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   1/* The industrial I/O core
   2 *
   3 * Copyright (c) 2008 Jonathan Cameron
   4 *
   5 * This program is free software; you can redistribute it and/or modify it
   6 * under the terms of the GNU General Public License version 2 as published by
   7 * the Free Software Foundation.
   8 *
   9 * Based on elements of hwmon and input subsystems.
  10 */
  11
  12#define pr_fmt(fmt) "iio-core: " fmt
  13
  14#include <linux/kernel.h>
  15#include <linux/module.h>
  16#include <linux/idr.h>
  17#include <linux/kdev_t.h>
  18#include <linux/err.h>
  19#include <linux/device.h>
  20#include <linux/fs.h>
  21#include <linux/poll.h>
  22#include <linux/sched.h>
  23#include <linux/wait.h>
  24#include <linux/cdev.h>
  25#include <linux/slab.h>
  26#include <linux/anon_inodes.h>
  27#include <linux/debugfs.h>
  28#include <linux/mutex.h>
  29#include <linux/iio/iio.h>
  30#include "iio_core.h"
  31#include "iio_core_trigger.h"
  32#include <linux/iio/sysfs.h>
  33#include <linux/iio/events.h>
  34#include <linux/iio/buffer.h>
  35#include <linux/iio/buffer_impl.h>
  36
  37/* IDA to assign each registered device a unique id */
  38static DEFINE_IDA(iio_ida);
  39
  40static dev_t iio_devt;
  41
  42#define IIO_DEV_MAX 256
  43struct bus_type iio_bus_type = {
  44	.name = "iio",
  45};
  46EXPORT_SYMBOL(iio_bus_type);
  47
  48static struct dentry *iio_debugfs_dentry;
  49
  50static const char * const iio_direction[] = {
  51	[0] = "in",
  52	[1] = "out",
  53};
  54
  55static const char * const iio_chan_type_name_spec[] = {
  56	[IIO_VOLTAGE] = "voltage",
  57	[IIO_CURRENT] = "current",
  58	[IIO_POWER] = "power",
  59	[IIO_ACCEL] = "accel",
  60	[IIO_ANGL_VEL] = "anglvel",
  61	[IIO_MAGN] = "magn",
  62	[IIO_LIGHT] = "illuminance",
  63	[IIO_INTENSITY] = "intensity",
  64	[IIO_PROXIMITY] = "proximity",
  65	[IIO_TEMP] = "temp",
  66	[IIO_INCLI] = "incli",
  67	[IIO_ROT] = "rot",
  68	[IIO_ANGL] = "angl",
  69	[IIO_TIMESTAMP] = "timestamp",
  70	[IIO_CAPACITANCE] = "capacitance",
  71	[IIO_ALTVOLTAGE] = "altvoltage",
  72	[IIO_CCT] = "cct",
  73	[IIO_PRESSURE] = "pressure",
  74	[IIO_HUMIDITYRELATIVE] = "humidityrelative",
  75	[IIO_ACTIVITY] = "activity",
  76	[IIO_STEPS] = "steps",
  77	[IIO_ENERGY] = "energy",
  78	[IIO_DISTANCE] = "distance",
  79	[IIO_VELOCITY] = "velocity",
  80	[IIO_CONCENTRATION] = "concentration",
  81	[IIO_RESISTANCE] = "resistance",
  82	[IIO_PH] = "ph",
  83	[IIO_UVINDEX] = "uvindex",
  84	[IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
  85	[IIO_COUNT] = "count",
  86	[IIO_INDEX] = "index",
  87	[IIO_GRAVITY]  = "gravity",
  88};
  89
  90static const char * const iio_modifier_names[] = {
  91	[IIO_MOD_X] = "x",
  92	[IIO_MOD_Y] = "y",
  93	[IIO_MOD_Z] = "z",
  94	[IIO_MOD_X_AND_Y] = "x&y",
  95	[IIO_MOD_X_AND_Z] = "x&z",
  96	[IIO_MOD_Y_AND_Z] = "y&z",
  97	[IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
  98	[IIO_MOD_X_OR_Y] = "x|y",
  99	[IIO_MOD_X_OR_Z] = "x|z",
 100	[IIO_MOD_Y_OR_Z] = "y|z",
 101	[IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
 102	[IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
 103	[IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
 104	[IIO_MOD_LIGHT_BOTH] = "both",
 105	[IIO_MOD_LIGHT_IR] = "ir",
 106	[IIO_MOD_LIGHT_CLEAR] = "clear",
 107	[IIO_MOD_LIGHT_RED] = "red",
 108	[IIO_MOD_LIGHT_GREEN] = "green",
 109	[IIO_MOD_LIGHT_BLUE] = "blue",
 110	[IIO_MOD_LIGHT_UV] = "uv",
 111	[IIO_MOD_QUATERNION] = "quaternion",
 112	[IIO_MOD_TEMP_AMBIENT] = "ambient",
 113	[IIO_MOD_TEMP_OBJECT] = "object",
 114	[IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
 115	[IIO_MOD_NORTH_TRUE] = "from_north_true",
 116	[IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
 117	[IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
 118	[IIO_MOD_RUNNING] = "running",
 119	[IIO_MOD_JOGGING] = "jogging",
 120	[IIO_MOD_WALKING] = "walking",
 121	[IIO_MOD_STILL] = "still",
 122	[IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
 123	[IIO_MOD_I] = "i",
 124	[IIO_MOD_Q] = "q",
 125	[IIO_MOD_CO2] = "co2",
 126	[IIO_MOD_VOC] = "voc",
 127};
 128
 129/* relies on pairs of these shared then separate */
 130static const char * const iio_chan_info_postfix[] = {
 131	[IIO_CHAN_INFO_RAW] = "raw",
 132	[IIO_CHAN_INFO_PROCESSED] = "input",
 133	[IIO_CHAN_INFO_SCALE] = "scale",
 134	[IIO_CHAN_INFO_OFFSET] = "offset",
 135	[IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
 136	[IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
 137	[IIO_CHAN_INFO_PEAK] = "peak_raw",
 138	[IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
 139	[IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
 140	[IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
 141	[IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
 142	= "filter_low_pass_3db_frequency",
 143	[IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
 144	= "filter_high_pass_3db_frequency",
 145	[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
 146	[IIO_CHAN_INFO_FREQUENCY] = "frequency",
 147	[IIO_CHAN_INFO_PHASE] = "phase",
 148	[IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 149	[IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
 150	[IIO_CHAN_INFO_INT_TIME] = "integration_time",
 151	[IIO_CHAN_INFO_ENABLE] = "en",
 152	[IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
 153	[IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
 154	[IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
 155	[IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
 156	[IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
 157	[IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
 158};
 159
 160/**
 161 * iio_find_channel_from_si() - get channel from its scan index
 162 * @indio_dev:		device
 163 * @si:			scan index to match
 164 */
 165const struct iio_chan_spec
 166*iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
 167{
 168	int i;
 169
 170	for (i = 0; i < indio_dev->num_channels; i++)
 171		if (indio_dev->channels[i].scan_index == si)
 172			return &indio_dev->channels[i];
 173	return NULL;
 174}
 175
 176/* This turns up an awful lot */
 177ssize_t iio_read_const_attr(struct device *dev,
 178			    struct device_attribute *attr,
 179			    char *buf)
 180{
 181	return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 182}
 183EXPORT_SYMBOL(iio_read_const_attr);
 184
 185static int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
 186{
 187	int ret;
 188	const struct iio_event_interface *ev_int = indio_dev->event_interface;
 189
 190	ret = mutex_lock_interruptible(&indio_dev->mlock);
 191	if (ret)
 192		return ret;
 193	if ((ev_int && iio_event_enabled(ev_int)) ||
 194	    iio_buffer_enabled(indio_dev)) {
 195		mutex_unlock(&indio_dev->mlock);
 196		return -EBUSY;
 197	}
 198	indio_dev->clock_id = clock_id;
 199	mutex_unlock(&indio_dev->mlock);
 200
 201	return 0;
 202}
 203
 204/**
 205 * iio_get_time_ns() - utility function to get a time stamp for events etc
 206 * @indio_dev: device
 207 */
 208s64 iio_get_time_ns(const struct iio_dev *indio_dev)
 209{
 210	struct timespec tp;
 211
 212	switch (iio_device_get_clock(indio_dev)) {
 213	case CLOCK_REALTIME:
 214		ktime_get_real_ts(&tp);
 215		break;
 216	case CLOCK_MONOTONIC:
 217		ktime_get_ts(&tp);
 218		break;
 219	case CLOCK_MONOTONIC_RAW:
 220		getrawmonotonic(&tp);
 221		break;
 222	case CLOCK_REALTIME_COARSE:
 223		tp = current_kernel_time();
 224		break;
 225	case CLOCK_MONOTONIC_COARSE:
 226		tp = get_monotonic_coarse();
 227		break;
 228	case CLOCK_BOOTTIME:
 229		get_monotonic_boottime(&tp);
 230		break;
 231	case CLOCK_TAI:
 232		timekeeping_clocktai(&tp);
 233		break;
 234	default:
 235		BUG();
 236	}
 237
 238	return timespec_to_ns(&tp);
 239}
 240EXPORT_SYMBOL(iio_get_time_ns);
 241
 242/**
 243 * iio_get_time_res() - utility function to get time stamp clock resolution in
 244 *                      nano seconds.
