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   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/cleanup.h>
  15#include <linux/debugfs.h>
  16#include <linux/device.h>
  17#include <linux/err.h>
  18#include <linux/fs.h>
  19#include <linux/idr.h>
  20#include <linux/kdev_t.h>
  21#include <linux/kernel.h>
  22#include <linux/module.h>
  23#include <linux/mutex.h>
  24#include <linux/poll.h>
  25#include <linux/property.h>
  26#include <linux/sched.h>
  27#include <linux/slab.h>
  28#include <linux/wait.h>
  29
  30#include <linux/iio/buffer.h>
  31#include <linux/iio/buffer_impl.h>
  32#include <linux/iio/events.h>
  33#include <linux/iio/iio-opaque.h>
  34#include <linux/iio/iio.h>
  35#include <linux/iio/sysfs.h>
  36
  37#include "iio_core.h"
  38#include "iio_core_trigger.h"
  39
  40/* IDA to assign each registered device a unique id */
  41static DEFINE_IDA(iio_ida);
  42
  43static dev_t iio_devt;
  44
  45#define IIO_DEV_MAX 256
  46const struct bus_type iio_bus_type = {
  47	.name = "iio",
  48};
  49EXPORT_SYMBOL(iio_bus_type);
  50
  51static struct dentry *iio_debugfs_dentry;
  52
  53static const char * const iio_direction[] = {
  54	[0] = "in",
  55	[1] = "out",
  56};
  57
  58static const char * const iio_chan_type_name_spec[] = {
  59	[IIO_VOLTAGE] = "voltage",
  60	[IIO_CURRENT] = "current",
  61	[IIO_POWER] = "power",
  62	[IIO_ACCEL] = "accel",
  63	[IIO_ANGL_VEL] = "anglvel",
  64	[IIO_MAGN] = "magn",
  65	[IIO_LIGHT] = "illuminance",
  66	[IIO_INTENSITY] = "intensity",
  67	[IIO_PROXIMITY] = "proximity",
  68	[IIO_TEMP] = "temp",
  69	[IIO_INCLI] = "incli",
  70	[IIO_ROT] = "rot",
  71	[IIO_ANGL] = "angl",
  72	[IIO_TIMESTAMP] = "timestamp",
  73	[IIO_CAPACITANCE] = "capacitance",
  74	[IIO_ALTVOLTAGE] = "altvoltage",
  75	[IIO_CCT] = "cct",
  76	[IIO_PRESSURE] = "pressure",
  77	[IIO_HUMIDITYRELATIVE] = "humidityrelative",
  78	[IIO_ACTIVITY] = "activity",
  79	[IIO_STEPS] = "steps",
  80	[IIO_ENERGY] = "energy",
  81	[IIO_DISTANCE] = "distance",
  82	[IIO_VELOCITY] = "velocity",
  83	[IIO_CONCENTRATION] = "concentration",
  84	[IIO_RESISTANCE] = "resistance",
  85	[IIO_PH] = "ph",
  86	[IIO_UVINDEX] = "uvindex",
  87	[IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
  88	[IIO_COUNT] = "count",
  89	[IIO_INDEX] = "index",
  90	[IIO_GRAVITY]  = "gravity",
  91	[IIO_POSITIONRELATIVE]  = "positionrelative",
  92	[IIO_PHASE] = "phase",
  93	[IIO_MASSCONCENTRATION] = "massconcentration",
  94	[IIO_DELTA_ANGL] = "deltaangl",
  95	[IIO_DELTA_VELOCITY] = "deltavelocity",
  96	[IIO_COLORTEMP] = "colortemp",
  97	[IIO_CHROMATICITY] = "chromaticity",
  98	[IIO_ATTENTION] = "attention",
  99};
 100
 101static const char * const iio_modifier_names[] = {
 102	[IIO_MOD_X] = "x",
 103	[IIO_MOD_Y] = "y",
 104	[IIO_MOD_Z] = "z",
 105	[IIO_MOD_X_AND_Y] = "x&y",
 106	[IIO_MOD_X_AND_Z] = "x&z",
 107	[IIO_MOD_Y_AND_Z] = "y&z",
 108	[IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
 109	[IIO_MOD_X_OR_Y] = "x|y",
 110	[IIO_MOD_X_OR_Z] = "x|z",
 111	[IIO_MOD_Y_OR_Z] = "y|z",
 112	[IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
 113	[IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
 114	[IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
 115	[IIO_MOD_LIGHT_BOTH] = "both",
 116	[IIO_MOD_LIGHT_IR] = "ir",
 117	[IIO_MOD_LIGHT_CLEAR] = "clear",
 118	[IIO_MOD_LIGHT_RED] = "red",
 119	[IIO_MOD_LIGHT_GREEN] = "green",
 120	[IIO_MOD_LIGHT_BLUE] = "blue",
 121	[IIO_MOD_LIGHT_UV] = "uv",
 122	[IIO_MOD_LIGHT_UVA] = "uva",
 123	[IIO_MOD_LIGHT_UVB] = "uvb",
 124	[IIO_MOD_LIGHT_DUV] = "duv",
 125	[IIO_MOD_QUATERNION] = "quaternion",
 126	[IIO_MOD_TEMP_AMBIENT] = "ambient",
 127	[IIO_MOD_TEMP_OBJECT] = "object",
 128	[IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
 129	[IIO_MOD_NORTH_TRUE] = "from_north_true",
 130	[IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
 131	[IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
 132	[IIO_MOD_RUNNING] = "running",
 133	[IIO_MOD_JOGGING] = "jogging",
 134	[IIO_MOD_WALKING] = "walking",
 135	[IIO_MOD_STILL] = "still",
 136	[IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
 137	[IIO_MOD_I] = "i",
 138	[IIO_MOD_Q] = "q",
 139	[IIO_MOD_CO2] = "co2",
 140	[IIO_MOD_VOC] = "voc",
 141	[IIO_MOD_PM1] = "pm1",
 142	[IIO_MOD_PM2P5] = "pm2p5",
 143	[IIO_MOD_PM4] = "pm4",
 144	[IIO_MOD_PM10] = "pm10",
 145	[IIO_MOD_ETHANOL] = "ethanol",
 146	[IIO_MOD_H2] = "h2",
 147	[IIO_MOD_O2] = "o2",
 148	[IIO_MOD_LINEAR_X] = "linear_x",
 149	[IIO_MOD_LINEAR_Y] = "linear_y",
 150	[IIO_MOD_LINEAR_Z] = "linear_z",
 151	[IIO_MOD_PITCH] = "pitch",
 152	[IIO_MOD_YAW] = "yaw",
 153	[IIO_MOD_ROLL] = "roll",
 154};
 155
 156/* relies on pairs of these shared then separate */
 157static const char * const iio_chan_info_postfix[] = {
 158	[IIO_CHAN_INFO_RAW] = "raw",
 159	[IIO_CHAN_INFO_PROCESSED] = "input",
 160	[IIO_CHAN_INFO_SCALE] = "scale",
 161	[IIO_CHAN_INFO_OFFSET] = "offset",
 162	[IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
 163	[IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
 164	[IIO_CHAN_INFO_PEAK] = "peak_raw",
 165	[IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
 166	[IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
 167	[IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
 168	[IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
 169	= "filter_low_pass_3db_frequency",
 170	[IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
 171	= "filter_high_pass_3db_frequency",
 172	[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
 173	[IIO_CHAN_INFO_FREQUENCY] = "frequency",
 174	[IIO_CHAN_INFO_PHASE] = "phase",
 175	[IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 176	[IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
 177	[IIO_CHAN_INFO_HYSTERESIS_RELATIVE] = "hysteresis_relative",
 178	[IIO_CHAN_INFO_INT_TIME] = "integration_time",
 179	[IIO_CHAN_INFO_ENABLE] = "en",
 180	[IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
 181	[IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
 182	[IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
 183	[IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
 184	[IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
 185	[IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
 186	[IIO_CHAN_INFO_THERMOCOUPLE_TYPE] = "thermocouple_type",
 187	[IIO_CHAN_INFO_CALIBAMBIENT] = "calibambient",
 188	[IIO_CHAN_INFO_ZEROPOINT] = "zeropoint",
 189	[IIO_CHAN_INFO_TROUGH] = "trough_raw",
 190};
 191/**
 192 * iio_device_id() - query the unique ID for the device
 193 * @indio_dev:		Device structure whose ID is being queried
 194 *
 195 * The IIO device ID is a unique index used for example for the naming
 196 * of the character device /dev/iio\:device[ID].
