xref: /linux/drivers/iio/industrialio-core.c (revision 4b660dbd9ee2059850fd30e0df420ca7a38a1856)
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 const 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 & INDIO_ALL_BUFFER_MODES;
217 }
218 EXPORT_SYMBOL_GPL(iio_buffer_enabled);
219 
220 #if defined(CONFIG_DEBUG_FS)
221 /*
222  * There's also a CONFIG_DEBUG_FS guard in include/linux/iio/iio.h for
223  * iio_get_debugfs_dentry() to make it inline if CONFIG_DEBUG_FS is undefined
224  */
225 struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
226 {
227 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
228 
229 	return iio_dev_opaque->debugfs_dentry;
230 }
231 EXPORT_SYMBOL_GPL(iio_get_debugfs_dentry);
232 #endif
233 
234 /**
235  * iio_find_channel_from_si() - get channel from its scan index
236  * @indio_dev:		device
237  * @si:			scan index to match
238  *
239  * Returns:
240  * Constant pointer to iio_chan_spec, if scan index matches, NULL on failure.
241  */
242 const struct iio_chan_spec
243 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
244 {
245 	int i;
246 
247 	for (i = 0; i < indio_dev->num_channels; i++)
248 		if (indio_dev->channels[i].scan_index == si)
249 			return &indio_dev->channels[i];
250 	return NULL;
251 }
252 
253 /* This turns up an awful lot */
254 ssize_t iio_read_const_attr(struct device *dev,
255 			    struct device_attribute *attr,
256 			    char *buf)
257 {
258 	return sysfs_emit(buf, "%s\n", to_iio_const_attr(attr)->string);
259 }
260 EXPORT_SYMBOL(iio_read_const_attr);
261 
262 /**
263  * iio_device_set_clock() - Set current timestamping clock for the device
264  * @indio_dev: IIO device structure containing the device
265  * @clock_id: timestamping clock POSIX identifier to set.
266  *
267  * Returns: 0 on success, or a negative error code.
268  */
269 int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
270 {
271 	int ret;
272 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
273 	const struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
274 
275 	ret = mutex_lock_interruptible(&iio_dev_opaque->mlock);
276 	if (ret)
277 		return ret;
278 	if ((ev_int && iio_event_enabled(ev_int)) ||
279 	    iio_buffer_enabled(indio_dev)) {
280 		mutex_unlock(&iio_dev_opaque->mlock);
281 		return -EBUSY;
282 	}
283 	iio_dev_opaque->clock_id = clock_id;
284 	mutex_unlock(&iio_dev_opaque->mlock);
285 
286 	return 0;
287 }
288 EXPORT_SYMBOL(iio_device_set_clock);
289 
290 /**
291  * iio_device_get_clock() - Retrieve current timestamping clock for the device
292  * @indio_dev: IIO device structure containing the device
293  *
294  * Returns: Clock ID of the current timestamping clock for the device.
295  */
296 clockid_t iio_device_get_clock(const struct iio_dev *indio_dev)
297 {
298 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
299 
300 	return iio_dev_opaque->clock_id;
301 }
302 EXPORT_SYMBOL(iio_device_get_clock);
303 
304 /**
305  * iio_get_time_ns() - utility function to get a time stamp for events etc
306  * @indio_dev: device
307  *
308  * Returns: Timestamp of the event in nanoseconds.
309  */
310 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
311 {
312 	struct timespec64 tp;
313 
314 	switch (iio_device_get_clock(indio_dev)) {
315 	case CLOCK_REALTIME:
316 		return ktime_get_real_ns();
317 	case CLOCK_MONOTONIC:
318 		return ktime_get_ns();
319 	case CLOCK_MONOTONIC_RAW:
320 		return ktime_get_raw_ns();
321 	case CLOCK_REALTIME_COARSE:
322 		return ktime_to_ns(ktime_get_coarse_real());
323 	case CLOCK_MONOTONIC_COARSE:
324 		ktime_get_coarse_ts64(&tp);
325 		return timespec64_to_ns(&tp);
326 	case CLOCK_BOOTTIME:
327 		return ktime_get_boottime_ns();
328 	case CLOCK_TAI:
329 		return ktime_get_clocktai_ns();
330 	default:
331 		BUG();
332 	}
333 }
334 EXPORT_SYMBOL(iio_get_time_ns);
335 
336 static int __init iio_init(void)
337 {
338 	int ret;
339 
340 	/* Register sysfs bus */
341 	ret  = bus_register(&iio_bus_type);
342 	if (ret < 0) {
343 		pr_err("could not register bus type\n");
344 		goto error_nothing;
345 	}
346 
347 	ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
348 	if (ret < 0) {
349 		pr_err("failed to allocate char dev region\n");
350 		goto error_unregister_bus_type;
351 	}
352 
353 	iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
354 
355 	return 0;
356 
357 error_unregister_bus_type:
358 	bus_unregister(&iio_bus_type);
359 error_nothing:
360 	return ret;
361 }
362 
363 static void __exit iio_exit(void)
364 {
365 	if (iio_devt)
366 		unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
367 	bus_unregister(&iio_bus_type);
368 	debugfs_remove(iio_debugfs_dentry);
369 }
370 
371 #if defined(CONFIG_DEBUG_FS)
372 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
373 			      size_t count, loff_t *ppos)
374 {
375 	struct iio_dev *indio_dev = file->private_data;
376 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
377 	unsigned int val = 0;
378 	int ret;
379 
380 	if (*ppos > 0)
381 		return simple_read_from_buffer(userbuf, count, ppos,
382 					       iio_dev_opaque->read_buf,
383 					       iio_dev_opaque->read_buf_len);
384 
385 	ret = indio_dev->info->debugfs_reg_access(indio_dev,
386 						  iio_dev_opaque->cached_reg_addr,
387 						  0, &val);
388 	if (ret) {
389 		dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
390 		return ret;
391 	}
392 
393 	iio_dev_opaque->read_buf_len = snprintf(iio_dev_opaque->read_buf,
394 						sizeof(iio_dev_opaque->read_buf),
395 						"0x%X\n", val);
396 
397 	return simple_read_from_buffer(userbuf, count, ppos,
398 				       iio_dev_opaque->read_buf,
399 				       iio_dev_opaque->read_buf_len);
400 }
401 
402 static ssize_t iio_debugfs_write_reg(struct file *file,
403 		     const char __user *userbuf, size_t count, loff_t *ppos)
404 {
405 	struct iio_dev *indio_dev = file->private_data;
406 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
407 	unsigned int reg, val;
408 	char buf[80];
409 	int ret;
410 
411 	count = min(count, sizeof(buf) - 1);
412 	if (copy_from_user(buf, userbuf, count))
413 		return -EFAULT;
414 
415 	buf[count] = 0;
416 
417 	ret = sscanf(buf, "%i %i", &reg, &val);
418 
419 	switch (ret) {
420 	case 1:
421 		iio_dev_opaque->cached_reg_addr = reg;
422 		break;
423 	case 2:
424 		iio_dev_opaque->cached_reg_addr = reg;
425 		ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
426 							  val, NULL);
427 		if (ret) {
428 			dev_err(indio_dev->dev.parent, "%s: write failed\n",
429 				__func__);
430 			return ret;
431 		}
432 		break;
433 	default:
434 		return -EINVAL;
435 	}
436 
437 	return count;
438 }
439 
440 static const struct file_operations iio_debugfs_reg_fops = {
441 	.open = simple_open,
442 	.read = iio_debugfs_read_reg,
443 	.write = iio_debugfs_write_reg,
444 };
445 
446 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
447 {
448 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
449 
450 	debugfs_remove_recursive(iio_dev_opaque->debugfs_dentry);
451 }
452 
453 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
454 {
455 	struct iio_dev_opaque *iio_dev_opaque;
456 
457 	if (indio_dev->info->debugfs_reg_access == NULL)
458 		return;
459 
460 	if (!iio_debugfs_dentry)
461 		return;
462 
463 	iio_dev_opaque = to_iio_dev_opaque(indio_dev);
464 
465 	iio_dev_opaque->debugfs_dentry =
466 		debugfs_create_dir(dev_name(&indio_dev->dev),
467 				   iio_debugfs_dentry);
468 
469 	debugfs_create_file("direct_reg_access", 0644,
470 			    iio_dev_opaque->debugfs_dentry, indio_dev,
471 			    &iio_debugfs_reg_fops);
472 }
473 #else
474 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
