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   1// SPDX-License-Identifier: GPL-2.0-only
   2/* The industrial I/O core
   3 *
   4 * Copyright (c) 2008 Jonathan Cameron
   5 *
   6 * Based on elements of hwmon and input subsystems.
   7 */
   8
   9#define pr_fmt(fmt) "iio-core: " fmt
  10
  11#include <linux/kernel.h>
  12#include <linux/module.h>
  13#include <linux/idr.h>
  14#include <linux/kdev_t.h>
  15#include <linux/err.h>
  16#include <linux/device.h>
  17#include <linux/fs.h>
  18#include <linux/poll.h>
  19#include <linux/property.h>
  20#include <linux/sched.h>
  21#include <linux/wait.h>
  22#include <linux/cdev.h>
  23#include <linux/slab.h>
  24#include <linux/anon_inodes.h>
  25#include <linux/debugfs.h>
  26#include <linux/mutex.h>
  27#include <linux/iio/iio.h>
  28#include "iio_core.h"
  29#include "iio_core_trigger.h"
  30#include <linux/iio/sysfs.h>
  31#include <linux/iio/events.h>
  32#include <linux/iio/buffer.h>
  33#include <linux/iio/buffer_impl.h>
  34
  35/* IDA to assign each registered device a unique id */
  36static DEFINE_IDA(iio_ida);
  37
  38static dev_t iio_devt;
  39
  40#define IIO_DEV_MAX 256
  41struct bus_type iio_bus_type = {
  42	.name = "iio",
  43};
  44EXPORT_SYMBOL(iio_bus_type);
  45
  46static struct dentry *iio_debugfs_dentry;
  47
  48static const char * const iio_direction[] = {
  49	[0] = "in",
  50	[1] = "out",
  51};
  52
  53static const char * const iio_chan_type_name_spec[] = {
  54	[IIO_VOLTAGE] = "voltage",
  55	[IIO_CURRENT] = "current",
  56	[IIO_POWER] = "power",
  57	[IIO_ACCEL] = "accel",
  58	[IIO_ANGL_VEL] = "anglvel",
  59	[IIO_MAGN] = "magn",
  60	[IIO_LIGHT] = "illuminance",
  61	[IIO_INTENSITY] = "intensity",
  62	[IIO_PROXIMITY] = "proximity",
  63	[IIO_TEMP] = "temp",
  64	[IIO_INCLI] = "incli",
  65	[IIO_ROT] = "rot",
  66	[IIO_ANGL] = "angl",
  67	[IIO_TIMESTAMP] = "timestamp",
  68	[IIO_CAPACITANCE] = "capacitance",
  69	[IIO_ALTVOLTAGE] = "altvoltage",
  70	[IIO_CCT] = "cct",
  71	[IIO_PRESSURE] = "pressure",
  72	[IIO_HUMIDITYRELATIVE] = "humidityrelative",
  73	[IIO_ACTIVITY] = "activity",
  74	[IIO_STEPS] = "steps",
  75	[IIO_ENERGY] = "energy",
  76	[IIO_DISTANCE] = "distance",
  77	[IIO_VELOCITY] = "velocity",
  78	[IIO_CONCENTRATION] = "concentration",
  79	[IIO_RESISTANCE] = "resistance",
  80	[IIO_PH] = "ph",
  81	[IIO_UVINDEX] = "uvindex",
  82	[IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
  83	[IIO_COUNT] = "count",
  84	[IIO_INDEX] = "index",
  85	[IIO_GRAVITY]  = "gravity",
  86	[IIO_POSITIONRELATIVE]  = "positionrelative",
  87	[IIO_PHASE] = "phase",
  88	[IIO_MASSCONCENTRATION] = "massconcentration",
  89};
  90
  91static const char * const iio_modifier_names[] = {
  92	[IIO_MOD_X] = "x",
  93	[IIO_MOD_Y] = "y",
  94	[IIO_MOD_Z] = "z",
  95	[IIO_MOD_X_AND_Y] = "x&y",
  96	[IIO_MOD_X_AND_Z] = "x&z",
  97	[IIO_MOD_Y_AND_Z] = "y&z",
  98	[IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
  99	[IIO_MOD_X_OR_Y] = "x|y",
 100	[IIO_MOD_X_OR_Z] = "x|z",
 101	[IIO_MOD_Y_OR_Z] = "y|z",
 102	[IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
 103	[IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
 104	[IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
 105	[IIO_MOD_LIGHT_BOTH] = "both",
 106	[IIO_MOD_LIGHT_IR] = "ir",
 107	[IIO_MOD_LIGHT_CLEAR] = "clear",
 108	[IIO_MOD_LIGHT_RED] = "red",
 109	[IIO_MOD_LIGHT_GREEN] = "green",
 110	[IIO_MOD_LIGHT_BLUE] = "blue",
 111	[IIO_MOD_LIGHT_UV] = "uv",
 112	[IIO_MOD_LIGHT_DUV] = "duv",
 113	[IIO_MOD_QUATERNION] = "quaternion",
 114	[IIO_MOD_TEMP_AMBIENT] = "ambient",
 115	[IIO_MOD_TEMP_OBJECT] = "object",
 116	[IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
 117	[IIO_MOD_NORTH_TRUE] = "from_north_true",
 118	[IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
 119	[IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
 120	[IIO_MOD_RUNNING] = "running",
 121	[IIO_MOD_JOGGING] = "jogging",
 122	[IIO_MOD_WALKING] = "walking",
 123	[IIO_MOD_STILL] = "still",
 124	[IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
 125	[IIO_MOD_I] = "i",
 126	[IIO_MOD_Q] = "q",
 127	[IIO_MOD_CO2] = "co2",
 128	[IIO_MOD_VOC] = "voc",
 129	[IIO_MOD_PM1] = "pm1",
 130	[IIO_MOD_PM2P5] = "pm2p5",
 131	[IIO_MOD_PM4] = "pm4",
 132	[IIO_MOD_PM10] = "pm10",
 133};
 134
 135/* relies on pairs of these shared then separate */
 136static const char * const iio_chan_info_postfix[] = {
 137	[IIO_CHAN_INFO_RAW] = "raw",
 138	[IIO_CHAN_INFO_PROCESSED] = "input",
 139	[IIO_CHAN_INFO_SCALE] = "scale",
 140	[IIO_CHAN_INFO_OFFSET] = "offset",
 141	[IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
 142	[IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
 143	[IIO_CHAN_INFO_PEAK] = "peak_raw",
 144	[IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
 145	[IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
 146	[IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
 147	[IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
 148	= "filter_low_pass_3db_frequency",
 149	[IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
 150	= "filter_high_pass_3db_frequency",
 151	[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
 152	[IIO_CHAN_INFO_FREQUENCY] = "frequency",
 153	[IIO_CHAN_INFO_PHASE] = "phase",
 154	[IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 155	[IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
 156	[IIO_CHAN_INFO_INT_TIME] = "integration_time",
 157	[IIO_CHAN_INFO_ENABLE] = "en",
 158	[IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
 159	[IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
 160	[IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
 161	[IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
 162	[IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
 163	[IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
 164};
 165
 166/**
 167 * iio_find_channel_from_si() - get channel from its scan index
 168 * @indio_dev:		device
 169 * @si:			scan index to match
 170 */
 171const struct iio_chan_spec
 172*iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
 173{
 174	int i;
 175
 176	for (i = 0; i < indio_dev->num_channels; i++)
 177		if (indio_dev->channels[i].scan_index == si)
 178			return &indio_dev->channels[i];
 179	return NULL;
 180}
 181
 182/* This turns up an awful lot */
