xref: /linux/drivers/iio/industrialio-core.c (revision e7d759f31ca295d589f7420719c311870bb3166f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * The industrial I/O core
4  *
5  * Copyright (c) 2008 Jonathan Cameron
6  *
7  * Based on elements of hwmon and input subsystems.
8  */
9 
10 #define pr_fmt(fmt) "iio-core: " fmt
11 
12 #include <linux/anon_inodes.h>
13 #include <linux/cdev.h>
14 #include <linux/debugfs.h>
15 #include <linux/device.h>
16 #include <linux/err.h>
17 #include <linux/fs.h>
18 #include <linux/idr.h>
19 #include <linux/kdev_t.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/mutex.h>
23 #include <linux/poll.h>
24 #include <linux/property.h>
25 #include <linux/sched.h>
26 #include <linux/slab.h>
27 #include <linux/wait.h>
28 
29 #include <linux/iio/buffer.h>
30 #include <linux/iio/buffer_impl.h>
31 #include <linux/iio/events.h>
32 #include <linux/iio/iio-opaque.h>
33 #include <linux/iio/iio.h>
34 #include <linux/iio/sysfs.h>
35 
36 #include "iio_core.h"
37 #include "iio_core_trigger.h"
38 
39 /* IDA to assign each registered device a unique id */
40 static DEFINE_IDA(iio_ida);
41 
42 static dev_t iio_devt;
43 
44 #define IIO_DEV_MAX 256
45 struct bus_type iio_bus_type = {
46 	.name = "iio",
47 };
48 EXPORT_SYMBOL(iio_bus_type);
49 
50 static struct dentry *iio_debugfs_dentry;
51 
52 static const char * const iio_direction[] = {
53 	[0] = "in",
54 	[1] = "out",
55 };
56 
57 static const char * const iio_chan_type_name_spec[] = {
58 	[IIO_VOLTAGE] = "voltage",
59 	[IIO_CURRENT] = "current",
60 	[IIO_POWER] = "power",
61 	[IIO_ACCEL] = "accel",
62 	[IIO_ANGL_VEL] = "anglvel",
63 	[IIO_MAGN] = "magn",
64 	[IIO_LIGHT] = "illuminance",
65 	[IIO_INTENSITY] = "intensity",
66 	[IIO_PROXIMITY] = "proximity",
67 	[IIO_TEMP] = "temp",
68 	[IIO_INCLI] = "incli",
69 	[IIO_ROT] = "rot",
70 	[IIO_ANGL] = "angl",
71 	[IIO_TIMESTAMP] = "timestamp",
72 	[IIO_CAPACITANCE] = "capacitance",
73 	[IIO_ALTVOLTAGE] = "altvoltage",
74 	[IIO_CCT] = "cct",
75 	[IIO_PRESSURE] = "pressure",
76 	[IIO_HUMIDITYRELATIVE] = "humidityrelative",
77 	[IIO_ACTIVITY] = "activity",
78 	[IIO_STEPS] = "steps",
79 	[IIO_ENERGY] = "energy",
80 	[IIO_DISTANCE] = "distance",
81 	[IIO_VELOCITY] = "velocity",
82 	[IIO_CONCENTRATION] = "concentration",
83 	[IIO_RESISTANCE] = "resistance",
84 	[IIO_PH] = "ph",
85 	[IIO_UVINDEX] = "uvindex",
86 	[IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
87 	[IIO_COUNT] = "count",
88 	[IIO_INDEX] = "index",
89 	[IIO_GRAVITY]  = "gravity",
90 	[IIO_POSITIONRELATIVE]  = "positionrelative",
91 	[IIO_PHASE] = "phase",
92 	[IIO_MASSCONCENTRATION] = "massconcentration",
93 	[IIO_DELTA_ANGL] = "deltaangl",
94 	[IIO_DELTA_VELOCITY] = "deltavelocity",
95 	[IIO_COLORTEMP] = "colortemp",
96 	[IIO_CHROMATICITY] = "chromaticity",
97 };
98 
99 static const char * const iio_modifier_names[] = {
100 	[IIO_MOD_X] = "x",
101 	[IIO_MOD_Y] = "y",
102 	[IIO_MOD_Z] = "z",
103 	[IIO_MOD_X_AND_Y] = "x&y",
104 	[IIO_MOD_X_AND_Z] = "x&z",
105 	[IIO_MOD_Y_AND_Z] = "y&z",
106 	[IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
107 	[IIO_MOD_X_OR_Y] = "x|y",
108 	[IIO_MOD_X_OR_Z] = "x|z",
109 	[IIO_MOD_Y_OR_Z] = "y|z",
110 	[IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
111 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
112 	[IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
113 	[IIO_MOD_LIGHT_BOTH] = "both",
114 	[IIO_MOD_LIGHT_IR] = "ir",
115 	[IIO_MOD_LIGHT_CLEAR] = "clear",
116 	[IIO_MOD_LIGHT_RED] = "red",
117 	[IIO_MOD_LIGHT_GREEN] = "green",
118 	[IIO_MOD_LIGHT_BLUE] = "blue",
119 	[IIO_MOD_LIGHT_UV] = "uv",
120 	[IIO_MOD_LIGHT_UVA] = "uva",
121 	[IIO_MOD_LIGHT_UVB] = "uvb",
122 	[IIO_MOD_LIGHT_DUV] = "duv",
123 	[IIO_MOD_QUATERNION] = "quaternion",
124 	[IIO_MOD_TEMP_AMBIENT] = "ambient",
125 	[IIO_MOD_TEMP_OBJECT] = "object",
126 	[IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
127 	[IIO_MOD_NORTH_TRUE] = "from_north_true",
128 	[IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
129 	[IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
130 	[IIO_MOD_RUNNING] = "running",
131 	[IIO_MOD_JOGGING] = "jogging",
132 	[IIO_MOD_WALKING] = "walking",
133 	[IIO_MOD_STILL] = "still",
134 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
135 	[IIO_MOD_I] = "i",
136 	[IIO_MOD_Q] = "q",
137 	[IIO_MOD_CO2] = "co2",
138 	[IIO_MOD_VOC] = "voc",
139 	[IIO_MOD_PM1] = "pm1",
140 	[IIO_MOD_PM2P5] = "pm2p5",
141 	[IIO_MOD_PM4] = "pm4",
142 	[IIO_MOD_PM10] = "pm10",
143 	[IIO_MOD_ETHANOL] = "ethanol",
144 	[IIO_MOD_H2] = "h2",
145 	[IIO_MOD_O2] = "o2",
146 	[IIO_MOD_LINEAR_X] = "linear_x",
147 	[IIO_MOD_LINEAR_Y] = "linear_y",
148 	[IIO_MOD_LINEAR_Z] = "linear_z",
149 	[IIO_MOD_PITCH] = "pitch",
150 	[IIO_MOD_YAW] = "yaw",
151 	[IIO_MOD_ROLL] = "roll",
152 };
153 
154 /* relies on pairs of these shared then separate */
155 static const char * const iio_chan_info_postfix[] = {
156 	[IIO_CHAN_INFO_RAW] = "raw",
157 	[IIO_CHAN_INFO_PROCESSED] = "input",
158 	[IIO_CHAN_INFO_SCALE] = "scale",
159 	[IIO_CHAN_INFO_OFFSET] = "offset",
160 	[IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
161 	[IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
162 	[IIO_CHAN_INFO_PEAK] = "peak_raw",
163 	[IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
164 	[IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
165 	[IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
166 	[IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
167 	= "filter_low_pass_3db_frequency",
168 	[IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
169 	= "filter_high_pass_3db_frequency",
170 	[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
171 	[IIO_CHAN_INFO_FREQUENCY] = "frequency",
172 	[IIO_CHAN_INFO_PHASE] = "phase",
173 	[IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
174 	[IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
175 	[IIO_CHAN_INFO_HYSTERESIS_RELATIVE] = "hysteresis_relative",
176 	[IIO_CHAN_INFO_INT_TIME] = "integration_time",
177 	[IIO_CHAN_INFO_ENABLE] = "en",
178 	[IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
179 	[IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
180 	[IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
181 	[IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
182 	[IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
183 	[IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
184 	[IIO_CHAN_INFO_THERMOCOUPLE_TYPE] = "thermocouple_type",
185 	[IIO_CHAN_INFO_CALIBAMBIENT] = "calibambient",
186 	[IIO_CHAN_INFO_ZEROPOINT] = "zeropoint",
187 	[IIO_CHAN_INFO_TROUGH] = "trough_raw",
188 };
189 /**
190  * iio_device_id() - query the unique ID for the device
191  * @indio_dev:		Device structure whose ID is being queried
192  *
193  * The IIO device ID is a unique index used for example for the naming
194  * of the character device /dev/iio\:device[ID].
195  *
196  * Returns: Unique ID for the device.
197  */
198 int iio_device_id(struct iio_dev *indio_dev)
199 {
200 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
201 
202 	return iio_dev_opaque->id;
203 }
204 EXPORT_SYMBOL_GPL(iio_device_id);
205 
206 /**
207  * iio_buffer_enabled() - helper function to test if the buffer is enabled
208  * @indio_dev:		IIO device structure for device
209  *
210  * Returns: True, if the buffer is enabled.
