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, timeout;
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 	/* set 10ms as minimum timeout for i2c slave configuration */
164 	timeout = max_t(u32, 2000000U / odr + 1, 10);
165 	msleep(timeout);
166 }
167 
168 /*
169  * st_lsm6dsx_shub_read_output - read i2c controller register
170  *
171  * Read st_lsm6dsx i2c controller register
172  */
173 static int
174 st_lsm6dsx_shub_read_output(struct st_lsm6dsx_hw *hw, u8 *data,
175 			    int len)
176 {
177 	const struct st_lsm6dsx_shub_settings *hub_settings;
178 	int err;
179 
180 	mutex_lock(&hw->page_lock);
181 
182 	hub_settings = &hw->settings->shub_settings;
183 	if (hub_settings->shub_out.sec_page) {
184 		err = st_lsm6dsx_set_page(hw, true);
185 		if (err < 0)
186 			goto out;
187 	}
188 
189 	err = regmap_bulk_read(hw->regmap, hub_settings->shub_out.addr,
190 			       data, len);
191 
192 	if (hub_settings->shub_out.sec_page)
193 		st_lsm6dsx_set_page(hw, false);
194 out:
195 	mutex_unlock(&hw->page_lock);
196 
197 	return err;
198 }
199 
200 /*
201  * st_lsm6dsx_shub_write_reg - write i2c controller register
202  *
203  * Write st_lsm6dsx i2c controller register
204  */
205 static int st_lsm6dsx_shub_write_reg(struct st_lsm6dsx_hw *hw, u8 addr,
206 				     u8 *data, int len)
207 {
208 	int err;
209 
210 	mutex_lock(&hw->page_lock);
211 	err = st_lsm6dsx_set_page(hw, true);
212 	if (err < 0)
213 		goto out;
214 
215 	err = regmap_bulk_write(hw->regmap, addr, data, len);
216 
217 	st_lsm6dsx_set_page(hw, false);
218 out:
219 	mutex_unlock(&hw->page_lock);
220 
221 	return err;
222 }
223 
224 static int
225 st_lsm6dsx_shub_write_reg_with_mask(struct st_lsm6dsx_hw *hw, u8 addr,
226 				    u8 mask, u8 val)
227 {
228 	int err;
229 
230 	mutex_lock(&hw->page_lock);
231 	err = st_lsm6dsx_set_page(hw, true);
232 	if (err < 0)
233 		goto out;
234 
235 	err = regmap_update_bits(hw->regmap, addr, mask, val);
236 
237 	st_lsm6dsx_set_page(hw, false);
238 out:
239 	mutex_unlock(&hw->page_lock);
240 
241 	return err;
242 }
243 
244 static int st_lsm6dsx_shub_master_enable(struct st_lsm6dsx_sensor *sensor,
245 					 bool enable)
246 {
247 	const struct st_lsm6dsx_shub_settings *hub_settings;
248 	struct st_lsm6dsx_hw *hw = sensor->hw;
249 	unsigned int data;
250 	int err;
251 
252 	/* enable acc sensor as trigger */
253 	err = st_lsm6dsx_sensor_set_enable(sensor, enable);
254 	if (err < 0)
255 		return err;
256 
257 	mutex_lock(&hw->page_lock);
258 
259 	hub_settings = &hw->settings->shub_settings;
260 	if (hub_settings->master_en.sec_page) {
261 		err = st_lsm6dsx_set_page(hw, true);
262 		if (err < 0)
263 			goto out;
264 	}
265 
266 	data = ST_LSM6DSX_SHIFT_VAL(enable, hub_settings->master_en.mask);
267 	err = regmap_update_bits(hw->regmap, hub_settings->master_en.addr,
268 				 hub_settings->master_en.mask, data);
269 
270 	if (hub_settings->master_en.sec_page)
271 		st_lsm6dsx_set_page(hw, false);
272 out:
273 	mutex_unlock(&hw->page_lock);
274 
275 	return err;
276 }
277 
278 /*