 197 *
 198 * Returns: Unique ID for the device.
 199 */
 200int iio_device_id(struct iio_dev *indio_dev)
 201{
 202	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
 203
 204	return iio_dev_opaque->id;
 205}
 206EXPORT_SYMBOL_GPL(iio_device_id);
 207
 208/**
 209 * iio_buffer_enabled() - helper function to test if the buffer is enabled
 210 * @indio_dev:		IIO device structure for device
 211 *
 212 * Returns: True, if the buffer is enabled.
 213 */
 214bool iio_buffer_enabled(struct iio_dev *indio_dev)
 215{
 216	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
 217
 218	return iio_dev_opaque->currentmode & INDIO_ALL_BUFFER_MODES;
 219}
 220EXPORT_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 */
 227struct 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}
 233EXPORT_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 */
 244const 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 */
 256ssize_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}
 262EXPORT_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 */
 271int 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}
 290EXPORT_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 */
 298clockid_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}
 304EXPORT_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 */
 312s64 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}
 336EXPORT_SYMBOL(iio_get_time_ns);
 337
 338static 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
 359error_unregister_bus_type:
 360	bus_unregister(&iio_bus_type);
 361error_nothing:
 362	return ret;
 363}
 364
 365static 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)
 374static 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
 404static 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
 442static 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
 448static 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
 455static 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
 476static void iio_device_register_debugfs(struct iio_dev *indio_dev)
 477{
 478}
 479
 480static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 481{
 482}
 483#endif /* CONFIG_DEBUG_FS */
 484
 485static 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
 498static 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
 512ssize_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}
 533EXPORT_SYMBOL_GPL(iio_enum_available_read);
 534
 535ssize_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}
 552EXPORT_SYMBOL_GPL(iio_enum_read);
 553
 554ssize_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}
 571EXPORT_SYMBOL_GPL(iio_enum_write);
 572
 573static 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
 581static 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
 589ssize_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}
 606EXPORT_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 */
 619int 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}
 639EXPORT_SYMBOL(iio_read_mount_matrix);
 640
 641static 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		tmp0 = (int)div_s64_rem(tmp2, 1000000000, &tmp1);
 672		if ((tmp2 < 0) && (tmp0 == 0))
 673			return sysfs_emit_at(buf, offset, "-0.%09u", abs(tmp1));
 674		else
 675			return sysfs_emit_at(buf, offset, "%d.%09u", tmp0,
 676					     abs(tmp1));
 677	case IIO_VAL_FRACTIONAL_LOG2:
 678		tmp2 = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
 679		tmp0 = (int)div_s64_rem(tmp2, 1000000000LL, &tmp1);
 680		if (tmp0 == 0 && tmp2 < 0)
 681			return sysfs_emit_at(buf, offset, "-0.%09u", abs(tmp1));
 682		else
 683			return sysfs_emit_at(buf, offset, "%d.%09u", tmp0,
 684					     abs(tmp1));
 685	case IIO_VAL_INT_MULTIPLE:
 686	{
 687		int i;
 688		int l = 0;
 689
 690		for (i = 0; i < size; ++i)
 691			l += sysfs_emit_at(buf, offset + l, "%d ", vals[i]);
 692		return l;
 693	}
 694	case IIO_VAL_CHAR:
 695		return sysfs_emit_at(buf, offset, "%c", (char)vals[0]);
 696	case IIO_VAL_INT_64:
 697		tmp2 = (s64)((((u64)vals[1]) << 32) | (u32)vals[0]);
 698		return sysfs_emit_at(buf, offset, "%lld", tmp2);
 699	default:
 700		return 0;
 701	}
 702}
 703
 704/**
 705 * iio_format_value() - Formats a IIO value into its string representation
 706 * @buf:	The buffer to which the formatted value gets written
 707 *		which is assumed to be big enough (i.e. PAGE_SIZE).
 708 * @type:	One of the IIO_VAL_* constants. This decides how the val
 709 *		and val2 parameters are formatted.
 710 * @size:	Number of IIO value entries contained in vals
 711 * @vals:	Pointer to the values, exact meaning depends on the
 712 *		type parameter.
 713 *
 714 * Returns:
 715 * 0 by default, a negative number on failure or the total number of characters
 716 * written for a type that belongs to the IIO_VAL_* constant.
 717 */
 718ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
 719{
 720	ssize_t len;
 721
 722	len = __iio_format_value(buf, 0, type, size, vals);
 723	if (len >= PAGE_SIZE - 1)
 724		return -EFBIG;
 725
 726	return len + sysfs_emit_at(buf, len, "\n");
 727}
 728EXPORT_SYMBOL_GPL(iio_format_value);
 729
 730ssize_t do_iio_read_channel_label(struct iio_dev *indio_dev,
 731				  const struct iio_chan_spec *c,
 732				  char *buf)
 733{
 734	if (indio_dev->info->read_label)
 735		return indio_dev->info->read_label(indio_dev, c, buf);
 736
 737	if (c->extend_name)
 738		return sysfs_emit(buf, "%s\n", c->extend_name);
 739
 740	return -EINVAL;
 741}
 742
 743static ssize_t iio_read_channel_label(struct device *dev,
 744				      struct device_attribute *attr,
 745				      char *buf)
 746{
 747	return do_iio_read_channel_label(dev_to_iio_dev(dev),
 748					 to_iio_dev_attr(attr)->c, buf);
 749}
 750
 751static ssize_t iio_read_channel_info(struct device *dev,
 752				     struct device_attribute *attr,
 753				     char *buf)
 754{
 755	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 756	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 757	int vals[INDIO_MAX_RAW_ELEMENTS];
 758	int ret;
 759	int val_len = 2;
 760
 761	if (indio_dev->info->read_raw_multi)
 762		ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
 763							INDIO_MAX_RAW_ELEMENTS,
 764							vals, &val_len,
 765							this_attr->address);
 766	else if (indio_dev->info->read_raw)
 767		ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 768				    &vals[0], &vals[1], this_attr->address);
 769	else
 770		return -EINVAL;
 771
 772	if (ret < 0)
 773		return ret;
 774
 775	return iio_format_value(buf, ret, val_len, vals);
 776}
 777
 778static ssize_t iio_format_list(char *buf, const int *vals, int type, int length,
 779			       const char *prefix, const char *suffix)
 780{
 781	ssize_t len;
 782	int stride;
 783	int i;
 784
 785	switch (type) {
 786	case IIO_VAL_INT:
 787		stride = 1;
 788		break;
 789	default:
 790		stride = 2;
 791		break;
 792	}
 793
 794	len = sysfs_emit(buf, prefix);
 795
 796	for (i = 0; i <= length - stride; i += stride) {
 797		if (i != 0) {
 798			len += sysfs_emit_at(buf, len, " ");
 799			if (len >= PAGE_SIZE)
 800				return -EFBIG;
 801		}
 802
 803		len += __iio_format_value(buf, len, type, stride, &vals[i]);
 804		if (len >= PAGE_SIZE)
 805			return -EFBIG;
 806	}
 807
 808	len += sysfs_emit_at(buf, len, "%s\n", suffix);
 809
 810	return len;
 811}
 812
 813static ssize_t iio_format_avail_list(char *buf, const int *vals,
 814				     int type, int length)
 815{
 816
 817	return iio_format_list(buf, vals, type, length, "", "");
 818}
 819
 820static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
 821{
 822	int length;
 823
 824	/*
 825	 * length refers to the array size , not the number of elements.
 826	 * The purpose is to print the range [min , step ,max] so length should
 827	 * be 3 in case of int, and 6 for other types.