 245 * @indio_dev: device
 246 */
 247unsigned int iio_get_time_res(const struct iio_dev *indio_dev)
 248{
 249	switch (iio_device_get_clock(indio_dev)) {
 250	case CLOCK_REALTIME:
 251	case CLOCK_MONOTONIC:
 252	case CLOCK_MONOTONIC_RAW:
 253	case CLOCK_BOOTTIME:
 254	case CLOCK_TAI:
 255		return hrtimer_resolution;
 256	case CLOCK_REALTIME_COARSE:
 257	case CLOCK_MONOTONIC_COARSE:
 258		return LOW_RES_NSEC;
 259	default:
 260		BUG();
 261	}
 262}
 263EXPORT_SYMBOL(iio_get_time_res);
 264
 265static int __init iio_init(void)
 266{
 267	int ret;
 268
 269	/* Register sysfs bus */
 270	ret  = bus_register(&iio_bus_type);
 271	if (ret < 0) {
 272		pr_err("could not register bus type\n");
 273		goto error_nothing;
 274	}
 275
 276	ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 277	if (ret < 0) {
 278		pr_err("failed to allocate char dev region\n");
 279		goto error_unregister_bus_type;
 280	}
 281
 282	iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 283
 284	return 0;
 285
 286error_unregister_bus_type:
 287	bus_unregister(&iio_bus_type);
 288error_nothing:
 289	return ret;
 290}
 291
 292static void __exit iio_exit(void)
 293{
 294	if (iio_devt)
 295		unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 296	bus_unregister(&iio_bus_type);
 297	debugfs_remove(iio_debugfs_dentry);
 298}
 299
 300#if defined(CONFIG_DEBUG_FS)
 301static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 302			      size_t count, loff_t *ppos)
 303{
 304	struct iio_dev *indio_dev = file->private_data;
 305	char buf[20];
 306	unsigned val = 0;
 307	ssize_t len;
 308	int ret;
 309
 310	ret = indio_dev->info->debugfs_reg_access(indio_dev,
 311						  indio_dev->cached_reg_addr,
 312						  0, &val);
 313	if (ret) {
 314		dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 315		return ret;
 316	}
 317
 318	len = snprintf(buf, sizeof(buf), "0x%X\n", val);
 319
 320	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
 321}
 322
 323static ssize_t iio_debugfs_write_reg(struct file *file,
 324		     const char __user *userbuf, size_t count, loff_t *ppos)
 325{
 326	struct iio_dev *indio_dev = file->private_data;
 327	unsigned reg, val;
 328	char buf[80];
 329	int ret;
 330
 331	count = min_t(size_t, count, (sizeof(buf)-1));
 332	if (copy_from_user(buf, userbuf, count))
 333		return -EFAULT;
 334
 335	buf[count] = 0;
 336
 337	ret = sscanf(buf, "%i %i", &reg, &val);
 338
 339	switch (ret) {
 340	case 1:
 341		indio_dev->cached_reg_addr = reg;
 342		break;
 343	case 2:
 344		indio_dev->cached_reg_addr = reg;
 345		ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 346							  val, NULL);
 347		if (ret) {
 348			dev_err(indio_dev->dev.parent, "%s: write failed\n",
 349				__func__);
 350			return ret;
 351		}
 352		break;
 353	default:
 354		return -EINVAL;
 355	}
 356
 357	return count;
 358}
 359
 360static const struct file_operations iio_debugfs_reg_fops = {
 361	.open = simple_open,
 362	.read = iio_debugfs_read_reg,
 363	.write = iio_debugfs_write_reg,
 364};
 365
 366static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 367{
 368	debugfs_remove_recursive(indio_dev->debugfs_dentry);
 369}
 370
 371static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 372{
 373	struct dentry *d;
 374
 375	if (indio_dev->info->debugfs_reg_access == NULL)
 376		return 0;
 377
 378	if (!iio_debugfs_dentry)
 379		return 0;
 380
 381	indio_dev->debugfs_dentry =
 382		debugfs_create_dir(dev_name(&indio_dev->dev),
 383				   iio_debugfs_dentry);
 384	if (indio_dev->debugfs_dentry == NULL) {
 385		dev_warn(indio_dev->dev.parent,
 386			 "Failed to create debugfs directory\n");
 387		return -EFAULT;
 388	}
 389
 390	d = debugfs_create_file("direct_reg_access", 0644,
 391				indio_dev->debugfs_dentry,
 392				indio_dev, &iio_debugfs_reg_fops);
 393	if (!d) {
 394		iio_device_unregister_debugfs(indio_dev);
 395		return -ENOMEM;
 396	}
 397
 398	return 0;
 399}
 400#else
 401static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 402{
 403	return 0;
 404}
 405
 406static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 407{
 408}
 409#endif /* CONFIG_DEBUG_FS */
 410
 411static ssize_t iio_read_channel_ext_info(struct device *dev,
 412				     struct device_attribute *attr,
 413				     char *buf)
 414{
 415	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 416	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 417	const struct iio_chan_spec_ext_info *ext_info;
 418
 419	ext_info = &this_attr->c->ext_info[this_attr->address];
 420
 421	return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
 422}
 423
 424static ssize_t iio_write_channel_ext_info(struct device *dev,
 425				     struct device_attribute *attr,
 426				     const char *buf,
 427					 size_t len)
 428{
 429	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 430	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 431	const struct iio_chan_spec_ext_info *ext_info;
 432
 433	ext_info = &this_attr->c->ext_info[this_attr->address];
 434
 435	return ext_info->write(indio_dev, ext_info->private,
 436			       this_attr->c, buf, len);
 437}
 438
 439ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 440	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 441{
 442	const struct iio_enum *e = (const struct iio_enum *)priv;
 443	unsigned int i;
 444	size_t len = 0;
 445
 446	if (!e->num_items)
 447		return 0;
 448
 449	for (i = 0; i < e->num_items; ++i)
 450		len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
 451
 452	/* replace last space with a newline */
 453	buf[len - 1] = '\n';
 454
 455	return len;
 456}
 457EXPORT_SYMBOL_GPL(iio_enum_available_read);
 458
 459ssize_t iio_enum_read(struct iio_dev *indio_dev,
 460	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 461{