279  * st_lsm6dsx_shub_read - read data from slave device register
280  *
281  * Read data from slave device register. SLV0 is used for
282  * one-shot read operation
283  */
284 static int
285 st_lsm6dsx_shub_read(struct st_lsm6dsx_sensor *sensor, u8 addr,
286 		     u8 *data, int len)
287 {
288 	const struct st_lsm6dsx_shub_settings *hub_settings;
289 	u8 config[3], slv_addr, slv_config = 0;
290 	struct st_lsm6dsx_hw *hw = sensor->hw;
291 	const struct st_lsm6dsx_reg *aux_sens;
292 	int err;
293 
294 	hub_settings = &hw->settings->shub_settings;
295 	slv_addr = ST_LSM6DSX_SLV_ADDR(0, hub_settings->slv0_addr);
296 	aux_sens = &hw->settings->shub_settings.aux_sens;
297 	/* do not overwrite aux_sens */
298 	if (slv_addr + 2 == aux_sens->addr)
299 		slv_config = ST_LSM6DSX_SHIFT_VAL(3, aux_sens->mask);
300 
301 	config[0] = (sensor->ext_info.addr << 1) | 1;
302 	config[1] = addr;
303 	config[2] = (len & ST_LS6DSX_READ_OP_MASK) | slv_config;
304 
305 	err = st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
306 					sizeof(config));
307 	if (err < 0)
308 		return err;
309 
310 	err = st_lsm6dsx_shub_master_enable(sensor, true);
311 	if (err < 0)
312 		return err;
313 
314 	st_lsm6dsx_shub_wait_complete(hw);
315 
316 	err = st_lsm6dsx_shub_read_output(hw, data,
317 					  len & ST_LS6DSX_READ_OP_MASK);
318 	if (err < 0)
319 		return err;
320 
321 	st_lsm6dsx_shub_master_enable(sensor, false);
322 
323 	config[0] = hub_settings->pause;
324 	config[1] = 0;
325 	config[2] = slv_config;
326 	return st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
327 					 sizeof(config));
328 }
329 
330 /*
331  * st_lsm6dsx_shub_write - write data to slave device register
332  *
333  * Write data from slave device register. SLV0 is used for
334  * one-shot write operation
335  */
336 static int
337 st_lsm6dsx_shub_write(struct st_lsm6dsx_sensor *sensor, u8 addr,
338 		      u8 *data, int len)
339 {
340 	const struct st_lsm6dsx_shub_settings *hub_settings;
341 	struct st_lsm6dsx_hw *hw = sensor->hw;
342 	u8 config[2], slv_addr;
343 	int err, i;
344 
345 	hub_settings = &hw->settings->shub_settings;
346 	if (hub_settings->wr_once.addr) {
347 		unsigned int data;
348 
349 		data = ST_LSM6DSX_SHIFT_VAL(1, hub_settings->wr_once.mask);
350 		err = st_lsm6dsx_shub_write_reg_with_mask(hw,
351 			hub_settings->wr_once.addr,
352 			hub_settings->wr_once.mask,
353 			data);
354 		if (err < 0)
355 			return err;
356 	}
357 
358 	slv_addr = ST_LSM6DSX_SLV_ADDR(0, hub_settings->slv0_addr);
359 	config[0] = sensor->ext_info.addr << 1;
360 	for (i = 0 ; i < len; i++) {
361 		config[1] = addr + i;
362 
363 		err = st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
364 						sizeof(config));
365 		if (err < 0)
366 			return err;
367 
368 		err = st_lsm6dsx_shub_write_reg(hw, hub_settings->dw_slv0_addr,
369 						&data[i], 1);
370 		if (err < 0)
371 			return err;
372 
373 		err = st_lsm6dsx_shub_master_enable(sensor, true);
374 		if (err < 0)
375 			return err;
376 
377 		st_lsm6dsx_shub_wait_complete(hw);
378 
379 		st_lsm6dsx_shub_master_enable(sensor, false);