 828	 */
 829	switch (type) {
 830	case IIO_VAL_INT:
 831		length = 3;
 832		break;
 833	default:
 834		length = 6;
 835		break;
 836	}
 837
 838	return iio_format_list(buf, vals, type, length, "[", "]");
 839}
 840
 841static ssize_t iio_read_channel_info_avail(struct device *dev,
 842					   struct device_attribute *attr,
 843					   char *buf)
 844{
 845	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 846	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 847	const int *vals;
 848	int ret;
 849	int length;
 850	int type;
 851
 852	if (!indio_dev->info->read_avail)
 853		return -EINVAL;
 854
 855	ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
 856					  &vals, &type, &length,
 857					  this_attr->address);
 858
 859	if (ret < 0)
 860		return ret;
 861	switch (ret) {
 862	case IIO_AVAIL_LIST:
 863		return iio_format_avail_list(buf, vals, type, length);
 864	case IIO_AVAIL_RANGE:
 865		return iio_format_avail_range(buf, vals, type);
 866	default:
 867		return -EINVAL;
 868	}
 869}
 870
 871/**
 872 * __iio_str_to_fixpoint() - Parse a fixed-point number from a string
 873 * @str: The string to parse
 874 * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 875 * @integer: The integer part of the number
 876 * @fract: The fractional part of the number
 877 * @scale_db: True if this should parse as dB
 878 *
 879 * Returns:
 880 * 0 on success, or a negative error code if the string could not be parsed.
 881 */
 882static int __iio_str_to_fixpoint(const char *str, int fract_mult,
 883				 int *integer, int *fract, bool scale_db)
 884{
 885	int i = 0, f = 0;
 886	bool integer_part = true, negative = false;
 887
 888	if (fract_mult == 0) {
 889		*fract = 0;
 890
 891		return kstrtoint(str, 0, integer);
 892	}
 893
 894	if (str[0] == '-') {
 895		negative = true;
 896		str++;
 897	} else if (str[0] == '+') {
 898		str++;
 899	}
 900
 901	while (*str) {
 902		if ('0' <= *str && *str <= '9') {
 903			if (integer_part) {
 904				i = i * 10 + *str - '0';
 905			} else {
 906				f += fract_mult * (*str - '0');
 907				fract_mult /= 10;
 908			}
 909		} else if (*str == '\n') {
 910			if (*(str + 1) == '\0')
 911				break;
 912			return -EINVAL;
 913		} else if (!strncmp(str, " dB", sizeof(" dB") - 1) && scale_db) {
 914			/* Ignore the dB suffix */
 915			str += sizeof(" dB") - 1;
 916			continue;
 917		} else if (!strncmp(str, "dB", sizeof("dB") - 1) && scale_db) {
 918			/* Ignore the dB suffix */
 919			str += sizeof("dB") - 1;
 920			continue;
 921		} else if (*str == '.' && integer_part) {
 922			integer_part = false;
 923		} else {
 924			return -EINVAL;
 925		}
 926		str++;
 927	}
 928
 929	if (negative) {
 930		if (i)
 931			i = -i;
 932		else
 933			f = -f;
 934	}
 935
 936	*integer = i;
 937	*fract = f;
 938
 939	return 0;
 940}
 941
 942/**
 943 * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 944 * @str: The string to parse
 945 * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 946 * @integer: The integer part of the number
 947 * @fract: The fractional part of the number
 948 *
 949 * Returns:
 950 * 0 on success, or a negative error code if the string could not be parsed.
 951 */
 952int iio_str_to_fixpoint(const char *str, int fract_mult,
 953			int *integer, int *fract)
 954{
 955	return __iio_str_to_fixpoint(str, fract_mult, integer, fract, false);
 956}
 957EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 958
 959static ssize_t iio_write_channel_info(struct device *dev,
 960				      struct device_attribute *attr,
 961				      const char *buf,
 962				      size_t len)
 963{
 964	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 965	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 966	int ret, fract_mult = 100000;
 967	int integer, fract = 0;
 968	bool is_char = false;
 969	bool scale_db = false;
 970
 971	/* Assumes decimal - precision based on number of digits */
 972	if (!indio_dev->info->write_raw)
 973		return -EINVAL;
 974
 975	if (indio_dev->info->write_raw_get_fmt)
 976		switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 977			this_attr->c, this_attr->address)) {
 978		case IIO_VAL_INT:
 979			fract_mult = 0;
 980			break;
 981		case IIO_VAL_INT_PLUS_MICRO_DB:
 982			scale_db = true;
 983			fallthrough;
 984		case IIO_VAL_INT_PLUS_MICRO:
 985			fract_mult = 100000;
 986			break;
 987		case IIO_VAL_INT_PLUS_NANO:
 988			fract_mult = 100000000;
 989			break;
 990		case IIO_VAL_CHAR:
 991			is_char = true;
 992			break;
 993		default:
 994			return -EINVAL;
 995		}
 996
 997	if (is_char) {
 998		char ch;
 999
1000		if (sscanf(buf, "%c", &ch) != 1)
1001			return -EINVAL;
1002		integer = ch;
1003	} else {
1004		ret = __iio_str_to_fixpoint(buf, fract_mult, &integer, &fract,
1005					    scale_db);
1006		if (ret)
1007			return ret;
1008	}
1009
1010	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
1011					 integer, fract, this_attr->address);
1012	if (ret)
1013		return ret;
1014
1015	return len;
1016}
1017
1018static
1019int __iio_device_attr_init(struct device_attribute *dev_attr,
1020			   const char *postfix,
1021			   struct iio_chan_spec const *chan,
1022			   ssize_t (*readfunc)(struct device *dev,
1023					       struct device_attribute *attr,
1024					       char *buf),
1025			   ssize_t (*writefunc)(struct device *dev,
1026						struct device_attribute *attr,
1027						const char *buf,
1028						size_t len),
1029			   enum iio_shared_by shared_by)
1030{
1031	int ret = 0;
1032	char *name = NULL;
1033	char *full_postfix;
1034
1035	sysfs_attr_init(&dev_attr->attr);
1036
1037	/* Build up postfix of <extend_name>_<modifier>_postfix */
1038	if (chan->modified && (shared_by == IIO_SEPARATE)) {
1039		if (chan->extend_name)
1040			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
1041						 iio_modifier_names[chan->channel2],
1042						 chan->extend_name,
1043						 postfix);
1044		else
1045			full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
1046						 iio_modifier_names[chan->channel2],
1047						 postfix);
1048	} else {
1049		if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
1050			full_postfix = kstrdup(postfix, GFP_KERNEL);
1051		else
1052			full_postfix = kasprintf(GFP_KERNEL,
1053						 "%s_%s",
1054						 chan->extend_name,
1055						 postfix);
1056	}
1057	if (full_postfix == NULL)
1058		return -ENOMEM;
1059
1060	if (chan->differential) { /* Differential can not have modifier */
1061		switch (shared_by) {
1062		case IIO_SHARED_BY_ALL:
1063			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
1064			break;
1065		case IIO_SHARED_BY_DIR:
1066			name = kasprintf(GFP_KERNEL, "%s_%s",
1067						iio_direction[chan->output],
1068						full_postfix);
1069			break;
1070		case IIO_SHARED_BY_TYPE:
1071			name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
1072					    iio_direction[chan->output],
1073					    iio_chan_type_name_spec[chan->type],
1074					    iio_chan_type_name_spec[chan->type],
1075					    full_postfix);
1076			break;
1077		case IIO_SEPARATE:
1078			if (!chan->indexed) {
1079				WARN(1, "Differential channels must be indexed\n");
1080				ret = -EINVAL;
1081				goto error_free_full_postfix;
1082			}
1083			name = kasprintf(GFP_KERNEL,
1084					    "%s_%s%d-%s%d_%s",
1085					    iio_direction[chan->output],
1086					    iio_chan_type_name_spec[chan->type],
1087					    chan->channel,
1088					    iio_chan_type_name_spec[chan->type],
1089					    chan->channel2,
1090					    full_postfix);
1091			break;
1092		}
1093	} else { /* Single ended */
1094		switch (shared_by) {
1095		case IIO_SHARED_BY_ALL:
1096			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
1097			break;
1098		case IIO_SHARED_BY_DIR:
1099			name = kasprintf(GFP_KERNEL, "%s_%s",
1100						iio_direction[chan->output],