475 {
476 }
477 
478 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
479 {
480 }
481 #endif /* CONFIG_DEBUG_FS */
482 
483 static ssize_t iio_read_channel_ext_info(struct device *dev,
484 				     struct device_attribute *attr,
485 				     char *buf)
486 {
487 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
488 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
489 	const struct iio_chan_spec_ext_info *ext_info;
490 
491 	ext_info = &this_attr->c->ext_info[this_attr->address];
492 
493 	return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
494 }
495 
496 static ssize_t iio_write_channel_ext_info(struct device *dev,
497 				     struct device_attribute *attr,
498 				     const char *buf, size_t len)
499 {
500 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
501 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
502 	const struct iio_chan_spec_ext_info *ext_info;
503 
504 	ext_info = &this_attr->c->ext_info[this_attr->address];
505 
506 	return ext_info->write(indio_dev, ext_info->private,
507 			       this_attr->c, buf, len);
508 }
509 
510 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
511 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
512 {
513 	const struct iio_enum *e = (const struct iio_enum *)priv;
514 	unsigned int i;
515 	size_t len = 0;
516 
517 	if (!e->num_items)
518 		return 0;
519 
520 	for (i = 0; i < e->num_items; ++i) {
521 		if (!e->items[i])
522 			continue;
523 		len += sysfs_emit_at(buf, len, "%s ", e->items[i]);
524 	}
525 
526 	/* replace last space with a newline */
527 	buf[len - 1] = '\n';
528 
529 	return len;
530 }
531 EXPORT_SYMBOL_GPL(iio_enum_available_read);
532 
533 ssize_t iio_enum_read(struct iio_dev *indio_dev,
534 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
535 {
536 	const struct iio_enum *e = (const struct iio_enum *)priv;
537 	int i;
538 
539 	if (!e->get)
540 		return -EINVAL;
541 
542 	i = e->get(indio_dev, chan);
543 	if (i < 0)
544 		return i;
545 	if (i >= e->num_items || !e->items[i])
546 		return -EINVAL;
547 
548 	return sysfs_emit(buf, "%s\n", e->items[i]);
549 }
550 EXPORT_SYMBOL_GPL(iio_enum_read);
551 
552 ssize_t iio_enum_write(struct iio_dev *indio_dev,
553 	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
554 	size_t len)
555 {
556 	const struct iio_enum *e = (const struct iio_enum *)priv;
557 	int ret;
558 
559 	if (!e->set)
560 		return -EINVAL;
561 
562 	ret = __sysfs_match_string(e->items, e->num_items, buf);
563 	if (ret < 0)
564 		return ret;
565 
566 	ret = e->set(indio_dev, chan, ret);
567 	return ret ? ret : len;
568 }
569 EXPORT_SYMBOL_GPL(iio_enum_write);
570 
571 static const struct iio_mount_matrix iio_mount_idmatrix = {
572 	.rotation = {
573 		"1", "0", "0",
574 		"0", "1", "0",
575 		"0", "0", "1"
576 	}
577 };
578 
579 static int iio_setup_mount_idmatrix(const struct device *dev,
580 				    struct iio_mount_matrix *matrix)
581 {
582 	*matrix = iio_mount_idmatrix;
583 	dev_info(dev, "mounting matrix not found: using identity...\n");
584 	return 0;
585 }
586 
587 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
588 			      const struct iio_chan_spec *chan, char *buf)
589 {
590 	const struct iio_mount_matrix *mtx;
591 
592 	mtx = ((iio_get_mount_matrix_t *)priv)(indio_dev, chan);
593 	if (IS_ERR(mtx))
594 		return PTR_ERR(mtx);
595 
596 	if (!mtx)
597 		mtx = &iio_mount_idmatrix;
598 
599 	return sysfs_emit(buf, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
600 			  mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
601 			  mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
602 			  mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
603 }
604 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
605 
606 /**
607  * iio_read_mount_matrix() - retrieve iio device mounting matrix from
608  *                           device "mount-matrix" property
609  * @dev:	device the mounting matrix property is assigned to
610  * @matrix:	where to store retrieved matrix
611  *
612  * If device is assigned no mounting matrix property, a default 3x3 identity
613  * matrix will be filled in.
614  *
615  * Returns: 0 if success, or a negative error code on failure.
616  */
617 int iio_read_mount_matrix(struct device *dev, struct iio_mount_matrix *matrix)
618 {
619 	size_t len = ARRAY_SIZE(iio_mount_idmatrix.rotation);
620 	int err;
621 
622 	err = device_property_read_string_array(dev, "mount-matrix", matrix->rotation, len);
623 	if (err == len)
624 		return 0;
625 
626 	if (err >= 0)
627 		/* Invalid number of matrix entries. */
628 		return -EINVAL;
629 
630 	if (err != -EINVAL)
631 		/* Invalid matrix declaration format. */
632 		return err;
633 
634 	/* Matrix was not declared at all: fallback to identity. */
635 	return iio_setup_mount_idmatrix(dev, matrix);
636 }
637 EXPORT_SYMBOL(iio_read_mount_matrix);
638 
639 static ssize_t __iio_format_value(char *buf, size_t offset, unsigned int type,
640 				  int size, const int *vals)
641 {
642 	int tmp0, tmp1;
643 	s64 tmp2;
644 	bool scale_db = false;
645 
646 	switch (type) {
647 	case IIO_VAL_INT:
648 		return sysfs_emit_at(buf, offset, "%d", vals[0]);
649 	case IIO_VAL_INT_PLUS_MICRO_DB:
650 		scale_db = true;
651 		fallthrough;
652 	case IIO_VAL_INT_PLUS_MICRO:
653 		if (vals[1] < 0)
654 			return sysfs_emit_at(buf, offset, "-%d.%06u%s",
655 					     abs(vals[0]), -vals[1],
656 					     scale_db ? " dB" : "");
657 		else
658 			return sysfs_emit_at(buf, offset, "%d.%06u%s", vals[0],
659 					     vals[1], scale_db ? " dB" : "");
660 	case IIO_VAL_INT_PLUS_NANO:
661 		if (vals[1] < 0)
662 			return sysfs_emit_at(buf, offset, "-%d.%09u",
663 					     abs(vals[0]), -vals[1]);
664 		else
665 			return sysfs_emit_at(buf, offset, "%d.%09u", vals[0],
666 					     vals[1]);
667 	case IIO_VAL_FRACTIONAL:
668 		tmp2 = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
669 		tmp1 = vals[1];
670 		tmp0 = (int)div_s64_rem(tmp2, 1000000000, &tmp1);
671 		if ((tmp2 < 0) && (tmp0 == 0))
672 			return sysfs_emit_at(buf, offset, "-0.%09u", abs(tmp1));
673 		else
674 			return sysfs_emit_at(buf, offset, "%d.%09u", tmp0,
675 					     abs(tmp1));
676 	case IIO_VAL_FRACTIONAL_LOG2:
677 		tmp2 = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
678 		tmp0 = (int)div_s64_rem(tmp2, 1000000000LL, &tmp1);
679 		if (tmp0 == 0 && tmp2 < 0)
680 			return sysfs_emit_at(buf, offset, "-0.%09u", abs(tmp1));
681 		else
682 			return sysfs_emit_at(buf, offset, "%d.%09u", tmp0,
683 					     abs(tmp1));
684 	case IIO_VAL_INT_MULTIPLE:
685 	{
686 		int i;
687 		int l = 0;
688 
689 		for (i = 0; i < size; ++i)
690 			l += sysfs_emit_at(buf, offset + l, "%d ", vals[i]);
691 		return l;
692 	}
693 	case IIO_VAL_CHAR:
694 		return sysfs_emit_at(buf, offset, "%c", (char)vals[0]);
695 	case IIO_VAL_INT_64:
696 		tmp2 = (s64)((((u64)vals[1]) << 32) | (u32)vals[0]);
697 		return sysfs_emit_at(buf, offset, "%lld", tmp2);
698 	default:
699 		return 0;
700 	}
701 }
702 
703 /**
704  * iio_format_value() - Formats a IIO value into its string representation
705  * @buf:	The buffer to which the formatted value gets written
706  *		which is assumed to be big enough (i.e. PAGE_SIZE).
707  * @type:	One of the IIO_VAL_* constants. This decides how the val
708  *		and val2 parameters are formatted.
709  * @size:	Number of IIO value entries contained in vals
710  * @vals:	Pointer to the values, exact meaning depends on the
711  *		type parameter.
712  *
713  * Returns:
714  * 0 by default, a negative number on failure or the total number of characters
715  * written for a type that belongs to the IIO_VAL_* constant.
