	if (hub_settings->shub_out.sec_page)
191 		st_lsm6dsx_set_page(hw, false);
192 out:
193 	mutex_unlock(&hw->page_lock);
194 
195 	return err;
196 }
197 
198 /**
199  * st_lsm6dsx_shub_write_reg - write i2c controller register
200  *
201  * Write st_lsm6dsx i2c controller register
202  */
203 static int st_lsm6dsx_shub_write_reg(struct st_lsm6dsx_hw *hw, u8 addr,
204 				     u8 *data, int len)
205 {
206 	int err;
207 
208 	mutex_lock(&hw->page_lock);
209 	err = st_lsm6dsx_set_page(hw, true);
210 	if (err < 0)
211 		goto out;
212 
213 	err = regmap_bulk_write(hw->regmap, addr, data, len);
214 
215 	st_lsm6dsx_set_page(hw, false);
216 out:
217 	mutex_unlock(&hw->page_lock);
218 
219 	return err;
220 }
221 
222 static int
223 st_lsm6dsx_shub_write_reg_with_mask(struct st_lsm6dsx_hw *hw, u8 addr,
224 				    u8 mask, u8 val)
225 {
226 	int err;
227 
228 	mutex_lock(&hw->page_lock);
229 	err = st_lsm6dsx_set_page(hw, true);
230 	if (err < 0)
231 		goto out;
232 
233 	err = regmap_update_bits(hw->regmap, addr, mask, val);
234 
235 	st_lsm6dsx_set_page(hw, false);
236 out:
237 	mutex_unlock(&hw->page_lock);
238 
239 	return err;
240 }
241 
242 static int st_lsm6dsx_shub_master_enable(struct st_lsm6dsx_sensor *sensor,
243 					 bool enable)
244 {
245 	const struct st_lsm6dsx_shub_settings *hub_settings;
246 	struct st_lsm6dsx_hw *hw = sensor->hw;
247 	unsigned int data;
248 	int err;
249 
250 	/* enable acc sensor as trigger */
251 	err = st_lsm6dsx_sensor_set_enable(sensor, enable);
252 	if (err < 0)
253 		return err;
254 
255 	mutex_lock(&hw->page_lock);
256 
257 	hub_settings = &hw->settings->shub_settings;
258 	if (hub_settings->master_en.sec_page) {
259 		err = st_lsm6dsx_set_page(hw, true);
260 		if (err < 0)
261 			goto out;
262 	}
263 
264 	data = ST_LSM6DSX_SHIFT_VAL(enable, hub_settings->master_en.mask);
265 	err = regmap_update_bits(hw->regmap, hub_settings->master_en.addr,
266 				 hub_settings->master_en.mask, data);
267 
268 	if (hub_settings->master_en.sec_page)
269 		st_lsm6dsx_set_page(hw, false);
270 out:
271 	mutex_unlock(&hw->page_lock);
272 
273 	return err;
274 }
275 
276 /**
277  * st_lsm6dsx_shub_read - read data from slave device register
278  *
279  * Read data from slave device register. SLV0 is used for
280  * one-shot read operation
281  */
282 static int
283 st_lsm6dsx_shub_read(struct st_lsm6dsx_sensor *sensor, u8 addr,
284 		     u8 *data, int len)
285 {
286 	const struct st_lsm6dsx_shub_settings *hub_settings;
287 	u8 config[3], slv_addr, slv_config = 0;
288 	struct st_lsm6dsx_hw *hw = sensor->hw;
289 	const struct st_lsm6dsx_reg *aux_sens;
290 	int err;
291 
292 	hub_settings = &hw->settings->shub_settings;
293 	slv_addr = ST_LSM6DSX_SLV_ADDR(0, hub_settings->slv0_addr);
294 	aux_sens = &hw->settings->shub_settings.aux_sens;
295 	/* do not overwrite aux_sens */
296 	if (slv_addr + 2 == aux_sens->addr)
297 		slv_config = ST_LSM6DSX_SHIFT_VAL(3, aux_sens->mask);