211  */
212 bool iio_buffer_enabled(struct iio_dev *indio_dev)
213 {
214 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
215 
216 	return iio_dev_opaque->currentmode &
217 	       (INDIO_BUFFER_HARDWARE | INDIO_BUFFER_SOFTWARE |
218 		INDIO_BUFFER_TRIGGERED);
219 }
220 EXPORT_SYMBOL_GPL(iio_buffer_enabled);
221 
222 #if defined(CONFIG_DEBUG_FS)
223 /*
224  * There's also a CONFIG_DEBUG_FS guard in include/linux/iio/iio.h for
225  * iio_get_debugfs_dentry() to make it inline if CONFIG_DEBUG_FS is undefined
226  */
227 struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
228 {
229 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
230 
231 	return iio_dev_opaque->debugfs_dentry;
232 }
233 EXPORT_SYMBOL_GPL(iio_get_debugfs_dentry);
234 #endif
235 
236 /**
237  * iio_find_channel_from_si() - get channel from its scan index
238  * @indio_dev:		device
239  * @si:			scan index to match
240  *
241  * Returns:
242  * Constant pointer to iio_chan_spec, if scan index matches, NULL on failure.
243  */
244 const struct iio_chan_spec
245 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
246 {
247 	int i;
248 
249 	for (i = 0; i < indio_dev->num_channels; i++)
250 		if (indio_dev->channels[i].scan_index == si)
251 			return &indio_dev->channels[i];
252 	return NULL;
253 }
254 
255 /* This turns up an awful lot */
256 ssize_t iio_read_const_attr(struct device *dev,
257 			    struct device_attribute *attr,
258 			    char *buf)
259 {
260 	return sysfs_emit(buf, "%s\n", to_iio_const_attr(attr)->string);
261 }
262 EXPORT_SYMBOL(iio_read_const_attr);
263 
264 /**
265  * iio_device_set_clock() - Set current timestamping clock for the device
266  * @indio_dev: IIO device structure containing the device
267  * @clock_id: timestamping clock POSIX identifier to set.
268  *
269  * Returns: 0 on success, or a negative error code.
270  */
271 int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
272 {
273 	int ret;
274 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
275 	const struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
276 
277 	ret = mutex_lock_interruptible(&iio_dev_opaque->mlock);
278 	if (ret)
279 		return ret;
280 	if ((ev_int && iio_event_enabled(ev_int)) ||
281 	    iio_buffer_enabled(indio_dev)) {
282 		mutex_unlock(&iio_dev_opaque->mlock);
283 		return -EBUSY;
284 	}
285 	iio_dev_opaque->clock_id = clock_id;
286 	mutex_unlock(&iio_dev_opaque->mlock);
287 
288 	return 0;
289 }
290 EXPORT_SYMBOL(iio_device_set_clock);
291 
292 /**
293  * iio_device_get_clock() - Retrieve current timestamping clock for the device
294  * @indio_dev: IIO device structure containing the device
295  *
296  * Returns: Clock ID of the current timestamping clock for the device.
297  */
298 clockid_t iio_device_get_clock(const struct iio_dev *indio_dev)
299 {
300 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
301 
302 	return iio_dev_opaque->clock_id;
303 }
304 EXPORT_SYMBOL(iio_device_get_clock);
305 
306 /**
307  * iio_get_time_ns() - utility function to get a time stamp for events etc
308  * @indio_dev: device
309  *
310  * Returns: Timestamp of the event in nanoseconds.
311  */
312 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
313 {
314 	struct timespec64 tp;
315 
316 	switch (iio_device_get_clock(indio_dev)) {
317 	case CLOCK_REALTIME:
318 		return ktime_get_real_ns();
319 	case CLOCK_MONOTONIC:
320 		return ktime_get_ns();
321 	case CLOCK_MONOTONIC_RAW:
322 		return ktime_get_raw_ns();
323 	case CLOCK_REALTIME_COARSE:
324 		return ktime_to_ns(ktime_get_coarse_real());
325 	case CLOCK_MONOTONIC_COARSE:
326 		ktime_get_coarse_ts64(&tp);
327 		return timespec64_to_ns(&tp);
328 	case CLOCK_BOOTTIME:
329 		return ktime_get_boottime_ns();
330 	case CLOCK_TAI:
331 		return ktime_get_clocktai_ns();
332 	default:
333 		BUG();
334 	}
335 }
336 EXPORT_SYMBOL(iio_get_time_ns);
337 
338 static int __init iio_init(void)
339 {
340 	int ret;
341 
342 	/* Register sysfs bus */
343 	ret  = bus_register(&iio_bus_type);
344 	if (ret < 0) {
345 		pr_err("could not register bus type\n");
346 		goto error_nothing;
347 	}
348 
349 	ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
350 	if (ret < 0) {
351 		pr_err("failed to allocate char dev region\n");
352 		goto error_unregister_bus_type;
353 	}
354 
355 	iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
356 
357 	return 0;
358 
359 error_unregister_bus_type:
360 	bus_unregister(&iio_bus_type);
361 error_nothing:
362 	return ret;
363 }
364 
365 static void __exit iio_exit(void)
366 {
367 	if (iio_devt)
368 		unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
369 	bus_unregister(&iio_bus_type);
370 	debugfs_remove(iio_debugfs_dentry);
371 }
372 
373 #if defined(CONFIG_DEBUG_FS)
374 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
375 			      size_t count, loff_t *ppos)
376 {
377 	struct iio_dev *indio_dev = file->private_data;
378 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
379 	unsigned int val = 0;
380 	int ret;
381 
382 	if (*ppos > 0)
383 		return simple_read_from_buffer(userbuf, count, ppos,
384 					       iio_dev_opaque->read_buf,
385 					       iio_dev_opaque->read_buf_len);
386 
387 	ret = indio_dev->info->debugfs_reg_access(indio_dev,
388 						  iio_dev_opaque->cached_reg_addr,
389 						  0, &val);
390 	if (ret) {
391 		dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
392 		return ret;
393 	}
394 
395 	iio_dev_opaque->read_buf_len = snprintf(iio_dev_opaque->read_buf,
396 						sizeof(iio_dev_opaque->read_buf),
397 						"0x%X\n", val);
398 
399 	return simple_read_from_buffer(userbuf, count, ppos,
400 				       iio_dev_opaque->read_buf,
401 				       iio_dev_opaque->read_buf_len);
402 }
403 
404 static ssize_t iio_debugfs_write_reg(struct file *file,
405 		     const char __user *userbuf, size_t count, loff_t *ppos)
406 {
407 	struct iio_dev *indio_dev = file->private_data;
408 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
409 	unsigned int reg, val;
410 	char buf[80];
411 	int ret;
412 
413 	count = min(count, sizeof(buf) - 1);
414 	if (copy_from_user(buf, userbuf, count))
415 		return -EFAULT;
416 
417 	buf[count] = 0;
418 
419 	ret = sscanf(buf, "%i %i", &reg, &val);
420 
421 	switch (ret) {
422 	case 1:
423 		iio_dev_opaque->cached_reg_addr = reg;
424 		break;
425 	case 2:
426 		iio_dev_opaque->cached_reg_addr = reg;
427 		ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
428 							  val, NULL);
429 		if (ret) {
430 			dev_err(indio_dev->dev.parent, "%s: write failed\n",
431 				__func__);
432 			return ret;
433 		}
434 		break;
435 	default:
436 		return -EINVAL;
437 	}
438 
439 	return count;
440 }
441 
442 static const struct file_operations iio_debugfs_reg_fops = {
443 	.open = simple_open,
444 	.read = iio_debugfs_read_reg,
445 	.write = iio_debugfs_write_reg,
446 };
447 
448 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
449 {
450 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
451 
452 	debugfs_remove_recursive(iio_dev_opaque->debugfs_dentry);
453 }
454 
455 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
456 {
457 	struct iio_dev_opaque *iio_dev_opaque;
458 
459 	if (indio_dev->info->debugfs_reg_access == NULL)
460 		return;
461 
462 	if (!iio_debugfs_dentry)
463 		return;
464 
465 	iio_dev_opaque = to_iio_dev_opaque(indio_dev);
466 
467 	iio_dev_opaque->debugfs_dentry =
468 		debugfs_create_dir(dev_name(&indio_dev->dev),
469 				   iio_debugfs_dentry);
470 
471 	debugfs_create_file("direct_reg_access", 0644,
472 			    iio_dev_opaque->debugfs_dentry, indio_dev,
473 			    &iio_debugfs_reg_fops);
474 }
475 #else
476 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
477 {
478 }
479 
480 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
481 {
482 }
483 #endif /* CONFIG_DEBUG_FS */
484 
485 static ssize_t iio_read_channel_ext_info(struct device *dev,
486 				     struct device_attribute *attr,
487 				     char *buf)
488 {
489 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
490 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
491 	const struct iio_chan_spec_ext_info *ext_info;
492 
493 	ext_info = &this_attr->c->ext_info[this_attr->address];
494 
495 	return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
496 }
497 
498 static ssize_t iio_write_channel_ext_info(struct device *dev,
499 				     struct device_attribute *attr,
500 				     const char *buf, size_t len)
501 {
502 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
503 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
504 	const struct iio_chan_spec_ext_info *ext_info;
505 
506 	ext_info = &this_attr->c->ext_info[this_attr->address];
507 
508 	return ext_info->write(indio_dev, ext_info->private,
509 			       this_attr->c, buf, len);
510 }
511 
512 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
513 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
514 {
515 	const struct iio_enum *e = (const struct iio_enum *)priv;
516 	unsigned int i;
517 	size_t len = 0;
518 
519 	if (!e->num_items)
520 		return 0;
521 
522 	for (i = 0; i < e->num_items; ++i) {
523 		if (!e->items[i])
524 			continue;
525 		len += sysfs_emit_at(buf, len, "%s ", e->items[i]);
526 	}
527 
528 	/* replace last space with a newline */
529 	buf[len - 1] = '\n';
530 
531 	return len;
532 }
533 EXPORT_SYMBOL_GPL(iio_enum_available_read);
534 
535 ssize_t iio_enum_read(struct iio_dev *indio_dev,
536 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
537 {
538 	const struct iio_enum *e = (const struct iio_enum *)priv;
539 	int i;
540 
541 	if (!e->get)
542 		return -EINVAL;
543 
544 	i = e->get(indio_dev, chan);
545 	if (i < 0)
546 		return i;
547 	if (i >= e->num_items || !e->items[i])
548 		return -EINVAL;
549 
550 	return sysfs_emit(buf, "%s\n", e->items[i]);
551 }
552 EXPORT_SYMBOL_GPL(iio_enum_read);
553 
554 ssize_t iio_enum_write(struct iio_dev *indio_dev,
555 	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
556 	size_t len)
557 {
558 	const struct iio_enum *e = (const struct iio_enum *)priv;
559 	int ret;
560 
561 	if (!e->set)
562 		return -EINVAL;
563 
564 	ret = __sysfs_match_string(e->items, e->num_items, buf);
565 	if (ret < 0)
566 		return ret;
567 
568 	ret = e->set(indio_dev, chan, ret);
569 	return ret ? ret : len;
570 }
571 EXPORT_SYMBOL_GPL(iio_enum_write);
572 
573 static const struct iio_mount_matrix iio_mount_idmatrix = {
574 	.rotation = {
575 		"1", "0", "0",
576 		"0", "1", "0",
577 		"0", "0", "1"
578 	}
579 };
580 
581 static int iio_setup_mount_idmatrix(const struct device *dev,
582 				    struct iio_mount_matrix *matrix)
583 {
584 	*matrix = iio_mount_idmatrix;
585 	dev_info(dev, "mounting matrix not found: using identity...\n");
586 	return 0;
587 }
588 
589 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
590 			      const struct iio_chan_spec *chan, char *buf)
591 {
592 	const struct iio_mount_matrix *mtx;
593 
594 	mtx = ((iio_get_mount_matrix_t *)priv)(indio_dev, chan);
595 	if (IS_ERR(mtx))
596 		return PTR_ERR(mtx);
597 
598 	if (!mtx)
599 		mtx = &iio_mount_idmatrix;
600 
601 	return sysfs_emit(buf, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
602 			  mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
603 			  mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
604 			  mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
605 }
606 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
607 
608 /**
609  * iio_read_mount_matrix() - retrieve iio device mounting matrix from
610  *                           device "mount-matrix" property
611  * @dev:	device the mounting matrix property is assigned to
612  * @matrix:	where to store retrieved matrix
613  *
614  * If device is assigned no mounting matrix property, a default 3x3 identity
615  * matrix will be filled in.
