xref: /openbmc/linux/drivers/iio/common/st_sensors/st_sensors_core.c (revision 7ae9fb1b7ecbb5d85d07857943f677fd1a559b18)
1  // SPDX-License-Identifier: GPL-2.0-only
2  /*
3   * STMicroelectronics sensors core library driver
4   *
5   * Copyright 2012-2013 STMicroelectronics Inc.
6   *
7   * Denis Ciocca <denis.ciocca@st.com>
8   */
9  
10  #include <linux/kernel.h>
11  #include <linux/module.h>
12  #include <linux/slab.h>
13  #include <linux/delay.h>
14  #include <linux/iio/iio.h>
15  #include <linux/mutex.h>
16  #include <linux/property.h>
17  #include <linux/regulator/consumer.h>
18  #include <linux/regmap.h>
19  #include <asm/unaligned.h>
20  #include <linux/iio/common/st_sensors.h>
21  
22  #include "st_sensors_core.h"
23  
st_sensors_write_data_with_mask(struct iio_dev * indio_dev,u8 reg_addr,u8 mask,u8 data)24  int st_sensors_write_data_with_mask(struct iio_dev *indio_dev,
25  				    u8 reg_addr, u8 mask, u8 data)
26  {
27  	struct st_sensor_data *sdata = iio_priv(indio_dev);
28  
29  	return regmap_update_bits(sdata->regmap,
30  				  reg_addr, mask, data << __ffs(mask));
31  }
32  
st_sensors_debugfs_reg_access(struct iio_dev * indio_dev,unsigned reg,unsigned writeval,unsigned * readval)33  int st_sensors_debugfs_reg_access(struct iio_dev *indio_dev,
34  				  unsigned reg, unsigned writeval,
35  				  unsigned *readval)
36  {
37  	struct st_sensor_data *sdata = iio_priv(indio_dev);
38  	int err;
39  
40  	if (!readval)
41  		return regmap_write(sdata->regmap, reg, writeval);
42  
43  	err = regmap_read(sdata->regmap, reg, readval);
44  	if (err < 0)
45  		return err;
46  
47  	return 0;
48  }
49  EXPORT_SYMBOL_NS(st_sensors_debugfs_reg_access, IIO_ST_SENSORS);
50  
st_sensors_match_odr(struct st_sensor_settings * sensor_settings,unsigned int odr,struct st_sensor_odr_avl * odr_out)51  static int st_sensors_match_odr(struct st_sensor_settings *sensor_settings,
52  			unsigned int odr, struct st_sensor_odr_avl *odr_out)
53  {
54  	int i, ret = -EINVAL;
55  
56  	for (i = 0; i < ST_SENSORS_ODR_LIST_MAX; i++) {
57  		if (sensor_settings->odr.odr_avl[i].hz == 0)
58  			goto st_sensors_match_odr_error;
59  
60  		if (sensor_settings->odr.odr_avl[i].hz == odr) {
61  			odr_out->hz = sensor_settings->odr.odr_avl[i].hz;
62  			odr_out->value = sensor_settings->odr.odr_avl[i].value;
63  			ret = 0;
64  			break;
65  		}
66  	}
67  
68  st_sensors_match_odr_error:
69  	return ret;
70  }
71  
st_sensors_set_odr(struct iio_dev * indio_dev,unsigned int odr)72  int st_sensors_set_odr(struct iio_dev *indio_dev, unsigned int odr)
73  {
74  	int err = 0;
75  	struct st_sensor_odr_avl odr_out = {0, 0};
76  	struct st_sensor_data *sdata = iio_priv(indio_dev);
77  
78  	mutex_lock(&sdata->odr_lock);
79  
80  	if (!sdata->sensor_settings->odr.mask)
81  		goto unlock_mutex;
82  
83  	err = st_sensors_match_odr(sdata->sensor_settings, odr, &odr_out);
84  	if (err < 0)
85  		goto unlock_mutex;
86  
87  	if ((sdata->sensor_settings->odr.addr ==
88  					sdata->sensor_settings->pw.addr) &&
89  				(sdata->sensor_settings->odr.mask ==
90  					sdata->sensor_settings->pw.mask)) {
91  		if (sdata->enabled == true) {
92  			err = st_sensors_write_data_with_mask(indio_dev,