1101						full_postfix);
1102			break;
1103		case IIO_SHARED_BY_TYPE:
1104			name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1105					    iio_direction[chan->output],
1106					    iio_chan_type_name_spec[chan->type],
1107					    full_postfix);
1108			break;
1109
1110		case IIO_SEPARATE:
1111			if (chan->indexed)
1112				name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
1113						    iio_direction[chan->output],
1114						    iio_chan_type_name_spec[chan->type],
1115						    chan->channel,
1116						    full_postfix);
1117			else
1118				name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1119						    iio_direction[chan->output],
1120						    iio_chan_type_name_spec[chan->type],
1121						    full_postfix);
1122			break;
1123		}
1124	}
1125	if (name == NULL) {
1126		ret = -ENOMEM;
1127		goto error_free_full_postfix;
1128	}
1129	dev_attr->attr.name = name;
1130
1131	if (readfunc) {
1132		dev_attr->attr.mode |= 0444;
1133		dev_attr->show = readfunc;
1134	}
1135
1136	if (writefunc) {
1137		dev_attr->attr.mode |= 0200;
1138		dev_attr->store = writefunc;
1139	}
1140
1141error_free_full_postfix:
1142	kfree(full_postfix);
1143
1144	return ret;
1145}
1146
1147static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1148{
1149	kfree(dev_attr->attr.name);
1150}
1151
1152int __iio_add_chan_devattr(const char *postfix,
1153			   struct iio_chan_spec const *chan,
1154			   ssize_t (*readfunc)(struct device *dev,
1155					       struct device_attribute *attr,
1156					       char *buf),
1157			   ssize_t (*writefunc)(struct device *dev,
1158						struct device_attribute *attr,
1159						const char *buf,
1160						size_t len),
1161			   u64 mask,
1162			   enum iio_shared_by shared_by,
1163			   struct device *dev,
1164			   struct iio_buffer *buffer,
1165			   struct list_head *attr_list)
1166{
1167	int ret;
1168	struct iio_dev_attr *iio_attr, *t;
1169
1170	iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1171	if (iio_attr == NULL)
1172		return -ENOMEM;
1173	ret = __iio_device_attr_init(&iio_attr->dev_attr,
1174				     postfix, chan,
1175				     readfunc, writefunc, shared_by);
1176	if (ret)
1177		goto error_iio_dev_attr_free;
1178	iio_attr->c = chan;
1179	iio_attr->address = mask;
1180	iio_attr->buffer = buffer;
1181	list_for_each_entry(t, attr_list, l)
1182		if (strcmp(t->dev_attr.attr.name,
1183			   iio_attr->dev_attr.attr.name) == 0) {
1184			if (shared_by == IIO_SEPARATE)
1185				dev_err(dev, "tried to double register : %s\n",
1186					t->dev_attr.attr.name);
1187			ret = -EBUSY;
1188			goto error_device_attr_deinit;
1189		}
1190	list_add(&iio_attr->l, attr_list);
1191
1192	return 0;
1193
1194error_device_attr_deinit:
1195	__iio_device_attr_deinit(&iio_attr->dev_attr);
1196error_iio_dev_attr_free:
1197	kfree(iio_attr);
1198	return ret;
1199}
1200
1201static int iio_device_add_channel_label(struct iio_dev *indio_dev,
1202					 struct iio_chan_spec const *chan)
1203{
1204	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1205	int ret;
1206
1207	if (!indio_dev->info->read_label && !chan->extend_name)
1208		return 0;
1209
1210	ret = __iio_add_chan_devattr("label",
1211				     chan,
1212				     &iio_read_channel_label,
1213				     NULL,
1214				     0,
1215				     IIO_SEPARATE,
1216				     &indio_dev->dev,
1217				     NULL,
1218				     &iio_dev_opaque->channel_attr_list);
1219	if (ret < 0)
1220		return ret;
1221
1222	return 1;
1223}
1224
1225static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1226					 struct iio_chan_spec const *chan,
1227					 enum iio_shared_by shared_by,
1228					 const long *infomask)
1229{
1230	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1231	int i, ret, attrcount = 0;
1232
1233	for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1234		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1235			return -EINVAL;
1236		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1237					     chan,
1238					     &iio_read_channel_info,
1239					     &iio_write_channel_info,
1240					     i,
1241					     shared_by,
1242					     &indio_dev->dev,
1243					     NULL,
1244					     &iio_dev_opaque->channel_attr_list);
1245		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1246			continue;
1247		if (ret < 0)
1248			return ret;
1249		attrcount++;
1250	}
1251
1252	return attrcount;
1253}
1254
1255static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1256					       struct iio_chan_spec const *chan,
1257					       enum iio_shared_by shared_by,
1258					       const long *infomask)
1259{
1260	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1261	int i, ret, attrcount = 0;
1262	char *avail_postfix;
1263
1264	for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1265		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1266			return -EINVAL;
1267		avail_postfix = kasprintf(GFP_KERNEL,
1268					  "%s_available",
1269					  iio_chan_info_postfix[i]);
1270		if (!avail_postfix)
1271			return -ENOMEM;
1272
1273		ret = __iio_add_chan_devattr(avail_postfix,
1274					     chan,
1275					     &iio_read_channel_info_avail,
1276					     NULL,
1277					     i,
1278					     shared_by,
1279					     &indio_dev->dev,
1280					     NULL,
1281					     &iio_dev_opaque->channel_attr_list);
1282		kfree(avail_postfix);
1283		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1284			continue;
1285		if (ret < 0)
1286			return ret;
1287		attrcount++;
1288	}
1289
1290	return attrcount;
1291}
1292
1293static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1294					struct iio_chan_spec const *chan)
1295{
1296	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1297	int ret, attrcount = 0;
1298	const struct iio_chan_spec_ext_info *ext_info;
1299
1300	if (chan->channel < 0)
1301		return 0;
1302	ret = iio_device_add_info_mask_type(indio_dev, chan,
1303					    IIO_SEPARATE,
1304					    &chan->info_mask_separate);
1305	if (ret < 0)
1306		return ret;
1307	attrcount += ret;
1308
1309	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1310						  IIO_SEPARATE,
1311						  &chan->info_mask_separate_available);
1312	if (ret < 0)
1313		return ret;
1314	attrcount += ret;
1315
1316	ret = iio_device_add_info_mask_type(indio_dev, chan,
1317					    IIO_SHARED_BY_TYPE,
1318					    &chan->info_mask_shared_by_type);
1319	if (ret < 0)
1320		return ret;
1321	attrcount += ret;
1322
1323	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1324						  IIO_SHARED_BY_TYPE,
1325						  &chan->info_mask_shared_by_type_available);
1326	if (ret < 0)
1327		return ret;
1328	attrcount += ret;
1329
1330	ret = iio_device_add_info_mask_type(indio_dev, chan,
1331					    IIO_SHARED_BY_DIR,
1332					    &chan->info_mask_shared_by_dir);
1333	if (ret < 0)
1334		return ret;
1335	attrcount += ret;
1336
1337	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1338						  IIO_SHARED_BY_DIR,
1339						  &chan->info_mask_shared_by_dir_available);
1340	if (ret < 0)
1341		return ret;
1342	attrcount += ret;
1343
1344	ret = iio_device_add_info_mask_type(indio_dev, chan,
1345					    IIO_SHARED_BY_ALL,
1346					    &chan->info_mask_shared_by_all);
1347	if (ret < 0)
1348		return ret;
1349	attrcount += ret;
1350
1351	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1352						  IIO_SHARED_BY_ALL,
1353						  &chan->info_mask_shared_by_all_available);
1354	if (ret < 0)
1355		return ret;
1356	attrcount += ret;
1357
1358	ret = iio_device_add_channel_label(indio_dev, chan);
1359	if (ret < 0)
1360		return ret;
1361	attrcount += ret;
1362
1363	if (chan->ext_info) {
1364		unsigned int i = 0;
1365
1366		for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1367			ret = __iio_add_chan_devattr(ext_info->name,
1368					chan,
1369					ext_info->read ?