380 	}
381 
382 	config[0] = hub_settings->pause;
383 	config[1] = 0;
384 	return st_lsm6dsx_shub_write_reg(hw, slv_addr, config, sizeof(config));
385 }
386 
387 static int
388 st_lsm6dsx_shub_write_with_mask(struct st_lsm6dsx_sensor *sensor,
389 				u8 addr, u8 mask, u8 val)
390 {
391 	int err;
392 	u8 data;
393 
394 	err = st_lsm6dsx_shub_read(sensor, addr, &data, sizeof(data));
395 	if (err < 0)
396 		return err;
397 
398 	data = ((data & ~mask) | (val << __ffs(mask) & mask));
399 
400 	return st_lsm6dsx_shub_write(sensor, addr, &data, sizeof(data));
401 }
402 
403 static int
404 st_lsm6dsx_shub_get_odr_val(struct st_lsm6dsx_sensor *sensor,
405 			    u32 odr, u16 *val)
406 {
407 	const struct st_lsm6dsx_ext_dev_settings *settings;
408 	int i;
409 
410 	settings = sensor->ext_info.settings;
411 	for (i = 0; i < settings->odr_table.odr_len; i++) {
412 		if (settings->odr_table.odr_avl[i].milli_hz == odr)
413 			break;
414 	}
415 
416 	if (i == settings->odr_table.odr_len)
417 		return -EINVAL;
418 
419 	*val = settings->odr_table.odr_avl[i].val;
420 	return 0;
421 }
422 
423 static int
424 st_lsm6dsx_shub_set_odr(struct st_lsm6dsx_sensor *sensor, u32 odr)
425 {
426 	const struct st_lsm6dsx_ext_dev_settings *settings;
427 	u16 val;
428 	int err;
429 
430 	err = st_lsm6dsx_shub_get_odr_val(sensor, odr, &val);
431 	if (err < 0)
432 		return err;
433 
434 	settings = sensor->ext_info.settings;
435 	return st_lsm6dsx_shub_write_with_mask(sensor,
436 					       settings->odr_table.reg.addr,
437 					       settings->odr_table.reg.mask,
438 					       val);
439 }
440 
441 /* use SLV{1,2,3} for FIFO read operations */
442 static int
443 st_lsm6dsx_shub_config_channels(struct st_lsm6dsx_sensor *sensor,
444 				bool enable)
445 {
446 	const struct st_lsm6dsx_shub_settings *hub_settings;
447 	const struct st_lsm6dsx_ext_dev_settings *settings;
448 	u8 config[9] = {}, enable_mask, slv_addr;
449 	struct st_lsm6dsx_hw *hw = sensor->hw;
450 	struct st_lsm6dsx_sensor *cur_sensor;
451 	int i, j = 0;
452 
453 	hub_settings = &hw->settings->shub_settings;
454 	if (enable)
455 		enable_mask = hw->enable_mask | BIT(sensor->id);
456 	else
457 		enable_mask = hw->enable_mask & ~BIT(sensor->id);
458 
459 	for (i = ST_LSM6DSX_ID_EXT0; i <= ST_LSM6DSX_ID_EXT2; i++) {
460 		if (!hw->iio_devs[i])
461 			continue;
462 
463 		cur_sensor = iio_priv(hw->iio_devs[i]);
464 		if (!(enable_mask & BIT(cur_sensor->id)))
465 			continue;
466 
467 		settings = cur_sensor->ext_info.settings;
468 		config[j] = (sensor->ext_info.addr << 1) | 1;
469 		config[j + 1] = settings->out.addr;
470 		config[j + 2] = (settings->out.len & ST_LS6DSX_READ_OP_MASK) |
471 				hub_settings->batch_en;
472 		j += 3;
473 	}
474 
475 	slv_addr = ST_LSM6DSX_SLV_ADDR(1, hub_settings->slv0_addr);
476 	return st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
477 					 sizeof(config));
478 }
479 
480 int st_lsm6dsx_shub_set_enable(struct st_lsm6dsx_sensor *sensor, bool enable)
481 {
482 	const struct st_lsm6dsx_ext_dev_settings *settings;
483 	int err;
484 