 183ssize_t iio_read_const_attr(struct device *dev,
 184			    struct device_attribute *attr,
 185			    char *buf)
 186{
 187	return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 188}
 189EXPORT_SYMBOL(iio_read_const_attr);
 190
 191static int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
 192{
 193	int ret;
 194	const struct iio_event_interface *ev_int = indio_dev->event_interface;
 195
 196	ret = mutex_lock_interruptible(&indio_dev->mlock);
 197	if (ret)
 198		return ret;
 199	if ((ev_int && iio_event_enabled(ev_int)) ||
 200	    iio_buffer_enabled(indio_dev)) {
 201		mutex_unlock(&indio_dev->mlock);
 202		return -EBUSY;
 203	}
 204	indio_dev->clock_id = clock_id;
 205	mutex_unlock(&indio_dev->mlock);
 206
 207	return 0;
 208}
 209
 210/**
 211 * iio_get_time_ns() - utility function to get a time stamp for events etc
 212 * @indio_dev: device
 213 */
 214s64 iio_get_time_ns(const struct iio_dev *indio_dev)
 215{
 216	struct timespec64 tp;
 217
 218	switch (iio_device_get_clock(indio_dev)) {
 219	case CLOCK_REALTIME:
 220		return ktime_get_real_ns();
 221	case CLOCK_MONOTONIC:
 222		return ktime_get_ns();
 223	case CLOCK_MONOTONIC_RAW:
 224		return ktime_get_raw_ns();
 225	case CLOCK_REALTIME_COARSE:
 226		return ktime_to_ns(ktime_get_coarse_real());
 227	case CLOCK_MONOTONIC_COARSE:
 228		ktime_get_coarse_ts64(&tp);
 229		return timespec64_to_ns(&tp);
 230	case CLOCK_BOOTTIME:
 231		return ktime_get_boottime_ns();
 232	case CLOCK_TAI:
 233		return ktime_get_clocktai_ns();
 234	default:
 235		BUG();
 236	}
 237}
 238EXPORT_SYMBOL(iio_get_time_ns);
 239
 240/**
 241 * iio_get_time_res() - utility function to get time stamp clock resolution in
 242 *                      nano seconds.
 243 * @indio_dev: device
 244 */
 245unsigned int iio_get_time_res(const struct iio_dev *indio_dev)
 246{
 247	switch (iio_device_get_clock(indio_dev)) {
 248	case CLOCK_REALTIME:
 249	case CLOCK_MONOTONIC:
 250	case CLOCK_MONOTONIC_RAW:
 251	case CLOCK_BOOTTIME:
 252	case CLOCK_TAI:
 253		return hrtimer_resolution;
 254	case CLOCK_REALTIME_COARSE:
 255	case CLOCK_MONOTONIC_COARSE:
 256		return LOW_RES_NSEC;
 257	default:
 258		BUG();
 259	}
 260}
 261EXPORT_SYMBOL(iio_get_time_res);
 262
 263static int __init iio_init(void)
 264{
 265	int ret;
 266
 267	/* Register sysfs bus */
 268	ret  = bus_register(&iio_bus_type);
 269	if (ret < 0) {
 270		pr_err("could not register bus type\n");
 271		goto error_nothing;
 272	}
 273
 274	ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 275	if (ret < 0) {
 276		pr_err("failed to allocate char dev region\n");
 277		goto error_unregister_bus_type;
 278	}
 279
 280	iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 281
 282	return 0;
 283
 284error_unregister_bus_type:
 285	bus_unregister(&iio_bus_type);
 286error_nothing:
 287	return ret;
 288}
 289
 290static void __exit iio_exit(void)
 291{
 292	if (iio_devt)
 293		unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 294	bus_unregister(&iio_bus_type);
 295	debugfs_remove(iio_debugfs_dentry);
 296}
 297
 298#if defined(CONFIG_DEBUG_FS)
 299static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 300			      size_t count, loff_t *ppos)
 301{
 302	struct iio_dev *indio_dev = file->private_data;
 303	char buf[20];
 304	unsigned val = 0;
 305	ssize_t len;
 306	int ret;
 307
 308	ret = indio_dev->info->debugfs_reg_access(indio_dev,
 309						  indio_dev->cached_reg_addr,
 310						  0, &val);
 311	if (ret) {
 312		dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 313		return ret;
 314	}
 315
 316	len = snprintf(buf, sizeof(buf), "0x%X\n", val);
 317
 318	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
 319}
 320
 321static ssize_t iio_debugfs_write_reg(struct file *file,
 322		     const char __user *userbuf, size_t count, loff_t *ppos)
 323{
 324	struct iio_dev *indio_dev = file->private_data;
 325	unsigned reg, val;
 326	char buf[80];
 327	int ret;
 328
 329	count = min_t(size_t, count, (sizeof(buf)-1));
 330	if (copy_from_user(buf, userbuf, count))
 331		return -EFAULT;
 332
 333	buf[count] = 0;
 334
 335	ret = sscanf(buf, "%i %i", &reg, &val);
 336
 337	switch (ret) {
 338	case 1:
 339		indio_dev->cached_reg_addr = reg;
 340		break;
 341	case 2:
 342		indio_dev->cached_reg_addr = reg;
 343		ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 344							  val, NULL);
 345		if (ret) {
 346			dev_err(indio_dev->dev.parent, "%s: write failed\n",
 347				__func__);
 348			return ret;
 349		}
 350		break;
 351	default:
 352		return -EINVAL;
 353	}
 354
 355	return count;
 356}
 357
 358static const struct file_operations iio_debugfs_reg_fops = {
 359	.open = simple_open,
 360	.read = iio_debugfs_read_reg,
 361	.write = iio_debugfs_write_reg,
 362};
 363
 364static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 365{
 366	debugfs_remove_recursive(indio_dev->debugfs_dentry);
 367}
 368
 369static void iio_device_register_debugfs(struct iio_dev *indio_dev)
 370{
 371	if (indio_dev->info->debugfs_reg_access == NULL)
 372		return;
 373
 374	if (!iio_debugfs_dentry)
 375		return;
 376
 377	indio_dev->debugfs_dentry =
 378		debugfs_create_dir(dev_name(&indio_dev->dev),
 379				   iio_debugfs_dentry);
 380
 381	debugfs_create_file("direct_reg_access", 0644,
 382			    indio_dev->debugfs_dentry, indio_dev,
 383			    &iio_debugfs_reg_fops);
 384}
 385#else
 386static void iio_device_register_debugfs(struct iio_dev *indio_dev)
 387{
 388}
 389
 390static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 391{
 392}
 393#endif /* CONFIG_DEBUG_FS */
 394
 395static ssize_t iio_read_channel_ext_info(struct device *dev,
 396				     struct device_attribute *attr,
 397				     char *buf)
 398{
 399	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 400	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 401	const struct iio_chan_spec_ext_info *ext_info;
 402
 403	ext_info = &this_attr->c->ext_info[this_attr->address];
 404
 405	return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
 406}
 407
 408static ssize_t iio_write_channel_ext_info(struct device *dev,
 409				     struct device_attribute *attr,
 410				     const char *buf,
 411					 size_t len)
 412{
 413	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 414	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 415	const struct iio_chan_spec_ext_info *ext_info;