 462	const struct iio_enum *e = (const struct iio_enum *)priv;
 463	int i;
 464
 465	if (!e->get)
 466		return -EINVAL;
 467
 468	i = e->get(indio_dev, chan);
 469	if (i < 0)
 470		return i;
 471	else if (i >= e->num_items)
 472		return -EINVAL;
 473
 474	return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
 475}
 476EXPORT_SYMBOL_GPL(iio_enum_read);
 477
 478ssize_t iio_enum_write(struct iio_dev *indio_dev,
 479	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 480	size_t len)
 481{
 482	const struct iio_enum *e = (const struct iio_enum *)priv;
 483	int ret;
 484
 485	if (!e->set)
 486		return -EINVAL;
 487
 488	ret = __sysfs_match_string(e->items, e->num_items, buf);
 489	if (ret < 0)
 490		return ret;
 491
 492	ret = e->set(indio_dev, chan, ret);
 493	return ret ? ret : len;
 494}
 495EXPORT_SYMBOL_GPL(iio_enum_write);
 496
 497static const struct iio_mount_matrix iio_mount_idmatrix = {
 498	.rotation = {
 499		"1", "0", "0",
 500		"0", "1", "0",
 501		"0", "0", "1"
 502	}
 503};
 504
 505static int iio_setup_mount_idmatrix(const struct device *dev,
 506				    struct iio_mount_matrix *matrix)
 507{
 508	*matrix = iio_mount_idmatrix;
 509	dev_info(dev, "mounting matrix not found: using identity...\n");
 510	return 0;
 511}
 512
 513ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
 514			      const struct iio_chan_spec *chan, char *buf)
 515{
 516	const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
 517					      priv)(indio_dev, chan);
 518
 519	if (IS_ERR(mtx))
 520		return PTR_ERR(mtx);
 521
 522	if (!mtx)
 523		mtx = &iio_mount_idmatrix;
 524
 525	return snprintf(buf, PAGE_SIZE, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
 526			mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
 527			mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
 528			mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
 529}
 530EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
 531
 532/**
 533 * of_iio_read_mount_matrix() - retrieve iio device mounting matrix from
 534 *                              device-tree "mount-matrix" property
 535 * @dev:	device the mounting matrix property is assigned to
 536 * @propname:	device specific mounting matrix property name
 537 * @matrix:	where to store retrieved matrix
 538 *
 539 * If device is assigned no mounting matrix property, a default 3x3 identity
 540 * matrix will be filled in.
 541 *
 542 * Return: 0 if success, or a negative error code on failure.
 543 */
 544#ifdef CONFIG_OF
 545int of_iio_read_mount_matrix(const struct device *dev,
 546			     const char *propname,
 547			     struct iio_mount_matrix *matrix)
 548{
 549	if (dev->of_node) {
 550		int err = of_property_read_string_array(dev->of_node,
 551				propname, matrix->rotation,
 552				ARRAY_SIZE(iio_mount_idmatrix.rotation));
 553
 554		if (err == ARRAY_SIZE(iio_mount_idmatrix.rotation))
 555			return 0;
 556
 557		if (err >= 0)
 558			/* Invalid number of matrix entries. */
 559			return -EINVAL;
 560
 561		if (err != -EINVAL)
 562			/* Invalid matrix declaration format. */
 563			return err;
 564	}
 565
 566	/* Matrix was not declared at all: fallback to identity. */
 567	return iio_setup_mount_idmatrix(dev, matrix);
 568}
 569#else
 570int of_iio_read_mount_matrix(const struct device *dev,
 571			     const char *propname,
 572			     struct iio_mount_matrix *matrix)
 573{
 574	return iio_setup_mount_idmatrix(dev, matrix);
 575}
 576#endif
 577EXPORT_SYMBOL(of_iio_read_mount_matrix);
 578
 579static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
 580				  int size, const int *vals)
 581{
 582	unsigned long long tmp;
 583	int tmp0, tmp1;
 584	bool scale_db = false;
 585
 586	switch (type) {
 587	case IIO_VAL_INT:
 588		return snprintf(buf, len, "%d", vals[0]);
 589	case IIO_VAL_INT_PLUS_MICRO_DB:
 590		scale_db = true;
 591		/* fall through */
 592	case IIO_VAL_INT_PLUS_MICRO:
 593		if (vals[1] < 0)
 594			return snprintf(buf, len, "-%d.%06u%s", abs(vals[0]),
 595					-vals[1], scale_db ? " dB" : "");
 596		else
 597			return snprintf(buf, len, "%d.%06u%s", vals[0], vals[1],
 598					scale_db ? " dB" : "");
 599	case IIO_VAL_INT_PLUS_NANO:
 600		if (vals[1] < 0)
 601			return snprintf(buf, len, "-%d.%09u", abs(vals[0]),
 602					-vals[1]);
 603		else
 604			return snprintf(buf, len, "%d.%09u", vals[0], vals[1]);
 605	case IIO_VAL_FRACTIONAL:
 606		tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
 607		tmp1 = vals[1];
 608		tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1);
 609		return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 610	case IIO_VAL_FRACTIONAL_LOG2:
 611		tmp = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
 612		tmp0 = (int)div_s64_rem(tmp, 1000000000LL, &tmp1);
 613		return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 614	case IIO_VAL_INT_MULTIPLE:
 615	{
 616		int i;
 617		int l = 0;
 618
 619		for (i = 0; i < size; ++i) {
 620			l += snprintf(&buf[l], len - l, "%d ", vals[i]);
 621			if (l >= len)
 622				break;
 623		}
 624		return l;
 625	}
 626	default:
 627		return 0;
 628	}
 629}
 630
 631/**
 632 * iio_format_value() - Formats a IIO value into its string representation
 633 * @buf:	The buffer to which the formatted value gets written
 634 *		which is assumed to be big enough (i.e. PAGE_SIZE).
 635 * @type:	One of the IIO_VAL_* constants. This decides how the val
 636 *		and val2 parameters are formatted.
 637 * @size:	Number of IIO value entries contained in vals
 638 * @vals:	Pointer to the values, exact meaning depends on the
 639 *		type parameter.
 640 *
 641 * Return: 0 by default, a negative number on failure or the
 642 *	   total number of characters written for a type that belongs
 643 *	   to the IIO_VAL_* constant.
