1 /*
2  * STMicroelectronics sensors core library driver
3  *
4  * Copyright 2012-2013 STMicroelectronics Inc.
5  *
6  * Denis Ciocca <denis.ciocca@st.com>
7  *
8  * Licensed under the GPL-2.
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/delay.h>
15 #include <linux/iio/iio.h>
16 #include <linux/regulator/consumer.h>
17 #include <linux/of.h>
18 #include <asm/unaligned.h>
19 #include <linux/iio/common/st_sensors.h>
20 
21 
22 #define ST_SENSORS_WAI_ADDRESS		0x0f
23 
st_sensors_get_unaligned_le24(const u8 * p)24 static inline u32 st_sensors_get_unaligned_le24(const u8 *p)
25 {
26 	return (s32)((p[0] | p[1] << 8 | p[2] << 16) << 8) >> 8;
27 }
28 
st_sensors_write_data_with_mask(struct iio_dev * indio_dev,u8 reg_addr,u8 mask,u8 data)29 static int st_sensors_write_data_with_mask(struct iio_dev *indio_dev,
30 						u8 reg_addr, u8 mask, u8 data)
31 {
32 	int err;
33 	u8 new_data;
34 	struct st_sensor_data *sdata = iio_priv(indio_dev);
35 
36 	err = sdata->tf->read_byte(&sdata->tb, sdata->dev, reg_addr, &new_data);
37 	if (err < 0)
38 		goto st_sensors_write_data_with_mask_error;
39 
40 	new_data = ((new_data & (~mask)) | ((data << __ffs(mask)) & mask));
41 	err = sdata->tf->write_byte(&sdata->tb, sdata->dev, reg_addr, new_data);
42 
43 st_sensors_write_data_with_mask_error:
44 	return err;
45 }
46 
st_sensors_match_odr(struct st_sensor_settings * sensor_settings,unsigned int odr,struct st_sensor_odr_avl * odr_out)47 static int st_sensors_match_odr(struct st_sensor_settings *sensor_settings,
48 			unsigned int odr, struct st_sensor_odr_avl *odr_out)
49 {
50 	int i, ret = -EINVAL;
51 
52 	for (i = 0; i < ST_SENSORS_ODR_LIST_MAX; i++) {
53 		if (sensor_settings->odr.odr_avl[i].hz == 0)
54 			goto st_sensors_match_odr_error;
55 
56 		if (sensor_settings->odr.odr_avl[i].hz == odr) {
57 			odr_out->hz = sensor_settings->odr.odr_avl[i].hz;
58 			odr_out->value = sensor_settings->odr.odr_avl[i].value;
59 			ret = 0;
60 			break;
61 		}
62 	}
63 
64 st_sensors_match_odr_error:
65 	return ret;
66 }
67 
st_sensors_set_odr(struct iio_dev * indio_dev,unsigned int odr)68 int st_sensors_set_odr(struct iio_dev *indio_dev, unsigned int odr)
69 {
70 	int err;
71 	struct st_sensor_odr_avl odr_out = {0, 0};
72 	struct st_sensor_data *sdata = iio_priv(indio_dev);
73 
74 	err = st_sensors_match_odr(sdata->sensor_settings, odr, &odr_out);
75 	if (err < 0)
76 		goto st_sensors_match_odr_error;
77 
78 	if ((sdata->sensor_settings->odr.addr ==
79 					sdata->sensor_settings->pw.addr) &&
80 				(sdata->sensor_settings->odr.mask ==
81 					sdata->sensor_settings->pw.mask)) {
82 		if (sdata->enabled == true) {
83 			err = st_sensors_write_data_with_mask(indio_dev,
84 				sdata->sensor_settings->odr.addr,
85 				sdata->sensor_settings->odr.mask,
86 				odr_out.value);
87 		} else {
88 			err = 0;
89 		}
90 	} else {
91 		err = st_sensors_write_data_with_mask(indio_dev,
92 			sdata->sensor_settings->odr.addr,
93 			sdata->sensor_settings->odr.mask,
94 			odr_out.value);
95 	}
96 	if (err >= 0)