298 
299 	config[0] = (sensor->ext_info.addr << 1) | 1;
300 	config[1] = addr;
301 	config[2] = (len & ST_LS6DSX_READ_OP_MASK) | slv_config;
302 
303 	err = st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
304 					sizeof(config));
305 	if (err < 0)
306 		return err;
307 
308 	err = st_lsm6dsx_shub_master_enable(sensor, true);
309 	if (err < 0)
310 		return err;
311 
312 	st_lsm6dsx_shub_wait_complete(hw);
313 
314 	err = st_lsm6dsx_shub_read_output(hw, data,
315 					  len & ST_LS6DSX_READ_OP_MASK);
316 
317 	st_lsm6dsx_shub_master_enable(sensor, false);
318 
319 	config[0] = hub_settings->pause;
320 	config[1] = 0;
321 	config[2] = slv_config;
322 	return st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
323 					 sizeof(config));
324 }
325 
326 /**
327  * st_lsm6dsx_shub_write - write data to slave device register
328  *
329  * Write data from slave device register. SLV0 is used for
330  * one-shot write operation
331  */
332 static int
333 st_lsm6dsx_shub_write(struct st_lsm6dsx_sensor *sensor, u8 addr,
334 		      u8 *data, int len)
335 {
336 	const struct st_lsm6dsx_shub_settings *hub_settings;
337 	struct st_lsm6dsx_hw *hw = sensor->hw;
338 	u8 config[2], slv_addr;
339 	int err, i;
340 
341 	hub_settings = &hw->settings->shub_settings;
342 	if (hub_settings->wr_once.addr) {
343 		unsigned int data;
344 
345 		data = ST_LSM6DSX_SHIFT_VAL(1, hub_settings->wr_once.mask);
346 		err = st_lsm6dsx_shub_write_reg_with_mask(hw,
347 			hub_settings->wr_once.addr,
348 			hub_settings->wr_once.mask,
349 			data);
350 		if (err < 0)
351 			return err;
352 	}
353 
354 	slv_addr = ST_LSM6DSX_SLV_ADDR(0, hub_settings->slv0_addr);
355 	config[0] = sensor->ext_info.addr << 1;
356 	for (i = 0 ; i < len; i++) {
357 		config[1] = addr + i;
358 
359 		err = st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
360 						sizeof(config));
361 		if (err < 0)
362 			return err;
363 
364 		err = st_lsm6dsx_shub_write_reg(hw, hub_settings->dw_slv0_addr,
365 						&data[i], 1);
366 		if (err < 0)
367 			return err;
368 
369 		err = st_lsm6dsx_shub_master_enable(sensor, true);
370 		if (err < 0)
371 			return err;
372 
373 		st_lsm6dsx_shub_wait_complete(hw);
374 
375 		st_lsm6dsx_shub_master_enable(sensor, false);
376 	}
377 
378 	config[0] = hub_settings->pause;
379 	config[1] = 0;
380 	return st_lsm6dsx_shub_write_reg(hw, slv_addr, config, sizeof(config));
381 }
382 
383 static int
384 st_lsm6dsx_shub_write_with_mask(struct st_lsm6dsx_sensor *sensor,
385 				u8 addr, u8 mask, u8 val)
386 {
387 	int err;
388 	u8 data;
389 
390 	err = st_lsm6dsx_shub_read(sensor, addr, &data, sizeof(data));
391 	if (err < 0)
392 		return err;
393 
394 	data = ((data & ~mask) | (val << __ffs(mask) & mask));
395 
396 	return st_lsm6dsx_shub_write(sensor, addr, &data, sizeof(data));
397 }
398 
399 static int
400 st_lsm6dsx_shub_get_odr_val(struct st_lsm6dsx_sensor *sensor,
401 			    u32 odr, u16 *val)