 644 */
 645ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
 646{
 647	ssize_t len;
 648
 649	len = __iio_format_value(buf, PAGE_SIZE, type, size, vals);
 650	if (len >= PAGE_SIZE - 1)
 651		return -EFBIG;
 652
 653	return len + sprintf(buf + len, "\n");
 654}
 655EXPORT_SYMBOL_GPL(iio_format_value);
 656
 657static ssize_t iio_read_channel_info(struct device *dev,
 658				     struct device_attribute *attr,
 659				     char *buf)
 660{
 661	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 662	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 663	int vals[INDIO_MAX_RAW_ELEMENTS];
 664	int ret;
 665	int val_len = 2;
 666
 667	if (indio_dev->info->read_raw_multi)
 668		ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
 669							INDIO_MAX_RAW_ELEMENTS,
 670							vals, &val_len,
 671							this_attr->address);
 672	else
 673		ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 674				    &vals[0], &vals[1], this_attr->address);
 675
 676	if (ret < 0)
 677		return ret;
 678
 679	return iio_format_value(buf, ret, val_len, vals);
 680}
 681
 682static ssize_t iio_format_avail_list(char *buf, const int *vals,
 683				     int type, int length)
 684{
 685	int i;
 686	ssize_t len = 0;
 687
 688	switch (type) {
 689	case IIO_VAL_INT:
 690		for (i = 0; i < length; i++) {
 691			len += __iio_format_value(buf + len, PAGE_SIZE - len,
 692						  type, 1, &vals[i]);
 693			if (len >= PAGE_SIZE)
 694				return -EFBIG;
 695			if (i < length - 1)
 696				len += snprintf(buf + len, PAGE_SIZE - len,
 697						" ");
 698			else
 699				len += snprintf(buf + len, PAGE_SIZE - len,
 700						"\n");
 701			if (len >= PAGE_SIZE)
 702				return -EFBIG;
 703		}
 704		break;
 705	default:
 706		for (i = 0; i < length / 2; i++) {
 707			len += __iio_format_value(buf + len, PAGE_SIZE - len,
 708						  type, 2, &vals[i * 2]);
 709			if (len >= PAGE_SIZE)
 710				return -EFBIG;
 711			if (i < length / 2 - 1)
 712				len += snprintf(buf + len, PAGE_SIZE - len,
 713						" ");
 714			else
 715				len += snprintf(buf + len, PAGE_SIZE - len,
 716						"\n");
 717			if (len >= PAGE_SIZE)
 718				return -EFBIG;
 719		}
 720	}
 721
 722	return len;
 723}
 724
 725static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
 726{
 727	int i;
 728	ssize_t len;
 729
 730	len = snprintf(buf, PAGE_SIZE, "[");
 731	switch (type) {
 732	case IIO_VAL_INT:
 733		for (i = 0; i < 3; i++) {
 734			len += __iio_format_value(buf + len, PAGE_SIZE - len,
 735						  type, 1, &vals[i]);
 736			if (len >= PAGE_SIZE)
 737				return -EFBIG;
 738			if (i < 2)
 739				len += snprintf(buf + len, PAGE_SIZE - len,
 740						" ");
 741			else
 742				len += snprintf(buf + len, PAGE_SIZE - len,
 743						"]\n");
 744			if (len >= PAGE_SIZE)
 745				return -EFBIG;
 746		}
 747		break;
 748	default:
 749		for (i = 0; i < 3; i++) {
 750			len += __iio_format_value(buf + len, PAGE_SIZE - len,
 751						  type, 2, &vals[i * 2]);
 752			if (len >= PAGE_SIZE)
 753				return -EFBIG;
 754			if (i < 2)
 755				len += snprintf(buf + len, PAGE_SIZE - len,
 756						" ");
 757			else
 758				len += snprintf(buf + len, PAGE_SIZE - len,
 759						"]\n");
 760			if (len >= PAGE_SIZE)
 761				return -EFBIG;
 762		}
 763	}
 764
 765	return len;
 766}
 767
 768static ssize_t iio_read_channel_info_avail(struct device *dev,
 769					   struct device_attribute *attr,
 770					   char *buf)
 771{
 772	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 773	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 774	const int *vals;
 775	int ret;
 776	int length;
 777	int type;
 778
 779	ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
 780					  &vals, &type, &length,
 781					  this_attr->address);
 782
 783	if (ret < 0)
 784		return ret;
 785	switch (ret) {
 786	case IIO_AVAIL_LIST:
 787		return iio_format_avail_list(buf, vals, type, length);
 788	case IIO_AVAIL_RANGE:
 789		return iio_format_avail_range(buf, vals, type);
 790	default:
 791		return -EINVAL;
 792	}
 793}
 794
 795/**
 796 * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 797 * @str: The string to parse
 798 * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 799 * @integer: The integer part of the number
 800 * @fract: The fractional part of the number
 801 *
 802 * Returns 0 on success, or a negative error code if the string could not be
 803 * parsed.
 804 */
 805int iio_str_to_fixpoint(const char *str, int fract_mult,
 806	int *integer, int *fract)
 807{
 808	int i = 0, f = 0;
 809	bool integer_part = true, negative = false;
 810
 811	if (fract_mult == 0) {
 812		*fract = 0;
 813
 814		return kstrtoint(str, 0, integer);
 815	}
 816
 817	if (str[0] == '-') {
 818		negative = true;
 819		str++;
 820	} else if (str[0] == '+') {
 821		str++;
 822	}
 823
 824	while (*str) {
 825		if ('0' <= *str && *str <= '9') {
 826			if (integer_part) {
 827				i = i * 10 + *str - '0';
 828			} else {
 829				f += fract_mult * (*str - '0');
 830				fract_mult /= 10;
 831			}
 832		} else if (*str == '\n') {
 833			if (*(str + 1) == '\0')
 834				break;
 835			else
 836				return -EINVAL;
 837		} else if (*str == '.' && integer_part) {
 838			integer_part = false;
 839		} else {
 840			return -EINVAL;
 841		}
 842		str++;
 843	}
 844
 845	if (negative) {
 846		if (i)
 847			i = -i;
 848		else
 849			f = -f;
 850	}
 851
 852	*integer = i;
 853	*fract = f;
 854
 855	return 0;
 856}
 857EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 858
 859static ssize_t iio_write_channel_info(struct device *dev,
 860				      struct device_attribute *attr,
 861				      const char *buf,
 862				      size_t len)
 863{
 864	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 865	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 866	int ret, fract_mult = 100000;
 867	int integer, fract;
 868
 869	/* Assumes decimal - precision based on number of digits */
 870	if (!indio_dev->info->write_raw)
 871		return -EINVAL;
 872
 873	if (indio_dev->info->write_raw_get_fmt)
 874		switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 875			this_attr->c, this_attr->address)) {
 876		case IIO_VAL_INT:
 877			fract_mult = 0;
 878			break;
 879		case IIO_VAL_INT_PLUS_MICRO:
 880			fract_mult = 100000;
 881			break;
 882		case IIO_VAL_INT_PLUS_NANO:
 883			fract_mult = 100000000;
 884			break;
 885		default:
 886			return -EINVAL;
 887		}
 888
 889	ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
 890	if (ret)
 891		return ret;
 892
 893	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 894					 integer, fract, this_attr->address);
 895	if (ret)
 896		return ret;
 897
 898	return len;
 899}
 900
 901static
 902int __iio_device_attr_init(struct device_attribute *dev_attr,