1370					    &iio_read_channel_ext_info : NULL,
1371					ext_info->write ?
1372					    &iio_write_channel_ext_info : NULL,
1373					i,
1374					ext_info->shared,
1375					&indio_dev->dev,
1376					NULL,
1377					&iio_dev_opaque->channel_attr_list);
1378			i++;
1379			if (ret == -EBUSY && ext_info->shared)
1380				continue;
1381
1382			if (ret)
1383				return ret;
1384
1385			attrcount++;
1386		}
1387	}
1388
1389	return attrcount;
1390}
1391
1392/**
1393 * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1394 * @attr_list: List of IIO device attributes
1395 *
1396 * This function frees the memory allocated for each of the IIO device
1397 * attributes in the list.
1398 */
1399void iio_free_chan_devattr_list(struct list_head *attr_list)
1400{
1401	struct iio_dev_attr *p, *n;
1402
1403	list_for_each_entry_safe(p, n, attr_list, l) {
1404		kfree_const(p->dev_attr.attr.name);
1405		list_del(&p->l);
1406		kfree(p);
1407	}
1408}
1409
1410static ssize_t name_show(struct device *dev, struct device_attribute *attr,
1411			 char *buf)
1412{
1413	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1414
1415	return sysfs_emit(buf, "%s\n", indio_dev->name);
1416}
1417
1418static DEVICE_ATTR_RO(name);
1419
1420static ssize_t label_show(struct device *dev, struct device_attribute *attr,
1421			  char *buf)
1422{
1423	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1424
1425	return sysfs_emit(buf, "%s\n", indio_dev->label);
1426}
1427
1428static DEVICE_ATTR_RO(label);
1429
1430static const char * const clock_names[] = {
1431	[CLOCK_REALTIME]	 	= "realtime",
1432	[CLOCK_MONOTONIC]	 	= "monotonic",
1433	[CLOCK_PROCESS_CPUTIME_ID]	= "process_cputime_id",
1434	[CLOCK_THREAD_CPUTIME_ID]	= "thread_cputime_id",
1435	[CLOCK_MONOTONIC_RAW]	 	= "monotonic_raw",
1436	[CLOCK_REALTIME_COARSE]	 	= "realtime_coarse",
1437	[CLOCK_MONOTONIC_COARSE] 	= "monotonic_coarse",
1438	[CLOCK_BOOTTIME]	 	= "boottime",
1439	[CLOCK_REALTIME_ALARM]		= "realtime_alarm",
1440	[CLOCK_BOOTTIME_ALARM]		= "boottime_alarm",
1441	[CLOCK_SGI_CYCLE]		= "sgi_cycle",
1442	[CLOCK_TAI]		 	= "tai",
1443};
1444
1445static ssize_t current_timestamp_clock_show(struct device *dev,
1446					    struct device_attribute *attr,
1447					    char *buf)
1448{
1449	const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1450	const clockid_t clk = iio_device_get_clock(indio_dev);
1451
1452	switch (clk) {
1453	case CLOCK_REALTIME:
1454	case CLOCK_MONOTONIC:
1455	case CLOCK_MONOTONIC_RAW:
1456	case CLOCK_REALTIME_COARSE:
1457	case CLOCK_MONOTONIC_COARSE:
1458	case CLOCK_BOOTTIME:
1459	case CLOCK_TAI:
1460		break;
1461	default:
1462		BUG();
1463	}
1464
1465	return sysfs_emit(buf, "%s\n", clock_names[clk]);
1466}
1467
1468static ssize_t current_timestamp_clock_store(struct device *dev,
1469					     struct device_attribute *attr,
1470					     const char *buf, size_t len)
1471{
1472	clockid_t clk;
1473	int ret;
1474
1475	ret = sysfs_match_string(clock_names, buf);
1476	if (ret < 0)
1477		return ret;
1478	clk = ret;
1479
1480	switch (clk) {
1481	case CLOCK_REALTIME:
1482	case CLOCK_MONOTONIC:
1483	case CLOCK_MONOTONIC_RAW:
1484	case CLOCK_REALTIME_COARSE:
1485	case CLOCK_MONOTONIC_COARSE:
1486	case CLOCK_BOOTTIME:
1487	case CLOCK_TAI:
1488		break;
1489	default:
1490		return -EINVAL;
1491	}
1492
1493	ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1494	if (ret)
1495		return ret;
1496
1497	return len;
1498}
1499
1500int iio_device_register_sysfs_group(struct iio_dev *indio_dev,
1501				    const struct attribute_group *group)
1502{
1503	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1504	const struct attribute_group **new, **old = iio_dev_opaque->groups;
1505	unsigned int cnt = iio_dev_opaque->groupcounter;
1506
1507	new = krealloc_array(old, cnt + 2, sizeof(*new), GFP_KERNEL);
1508	if (!new)
1509		return -ENOMEM;
1510
1511	new[iio_dev_opaque->groupcounter++] = group;
1512	new[iio_dev_opaque->groupcounter] = NULL;
1513
1514	iio_dev_opaque->groups = new;
1515
1516	return 0;
1517}
1518
1519static DEVICE_ATTR_RW(current_timestamp_clock);
1520
1521static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1522{
1523	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1524	int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1525	struct iio_dev_attr *p;
1526	struct attribute **attr, *clk = NULL;
1527
1528	/* First count elements in any existing group */
1529	if (indio_dev->info->attrs) {
1530		attr = indio_dev->info->attrs->attrs;
1531		while (*attr++ != NULL)
1532			attrcount_orig++;
1533	}
1534	attrcount = attrcount_orig;
1535	/*
1536	 * New channel registration method - relies on the fact a group does
1537	 * not need to be initialized if its name is NULL.
1538	 */
1539	if (indio_dev->channels)
1540		for (i = 0; i < indio_dev->num_channels; i++) {
1541			const struct iio_chan_spec *chan =
1542				&indio_dev->channels[i];
1543
1544			if (chan->type == IIO_TIMESTAMP)
1545				clk = &dev_attr_current_timestamp_clock.attr;
1546
1547			ret = iio_device_add_channel_sysfs(indio_dev, chan);
1548			if (ret < 0)
1549				goto error_clear_attrs;
1550			attrcount += ret;
1551		}
1552
1553	if (iio_dev_opaque->event_interface)
1554		clk = &dev_attr_current_timestamp_clock.attr;
1555
1556	if (indio_dev->name)
1557		attrcount++;
1558	if (indio_dev->label)
1559		attrcount++;
1560	if (clk)
1561		attrcount++;
1562
1563	iio_dev_opaque->chan_attr_group.attrs =
1564		kcalloc(attrcount + 1,
1565			sizeof(iio_dev_opaque->chan_attr_group.attrs[0]),
1566			GFP_KERNEL);
1567	if (iio_dev_opaque->chan_attr_group.attrs == NULL) {
1568		ret = -ENOMEM;
1569		goto error_clear_attrs;
1570	}
1571	/* Copy across original attributes, and point to original binary attributes */
1572	if (indio_dev->info->attrs) {
1573		memcpy(iio_dev_opaque->chan_attr_group.attrs,
1574		       indio_dev->info->attrs->attrs,
1575		       sizeof(iio_dev_opaque->chan_attr_group.attrs[0])
1576		       *attrcount_orig);
1577		iio_dev_opaque->chan_attr_group.is_visible =
1578			indio_dev->info->attrs->is_visible;
1579		iio_dev_opaque->chan_attr_group.bin_attrs =
1580			indio_dev->info->attrs->bin_attrs;
1581	}
1582	attrn = attrcount_orig;
1583	/* Add all elements from the list. */
1584	list_for_each_entry(p, &iio_dev_opaque->channel_attr_list, l)
1585		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1586	if (indio_dev->name)
1587		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1588	if (indio_dev->label)
1589		iio_dev_opaque->chan_attr_group.attrs[attrn++] = &dev_attr_label.attr;
1590	if (clk)
1591		iio_dev_opaque->chan_attr_group.attrs[attrn++] = clk;
1592
1593	ret = iio_device_register_sysfs_group(indio_dev,
1594					      &iio_dev_opaque->chan_attr_group);
1595	if (ret)
1596		goto error_free_chan_attrs;
1597
1598	return 0;
1599
1600error_free_chan_attrs:
1601	kfree(iio_dev_opaque->chan_attr_group.attrs);
1602	iio_dev_opaque->chan_attr_group.attrs = NULL;
1603error_clear_attrs:
1604	iio_free_chan_devattr_list(&iio_dev_opaque->channel_attr_list);
1605
1606	return ret;
1607}
1608
1609static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1610{
1611	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1612
1613	iio_free_chan_devattr_list(&iio_dev_opaque->channel_attr_list);
1614	kfree(iio_dev_opaque->chan_attr_group.attrs);
1615	iio_dev_opaque->chan_attr_group.attrs = NULL;
1616	kfree(iio_dev_opaque->groups);
1617	iio_dev_opaque->groups = NULL;
1618}
1619
1620static void iio_dev_release(struct device *device)
1621{
1622	struct iio_dev *indio_dev = dev_to_iio_dev(device);
1623	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1624
1625	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1626		iio_device_unregister_trigger_consumer(indio_dev);
1627	iio_device_unregister_eventset(indio_dev);
1628	iio_device_unregister_sysfs(indio_dev);
1629
1630	iio_device_detach_buffers(indio_dev);
1631
1632	lockdep_unregister_key(&iio_dev_opaque->mlock_key);
1633
1634	ida_free(&iio_ida, iio_dev_opaque->id);
1635	kfree(iio_dev_opaque);
1636}
1637
1638const struct device_type iio_device_type = {
1639	.name = "iio_device",
1640	.release = iio_dev_release,
1641};
1642
1643/**
1644 * iio_device_alloc() - allocate an iio_dev from a driver
1645 * @parent:		Parent device.