616  *
617  * Returns: 0 if success, or a negative error code on failure.
618  */
619 int iio_read_mount_matrix(struct device *dev, struct iio_mount_matrix *matrix)
620 {
621 	size_t len = ARRAY_SIZE(iio_mount_idmatrix.rotation);
622 	int err;
623 
624 	err = device_property_read_string_array(dev, "mount-matrix", matrix->rotation, len);
625 	if (err == len)
626 		return 0;
627 
628 	if (err >= 0)
629 		/* Invalid number of matrix entries. */
630 		return -EINVAL;
631 
632 	if (err != -EINVAL)
633 		/* Invalid matrix declaration format. */
634 		return err;
635 
636 	/* Matrix was not declared at all: fallback to identity. */
637 	return iio_setup_mount_idmatrix(dev, matrix);
638 }
639 EXPORT_SYMBOL(iio_read_mount_matrix);
640 
641 static ssize_t __iio_format_value(char *buf, size_t offset, unsigned int type,
642 				  int size, const int *vals)
643 {
644 	int tmp0, tmp1;
645 	s64 tmp2;
646 	bool scale_db = false;
647 
648 	switch (type) {
649 	case IIO_VAL_INT:
650 		return sysfs_emit_at(buf, offset, "%d", vals[0]);
651 	case IIO_VAL_INT_PLUS_MICRO_DB:
652 		scale_db = true;
653 		fallthrough;
654 	case IIO_VAL_INT_PLUS_MICRO:
655 		if (vals[1] < 0)
656 			return sysfs_emit_at(buf, offset, "-%d.%06u%s",
657 					     abs(vals[0]), -vals[1],
658 					     scale_db ? " dB" : "");
659 		else
660 			return sysfs_emit_at(buf, offset, "%d.%06u%s", vals[0],
661 					     vals[1], scale_db ? " dB" : "");
662 	case IIO_VAL_INT_PLUS_NANO:
663 		if (vals[1] < 0)
664 			return sysfs_emit_at(buf, offset, "-%d.%09u",
665 					     abs(vals[0]), -vals[1]);
666 		else
667 			return sysfs_emit_at(buf, offset, "%d.%09u", vals[0],
668 					     vals[1]);
669 	case IIO_VAL_FRACTIONAL:
670 		tmp2 = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
671 		tmp1 = vals[1];
672 		tmp0 = (int)div_s64_rem(tmp2, 1000000000, &tmp1);
673 		if ((tmp2 < 0) && (tmp0 == 0))
674 			return sysfs_emit_at(buf, offset, "-0.%09u", abs(tmp1));
675 		else
676 			return sysfs_emit_at(buf, offset, "%d.%09u", tmp0,
677 					     abs(tmp1));
678 	case IIO_VAL_FRACTIONAL_LOG2:
679 		tmp2 = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
680 		tmp0 = (int)div_s64_rem(tmp2, 1000000000LL, &tmp1);
681 		if (tmp0 == 0 && tmp2 < 0)
682 			return sysfs_emit_at(buf, offset, "-0.%09u", abs(tmp1));
683 		else
684 			return sysfs_emit_at(buf, offset, "%d.%09u", tmp0,
685 					     abs(tmp1));
686 	case IIO_VAL_INT_MULTIPLE:
687 	{
688 		int i;
689 		int l = 0;
690 
691 		for (i = 0; i < size; ++i)
692 			l += sysfs_emit_at(buf, offset + l, "%d ", vals[i]);
693 		return l;
694 	}
695 	case IIO_VAL_CHAR:
696 		return sysfs_emit_at(buf, offset, "%c", (char)vals[0]);
697 	case IIO_VAL_INT_64:
698 		tmp2 = (s64)((((u64)vals[1]) << 32) | (u32)vals[0]);
699 		return sysfs_emit_at(buf, offset, "%lld", tmp2);
700 	default:
701 		return 0;
702 	}
703 }
704 
705 /**
706  * iio_format_value() - Formats a IIO value into its string representation
707  * @buf:	The buffer to which the formatted value gets written
708  *		which is assumed to be big enough (i.e. PAGE_SIZE).
709  * @type:	One of the IIO_VAL_* constants. This decides how the val
710  *		and val2 parameters are formatted.
711  * @size:	Number of IIO value entries contained in vals
712  * @vals:	Pointer to the values, exact meaning depends on the
713  *		type parameter.
714  *
715  * Returns:
716  * 0 by default, a negative number on failure or the total number of characters
717  * written for a type that belongs to the IIO_VAL_* constant.
718  */
719 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
720 {
721 	ssize_t len;
722 
723 	len = __iio_format_value(buf, 0, type, size, vals);
724 	if (len >= PAGE_SIZE - 1)
725 		return -EFBIG;
726 
727 	return len + sysfs_emit_at(buf, len, "\n");
728 }
729 EXPORT_SYMBOL_GPL(iio_format_value);
730 
731 static ssize_t iio_read_channel_label(struct device *dev,
732 				      struct device_attribute *attr,
733 				      char *buf)
734 {
735 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
736 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
737 
738 	if (indio_dev->info->read_label)
739 		return indio_dev->info->read_label(indio_dev, this_attr->c, buf);
740 
741 	if (this_attr->c->extend_name)
742 		return sysfs_emit(buf, "%s\n", this_attr->c->extend_name);
743 
744 	return -EINVAL;
745 }
746 
747 static ssize_t iio_read_channel_info(struct device *dev,
748 				     struct device_attribute *attr,
749 				     char *buf)
750 {
751 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
752 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
753 	int vals[INDIO_MAX_RAW_ELEMENTS];
754 	int ret;
755 	int val_len = 2;
756 
757 	if (indio_dev->info->read_raw_multi)
758 		ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
759 							INDIO_MAX_RAW_ELEMENTS,
760 							vals, &val_len,
761 							this_attr->address);
762 	else
763 		ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
764 				    &vals[0], &vals[1], this_attr->address);
765 
766 	if (ret < 0)
767 		return ret;
768 
769 	return iio_format_value(buf, ret, val_len, vals);
770 }
771 
772 static ssize_t iio_format_list(char *buf, const int *vals, int type, int length,
773 			       const char *prefix, const char *suffix)
774 {
775 	ssize_t len;
776 	int stride;
777 	int i;
778 
779 	switch (type) {
780 	case IIO_VAL_INT:
781 		stride = 1;
782 		break;
783 	default:
784 		stride = 2;
785 		break;
786 	}
787 
788 	len = sysfs_emit(buf, prefix);
789 
790 	for (i = 0; i <= length - stride; i += stride) {
791 		if (i != 0) {
792 			len += sysfs_emit_at(buf, len, " ");
793 			if (len >= PAGE_SIZE)
794 				return -EFBIG;
795 		}
796 
797 		len += __iio_format_value(buf, len, type, stride, &vals[i]);
798 		if (len >= PAGE_SIZE)
799 			return -EFBIG;
800 	}
801 
802 	len += sysfs_emit_at(buf, len, "%s\n", suffix);
803 
804 	return len;
805 }
806 
807 static ssize_t iio_format_avail_list(char *buf, const int *vals,
808 				     int type, int length)
809 {
810 
811 	return iio_format_list(buf, vals, type, length, "", "");
812 }
813 
814 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
815 {
816 	int length;
817 
818 	/*
819 	 * length refers to the array size , not the number of elements.