 903			   const char *postfix,
 904			   struct iio_chan_spec const *chan,
 905			   ssize_t (*readfunc)(struct device *dev,
 906					       struct device_attribute *attr,
 907					       char *buf),
 908			   ssize_t (*writefunc)(struct device *dev,
 909						struct device_attribute *attr,
 910						const char *buf,
 911						size_t len),
 912			   enum iio_shared_by shared_by)
 913{
 914	int ret = 0;
 915	char *name = NULL;
 916	char *full_postfix;
 917	sysfs_attr_init(&dev_attr->attr);
 918
 919	/* Build up postfix of <extend_name>_<modifier>_postfix */
 920	if (chan->modified && (shared_by == IIO_SEPARATE)) {
 921		if (chan->extend_name)
 922			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 923						 iio_modifier_names[chan
 924								    ->channel2],
 925						 chan->extend_name,
 926						 postfix);
 927		else
 928			full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 929						 iio_modifier_names[chan
 930								    ->channel2],
 931						 postfix);
 932	} else {
 933		if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
 934			full_postfix = kstrdup(postfix, GFP_KERNEL);
 935		else
 936			full_postfix = kasprintf(GFP_KERNEL,
 937						 "%s_%s",
 938						 chan->extend_name,
 939						 postfix);
 940	}
 941	if (full_postfix == NULL)
 942		return -ENOMEM;
 943
 944	if (chan->differential) { /* Differential can not have modifier */
 945		switch (shared_by) {
 946		case IIO_SHARED_BY_ALL:
 947			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 948			break;
 949		case IIO_SHARED_BY_DIR:
 950			name = kasprintf(GFP_KERNEL, "%s_%s",
 951						iio_direction[chan->output],
 952						full_postfix);
 953			break;
 954		case IIO_SHARED_BY_TYPE:
 955			name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 956					    iio_direction[chan->output],
 957					    iio_chan_type_name_spec[chan->type],
 958					    iio_chan_type_name_spec[chan->type],
 959					    full_postfix);
 960			break;
 961		case IIO_SEPARATE:
 962			if (!chan->indexed) {
 963				WARN(1, "Differential channels must be indexed\n");
 964				ret = -EINVAL;
 965				goto error_free_full_postfix;
 966			}
 967			name = kasprintf(GFP_KERNEL,
 968					    "%s_%s%d-%s%d_%s",
 969					    iio_direction[chan->output],
 970					    iio_chan_type_name_spec[chan->type],
 971					    chan->channel,
 972					    iio_chan_type_name_spec[chan->type],
 973					    chan->channel2,
 974					    full_postfix);
 975			break;
 976		}
 977	} else { /* Single ended */
 978		switch (shared_by) {
 979		case IIO_SHARED_BY_ALL:
 980			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 981			break;
 982		case IIO_SHARED_BY_DIR:
 983			name = kasprintf(GFP_KERNEL, "%s_%s",
 984						iio_direction[chan->output],
 985						full_postfix);
 986			break;
 987		case IIO_SHARED_BY_TYPE:
 988			name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 989					    iio_direction[chan->output],
 990					    iio_chan_type_name_spec[chan->type],
 991					    full_postfix);
 992			break;
 993
 994		case IIO_SEPARATE:
 995			if (chan->indexed)
 996				name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 997						    iio_direction[chan->output],
 998						    iio_chan_type_name_spec[chan->type],
 999						    chan->channel,
1000						    full_postfix);
1001			else
1002				name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1003						    iio_direction[chan->output],
1004						    iio_chan_type_name_spec[chan->type],
1005						    full_postfix);
1006			break;
1007		}
1008	}
1009	if (name == NULL) {
1010		ret = -ENOMEM;
1011		goto error_free_full_postfix;
1012	}
1013	dev_attr->attr.name = name;
1014
1015	if (readfunc) {
1016		dev_attr->attr.mode |= S_IRUGO;
1017		dev_attr->show = readfunc;
1018	}
1019
1020	if (writefunc) {
1021		dev_attr->attr.mode |= S_IWUSR;
1022		dev_attr->store = writefunc;
1023	}
1024
1025error_free_full_postfix:
1026	kfree(full_postfix);
1027
1028	return ret;
1029}
1030
1031static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1032{
1033	kfree(dev_attr->attr.name);
1034}
1035
1036int __iio_add_chan_devattr(const char *postfix,
1037			   struct iio_chan_spec const *chan,
1038			   ssize_t (*readfunc)(struct device *dev,
1039					       struct device_attribute *attr,
1040					       char *buf),
1041			   ssize_t (*writefunc)(struct device *dev,
1042						struct device_attribute *attr,
1043						const char *buf,
1044						size_t len),
1045			   u64 mask,
1046			   enum iio_shared_by shared_by,
1047			   struct device *dev,
1048			   struct list_head *attr_list)
1049{
1050	int ret;
1051	struct iio_dev_attr *iio_attr, *t;
1052
1053	iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1054	if (iio_attr == NULL)
1055		return -ENOMEM;
1056	ret = __iio_device_attr_init(&iio_attr->dev_attr,
1057				     postfix, chan,
1058				     readfunc, writefunc, shared_by);
1059	if (ret)
1060		goto error_iio_dev_attr_free;
1061	iio_attr->c = chan;
1062	iio_attr->address = mask;
1063	list_for_each_entry(t, attr_list, l)
1064		if (strcmp(t->dev_attr.attr.name,
1065			   iio_attr->dev_attr.attr.name) == 0) {
1066			if (shared_by == IIO_SEPARATE)
1067				dev_err(dev, "tried to double register : %s\n",
1068					t->dev_attr.attr.name);
1069			ret = -EBUSY;
1070			goto error_device_attr_deinit;
1071		}
1072	list_add(&iio_attr->l, attr_list);
1073
1074	return 0;
1075
1076error_device_attr_deinit:
1077	__iio_device_attr_deinit(&iio_attr->dev_attr);
1078error_iio_dev_attr_free:
1079	kfree(iio_attr);
1080	return ret;
1081}
1082
1083static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1084					 struct iio_chan_spec const *chan,
1085					 enum iio_shared_by shared_by,
1086					 const long *infomask)
1087{
1088	int i, ret, attrcount = 0;
1089
1090	for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1091		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1092			return -EINVAL;
1093		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1094					     chan,
1095					     &iio_read_channel_info,
1096					     &iio_write_channel_info,
1097					     i,
1098					     shared_by,
1099					     &indio_dev->dev,
1100					     &indio_dev->channel_attr_list);
1101		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1102			continue;
1103		else if (ret < 0)
1104			return ret;
1105		attrcount++;
1106	}
1107
1108	return attrcount;
1109}
1110
1111static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1112					       struct iio_chan_spec const *chan,
1113					       enum iio_shared_by shared_by,
1114					       const long *infomask)
1115{
1116	int i, ret, attrcount = 0;
1117	char *avail_postfix;
1118
1119	for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1120		avail_postfix = kasprintf(GFP_KERNEL,