93  				sdata->sensor_settings->odr.addr,
94  				sdata->sensor_settings->odr.mask,
95  				odr_out.value);
96  		} else {
97  			err = 0;
98  		}
99  	} else {
100  		err = st_sensors_write_data_with_mask(indio_dev,
101  			sdata->sensor_settings->odr.addr,
102  			sdata->sensor_settings->odr.mask,
103  			odr_out.value);
104  	}
105  	if (err >= 0)
106  		sdata->odr = odr_out.hz;
107  
108  unlock_mutex:
109  	mutex_unlock(&sdata->odr_lock);
110  
111  	return err;
112  }
113  EXPORT_SYMBOL_NS(st_sensors_set_odr, IIO_ST_SENSORS);
114  
st_sensors_match_fs(struct st_sensor_settings * sensor_settings,unsigned int fs,int * index_fs_avl)115  static int st_sensors_match_fs(struct st_sensor_settings *sensor_settings,
116  					unsigned int fs, int *index_fs_avl)
117  {
118  	int i, ret = -EINVAL;
119  
120  	for (i = 0; i < ST_SENSORS_FULLSCALE_AVL_MAX; i++) {
121  		if (sensor_settings->fs.fs_avl[i].num == 0)
122  			return ret;
123  
124  		if (sensor_settings->fs.fs_avl[i].num == fs) {
125  			*index_fs_avl = i;
126  			ret = 0;
127  			break;
128  		}
129  	}
130  
131  	return ret;
132  }
133  
st_sensors_set_fullscale(struct iio_dev * indio_dev,unsigned int fs)134  static int st_sensors_set_fullscale(struct iio_dev *indio_dev, unsigned int fs)
135  {
136  	int err, i = 0;
137  	struct st_sensor_data *sdata = iio_priv(indio_dev);
138  
139  	if (sdata->sensor_settings->fs.addr == 0)
140  		return 0;
141  
142  	err = st_sensors_match_fs(sdata->sensor_settings, fs, &i);
143  	if (err < 0)
144  		goto st_accel_set_fullscale_error;
145  
146  	err = st_sensors_write_data_with_mask(indio_dev,
147  				sdata->sensor_settings->fs.addr,
148  				sdata->sensor_settings->fs.mask,
149  				sdata->sensor_settings->fs.fs_avl[i].value);
150  	if (err < 0)
151  		goto st_accel_set_fullscale_error;
152  
153  	sdata->current_fullscale = &sdata->sensor_settings->fs.fs_avl[i];
154  	return err;
155  
156  st_accel_set_fullscale_error:
157  	dev_err(&indio_dev->dev, "failed to set new fullscale.\n");
158  	return err;
159  }
160  
st_sensors_set_enable(struct iio_dev * indio_dev,bool enable)161  int st_sensors_set_enable(struct iio_dev *indio_dev, bool enable)
162  {
163  	u8 tmp_value;
164  	int err = -EINVAL;
165  	bool found = false;
166  	struct st_sensor_odr_avl odr_out = {0, 0};
167  	struct st_sensor_data *sdata = iio_priv(indio_dev);
168  
169  	if (enable) {
170  		tmp_value = sdata->sensor_settings->pw.value_on;
171  		if ((sdata->sensor_settings->odr.addr ==
172  					sdata->sensor_settings->pw.addr) &&
173  				(sdata->sensor_settings->odr.mask ==
174  					sdata->sensor_settings->pw.mask)) {
175  			err = st_sensors_match_odr(sdata->sensor_settings,
176  							sdata->odr, &odr_out);
177  			if (err < 0)
178  				goto set_enable_error;
179  			tmp_value = odr_out.value;
180  			found = true;
181  		}
182  		err = st_sensors_write_data_with_mask(indio_dev,
183  				sdata->sensor_settings->pw.addr,
184  				sdata->sensor_settings->pw.mask, tmp_value);
185  		if (err < 0)
186  			goto set_enable_error;
187  
188  		sdata->enabled = true;
189  
190  		if (found)
191  			sdata->odr = odr_out.hz;
192  	} else {
193  		err = st_sensors_write_data_with_mask(indio_dev,