485 	err = st_lsm6dsx_shub_config_channels(sensor, enable);
486 	if (err < 0)
487 		return err;
488 
489 	settings = sensor->ext_info.settings;
490 	if (enable) {
491 		err = st_lsm6dsx_shub_set_odr(sensor,
492 					      sensor->ext_info.slv_odr);
493 		if (err < 0)
494 			return err;
495 	} else {
496 		err = st_lsm6dsx_shub_write_with_mask(sensor,
497 					settings->odr_table.reg.addr,
498 					settings->odr_table.reg.mask, 0);
499 		if (err < 0)
500 			return err;
501 	}
502 
503 	if (settings->pwr_table.reg.addr) {
504 		u8 val;
505 
506 		val = enable ? settings->pwr_table.on_val
507 			     : settings->pwr_table.off_val;
508 		err = st_lsm6dsx_shub_write_with_mask(sensor,
509 					settings->pwr_table.reg.addr,
510 					settings->pwr_table.reg.mask, val);
511 		if (err < 0)
512 			return err;
513 	}
514 
515 	return st_lsm6dsx_shub_master_enable(sensor, enable);
516 }
517 
518 static int
519 st_lsm6dsx_shub_read_oneshot(struct st_lsm6dsx_sensor *sensor,
520 			     struct iio_chan_spec const *ch,
521 			     int *val)
522 {
523 	int err, delay, len;
524 	u8 data[4];
525 
526 	err = st_lsm6dsx_shub_set_enable(sensor, true);
527 	if (err < 0)
528 		return err;
529 
530 	delay = 1000000000 / sensor->ext_info.slv_odr;
531 	usleep_range(delay, 2 * delay);
532 
533 	len = min_t(int, sizeof(data), ch->scan_type.realbits >> 3);
534 	err = st_lsm6dsx_shub_read(sensor, ch->address, data, len);
535 	if (err < 0)
536 		return err;
537 
538 	err = st_lsm6dsx_shub_set_enable(sensor, false);
539 	if (err < 0)
540 		return err;
541 
542 	switch (len) {
543 	case 2:
544 		*val = (s16)le16_to_cpu(*((__le16 *)data));
545 		break;
546 	default:
547 		return -EINVAL;
548 	}
549 
550 	return IIO_VAL_INT;
551 }
552 
553 static int
554 st_lsm6dsx_shub_read_raw(struct iio_dev *iio_dev,
555 			 struct iio_chan_spec const *ch,
556 			 int *val, int *val2, long mask)
557 {
558 	struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
559 	int ret;
560 
561 	switch (mask) {
562 	case IIO_CHAN_INFO_RAW:
563 		ret = iio_device_claim_direct_mode(iio_dev);
564 		if (ret)
565 			break;
566 
567 		ret = st_lsm6dsx_shub_read_oneshot(sensor, ch, val);
568 		iio_device_release_direct_mode(iio_dev);
569 		break;
570 	case IIO_CHAN_INFO_SAMP_FREQ:
571 		*val = sensor->ext_info.slv_odr / 1000;
572 		*val2 = (sensor->ext_info.slv_odr % 1000) * 1000;
573 		ret = IIO_VAL_INT_PLUS_MICRO;
574 		break;
575 	case IIO_CHAN_INFO_SCALE:
576 		*val = 0;
577 		*val2 = sensor->gain;
578 		ret = IIO_VAL_INT_PLUS_MICRO;
579 		break;
580 	default:
581 		ret = -EINVAL;
582 		break;
583 	}
584 
585 	return ret;
586 }
587 
588 static int
589 st_lsm6dsx_shub_set_full_scale(struct st_lsm6dsx_sensor *sensor,
590 			       u32 gain)
591 {
592 	const struct st_lsm6dsx_fs_table_entry *fs_table;
593 	int i, err;
594 
595 	fs_table = &sensor->ext_info.settings->fs_table;
596 	if (!fs_table->reg.addr)
597 		return -ENOTSUPP;
598 
599 	for (i = 0; i < fs_table->fs_len; i++) {
600 		if (fs_table->fs_avl[i].gain == gain)
601 			break;
602 	}
603 
604 	if (i == fs_table->fs_len)