716  */
717 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
718 {
719 	ssize_t len;
720 
721 	len = __iio_format_value(buf, 0, type, size, vals);
722 	if (len >= PAGE_SIZE - 1)
723 		return -EFBIG;
724 
725 	return len + sysfs_emit_at(buf, len, "\n");
726 }
727 EXPORT_SYMBOL_GPL(iio_format_value);
728 
729 static ssize_t iio_read_channel_label(struct device *dev,
730 				      struct device_attribute *attr,
731 				      char *buf)
732 {
733 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
734 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
735 
736 	if (indio_dev->info->read_label)
737 		return indio_dev->info->read_label(indio_dev, this_attr->c, buf);
738 
739 	if (this_attr->c->extend_name)
740 		return sysfs_emit(buf, "%s\n", this_attr->c->extend_name);
741 
742 	return -EINVAL;
743 }
744 
745 static ssize_t iio_read_channel_info(struct device *dev,
746 				     struct device_attribute *attr,
747 				     char *buf)
748 {
749 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
750 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
751 	int vals[INDIO_MAX_RAW_ELEMENTS];
752 	int ret;
753 	int val_len = 2;
754 
755 	if (indio_dev->info->read_raw_multi)
756 		ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
757 							INDIO_MAX_RAW_ELEMENTS,
758 							vals, &val_len,
759 							this_attr->address);
760 	else
761 		ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
762 				    &vals[0], &vals[1], this_attr->address);
763 
764 	if (ret < 0)
765 		return ret;
766 
767 	return iio_format_value(buf, ret, val_len, vals);
768 }
769 
770 static ssize_t iio_format_list(char *buf, const int *vals, int type, int length,
771 			       const char *prefix, const char *suffix)
772 {
773 	ssize_t len;
774 	int stride;
775 	int i;
776 
777 	switch (type) {
778 	case IIO_VAL_INT:
779 		stride = 1;
780 		break;
781 	default:
782 		stride = 2;
783 		break;
784 	}
785 
786 	len = sysfs_emit(buf, prefix);
787 
788 	for (i = 0; i <= length - stride; i += stride) {
789 		if (i != 0) {
790 			len += sysfs_emit_at(buf, len, " ");
791 			if (len >= PAGE_SIZE)
792 				return -EFBIG;
793 		}
794 
795 		len += __iio_format_value(buf, len, type, stride, &vals[i]);
796 		if (len >= PAGE_SIZE)
797 			return -EFBIG;
798 	}
799 
800 	len += sysfs_emit_at(buf, len, "%s\n", suffix);
801 
802 	return len;
803 }
804 
805 static ssize_t iio_format_avail_list(char *buf, const int *vals,
806 				     int type, int length)
807 {
808 
809 	return iio_format_list(buf, vals, type, length, "", "");
810 }
811 
812 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
813 {
814 	int length;
815 
816 	/*
817 	 * length refers to the array size , not the number of elements.
818 	 * The purpose is to print the range [min , step ,max] so length should
819 	 * be 3 in case of int, and 6 for other types.
820 	 */
821 	switch (type) {
822 	case IIO_VAL_INT:
823 		length = 3;
824 		break;
825 	default:
826 		length = 6;
827 		break;
828 	}
829 
830 	return iio_format_list(buf, vals, type, length, "[", "]");
831 }
832 
833 static ssize_t iio_read_channel_info_avail(struct device *dev,
834 					   struct device_attribute *attr,
835 					   char *buf)
836 {
837 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
838 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
839 	const int *vals;
840 	int ret;
841 	int length;
842 	int type;
843 
844 	ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
845 					  &vals, &type, &length,
846 					  this_attr->address);
847 
848 	if (ret < 0)
849 		return ret;
850 	switch (ret) {
851 	case IIO_AVAIL_LIST:
852 		return iio_format_avail_list(buf, vals, type, length);
853 	case IIO_AVAIL_RANGE:
854 		return iio_format_avail_range(buf, vals, type);
855 	default:
856 		return -EINVAL;
857 	}
858 }
859 
860 /**
861  * __iio_str_to_fixpoint() - Parse a fixed-point number from a string
862  * @str: The string to parse
863  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
864  * @integer: The integer part of the number
865  * @fract: The fractional part of the number
866  * @scale_db: True if this should parse as dB
867  *
868  * Returns:
869  * 0 on success, or a negative error code if the string could not be parsed.
870  */
871 static int __iio_str_to_fixpoint(const char *str, int fract_mult,
872 				 int *integer, int *fract, bool scale_db)
873 {
874 	int i = 0, f = 0;
875 	bool integer_part = true, negative = false;
876 
877 	if (fract_mult == 0) {
878 		*fract = 0;
879 
880 		return kstrtoint(str, 0, integer);
881 	}
882 
883 	if (str[0] == '-') {
884 		negative = true;
885 		str++;
886 	} else if (str[0] == '+') {
887 		str++;
888 	}
889 
890 	while (*str) {
891 		if ('0' <= *str && *str <= '9') {
892 			if (integer_part) {
893 				i = i * 10 + *str - '0';
894 			} else {
895 				f += fract_mult * (*str - '0');
896 				fract_mult /= 10;
897 			}
898 		} else if (*str == '\n') {
899 			if (*(str + 1) == '\0')
900 				break;
901 			return -EINVAL;
902 		} else if (!strncmp(str, " dB", sizeof(" dB") - 1) && scale_db) {
903 			/* Ignore the dB suffix */
904 			str += sizeof(" dB") - 1;
905 			continue;
906 		} else if (!strncmp(str, "dB", sizeof("dB") - 1) && scale_db) {
907 			/* Ignore the dB suffix */
908 			str += sizeof("dB") - 1;
909 			continue;
910 		} else if (*str == '.' && integer_part) {
911 			integer_part = false;
912 		} else {
913 			return -EINVAL;
914 		}
915 		str++;
916 	}
917 
918 	if (negative) {
919 		if (i)
920 			i = -i;
921 		else
922 			f = -f;
923 	}
924 
925 	*integer = i;
926 	*fract = f;
927 
928 	return 0;
929 }
930 
931 /**
932  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
933  * @str: The string to parse
934  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
935  * @integer: The integer part of the number
936  * @fract: The fractional part of the number
937  *
938  * Returns:
939  * 0 on success, or a negative error code if the string could not be parsed.