820 	 * The purpose is to print the range [min , step ,max] so length should
821 	 * be 3 in case of int, and 6 for other types.
822 	 */
823 	switch (type) {
824 	case IIO_VAL_INT:
825 		length = 3;
826 		break;
827 	default:
828 		length = 6;
829 		break;
830 	}
831 
832 	return iio_format_list(buf, vals, type, length, "[", "]");
833 }
834 
835 static ssize_t iio_read_channel_info_avail(struct device *dev,
836 					   struct device_attribute *attr,
837 					   char *buf)
838 {
839 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
840 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
841 	const int *vals;
842 	int ret;
843 	int length;
844 	int type;
845 
846 	ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
847 					  &vals, &type, &length,
848 					  this_attr->address);
849 
850 	if (ret < 0)
851 		return ret;
852 	switch (ret) {
853 	case IIO_AVAIL_LIST:
854 		return iio_format_avail_list(buf, vals, type, length);
855 	case IIO_AVAIL_RANGE:
856 		return iio_format_avail_range(buf, vals, type);
857 	default:
858 		return -EINVAL;
859 	}
860 }
861 
862 /**
863  * __iio_str_to_fixpoint() - Parse a fixed-point number from a string
864  * @str: The string to parse
865  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
866  * @integer: The integer part of the number
867  * @fract: The fractional part of the number
868  * @scale_db: True if this should parse as dB
869  *
870  * Returns:
871  * 0 on success, or a negative error code if the string could not be parsed.
872  */
873 static int __iio_str_to_fixpoint(const char *str, int fract_mult,
874 				 int *integer, int *fract, bool scale_db)
875 {
876 	int i = 0, f = 0;
877 	bool integer_part = true, negative = false;
878 
879 	if (fract_mult == 0) {
880 		*fract = 0;
881 
882 		return kstrtoint(str, 0, integer);
883 	}
884 
885 	if (str[0] == '-') {
886 		negative = true;
887 		str++;
888 	} else if (str[0] == '+') {
889 		str++;
890 	}
891 
892 	while (*str) {
893 		if ('0' <= *str && *str <= '9') {
894 			if (integer_part) {
895 				i = i * 10 + *str - '0';
896 			} else {
897 				f += fract_mult * (*str - '0');
898 				fract_mult /= 10;
899 			}
900 		} else if (*str == '\n') {
901 			if (*(str + 1) == '\0')
902 				break;
903 			return -EINVAL;
904 		} else if (!strncmp(str, " dB", sizeof(" dB") - 1) && scale_db) {
905 			/* Ignore the dB suffix */
906 			str += sizeof(" dB") - 1;
907 			continue;
908 		} else if (!strncmp(str, "dB", sizeof("dB") - 1) && scale_db) {
909 			/* Ignore the dB suffix */
910 			str += sizeof("dB") - 1;
911 			continue;
912 		} else if (*str == '.' && integer_part) {
913 			integer_part = false;
914 		} else {
915 			return -EINVAL;
916 		}
917 		str++;
918 	}
919 
920 	if (negative) {
921 		if (i)
922 			i = -i;
923 		else
924 			f = -f;
925 	}
926 
927 	*integer = i;
928 	*fract = f;
929 
930 	return 0;
931 }
932 
933 /**
934  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
935  * @str: The string to parse
936  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
937  * @integer: The integer part of the number
938  * @fract: The fractional part of the number
939  *
940  * Returns:
941  * 0 on success, or a negative error code if the string could not be parsed.
942  */
943 int iio_str_to_fixpoint(const char *str, int fract_mult,
944 			int *integer, int *fract)
945 {
946 	return __iio_str_to_fixpoint(str, fract_mult, integer, fract, false);
947 }
948 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
949 
950 static ssize_t iio_write_channel_info(struct device *dev,
951 				      struct device_attribute *attr,
952 				      const char *buf,
953 				      size_t len)
954 {
955 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
956 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
957 	int ret, fract_mult = 100000;
958 	int integer, fract = 0;
959 	bool is_char = false;
960 	bool scale_db = false;
961 
962 	/* Assumes decimal - precision based on number of digits */
963 	if (!indio_dev->info->write_raw)
964 		return -EINVAL;
965 
966 	if (indio_dev->info->write_raw_get_fmt)
967 		switch (indio_dev->info->write_raw_get_fmt(indio_dev,
968 			this_attr->c, this_attr->address)) {
969 		case IIO_VAL_INT:
970 			fract_mult = 0;
971 			break;
972 		case IIO_VAL_INT_PLUS_MICRO_DB:
973 			scale_db = true;
974 			fallthrough;
975 		case IIO_VAL_INT_PLUS_MICRO:
976 			fract_mult = 100000;
977 			break;
978 		case IIO_VAL_INT_PLUS_NANO:
979 			fract_mult = 100000000;
980 			break;
981 		case IIO_VAL_CHAR:
982 			is_char = true;
983 			break;
984 		default:
985 			return -EINVAL;
986 		}
987 
988 	if (is_char) {
989 		char ch;
990 
991 		if (sscanf(buf, "%c", &ch) != 1)
992 			return -EINVAL;
993 		integer = ch;
994 	} else {
995 		ret = __iio_str_to_fixpoint(buf, fract_mult, &integer, &fract,
996 					    scale_db);
997 		if (ret)
998 			return ret;
999 	}
1000 
1001 	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
1002 					 integer, fract, this_attr->address);
1003 	if (ret)
1004 		return ret;
1005 
1006 	return len;
1007 }
1008 
1009 static
1010 int __iio_device_attr_init(struct device_attribute *dev_attr,
1011 			   const char *postfix,
1012 			   struct iio_chan_spec const *chan,
1013 			   ssize_t (*readfunc)(struct device *dev,
1014 					       struct device_attribute *attr,
1015 					       char *buf),
1016 			   ssize_t (*writefunc)(struct device *dev,
1017 						struct device_attribute *attr,
1018 						const char *buf,
1019 						size_t len),
1020 			   enum iio_shared_by shared_by)
1021 {
1022 	int ret = 0;
1023 	char *name = NULL;
1024 	char *full_postfix;
1025 
1026 	sysfs_attr_init(&dev_attr->attr);
1027 
1028 	/* Build up postfix of <extend_name>_<modifier>_postfix */
1029 	if (chan->modified && (shared_by == IIO_SEPARATE)) {
1030 		if (chan->extend_name)
1031 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
1032 						 iio_modifier_names[chan->channel2],
1033 						 chan->extend_name,
1034 						 postfix);
1035 		else
1036 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
1037 						 iio_modifier_names[chan->channel2],
1038 						 postfix);
1039 	} else {
1040 		if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
1041 			full_postfix = kstrdup(postfix, GFP_KERNEL);
1042 		else
1043 			full_postfix = kasprintf(GFP_KERNEL,
1044 						 "%s_%s",
1045 						 chan->extend_name,
1046 						 postfix);
1047 	}
1048 	if (full_postfix == NULL)
1049 		return -ENOMEM;
1050 
1051 	if (chan->differential) { /* Differential can not have modifier */
1052 		switch (shared_by) {
1053 		case IIO_SHARED_BY_ALL:
1054 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
1055 			break;
1056 		case IIO_SHARED_BY_DIR:
1057 			name = kasprintf(GFP_KERNEL, "%s_%s",
1058 						iio_direction[chan->output],
1059 						full_postfix);
1060 			break;
1061 		case IIO_SHARED_BY_TYPE:
1062 			name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
1063 					    iio_direction[chan->output],
1064 					    iio_chan_type_name_spec[chan->type],
1065 					    iio_chan_type_name_spec[chan->type],
1066 					    full_postfix);
1067 			break;
1068 		case IIO_SEPARATE:
1069 			if (!chan->indexed) {
1070 				WARN(1, "Differential channels must be indexed\n");
1071 				ret = -EINVAL;
1072 				goto error_free_full_postfix;
1073 			}
1074 			name = kasprintf(GFP_KERNEL,
1075 					    "%s_%s%d-%s%d_%s",
1076 					    iio_direction[chan->output],
1077 					    iio_chan_type_name_spec[chan->type],
1078 					    chan->channel,
1079 					    iio_chan_type_name_spec[chan->type],
1080 					    chan->channel2,
1081 					    full_postfix);
1082 			break;
1083 		}
1084 	} else { /* Single ended */
1085 		switch (shared_by) {
1086 		case IIO_SHARED_BY_ALL:
1087 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
1088 			break;
1089 		case IIO_SHARED_BY_DIR:
1090 			name = kasprintf(GFP_KERNEL, "%s_%s",
1091 						iio_direction[chan->output],
1092 						full_postfix);
1093 			break;
1094 		case IIO_SHARED_BY_TYPE:
1095 			name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1096 					    iio_direction[chan->output],
1097 					    iio_chan_type_name_spec[chan->type],
1098 					    full_postfix);
1099 			break;
1100 
1101 		case IIO_SEPARATE:
1102 			if (chan->indexed)
1103 				name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