 416
 417	ext_info = &this_attr->c->ext_info[this_attr->address];
 418
 419	return ext_info->write(indio_dev, ext_info->private,
 420			       this_attr->c, buf, len);
 421}
 422
 423ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 424	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 425{
 426	const struct iio_enum *e = (const struct iio_enum *)priv;
 427	unsigned int i;
 428	size_t len = 0;
 429
 430	if (!e->num_items)
 431		return 0;
 432
 433	for (i = 0; i < e->num_items; ++i)
 434		len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
 435
 436	/* replace last space with a newline */
 437	buf[len - 1] = '\n';
 438
 439	return len;
 440}
 441EXPORT_SYMBOL_GPL(iio_enum_available_read);
 442
 443ssize_t iio_enum_read(struct iio_dev *indio_dev,
 444	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 445{
 446	const struct iio_enum *e = (const struct iio_enum *)priv;
 447	int i;
 448
 449	if (!e->get)
 450		return -EINVAL;
 451
 452	i = e->get(indio_dev, chan);
 453	if (i < 0)
 454		return i;
 455	else if (i >= e->num_items)
 456		return -EINVAL;
 457
 458	return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
 459}
 460EXPORT_SYMBOL_GPL(iio_enum_read);
 461
 462ssize_t iio_enum_write(struct iio_dev *indio_dev,
 463	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 464	size_t len)
 465{
 466	const struct iio_enum *e = (const struct iio_enum *)priv;
 467	int ret;
 468
 469	if (!e->set)
 470		return -EINVAL;
 471
 472	ret = __sysfs_match_string(e->items, e->num_items, buf);
 473	if (ret < 0)
 474		return ret;
 475
 476	ret = e->set(indio_dev, chan, ret);
 477	return ret ? ret : len;
 478}
 479EXPORT_SYMBOL_GPL(iio_enum_write);
 480
 481static const struct iio_mount_matrix iio_mount_idmatrix = {
 482	.rotation = {
 483		"1", "0", "0",
 484		"0", "1", "0",
 485		"0", "0", "1"
 486	}
 487};
 488
 489static int iio_setup_mount_idmatrix(const struct device *dev,
 490				    struct iio_mount_matrix *matrix)
 491{
 492	*matrix = iio_mount_idmatrix;
 493	dev_info(dev, "mounting matrix not found: using identity...\n");
 494	return 0;
 495}
 496
 497ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
 498			      const struct iio_chan_spec *chan, char *buf)
 499{
 500	const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
 501					      priv)(indio_dev, chan);
 502
 503	if (IS_ERR(mtx))
 504		return PTR_ERR(mtx);
 505
 506	if (!mtx)
 507		mtx = &iio_mount_idmatrix;
 508
 509	return snprintf(buf, PAGE_SIZE, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
 510			mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
 511			mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
 512			mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
 513}
 514EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
 515
 516/**
 517 * iio_read_mount_matrix() - retrieve iio device mounting matrix from
 518 *                           device "mount-matrix" property
 519 * @dev:	device the mounting matrix property is assigned to
 520 * @propname:	device specific mounting matrix property name
 521 * @matrix:	where to store retrieved matrix
 522 *
 523 * If device is assigned no mounting matrix property, a default 3x3 identity
 524 * matrix will be filled in.
 525 *
 526 * Return: 0 if success, or a negative error code on failure.
 527 */
 528int iio_read_mount_matrix(struct device *dev, const char *propname,
 529			  struct iio_mount_matrix *matrix)
 530{
 531	size_t len = ARRAY_SIZE(iio_mount_idmatrix.rotation);
 532	int err;
 533
 534	err = device_property_read_string_array(dev, propname,
 535						matrix->rotation, len);
 536	if (err == len)
 537		return 0;
 538
 539	if (err >= 0)
 540		/* Invalid number of matrix entries. */
 541		return -EINVAL;
 542
 543	if (err != -EINVAL)
 544		/* Invalid matrix declaration format. */
 545		return err;
 546
 547	/* Matrix was not declared at all: fallback to identity. */
 548	return iio_setup_mount_idmatrix(dev, matrix);
 549}
 550EXPORT_SYMBOL(iio_read_mount_matrix);
 551
 552static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
 553				  int size, const int *vals)
 554{
 555	unsigned long long tmp;
 556	int tmp0, tmp1;
 557	bool scale_db = false;
 558
 559	switch (type) {
 560	case IIO_VAL_INT:
 561		return snprintf(buf, len, "%d", vals[0]);
 562	case IIO_VAL_INT_PLUS_MICRO_DB:
 563		scale_db = true;
 564		/* fall through */
 565	case IIO_VAL_INT_PLUS_MICRO:
 566		if (vals[1] < 0)
 567			return snprintf(buf, len, "-%d.%06u%s", abs(vals[0]),
 568					-vals[1], scale_db ? " dB" : "");
 569		else
 570			return snprintf(buf, len, "%d.%06u%s", vals[0], vals[1],
 571					scale_db ? " dB" : "");
 572	case IIO_VAL_INT_PLUS_NANO:
 573		if (vals[1] < 0)
 574			return snprintf(buf, len, "-%d.%09u", abs(vals[0]),
 575					-vals[1]);
 576		else
 577			return snprintf(buf, len, "%d.%09u", vals[0], vals[1]);
 578	case IIO_VAL_FRACTIONAL:
 579		tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
 580		tmp1 = vals[1];
 581		tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1);
 582		return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 583	case IIO_VAL_FRACTIONAL_LOG2:
 584		tmp = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
 585		tmp0 = (int)div_s64_rem(tmp, 1000000000LL, &tmp1);
 586		return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 587	case IIO_VAL_INT_MULTIPLE:
 588	{
 589		int i;
 590		int l = 0;
 591
 592		for (i = 0; i < size; ++i) {
 593			l += snprintf(&buf[l], len - l, "%d ", vals[i]);
 594			if (l >= len)
 595				break;
 596		}
 597		return l;
 598	}
 599	default:
 600		return 0;
 601	}
 602}
 603
 604/**
 605 * iio_format_value() - Formats a IIO value into its string representation
 606 * @buf:	The buffer to which the formatted value gets written
 607 *		which is assumed to be big enough (i.e. PAGE_SIZE).
 608 * @type:	One of the IIO_VAL_* constants. This decides how the val
 609 *		and val2 parameters are formatted.
 610 * @size:	Number of IIO value entries contained in vals
 611 * @vals:	Pointer to the values, exact meaning depends on the
 612 *		type parameter.
 613 *
 614 * Return: 0 by default, a negative number on failure or the
 615 *	   total number of characters written for a type that belongs
 616 *	   to the IIO_VAL_* constant.