194  				sdata->sensor_settings->pw.addr,
195  				sdata->sensor_settings->pw.mask,
196  				sdata->sensor_settings->pw.value_off);
197  		if (err < 0)
198  			goto set_enable_error;
199  
200  		sdata->enabled = false;
201  	}
202  
203  set_enable_error:
204  	return err;
205  }
206  EXPORT_SYMBOL_NS(st_sensors_set_enable, IIO_ST_SENSORS);
207  
st_sensors_set_axis_enable(struct iio_dev * indio_dev,u8 axis_enable)208  int st_sensors_set_axis_enable(struct iio_dev *indio_dev, u8 axis_enable)
209  {
210  	struct st_sensor_data *sdata = iio_priv(indio_dev);
211  	int err = 0;
212  
213  	if (sdata->sensor_settings->enable_axis.addr)
214  		err = st_sensors_write_data_with_mask(indio_dev,
215  				sdata->sensor_settings->enable_axis.addr,
216  				sdata->sensor_settings->enable_axis.mask,
217  				axis_enable);
218  	return err;
219  }
220  EXPORT_SYMBOL_NS(st_sensors_set_axis_enable, IIO_ST_SENSORS);
221  
222  
st_sensors_power_enable(struct iio_dev * indio_dev)223  int st_sensors_power_enable(struct iio_dev *indio_dev)
224  {
225  	static const char * const regulator_names[] = { "vdd", "vddio" };
226  	struct device *parent = indio_dev->dev.parent;
227  	int err;
228  
229  	/* Regulators not mandatory, but if requested we should enable them. */
230  	err = devm_regulator_bulk_get_enable(parent,
231  					     ARRAY_SIZE(regulator_names),
232  					     regulator_names);
233  	if (err)
234  		return dev_err_probe(&indio_dev->dev, err,
235  				     "unable to enable supplies\n");
236  
237  	return 0;
238  }
239  EXPORT_SYMBOL_NS(st_sensors_power_enable, IIO_ST_SENSORS);
240  
st_sensors_set_drdy_int_pin(struct iio_dev * indio_dev,struct st_sensors_platform_data * pdata)241  static int st_sensors_set_drdy_int_pin(struct iio_dev *indio_dev,
242  					struct st_sensors_platform_data *pdata)
243  {
244  	struct st_sensor_data *sdata = iio_priv(indio_dev);
245  
246  	/* Sensor does not support interrupts */
247  	if (!sdata->sensor_settings->drdy_irq.int1.addr &&
248  	    !sdata->sensor_settings->drdy_irq.int2.addr) {
249  		if (pdata->drdy_int_pin)
250  			dev_info(&indio_dev->dev,
251  				 "DRDY on pin INT%d specified, but sensor does not support interrupts\n",
252  				 pdata->drdy_int_pin);
253  		return 0;
254  	}
255  
256  	switch (pdata->drdy_int_pin) {
257  	case 1:
258  		if (!sdata->sensor_settings->drdy_irq.int1.mask) {
259  			dev_err(&indio_dev->dev,
260  					"DRDY on INT1 not available.\n");
261  			return -EINVAL;
262  		}
263  		sdata->drdy_int_pin = 1;
264  		break;
265  	case 2:
266  		if (!sdata->sensor_settings->drdy_irq.int2.mask) {
267  			dev_err(&indio_dev->dev,
268  					"DRDY on INT2 not available.\n");
269  			return -EINVAL;
270  		}
271  		sdata->drdy_int_pin = 2;
272  		break;
273  	default:
274  		dev_err(&indio_dev->dev, "DRDY on pdata not valid.\n");
275  		return -EINVAL;
276  	}
277  
278  	if (pdata->open_drain) {
279  		if (!sdata->sensor_settings->drdy_irq.int1.addr_od &&
280  		    !sdata->sensor_settings->drdy_irq.int2.addr_od)
281  			dev_err(&indio_dev->dev,
282  				"open drain requested but unsupported.\n");
283  		else
284  			sdata->int_pin_open_drain = true;
285  	}
286  
287  	return 0;
288  }
289  