97 		sdata->odr = odr_out.hz;
98 
99 st_sensors_match_odr_error:
100 	return err;
101 }
102 EXPORT_SYMBOL(st_sensors_set_odr);
103 
st_sensors_match_fs(struct st_sensor_settings * sensor_settings,unsigned int fs,int * index_fs_avl)104 static int st_sensors_match_fs(struct st_sensor_settings *sensor_settings,
105 					unsigned int fs, int *index_fs_avl)
106 {
107 	int i, ret = -EINVAL;
108 
109 	for (i = 0; i < ST_SENSORS_FULLSCALE_AVL_MAX; i++) {
110 		if (sensor_settings->fs.fs_avl[i].num == 0)
111 			goto st_sensors_match_odr_error;
112 
113 		if (sensor_settings->fs.fs_avl[i].num == fs) {
114 			*index_fs_avl = i;
115 			ret = 0;
116 			break;
117 		}
118 	}
119 
120 st_sensors_match_odr_error:
121 	return ret;
122 }
123 
st_sensors_set_fullscale(struct iio_dev * indio_dev,unsigned int fs)124 static int st_sensors_set_fullscale(struct iio_dev *indio_dev, unsigned int fs)
125 {
126 	int err, i = 0;
127 	struct st_sensor_data *sdata = iio_priv(indio_dev);
128 
129 	err = st_sensors_match_fs(sdata->sensor_settings, fs, &i);
130 	if (err < 0)
131 		goto st_accel_set_fullscale_error;
132 
133 	err = st_sensors_write_data_with_mask(indio_dev,
134 				sdata->sensor_settings->fs.addr,
135 				sdata->sensor_settings->fs.mask,
136 				sdata->sensor_settings->fs.fs_avl[i].value);
137 	if (err < 0)
138 		goto st_accel_set_fullscale_error;
139 
140 	sdata->current_fullscale = (struct st_sensor_fullscale_avl *)
141 					&sdata->sensor_settings->fs.fs_avl[i];
142 	return err;
143 
144 st_accel_set_fullscale_error:
145 	dev_err(&indio_dev->dev, "failed to set new fullscale.\n");
146 	return err;
147 }
148 
st_sensors_set_enable(struct iio_dev * indio_dev,bool enable)149 int st_sensors_set_enable(struct iio_dev *indio_dev, bool enable)
150 {
151 	u8 tmp_value;
152 	int err = -EINVAL;
153 	bool found = false;
154 	struct st_sensor_odr_avl odr_out = {0, 0};
155 	struct st_sensor_data *sdata = iio_priv(indio_dev);
156 
157 	if (enable) {
158 		tmp_value = sdata->sensor_settings->pw.value_on;
159 		if ((sdata->sensor_settings->odr.addr ==
160 					sdata->sensor_settings->pw.addr) &&
161 				(sdata->sensor_settings->odr.mask ==
162 					sdata->sensor_settings->pw.mask)) {
163 			err = st_sensors_match_odr(sdata->sensor_settings,
164 							sdata->odr, &odr_out);
165 			if (err < 0)
166 				goto set_enable_error;
167 			tmp_value = odr_out.value;
168 			found = true;
169 		}
170 		err = st_sensors_write_data_with_mask(indio_dev,
171 				sdata->sensor_settings->pw.addr,
172 				sdata->sensor_settings->pw.mask, tmp_value);
173 		if (err < 0)
174 			goto set_enable_error;
175 
176 		sdata->enabled = true;
177 
178 		if (found)
179 			sdata->odr = odr_out.hz;
180 	} else {
181 		err = st_sensors_write_data_with_mask(indio_dev,
182 				sdata->sensor_settings->pw.addr,
183 				sdata->sensor_settings->pw.mask,
184 				sdata->sensor_settings->pw.value_off);
185 		if (err < 0)
186 			goto set_enable_error;
187 
188 		sdata->enabled = false;
189 	}
190 
191 set_enable_error:
192 	return err;
193 }