940  */
941 int iio_str_to_fixpoint(const char *str, int fract_mult,
942 			int *integer, int *fract)
943 {
944 	return __iio_str_to_fixpoint(str, fract_mult, integer, fract, false);
945 }
946 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
947 
948 static ssize_t iio_write_channel_info(struct device *dev,
949 				      struct device_attribute *attr,
950 				      const char *buf,
951 				      size_t len)
952 {
953 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
954 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
955 	int ret, fract_mult = 100000;
956 	int integer, fract = 0;
957 	bool is_char = false;
958 	bool scale_db = false;
959 
960 	/* Assumes decimal - precision based on number of digits */
961 	if (!indio_dev->info->write_raw)
962 		return -EINVAL;
963 
964 	if (indio_dev->info->write_raw_get_fmt)
965 		switch (indio_dev->info->write_raw_get_fmt(indio_dev,
966 			this_attr->c, this_attr->address)) {
967 		case IIO_VAL_INT:
968 			fract_mult = 0;
969 			break;
970 		case IIO_VAL_INT_PLUS_MICRO_DB:
971 			scale_db = true;
972 			fallthrough;
973 		case IIO_VAL_INT_PLUS_MICRO:
974 			fract_mult = 100000;
975 			break;
976 		case IIO_VAL_INT_PLUS_NANO:
977 			fract_mult = 100000000;
978 			break;
979 		case IIO_VAL_CHAR:
980 			is_char = true;
981 			break;
982 		default:
983 			return -EINVAL;
984 		}
985 
986 	if (is_char) {
987 		char ch;
988 
989 		if (sscanf(buf, "%c", &ch) != 1)
990 			return -EINVAL;
991 		integer = ch;
992 	} else {
993 		ret = __iio_str_to_fixpoint(buf, fract_mult, &integer, &fract,
994 					    scale_db);
995 		if (ret)
996 			return ret;
997 	}
998 
999 	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
1000 					 integer, fract, this_attr->address);
1001 	if (ret)
1002 		return ret;
1003 
1004 	return len;
1005 }
1006 
1007 static
1008 int __iio_device_attr_init(struct device_attribute *dev_attr,
1009 			   const char *postfix,
1010 			   struct iio_chan_spec const *chan,
1011 			   ssize_t (*readfunc)(struct device *dev,
1012 					       struct device_attribute *attr,
1013 					       char *buf),
1014 			   ssize_t (*writefunc)(struct device *dev,
1015 						struct device_attribute *attr,
1016 						const char *buf,
1017 						size_t len),
1018 			   enum iio_shared_by shared_by)
1019 {
1020 	int ret = 0;
1021 	char *name = NULL;
1022 	char *full_postfix;
1023 
1024 	sysfs_attr_init(&dev_attr->attr);
1025 
1026 	/* Build up postfix of <extend_name>_<modifier>_postfix */
1027 	if (chan->modified && (shared_by == IIO_SEPARATE)) {
1028 		if (chan->extend_name)
1029 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
1030 						 iio_modifier_names[chan->channel2],
1031 						 chan->extend_name,
1032 						 postfix);
1033 		else
1034 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
1035 						 iio_modifier_names[chan->channel2],
1036 						 postfix);
1037 	} else {
1038 		if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
1039 			full_postfix = kstrdup(postfix, GFP_KERNEL);
1040 		else
1041 			full_postfix = kasprintf(GFP_KERNEL,
1042 						 "%s_%s",
1043 						 chan->extend_name,
1044 						 postfix);
1045 	}
1046 	if (full_postfix == NULL)
1047 		return -ENOMEM;
1048 
1049 	if (chan->differential) { /* Differential can not have modifier */
1050 		switch (shared_by) {
1051 		case IIO_SHARED_BY_ALL:
1052 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
1053 			break;
1054 		case IIO_SHARED_BY_DIR:
1055 			name = kasprintf(GFP_KERNEL, "%s_%s",
1056 						iio_direction[chan->output],
1057 						full_postfix);
1058 			break;
1059 		case IIO_SHARED_BY_TYPE:
1060 			name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
1061 					    iio_direction[chan->output],
1062 					    iio_chan_type_name_spec[chan->type],
1063 					    iio_chan_type_name_spec[chan->type],
1064 					    full_postfix);
1065 			break;
1066 		case IIO_SEPARATE:
1067 			if (!chan->indexed) {
1068 				WARN(1, "Differential channels must be indexed\n");
1069 				ret = -EINVAL;
1070 				goto error_free_full_postfix;
1071 			}
1072 			name = kasprintf(GFP_KERNEL,
1073 					    "%s_%s%d-%s%d_%s",
1074 					    iio_direction[chan->output],
1075 					    iio_chan_type_name_spec[chan->type],
1076 					    chan->channel,
1077 					    iio_chan_type_name_spec[chan->type],
1078 					    chan->channel2,
1079 					    full_postfix);
1080 			break;
1081 		}
1082 	} else { /* Single ended */
1083 		switch (shared_by) {
1084 		case IIO_SHARED_BY_ALL:
1085 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
1086 			break;
1087 		case IIO_SHARED_BY_DIR:
1088 			name = kasprintf(GFP_KERNEL, "%s_%s",
1089 						iio_direction[chan->output],
1090 						full_postfix);
1091 			break;
1092 		case IIO_SHARED_BY_TYPE:
1093 			name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1094 					    iio_direction[chan->output],
1095 					    iio_chan_type_name_spec[chan->type],
1096 					    full_postfix);
1097 			break;
1098 
1099 		case IIO_SEPARATE:
1100 			if (chan->indexed)
1101 				name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
1102 						    iio_direction[chan->output],
1103 						    iio_chan_type_name_spec[chan->type],
1104 						    chan->channel,
1105 						    full_postfix);
1106 			else
1107 				name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1108 						    iio_direction[chan->output],
1109 						    iio_chan_type_name_spec[chan->type],
1110 						    full_postfix);
1111 			break;
1112 		}
1113 	}
1114 	if (name == NULL) {
1115 		ret = -ENOMEM;
1116 		goto error_free_full_postfix;
1117 	}
1118 	dev_attr->attr.name = name;
1119 
1120 	if (readfunc) {
1121 		dev_attr->attr.mode |= 0444;
1122 		dev_attr->show = readfunc;
1123 	}
1124 
1125 	if (writefunc) {
1126 		dev_attr->attr.mode |= 0200;
1127 		dev_attr->store = writefunc;
1128 	}
1129 
1130 error_free_full_postfix:
1131 	kfree(full_postfix);
1132 
1133 	return ret;
1134 }
1135 
1136 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1137 {
1138 	kfree(dev_attr->attr.name);
1139 }
1140 
1141 int __iio_add_chan_devattr(const char *postfix,
1142 			   struct iio_chan_spec const *chan,
1143 			   ssize_t (*readfunc)(struct device *dev,
1144 					       struct device_attribute *attr,
1145 					       char *buf),
1146 			   ssize_t (*writefunc)(struct device *dev,
1147 						struct device_attribute *attr,
1148 						const char *buf,
1149 						size_t len),
1150 			   u64 mask,
1151 			   enum iio_shared_by shared_by,
1152 			   struct device *dev,
1153 			   struct iio_buffer *buffer,
1154 			   struct list_head *attr_list)
1155 {
1156 	int ret;
1157 	struct iio_dev_attr *iio_attr, *t;
1158 
1159 	iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1160 	if (iio_attr == NULL)
1161 		return -ENOMEM;
1162 	ret = __iio_device_attr_init(&iio_attr->dev_attr,
1163 				     postfix, chan,
1164 				     readfunc, writefunc, shared_by);
1165 	if (ret)
1166 		goto error_iio_dev_attr_free;
1167 	iio_attr->c = chan;
1168 	iio_attr->address = mask;
1169 	iio_attr->buffer = buffer;
1170 	list_for_each_entry(t, attr_list, l)
1171 		if (strcmp(t->dev_attr.attr.name,
1172 			   iio_attr->dev_attr.attr.name) == 0) {
1173 			if (shared_by == IIO_SEPARATE)
1174 				dev_err(dev, "tried to double register : %s\n",
1175 					t->dev_attr.attr.name);
1176 			ret = -EBUSY;
1177 			goto error_device_attr_deinit;
1178 		}
1179 	list_add(&iio_attr->l, attr_list);
1180 
1181 	return 0;
1182 
1183 error_device_attr_deinit:
1184 	__iio_device_attr_deinit(&iio_attr->dev_attr);
1185 error_iio_dev_attr_free:
1186 	kfree(iio_attr);
1187 	return ret;
1188 }
1189 
1190 static int iio_device_add_channel_label(struct iio_dev *indio_dev,
1191 					 struct iio_chan_spec const *chan)
1192 {
1193 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1194 	int ret;
1195 
1196 	if (!indio_dev->info->read_label && !chan->extend_name)
1197 		return 0;
1198 
1199 	ret = __iio_add_chan_devattr("label",
1200 				     chan,
1201 				     &iio_read_channel_label,
1202 				     NULL,
1203 				     0,
1204 				     IIO_SEPARATE,
1205 				     &indio_dev->dev,
1206 				     NULL,
1207 				     &iio_dev_opaque->channel_attr_list);
1208 	if (ret < 0)
1209 		return ret;
1210 
1211 	return 1;
1212 }
1213 
1214 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1215 					 struct iio_chan_spec const *chan,
1216 					 enum iio_shared_by shared_by,
1217 					 const long *infomask)
1218 {
1219 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1220 	int i, ret, attrcount = 0;
1221 
1222 	for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1223 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1224 			return -EINVAL;
1225 		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1226 					     chan,
1227 					     &iio_read_channel_info,
1228 					     &iio_write_channel_info,
1229 					     i,
1230 					     shared_by,
1231 					     &indio_dev->dev,
1232 					     NULL,
1233 					     &iio_dev_opaque->channel_attr_list);
1234 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1235 			continue;
1236 		if (ret < 0)
1237 			return ret;
1238 		attrcount++;
1239 	}
1240 
1241 	return attrcount;
1242 }
1243 
1244 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1245 					       struct iio_chan_spec const *chan,
1246 					       enum iio_shared_by shared_by,
1247 					       const long *infomask)
1248 {
1249 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1250 	int i, ret, attrcount = 0;
1251 	char *avail_postfix;
1252 
1253 	for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1254 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1255 			return -EINVAL;
1256 		avail_postfix = kasprintf(GFP_KERNEL,
1257 					  "%s_available",
1258 					  iio_chan_info_postfix[i]);
1259 		if (!avail_postfix)
1260 			return -ENOMEM;
1261 
1262 		ret = __iio_add_chan_devattr(avail_postfix,
1263 					     chan,
1264 					     &iio_read_channel_info_avail,
1265 					     NULL,
1266 					     i,
1267 					     shared_by,
1268 					     &indio_dev->dev,
1269 					     NULL,
1270 					     &iio_dev_opaque->channel_attr_list);
1271 		kfree(avail_postfix);
1272 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1273 			continue;
1274 		if (ret < 0)
1275 			return ret;
1276 		attrcount++;
1277 	}
1278 
1279 	return attrcount;
1280 }
1281 
1282 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1283 					struct iio_chan_spec const *chan)
1284 {
1285 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1286 	int ret, attrcount = 0;
1287 	const struct iio_chan_spec_ext_info *ext_info;
1288 
1289 	if (chan->channel < 0)
1290 		return 0;
1291 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1292 					    IIO_SEPARATE,
1293 					    &chan->info_mask_separate);
1294 	if (ret < 0)
1295 		return ret;
1296 	attrcount += ret;
1297 
1298 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1299 						  IIO_SEPARATE,
1300 						  &chan->info_mask_separate_available);
1301 	if (ret < 0)
1302 		return ret;
1303 	attrcount += ret;
1304 
1305 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1306 					    IIO_SHARED_BY_TYPE,
1307 					    &chan->info_mask_shared_by_type);
1308 	if (ret < 0)
1309 		return ret;
1310 	attrcount += ret;
1311 
1312 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1313 						  IIO_SHARED_BY_TYPE,
1314 						  &chan->info_mask_shared_by_type_available);
1315 	if (ret < 0)
1316 		return ret;
1317 	attrcount += ret;
1318 
1319 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1320 					    IIO_SHARED_BY_DIR,
1321 					    &chan->info_mask_shared_by_dir);
1322 	if (ret < 0)
1323 		return ret;
1324 	attrcount += ret;
1325 
1326 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1327 						  IIO_SHARED_BY_DIR,
1328 						  &chan->info_mask_shared_by_dir_available);
1329 	if (ret < 0)
1330 		return ret;
1331 	attrcount += ret;
1332 
1333 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1334 					    IIO_SHARED_BY_ALL,
1335 					    &chan->info_mask_shared_by_all);
1336 	if (ret < 0)
1337 		return ret;
1338 	attrcount += ret;
1339 
1340 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1341 						  IIO_SHARED_BY_ALL,
1342 						  &chan->info_mask_shared_by_all_available);
1343 	if (ret < 0)
1344 		return ret;
1345 	attrcount += ret;
1346 
1347 	ret = iio_device_add_channel_label(indio_dev, chan);
1348 	if (ret < 0)
1349 		return ret;
1350 	attrcount += ret;
1351 
1352 	if (chan->ext_info) {
1353 		unsigned int i = 0;
1354 
1355 		for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1356 			ret = __iio_add_chan_devattr(ext_info->name,
1357 					chan,
1358 					ext_info->read ?