st_sensors_dev_probe(struct device * dev,struct st_sensors_platform_data * defdata)290  static struct st_sensors_platform_data *st_sensors_dev_probe(struct device *dev,
291  		struct st_sensors_platform_data *defdata)
292  {
293  	struct st_sensors_platform_data *pdata;
294  	u32 val;
295  
296  	if (!dev_fwnode(dev))
297  		return NULL;
298  
299  	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
300  	if (!pdata)
301  		return ERR_PTR(-ENOMEM);
302  	if (!device_property_read_u32(dev, "st,drdy-int-pin", &val) && (val <= 2))
303  		pdata->drdy_int_pin = (u8) val;
304  	else
305  		pdata->drdy_int_pin = defdata ? defdata->drdy_int_pin : 0;
306  
307  	pdata->open_drain = device_property_read_bool(dev, "drive-open-drain");
308  
309  	return pdata;
310  }
311  
312  /**
313   * st_sensors_dev_name_probe() - device probe for ST sensor name
314   * @dev: driver model representation of the device.
315   * @name: device name buffer reference.
316   * @len: device name buffer length.
317   *
318   * In effect this function matches an ID to an internal kernel
319   * name for a certain sensor device, so that the rest of the autodetection can
320   * rely on that name from this point on. I2C/SPI devices will be renamed
321   * to match the internal kernel convention.
322   */
st_sensors_dev_name_probe(struct device * dev,char * name,int len)323  void st_sensors_dev_name_probe(struct device *dev, char *name, int len)
324  {
325  	const void *match;
326  
327  	match = device_get_match_data(dev);
328  	if (!match)
329  		return;
330  
331  	/* The name from the match takes precedence if present */
332  	strscpy(name, match, len);
333  }
334  EXPORT_SYMBOL_NS(st_sensors_dev_name_probe, IIO_ST_SENSORS);
335  
st_sensors_init_sensor(struct iio_dev * indio_dev,struct st_sensors_platform_data * pdata)336  int st_sensors_init_sensor(struct iio_dev *indio_dev,
337  					struct st_sensors_platform_data *pdata)
338  {
339  	struct st_sensor_data *sdata = iio_priv(indio_dev);
340  	struct st_sensors_platform_data *of_pdata;
341  	int err = 0;
342  
343  	mutex_init(&sdata->odr_lock);
344  
345  	/* If OF/DT pdata exists, it will take precedence of anything else */
346  	of_pdata = st_sensors_dev_probe(indio_dev->dev.parent, pdata);
347  	if (IS_ERR(of_pdata))
348  		return PTR_ERR(of_pdata);
349  	if (of_pdata)
350  		pdata = of_pdata;
351  
352  	if (pdata) {
353  		err = st_sensors_set_drdy_int_pin(indio_dev, pdata);
354  		if (err < 0)
355  			return err;
356  	}
357  
358  	err = st_sensors_set_enable(indio_dev, false);
359  	if (err < 0)
360  		return err;
361  
362  	/* Disable DRDY, this might be still be enabled after reboot. */
363  	err = st_sensors_set_dataready_irq(indio_dev, false);
364  	if (err < 0)
365  		return err;
366  
367  	if (sdata->current_fullscale) {
368  		err = st_sensors_set_fullscale(indio_dev,
369  						sdata->current_fullscale->num);
370  		if (err < 0)
371  			return err;
372  	} else
373  		dev_info(&indio_dev->dev, "Full-scale not possible\n");
374  
375  	err = st_sensors_set_odr(indio_dev, sdata->odr);
376  	if (err < 0)
377  		return err;
378  
379  	/* set BDU */
380  	if (sdata->sensor_settings->bdu.addr) {
381  		err = st_sensors_write_data_with_mask(indio_dev,