194 EXPORT_SYMBOL(st_sensors_set_enable);
195 
st_sensors_set_axis_enable(struct iio_dev * indio_dev,u8 axis_enable)196 int st_sensors_set_axis_enable(struct iio_dev *indio_dev, u8 axis_enable)
197 {
198 	struct st_sensor_data *sdata = iio_priv(indio_dev);
199 
200 	return st_sensors_write_data_with_mask(indio_dev,
201 				sdata->sensor_settings->enable_axis.addr,
202 				sdata->sensor_settings->enable_axis.mask,
203 				axis_enable);
204 }
205 EXPORT_SYMBOL(st_sensors_set_axis_enable);
206 
st_sensors_power_enable(struct iio_dev * indio_dev)207 void st_sensors_power_enable(struct iio_dev *indio_dev)
208 {
209 	struct st_sensor_data *pdata = iio_priv(indio_dev);
210 	int err;
211 
212 	/* Regulators not mandatory, but if requested we should enable them. */
213 	pdata->vdd = devm_regulator_get_optional(indio_dev->dev.parent, "vdd");
214 	if (!IS_ERR(pdata->vdd)) {
215 		err = regulator_enable(pdata->vdd);
216 		if (err != 0)
217 			dev_warn(&indio_dev->dev,
218 				 "Failed to enable specified Vdd supply\n");
219 	}
220 
221 	pdata->vdd_io = devm_regulator_get_optional(indio_dev->dev.parent, "vddio");
222 	if (!IS_ERR(pdata->vdd_io)) {
223 		err = regulator_enable(pdata->vdd_io);
224 		if (err != 0)
225 			dev_warn(&indio_dev->dev,
226 				 "Failed to enable specified Vdd_IO supply\n");
227 	}
228 }
229 EXPORT_SYMBOL(st_sensors_power_enable);
230 
st_sensors_power_disable(struct iio_dev * indio_dev)231 void st_sensors_power_disable(struct iio_dev *indio_dev)
232 {
233 	struct st_sensor_data *pdata = iio_priv(indio_dev);
234 
235 	if (!IS_ERR(pdata->vdd))
236 		regulator_disable(pdata->vdd);
237 
238 	if (!IS_ERR(pdata->vdd_io))
239 		regulator_disable(pdata->vdd_io);
240 }
241 EXPORT_SYMBOL(st_sensors_power_disable);
242 
st_sensors_set_drdy_int_pin(struct iio_dev * indio_dev,struct st_sensors_platform_data * pdata)243 static int st_sensors_set_drdy_int_pin(struct iio_dev *indio_dev,
244 					struct st_sensors_platform_data *pdata)
245 {
246 	struct st_sensor_data *sdata = iio_priv(indio_dev);
247 
248 	switch (pdata->drdy_int_pin) {
249 	case 1:
250 		if (sdata->sensor_settings->drdy_irq.mask_int1 == 0) {
251 			dev_err(&indio_dev->dev,
252 					"DRDY on INT1 not available.\n");
253 			return -EINVAL;
254 		}
255 		sdata->drdy_int_pin = 1;
256 		break;
257 	case 2:
258 		if (sdata->sensor_settings->drdy_irq.mask_int2 == 0) {
259 			dev_err(&indio_dev->dev,
260 					"DRDY on INT2 not available.\n");
261 			return -EINVAL;
262 		}
263 		sdata->drdy_int_pin = 2;
264 		break;
265 	default:
266 		dev_err(&indio_dev->dev, "DRDY on pdata not valid.\n");
267 		return -EINVAL;
268 	}
269 
270 	return 0;
271 }
272 
273 #ifdef CONFIG_OF
st_sensors_of_probe(struct device * dev,struct st_sensors_platform_data * defdata)274 static struct st_sensors_platform_data *st_sensors_of_probe(struct device *dev,
275 		struct st_sensors_platform_data *defdata)
276 {
277 	struct st_sensors_platform_data *pdata;
278 	struct device_node *np = dev->of_node;
279 	u32 val;
280 
281 	if (!np)
282 		return NULL;
283 