402 {
403 	const struct st_lsm6dsx_ext_dev_settings *settings;
404 	int i;
405 
406 	settings = sensor->ext_info.settings;
407 	for (i = 0; i < settings->odr_table.odr_len; i++) {
408 		if (settings->odr_table.odr_avl[i].milli_hz == odr)
409 			break;
410 	}
411 
412 	if (i == settings->odr_table.odr_len)
413 		return -EINVAL;
414 
415 	*val = settings->odr_table.odr_avl[i].val;
416 	return 0;
417 }
418 
419 static int
420 st_lsm6dsx_shub_set_odr(struct st_lsm6dsx_sensor *sensor, u32 odr)
421 {
422 	const struct st_lsm6dsx_ext_dev_settings *settings;
423 	u16 val;
424 	int err;
425 
426 	err = st_lsm6dsx_shub_get_odr_val(sensor, odr, &val);
427 	if (err < 0)
428 		return err;
429 
430 	settings = sensor->ext_info.settings;
431 	return st_lsm6dsx_shub_write_with_mask(sensor,
432 					       settings->odr_table.reg.addr,
433 					       settings->odr_table.reg.mask,
434 					       val);
435 }
436 
437 /* use SLV{1,2,3} for FIFO read operations */
438 static int
439 st_lsm6dsx_shub_config_channels(struct st_lsm6dsx_sensor *sensor,
440 				bool enable)
441 {
442 	const struct st_lsm6dsx_shub_settings *hub_settings;
443 	const struct st_lsm6dsx_ext_dev_settings *settings;
444 	u8 config[9] = {}, enable_mask, slv_addr;
445 	struct st_lsm6dsx_hw *hw = sensor->hw;
446 	struct st_lsm6dsx_sensor *cur_sensor;
447 	int i, j = 0;
448 
449 	hub_settings = &hw->settings->shub_settings;
450 	if (enable)
451 		enable_mask = hw->enable_mask | BIT(sensor->id);
452 	else
453 		enable_mask = hw->enable_mask & ~BIT(sensor->id);
454 
455 	for (i = ST_LSM6DSX_ID_EXT0; i <= ST_LSM6DSX_ID_EXT2; i++) {
456 		if (!hw->iio_devs[i])
457 			continue;
458 
459 		cur_sensor = iio_priv(hw->iio_devs[i]);
460 		if (!(enable_mask & BIT(cur_sensor->id)))
461 			continue;
462 
463 		settings = cur_sensor->ext_info.settings;
464 		config[j] = (sensor->ext_info.addr << 1) | 1;
465 		config[j + 1] = settings->out.addr;
466 		config[j + 2] = (settings->out.len & ST_LS6DSX_READ_OP_MASK) |
467 				hub_settings->batch_en;
468 		j += 3;
469 	}
470 
471 	slv_addr = ST_LSM6DSX_SLV_ADDR(1, hub_settings->slv0_addr);
472 	return st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
473 					 sizeof(config));
474 }
475 
476 int st_lsm6dsx_shub_set_enable(struct st_lsm6dsx_sensor *sensor, bool enable)
477 {
478 	const struct st_lsm6dsx_ext_dev_settings *settings;
479 	int err;
480 
481 	err = st_lsm6dsx_shub_config_channels(sensor, enable);
482 	if (err < 0)
483 		return err;
484 
485 	settings = sensor->ext_info.settings;
486 	if (enable) {
487 		err = st_lsm6dsx_shub_set_odr(sensor,
488 					      sensor->ext_info.slv_odr);
489 		if (err < 0)
490 			return err;
491 	} else {
492 		err = st_lsm6dsx_shub_write_with_mask(sensor,
493 					settings->odr_table.reg.addr,
494 					settings->odr_table.reg.mask, 0);
495 		if (err < 0)
496 			return err;
497 	}
498 
499 	if (settings->pwr_table.reg.addr) {
500 		u8 val;
501 