1359 					    &iio_read_channel_ext_info : NULL,
1360 					ext_info->write ?
1361 					    &iio_write_channel_ext_info : NULL,
1362 					i,
1363 					ext_info->shared,
1364 					&indio_dev->dev,
1365 					NULL,
1366 					&iio_dev_opaque->channel_attr_list);
1367 			i++;
1368 			if (ret == -EBUSY && ext_info->shared)
1369 				continue;
1370 
1371 			if (ret)
1372 				return ret;
1373 
1374 			attrcount++;
1375 		}
1376 	}
1377 
1378 	return attrcount;
1379 }
1380 
1381 /**
1382  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1383  * @attr_list: List of IIO device attributes
1384  *
1385  * This function frees the memory allocated for each of the IIO device
1386  * attributes in the list.
1387  */
1388 void iio_free_chan_devattr_list(struct list_head *attr_list)
1389 {
1390 	struct iio_dev_attr *p, *n;
1391 
1392 	list_for_each_entry_safe(p, n, attr_list, l) {
1393 		kfree_const(p->dev_attr.attr.name);
1394 		list_del(&p->l);
1395 		kfree(p);
1396 	}
1397 }
1398 
1399 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
1400 			 char *buf)
1401 {
1402 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1403 
1404 	return sysfs_emit(buf, "%s\n", indio_dev->name);
1405 }
1406 
1407 static DEVICE_ATTR_RO(name);
1408 
1409 static ssize_t label_show(struct device *dev, struct device_attribute *attr,
1410 			  char *buf)
1411 {
1412 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1413 
1414 	return sysfs_emit(buf, "%s\n", indio_dev->label);
1415 }
1416 
1417 static DEVICE_ATTR_RO(label);
1418 
1419 static const char * const clock_names[] = {
1420 	[CLOCK_REALTIME]	 	= "realtime",
1421 	[CLOCK_MONOTONIC]	 	= "monotonic",
1422 	[CLOCK_PROCESS_CPUTIME_ID]	= "process_cputime_id",
1423 	[CLOCK_THREAD_CPUTIME_ID]	= "thread_cputime_id",
1424 	[CLOCK_MONOTONIC_RAW]	 	= "monotonic_raw",
1425 	[CLOCK_REALTIME_COARSE]	 	= "realtime_coarse",
1426 	[CLOCK_MONOTONIC_COARSE] 	= "monotonic_coarse",
1427 	[CLOCK_BOOTTIME]	 	= "boottime",
1428 	[CLOCK_REALTIME_ALARM]		= "realtime_alarm",
1429 	[CLOCK_BOOTTIME_ALARM]		= "boottime_alarm",
1430 	[CLOCK_SGI_CYCLE]		= "sgi_cycle",
1431 	[CLOCK_TAI]		 	= "tai",
1432 };
1433 
1434 static ssize_t current_timestamp_clock_show(struct device *dev,
1435 					    struct device_attribute *attr,
1436 					    char *buf)
1437 {
1438 	const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1439 	const clockid_t clk = iio_device_get_clock(indio_dev);
1440 
1441 	switch (clk) {
1442 	case CLOCK_REALTIME:
1443 	case CLOCK_MONOTONIC:
1444 	case CLOCK_MONOTONIC_RAW:
1445 	case CLOCK_REALTIME_COARSE:
1446 	case CLOCK_MONOTONIC_COARSE:
1447 	case CLOCK_BOOTTIME:
1448 	case CLOCK_TAI:
1449 		break;
1450 	default:
1451 		BUG();
1452 	}
1453 
1454 	return sysfs_emit(buf, "%s\n", clock_names[clk]);
1455 }
1456 
1457 static ssize_t current_timestamp_clock_store(struct device *dev,
1458 					     struct device_attribute *attr,
1459 					     const char *buf, size_t len)
1460 {
1461 	clockid_t clk;
1462 	int ret;
1463 
1464 	ret = sysfs_match_string(clock_names, buf);
1465 	if (ret < 0)
1466 		return ret;
1467 	clk = ret;
1468 
1469 	switch (clk) {
1470 	case CLOCK_REALTIME:
1471 	case CLOCK_MONOTONIC:
1472 	case CLOCK_MONOTONIC_RAW:
1473 	case CLOCK_REALTIME_COARSE:
1474 	case CLOCK_MONOTONIC_COARSE:
1475 	case CLOCK_BOOTTIME:
1476 	case CLOCK_TAI:
1477 		break;
1478 	default:
1479 		return -EINVAL;
1480 	}
1481 
1482 	ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1483 	if (ret)
1484 		return ret;
1485 
1486 	return len;
1487 }
1488 
1489 int iio_device_register_sysfs_group(struct iio_dev *indio_dev,
1490 				    const struct attribute_group *group)
1491 {
1492 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1493 	const struct attribute_group **new, **old = iio_dev_opaque->groups;
1494 	unsigned int cnt = iio_dev_opaque->groupcounter;
1495 
1496 	new = krealloc_array(old, cnt + 2, sizeof(*new), GFP_KERNEL);
1497 	if (!new)
1498 		return -ENOMEM;
1499 
1500 	new[iio_dev_opaque->groupcounter++] = group;
1501 	new[iio_dev_opaque->groupcounter] = NULL;
1502 
1503 	iio_dev_opaque->groups = new;
1504 
1505 	return 0;
1506 }
1507 
1508 static DEVICE_ATTR_RW(current_timestamp_clock);
1509 
1510 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1511 {
1512 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1513 	int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1514 	struct iio_dev_attr *p;
1515 	struct attribute **attr, *clk = NULL;
1516 
1517 	/* First count elements in any existing group */
1518 	if (indio_dev->info->attrs) {
1519 		attr = indio_dev->info->attrs->attrs;
1520 		while (*attr++ != NULL)
1521 			attrcount_orig++;
1522 	}
1523 	attrcount = attrcount_orig;
1524 	/*
1525 	 * New channel registration method - relies on the fact a group does
1526 	 * not need to be initialized if its name is NULL.