284 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
285 	if (!of_property_read_u32(np, "st,drdy-int-pin", &val) && (val <= 2))
286 		pdata->drdy_int_pin = (u8) val;
287 	else
288 		pdata->drdy_int_pin = defdata ? defdata->drdy_int_pin : 1;
289 
290 	return pdata;
291 }
292 #else
st_sensors_of_probe(struct device * dev,struct st_sensors_platform_data * defdata)293 static struct st_sensors_platform_data *st_sensors_of_probe(struct device *dev,
294 		struct st_sensors_platform_data *defdata)
295 {
296 	return NULL;
297 }
298 #endif
299 
st_sensors_init_sensor(struct iio_dev * indio_dev,struct st_sensors_platform_data * pdata)300 int st_sensors_init_sensor(struct iio_dev *indio_dev,
301 					struct st_sensors_platform_data *pdata)
302 {
303 	struct st_sensor_data *sdata = iio_priv(indio_dev);
304 	struct st_sensors_platform_data *of_pdata;
305 	int err = 0;
306 
307 	/* If OF/DT pdata exists, it will take precedence of anything else */
308 	of_pdata = st_sensors_of_probe(indio_dev->dev.parent, pdata);
309 	if (of_pdata)
310 		pdata = of_pdata;
311 
312 	if (pdata) {
313 		err = st_sensors_set_drdy_int_pin(indio_dev, pdata);
314 		if (err < 0)
315 			return err;
316 	}
317 
318 	err = st_sensors_set_enable(indio_dev, false);
319 	if (err < 0)
320 		return err;
321 
322 	if (sdata->current_fullscale) {
323 		err = st_sensors_set_fullscale(indio_dev,
324 						sdata->current_fullscale->num);
325 		if (err < 0)
326 			return err;
327 	} else
328 		dev_info(&indio_dev->dev, "Full-scale not possible\n");
329 
330 	err = st_sensors_set_odr(indio_dev, sdata->odr);
331 	if (err < 0)
332 		return err;
333 
334 	/* set BDU */
335 	err = st_sensors_write_data_with_mask(indio_dev,
336 					sdata->sensor_settings->bdu.addr,
337 					sdata->sensor_settings->bdu.mask, true);
338 	if (err < 0)
339 		return err;
340 
341 	err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
342 
343 	return err;
344 }
345 EXPORT_SYMBOL(st_sensors_init_sensor);
346 
st_sensors_set_dataready_irq(struct iio_dev * indio_dev,bool enable)347 int st_sensors_set_dataready_irq(struct iio_dev *indio_dev, bool enable)
348 {
349 	int err;
350 	u8 drdy_mask;
351 	struct st_sensor_data *sdata = iio_priv(indio_dev);
352 
353 	if (!sdata->sensor_settings->drdy_irq.addr)
354 		return 0;
355 
356 	/* Enable/Disable the interrupt generator 1. */
357 	if (sdata->sensor_settings->drdy_irq.ig1.en_addr > 0) {
358 		err = st_sensors_write_data_with_mask(indio_dev,
359 				sdata->sensor_settings->drdy_irq.ig1.en_addr,
360 				sdata->sensor_settings->drdy_irq.ig1.en_mask,
361 				(int)enable);
362 		if (err < 0)
363 			goto st_accel_set_dataready_irq_error;
364 	}
365 
366 	if (sdata->drdy_int_pin == 1)
367 		drdy_mask = sdata->sensor_settings->drdy_irq.mask_int1;
368 	else
369 		drdy_mask = sdata->sensor_settings->drdy_irq.mask_int2;
370 
371 	/* Enable/Disable the interrupt generator for data ready. */
372 	err = st_sensors_write_data_with_mask(indio_dev,
373 					sdata->sensor_settings->drdy_irq.addr,
374 					drdy_mask, (int)enable);