382  					sdata->sensor_settings->bdu.addr,
383  					sdata->sensor_settings->bdu.mask, true);
384  		if (err < 0)
385  			return err;
386  	}
387  
388  	/* set DAS */
389  	if (sdata->sensor_settings->das.addr) {
390  		err = st_sensors_write_data_with_mask(indio_dev,
391  					sdata->sensor_settings->das.addr,
392  					sdata->sensor_settings->das.mask, 1);
393  		if (err < 0)
394  			return err;
395  	}
396  
397  	if (sdata->int_pin_open_drain) {
398  		u8 addr, mask;
399  
400  		if (sdata->drdy_int_pin == 1) {
401  			addr = sdata->sensor_settings->drdy_irq.int1.addr_od;
402  			mask = sdata->sensor_settings->drdy_irq.int1.mask_od;
403  		} else {
404  			addr = sdata->sensor_settings->drdy_irq.int2.addr_od;
405  			mask = sdata->sensor_settings->drdy_irq.int2.mask_od;
406  		}
407  
408  		dev_info(&indio_dev->dev,
409  			 "set interrupt line to open drain mode on pin %d\n",
410  			 sdata->drdy_int_pin);
411  		err = st_sensors_write_data_with_mask(indio_dev, addr,
412  						      mask, 1);
413  		if (err < 0)
414  			return err;
415  	}
416  
417  	err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
418  
419  	return err;
420  }
421  EXPORT_SYMBOL_NS(st_sensors_init_sensor, IIO_ST_SENSORS);
422  
st_sensors_set_dataready_irq(struct iio_dev * indio_dev,bool enable)423  int st_sensors_set_dataready_irq(struct iio_dev *indio_dev, bool enable)
424  {
425  	int err;
426  	u8 drdy_addr, drdy_mask;
427  	struct st_sensor_data *sdata = iio_priv(indio_dev);
428  
429  	if (!sdata->sensor_settings->drdy_irq.int1.addr &&
430  	    !sdata->sensor_settings->drdy_irq.int2.addr) {
431  		/*
432  		 * there are some devices (e.g. LIS3MDL) where drdy line is
433  		 * routed to a given pin and it is not possible to select a
434  		 * different one. Take into account irq status register
435  		 * to understand if irq trigger can be properly supported
436  		 */
437  		if (sdata->sensor_settings->drdy_irq.stat_drdy.addr)
438  			sdata->hw_irq_trigger = enable;
439  		return 0;
440  	}
441  
442  	/* Enable/Disable the interrupt generator 1. */
443  	if (sdata->sensor_settings->drdy_irq.ig1.en_addr > 0) {
444  		err = st_sensors_write_data_with_mask(indio_dev,
445  				sdata->sensor_settings->drdy_irq.ig1.en_addr,
446  				sdata->sensor_settings->drdy_irq.ig1.en_mask,
447  				(int)enable);
448  		if (err < 0)
449  			goto st_accel_set_dataready_irq_error;
450  	}
451  
452  	if (sdata->drdy_int_pin == 1) {
453  		drdy_addr = sdata->sensor_settings->drdy_irq.int1.addr;
454  		drdy_mask = sdata->sensor_settings->drdy_irq.int1.mask;
455  	} else {
456  		drdy_addr = sdata->sensor_settings->drdy_irq.int2.addr;
457  		drdy_mask = sdata->sensor_settings->drdy_irq.int2.mask;
458  	}
459  
460  	/* Flag to the poll function that the hardware trigger is in use */
461  	sdata->hw_irq_trigger = enable;
462  
463  	/* Enable/Disable the interrupt generator for data ready. */
464  	err = st_sensors_write_data_with_mask(indio_dev, drdy_addr,
465  					      drdy_mask, (int)enable);
466  
467  st_accel_set_dataready_irq_error:
468  	return err;
469  }
470  EXPORT_SYMBOL_NS(st_sensors_set_dataready_irq, IIO_ST_SENSORS);
471  