1121					  "%s_available",
1122					  iio_chan_info_postfix[i]);
1123		if (!avail_postfix)
1124			return -ENOMEM;
1125
1126		ret = __iio_add_chan_devattr(avail_postfix,
1127					     chan,
1128					     &iio_read_channel_info_avail,
1129					     NULL,
1130					     i,
1131					     shared_by,
1132					     &indio_dev->dev,
1133					     &indio_dev->channel_attr_list);
1134		kfree(avail_postfix);
1135		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1136			continue;
1137		else if (ret < 0)
1138			return ret;
1139		attrcount++;
1140	}
1141
1142	return attrcount;
1143}
1144
1145static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1146					struct iio_chan_spec const *chan)
1147{
1148	int ret, attrcount = 0;
1149	const struct iio_chan_spec_ext_info *ext_info;
1150
1151	if (chan->channel < 0)
1152		return 0;
1153	ret = iio_device_add_info_mask_type(indio_dev, chan,
1154					    IIO_SEPARATE,
1155					    &chan->info_mask_separate);
1156	if (ret < 0)
1157		return ret;
1158	attrcount += ret;
1159
1160	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1161						  IIO_SEPARATE,
1162						  &chan->
1163						  info_mask_separate_available);
1164	if (ret < 0)
1165		return ret;
1166	attrcount += ret;
1167
1168	ret = iio_device_add_info_mask_type(indio_dev, chan,
1169					    IIO_SHARED_BY_TYPE,
1170					    &chan->info_mask_shared_by_type);
1171	if (ret < 0)
1172		return ret;
1173	attrcount += ret;
1174
1175	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1176						  IIO_SHARED_BY_TYPE,
1177						  &chan->
1178						  info_mask_shared_by_type_available);
1179	if (ret < 0)
1180		return ret;
1181	attrcount += ret;
1182
1183	ret = iio_device_add_info_mask_type(indio_dev, chan,
1184					    IIO_SHARED_BY_DIR,
1185					    &chan->info_mask_shared_by_dir);
1186	if (ret < 0)
1187		return ret;
1188	attrcount += ret;
1189
1190	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1191						  IIO_SHARED_BY_DIR,
1192						  &chan->info_mask_shared_by_dir_available);
1193	if (ret < 0)
1194		return ret;
1195	attrcount += ret;
1196
1197	ret = iio_device_add_info_mask_type(indio_dev, chan,
1198					    IIO_SHARED_BY_ALL,
1199					    &chan->info_mask_shared_by_all);
1200	if (ret < 0)
1201		return ret;
1202	attrcount += ret;
1203
1204	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1205						  IIO_SHARED_BY_ALL,
1206						  &chan->info_mask_shared_by_all_available);
1207	if (ret < 0)
1208		return ret;
1209	attrcount += ret;
1210
1211	if (chan->ext_info) {
1212		unsigned int i = 0;
1213		for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1214			ret = __iio_add_chan_devattr(ext_info->name,
1215					chan,
1216					ext_info->read ?
1217					    &iio_read_channel_ext_info : NULL,
1218					ext_info->write ?
1219					    &iio_write_channel_ext_info : NULL,
1220					i,
1221					ext_info->shared,
1222					&indio_dev->dev,
1223					&indio_dev->channel_attr_list);
1224			i++;
1225			if (ret == -EBUSY && ext_info->shared)
1226				continue;
1227
1228			if (ret)
1229				return ret;
1230
1231			attrcount++;
1232		}
1233	}
1234
1235	return attrcount;
1236}
1237
1238/**
1239 * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1240 * @attr_list: List of IIO device attributes
1241 *
1242 * This function frees the memory allocated for each of the IIO device
1243 * attributes in the list.
1244 */
1245void iio_free_chan_devattr_list(struct list_head *attr_list)
1246{
1247	struct iio_dev_attr *p, *n;
1248
1249	list_for_each_entry_safe(p, n, attr_list, l) {
1250		kfree(p->dev_attr.attr.name);
1251		list_del(&p->l);
1252		kfree(p);
1253	}
1254}
1255
1256static ssize_t iio_show_dev_name(struct device *dev,
1257				 struct device_attribute *attr,
1258				 char *buf)
1259{
1260	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1261	return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
1262}
1263
1264static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
1265
1266static ssize_t iio_show_timestamp_clock(struct device *dev,
1267					struct device_attribute *attr,
1268					char *buf)
1269{
1270	const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1271	const clockid_t clk = iio_device_get_clock(indio_dev);
1272	const char *name;
1273	ssize_t sz;
1274
1275	switch (clk) {
1276	case CLOCK_REALTIME:
1277		name = "realtime\n";
1278		sz = sizeof("realtime\n");
1279		break;
1280	case CLOCK_MONOTONIC:
1281		name = "monotonic\n";
1282		sz = sizeof("monotonic\n");
1283		break;
1284	case CLOCK_MONOTONIC_RAW:
1285		name = "monotonic_raw\n";
1286		sz = sizeof("monotonic_raw\n");
1287		break;
1288	case CLOCK_REALTIME_COARSE:
1289		name = "realtime_coarse\n";
1290		sz = sizeof("realtime_coarse\n");
1291		break;
1292	case CLOCK_MONOTONIC_COARSE:
1293		name = "monotonic_coarse\n";
1294		sz = sizeof("monotonic_coarse\n");
1295		break;
1296	case CLOCK_BOOTTIME:
1297		name = "boottime\n";
1298		sz = sizeof("boottime\n");
1299		break;
1300	case CLOCK_TAI:
1301		name = "tai\n";
1302		sz = sizeof("tai\n");
1303		break;
1304	default:
1305		BUG();
1306	}
1307
1308	memcpy(buf, name, sz);
1309	return sz;
1310}
1311
1312static ssize_t iio_store_timestamp_clock(struct device *dev,
1313					 struct device_attribute *attr,
1314					 const char *buf, size_t len)
1315{
1316	clockid_t clk;
1317	int ret;
1318
1319	if (sysfs_streq(buf, "realtime"))
1320		clk = CLOCK_REALTIME;
1321	else if (sysfs_streq(buf, "monotonic"))
1322		clk = CLOCK_MONOTONIC;
1323	else if (sysfs_streq(buf, "monotonic_raw"))
1324		clk = CLOCK_MONOTONIC_RAW;
1325	else if (sysfs_streq(buf, "realtime_coarse"))
1326		clk = CLOCK_REALTIME_COARSE;
1327	else if (sysfs_streq(buf, "monotonic_coarse"))
1328		clk = CLOCK_MONOTONIC_COARSE;
1329	else if (sysfs_streq(buf, "boottime"))
1330		clk = CLOCK_BOOTTIME;
1331	else if (sysfs_streq(buf, "tai"))
1332		clk = CLOCK_TAI;
1333	else
1334		return -EINVAL;
1335
1336	ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1337	if (ret)
1338		return ret;
1339
1340	return len;
1341}
1342
1343static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1344		   iio_show_timestamp_clock, iio_store_timestamp_clock);
1345
1346static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1347{
1348	int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1349	struct iio_dev_attr *p;
1350	struct attribute **attr, *clk = NULL;
1351
1352	/* First count elements in any existing group */
1353	if (indio_dev->info->attrs) {
1354		attr = indio_dev->info->attrs->attrs;
1355		while (*attr++ != NULL)
1356			attrcount_orig++;
1357	}
1358	attrcount = attrcount_orig;
1359	/*
1360	 * New channel registration method - relies on the fact a group does
1361	 * not need to be initialized if its name is NULL.