1104 						    iio_direction[chan->output],
1105 						    iio_chan_type_name_spec[chan->type],
1106 						    chan->channel,
1107 						    full_postfix);
1108 			else
1109 				name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1110 						    iio_direction[chan->output],
1111 						    iio_chan_type_name_spec[chan->type],
1112 						    full_postfix);
1113 			break;
1114 		}
1115 	}
1116 	if (name == NULL) {
1117 		ret = -ENOMEM;
1118 		goto error_free_full_postfix;
1119 	}
1120 	dev_attr->attr.name = name;
1121 
1122 	if (readfunc) {
1123 		dev_attr->attr.mode |= 0444;
1124 		dev_attr->show = readfunc;
1125 	}
1126 
1127 	if (writefunc) {
1128 		dev_attr->attr.mode |= 0200;
1129 		dev_attr->store = writefunc;
1130 	}
1131 
1132 error_free_full_postfix:
1133 	kfree(full_postfix);
1134 
1135 	return ret;
1136 }
1137 
1138 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1139 {
1140 	kfree(dev_attr->attr.name);
1141 }
1142 
1143 int __iio_add_chan_devattr(const char *postfix,
1144 			   struct iio_chan_spec const *chan,
1145 			   ssize_t (*readfunc)(struct device *dev,
1146 					       struct device_attribute *attr,
1147 					       char *buf),
1148 			   ssize_t (*writefunc)(struct device *dev,
1149 						struct device_attribute *attr,
1150 						const char *buf,
1151 						size_t len),
1152 			   u64 mask,
1153 			   enum iio_shared_by shared_by,
1154 			   struct device *dev,
1155 			   struct iio_buffer *buffer,
1156 			   struct list_head *attr_list)
1157 {
1158 	int ret;
1159 	struct iio_dev_attr *iio_attr, *t;
1160 
1161 	iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1162 	if (iio_attr == NULL)
1163 		return -ENOMEM;
1164 	ret = __iio_device_attr_init(&iio_attr->dev_attr,
1165 				     postfix, chan,
1166 				     readfunc, writefunc, shared_by);
1167 	if (ret)
1168 		goto error_iio_dev_attr_free;
1169 	iio_attr->c = chan;
1170 	iio_attr->address = mask;
1171 	iio_attr->buffer = buffer;
1172 	list_for_each_entry(t, attr_list, l)
1173 		if (strcmp(t->dev_attr.attr.name,
1174 			   iio_attr->dev_attr.attr.name) == 0) {
1175 			if (shared_by == IIO_SEPARATE)
1176 				dev_err(dev, "tried to double register : %s\n",
1177 					t->dev_attr.attr.name);
1178 			ret = -EBUSY;
1179 			goto error_device_attr_deinit;
1180 		}
1181 	list_add(&iio_attr->l, attr_list);
1182 
1183 	return 0;
1184 
1185 error_device_attr_deinit:
1186 	__iio_device_attr_deinit(&iio_attr->dev_attr);
1187 error_iio_dev_attr_free:
1188 	kfree(iio_attr);
1189 	return ret;
1190 }
1191 
1192 static int iio_device_add_channel_label(struct iio_dev *indio_dev,
1193 					 struct iio_chan_spec const *chan)
1194 {
1195 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1196 	int ret;
1197 
1198 	if (!indio_dev->info->read_label && !chan->extend_name)
1199 		return 0;
1200 
1201 	ret = __iio_add_chan_devattr("label",
1202 				     chan,
1203 				     &iio_read_channel_label,
1204 				     NULL,
1205 				     0,
1206 				     IIO_SEPARATE,
1207 				     &indio_dev->dev,
1208 				     NULL,
1209 				     &iio_dev_opaque->channel_attr_list);
1210 	if (ret < 0)
1211 		return ret;
1212 
1213 	return 1;
1214 }
1215 
1216 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1217 					 struct iio_chan_spec const *chan,
1218 					 enum iio_shared_by shared_by,
1219 					 const long *infomask)
1220 {
1221 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1222 	int i, ret, attrcount = 0;
1223 
1224 	for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1225 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1226 			return -EINVAL;
1227 		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1228 					     chan,
1229 					     &iio_read_channel_info,
1230 					     &iio_write_channel_info,
1231 					     i,
1232 					     shared_by,
1233 					     &indio_dev->dev,
1234 					     NULL,
1235 					     &iio_dev_opaque->channel_attr_list);
1236 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1237 			continue;
1238 		if (ret < 0)
1239 			return ret;
1240 		attrcount++;
1241 	}
1242 
1243 	return attrcount;
1244 }
1245 
1246 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1247 					       struct iio_chan_spec const *chan,
1248 					       enum iio_shared_by shared_by,
1249 					       const long *infomask)
1250 {
1251 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1252 	int i, ret, attrcount = 0;
1253 	char *avail_postfix;
1254 
1255 	for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1256 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1257 			return -EINVAL;
1258 		avail_postfix = kasprintf(GFP_KERNEL,
1259 					  "%s_available",
1260 					  iio_chan_info_postfix[i]);
1261 		if (!avail_postfix)
1262 			return -ENOMEM;
1263 
1264 		ret = __iio_add_chan_devattr(avail_postfix,
1265 					     chan,
1266 					     &iio_read_channel_info_avail,
1267 					     NULL,
1268 					     i,
1269 					     shared_by,
1270 					     &indio_dev->dev,
1271 					     NULL,
1272 					     &iio_dev_opaque->channel_attr_list);
1273 		kfree(avail_postfix);
1274 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1275 			continue;
1276 		if (ret < 0)
1277 			return ret;
1278 		attrcount++;
1279 	}
1280 
1281 	return attrcount;
1282 }
1283 
1284 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1285 					struct iio_chan_spec const *chan)
1286 {
1287 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1288 	int ret, attrcount = 0;
1289 	const struct iio_chan_spec_ext_info *ext_info;
1290 
1291 	if (chan->channel < 0)
1292 		return 0;
1293 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1294 					    IIO_SEPARATE,
1295 					    &chan->info_mask_separate);
1296 	if (ret < 0)
1297 		return ret;
1298 	attrcount += ret;
1299 
1300 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1301 						  IIO_SEPARATE,
1302 						  &chan->info_mask_separate_available);
1303 	if (ret < 0)
1304 		return ret;
1305 	attrcount += ret;
1306 
1307 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1308 					    IIO_SHARED_BY_TYPE,
1309 					    &chan->info_mask_shared_by_type);
1310 	if (ret < 0)
1311 		return ret;
1312 	attrcount += ret;
1313 
1314 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1315 						  IIO_SHARED_BY_TYPE,
1316 						  &chan->info_mask_shared_by_type_available);
1317 	if (ret < 0)
1318 		return ret;
1319 	attrcount += ret;
1320 
1321 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1322 					    IIO_SHARED_BY_DIR,
1323 					    &chan->info_mask_shared_by_dir);
1324 	if (ret < 0)
1325 		return ret;
1326 	attrcount += ret;
1327 
1328 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1329 						  IIO_SHARED_BY_DIR,
1330 						  &chan->info_mask_shared_by_dir_available);
1331 	if (ret < 0)
1332 		return ret;
1333 	attrcount += ret;
1334 
1335 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1336 					    IIO_SHARED_BY_ALL,
1337 					    &chan->info_mask_shared_by_all);
1338 	if (ret < 0)
1339 		return ret;
1340 	attrcount += ret;
1341 
1342 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1343 						  IIO_SHARED_BY_ALL,
1344 						  &chan->info_mask_shared_by_all_available);
1345 	if (ret < 0)
1346 		return ret;
1347 	attrcount += ret;
1348 
1349 	ret = iio_device_add_channel_label(indio_dev, chan);
1350 	if (ret < 0)
1351 		return ret;
1352 	attrcount += ret;
1353 
1354 	if (chan->ext_info) {
1355 		unsigned int i = 0;
1356 
1357 		for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1358 			ret = __iio_add_chan_devattr(ext_info->name,
1359 					chan,
1360 					ext_info->read ?
1361 					    &iio_read_channel_ext_info : NULL,
1362 					ext_info->write ?
1363 					    &iio_write_channel_ext_info : NULL,
1364 					i,
1365 					ext_info->shared,
1366 					&indio_dev->dev,
1367 					NULL,
1368 					&iio_dev_opaque->channel_attr_list);
1369 			i++;
1370 			if (ret == -EBUSY && ext_info->shared)
1371 				continue;
1372 
1373 			if (ret)
1374 				return ret;
1375 
1376 			attrcount++;
1377 		}
1378 	}
1379 
1380 	return attrcount;
1381 }
1382 
1383 /**
1384  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1385  * @attr_list: List of IIO device attributes
1386  *
1387  * This function frees the memory allocated for each of the IIO device
1388  * attributes in the list.