605 		return -EINVAL;
606 
607 	err = st_lsm6dsx_shub_write_with_mask(sensor, fs_table->reg.addr,
608 					      fs_table->reg.mask,
609 					      fs_table->fs_avl[i].val);
610 	if (err < 0)
611 		return err;
612 
613 	sensor->gain = gain;
614 
615 	return 0;
616 }
617 
618 static int
619 st_lsm6dsx_shub_write_raw(struct iio_dev *iio_dev,
620 			  struct iio_chan_spec const *chan,
621 			  int val, int val2, long mask)
622 {
623 	struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
624 	int err;
625 
626 	err = iio_device_claim_direct_mode(iio_dev);
627 	if (err)
628 		return err;
629 
630 	switch (mask) {
631 	case IIO_CHAN_INFO_SAMP_FREQ: {
632 		u16 data;
633 
634 		val = val * 1000 + val2 / 1000;
635 		err = st_lsm6dsx_shub_get_odr_val(sensor, val, &data);
636 		if (!err) {
637 			struct st_lsm6dsx_hw *hw = sensor->hw;
638 			struct st_lsm6dsx_sensor *ref_sensor;
639 			u8 odr_val;
640 			int odr;
641 
642 			ref_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
643 			odr = st_lsm6dsx_check_odr(ref_sensor, val, &odr_val);
644 			if (odr < 0) {
645 				err = odr;
646 				goto release;
647 			}
648 
649 			sensor->ext_info.slv_odr = val;
650 			sensor->odr = odr;
651 		}
652 		break;
653 	}
654 	case IIO_CHAN_INFO_SCALE:
655 		err = st_lsm6dsx_shub_set_full_scale(sensor, val2);
656 		break;
657 	default:
658 		err = -EINVAL;
659 		break;
660 	}
661 
662 release:
663 	iio_device_release_direct_mode(iio_dev);
664 
665 	return err;
666 }
667 
668 static ssize_t
669 st_lsm6dsx_shub_sampling_freq_avail(struct device *dev,
670 				    struct device_attribute *attr,
671 				    char *buf)
672 {
673 	struct st_lsm6dsx_sensor *sensor = iio_priv(dev_get_drvdata(dev));
674 	const struct st_lsm6dsx_ext_dev_settings *settings;
675 	int i, len = 0;
676 
677 	settings = sensor->ext_info.settings;
678 	for (i = 0; i < settings->odr_table.odr_len; i++) {
679 		u32 val = settings->odr_table.odr_avl[i].milli_hz;
680 
681 		len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%03d ",
682 				 val / 1000, val % 1000);
683 	}
684 	buf[len - 1] = '\n';
685 
686 	return len;
687 }
688 
689 static ssize_t st_lsm6dsx_shub_scale_avail(struct device *dev,
690 					   struct device_attribute *attr,
691 					   char *buf)
692 {
693 	struct st_lsm6dsx_sensor *sensor = iio_priv(dev_get_drvdata(dev));
694 	const struct st_lsm6dsx_ext_dev_settings *settings;
695 	int i, len = 0;
696 
697 	settings = sensor->ext_info.settings;
698 	for (i = 0; i < settings->fs_table.fs_len; i++)
699 		len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06u ",
700 				 settings->fs_table.fs_avl[i].gain);
701 	buf[len - 1] = '\n';
702 
703 	return len;
704 }
705 
706 static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(st_lsm6dsx_shub_sampling_freq_avail);
707 static IIO_DEVICE_ATTR(in_scale_available, 0444,
708 		       st_lsm6dsx_shub_scale_avail, NULL, 0);
709 static struct attribute *st_lsm6dsx_ext_attributes[] = {
710 	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
711 	&iio_dev_attr_in_scale_available.dev_attr.attr,