1362	 */
1363	if (indio_dev->channels)
1364		for (i = 0; i < indio_dev->num_channels; i++) {
1365			const struct iio_chan_spec *chan =
1366				&indio_dev->channels[i];
1367
1368			if (chan->type == IIO_TIMESTAMP)
1369				clk = &dev_attr_current_timestamp_clock.attr;
1370
1371			ret = iio_device_add_channel_sysfs(indio_dev, chan);
1372			if (ret < 0)
1373				goto error_clear_attrs;
1374			attrcount += ret;
1375		}
1376
1377	if (indio_dev->event_interface)
1378		clk = &dev_attr_current_timestamp_clock.attr;
1379
1380	if (indio_dev->name)
1381		attrcount++;
1382	if (clk)
1383		attrcount++;
1384
1385	indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
1386						   sizeof(indio_dev->chan_attr_group.attrs[0]),
1387						   GFP_KERNEL);
1388	if (indio_dev->chan_attr_group.attrs == NULL) {
1389		ret = -ENOMEM;
1390		goto error_clear_attrs;
1391	}
1392	/* Copy across original attributes */
1393	if (indio_dev->info->attrs)
1394		memcpy(indio_dev->chan_attr_group.attrs,
1395		       indio_dev->info->attrs->attrs,
1396		       sizeof(indio_dev->chan_attr_group.attrs[0])
1397		       *attrcount_orig);
1398	attrn = attrcount_orig;
1399	/* Add all elements from the list. */
1400	list_for_each_entry(p, &indio_dev->channel_attr_list, l)
1401		indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1402	if (indio_dev->name)
1403		indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1404	if (clk)
1405		indio_dev->chan_attr_group.attrs[attrn++] = clk;
1406
1407	indio_dev->groups[indio_dev->groupcounter++] =
1408		&indio_dev->chan_attr_group;
1409
1410	return 0;
1411
1412error_clear_attrs:
1413	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1414
1415	return ret;
1416}
1417
1418static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1419{
1420
1421	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1422	kfree(indio_dev->chan_attr_group.attrs);
1423	indio_dev->chan_attr_group.attrs = NULL;
1424}
1425
1426static void iio_dev_release(struct device *device)
1427{
1428	struct iio_dev *indio_dev = dev_to_iio_dev(device);
1429	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1430		iio_device_unregister_trigger_consumer(indio_dev);
1431	iio_device_unregister_eventset(indio_dev);
1432	iio_device_unregister_sysfs(indio_dev);
1433
1434	iio_buffer_put(indio_dev->buffer);
1435
1436	ida_simple_remove(&iio_ida, indio_dev->id);
1437	kfree(indio_dev);
1438}
1439
1440struct device_type iio_device_type = {
1441	.name = "iio_device",
1442	.release = iio_dev_release,
1443};
1444
1445/**
1446 * iio_device_alloc() - allocate an iio_dev from a driver
1447 * @sizeof_priv:	Space to allocate for private structure.
1448 **/
1449struct iio_dev *iio_device_alloc(int sizeof_priv)
1450{
1451	struct iio_dev *dev;
1452	size_t alloc_size;
1453
1454	alloc_size = sizeof(struct iio_dev);
1455	if (sizeof_priv) {
1456		alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1457		alloc_size += sizeof_priv;
1458	}
1459	/* ensure 32-byte alignment of whole construct ? */
1460	alloc_size += IIO_ALIGN - 1;
1461
1462	dev = kzalloc(alloc_size, GFP_KERNEL);
1463
1464	if (dev) {
1465		dev->dev.groups = dev->groups;
1466		dev->dev.type = &iio_device_type;
1467		dev->dev.bus = &iio_bus_type;
1468		device_initialize(&dev->dev);
1469		dev_set_drvdata(&dev->dev, (void *)dev);
1470		mutex_init(&dev->mlock);
1471		mutex_init(&dev->info_exist_lock);
1472		INIT_LIST_HEAD(&dev->channel_attr_list);
1473
1474		dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1475		if (dev->id < 0) {
1476			/* cannot use a dev_err as the name isn't available */
1477			pr_err("failed to get device id\n");
1478			kfree(dev);
1479			return NULL;
1480		}
1481		dev_set_name(&dev->dev, "iio:device%d", dev->id);
1482		INIT_LIST_HEAD(&dev->buffer_list);
1483	}
1484
1485	return dev;
1486}
1487EXPORT_SYMBOL(iio_device_alloc);
1488
1489/**
1490 * iio_device_free() - free an iio_dev from a driver
1491 * @dev:		the iio_dev associated with the device
1492 **/
1493void iio_device_free(struct iio_dev *dev)
1494{
1495	if (dev)
1496		put_device(&dev->dev);
1497}
1498EXPORT_SYMBOL(iio_device_free);
1499
1500static void devm_iio_device_release(struct device *dev, void *res)
1501{
1502	iio_device_free(*(struct iio_dev **)res);
1503}
1504
1505int devm_iio_device_match(struct device *dev, void *res, void *data)
1506{
1507	struct iio_dev **r = res;
1508	if (!r || !*r) {
1509		WARN_ON(!r || !*r);
1510		return 0;
1511	}
1512	return *r == data;
1513}
1514EXPORT_SYMBOL_GPL(devm_iio_device_match);
1515
1516/**
1517 * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1518 * @dev:		Device to allocate iio_dev for
1519 * @sizeof_priv:	Space to allocate for private structure.
1520 *
1521 * Managed iio_device_alloc. iio_dev allocated with this function is
1522 * automatically freed on driver detach.
1523 *
1524 * If an iio_dev allocated with this function needs to be freed separately,
1525 * devm_iio_device_free() must be used.
1526 *
1527 * RETURNS:
1528 * Pointer to allocated iio_dev on success, NULL on failure.
1529 */
1530struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1531{
1532	struct iio_dev **ptr, *iio_dev;
1533
1534	ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1535			   GFP_KERNEL);
1536	if (!ptr)
1537		return NULL;
1538
1539	iio_dev = iio_device_alloc(sizeof_priv);
1540	if (iio_dev) {
1541		*ptr = iio_dev;
1542		devres_add(dev, ptr);
1543	} else {
1544		devres_free(ptr);
1545	}
1546
1547	return iio_dev;
1548}
1549EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1550
1551/**
1552 * devm_iio_device_free - Resource-managed iio_device_free()
1553 * @dev:		Device this iio_dev belongs to
1554 * @iio_dev:		the iio_dev associated with the device
1555 *
1556 * Free iio_dev allocated with devm_iio_device_alloc().