1527 	 */
1528 	if (indio_dev->channels)
1529 		for (i = 0; i < indio_dev->num_channels; i++) {
1530 			const struct iio_chan_spec *chan =
1531 				&indio_dev->channels[i];
1532 
1533 			if (chan->type == IIO_TIMESTAMP)
1534 				clk = &dev_attr_current_timestamp_clock.attr;
1535 
1536 			ret = iio_device_add_channel_sysfs(indio_dev, chan);
1537 			if (ret < 0)
1538 				goto error_clear_attrs;
1539 			attrcount += ret;
1540 		}
1541 
1542 	if (iio_dev_opaque->event_interface)
1543 		clk = &dev_attr_current_timestamp_clock.attr;
1544 
1545 	if (indio_dev->name)
1546 		attrcount++;
1547 	if (indio_dev->label)
1548 		attrcount++;
1549 	if (clk)
1550 		attrcount++;
1551 
1552 	iio_dev_opaque->chan_attr_group.attrs =
1553 		kcalloc(attrcount + 1,
1554 			sizeof(iio_dev_opaque->chan_attr_group.attrs[0]),
1555 			GFP_KERNEL);
1556 	if (iio_dev_opaque->chan_attr_group.attrs == NULL) {
1557 		ret = -ENOMEM;
1558 		goto error_clear_attrs;
1559 	}
1560 	/* Copy across original attributes, and point to original binary attributes */
1561 	if (indio_dev->info->attrs) {
1562 		memcpy(iio_dev_opaque->chan_attr_group.attrs,
1563 		       indio_dev->info->attrs->attrs,
1564 		       sizeof(iio_dev_opaque->chan_attr_group.attrs[0])
1565 		       *attrcount_orig);
1566 		iio_dev_opaque->chan_attr_group.is_visible =
1567 			indio_dev->info->attrs->is_visible;
1568 		iio_dev_opaque->chan_attr_group.bin_attrs =
1569 			indio_dev->info->attrs->bin_attrs;
1570 	}
1571 	attrn = attrcount_orig;
1572 	/* Add all elements from the list. */
1573 	list_for_each_entry(p, &iio_dev_opaque->channel_attr_list, l)
1574 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1575 	if (indio_dev->name)
1576 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1577 	if (indio_dev->label)
1578 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &dev_attr_label.attr;
1579 	if (clk)
1580 		iio_dev_opaque->chan_attr_group.attrs[attrn++] = clk;
1581 
1582 	ret = iio_device_register_sysfs_group(indio_dev,
1583 					      &iio_dev_opaque->chan_attr_group);
1584 	if (ret)
1585 		goto error_free_chan_attrs;
1586 
1587 	return 0;
1588 
1589 error_free_chan_attrs:
1590 	kfree(iio_dev_opaque->chan_attr_group.attrs);
1591 	iio_dev_opaque->chan_attr_group.attrs = NULL;
1592 error_clear_attrs:
1593 	iio_free_chan_devattr_list(&iio_dev_opaque->channel_attr_list);
1594 
1595 	return ret;
1596 }
1597 
1598 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1599 {
1600 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1601 
1602 	iio_free_chan_devattr_list(&iio_dev_opaque->channel_attr_list);
1603 	kfree(iio_dev_opaque->chan_attr_group.attrs);
1604 	iio_dev_opaque->chan_attr_group.attrs = NULL;
1605 	kfree(iio_dev_opaque->groups);
1606 	iio_dev_opaque->groups = NULL;
1607 }
1608 
1609 static void iio_dev_release(struct device *device)
1610 {
1611 	struct iio_dev *indio_dev = dev_to_iio_dev(device);
1612 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1613 
1614 	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1615 		iio_device_unregister_trigger_consumer(indio_dev);
1616 	iio_device_unregister_eventset(indio_dev);
1617 	iio_device_unregister_sysfs(indio_dev);
1618 
1619 	iio_device_detach_buffers(indio_dev);
1620 
1621 	lockdep_unregister_key(&iio_dev_opaque->mlock_key);
1622 
1623 	ida_free(&iio_ida, iio_dev_opaque->id);
1624 	kfree(iio_dev_opaque);
1625 }
1626 
1627 const struct device_type iio_device_type = {
1628 	.name = "iio_device",
1629 	.release = iio_dev_release,
1630 };
1631 
1632 /**
1633  * iio_device_alloc() - allocate an iio_dev from a driver
1634  * @parent:		Parent device.
1635  * @sizeof_priv:	Space to allocate for private structure.
1636  *
1637  * Returns:
1638  * Pointer to allocated iio_dev on success, NULL on failure.
1639  */
1640 struct iio_dev *iio_device_alloc(struct device *parent, int sizeof_priv)
1641 {
1642 	struct iio_dev_opaque *iio_dev_opaque;
1643 	struct iio_dev *indio_dev;
1644 	size_t alloc_size;
1645 
1646 	alloc_size = sizeof(struct iio_dev_opaque);
1647 	if (sizeof_priv) {
1648 		alloc_size = ALIGN(alloc_size, IIO_DMA_MINALIGN);
1649 		alloc_size += sizeof_priv;
1650 	}
1651 
1652 	iio_dev_opaque = kzalloc(alloc_size, GFP_KERNEL);
1653 	if (!iio_dev_opaque)
1654 		return NULL;
1655 
1656 	indio_dev = &iio_dev_opaque->indio_dev;
1657 	indio_dev->priv = (char *)iio_dev_opaque +
1658 		ALIGN(sizeof(struct iio_dev_opaque), IIO_DMA_MINALIGN);
1659 
1660 	indio_dev->dev.parent = parent;
1661 	indio_dev->dev.type = &iio_device_type;
1662 	indio_dev->dev.bus = &iio_bus_type;
1663 	device_initialize(&indio_dev->dev);
1664 	mutex_init(&iio_dev_opaque->mlock);
1665 	mutex_init(&iio_dev_opaque->info_exist_lock);
1666 	INIT_LIST_HEAD(&iio_dev_opaque->channel_attr_list);
1667 
1668 	iio_dev_opaque->id = ida_alloc(&iio_ida, GFP_KERNEL);
1669 	if (iio_dev_opaque->id < 0) {
1670 		/* cannot use a dev_err as the name isn't available */
1671 		pr_err("failed to get device id\n");
1672 		kfree(iio_dev_opaque);
1673 		return NULL;
1674 	}
1675 
1676 	if (dev_set_name(&indio_dev->dev, "iio:device%d", iio_dev_opaque->id)) {
1677 		ida_free(&iio_ida, iio_dev_opaque->id);
1678 		kfree(iio_dev_opaque);
1679 		return NULL;
1680 	}
1681 
1682 	INIT_LIST_HEAD(&iio_dev_opaque->buffer_list);
1683 	INIT_LIST_HEAD(&iio_dev_opaque->ioctl_handlers);
1684 
1685 	lockdep_register_key(&iio_dev_opaque->mlock_key);
1686 	lockdep_set_class(&iio_dev_opaque->mlock, &iio_dev_opaque->mlock_key);
1687 
1688 	return indio_dev;
1689 }
1690 EXPORT_SYMBOL(iio_device_alloc);
1691 
1692 /**
1693  * iio_device_free() - free an iio_dev from a driver
1694  * @dev:		the iio_dev associated with the device
1695  */
1696 void iio_device_free(struct iio_dev *dev)
1697 {
1698 	if (dev)
1699 		put_device(&dev->dev);
1700 }
1701 EXPORT_SYMBOL(iio_device_free);
1702 
1703 static void devm_iio_device_release(void *iio_dev)
1704 {
1705 	iio_device_free(iio_dev);
1706 }
1707 
1708 /**
1709  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1710  * @parent:		Device to allocate iio_dev for, and parent for this IIO device
1711  * @sizeof_priv:	Space to allocate for private structure.
1712  *
1713  * Managed iio_device_alloc. iio_dev allocated with this function is
1714  * automatically freed on driver detach.
1715  *
1716  * Returns:
1717  * Pointer to allocated iio_dev on success, NULL on failure.