502 		val = enable ? settings->pwr_table.on_val
503 			     : settings->pwr_table.off_val;
504 		err = st_lsm6dsx_shub_write_with_mask(sensor,
505 					settings->pwr_table.reg.addr,
506 					settings->pwr_table.reg.mask, val);
507 		if (err < 0)
508 			return err;
509 	}
510 
511 	return st_lsm6dsx_shub_master_enable(sensor, enable);
512 }
513 
514 static int
515 st_lsm6dsx_shub_read_oneshot(struct st_lsm6dsx_sensor *sensor,
516 			     struct iio_chan_spec const *ch,
517 			     int *val)
518 {
519 	int err, delay, len;
520 	u8 data[4];
521 
522 	err = st_lsm6dsx_shub_set_enable(sensor, true);
523 	if (err < 0)
524 		return err;
525 
526 	delay = 1000000000 / sensor->ext_info.slv_odr;
527 	usleep_range(delay, 2 * delay);
528 
529 	len = min_t(int, sizeof(data), ch->scan_type.realbits >> 3);
530 	err = st_lsm6dsx_shub_read(sensor, ch->address, data, len);
531 	if (err < 0)
532 		return err;
533 
534 	err = st_lsm6dsx_shub_set_enable(sensor, false);
535 	if (err < 0)
536 		return err;
537 
538 	switch (len) {
539 	case 2:
540 		*val = (s16)le16_to_cpu(*((__le16 *)data));
541 		break;
542 	default:
543 		return -EINVAL;
544 	}
545 
546 	return IIO_VAL_INT;
547 }
548 
549 static int
550 st_lsm6dsx_shub_read_raw(struct iio_dev *iio_dev,
551 			 struct iio_chan_spec const *ch,
552 			 int *val, int *val2, long mask)
553 {
554 	struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
555 	int ret;
556 
557 	switch (mask) {
558 	case IIO_CHAN_INFO_RAW:
559 		ret = iio_device_claim_direct_mode(iio_dev);
560 		if (ret)
561 			break;
562 
563 		ret = st_lsm6dsx_shub_read_oneshot(sensor, ch, val);
564 		iio_device_release_direct_mode(iio_dev);
565 		break;
566 	case IIO_CHAN_INFO_SAMP_FREQ:
567 		*val = sensor->ext_info.slv_odr / 1000;
568 		*val2 = (sensor->ext_info.slv_odr % 1000) * 1000;
569 		ret = IIO_VAL_INT_PLUS_MICRO;
570 		break;
571 	case IIO_CHAN_INFO_SCALE:
572 		*val = 0;
573 		*val2 = sensor->gain;
574 		ret = IIO_VAL_INT_PLUS_MICRO;
575 		break;
576 	default:
577 		ret = -EINVAL;
578 		break;
579 	}
580 
581 	return ret;
582 }
583 
584 static int
585 st_lsm6dsx_shub_set_full_scale(struct st_lsm6dsx_sensor *sensor,
586 			       u32 gain)
587 {
588 	const struct st_lsm6dsx_fs_table_entry *fs_table;
589 	int i, err;
590 
591 	fs_table = &sensor->ext_info.settings->fs_table;
592 	if (!fs_table->reg.addr)
593 		return -ENOTSUPP;
594 
595 	for (i = 0; i < fs_table->fs_len; i++) {
596 		if (fs_table->fs_avl[i].gain == gain)
597 			break;
598 	}
599 
600 	if (i == fs_table->fs_len)
601 		return -EINVAL;
602 
603 	err = st_lsm6dsx_shub_write_with_mask(sensor, fs_table->reg.addr,
604 					      fs_table->reg.mask,
605 					      fs_table->fs_avl[i].val);
606 	if (err < 0)
607 		return err;
608 
609 	sensor->gain = gain;
610 
611 	return 0;
612 }
613 
614 static int
615 st_lsm6dsx_shub_write_raw(struct iio_dev *iio_dev,
616 			  struct iio_chan_spec const *chan,
617 			  int val, int val2, long mask)