 617 */
 618ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
 619{
 620	ssize_t len;
 621
 622	len = __iio_format_value(buf, PAGE_SIZE, type, size, vals);
 623	if (len >= PAGE_SIZE - 1)
 624		return -EFBIG;
 625
 626	return len + sprintf(buf + len, "\n");
 627}
 628EXPORT_SYMBOL_GPL(iio_format_value);
 629
 630static ssize_t iio_read_channel_info(struct device *dev,
 631				     struct device_attribute *attr,
 632				     char *buf)
 633{
 634	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 635	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 636	int vals[INDIO_MAX_RAW_ELEMENTS];
 637	int ret;
 638	int val_len = 2;
 639
 640	if (indio_dev->info->read_raw_multi)
 641		ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
 642							INDIO_MAX_RAW_ELEMENTS,
 643							vals, &val_len,
 644							this_attr->address);
 645	else
 646		ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 647				    &vals[0], &vals[1], this_attr->address);
 648
 649	if (ret < 0)
 650		return ret;
 651
 652	return iio_format_value(buf, ret, val_len, vals);
 653}
 654
 655static ssize_t iio_format_avail_list(char *buf, const int *vals,
 656				     int type, int length)
 657{
 658	int i;
 659	ssize_t len = 0;
 660
 661	switch (type) {
 662	case IIO_VAL_INT:
 663		for (i = 0; i < length; i++) {
 664			len += __iio_format_value(buf + len, PAGE_SIZE - len,
 665						  type, 1, &vals[i]);
 666			if (len >= PAGE_SIZE)
 667				return -EFBIG;
 668			if (i < length - 1)
 669				len += snprintf(buf + len, PAGE_SIZE - len,
 670						" ");
 671			else
 672				len += snprintf(buf + len, PAGE_SIZE - len,
 673						"\n");
 674			if (len >= PAGE_SIZE)
 675				return -EFBIG;
 676		}
 677		break;
 678	default:
 679		for (i = 0; i < length / 2; i++) {
 680			len += __iio_format_value(buf + len, PAGE_SIZE - len,
 681						  type, 2, &vals[i * 2]);
 682			if (len >= PAGE_SIZE)
 683				return -EFBIG;
 684			if (i < length / 2 - 1)
 685				len += snprintf(buf + len, PAGE_SIZE - len,
 686						" ");
 687			else
 688				len += snprintf(buf + len, PAGE_SIZE - len,
 689						"\n");
 690			if (len >= PAGE_SIZE)
 691				return -EFBIG;
 692		}
 693	}
 694
 695	return len;
 696}
 697
 698static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
 699{
 700	int i;
 701	ssize_t len;
 702
 703	len = snprintf(buf, PAGE_SIZE, "[");
 704	switch (type) {
 705	case IIO_VAL_INT:
 706		for (i = 0; i < 3; i++) {
 707			len += __iio_format_value(buf + len, PAGE_SIZE - len,
 708						  type, 1, &vals[i]);
 709			if (len >= PAGE_SIZE)
 710				return -EFBIG;
 711			if (i < 2)
 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		break;
 721	default:
 722		for (i = 0; i < 3; i++) {
 723			len += __iio_format_value(buf + len, PAGE_SIZE - len,
 724						  type, 2, &vals[i * 2]);
 725			if (len >= PAGE_SIZE)
 726				return -EFBIG;
 727			if (i < 2)
 728				len += snprintf(buf + len, PAGE_SIZE - len,
 729						" ");
 730			else
 731				len += snprintf(buf + len, PAGE_SIZE - len,
 732						"]\n");
 733			if (len >= PAGE_SIZE)
 734				return -EFBIG;
 735		}
 736	}
 737
 738	return len;
 739}
 740
 741static ssize_t iio_read_channel_info_avail(struct device *dev,
 742					   struct device_attribute *attr,
 743					   char *buf)
 744{
 745	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 746	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 747	const int *vals;
 748	int ret;
 749	int length;
 750	int type;
 751
 752	ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
 753					  &vals, &type, &length,
 754					  this_attr->address);
 755
 756	if (ret < 0)
 757		return ret;
 758	switch (ret) {
 759	case IIO_AVAIL_LIST:
 760		return iio_format_avail_list(buf, vals, type, length);
 761	case IIO_AVAIL_RANGE:
 762		return iio_format_avail_range(buf, vals, type);
 763	default:
 764		return -EINVAL;
 765	}
 766}
 767
 768/**
 769 * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 770 * @str: The string to parse
 771 * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 772 * @integer: The integer part of the number
 773 * @fract: The fractional part of the number
 774 *
 775 * Returns 0 on success, or a negative error code if the string could not be
 776 * parsed.
 777 */
 778int iio_str_to_fixpoint(const char *str, int fract_mult,
 779	int *integer, int *fract)
 780{
 781	int i = 0, f = 0;
 782	bool integer_part = true, negative = false;
 783
 784	if (fract_mult == 0) {
 785		*fract = 0;
 786
 787		return kstrtoint(str, 0, integer);
 788	}
 789
 790	if (str[0] == '-') {
 791		negative = true;
 792		str++;
 793	} else if (str[0] == '+') {
 794		str++;
 795	}
 796
 797	while (*str) {
 798		if ('0' <= *str && *str <= '9') {
 799			if (integer_part) {
 800				i = i * 10 + *str - '0';
 801			} else {
 802				f += fract_mult * (*str - '0');
 803				fract_mult /= 10;
 804			}
 805		} else if (*str == '\n') {
 806			if (*(str + 1) == '\0')
 807				break;
 808			else
 809				return -EINVAL;
 810		} else if (*str == '.' && integer_part) {
 811			integer_part = false;
 812		} else {
 813			return -EINVAL;
 814		}
 815		str++;
 816	}
 817
 818	if (negative) {
 819		if (i)
 820			i = -i;
 821		else
 822			f = -f;
 823	}
 824
 825	*integer = i;
 826	*fract = f;
 827
 828	return 0;
 829}
 830EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 831
 832static ssize_t iio_write_channel_info(struct device *dev,
 833				      struct device_attribute *attr,
 834				      const char *buf,
 835				      size_t len)
 836{
 837	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 838	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 839	int ret, fract_mult = 100000;
 840	int integer, fract;
 841
 842	/* Assumes decimal - precision based on number of digits */
 843	if (!indio_dev->info->write_raw)
 844		return -EINVAL;
 845
 846	if (indio_dev->info->write_raw_get_fmt)
 847		switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 848			this_attr->c, this_attr->address)) {
 849		case IIO_VAL_INT:
 850			fract_mult = 0;
 851			break;
 852		case IIO_VAL_INT_PLUS_MICRO:
 853			fract_mult = 100000;
 854			break;
 855		case IIO_VAL_INT_PLUS_NANO:
 856			fract_mult = 100000000;
 857			break;
 858		default:
 859			return -EINVAL;
 860		}
 861
 862	ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
 863	if (ret)
 864		return ret;
 865
 866	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 867					 integer, fract, this_attr->address);
 868	if (ret)
 869		return ret;
 870
 871	return len;
 872}
 873
 874static
 875int __iio_device_attr_init(struct device_attribute *dev_attr,
 876			   const char *postfix,
 877			   struct iio_chan_spec const *chan,
 878			   ssize_t (*readfunc)(struct device *dev,
 879					       struct device_attribute *attr,
 880					       char *buf),
 881			   ssize_t (*writefunc)(struct device *dev,
 882						struct device_attribute *attr,
 883						const char *buf,
 884						size_t len),
 885			   enum iio_shared_by shared_by)
 886{
 887	int ret = 0;
 888	char *name = NULL;
 889	char *full_postfix;
 890	sysfs_attr_init(&dev_attr->attr);
 891
 892	/* Build up postfix of <extend_name>_<modifier>_postfix */
 893	if (chan->modified && (shared_by == IIO_SEPARATE)) {
 894		if (chan->extend_name)
 895			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 896						 iio_modifier_names[chan
 897								    ->channel2],
 898						 chan->extend_name,
 899						 postfix);
 900		else
 901			full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 902						 iio_modifier_names[chan
 903								    ->channel2],
 904						 postfix);
 905	} else {
 906		if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
 907			full_postfix = kstrdup(postfix, GFP_KERNEL);
 908		else
 909			full_postfix = kasprintf(GFP_KERNEL,
 910						 "%s_%s",
 911						 chan->extend_name,
 912						 postfix);
 913	}
 914	if (full_postfix == NULL)
 915		return -ENOMEM;
 916
 917	if (chan->differential) { /* Differential can not have modifier */
 918		switch (shared_by) {
 919		case IIO_SHARED_BY_ALL:
 920			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 921			break;
 922		case IIO_SHARED_BY_DIR:
 923			name = kasprintf(GFP_KERNEL, "%s_%s",
 924						iio_direction[chan->output],
 925						full_postfix);
 926			break;
 927		case IIO_SHARED_BY_TYPE:
 928			name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 929					    iio_direction[chan->output],
 930					    iio_chan_type_name_spec[chan->type],
 931					    iio_chan_type_name_spec[chan->type],
 932					    full_postfix);
 933			break;
 934		case IIO_SEPARATE:
 935			if (!chan->indexed) {
 936				WARN(1, "Differential channels must be indexed\n");
 937				ret = -EINVAL;
 938				goto error_free_full_postfix;
 939			}
 940			name = kasprintf(GFP_KERNEL,
 941					    "%s_%s%d-%s%d_%s",
 942					    iio_direction[chan->output],
 943					    iio_chan_type_name_spec[chan->type],
 944					    chan->channel,
 945					    iio_chan_type_name_spec[chan->type],
 946					    chan->channel2,
 947					    full_postfix);
 948			break;
 949		}
 950	} else { /* Single ended */
 951		switch (shared_by) {
 952		case IIO_SHARED_BY_ALL:
 953			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 954			break;
 955		case IIO_SHARED_BY_DIR:
 956			name = kasprintf(GFP_KERNEL, "%s_%s",
 957						iio_direction[chan->output],
 958						full_postfix);
 959			break;
 960		case IIO_SHARED_BY_TYPE:
 961			name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 962					    iio_direction[chan->output],
 963					    iio_chan_type_name_spec[chan->type],
 964					    full_postfix);
 965			break;
 966
 967		case IIO_SEPARATE:
 968			if (chan->indexed)
 969				name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 970						    iio_direction[chan->output],
 971						    iio_chan_type_name_spec[chan->type],
 972						    chan->channel,
 973						    full_postfix);
 974			else
 975				name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 976						    iio_direction[chan->output],
 977						    iio_chan_type_name_spec[chan->type],
 978						    full_postfix);
 979			break;
 980		}
 981	}
 982	if (name == NULL) {
 983		ret = -ENOMEM;
 984		goto error_free_full_postfix;
 985	}
 986	dev_attr->attr.name = name;
 987
 988	if (readfunc) {
 989		dev_attr->attr.mode |= S_IRUGO;
 990		dev_attr->show = readfunc;
 991	}
 992
 993	if (writefunc) {
 994		dev_attr->attr.mode |= S_IWUSR;
 995		dev_attr->store = writefunc;
 996	}
 997
 998error_free_full_postfix:
 999	kfree(full_postfix);
1000
1001	return ret;
1002}
1003
1004static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1005{
1006	kfree(dev_attr->attr.name);
1007}
1008
1009int __iio_add_chan_devattr(const char *postfix,
1010			   struct iio_chan_spec const *chan,
1011			   ssize_t (*readfunc)(struct device *dev,
1012					       struct device_attribute *attr,
1013					       char *buf),
1014			   ssize_t (*writefunc)(struct device *dev,
1015						struct device_attribute *attr,
1016						const char *buf,
1017						size_t len),
1018			   u64 mask,
1019			   enum iio_shared_by shared_by,
1020			   struct device *dev,
1021			   struct list_head *attr_list)
1022{
1023	int ret;
1024	struct iio_dev_attr *iio_attr, *t;
1025
1026	iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1027	if (iio_attr == NULL)
1028		return -ENOMEM;
1029	ret = __iio_device_attr_init(&iio_attr->dev_attr,
1030				     postfix, chan,
1031				     readfunc, writefunc, shared_by);
1032	if (ret)
1033		goto error_iio_dev_attr_free;
1034	iio_attr->c = chan;
1035	iio_attr->address = mask;
1036	list_for_each_entry(t, attr_list, l)
1037		if (strcmp(t->dev_attr.attr.name,
1038			   iio_attr->dev_attr.attr.name) == 0) {
1039			if (shared_by == IIO_SEPARATE)
1040				dev_err(dev, "tried to double register : %s\n",
1041					t->dev_attr.attr.name);
1042			ret = -EBUSY;
1043			goto error_device_attr_deinit;
1044		}
1045	list_add(&iio_attr->l, attr_list);
1046
1047	return 0;
1048
1049error_device_attr_deinit:
1050	__iio_device_attr_deinit(&iio_attr->dev_attr);
1051error_iio_dev_attr_free:
1052	kfree(iio_attr);
1053	return ret;
1054}
1055
1056static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1057					 struct iio_chan_spec const *chan,
1058					 enum iio_shared_by shared_by,
1059					 const long *infomask)
1060{
1061	int i, ret, attrcount = 0;
1062
1063	for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1064		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1065			return -EINVAL;
1066		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1067					     chan,
1068					     &iio_read_channel_info,
1069					     &iio_write_channel_info,
1070					     i,
1071					     shared_by,
1072					     &indio_dev->dev,
1073					     &indio_dev->channel_attr_list);
1074		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1075			continue;
1076		else if (ret < 0)
1077			return ret;
1078		attrcount++;
1079	}
1080
1081	return attrcount;
1082}
1083
1084static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1085					       struct iio_chan_spec const *chan,
1086					       enum iio_shared_by shared_by,
1087					       const long *infomask)
1088{
1089	int i, ret, attrcount = 0;
1090	char *avail_postfix;
1091
1092	for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1093		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1094			return -EINVAL;
1095		avail_postfix = kasprintf(GFP_KERNEL,
1096					  "%s_available",
1097					  iio_chan_info_postfix[i]);
1098		if (!avail_postfix)
1099			return -ENOMEM;
1100
1101		ret = __iio_add_chan_devattr(avail_postfix,
1102					     chan,
1103					     &iio_read_channel_info_avail,
1104					     NULL,
1105					     i,
1106					     shared_by,
1107					     &indio_dev->dev,
1108					     &indio_dev->channel_attr_list);
1109		kfree(avail_postfix);
1110		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1111			continue;
1112		else if (ret < 0)
1113			return ret;
1114		attrcount++;
1115	}
1116
1117	return attrcount;
1118}
1119
1120static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1121					struct iio_chan_spec const *chan)
1122{
1123	int ret, attrcount = 0;
1124	const struct iio_chan_spec_ext_info *ext_info;
1125
1126	if (chan->channel < 0)
1127		return 0;
1128	ret = iio_device_add_info_mask_type(indio_dev, chan,
1129					    IIO_SEPARATE,
1130					    &chan->info_mask_separate);
1131	if (ret < 0)
1132		return ret;
1133	attrcount += ret;
1134
1135	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1136						  IIO_SEPARATE,
1137						  &chan->
1138						  info_mask_separate_available);
1139	if (ret < 0)
1140		return ret;
1141	attrcount += ret;
1142
1143	ret = iio_device_add_info_mask_type(indio_dev, chan,
1144					    IIO_SHARED_BY_TYPE,
1145					    &chan->info_mask_shared_by_type);
1146	if (ret < 0)
1147		return ret;
1148	attrcount += ret;
1149
1150	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1151						  IIO_SHARED_BY_TYPE,
1152						  &chan->
1153						  info_mask_shared_by_type_available);
1154	if (ret < 0)
1155		return ret;
1156	attrcount += ret;
1157
1158	ret = iio_device_add_info_mask_type(indio_dev, chan,
1159					    IIO_SHARED_BY_DIR,
1160					    &chan->info_mask_shared_by_dir);
1161	if (ret < 0)
1162		return ret;
1163	attrcount += ret;
1164
1165	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1166						  IIO_SHARED_BY_DIR,
1167						  &chan->info_mask_shared_by_dir_available);
1168	if (ret < 0)
1169		return ret;
1170	attrcount += ret;
1171
1172	ret = iio_device_add_info_mask_type(indio_dev, chan,
1173					    IIO_SHARED_BY_ALL,
1174					    &chan->info_mask_shared_by_all);
1175	if (ret < 0)
1176		return ret;
1177	attrcount += ret;
1178
1179	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1180						  IIO_SHARED_BY_ALL,
1181						  &chan->info_mask_shared_by_all_available);
1182	if (ret < 0)
1183		return ret;
1184	attrcount += ret;
1185
1186	if (chan->ext_info) {
1187		unsigned int i = 0;
1188		for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1189			ret = __iio_add_chan_devattr(ext_info->name,
1190					chan,
1191					ext_info->read ?