1646 * @sizeof_priv:	Space to allocate for private structure.
1647 *
1648 * Returns:
1649 * Pointer to allocated iio_dev on success, NULL on failure.
1650 */
1651struct iio_dev *iio_device_alloc(struct device *parent, int sizeof_priv)
1652{
1653	struct iio_dev_opaque *iio_dev_opaque;
1654	struct iio_dev *indio_dev;
1655	size_t alloc_size;
1656
1657	if (sizeof_priv)
1658		alloc_size = ALIGN(sizeof(*iio_dev_opaque), IIO_DMA_MINALIGN) + sizeof_priv;
1659	else
1660		alloc_size = sizeof(*iio_dev_opaque);
1661
1662	iio_dev_opaque = kzalloc(alloc_size, GFP_KERNEL);
1663	if (!iio_dev_opaque)
1664		return NULL;
1665
1666	indio_dev = &iio_dev_opaque->indio_dev;
1667
1668	if (sizeof_priv)
1669		ACCESS_PRIVATE(indio_dev, priv) = (char *)iio_dev_opaque +
1670			ALIGN(sizeof(*iio_dev_opaque), IIO_DMA_MINALIGN);
1671
1672	indio_dev->dev.parent = parent;
1673	indio_dev->dev.type = &iio_device_type;
1674	indio_dev->dev.bus = &iio_bus_type;
1675	device_initialize(&indio_dev->dev);
1676	mutex_init(&iio_dev_opaque->mlock);
1677	mutex_init(&iio_dev_opaque->info_exist_lock);
1678	INIT_LIST_HEAD(&iio_dev_opaque->channel_attr_list);
1679
1680	iio_dev_opaque->id = ida_alloc(&iio_ida, GFP_KERNEL);
1681	if (iio_dev_opaque->id < 0) {
1682		/* cannot use a dev_err as the name isn't available */
1683		pr_err("failed to get device id\n");
1684		kfree(iio_dev_opaque);
1685		return NULL;
1686	}
1687
1688	if (dev_set_name(&indio_dev->dev, "iio:device%d", iio_dev_opaque->id)) {
1689		ida_free(&iio_ida, iio_dev_opaque->id);
1690		kfree(iio_dev_opaque);
1691		return NULL;
1692	}
1693
1694	INIT_LIST_HEAD(&iio_dev_opaque->buffer_list);
1695	INIT_LIST_HEAD(&iio_dev_opaque->ioctl_handlers);
1696
1697	lockdep_register_key(&iio_dev_opaque->mlock_key);
1698	lockdep_set_class(&iio_dev_opaque->mlock, &iio_dev_opaque->mlock_key);
1699
1700	return indio_dev;
1701}
1702EXPORT_SYMBOL(iio_device_alloc);
1703
1704/**
1705 * iio_device_free() - free an iio_dev from a driver
1706 * @dev:		the iio_dev associated with the device
1707 */
1708void iio_device_free(struct iio_dev *dev)
1709{
1710	if (dev)
1711		put_device(&dev->dev);
1712}
1713EXPORT_SYMBOL(iio_device_free);
1714
1715static void devm_iio_device_release(void *iio_dev)
1716{
1717	iio_device_free(iio_dev);
1718}
1719
1720/**
1721 * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1722 * @parent:		Device to allocate iio_dev for, and parent for this IIO device
1723 * @sizeof_priv:	Space to allocate for private structure.
1724 *
1725 * Managed iio_device_alloc. iio_dev allocated with this function is
1726 * automatically freed on driver detach.
1727 *
1728 * Returns:
1729 * Pointer to allocated iio_dev on success, NULL on failure.
1730 */
1731struct iio_dev *devm_iio_device_alloc(struct device *parent, int sizeof_priv)
1732{
1733	struct iio_dev *iio_dev;
1734	int ret;
1735
1736	iio_dev = iio_device_alloc(parent, sizeof_priv);
1737	if (!iio_dev)
1738		return NULL;
1739
1740	ret = devm_add_action_or_reset(parent, devm_iio_device_release,
1741				       iio_dev);
1742	if (ret)
1743		return NULL;
1744
1745	return iio_dev;
1746}
1747EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1748
1749/**
1750 * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1751 * @inode:	Inode structure for identifying the device in the file system
1752 * @filp:	File structure for iio device used to keep and later access
1753 *		private data
1754 *
1755 * Returns: 0 on success or -EBUSY if the device is already opened
1756 */
1757static int iio_chrdev_open(struct inode *inode, struct file *filp)
1758{
1759	struct iio_dev_opaque *iio_dev_opaque =
1760		container_of(inode->i_cdev, struct iio_dev_opaque, chrdev);
1761	struct iio_dev *indio_dev = &iio_dev_opaque->indio_dev;
1762	struct iio_dev_buffer_pair *ib;
1763
1764	if (test_and_set_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags))
1765		return -EBUSY;
1766
1767	iio_device_get(indio_dev);
1768
1769	ib = kmalloc(sizeof(*ib), GFP_KERNEL);
1770	if (!ib) {
1771		iio_device_put(indio_dev);
1772		clear_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags);
1773		return -ENOMEM;
1774	}
1775
1776	ib->indio_dev = indio_dev;
1777	ib->buffer = indio_dev->buffer;
1778
1779	filp->private_data = ib;
1780
1781	return 0;
1782}
1783
1784/**
1785 * iio_chrdev_release() - chrdev file close buffer access and ioctls
1786 * @inode:	Inode structure pointer for the char device
1787 * @filp:	File structure pointer for the char device
1788 *
1789 * Returns: 0 for successful release.