1389  */
1390 void iio_free_chan_devattr_list(struct list_head *attr_list)
1391 {
1392 	struct iio_dev_attr *p, *n;
1393 
1394 	list_for_each_entry_safe(p, n, attr_list, l) {
1395 		kfree_const(p->dev_attr.attr.name);
1396 		list_del(&p->l);
1397 		kfree(p);
1398 	}
1399 }
1400 
1401 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
1402 			 char *buf)
1403 {
1404 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1405 
1406 	return sysfs_emit(buf, "%s\n", indio_dev->name);
1407 }
1408 
1409 static DEVICE_ATTR_RO(name);
1410 
1411 static ssize_t label_show(struct device *dev, struct device_attribute *attr,
1412 			  char *buf)
1413 {
1414 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1415 
1416 	return sysfs_emit(buf, "%s\n", indio_dev->label);
1417 }
1418 
1419 static DEVICE_ATTR_RO(label);
1420 
1421 static const char * const clock_names[] = {
1422 	[CLOCK_REALTIME]	 	= "realtime",
1423 	[CLOCK_MONOTONIC]	 	= "monotonic",
1424 	[CLOCK_PROCESS_CPUTIME_ID]	= "process_cputime_id",
1425 	[CLOCK_THREAD_CPUTIME_ID]	= "thread_cputime_id",
1426 	[CLOCK_MONOTONIC_RAW]	 	= "monotonic_raw",
1427 	[CLOCK_REALTIME_COARSE]	 	= "realtime_coarse",
1428 	[CLOCK_MONOTONIC_COARSE] 	= "monotonic_coarse",
1429 	[CLOCK_BOOTTIME]	 	= "boottime",
1430 	[CLOCK_REALTIME_ALARM]		= "realtime_alarm",
1431 	[CLOCK_BOOTTIME_ALARM]		= "boottime_alarm",
1432 	[CLOCK_SGI_CYCLE]		= "sgi_cycle",
1433 	[CLOCK_TAI]		 	= "tai",
1434 };
1435 
1436 static ssize_t current_timestamp_clock_show(struct device *dev,
1437 					    struct device_attribute *attr,
1438 					    char *buf)
1439 {
1440 	const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1441 	const clockid_t clk = iio_device_get_clock(indio_dev);
1442 
1443 	switch (clk) {
1444 	case CLOCK_REALTIME:
1445 	case CLOCK_MONOTONIC:
1446 	case CLOCK_MONOTONIC_RAW:
1447 	case CLOCK_REALTIME_COARSE:
1448 	case CLOCK_MONOTONIC_COARSE:
1449 	case CLOCK_BOOTTIME:
1450 	case CLOCK_TAI:
1451 		break;
1452 	default:
1453 		BUG();
1454 	}
1455 
1456 	return sysfs_emit(buf, "%s\n", clock_names[clk]);
1457 }
1458 
1459 static ssize_t current_timestamp_clock_store(struct device *dev,
1460 					     struct device_attribute *attr,
1461 					     const char *buf, size_t len)
1462 {
1463 	clockid_t clk;
1464 	int ret;
1465 
1466 	ret = sysfs_match_string(clock_names, buf);
1467 	if (ret < 0)
1468 		return ret;
1469 	clk = ret;
1470 
1471 	switch (clk) {
1472 	case CLOCK_REALTIME:
1473 	case CLOCK_MONOTONIC:
1474 	case CLOCK_MONOTONIC_RAW:
1475 	case CLOCK_REALTIME_COARSE:
1476 	case CLOCK_MONOTONIC_COARSE:
1477 	case CLOCK_BOOTTIME:
1478 	case CLOCK_TAI:
1479 		break;
1480 	default:
1481 		return -EINVAL;
1482 	}
1483 
1484 	ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1485 	if (ret)
1486 		return ret;
1487 
1488 	return len;
1489 }
1490 
1491 int iio_device_register_sysfs_group(struct iio_dev *indio_dev,
1492 				    const struct attribute_group *group)
1493 {
1494 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1495 	const struct attribute_group **new, **old = iio_dev_opaque->groups;
1496 	unsigned int cnt = iio_dev_opaque->groupcounter;
1497 
1498 	new = krealloc_array(old, cnt + 2, sizeof(*new), GFP_KERNEL);
1499 	if (!new)
1500 		return -ENOMEM;
1501 
1502 	new[iio_dev_opaque->groupcounter++] = group;
1503 	new[iio_dev_opaque->groupcounter] = NULL;
1504 
1505 	iio_dev_opaque->groups = new;
1506 
1507 	return 0;
1508 }
1509 
1510 static DEVICE_ATTR_RW(current_timestamp_clock);
1511 
1512 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1513 {
1514 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1515 	int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1516 	struct iio_dev_attr *p;
1517 	struct attribute **attr, *clk = NULL;
1518 
1519 	/* First count elements in any existing group */
1520 	if (indio_dev->info->attrs) {
1521 		attr = indio_dev->info->attrs->attrs;
1522 		while (*attr++ != NULL)
1523 			attrcount_orig++;
1524 	}
1525 	attrcount = attrcount_orig;
1526 	/*
1527 	 * New channel registration method - relies on the fact a group does
1528 	 * not need to be initialized if its name is NULL.
1529 	 */
1530 	if (indio_dev->channels)
1531 		for (i = 0; i < indio_dev->num_channels; i++) {
1532 			const struct iio_chan_spec *chan =
1533 				&indio_dev->channels[i];
1534 
1535 			if (chan->type == IIO_TIMESTAMP)
1536 				clk = &dev_attr_current_timestamp_clock.attr;
1537 
1538 			ret = iio_device_add_channel_sysfs(indio_dev, chan);
1539 			if (ret < 0)
1540 				goto error_clear_attrs;
1541 			attrcount += ret;
1542 		}
1543 
1544 	if (iio_dev_opaque->event_interface)
1545 		clk = &dev_attr_current_timestamp_clock.attr;
1546 
1547 	if (indio_dev->name)
1548 		attrcount++;
1549 	if (indio_dev->label)
1550 		attrcount++;
1551 	if (clk)
1552 		attrcount++;
1553 
1554 	iio_dev_opaque->chan_attr_group.attrs =
1555 		kcalloc(attrcount + 1,
1556 			sizeof(iio_dev_opaque->chan_attr_group.attrs[0]),
1557 			GFP_KERNEL);
1558 	if (iio_dev_opaque->chan_attr_group.attrs == NULL) {
1559 		ret = -ENOMEM;
1560 		goto error_clear_attrs;
1561 	}
1562 	/* Copy across original attributes, and point to original binary attributes */
1563 	if (indio_dev->info->attrs) {
1564 		memcpy(iio_dev_opaque->chan_attr_group.attrs,
1565 		       indio_dev->info->attrs->attrs,
1566 		       sizeof(iio_dev_opaque->chan_attr_group.attrs[0])
1567 		       *attrcount_orig);
1568 		iio_dev_opaque->chan_attr_group.is_visible =
1569 			indio_dev->info->attrs->is_visible;
1570 		iio_dev_opaque->chan_attr_group.bin_attrs =
1571 			indio_dev->info->attrs->bin_attrs;
1572 	}
1573 	attrn = attrcount_orig;
1574 	/* Add all elements from the list. */
1575 	list_for_each_entry(p, &iio_dev_opaque->channel_attr_list, l)
1576 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1577 	if (indio_dev->name)
1578 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1579 	if (indio_dev->label)
1580 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &dev_attr_label.attr;
1581 	if (clk)
1582 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = clk;
1583 
1584 	ret = iio_device_register_sysfs_group(indio_dev,
1585 					      &iio_dev_opaque->chan_attr_group);
1586 	if (ret)
1587 		goto error_clear_attrs;
1588 
1589 	return 0;
1590 
1591 error_clear_attrs:
1592 	iio_free_chan_devattr_list(&iio_dev_opaque->channel_attr_list);
1593 
1594 	return ret;
1595 }
1596 
1597 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1598 {
1599 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1600 
1601 	iio_free_chan_devattr_list(&iio_dev_opaque->channel_attr_list);
1602 	kfree(iio_dev_opaque->chan_attr_group.attrs);
1603 	iio_dev_opaque->chan_attr_group.attrs = NULL;
1604 	kfree(iio_dev_opaque->groups);
1605 	iio_dev_opaque->groups = NULL;
1606 }
1607 
1608 static void iio_dev_release(struct device *device)
1609 {
1610 	struct iio_dev *indio_dev = dev_to_iio_dev(device);
1611 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1612 
1613 	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1614 		iio_device_unregister_trigger_consumer(indio_dev);
1615 	iio_device_unregister_eventset(indio_dev);
1616 	iio_device_unregister_sysfs(indio_dev);
1617 
1618 	iio_device_detach_buffers(indio_dev);
1619 
1620 	lockdep_unregister_key(&iio_dev_opaque->mlock_key);
1621 
1622 	ida_free(&iio_ida, iio_dev_opaque->id);
1623 	kfree(iio_dev_opaque);
1624 }
1625 
1626 const struct device_type iio_device_type = {
1627 	.name = "iio_device",
1628 	.release = iio_dev_release,
1629 };
1630 
1631 /**
1632  * iio_device_alloc() - allocate an iio_dev from a driver
1633  * @parent:		Parent device.
1634  * @sizeof_priv:	Space to allocate for private structure.
1635  *
1636  * Returns:
1637  * Pointer to allocated iio_dev on success, NULL on failure.
1638  */
1639 struct iio_dev *iio_device_alloc(struct device *parent, int sizeof_priv)
1640 {
1641 	struct iio_dev_opaque *iio_dev_opaque;
1642 	struct iio_dev *indio_dev;
1643 	size_t alloc_size;
1644 
1645 	alloc_size = sizeof(struct iio_dev_opaque);
1646 	if (sizeof_priv) {
1647 		alloc_size = ALIGN(alloc_size, IIO_DMA_MINALIGN);
1648 		alloc_size += sizeof_priv;
1649 	}
1650 
1651 	iio_dev_opaque = kzalloc(alloc_size, GFP_KERNEL);
1652 	if (!iio_dev_opaque)
1653 		return NULL;
1654 
1655 	indio_dev = &iio_dev_opaque->indio_dev;
1656 	indio_dev->priv = (char *)iio_dev_opaque +
1657 		ALIGN(sizeof(struct iio_dev_opaque), IIO_DMA_MINALIGN);
1658 
1659 	indio_dev->dev.parent = parent;
1660 	indio_dev->dev.type = &iio_device_type;
1661 	indio_dev->dev.bus = &iio_bus_type;
1662 	device_initialize(&indio_dev->dev);
1663 	mutex_init(&iio_dev_opaque->mlock);
1664 	mutex_init(&iio_dev_opaque->info_exist_lock);
1665 	INIT_LIST_HEAD(&iio_dev_opaque->channel_attr_list);
1666 
1667 	iio_dev_opaque->id = ida_alloc(&iio_ida, GFP_KERNEL);
1668 	if (iio_dev_opaque->id < 0) {
1669 		/* cannot use a dev_err as the name isn't available */
1670 		pr_err("failed to get device id\n");
1671 		kfree(iio_dev_opaque);
1672 		return NULL;
1673 	}
1674 
1675 	if (dev_set_name(&indio_dev->dev, "iio:device%d", iio_dev_opaque->id)) {
1676 		ida_free(&iio_ida, iio_dev_opaque->id);
1677 		kfree(iio_dev_opaque);
1678 		return NULL;
1679 	}
1680 
1681 	INIT_LIST_HEAD(&iio_dev_opaque->buffer_list);
1682 	INIT_LIST_HEAD(&iio_dev_opaque->ioctl_handlers);
1683 
1684 	lockdep_register_key(&iio_dev_opaque->mlock_key);
1685 	lockdep_set_class(&iio_dev_opaque->mlock, &iio_dev_opaque->mlock_key);
1686 
1687 	return indio_dev;
1688 }
1689 EXPORT_SYMBOL(iio_device_alloc);
1690 
1691 /**
1692  * iio_device_free() - free an iio_dev from a driver
1693  * @dev:		the iio_dev associated with the device
1694  */
1695 void iio_device_free(struct iio_dev *dev)
1696 {
1697 	if (dev)
1698 		put_device(&dev->dev);
1699 }
1700 EXPORT_SYMBOL(iio_device_free);
1701 
1702 static void devm_iio_device_release(void *iio_dev)
1703 {
1704 	iio_device_free(iio_dev);
1705 }
1706 
1707 /**
1708  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1709  * @parent:		Device to allocate iio_dev for, and parent for this IIO device
1710  * @sizeof_priv:	Space to allocate for private structure.