375 
376 st_accel_set_dataready_irq_error:
377 	return err;
378 }
379 EXPORT_SYMBOL(st_sensors_set_dataready_irq);
380 
st_sensors_set_fullscale_by_gain(struct iio_dev * indio_dev,int scale)381 int st_sensors_set_fullscale_by_gain(struct iio_dev *indio_dev, int scale)
382 {
383 	int err = -EINVAL, i;
384 	struct st_sensor_data *sdata = iio_priv(indio_dev);
385 
386 	for (i = 0; i < ST_SENSORS_FULLSCALE_AVL_MAX; i++) {
387 		if ((sdata->sensor_settings->fs.fs_avl[i].gain == scale) &&
388 				(sdata->sensor_settings->fs.fs_avl[i].gain != 0)) {
389 			err = 0;
390 			break;
391 		}
392 	}
393 	if (err < 0)
394 		goto st_sensors_match_scale_error;
395 
396 	err = st_sensors_set_fullscale(indio_dev,
397 				sdata->sensor_settings->fs.fs_avl[i].num);
398 
399 st_sensors_match_scale_error:
400 	return err;
401 }
402 EXPORT_SYMBOL(st_sensors_set_fullscale_by_gain);
403 
st_sensors_read_axis_data(struct iio_dev * indio_dev,struct iio_chan_spec const * ch,int * data)404 static int st_sensors_read_axis_data(struct iio_dev *indio_dev,
405 				struct iio_chan_spec const *ch, int *data)
406 {
407 	int err;
408 	u8 *outdata;
409 	struct st_sensor_data *sdata = iio_priv(indio_dev);
410 	unsigned int byte_for_channel = ch->scan_type.storagebits >> 3;
411 
412 	outdata = kmalloc(byte_for_channel, GFP_KERNEL);
413 	if (!outdata)
414 		return -ENOMEM;
415 
416 	err = sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
417 				ch->address, byte_for_channel,
418 				outdata, sdata->multiread_bit);
419 	if (err < 0)
420 		goto st_sensors_free_memory;
421 
422 	if (byte_for_channel == 2)
423 		*data = (s16)get_unaligned_le16(outdata);
424 	else if (byte_for_channel == 3)
425 		*data = (s32)st_sensors_get_unaligned_le24(outdata);
426 
427 st_sensors_free_memory:
428 	kfree(outdata);
429 
430 	return err;
431 }
432 
st_sensors_read_info_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * ch,int * val)433 int st_sensors_read_info_raw(struct iio_dev *indio_dev,
434 				struct iio_chan_spec const *ch, int *val)
435 {
436 	int err;
437 	struct st_sensor_data *sdata = iio_priv(indio_dev);
438 
439 	mutex_lock(&indio_dev->mlock);
440 	if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
441 		err = -EBUSY;
442 		goto out;
443 	} else {
444 		err = st_sensors_set_enable(indio_dev, true);
445 		if (err < 0)
446 			goto out;
447 
448 		msleep((sdata->sensor_settings->bootime * 1000) / sdata->odr);
449 		err = st_sensors_read_axis_data(indio_dev, ch, val);
450 		if (err < 0)
451 			goto out;
452 
453 		*val = *val >> ch->scan_type.shift;
454 
455 		err = st_sensors_set_enable(indio_dev, false);
456 	}
457 out:
458 	mutex_unlock(&indio_dev->mlock);
459 
460 	return err;
461 }
462 EXPORT_SYMBOL(st_sensors_read_info_raw);
463 
st_sensors_check_device_support(struct iio_dev * indio_dev,int num_sensors_list,const struct st_sensor_settings * sensor_settings)464 int st_sensors_check_device_support(struct iio_dev *indio_dev,
465 			int num_sensors_list,
466 			const struct st_sensor_settings *sensor_settings)