st_sensors_set_fullscale_by_gain(struct iio_dev * indio_dev,int scale)472  int st_sensors_set_fullscale_by_gain(struct iio_dev *indio_dev, int scale)
473  {
474  	int err = -EINVAL, i;
475  	struct st_sensor_data *sdata = iio_priv(indio_dev);
476  
477  	for (i = 0; i < ST_SENSORS_FULLSCALE_AVL_MAX; i++) {
478  		if ((sdata->sensor_settings->fs.fs_avl[i].gain == scale) &&
479  				(sdata->sensor_settings->fs.fs_avl[i].gain != 0)) {
480  			err = 0;
481  			break;
482  		}
483  	}
484  	if (err < 0)
485  		goto st_sensors_match_scale_error;
486  
487  	err = st_sensors_set_fullscale(indio_dev,
488  				sdata->sensor_settings->fs.fs_avl[i].num);
489  
490  st_sensors_match_scale_error:
491  	return err;
492  }
493  EXPORT_SYMBOL_NS(st_sensors_set_fullscale_by_gain, IIO_ST_SENSORS);
494  
st_sensors_read_axis_data(struct iio_dev * indio_dev,struct iio_chan_spec const * ch,int * data)495  static int st_sensors_read_axis_data(struct iio_dev *indio_dev,
496  				     struct iio_chan_spec const *ch, int *data)
497  {
498  	int err;
499  	u8 *outdata;
500  	struct st_sensor_data *sdata = iio_priv(indio_dev);
501  	unsigned int byte_for_channel;
502  
503  	byte_for_channel = DIV_ROUND_UP(ch->scan_type.realbits +
504  					ch->scan_type.shift, 8);
505  	outdata = kmalloc(byte_for_channel, GFP_DMA | GFP_KERNEL);
506  	if (!outdata)
507  		return -ENOMEM;
508  
509  	err = regmap_bulk_read(sdata->regmap, ch->address,
510  			       outdata, byte_for_channel);
511  	if (err < 0)
512  		goto st_sensors_free_memory;
513  
514  	if (byte_for_channel == 1)
515  		*data = (s8)*outdata;
516  	else if (byte_for_channel == 2)
517  		*data = (s16)get_unaligned_le16(outdata);
518  	else if (byte_for_channel == 3)
519  		*data = (s32)sign_extend32(get_unaligned_le24(outdata), 23);
520  
521  st_sensors_free_memory:
522  	kfree(outdata);
523  
524  	return err;
525  }
526  
st_sensors_read_info_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * ch,int * val)527  int st_sensors_read_info_raw(struct iio_dev *indio_dev,
528  				struct iio_chan_spec const *ch, int *val)
529  {
530  	int err;
531  	struct st_sensor_data *sdata = iio_priv(indio_dev);
532  
533  	err = iio_device_claim_direct_mode(indio_dev);
534  	if (err)
535  		return err;
536  
537  	mutex_lock(&sdata->odr_lock);
538  
539  	err = st_sensors_set_enable(indio_dev, true);
540  	if (err < 0)
541  		goto out;
542  
543  	msleep((sdata->sensor_settings->bootime * 1000) / sdata->odr);
544  	err = st_sensors_read_axis_data(indio_dev, ch, val);
545  	if (err < 0)
546  		goto out;
547  
548  	*val = *val >> ch->scan_type.shift;
549  
550  	err = st_sensors_set_enable(indio_dev, false);
551  
552  out:
553  	mutex_unlock(&sdata->odr_lock);
554  	iio_device_release_direct_mode(indio_dev);
555  
556  	return err;
557  }
558  EXPORT_SYMBOL_NS(st_sensors_read_info_raw, IIO_ST_SENSORS);
559  
560  /*
561   * st_sensors_get_settings_index() - get index of the sensor settings for a
562   *				     specific device from list of settings
563   * @name: device name buffer reference.
564   * @list: sensor settings list.
565   * @list_length: length of sensor settings list.
566   *
567   * Return: non negative number on success (valid index),
568   *	   negative error code otherwise.