1711  *
1712  * Managed iio_device_alloc. iio_dev allocated with this function is
1713  * automatically freed on driver detach.
1714  *
1715  * Returns:
1716  * Pointer to allocated iio_dev on success, NULL on failure.
1717  */
1718 struct iio_dev *devm_iio_device_alloc(struct device *parent, int sizeof_priv)
1719 {
1720 	struct iio_dev *iio_dev;
1721 	int ret;
1722 
1723 	iio_dev = iio_device_alloc(parent, sizeof_priv);
1724 	if (!iio_dev)
1725 		return NULL;
1726 
1727 	ret = devm_add_action_or_reset(parent, devm_iio_device_release,
1728 				       iio_dev);
1729 	if (ret)
1730 		return NULL;
1731 
1732 	return iio_dev;
1733 }
1734 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1735 
1736 /**
1737  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1738  * @inode:	Inode structure for identifying the device in the file system
1739  * @filp:	File structure for iio device used to keep and later access
1740  *		private data
1741  *
1742  * Returns: 0 on success or -EBUSY if the device is already opened
1743  */
1744 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1745 {
1746 	struct iio_dev_opaque *iio_dev_opaque =
1747 		container_of(inode->i_cdev, struct iio_dev_opaque, chrdev);
1748 	struct iio_dev *indio_dev = &iio_dev_opaque->indio_dev;
1749 	struct iio_dev_buffer_pair *ib;
1750 
1751 	if (test_and_set_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags))
1752 		return -EBUSY;
1753 
1754 	iio_device_get(indio_dev);
1755 
1756 	ib = kmalloc(sizeof(*ib), GFP_KERNEL);
1757 	if (!ib) {
1758 		iio_device_put(indio_dev);
1759 		clear_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags);
1760 		return -ENOMEM;
1761 	}
1762 
1763 	ib->indio_dev = indio_dev;
1764 	ib->buffer = indio_dev->buffer;
1765 
1766 	filp->private_data = ib;
1767 
1768 	return 0;
1769 }
1770 
1771 /**
1772  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1773  * @inode:	Inode structure pointer for the char device
1774  * @filp:	File structure pointer for the char device
1775  *
1776  * Returns: 0 for successful release.
1777  */
1778 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1779 {
1780 	struct iio_dev_buffer_pair *ib = filp->private_data;
1781 	struct iio_dev_opaque *iio_dev_opaque =
1782 		container_of(inode->i_cdev, struct iio_dev_opaque, chrdev);
1783 	struct iio_dev *indio_dev = &iio_dev_opaque->indio_dev;
1784 
1785 	kfree(ib);
1786 	clear_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags);
1787 	iio_device_put(indio_dev);
1788 
1789 	return 0;
1790 }
1791 
1792 void iio_device_ioctl_handler_register(struct iio_dev *indio_dev,
1793 				       struct iio_ioctl_handler *h)
1794 {
1795 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1796 
1797 	list_add_tail(&h->entry, &iio_dev_opaque->ioctl_handlers);
1798 }
1799 
1800 void iio_device_ioctl_handler_unregister(struct iio_ioctl_handler *h)
1801 {
1802 	list_del(&h->entry);
1803 }
1804 
1805 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1806 {
1807 	struct iio_dev_buffer_pair *ib = filp->private_data;
1808 	struct iio_dev *indio_dev = ib->indio_dev;
1809 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1810 	struct iio_ioctl_handler *h;
1811 	int ret = -ENODEV;
1812 
1813 	mutex_lock(&iio_dev_opaque->info_exist_lock);
1814 
1815 	/*
1816 	 * The NULL check here is required to prevent crashing when a device
1817 	 * is being removed while userspace would still have open file handles
1818 	 * to try to access this device.
1819 	 */
1820 	if (!indio_dev->info)
1821 		goto out_unlock;
1822 
1823 	list_for_each_entry(h, &iio_dev_opaque->ioctl_handlers, entry) {
1824 		ret = h->ioctl(indio_dev, filp, cmd, arg);
1825 		if (ret != IIO_IOCTL_UNHANDLED)
1826 			break;
1827 	}
1828 
1829 	if (ret == IIO_IOCTL_UNHANDLED)
1830 		ret = -ENODEV;
1831 
1832 out_unlock:
1833 	mutex_unlock(&iio_dev_opaque->info_exist_lock);
1834 
1835 	return ret;
1836 }
1837 
1838 static const struct file_operations iio_buffer_fileops = {
1839 	.owner = THIS_MODULE,
1840 	.llseek = noop_llseek,
1841 	.read = iio_buffer_read_outer_addr,
1842 	.write = iio_buffer_write_outer_addr,
1843 	.poll = iio_buffer_poll_addr,
1844 	.unlocked_ioctl = iio_ioctl,
1845 	.compat_ioctl = compat_ptr_ioctl,
1846 	.open = iio_chrdev_open,
1847 	.release = iio_chrdev_release,
1848 };
1849 
1850 static const struct file_operations iio_event_fileops = {
1851 	.owner = THIS_MODULE,
1852 	.llseek = noop_llseek,
1853 	.unlocked_ioctl = iio_ioctl,
1854 	.compat_ioctl = compat_ptr_ioctl,
1855 	.open = iio_chrdev_open,
1856 	.release = iio_chrdev_release,
1857 };
1858 
1859 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1860 {
1861 	int i, j;
1862 	const struct iio_chan_spec *channels = indio_dev->channels;
1863 
1864 	if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1865 		return 0;
1866 
1867 	for (i = 0; i < indio_dev->num_channels - 1; i++) {
1868 		if (channels[i].scan_index < 0)
1869 			continue;
1870 		for (j = i + 1; j < indio_dev->num_channels; j++)
1871 			if (channels[i].scan_index == channels[j].scan_index) {
1872 				dev_err(&indio_dev->dev,
1873 					"Duplicate scan index %d\n",
1874 					channels[i].scan_index);
1875 				return -EINVAL;
1876 			}
1877 	}
1878 
1879 	return 0;
1880 }
1881 
1882 static int iio_check_extended_name(const struct iio_dev *indio_dev)
1883 {
1884 	unsigned int i;
1885 
1886 	if (!indio_dev->info->read_label)
1887 		return 0;
1888 
1889 	for (i = 0; i < indio_dev->num_channels; i++) {
1890 		if (indio_dev->channels[i].extend_name) {
1891 			dev_err(&indio_dev->dev,
1892 				"Cannot use labels and extend_name at the same time\n");
1893 			return -EINVAL;
1894 		}
1895 	}
1896 
1897 	return 0;
1898 }
1899 
1900 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1901 
1902 static void iio_sanity_check_avail_scan_masks(struct iio_dev *indio_dev)
1903 {
1904 	unsigned int num_masks, masklength, longs_per_mask;
1905 	const unsigned long *av_masks;
1906 	int i;
1907 
1908 	av_masks = indio_dev->available_scan_masks;
1909 	masklength = indio_dev->masklength;
1910 	longs_per_mask = BITS_TO_LONGS(masklength);
1911 
1912 	/*
1913 	 * The code determining how many available_scan_masks is in the array
1914 	 * will be assuming the end of masks when first long with all bits
1915 	 * zeroed is encountered. This is incorrect for masks where mask
1916 	 * consists of more than one long, and where some of the available masks
1917 	 * has long worth of bits zeroed (but has subsequent bit(s) set). This
1918 	 * is a safety measure against bug where array of masks is terminated by
1919 	 * a single zero while mask width is greater than width of a long.
1920 	 */
1921 	if (longs_per_mask > 1)
1922 		dev_warn(indio_dev->dev.parent,
1923 			 "multi long available scan masks not fully supported\n");
1924 
1925 	if (bitmap_empty(av_masks, masklength))
1926 		dev_warn(indio_dev->dev.parent, "empty scan mask\n");
1927 
1928 	for (num_masks = 0; *av_masks; num_masks++)
1929 		av_masks += longs_per_mask;
1930 
1931 	if (num_masks < 2)
1932 		return;
1933 
1934 	av_masks = indio_dev->available_scan_masks;
1935 
1936 	/*
1937 	 * Go through all the masks from first to one before the last, and see
1938 	 * that no mask found later from the available_scan_masks array is a
1939 	 * subset of mask found earlier. If this happens, then the mask found
1940 	 * later will never get used because scanning the array is stopped when
1941 	 * the first suitable mask is found. Drivers should order the array of
1942 	 * available masks in the order of preference (presumably the least
1943 	 * costy to access masks first).