618 {
619 	struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
620 	int err;
621 
622 	err = iio_device_claim_direct_mode(iio_dev);
623 	if (err)
624 		return err;
625 
626 	switch (mask) {
627 	case IIO_CHAN_INFO_SAMP_FREQ: {
628 		u16 data;
629 
630 		val = val * 1000 + val2 / 1000;
631 		err = st_lsm6dsx_shub_get_odr_val(sensor, val, &data);
632 		if (!err) {
633 			struct st_lsm6dsx_hw *hw = sensor->hw;
634 			struct st_lsm6dsx_sensor *ref_sensor;
635 			u8 odr_val;
636 			int odr;
637 
638 			ref_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
639 			odr = st_lsm6dsx_check_odr(ref_sensor, val, &odr_val);
640 			if (odr < 0) {
641 				err = odr;
642 				goto release;
643 			}
644 
645 			sensor->ext_info.slv_odr = val;
646 			sensor->odr = odr;
647 		}
648 		break;
649 	}
650 	case IIO_CHAN_INFO_SCALE:
651 		err = st_lsm6dsx_shub_set_full_scale(sensor, val2);
652 		break;
653 	default:
654 		err = -EINVAL;
655 		break;
656 	}
657 
658 release:
659 	iio_device_release_direct_mode(iio_dev);
660 
661 	return err;
662 }
663 
664 static ssize_t
665 st_lsm6dsx_shub_sampling_freq_avail(struct device *dev,
666 				    struct device_attribute *attr,
667 				    char *buf)
668 {
669 	struct st_lsm6dsx_sensor *sensor = iio_priv(dev_get_drvdata(dev));
670 	const struct st_lsm6dsx_ext_dev_settings *settings;
671 	int i, len = 0;
672 
673 	settings = sensor->ext_info.settings;
674 	for (i = 0; i < settings->odr_table.odr_len; i++) {
675 		u32 val = settings->odr_table.odr_avl[i].milli_hz;
676 
677 		len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%03d ",
678 				 val / 1000, val % 1000);
679 	}
680 	buf[len - 1] = '\n';
681 
682 	return len;
683 }
684 
685 static ssize_t st_lsm6dsx_shub_scale_avail(struct device *dev,
686 					   struct device_attribute *attr,
687 					   char *buf)
688 {
689 	struct st_lsm6dsx_sensor *sensor = iio_priv(dev_get_drvdata(dev));
690 	const struct st_lsm6dsx_ext_dev_settings *settings;
691 	int i, len = 0;
692 
693 	settings = sensor->ext_info.settings;
694 	for (i = 0; i < settings->fs_table.fs_len; i++)
695 		len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06u ",
696 				 settings->fs_table.fs_avl[i].gain);
697 	buf[len - 1] = '\n';
698 
699 	return len;
700 }
701 
702 static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(st_lsm6dsx_shub_sampling_freq_avail);
703 static IIO_DEVICE_ATTR(in_scale_available, 0444,
704 		       st_lsm6dsx_shub_scale_avail, NULL, 0);
705 static struct attribute *st_lsm6dsx_ext_attributes[] = {
706 	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
707 	&iio_dev_attr_in_scale_available.dev_attr.attr,
708 	NULL,
709 };
710 
711 static const struct attribute_group st_lsm6dsx_ext_attribute_group = {
712 	.attrs = st_lsm6dsx_ext_attributes,
713 };
714 
715 static const struct iio_info st_lsm6dsx_ext_info = {
716 	.attrs = &st_lsm6dsx_ext_attribute_group,
717 	.read_raw = st_lsm6dsx_shub_read_raw,