1718  */
1719 struct iio_dev *devm_iio_device_alloc(struct device *parent, int sizeof_priv)
1720 {
1721 	struct iio_dev *iio_dev;
1722 	int ret;
1723 
1724 	iio_dev = iio_device_alloc(parent, sizeof_priv);
1725 	if (!iio_dev)
1726 		return NULL;
1727 
1728 	ret = devm_add_action_or_reset(parent, devm_iio_device_release,
1729 				       iio_dev);
1730 	if (ret)
1731 		return NULL;
1732 
1733 	return iio_dev;
1734 }
1735 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1736 
1737 /**
1738  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1739  * @inode:	Inode structure for identifying the device in the file system
1740  * @filp:	File structure for iio device used to keep and later access
1741  *		private data
1742  *
1743  * Returns: 0 on success or -EBUSY if the device is already opened
1744  */
1745 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1746 {
1747 	struct iio_dev_opaque *iio_dev_opaque =
1748 		container_of(inode->i_cdev, struct iio_dev_opaque, chrdev);
1749 	struct iio_dev *indio_dev = &iio_dev_opaque->indio_dev;
1750 	struct iio_dev_buffer_pair *ib;
1751 
1752 	if (test_and_set_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags))
1753 		return -EBUSY;
1754 
1755 	iio_device_get(indio_dev);
1756 
1757 	ib = kmalloc(sizeof(*ib), GFP_KERNEL);
1758 	if (!ib) {
1759 		iio_device_put(indio_dev);
1760 		clear_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags);
1761 		return -ENOMEM;
1762 	}
1763 
1764 	ib->indio_dev = indio_dev;
1765 	ib->buffer = indio_dev->buffer;
1766 
1767 	filp->private_data = ib;
1768 
1769 	return 0;
1770 }
1771 
1772 /**
1773  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1774  * @inode:	Inode structure pointer for the char device
1775  * @filp:	File structure pointer for the char device
1776  *
1777  * Returns: 0 for successful release.
1778  */
1779 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1780 {
1781 	struct iio_dev_buffer_pair *ib = filp->private_data;
1782 	struct iio_dev_opaque *iio_dev_opaque =
1783 		container_of(inode->i_cdev, struct iio_dev_opaque, chrdev);
1784 	struct iio_dev *indio_dev = &iio_dev_opaque->indio_dev;
1785 
1786 	kfree(ib);
1787 	clear_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags);
1788 	iio_device_put(indio_dev);
1789 
1790 	return 0;
1791 }
1792 
1793 void iio_device_ioctl_handler_register(struct iio_dev *indio_dev,
1794 				       struct iio_ioctl_handler *h)
1795 {
1796 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1797 
1798 	list_add_tail(&h->entry, &iio_dev_opaque->ioctl_handlers);
1799 }
1800 
1801 void iio_device_ioctl_handler_unregister(struct iio_ioctl_handler *h)
1802 {
1803 	list_del(&h->entry);
1804 }
1805 
1806 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1807 {
1808 	struct iio_dev_buffer_pair *ib = filp->private_data;
1809 	struct iio_dev *indio_dev = ib->indio_dev;
1810 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1811 	struct iio_ioctl_handler *h;
1812 	int ret = -ENODEV;
1813 
1814 	mutex_lock(&iio_dev_opaque->info_exist_lock);
1815 
1816 	/*
1817 	 * The NULL check here is required to prevent crashing when a device
1818 	 * is being removed while userspace would still have open file handles
1819 	 * to try to access this device.
1820 	 */
1821 	if (!indio_dev->info)
1822 		goto out_unlock;
1823 
1824 	list_for_each_entry(h, &iio_dev_opaque->ioctl_handlers, entry) {
1825 		ret = h->ioctl(indio_dev, filp, cmd, arg);
1826 		if (ret != IIO_IOCTL_UNHANDLED)
1827 			break;
1828 	}
1829 
1830 	if (ret == IIO_IOCTL_UNHANDLED)
1831 		ret = -ENODEV;
1832 
1833 out_unlock:
1834 	mutex_unlock(&iio_dev_opaque->info_exist_lock);
1835 
1836 	return ret;
1837 }
1838 
1839 static const struct file_operations iio_buffer_fileops = {
1840 	.owner = THIS_MODULE,
1841 	.llseek = noop_llseek,
1842 	.read = iio_buffer_read_outer_addr,
1843 	.write = iio_buffer_write_outer_addr,
1844 	.poll = iio_buffer_poll_addr,
1845 	.unlocked_ioctl = iio_ioctl,
1846 	.compat_ioctl = compat_ptr_ioctl,
1847 	.open = iio_chrdev_open,
1848 	.release = iio_chrdev_release,
1849 };
1850 
1851 static const struct file_operations iio_event_fileops = {
1852 	.owner = THIS_MODULE,
1853 	.llseek = noop_llseek,
1854 	.unlocked_ioctl = iio_ioctl,
1855 	.compat_ioctl = compat_ptr_ioctl,
1856 	.open = iio_chrdev_open,
1857 	.release = iio_chrdev_release,
1858 };
1859 
1860 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1861 {
1862 	int i, j;
1863 	const struct iio_chan_spec *channels = indio_dev->channels;
1864 
1865 	if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1866 		return 0;
1867 
1868 	for (i = 0; i < indio_dev->num_channels - 1; i++) {
1869 		if (channels[i].scan_index < 0)
1870 			continue;
1871 		for (j = i + 1; j < indio_dev->num_channels; j++)
1872 			if (channels[i].scan_index == channels[j].scan_index) {
1873 				dev_err(&indio_dev->dev,
1874 					"Duplicate scan index %d\n",
1875 					channels[i].scan_index);
1876 				return -EINVAL;
1877 			}
1878 	}
1879 
1880 	return 0;
1881 }
1882 
1883 static int iio_check_extended_name(const struct iio_dev *indio_dev)
1884 {
1885 	unsigned int i;
1886 
1887 	if (!indio_dev->info->read_label)
1888 		return 0;
1889 
1890 	for (i = 0; i < indio_dev->num_channels; i++) {
1891 		if (indio_dev->channels[i].extend_name) {
1892 			dev_err(&indio_dev->dev,
1893 				"Cannot use labels and extend_name at the same time\n");
1894 			return -EINVAL;
1895 		}
1896 	}
1897 
1898 	return 0;
1899 }
1900 
1901 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1902 
1903 static void iio_sanity_check_avail_scan_masks(struct iio_dev *indio_dev)
1904 {
1905 	unsigned int num_masks, masklength, longs_per_mask;
1906 	const unsigned long *av_masks;
1907 	int i;
1908 
1909 	av_masks = indio_dev->available_scan_masks;
1910 	masklength = indio_dev->masklength;
1911 	longs_per_mask = BITS_TO_LONGS(masklength);
1912 
1913 	/*
1914 	 * The code determining how many available_scan_masks is in the array
1915 	 * will be assuming the end of masks when first long with all bits
1916 	 * zeroed is encountered. This is incorrect for masks where mask
1917 	 * consists of more than one long, and where some of the available masks
1918 	 * has long worth of bits zeroed (but has subsequent bit(s) set). This
1919 	 * is a safety measure against bug where array of masks is terminated by
1920 	 * a single zero while mask width is greater than width of a long.
1921 	 */
1922 	if (longs_per_mask > 1)
1923 		dev_warn(indio_dev->dev.parent,
1924 			 "multi long available scan masks not fully supported\n");
1925 
1926 	if (bitmap_empty(av_masks, masklength))
1927 		dev_warn(indio_dev->dev.parent, "empty scan mask\n");
1928 
1929 	for (num_masks = 0; *av_masks; num_masks++)
1930 		av_masks += longs_per_mask;
1931 
1932 	if (num_masks < 2)
1933 		return;
1934 
1935 	av_masks = indio_dev->available_scan_masks;
1936 
1937 	/*
1938 	 * Go through all the masks from first to one before the last, and see
1939 	 * that no mask found later from the available_scan_masks array is a
1940 	 * subset of mask found earlier. If this happens, then the mask found
1941 	 * later will never get used because scanning the array is stopped when
1942 	 * the first suitable mask is found. Drivers should order the array of
1943 	 * available masks in the order of preference (presumably the least
1944 	 * costy to access masks first).