712 	NULL,
713 };
714 
715 static const struct attribute_group st_lsm6dsx_ext_attribute_group = {
716 	.attrs = st_lsm6dsx_ext_attributes,
717 };
718 
719 static const struct iio_info st_lsm6dsx_ext_info = {
720 	.attrs = &st_lsm6dsx_ext_attribute_group,
721 	.read_raw = st_lsm6dsx_shub_read_raw,
722 	.write_raw = st_lsm6dsx_shub_write_raw,
723 	.hwfifo_set_watermark = st_lsm6dsx_set_watermark,
724 };
725 
726 static struct iio_dev *
727 st_lsm6dsx_shub_alloc_iiodev(struct st_lsm6dsx_hw *hw,
728 			     enum st_lsm6dsx_sensor_id id,
729 			     const struct st_lsm6dsx_ext_dev_settings *info,
730 			     u8 i2c_addr, const char *name)
731 {
732 	enum st_lsm6dsx_sensor_id ref_id = ST_LSM6DSX_ID_ACC;
733 	struct iio_chan_spec *ext_channels;
734 	struct st_lsm6dsx_sensor *sensor;
735 	struct iio_dev *iio_dev;
736 
737 	iio_dev = devm_iio_device_alloc(hw->dev, sizeof(*sensor));
738 	if (!iio_dev)
739 		return NULL;
740 
741 	iio_dev->modes = INDIO_DIRECT_MODE;
742 	iio_dev->info = &st_lsm6dsx_ext_info;
743 
744 	sensor = iio_priv(iio_dev);
745 	sensor->id = id;
746 	sensor->hw = hw;
747 	sensor->odr = hw->settings->odr_table[ref_id].odr_avl[0].milli_hz;
748 	sensor->ext_info.slv_odr = info->odr_table.odr_avl[0].milli_hz;
749 	sensor->gain = info->fs_table.fs_avl[0].gain;
750 	sensor->ext_info.settings = info;
751 	sensor->ext_info.addr = i2c_addr;
752 	sensor->watermark = 1;
753 
754 	switch (info->id) {
755 	case ST_LSM6DSX_ID_MAGN: {
756 		const struct iio_chan_spec magn_channels[] = {
757 			ST_LSM6DSX_CHANNEL(IIO_MAGN, info->out.addr,
758 					   IIO_MOD_X, 0),
759 			ST_LSM6DSX_CHANNEL(IIO_MAGN, info->out.addr + 2,
760 					   IIO_MOD_Y, 1),
761 			ST_LSM6DSX_CHANNEL(IIO_MAGN, info->out.addr + 4,
762 					   IIO_MOD_Z, 2),
763 			IIO_CHAN_SOFT_TIMESTAMP(3),
764 		};
765 
766 		ext_channels = devm_kzalloc(hw->dev, sizeof(magn_channels),
767 					    GFP_KERNEL);
768 		if (!ext_channels)
769 			return NULL;
770 
771 		memcpy(ext_channels, magn_channels, sizeof(magn_channels));
772 		iio_dev->available_scan_masks = st_lsm6dsx_available_scan_masks;
773 		iio_dev->channels = ext_channels;
774 		iio_dev->num_channels = ARRAY_SIZE(magn_channels);
775 
776 		scnprintf(sensor->name, sizeof(sensor->name), "%s_magn",
777 			  name);
778 		break;
779 	}
780 	default:
781 		return NULL;
782 	}
783 	iio_dev->name = sensor->name;
784 
785 	return iio_dev;
786 }
787 
788 static int st_lsm6dsx_shub_init_device(struct st_lsm6dsx_sensor *sensor)
789 {
790 	const struct st_lsm6dsx_ext_dev_settings *settings;
791 	int err;
792 
793 	settings = sensor->ext_info.settings;
794 	if (settings->bdu.addr) {
795 		err = st_lsm6dsx_shub_write_with_mask(sensor,
796 						      settings->bdu.addr,
797 						      settings->bdu.mask, 1);
798 		if (err < 0)
799 			return err;
800 	}
801 
802 	if (settings->temp_comp.addr) {
803 		err = st_lsm6dsx_shub_write_with_mask(sensor,
804 					settings->temp_comp.addr,
805 					settings->temp_comp.mask, 1);
806 		if (err < 0)
807 			return err;
808 	}
809 
810 	if (settings->off_canc.addr) {