569   */
st_sensors_get_settings_index(const char * name,const struct st_sensor_settings * list,const int list_length)570  int st_sensors_get_settings_index(const char *name,
571  				  const struct st_sensor_settings *list,
572  				  const int list_length)
573  {
574  	int i, n;
575  
576  	for (i = 0; i < list_length; i++) {
577  		for (n = 0; n < ST_SENSORS_MAX_4WAI; n++) {
578  			if (strcmp(name, list[i].sensors_supported[n]) == 0)
579  				return i;
580  		}
581  	}
582  
583  	return -ENODEV;
584  }
585  EXPORT_SYMBOL_NS(st_sensors_get_settings_index, IIO_ST_SENSORS);
586  
587  /*
588   * st_sensors_verify_id() - verify sensor ID (WhoAmI) is matching with the
589   *			    expected value
590   * @indio_dev: IIO device reference.
591   *
592   * Return: 0 on success (valid sensor ID), else a negative error code.
593   */
st_sensors_verify_id(struct iio_dev * indio_dev)594  int st_sensors_verify_id(struct iio_dev *indio_dev)
595  {
596  	struct st_sensor_data *sdata = iio_priv(indio_dev);
597  	int wai, err;
598  
599  	if (sdata->sensor_settings->wai_addr) {
600  		err = regmap_read(sdata->regmap,
601  				  sdata->sensor_settings->wai_addr, &wai);
602  		if (err < 0) {
603  			dev_err(&indio_dev->dev,
604  				"failed to read Who-Am-I register.\n");
605  			return err;
606  		}
607  
608  		if (sdata->sensor_settings->wai != wai) {
609  			dev_err(&indio_dev->dev,
610  				"%s: WhoAmI mismatch (0x%x).\n",
611  				indio_dev->name, wai);
612  			return -EINVAL;
613  		}
614  	}
615  
616  	return 0;
617  }
618  EXPORT_SYMBOL_NS(st_sensors_verify_id, IIO_ST_SENSORS);
619  
st_sensors_sysfs_sampling_frequency_avail(struct device * dev,struct device_attribute * attr,char * buf)620  ssize_t st_sensors_sysfs_sampling_frequency_avail(struct device *dev,
621  				struct device_attribute *attr, char *buf)
622  {
623  	int i, len = 0;
624  	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
625  	struct st_sensor_data *sdata = iio_priv(indio_dev);
626  
627  	for (i = 0; i < ST_SENSORS_ODR_LIST_MAX; i++) {
628  		if (sdata->sensor_settings->odr.odr_avl[i].hz == 0)
629  			break;
630  
631  		len += scnprintf(buf + len, PAGE_SIZE - len, "%d ",
632  				sdata->sensor_settings->odr.odr_avl[i].hz);
633  	}
634  	buf[len - 1] = '\n';
635  
636  	return len;
637  }
638  EXPORT_SYMBOL_NS(st_sensors_sysfs_sampling_frequency_avail, IIO_ST_SENSORS);
639  
st_sensors_sysfs_scale_avail(struct device * dev,struct device_attribute * attr,char * buf)640  ssize_t st_sensors_sysfs_scale_avail(struct device *dev,
641  				struct device_attribute *attr, char *buf)
642  {
643  	int i, len = 0, q, r;
644  	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
645  	struct st_sensor_data *sdata = iio_priv(indio_dev);
646  
647  	for (i = 0; i < ST_SENSORS_FULLSCALE_AVL_MAX; i++) {
648  		if (sdata->sensor_settings->fs.fs_avl[i].num == 0)
649  			break;
650  
651  		q = sdata->sensor_settings->fs.fs_avl[i].gain / 1000000;
652  		r = sdata->sensor_settings->fs.fs_avl[i].gain % 1000000;
653  
654  		len += scnprintf(buf + len, PAGE_SIZE - len, "%u.%06u ", q, r);
655  	}
656  	buf[len - 1] = '\n';
657  
658  	return len;
659  }
660  EXPORT_SYMBOL_NS(st_sensors_sysfs_scale_avail, IIO_ST_SENSORS);
661  
662  MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
663  MODULE_DESCRIPTION("STMicroelectronics ST-sensors core");
664  MODULE_LICENSE("GPL v2");
665