1944 	 */
1945 	for (i = 0; i < num_masks - 1; i++) {
1946 		const unsigned long *mask1;
1947 		int j;
1948 
1949 		mask1 = av_masks + i * longs_per_mask;
1950 		for (j = i + 1; j < num_masks; j++) {
1951 			const unsigned long *mask2;
1952 
1953 			mask2 = av_masks + j * longs_per_mask;
1954 			if (bitmap_subset(mask2, mask1, masklength))
1955 				dev_warn(indio_dev->dev.parent,
1956 					 "available_scan_mask %d subset of %d. Never used\n",
1957 					 j, i);
1958 		}
1959 	}
1960 }
1961 
1962 int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1963 {
1964 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1965 	struct fwnode_handle *fwnode = NULL;
1966 	int ret;
1967 
1968 	if (!indio_dev->info)
1969 		return -EINVAL;
1970 
1971 	iio_dev_opaque->driver_module = this_mod;
1972 
1973 	/* If the calling driver did not initialize firmware node, do it here */
1974 	if (dev_fwnode(&indio_dev->dev))
1975 		fwnode = dev_fwnode(&indio_dev->dev);
1976 	/* The default dummy IIO device has no parent */
1977 	else if (indio_dev->dev.parent)
1978 		fwnode = dev_fwnode(indio_dev->dev.parent);
1979 	device_set_node(&indio_dev->dev, fwnode);
1980 
1981 	fwnode_property_read_string(fwnode, "label", &indio_dev->label);
1982 
1983 	ret = iio_check_unique_scan_index(indio_dev);
1984 	if (ret < 0)
1985 		return ret;
1986 
1987 	ret = iio_check_extended_name(indio_dev);
1988 	if (ret < 0)
1989 		return ret;
1990 
1991 	iio_device_register_debugfs(indio_dev);
1992 
1993 	ret = iio_buffers_alloc_sysfs_and_mask(indio_dev);
1994 	if (ret) {
1995 		dev_err(indio_dev->dev.parent,
1996 			"Failed to create buffer sysfs interfaces\n");
1997 		goto error_unreg_debugfs;
1998 	}
1999 
2000 	if (indio_dev->available_scan_masks)
2001 		iio_sanity_check_avail_scan_masks(indio_dev);
2002 
2003 	ret = iio_device_register_sysfs(indio_dev);
2004 	if (ret) {
2005 		dev_err(indio_dev->dev.parent,
2006 			"Failed to register sysfs interfaces\n");
2007 		goto error_buffer_free_sysfs;
2008 	}
2009 	ret = iio_device_register_eventset(indio_dev);
2010 	if (ret) {
2011 		dev_err(indio_dev->dev.parent,
2012 			"Failed to register event set\n");
2013 		goto error_free_sysfs;
2014 	}
2015 	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
2016 		iio_device_register_trigger_consumer(indio_dev);
2017 
2018 	if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
2019 		indio_dev->setup_ops == NULL)
2020 		indio_dev->setup_ops = &noop_ring_setup_ops;
2021 
2022 	if (iio_dev_opaque->attached_buffers_cnt)
2023 		cdev_init(&iio_dev_opaque->chrdev, &iio_buffer_fileops);
2024 	else if (iio_dev_opaque->event_interface)
2025 		cdev_init(&iio_dev_opaque->chrdev, &iio_event_fileops);
2026 
2027 	if (iio_dev_opaque->attached_buffers_cnt || iio_dev_opaque->event_interface) {
2028 		indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), iio_dev_opaque->id);
2029 		iio_dev_opaque->chrdev.owner = this_mod;
2030 	}
2031 
2032 	/* assign device groups now; they should be all registered now */
2033 	indio_dev->dev.groups = iio_dev_opaque->groups;
2034 
2035 	ret = cdev_device_add(&iio_dev_opaque->chrdev, &indio_dev->dev);
2036 	if (ret < 0)
2037 		goto error_unreg_eventset;
2038 
2039 	return 0;
2040 
2041 error_unreg_eventset:
2042 	iio_device_unregister_eventset(indio_dev);
2043 error_free_sysfs:
2044 	iio_device_unregister_sysfs(indio_dev);
2045 error_buffer_free_sysfs:
2046 	iio_buffers_free_sysfs_and_mask(indio_dev);
2047 error_unreg_debugfs:
2048 	iio_device_unregister_debugfs(indio_dev);
2049 	return ret;
2050 }
2051 EXPORT_SYMBOL(__iio_device_register);
2052 
2053 /**
2054  * iio_device_unregister() - unregister a device from the IIO subsystem
2055  * @indio_dev:		Device structure representing the device.
2056  */
2057 void iio_device_unregister(struct iio_dev *indio_dev)
2058 {
2059 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2060 
2061 	cdev_device_del(&iio_dev_opaque->chrdev, &indio_dev->dev);
2062 
2063 	mutex_lock(&iio_dev_opaque->info_exist_lock);
2064 
2065 	iio_device_unregister_debugfs(indio_dev);
2066 
2067 	iio_disable_all_buffers(indio_dev);
2068 
2069 	indio_dev->info = NULL;
2070 
2071 	iio_device_wakeup_eventset(indio_dev);
2072 	iio_buffer_wakeup_poll(indio_dev);
2073 
2074 	mutex_unlock(&iio_dev_opaque->info_exist_lock);
2075 
2076 	iio_buffers_free_sysfs_and_mask(indio_dev);
2077 }
2078 EXPORT_SYMBOL(iio_device_unregister);
2079 
2080 static void devm_iio_device_unreg(void *indio_dev)
2081 {
2082 	iio_device_unregister(indio_dev);
2083 }
2084 
2085 int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
2086 			       struct module *this_mod)
2087 {
2088 	int ret;
2089 
2090 	ret = __iio_device_register(indio_dev, this_mod);
2091 	if (ret)
2092 		return ret;
2093 
2094 	return devm_add_action_or_reset(dev, devm_iio_device_unreg, indio_dev);
2095 }
2096 EXPORT_SYMBOL_GPL(__devm_iio_device_register);
2097 
2098 /**
2099  * iio_device_claim_direct_mode - Keep device in direct mode
2100  * @indio_dev:	the iio_dev associated with the device
2101  *
2102  * If the device is in direct mode it is guaranteed to stay
2103  * that way until iio_device_release_direct_mode() is called.
2104  *
2105  * Use with iio_device_release_direct_mode()
2106  *
2107  * Returns: 0 on success, -EBUSY on failure.
2108  */
2109 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
2110 {
2111 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2112 
2113 	mutex_lock(&iio_dev_opaque->mlock);
2114 
2115 	if (iio_buffer_enabled(indio_dev)) {
2116 		mutex_unlock(&iio_dev_opaque->mlock);
2117 		return -EBUSY;
2118 	}
2119 	return 0;
2120 }
2121 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
2122 
2123 /**
2124  * iio_device_release_direct_mode - releases claim on direct mode
2125  * @indio_dev:	the iio_dev associated with the device
2126  *
2127  * Release the claim. Device is no longer guaranteed to stay
2128  * in direct mode.
2129  *
2130  * Use with iio_device_claim_direct_mode()
2131  */
2132 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
2133 {
2134 	mutex_unlock(&to_iio_dev_opaque(indio_dev)->mlock);
2135 }
2136 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
2137 
2138 /**
2139  * iio_device_claim_buffer_mode - Keep device in buffer mode
2140  * @indio_dev:	the iio_dev associated with the device
2141  *
2142  * If the device is in buffer mode it is guaranteed to stay
2143  * that way until iio_device_release_buffer_mode() is called.
2144  *
2145  * Use with iio_device_release_buffer_mode().
2146  *
2147  * Returns: 0 on success, -EBUSY on failure.
2148  */
2149 int iio_device_claim_buffer_mode(struct iio_dev *indio_dev)
2150 {
2151 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2152 
2153 	mutex_lock(&iio_dev_opaque->mlock);
2154 
2155 	if (iio_buffer_enabled(indio_dev))
2156 		return 0;
2157 
2158 	mutex_unlock(&iio_dev_opaque->mlock);
2159 	return -EBUSY;
2160 }
2161 EXPORT_SYMBOL_GPL(iio_device_claim_buffer_mode);
2162 
2163 /**
2164  * iio_device_release_buffer_mode - releases claim on buffer mode
2165  * @indio_dev:	the iio_dev associated with the device
2166  *
2167  * Release the claim. Device is no longer guaranteed to stay
2168  * in buffer mode.
2169  *
2170  * Use with iio_device_claim_buffer_mode().
2171  */
2172 void iio_device_release_buffer_mode(struct iio_dev *indio_dev)
2173 {
2174 	mutex_unlock(&to_iio_dev_opaque(indio_dev)->mlock);
2175 }
2176 EXPORT_SYMBOL_GPL(iio_device_release_buffer_mode);
2177 
2178 /**
2179  * iio_device_get_current_mode() - helper function providing read-only access to
2180  *				   the opaque @currentmode variable
2181  * @indio_dev:			   IIO device structure for device
2182  */
2183 int iio_device_get_current_mode(struct iio_dev *indio_dev)
2184 {
2185 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2186 
2187 	return iio_dev_opaque->currentmode;
2188 }
2189 EXPORT_SYMBOL_GPL(iio_device_get_current_mode);
2190 
2191 subsys_initcall(iio_init);
2192 module_exit(iio_exit);
2193 
2194 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
2195 MODULE_DESCRIPTION("Industrial I/O core");
2196 MODULE_LICENSE("GPL");
2197