718 	.write_raw = st_lsm6dsx_shub_write_raw,
719 	.hwfifo_set_watermark = st_lsm6dsx_set_watermark,
720 };
721 
722 static struct iio_dev *
723 st_lsm6dsx_shub_alloc_iiodev(struct st_lsm6dsx_hw *hw,
724 			     enum st_lsm6dsx_sensor_id id,
725 			     const struct st_lsm6dsx_ext_dev_settings *info,
726 			     u8 i2c_addr, const char *name)
727 {
728 	enum st_lsm6dsx_sensor_id ref_id = ST_LSM6DSX_ID_ACC;
729 	struct iio_chan_spec *ext_channels;
730 	struct st_lsm6dsx_sensor *sensor;
731 	struct iio_dev *iio_dev;
732 
733 	iio_dev = devm_iio_device_alloc(hw->dev, sizeof(*sensor));
734 	if (!iio_dev)
735 		return NULL;
736 
737 	iio_dev->modes = INDIO_DIRECT_MODE;
738 	iio_dev->dev.parent = hw->dev;
739 	iio_dev->info = &st_lsm6dsx_ext_info;
740 
741 	sensor = iio_priv(iio_dev);
742 	sensor->id = id;
743 	sensor->hw = hw;
744 	sensor->odr = hw->settings->odr_table[ref_id].odr_avl[0].milli_hz;
745 	sensor->ext_info.slv_odr = info->odr_table.odr_avl[0].milli_hz;
746 	sensor->gain = info->fs_table.fs_avl[0].gain;
747 	sensor->ext_info.settings = info;
748 	sensor->ext_info.addr = i2c_addr;
749 	sensor->watermark = 1;
750 
751 	switch (info->id) {
752 	case ST_LSM6DSX_ID_MAGN: {
753 		const struct iio_chan_spec magn_channels[] = {
754 			ST_LSM6DSX_CHANNEL(IIO_MAGN, info->out.addr,
755 					   IIO_MOD_X, 0),
756 			ST_LSM6DSX_CHANNEL(IIO_MAGN, info->out.addr + 2,
757 					   IIO_MOD_Y, 1),
758 			ST_LSM6DSX_CHANNEL(IIO_MAGN, info->out.addr + 4,
759 					   IIO_MOD_Z, 2),
760 			IIO_CHAN_SOFT_TIMESTAMP(3),
761 		};
762 
763 		ext_channels = devm_kzalloc(hw->dev, sizeof(magn_channels),
764 					    GFP_KERNEL);
765 		if (!ext_channels)
766 			return NULL;
767 
768 		memcpy(ext_channels, magn_channels, sizeof(magn_channels));
769 		iio_dev->available_scan_masks = st_lsm6dsx_available_scan_masks;
770 		iio_dev->channels = ext_channels;
771 		iio_dev->num_channels = ARRAY_SIZE(magn_channels);
772 
773 		scnprintf(sensor->name, sizeof(sensor->name), "%s_magn",
774 			  name);
775 		break;
776 	}
777 	default:
778 		return NULL;
779 	}
780 	iio_dev->name = sensor->name;
781 
782 	return iio_dev;
783 }
784 
785 static int st_lsm6dsx_shub_init_device(struct st_lsm6dsx_sensor *sensor)
786 {
787 	const struct st_lsm6dsx_ext_dev_settings *settings;
788 	int err;
789 
790 	settings = sensor->ext_info.settings;
791 	if (settings->bdu.addr) {
792 		err = st_lsm6dsx_shub_write_with_mask(sensor,
793 						      settings->bdu.addr,
794 						      settings->bdu.mask, 1);
795 		if (err < 0)
796 			return err;
797 	}
798 
799 	if (settings->temp_comp.addr) {
800 		err = st_lsm6dsx_shub_write_with_mask(sensor,
801 					settings->temp_comp.addr,
802 					settings->temp_comp.mask, 1);
803 		if (err < 0)
804 			return err;
805 	}
806 
807 	if (settings->off_canc.addr) {
808 		err = st_lsm6dsx_shub_write_with_mask(sensor,
809 					settings->off_canc.addr,
810 					settings->off_canc.mask, 1);
811 		if (err < 0)