811 		err = st_lsm6dsx_shub_write_with_mask(sensor,
812 					settings->off_canc.addr,
813 					settings->off_canc.mask, 1);
814 		if (err < 0)
815 			return err;
816 	}
817 
818 	return 0;
819 }
820 
821 static int
822 st_lsm6dsx_shub_check_wai(struct st_lsm6dsx_hw *hw, u8 *i2c_addr,
823 			  const struct st_lsm6dsx_ext_dev_settings *settings)
824 {
825 	const struct st_lsm6dsx_shub_settings *hub_settings;
826 	u8 config[3], data, slv_addr, slv_config = 0;
827 	const struct st_lsm6dsx_reg *aux_sens;
828 	struct st_lsm6dsx_sensor *sensor;
829 	bool found = false;
830 	int i, err;
831 
832 	sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
833 	hub_settings = &hw->settings->shub_settings;
834 	aux_sens = &hw->settings->shub_settings.aux_sens;
835 	slv_addr = ST_LSM6DSX_SLV_ADDR(0, hub_settings->slv0_addr);
836 	/* do not overwrite aux_sens */
837 	if (slv_addr + 2 == aux_sens->addr)
838 		slv_config = ST_LSM6DSX_SHIFT_VAL(3, aux_sens->mask);
839 
840 	for (i = 0; i < ARRAY_SIZE(settings->i2c_addr); i++) {
841 		if (!settings->i2c_addr[i])
842 			continue;
843 
844 		/* read wai slave register */
845 		config[0] = (settings->i2c_addr[i] << 1) | 0x1;
846 		config[1] = settings->wai.addr;
847 		config[2] = 0x1 | slv_config;
848 
849 		err = st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
850 						sizeof(config));
851 		if (err < 0)
852 			return err;
853 
854 		err = st_lsm6dsx_shub_master_enable(sensor, true);
855 		if (err < 0)
856 			return err;
857 
858 		st_lsm6dsx_shub_wait_complete(hw);
859 
860 		err = st_lsm6dsx_shub_read_output(hw, &data, sizeof(data));
861 
862 		st_lsm6dsx_shub_master_enable(sensor, false);
863 
864 		if (err < 0)
865 			return err;
866 
867 		if (data != settings->wai.val)
868 			continue;
869 
870 		*i2c_addr = settings->i2c_addr[i];
871 		found = true;
872 		break;
873 	}
874 
875 	/* reset SLV0 channel */
876 	config[0] = hub_settings->pause;
877 	config[1] = 0;
878 	config[2] = slv_config;
879 	err = st_lsm6dsx_shub_write_reg(hw, slv_addr, config,
880 					sizeof(config));
881 	if (err < 0)
882 		return err;
883 
884 	return found ? 0 : -ENODEV;
885 }
886 
887 int st_lsm6dsx_shub_probe(struct st_lsm6dsx_hw *hw, const char *name)
888 {
889 	enum st_lsm6dsx_sensor_id id = ST_LSM6DSX_ID_EXT0;
890 	struct st_lsm6dsx_sensor *sensor;
891 	int err, i, num_ext_dev = 0;
892 	u8 i2c_addr = 0;
893 
894 	for (i = 0; i < ARRAY_SIZE(st_lsm6dsx_ext_dev_table); i++) {
895 		err = st_lsm6dsx_shub_check_wai(hw, &i2c_addr,
896 					&st_lsm6dsx_ext_dev_table[i]);
897 		if (err == -ENODEV)
898 			continue;
899 		else if (err < 0)
900 			return err;
901 
902 		hw->iio_devs[id] = st_lsm6dsx_shub_alloc_iiodev(hw, id,
903 						&st_lsm6dsx_ext_dev_table[i],
904 						i2c_addr, name);
905 		if (!hw->iio_devs[id])
906 			return -ENOMEM;
907 
908 		sensor = iio_priv(hw->iio_devs[id]);
909 		err = st_lsm6dsx_shub_init_device(sensor);
910 		if (err < 0)
911 			return err;
912 
913 		if (++num_ext_dev >= hw->settings->shub_settings.num_ext_dev)
914 			break;
915 		id++;
916 	}
917 
918 	return 0;
919 }
920