1192					    &iio_read_channel_ext_info : NULL,
1193					ext_info->write ?
1194					    &iio_write_channel_ext_info : NULL,
1195					i,
1196					ext_info->shared,
1197					&indio_dev->dev,
1198					&indio_dev->channel_attr_list);
1199			i++;
1200			if (ret == -EBUSY && ext_info->shared)
1201				continue;
1202
1203			if (ret)
1204				return ret;
1205
1206			attrcount++;
1207		}
1208	}
1209
1210	return attrcount;
1211}
1212
1213/**
1214 * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1215 * @attr_list: List of IIO device attributes
1216 *
1217 * This function frees the memory allocated for each of the IIO device
1218 * attributes in the list.
1219 */
1220void iio_free_chan_devattr_list(struct list_head *attr_list)
1221{
1222	struct iio_dev_attr *p, *n;
1223
1224	list_for_each_entry_safe(p, n, attr_list, l) {
1225		kfree(p->dev_attr.attr.name);
1226		list_del(&p->l);
1227		kfree(p);
1228	}
1229}
1230
1231static ssize_t iio_show_dev_name(struct device *dev,
1232				 struct device_attribute *attr,
1233				 char *buf)
1234{
1235	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1236	return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
1237}
1238
1239static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
1240
1241static ssize_t iio_show_timestamp_clock(struct device *dev,
1242					struct device_attribute *attr,
1243					char *buf)
1244{
1245	const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1246	const clockid_t clk = iio_device_get_clock(indio_dev);
1247	const char *name;
1248	ssize_t sz;
1249
1250	switch (clk) {
1251	case CLOCK_REALTIME:
1252		name = "realtime\n";
1253		sz = sizeof("realtime\n");
1254		break;
1255	case CLOCK_MONOTONIC:
1256		name = "monotonic\n";
1257		sz = sizeof("monotonic\n");
1258		break;
1259	case CLOCK_MONOTONIC_RAW:
1260		name = "monotonic_raw\n";
1261		sz = sizeof("monotonic_raw\n");
1262		break;
1263	case CLOCK_REALTIME_COARSE:
1264		name = "realtime_coarse\n";
1265		sz = sizeof("realtime_coarse\n");
1266		break;
1267	case CLOCK_MONOTONIC_COARSE:
1268		name = "monotonic_coarse\n";
1269		sz = sizeof("monotonic_coarse\n");
1270		break;
1271	case CLOCK_BOOTTIME:
1272		name = "boottime\n";
1273		sz = sizeof("boottime\n");
1274		break;
1275	case CLOCK_TAI:
1276		name = "tai\n";
1277		sz = sizeof("tai\n");
1278		break;
1279	default:
1280		BUG();
1281	}
1282
1283	memcpy(buf, name, sz);
1284	return sz;
1285}
1286
1287static ssize_t iio_store_timestamp_clock(struct device *dev,
1288					 struct device_attribute *attr,
1289					 const char *buf, size_t len)
1290{
1291	clockid_t clk;
1292	int ret;
1293
1294	if (sysfs_streq(buf, "realtime"))
1295		clk = CLOCK_REALTIME;
1296	else if (sysfs_streq(buf, "monotonic"))
1297		clk = CLOCK_MONOTONIC;
1298	else if (sysfs_streq(buf, "monotonic_raw"))
1299		clk = CLOCK_MONOTONIC_RAW;
1300	else if (sysfs_streq(buf, "realtime_coarse"))
1301		clk = CLOCK_REALTIME_COARSE;
1302	else if (sysfs_streq(buf, "monotonic_coarse"))
1303		clk = CLOCK_MONOTONIC_COARSE;
1304	else if (sysfs_streq(buf, "boottime"))
1305		clk = CLOCK_BOOTTIME;
1306	else if (sysfs_streq(buf, "tai"))
1307		clk = CLOCK_TAI;
1308	else
1309		return -EINVAL;
1310
1311	ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1312	if (ret)
1313		return ret;
1314
1315	return len;
1316}
1317
1318static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1319		   iio_show_timestamp_clock, iio_store_timestamp_clock);
1320
1321static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1322{
1323	int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1324	struct iio_dev_attr *p;
1325	struct attribute **attr, *clk = NULL;
1326
1327	/* First count elements in any existing group */
1328	if (indio_dev->info->attrs) {
1329		attr = indio_dev->info->attrs->attrs;
1330		while (*attr++ != NULL)
1331			attrcount_orig++;
1332	}
1333	attrcount = attrcount_orig;
1334	/*
1335	 * New channel registration method - relies on the fact a group does
1336	 * not need to be initialized if its name is NULL.