812 			return err;
813 	}
814 
815 	return 0;
816 }
817 
818 static int
819 st_lsm6dsx_shub_check_wai(struct st_lsm6dsx_hw *hw, u8 *i2c_addr,
820 			  const struct st_lsm6dsx_ext_dev_settings *settings)
821 {
822 	const struct st_lsm6dsx_shub_settings *hub_settings;
823 	u8 config[3], data, slv_addr, slv_config = 0;
824 	const struct st_lsm6dsx_reg *aux_sens;
825 	struct st_lsm6dsx_sensor *sensor;
826 	bool found = false;
827 	int i, err;
828 
829 	sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
830 	hub_settings = &hw->settings->shub_settings;
831 	aux_sens = &hw->settings->shub_settings.aux_sens;
832 	slv_addr = ST_LSM6DSX_SLV_ADDR(0, hub_settings->slv0_addr);
833 	/* do not overwrite aux_sens */
834 	if (slv_addr + 2 == aux_sens->addr)
835 		slv_config = ST_LSM6DSX_SHIFT_VAL(3, aux_sens->mask);
836 
837 	for (i = 0; i < ARRAY_SIZE(settings->i2c_addr); i++) {
838 		if (!settings->i2c_addr[i])
839 			continue;
840 
841 		/* read wai slave register */
842 		config[0] = (settings->i2c_addr[i] << 1) | 0x1;
843 		config[1] = settings->wai.addr;
844 		config[2] = 0x1 | slv_config;
845 
846 		err = st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
847 						sizeof(config));
848 		if (err < 0)
849 			return err;
850 
851 		err = st_lsm6dsx_shub_master_enable(sensor, true);
852 		if (err < 0)
853 			return err;
854 
855 		st_lsm6dsx_shub_wait_complete(hw);
856 
857 		err = st_lsm6dsx_shub_read_output(hw, &data, sizeof(data));
858 
859 		st_lsm6dsx_shub_master_enable(sensor, false);
860 
861 		if (err < 0)
862 			return err;
863 
864 		if (data != settings->wai.val)
865 			continue;
866 
867 		*i2c_addr = settings->i2c_addr[i];
868 		found = true;
869 		break;
870 	}
871 
872 	/* reset SLV0 channel */
873 	config[0] = hub_settings->pause;
874 	config[1] = 0;
875 	config[2] = slv_config;
876 	err = st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
877 					sizeof(config));
878 	if (err < 0)
879 		return err;
880 
881 	return found ? 0 : -ENODEV;
882 }
883 
884 int st_lsm6dsx_shub_probe(struct st_lsm6dsx_hw *hw, const char *name)
885 {
886 	enum st_lsm6dsx_sensor_id id = ST_LSM6DSX_ID_EXT0;
887 	struct st_lsm6dsx_sensor *sensor;
888 	int err, i, num_ext_dev = 0;
889 	u8 i2c_addr = 0;
890 
891 	for (i = 0; i < ARRAY_SIZE(st_lsm6dsx_ext_dev_table); i++) {
892 		err = st_lsm6dsx_shub_check_wai(hw, &i2c_addr,
893 					&st_lsm6dsx_ext_dev_table[i]);
894 		if (err == -ENODEV)
895 			continue;
896 		else if (err < 0)
897 			return err;
898 
899 		hw->iio_devs[id] = st_lsm6dsx_shub_alloc_iiodev(hw, id,
900 						&st_lsm6dsx_ext_dev_table[i],
901 						i2c_addr, name);
902 		if (!hw->iio_devs[id])
903 			return -ENOMEM;
904 
905 		sensor = iio_priv(hw->iio_devs[id]);
906 		err = st_lsm6dsx_shub_init_device(sensor);
907 		if (err < 0)
908 			return err;
909 
910 		if (++num_ext_dev >= hw->settings->shub_settings.num_ext_dev)
911 			break;
912 		id++;
913 	}
914 
915 	return 0;
916 }
917