1790 */
1791static int iio_chrdev_release(struct inode *inode, struct file *filp)
1792{
1793	struct iio_dev_buffer_pair *ib = filp->private_data;
1794	struct iio_dev_opaque *iio_dev_opaque =
1795		container_of(inode->i_cdev, struct iio_dev_opaque, chrdev);
1796	struct iio_dev *indio_dev = &iio_dev_opaque->indio_dev;
1797
1798	kfree(ib);
1799	clear_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags);
1800	iio_device_put(indio_dev);
1801
1802	return 0;
1803}
1804
1805void iio_device_ioctl_handler_register(struct iio_dev *indio_dev,
1806				       struct iio_ioctl_handler *h)
1807{
1808	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1809
1810	list_add_tail(&h->entry, &iio_dev_opaque->ioctl_handlers);
1811}
1812
1813void iio_device_ioctl_handler_unregister(struct iio_ioctl_handler *h)
1814{
1815	list_del(&h->entry);
1816}
1817
1818static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1819{
1820	struct iio_dev_buffer_pair *ib = filp->private_data;
1821	struct iio_dev *indio_dev = ib->indio_dev;
1822	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1823	struct iio_ioctl_handler *h;
1824	int ret;
1825
1826	guard(mutex)(&iio_dev_opaque->info_exist_lock);
1827	/*
1828	 * The NULL check here is required to prevent crashing when a device
1829	 * is being removed while userspace would still have open file handles
1830	 * to try to access this device.
1831	 */
1832	if (!indio_dev->info)
1833		return -ENODEV;
1834
1835	list_for_each_entry(h, &iio_dev_opaque->ioctl_handlers, entry) {
1836		ret = h->ioctl(indio_dev, filp, cmd, arg);
1837		if (ret != IIO_IOCTL_UNHANDLED)
1838			return ret;
1839	}
1840
1841	return -ENODEV;
1842}
1843
1844static const struct file_operations iio_buffer_fileops = {
1845	.owner = THIS_MODULE,
1846	.llseek = noop_llseek,
1847	.read = iio_buffer_read_outer_addr,
1848	.write = iio_buffer_write_outer_addr,
1849	.poll = iio_buffer_poll_addr,
1850	.unlocked_ioctl = iio_ioctl,
1851	.compat_ioctl = compat_ptr_ioctl,
1852	.open = iio_chrdev_open,
1853	.release = iio_chrdev_release,
1854};
1855
1856static const struct file_operations iio_event_fileops = {
1857	.owner = THIS_MODULE,
1858	.llseek = noop_llseek,
1859	.unlocked_ioctl = iio_ioctl,
1860	.compat_ioctl = compat_ptr_ioctl,
1861	.open = iio_chrdev_open,
1862	.release = iio_chrdev_release,
1863};
1864
1865static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1866{
1867	int i, j;
1868	const struct iio_chan_spec *channels = indio_dev->channels;
1869
1870	if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1871		return 0;
1872
1873	for (i = 0; i < indio_dev->num_channels - 1; i++) {
1874		if (channels[i].scan_index < 0)
1875			continue;
1876		for (j = i + 1; j < indio_dev->num_channels; j++)
1877			if (channels[i].scan_index == channels[j].scan_index) {
1878				dev_err(&indio_dev->dev,
1879					"Duplicate scan index %d\n",
1880					channels[i].scan_index);
1881				return -EINVAL;
1882			}
1883	}
1884
1885	return 0;
1886}
1887
1888static int iio_check_extended_name(const struct iio_dev *indio_dev)
1889{
1890	unsigned int i;
1891
1892	if (!indio_dev->info->read_label)
1893		return 0;
1894
1895	for (i = 0; i < indio_dev->num_channels; i++) {
1896		if (indio_dev->channels[i].extend_name) {
1897			dev_err(&indio_dev->dev,
1898				"Cannot use labels and extend_name at the same time\n");
1899			return -EINVAL;
1900		}
1901	}
1902
1903	return 0;
1904}
1905
1906static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1907
1908static void iio_sanity_check_avail_scan_masks(struct iio_dev *indio_dev)
1909{
1910	unsigned int num_masks, masklength, longs_per_mask;
1911	const unsigned long *av_masks;
1912	int i;
1913
1914	av_masks = indio_dev->available_scan_masks;
1915	masklength = iio_get_masklength(indio_dev);
1916	longs_per_mask = BITS_TO_LONGS(masklength);
1917
1918	/*
1919	 * The code determining how many available_scan_masks is in the array
1920	 * will be assuming the end of masks when first long with all bits
1921	 * zeroed is encountered. This is incorrect for masks where mask
1922	 * consists of more than one long, and where some of the available masks
1923	 * has long worth of bits zeroed (but has subsequent bit(s) set). This
1924	 * is a safety measure against bug where array of masks is terminated by
1925	 * a single zero while mask width is greater than width of a long.
1926	 */
1927	if (longs_per_mask > 1)
1928		dev_warn(indio_dev->dev.parent,
1929			 "multi long available scan masks not fully supported\n");
1930
1931	if (bitmap_empty(av_masks, masklength))
1932		dev_warn(indio_dev->dev.parent, "empty scan mask\n");
1933
1934	for (num_masks = 0; *av_masks; num_masks++)
1935		av_masks += longs_per_mask;
1936
1937	if (num_masks < 2)
1938		return;
1939
1940	av_masks = indio_dev->available_scan_masks;
1941
1942	/*
1943	 * Go through all the masks from first to one before the last, and see
1944	 * that no mask found later from the available_scan_masks array is a
1945	 * subset of mask found earlier. If this happens, then the mask found
1946	 * later will never get used because scanning the array is stopped when
1947	 * the first suitable mask is found. Drivers should order the array of
1948	 * available masks in the order of preference (presumably the least
1949	 * costy to access masks first).
1950	 */
1951	for (i = 0; i < num_masks - 1; i++) {
1952		const unsigned long *mask1;
1953		int j;
1954
1955		mask1 = av_masks + i * longs_per_mask;
1956		for (j = i + 1; j < num_masks; j++) {
1957			const unsigned long *mask2;
1958
1959			mask2 = av_masks + j * longs_per_mask;
1960			if (bitmap_subset(mask2, mask1, masklength))
1961				dev_warn(indio_dev->dev.parent,
1962					 "available_scan_mask %d subset of %d. Never used\n",
1963					 j, i);
1964		}
1965	}
1966}
1967
1968/**
1969 * iio_active_scan_mask_index - Get index of the active scan mask inside the
1970 * available scan masks array
1971 * @indio_dev: the IIO device containing the active and available scan masks
1972 *
1973 * Returns: the index or -EINVAL if  active_scan_mask is not set
1974 */
1975int iio_active_scan_mask_index(struct iio_dev *indio_dev)
1976
1977{
1978	const unsigned long *av_masks;
1979	unsigned int masklength = iio_get_masklength(indio_dev);
1980	int i = 0;
1981
1982	if (!indio_dev->active_scan_mask)
1983		return -EINVAL;
1984
1985	/*
1986	 * As in iio_scan_mask_match and iio_sanity_check_avail_scan_masks,
1987	 * the condition here do not handle multi-long masks correctly.
1988	 * It only checks the first long to be zero, and will use such mask
1989	 * as a terminator even if there was bits set after the first long.
1990	 *
1991	 * This should be fine since the available_scan_mask has already been
1992	 * sanity tested using iio_sanity_check_avail_scan_masks.