1337	 */
1338	if (indio_dev->channels)
1339		for (i = 0; i < indio_dev->num_channels; i++) {
1340			const struct iio_chan_spec *chan =
1341				&indio_dev->channels[i];
1342
1343			if (chan->type == IIO_TIMESTAMP)
1344				clk = &dev_attr_current_timestamp_clock.attr;
1345
1346			ret = iio_device_add_channel_sysfs(indio_dev, chan);
1347			if (ret < 0)
1348				goto error_clear_attrs;
1349			attrcount += ret;
1350		}
1351
1352	if (indio_dev->event_interface)
1353		clk = &dev_attr_current_timestamp_clock.attr;
1354
1355	if (indio_dev->name)
1356		attrcount++;
1357	if (clk)
1358		attrcount++;
1359
1360	indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
1361						   sizeof(indio_dev->chan_attr_group.attrs[0]),
1362						   GFP_KERNEL);
1363	if (indio_dev->chan_attr_group.attrs == NULL) {
1364		ret = -ENOMEM;
1365		goto error_clear_attrs;
1366	}
1367	/* Copy across original attributes */
1368	if (indio_dev->info->attrs)
1369		memcpy(indio_dev->chan_attr_group.attrs,
1370		       indio_dev->info->attrs->attrs,
1371		       sizeof(indio_dev->chan_attr_group.attrs[0])
1372		       *attrcount_orig);
1373	attrn = attrcount_orig;
1374	/* Add all elements from the list. */
1375	list_for_each_entry(p, &indio_dev->channel_attr_list, l)
1376		indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1377	if (indio_dev->name)
1378		indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1379	if (clk)
1380		indio_dev->chan_attr_group.attrs[attrn++] = clk;
1381
1382	indio_dev->groups[indio_dev->groupcounter++] =
1383		&indio_dev->chan_attr_group;
1384
1385	return 0;
1386
1387error_clear_attrs:
1388	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1389
1390	return ret;
1391}
1392
1393static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1394{
1395
1396	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1397	kfree(indio_dev->chan_attr_group.attrs);
1398	indio_dev->chan_attr_group.attrs = NULL;
1399}
1400
1401static void iio_dev_release(struct device *device)
1402{
1403	struct iio_dev *indio_dev = dev_to_iio_dev(device);
1404	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1405		iio_device_unregister_trigger_consumer(indio_dev);
1406	iio_device_unregister_eventset(indio_dev);
1407	iio_device_unregister_sysfs(indio_dev);
1408
1409	iio_buffer_put(indio_dev->buffer);
1410
1411	ida_simple_remove(&iio_ida, indio_dev->id);
1412	kfree(indio_dev);
1413}
1414
1415struct device_type iio_device_type = {
1416	.name = "iio_device",
1417	.release = iio_dev_release,
1418};
1419
1420/**
1421 * iio_device_alloc() - allocate an iio_dev from a driver
1422 * @sizeof_priv:	Space to allocate for private structure.
1423 **/
1424struct iio_dev *iio_device_alloc(int sizeof_priv)
1425{
1426	struct iio_dev *dev;
1427	size_t alloc_size;
1428
1429	alloc_size = sizeof(struct iio_dev);
1430	if (sizeof_priv) {
1431		alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1432		alloc_size += sizeof_priv;
1433	}
1434	/* ensure 32-byte alignment of whole construct ? */
1435	alloc_size += IIO_ALIGN - 1;
1436
1437	dev = kzalloc(alloc_size, GFP_KERNEL);
1438
1439	if (dev) {
1440		dev->dev.groups = dev->groups;
1441		dev->dev.type = &iio_device_type;
1442		dev->dev.bus = &iio_bus_type;
1443		device_initialize(&dev->dev);
1444		dev_set_drvdata(&dev->dev, (void *)dev);
1445		mutex_init(&dev->mlock);
1446		mutex_init(&dev->info_exist_lock);
1447		INIT_LIST_HEAD(&dev->channel_attr_list);
1448
1449		dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1450		if (dev->id < 0) {
1451			/* cannot use a dev_err as the name isn't available */
1452			pr_err("failed to get device id\n");
1453			kfree(dev);
1454			return NULL;
1455		}
1456		dev_set_name(&dev->dev, "iio:device%d", dev->id);
1457		INIT_LIST_HEAD(&dev->buffer_list);
1458	}
1459
1460	return dev;
1461}
1462EXPORT_SYMBOL(iio_device_alloc);
1463
1464/**
1465 * iio_device_free() - free an iio_dev from a driver
1466 * @dev:		the iio_dev associated with the device
1467 **/
1468void iio_device_free(struct iio_dev *dev)
1469{
1470	if (dev)
1471		put_device(&dev->dev);
1472}
1473EXPORT_SYMBOL(iio_device_free);
1474
1475static void devm_iio_device_release(struct device *dev, void *res)
1476{
1477	iio_device_free(*(struct iio_dev **)res);
1478}
1479
1480int devm_iio_device_match(struct device *dev, void *res, void *data)
1481{
1482	struct iio_dev **r = res;
1483	if (!r || !*r) {
1484		WARN_ON(!r || !*r);
1485		return 0;
1486	}
1487	return *r == data;
1488}
1489EXPORT_SYMBOL_GPL(devm_iio_device_match);
1490
1491/**
1492 * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1493 * @dev:		Device to allocate iio_dev for
1494 * @sizeof_priv:	Space to allocate for private structure.
1495 *
1496 * Managed iio_device_alloc. iio_dev allocated with this function is
1497 * automatically freed on driver detach.
1498 *
1499 * If an iio_dev allocated with this function needs to be freed separately,
1500 * devm_iio_device_free() must be used.
1501 *
1502 * RETURNS:
1503 * Pointer to allocated iio_dev on success, NULL on failure.
1504 */
1505struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1506{
1507	struct iio_dev **ptr, *iio_dev;
1508
1509	ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1510			   GFP_KERNEL);
1511	if (!ptr)
1512		return NULL;
1513
1514	iio_dev = iio_device_alloc(sizeof_priv);
1515	if (iio_dev) {
1516		*ptr = iio_dev;
1517		devres_add(dev, ptr);
1518	} else {
1519		devres_free(ptr);
1520	}
1521
1522	return iio_dev;
1523}
1524EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1525
1526/**
1527 * devm_iio_device_free - Resource-managed iio_device_free()
1528 * @dev:		Device this iio_dev belongs to
1529 * @iio_dev:		the iio_dev associated with the device
1530 *
1531 * Free iio_dev allocated with devm_iio_device_alloc().