1945 	 */
1946 	for (i = 0; i < num_masks - 1; i++) {
1947 		const unsigned long *mask1;
1948 		int j;
1949 
1950 		mask1 = av_masks + i * longs_per_mask;
1951 		for (j = i + 1; j < num_masks; j++) {
1952 			const unsigned long *mask2;
1953 
1954 			mask2 = av_masks + j * longs_per_mask;
1955 			if (bitmap_subset(mask2, mask1, masklength))
1956 				dev_warn(indio_dev->dev.parent,
1957 					 "available_scan_mask %d subset of %d. Never used\n",
1958 					 j, i);
1959 		}
1960 	}
1961 }
1962 
1963 int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1964 {
1965 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1966 	struct fwnode_handle *fwnode = NULL;
1967 	int ret;
1968 
1969 	if (!indio_dev->info)
1970 		return -EINVAL;
1971 
1972 	iio_dev_opaque->driver_module = this_mod;
1973 
1974 	/* If the calling driver did not initialize firmware node, do it here */
1975 	if (dev_fwnode(&indio_dev->dev))
1976 		fwnode = dev_fwnode(&indio_dev->dev);
1977 	/* The default dummy IIO device has no parent */
1978 	else if (indio_dev->dev.parent)
1979 		fwnode = dev_fwnode(indio_dev->dev.parent);
1980 	device_set_node(&indio_dev->dev, fwnode);
1981 
1982 	fwnode_property_read_string(fwnode, "label", &indio_dev->label);
1983 
1984 	ret = iio_check_unique_scan_index(indio_dev);
1985 	if (ret < 0)
1986 		return ret;
1987 
1988 	ret = iio_check_extended_name(indio_dev);
1989 	if (ret < 0)
1990 		return ret;
1991 
1992 	iio_device_register_debugfs(indio_dev);
1993 
1994 	ret = iio_buffers_alloc_sysfs_and_mask(indio_dev);
1995 	if (ret) {
1996 		dev_err(indio_dev->dev.parent,
1997 			"Failed to create buffer sysfs interfaces\n");
1998 		goto error_unreg_debugfs;
1999 	}
2000 
2001 	if (indio_dev->available_scan_masks)
2002 		iio_sanity_check_avail_scan_masks(indio_dev);
2003 
2004 	ret = iio_device_register_sysfs(indio_dev);
2005 	if (ret) {
2006 		dev_err(indio_dev->dev.parent,
2007 			"Failed to register sysfs interfaces\n");
2008 		goto error_buffer_free_sysfs;
2009 	}
2010 	ret = iio_device_register_eventset(indio_dev);
2011 	if (ret) {
2012 		dev_err(indio_dev->dev.parent,
2013 			"Failed to register event set\n");
2014 		goto error_free_sysfs;
2015 	}
2016 	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
2017 		iio_device_register_trigger_consumer(indio_dev);
2018 
2019 	if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
2020 		indio_dev->setup_ops == NULL)
2021 		indio_dev->setup_ops = &noop_ring_setup_ops;
2022 
2023 	if (iio_dev_opaque->attached_buffers_cnt)
2024 		cdev_init(&iio_dev_opaque->chrdev, &iio_buffer_fileops);
2025 	else if (iio_dev_opaque->event_interface)
2026 		cdev_init(&iio_dev_opaque->chrdev, &iio_event_fileops);
2027 
2028 	if (iio_dev_opaque->attached_buffers_cnt || iio_dev_opaque->event_interface) {
2029 		indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), iio_dev_opaque->id);
2030 		iio_dev_opaque->chrdev.owner = this_mod;
2031 	}
2032 
2033 	/* assign device groups now; they should be all registered now */
2034 	indio_dev->dev.groups = iio_dev_opaque->groups;
2035 
2036 	ret = cdev_device_add(&iio_dev_opaque->chrdev, &indio_dev->dev);
2037 	if (ret < 0)
2038 		goto error_unreg_eventset;
2039 
2040 	return 0;
2041 
2042 error_unreg_eventset:
2043 	iio_device_unregister_eventset(indio_dev);
2044 error_free_sysfs:
2045 	iio_device_unregister_sysfs(indio_dev);
2046 error_buffer_free_sysfs:
2047 	iio_buffers_free_sysfs_and_mask(indio_dev);
2048 error_unreg_debugfs:
2049 	iio_device_unregister_debugfs(indio_dev);
2050 	return ret;
2051 }
2052 EXPORT_SYMBOL(__iio_device_register);
2053 
2054 /**
2055  * iio_device_unregister() - unregister a device from the IIO subsystem
2056  * @indio_dev:		Device structure representing the device.
2057  */
2058 void iio_device_unregister(struct iio_dev *indio_dev)
2059 {
2060 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2061 
2062 	cdev_device_del(&iio_dev_opaque->chrdev, &indio_dev->dev);
2063 
2064 	mutex_lock(&iio_dev_opaque->info_exist_lock);
2065 
2066 	iio_device_unregister_debugfs(indio_dev);
2067 
2068 	iio_disable_all_buffers(indio_dev);
2069 
2070 	indio_dev->info = NULL;
2071 
2072 	iio_device_wakeup_eventset(indio_dev);
2073 	iio_buffer_wakeup_poll(indio_dev);
2074 
2075 	mutex_unlock(&iio_dev_opaque->info_exist_lock);
2076 
2077 	iio_buffers_free_sysfs_and_mask(indio_dev);
2078 }
2079 EXPORT_SYMBOL(iio_device_unregister);
2080 
2081 static void devm_iio_device_unreg(void *indio_dev)
2082 {
2083 	iio_device_unregister(indio_dev);
2084 }
2085 
2086 int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
2087 			       struct module *this_mod)
2088 {
2089 	int ret;
2090 
2091 	ret = __iio_device_register(indio_dev, this_mod);
2092 	if (ret)
2093 		return ret;
2094 
2095 	return devm_add_action_or_reset(dev, devm_iio_device_unreg, indio_dev);
2096 }
2097 EXPORT_SYMBOL_GPL(__devm_iio_device_register);
2098 
2099 /**
2100  * iio_device_claim_direct_mode - Keep device in direct mode
2101  * @indio_dev:	the iio_dev associated with the device
2102  *
2103  * If the device is in direct mode it is guaranteed to stay
2104  * that way until iio_device_release_direct_mode() is called.
2105  *
2106  * Use with iio_device_release_direct_mode()
2107  *
2108  * Returns: 0 on success, -EBUSY on failure.
2109  */
2110 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
2111 {
2112 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2113 
2114 	mutex_lock(&iio_dev_opaque->mlock);
2115 
2116 	if (iio_buffer_enabled(indio_dev)) {
2117 		mutex_unlock(&iio_dev_opaque->mlock);
2118 		return -EBUSY;
2119 	}
2120 	return 0;
2121 }
2122 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
2123 
2124 /**
2125  * iio_device_release_direct_mode - releases claim on direct mode
2126  * @indio_dev:	the iio_dev associated with the device
2127  *
2128  * Release the claim. Device is no longer guaranteed to stay
2129  * in direct mode.
2130  *
2131  * Use with iio_device_claim_direct_mode()
2132  */
2133 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
2134 {
2135 	mutex_unlock(&to_iio_dev_opaque(indio_dev)->mlock);
2136 }
2137 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
2138 
2139 /**
2140  * iio_device_claim_buffer_mode - Keep device in buffer mode
2141  * @indio_dev:	the iio_dev associated with the device
2142  *
2143  * If the device is in buffer mode it is guaranteed to stay
2144  * that way until iio_device_release_buffer_mode() is called.
2145  *
2146  * Use with iio_device_release_buffer_mode().
2147  *
2148  * Returns: 0 on success, -EBUSY on failure.
2149  */
2150 int iio_device_claim_buffer_mode(struct iio_dev *indio_dev)
2151 {
2152 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2153 
2154 	mutex_lock(&iio_dev_opaque->mlock);
2155 
2156 	if (iio_buffer_enabled(indio_dev))
2157 		return 0;
2158 
2159 	mutex_unlock(&iio_dev_opaque->mlock);
2160 	return -EBUSY;
2161 }
2162 EXPORT_SYMBOL_GPL(iio_device_claim_buffer_mode);
2163 
2164 /**
2165  * iio_device_release_buffer_mode - releases claim on buffer mode
2166  * @indio_dev:	the iio_dev associated with the device
2167  *
2168  * Release the claim. Device is no longer guaranteed to stay
2169  * in buffer mode.
2170  *
2171  * Use with iio_device_claim_buffer_mode().
2172  */
2173 void iio_device_release_buffer_mode(struct iio_dev *indio_dev)
2174 {
2175 	mutex_unlock(&to_iio_dev_opaque(indio_dev)->mlock);
2176 }
2177 EXPORT_SYMBOL_GPL(iio_device_release_buffer_mode);
2178 
2179 /**
2180  * iio_device_get_current_mode() - helper function providing read-only access to
2181  *				   the opaque @currentmode variable
2182  * @indio_dev:			   IIO device structure for device
2183  */
2184 int iio_device_get_current_mode(struct iio_dev *indio_dev)
2185 {
2186 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2187 
2188 	return iio_dev_opaque->currentmode;
2189 }
2190 EXPORT_SYMBOL_GPL(iio_device_get_current_mode);
2191 
2192 subsys_initcall(iio_init);
2193 module_exit(iio_exit);
2194 
2195 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
2196 MODULE_DESCRIPTION("Industrial I/O core");
2197 MODULE_LICENSE("GPL");
2198