1993	 *
1994	 * See iio_scan_mask_match and iio_sanity_check_avail_scan_masks for
1995	 * more details
1996	 */
1997	av_masks = indio_dev->available_scan_masks;
1998	while (*av_masks) {
1999		if (indio_dev->active_scan_mask == av_masks)
2000			return i;
2001		av_masks += BITS_TO_LONGS(masklength);
2002		i++;
2003	}
2004
2005	dev_warn(indio_dev->dev.parent,
2006		 "active scan mask is not part of the available scan masks\n");
2007	return -EINVAL;
2008}
2009EXPORT_SYMBOL_GPL(iio_active_scan_mask_index);
2010
2011int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
2012{
2013	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2014	struct fwnode_handle *fwnode = NULL;
2015	int ret;
2016
2017	if (!indio_dev->info)
2018		return -EINVAL;
2019
2020	iio_dev_opaque->driver_module = this_mod;
2021
2022	/* If the calling driver did not initialize firmware node, do it here */
2023	if (dev_fwnode(&indio_dev->dev))
2024		fwnode = dev_fwnode(&indio_dev->dev);
2025	/* The default dummy IIO device has no parent */
2026	else if (indio_dev->dev.parent)
2027		fwnode = dev_fwnode(indio_dev->dev.parent);
2028	device_set_node(&indio_dev->dev, fwnode);
2029
2030	fwnode_property_read_string(fwnode, "label", &indio_dev->label);
2031
2032	ret = iio_check_unique_scan_index(indio_dev);
2033	if (ret < 0)
2034		return ret;
2035
2036	ret = iio_check_extended_name(indio_dev);
2037	if (ret < 0)
2038		return ret;
2039
2040	iio_device_register_debugfs(indio_dev);
2041
2042	ret = iio_buffers_alloc_sysfs_and_mask(indio_dev);
2043	if (ret) {
2044		dev_err(indio_dev->dev.parent,
2045			"Failed to create buffer sysfs interfaces\n");
2046		goto error_unreg_debugfs;
2047	}
2048
2049	if (indio_dev->available_scan_masks)
2050		iio_sanity_check_avail_scan_masks(indio_dev);
2051
2052	ret = iio_device_register_sysfs(indio_dev);
2053	if (ret) {
2054		dev_err(indio_dev->dev.parent,
2055			"Failed to register sysfs interfaces\n");
2056		goto error_buffer_free_sysfs;
2057	}
2058	ret = iio_device_register_eventset(indio_dev);
2059	if (ret) {
2060		dev_err(indio_dev->dev.parent,
2061			"Failed to register event set\n");
2062		goto error_free_sysfs;
2063	}
2064	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
2065		iio_device_register_trigger_consumer(indio_dev);
2066
2067	if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
2068		indio_dev->setup_ops == NULL)
2069		indio_dev->setup_ops = &noop_ring_setup_ops;
2070
2071	if (iio_dev_opaque->attached_buffers_cnt)
2072		cdev_init(&iio_dev_opaque->chrdev, &iio_buffer_fileops);
2073	else if (iio_dev_opaque->event_interface)
2074		cdev_init(&iio_dev_opaque->chrdev, &iio_event_fileops);
2075
2076	if (iio_dev_opaque->attached_buffers_cnt || iio_dev_opaque->event_interface) {
2077		indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), iio_dev_opaque->id);
2078		iio_dev_opaque->chrdev.owner = this_mod;
2079	}
2080
2081	/* assign device groups now; they should be all registered now */
2082	indio_dev->dev.groups = iio_dev_opaque->groups;
2083
2084	ret = cdev_device_add(&iio_dev_opaque->chrdev, &indio_dev->dev);
2085	if (ret < 0)
2086		goto error_unreg_eventset;
2087
2088	return 0;
2089
2090error_unreg_eventset:
2091	iio_device_unregister_eventset(indio_dev);
2092error_free_sysfs:
2093	iio_device_unregister_sysfs(indio_dev);
2094error_buffer_free_sysfs:
2095	iio_buffers_free_sysfs_and_mask(indio_dev);
2096error_unreg_debugfs:
2097	iio_device_unregister_debugfs(indio_dev);
2098	return ret;
2099}
2100EXPORT_SYMBOL(__iio_device_register);
2101
2102/**
2103 * iio_device_unregister() - unregister a device from the IIO subsystem
2104 * @indio_dev:		Device structure representing the device.
2105 */
2106void iio_device_unregister(struct iio_dev *indio_dev)
2107{
2108	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2109
2110	cdev_device_del(&iio_dev_opaque->chrdev, &indio_dev->dev);
2111
2112	scoped_guard(mutex, &iio_dev_opaque->info_exist_lock) {
2113		iio_device_unregister_debugfs(indio_dev);
2114
2115		iio_disable_all_buffers(indio_dev);
2116
2117		indio_dev->info = NULL;
2118
2119		iio_device_wakeup_eventset(indio_dev);
2120		iio_buffer_wakeup_poll(indio_dev);
2121	}
2122
2123	iio_buffers_free_sysfs_and_mask(indio_dev);
2124}
2125EXPORT_SYMBOL(iio_device_unregister);
2126
2127static void devm_iio_device_unreg(void *indio_dev)
2128{
2129	iio_device_unregister(indio_dev);
2130}
2131
2132int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
2133			       struct module *this_mod)
2134{
2135	int ret;
2136
2137	ret = __iio_device_register(indio_dev, this_mod);
2138	if (ret)
2139		return ret;
2140
2141	return devm_add_action_or_reset(dev, devm_iio_device_unreg, indio_dev);
2142}
2143EXPORT_SYMBOL_GPL(__devm_iio_device_register);
2144
2145/**
2146 * iio_device_claim_direct_mode - Keep device in direct mode
2147 * @indio_dev:	the iio_dev associated with the device
2148 *
2149 * If the device is in direct mode it is guaranteed to stay
2150 * that way until iio_device_release_direct_mode() is called.
2151 *
2152 * Use with iio_device_release_direct_mode()
2153 *
2154 * Returns: 0 on success, -EBUSY on failure.
2155 */
2156int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
2157{
2158	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2159
2160	mutex_lock(&iio_dev_opaque->mlock);
2161
2162	if (iio_buffer_enabled(indio_dev)) {
2163		mutex_unlock(&iio_dev_opaque->mlock);
2164		return -EBUSY;
2165	}
2166	return 0;
2167}
2168EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
2169
2170/**
2171 * iio_device_release_direct_mode - releases claim on direct mode
2172 * @indio_dev:	the iio_dev associated with the device
2173 *
2174 * Release the claim. Device is no longer guaranteed to stay
2175 * in direct mode.
2176 *
2177 * Use with iio_device_claim_direct_mode()
2178 */
2179void iio_device_release_direct_mode(struct iio_dev *indio_dev)
2180{
2181	mutex_unlock(&to_iio_dev_opaque(indio_dev)->mlock);
2182}
2183EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
2184
2185/**
2186 * iio_device_claim_buffer_mode - Keep device in buffer mode
2187 * @indio_dev:	the iio_dev associated with the device
2188 *
2189 * If the device is in buffer mode it is guaranteed to stay
2190 * that way until iio_device_release_buffer_mode() is called.
2191 *
2192 * Use with iio_device_release_buffer_mode().
2193 *
2194 * Returns: 0 on success, -EBUSY on failure.
2195 */
2196int iio_device_claim_buffer_mode(struct iio_dev *indio_dev)
2197{
2198	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2199
2200	mutex_lock(&iio_dev_opaque->mlock);
2201
2202	if (iio_buffer_enabled(indio_dev))
2203		return 0;
2204
2205	mutex_unlock(&iio_dev_opaque->mlock);
2206	return -EBUSY;
2207}
2208EXPORT_SYMBOL_GPL(iio_device_claim_buffer_mode);
2209
2210/**
2211 * iio_device_release_buffer_mode - releases claim on buffer mode
2212 * @indio_dev:	the iio_dev associated with the device
2213 *
2214 * Release the claim. Device is no longer guaranteed to stay
2215 * in buffer mode.
2216 *
2217 * Use with iio_device_claim_buffer_mode().
2218 */
2219void iio_device_release_buffer_mode(struct iio_dev *indio_dev)
2220{
2221	mutex_unlock(&to_iio_dev_opaque(indio_dev)->mlock);
2222}
2223EXPORT_SYMBOL_GPL(iio_device_release_buffer_mode);
2224
2225/**
2226 * iio_device_get_current_mode() - helper function providing read-only access to
2227 *				   the opaque @currentmode variable
2228 * @indio_dev:			   IIO device structure for device
2229 */
2230int iio_device_get_current_mode(struct iio_dev *indio_dev)
2231{
2232	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
2233
2234	return iio_dev_opaque->currentmode;
2235}
2236EXPORT_SYMBOL_GPL(iio_device_get_current_mode);
2237
2238subsys_initcall(iio_init);
2239module_exit(iio_exit);
2240
2241MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
2242MODULE_DESCRIPTION("Industrial I/O core");
2243MODULE_LICENSE("GPL");