1532 */
1533void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1534{
1535	int rc;
1536
1537	rc = devres_release(dev, devm_iio_device_release,
1538			    devm_iio_device_match, iio_dev);
1539	WARN_ON(rc);
1540}
1541EXPORT_SYMBOL_GPL(devm_iio_device_free);
1542
1543/**
1544 * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1545 * @inode:	Inode structure for identifying the device in the file system
1546 * @filp:	File structure for iio device used to keep and later access
1547 *		private data
1548 *
1549 * Return: 0 on success or -EBUSY if the device is already opened
1550 **/
1551static int iio_chrdev_open(struct inode *inode, struct file *filp)
1552{
1553	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1554						struct iio_dev, chrdev);
1555
1556	if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1557		return -EBUSY;
1558
1559	iio_device_get(indio_dev);
1560
1561	filp->private_data = indio_dev;
1562
1563	return 0;
1564}
1565
1566/**
1567 * iio_chrdev_release() - chrdev file close buffer access and ioctls
1568 * @inode:	Inode structure pointer for the char device
1569 * @filp:	File structure pointer for the char device
1570 *
1571 * Return: 0 for successful release
1572 */
1573static int iio_chrdev_release(struct inode *inode, struct file *filp)
1574{
1575	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1576						struct iio_dev, chrdev);
1577	clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1578	iio_device_put(indio_dev);
1579
1580	return 0;
1581}
1582
1583/* Somewhat of a cross file organization violation - ioctls here are actually
1584 * event related */
1585static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1586{
1587	struct iio_dev *indio_dev = filp->private_data;
1588	int __user *ip = (int __user *)arg;
1589	int fd;
1590
1591	if (!indio_dev->info)
1592		return -ENODEV;
1593
1594	if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1595		fd = iio_event_getfd(indio_dev);
1596		if (fd < 0)
1597			return fd;
1598		if (copy_to_user(ip, &fd, sizeof(fd)))
1599			return -EFAULT;
1600		return 0;
1601	}
1602	return -EINVAL;
1603}
1604
1605static const struct file_operations iio_buffer_fileops = {
1606	.read = iio_buffer_read_first_n_outer_addr,
1607	.release = iio_chrdev_release,
1608	.open = iio_chrdev_open,
1609	.poll = iio_buffer_poll_addr,
1610	.owner = THIS_MODULE,
1611	.llseek = noop_llseek,
1612	.unlocked_ioctl = iio_ioctl,
1613	.compat_ioctl = iio_ioctl,
1614};
1615
1616static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1617{
1618	int i, j;
1619	const struct iio_chan_spec *channels = indio_dev->channels;
1620
1621	if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1622		return 0;
1623
1624	for (i = 0; i < indio_dev->num_channels - 1; i++) {
1625		if (channels[i].scan_index < 0)
1626			continue;
1627		for (j = i + 1; j < indio_dev->num_channels; j++)
1628			if (channels[i].scan_index == channels[j].scan_index) {
1629				dev_err(&indio_dev->dev,
1630					"Duplicate scan index %d\n",
1631					channels[i].scan_index);
1632				return -EINVAL;
1633			}
1634	}
1635
1636	return 0;
1637}
1638
1639static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1640
1641int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1642{
1643	int ret;
1644
1645	indio_dev->driver_module = this_mod;
1646	/* If the calling driver did not initialize of_node, do it here */
1647	if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1648		indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1649
1650	ret = iio_check_unique_scan_index(indio_dev);
1651	if (ret < 0)
1652		return ret;
1653
1654	if (!indio_dev->info)
1655		return -EINVAL;
1656
1657	/* configure elements for the chrdev */
1658	indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1659
1660	iio_device_register_debugfs(indio_dev);
1661
1662	ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1663	if (ret) {
1664		dev_err(indio_dev->dev.parent,
1665			"Failed to create buffer sysfs interfaces\n");
1666		goto error_unreg_debugfs;
1667	}
1668
1669	ret = iio_device_register_sysfs(indio_dev);
1670	if (ret) {
1671		dev_err(indio_dev->dev.parent,
1672			"Failed to register sysfs interfaces\n");
1673		goto error_buffer_free_sysfs;
1674	}
1675	ret = iio_device_register_eventset(indio_dev);
1676	if (ret) {
1677		dev_err(indio_dev->dev.parent,
1678			"Failed to register event set\n");
1679		goto error_free_sysfs;
1680	}
1681	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1682		iio_device_register_trigger_consumer(indio_dev);
1683
1684	if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1685		indio_dev->setup_ops == NULL)
1686		indio_dev->setup_ops = &noop_ring_setup_ops;
1687
1688	cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1689
1690	indio_dev->chrdev.owner = this_mod;
1691
1692	ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev);
1693	if (ret < 0)
1694		goto error_unreg_eventset;
1695
1696	return 0;
1697
1698error_unreg_eventset:
1699	iio_device_unregister_eventset(indio_dev);
1700error_free_sysfs:
1701	iio_device_unregister_sysfs(indio_dev);
1702error_buffer_free_sysfs:
1703	iio_buffer_free_sysfs_and_mask(indio_dev);
1704error_unreg_debugfs:
1705	iio_device_unregister_debugfs(indio_dev);
1706	return ret;
1707}
1708EXPORT_SYMBOL(__iio_device_register);
1709
1710/**
1711 * iio_device_unregister() - unregister a device from the IIO subsystem
1712 * @indio_dev:		Device structure representing the device.
1713 **/
1714void iio_device_unregister(struct iio_dev *indio_dev)
1715{
1716	cdev_device_del(&indio_dev->chrdev, &indio_dev->dev);
1717
1718	mutex_lock(&indio_dev->info_exist_lock);
1719
1720	iio_device_unregister_debugfs(indio_dev);
1721
1722	iio_disable_all_buffers(indio_dev);
1723
1724	indio_dev->info = NULL;
1725
1726	iio_device_wakeup_eventset(indio_dev);
1727	iio_buffer_wakeup_poll(indio_dev);
1728
1729	mutex_unlock(&indio_dev->info_exist_lock);
1730
1731	iio_buffer_free_sysfs_and_mask(indio_dev);
1732}
1733EXPORT_SYMBOL(iio_device_unregister);
1734
1735static void devm_iio_device_unreg(struct device *dev, void *res)
1736{
1737	iio_device_unregister(*(struct iio_dev **)res);
1738}
1739
1740int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
1741			       struct module *this_mod)
1742{
1743	struct iio_dev **ptr;
1744	int ret;
1745
1746	ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1747	if (!ptr)
1748		return -ENOMEM;
1749
1750	*ptr = indio_dev;
1751	ret = __iio_device_register(indio_dev, this_mod);
1752	if (!ret)
1753		devres_add(dev, ptr);
1754	else
1755		devres_free(ptr);
1756
1757	return ret;
1758}
1759EXPORT_SYMBOL_GPL(__devm_iio_device_register);
1760
1761/**
1762 * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1763 * @dev:	Device this iio_dev belongs to
1764 * @indio_dev:	the iio_dev associated with the device
1765 *
1766 * Unregister iio_dev registered with devm_iio_device_register().
1767 */
1768void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1769{
1770	int rc;
1771
1772	rc = devres_release(dev, devm_iio_device_unreg,
1773			    devm_iio_device_match, indio_dev);
1774	WARN_ON(rc);
1775}
1776EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1777
1778/**
1779 * iio_device_claim_direct_mode - Keep device in direct mode
1780 * @indio_dev:	the iio_dev associated with the device
1781 *
1782 * If the device is in direct mode it is guaranteed to stay
1783 * that way until iio_device_release_direct_mode() is called.
1784 *
1785 * Use with iio_device_release_direct_mode()
1786 *
1787 * Returns: 0 on success, -EBUSY on failure
1788 */
1789int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1790{
1791	mutex_lock(&indio_dev->mlock);
1792
1793	if (iio_buffer_enabled(indio_dev)) {
1794		mutex_unlock(&indio_dev->mlock);
1795		return -EBUSY;
1796	}
1797	return 0;
1798}
1799EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1800
1801/**
1802 * iio_device_release_direct_mode - releases claim on direct mode
1803 * @indio_dev:	the iio_dev associated with the device
1804 *
1805 * Release the claim. Device is no longer guaranteed to stay
1806 * in direct mode.
1807 *
1808 * Use with iio_device_claim_direct_mode()
1809 */
1810void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1811{
1812	mutex_unlock(&indio_dev->mlock);
1813}
1814EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1815
1816subsys_initcall(iio_init);
1817module_exit(iio_exit);
1818
1819MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1820MODULE_DESCRIPTION("Industrial I/O core");
1821MODULE_LICENSE("GPL");