467 {
468 	u8 wai;
469 	int i, n, err;
470 	struct st_sensor_data *sdata = iio_priv(indio_dev);
471 
472 	err = sdata->tf->read_byte(&sdata->tb, sdata->dev,
473 					ST_SENSORS_DEFAULT_WAI_ADDRESS, &wai);
474 	if (err < 0) {
475 		dev_err(&indio_dev->dev, "failed to read Who-Am-I register.\n");
476 		goto read_wai_error;
477 	}
478 
479 	for (i = 0; i < num_sensors_list; i++) {
480 		if (sensor_settings[i].wai == wai)
481 			break;
482 	}
483 	if (i == num_sensors_list)
484 		goto device_not_supported;
485 
486 	for (n = 0; n < ARRAY_SIZE(sensor_settings[i].sensors_supported); n++) {
487 		if (strcmp(indio_dev->name,
488 				&sensor_settings[i].sensors_supported[n][0]) == 0)
489 			break;
490 	}
491 	if (n == ARRAY_SIZE(sensor_settings[i].sensors_supported)) {
492 		dev_err(&indio_dev->dev, "device name and WhoAmI mismatch.\n");
493 		goto sensor_name_mismatch;
494 	}
495 
496 	sdata->sensor_settings =
497 			(struct st_sensor_settings *)&sensor_settings[i];
498 
499 	return i;
500 
501 device_not_supported:
502 	dev_err(&indio_dev->dev, "device not supported: WhoAmI (0x%x).\n", wai);
503 sensor_name_mismatch:
504 	err = -ENODEV;
505 read_wai_error:
506 	return err;
507 }
508 EXPORT_SYMBOL(st_sensors_check_device_support);
509 
st_sensors_sysfs_sampling_frequency_avail(struct device * dev,struct device_attribute * attr,char * buf)510 ssize_t st_sensors_sysfs_sampling_frequency_avail(struct device *dev,
511 				struct device_attribute *attr, char *buf)
512 {
513 	int i, len = 0;
514 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
515 	struct st_sensor_data *sdata = iio_priv(indio_dev);
516 
517 	mutex_lock(&indio_dev->mlock);
518 	for (i = 0; i < ST_SENSORS_ODR_LIST_MAX; i++) {
519 		if (sdata->sensor_settings->odr.odr_avl[i].hz == 0)
520 			break;
521 
522 		len += scnprintf(buf + len, PAGE_SIZE - len, "%d ",
523 				sdata->sensor_settings->odr.odr_avl[i].hz);
524 	}
525 	mutex_unlock(&indio_dev->mlock);
526 	buf[len - 1] = '\n';
527 
528 	return len;
529 }
530 EXPORT_SYMBOL(st_sensors_sysfs_sampling_frequency_avail);
531 
st_sensors_sysfs_scale_avail(struct device * dev,struct device_attribute * attr,char * buf)532 ssize_t st_sensors_sysfs_scale_avail(struct device *dev,
533 				struct device_attribute *attr, char *buf)
534 {
535 	int i, len = 0;
536 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
537 	struct st_sensor_data *sdata = iio_priv(indio_dev);
538 
539 	mutex_lock(&indio_dev->mlock);
540 	for (i = 0; i < ST_SENSORS_FULLSCALE_AVL_MAX; i++) {
541 		if (sdata->sensor_settings->fs.fs_avl[i].num == 0)
542 			break;
543 
544 		len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06u ",
545 				sdata->sensor_settings->fs.fs_avl[i].gain);
546 	}
547 	mutex_unlock(&indio_dev->mlock);
548 	buf[len - 1] = '\n';
549 
550 	return len;
551 }
552 EXPORT_SYMBOL(st_sensors_sysfs_scale_avail);
553 
554 MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
555 MODULE_DESCRIPTION("STMicroelectronics ST-sensors core");
556 MODULE_LICENSE("GPL v2");
557