1557 */
1558void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1559{
1560	int rc;
1561
1562	rc = devres_release(dev, devm_iio_device_release,
1563			    devm_iio_device_match, iio_dev);
1564	WARN_ON(rc);
1565}
1566EXPORT_SYMBOL_GPL(devm_iio_device_free);
1567
1568/**
1569 * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1570 * @inode:	Inode structure for identifying the device in the file system
1571 * @filp:	File structure for iio device used to keep and later access
1572 *		private data
1573 *
1574 * Return: 0 on success or -EBUSY if the device is already opened
1575 **/
1576static int iio_chrdev_open(struct inode *inode, struct file *filp)
1577{
1578	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1579						struct iio_dev, chrdev);
1580
1581	if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1582		return -EBUSY;
1583
1584	iio_device_get(indio_dev);
1585
1586	filp->private_data = indio_dev;
1587
1588	return 0;
1589}
1590
1591/**
1592 * iio_chrdev_release() - chrdev file close buffer access and ioctls
1593 * @inode:	Inode structure pointer for the char device
1594 * @filp:	File structure pointer for the char device
1595 *
1596 * Return: 0 for successful release
1597 */
1598static int iio_chrdev_release(struct inode *inode, struct file *filp)
1599{
1600	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1601						struct iio_dev, chrdev);
1602	clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1603	iio_device_put(indio_dev);
1604
1605	return 0;
1606}
1607
1608/* Somewhat of a cross file organization violation - ioctls here are actually
1609 * event related */
1610static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1611{
1612	struct iio_dev *indio_dev = filp->private_data;
1613	int __user *ip = (int __user *)arg;
1614	int fd;
1615
1616	if (!indio_dev->info)
1617		return -ENODEV;
1618
1619	if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1620		fd = iio_event_getfd(indio_dev);
1621		if (fd < 0)
1622			return fd;
1623		if (copy_to_user(ip, &fd, sizeof(fd)))
1624			return -EFAULT;
1625		return 0;
1626	}
1627	return -EINVAL;
1628}
1629
1630static const struct file_operations iio_buffer_fileops = {
1631	.read = iio_buffer_read_first_n_outer_addr,
1632	.release = iio_chrdev_release,
1633	.open = iio_chrdev_open,
1634	.poll = iio_buffer_poll_addr,
1635	.owner = THIS_MODULE,
1636	.llseek = noop_llseek,
1637	.unlocked_ioctl = iio_ioctl,
1638	.compat_ioctl = iio_ioctl,
1639};
1640
1641static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1642{
1643	int i, j;
1644	const struct iio_chan_spec *channels = indio_dev->channels;
1645
1646	if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1647		return 0;
1648
1649	for (i = 0; i < indio_dev->num_channels - 1; i++) {
1650		if (channels[i].scan_index < 0)
1651			continue;
1652		for (j = i + 1; j < indio_dev->num_channels; j++)
1653			if (channels[i].scan_index == channels[j].scan_index) {
1654				dev_err(&indio_dev->dev,
1655					"Duplicate scan index %d\n",
1656					channels[i].scan_index);
1657				return -EINVAL;
1658			}
1659	}
1660
1661	return 0;
1662}
1663
1664static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1665
1666int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1667{
1668	int ret;
1669
1670	indio_dev->driver_module = this_mod;
1671	/* If the calling driver did not initialize of_node, do it here */
1672	if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1673		indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1674
1675	ret = iio_check_unique_scan_index(indio_dev);
1676	if (ret < 0)
1677		return ret;
1678
1679	/* configure elements for the chrdev */
1680	indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1681
1682	ret = iio_device_register_debugfs(indio_dev);
1683	if (ret) {
1684		dev_err(indio_dev->dev.parent,
1685			"Failed to register debugfs interfaces\n");
1686		return ret;
1687	}
1688
1689	ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1690	if (ret) {
1691		dev_err(indio_dev->dev.parent,
1692			"Failed to create buffer sysfs interfaces\n");
1693		goto error_unreg_debugfs;
1694	}
1695
1696	ret = iio_device_register_sysfs(indio_dev);
1697	if (ret) {
1698		dev_err(indio_dev->dev.parent,
1699			"Failed to register sysfs interfaces\n");
1700		goto error_buffer_free_sysfs;
1701	}
1702	ret = iio_device_register_eventset(indio_dev);
1703	if (ret) {
1704		dev_err(indio_dev->dev.parent,
1705			"Failed to register event set\n");
1706		goto error_free_sysfs;
1707	}
1708	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1709		iio_device_register_trigger_consumer(indio_dev);
1710
1711	if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1712		indio_dev->setup_ops == NULL)
1713		indio_dev->setup_ops = &noop_ring_setup_ops;
1714
1715	cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1716
1717	indio_dev->chrdev.owner = this_mod;
1718
1719	ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev);
1720	if (ret < 0)
1721		goto error_unreg_eventset;
1722
1723	return 0;
1724
1725error_unreg_eventset:
1726	iio_device_unregister_eventset(indio_dev);
1727error_free_sysfs:
1728	iio_device_unregister_sysfs(indio_dev);
1729error_buffer_free_sysfs:
1730	iio_buffer_free_sysfs_and_mask(indio_dev);
1731error_unreg_debugfs:
1732	iio_device_unregister_debugfs(indio_dev);
1733	return ret;
1734}
1735EXPORT_SYMBOL(__iio_device_register);
1736
1737/**
1738 * iio_device_unregister() - unregister a device from the IIO subsystem
1739 * @indio_dev:		Device structure representing the device.
1740 **/
1741void iio_device_unregister(struct iio_dev *indio_dev)
1742{
1743	mutex_lock(&indio_dev->info_exist_lock);
1744
1745	cdev_device_del(&indio_dev->chrdev, &indio_dev->dev);
1746
1747	iio_device_unregister_debugfs(indio_dev);
1748
1749	iio_disable_all_buffers(indio_dev);
1750
1751	indio_dev->info = NULL;
1752
1753	iio_device_wakeup_eventset(indio_dev);
1754	iio_buffer_wakeup_poll(indio_dev);
1755
1756	mutex_unlock(&indio_dev->info_exist_lock);
1757
1758	iio_buffer_free_sysfs_and_mask(indio_dev);
1759}
1760EXPORT_SYMBOL(iio_device_unregister);
1761
1762static void devm_iio_device_unreg(struct device *dev, void *res)
1763{
1764	iio_device_unregister(*(struct iio_dev **)res);
1765}
1766
1767int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
1768			       struct module *this_mod)
1769{
1770	struct iio_dev **ptr;
1771	int ret;
1772
1773	ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1774	if (!ptr)
1775		return -ENOMEM;
1776
1777	*ptr = indio_dev;
1778	ret = __iio_device_register(indio_dev, this_mod);
1779	if (!ret)
1780		devres_add(dev, ptr);
1781	else
1782		devres_free(ptr);
1783
1784	return ret;
1785}
1786EXPORT_SYMBOL_GPL(__devm_iio_device_register);
1787
1788/**
1789 * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1790 * @dev:	Device this iio_dev belongs to
1791 * @indio_dev:	the iio_dev associated with the device
1792 *
1793 * Unregister iio_dev registered with devm_iio_device_register().
1794 */
1795void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1796{
1797	int rc;
1798
1799	rc = devres_release(dev, devm_iio_device_unreg,
1800			    devm_iio_device_match, indio_dev);
1801	WARN_ON(rc);
1802}
1803EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1804
1805/**
1806 * iio_device_claim_direct_mode - Keep device in direct mode
1807 * @indio_dev:	the iio_dev associated with the device
1808 *
1809 * If the device is in direct mode it is guaranteed to stay
1810 * that way until iio_device_release_direct_mode() is called.
1811 *
1812 * Use with iio_device_release_direct_mode()
1813 *
1814 * Returns: 0 on success, -EBUSY on failure
1815 */
1816int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1817{
1818	mutex_lock(&indio_dev->mlock);
1819
1820	if (iio_buffer_enabled(indio_dev)) {
1821		mutex_unlock(&indio_dev->mlock);
1822		return -EBUSY;
1823	}
1824	return 0;
1825}
1826EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1827
1828/**
1829 * iio_device_release_direct_mode - releases claim on direct mode
1830 * @indio_dev:	the iio_dev associated with the device
1831 *
1832 * Release the claim. Device is no longer guaranteed to stay
1833 * in direct mode.
1834 *
1835 * Use with iio_device_claim_direct_mode()
1836 */
1837void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1838{
1839	mutex_unlock(&indio_dev->mlock);
1840}
1841EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1842
1843subsys_initcall(iio_init);
1844module_exit(iio_exit);
1845
1846MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1847MODULE_DESCRIPTION("Industrial I/O core");
1848MODULE_LICENSE("GPL");