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/property.h>
23 #include <linux/sched.h>
24 #include <linux/wait.h>
25 #include <linux/cdev.h>
26 #include <linux/slab.h>
27 #include <linux/anon_inodes.h>
28 #include <linux/debugfs.h>
29 #include <linux/mutex.h>
30 #include <linux/iio/iio.h>
31 #include "iio_core.h"
32 #include "iio_core_trigger.h"
33 #include <linux/iio/sysfs.h>
34 #include <linux/iio/events.h>
35 #include <linux/iio/buffer.h>
36 #include <linux/iio/buffer_impl.h>
37 
38 /* IDA to assign each registered device a unique id */
39 static DEFINE_IDA(iio_ida);
40 
41 static dev_t iio_devt;
42 
43 #define IIO_DEV_MAX 256
44 struct bus_type iio_bus_type = {
45 	.name = "iio",
46 };
47 EXPORT_SYMBOL(iio_bus_type);
48 
49 static struct dentry *iio_debugfs_dentry;
50 
51 static const char * const iio_direction[] = {
52 	[0] = "in",
53 	[1] = "out",
54 };
55 
56 static const char * const iio_chan_type_name_spec[] = {
57 	[IIO_VOLTAGE] = "voltage",
58 	[IIO_CURRENT] = "current",
59 	[IIO_POWER] = "power",
60 	[IIO_ACCEL] = "accel",
61 	[IIO_ANGL_VEL] = "anglvel",
62 	[IIO_MAGN] = "magn",
63 	[IIO_LIGHT] = "illuminance",
64 	[IIO_INTENSITY] = "intensity",
65 	[IIO_PROXIMITY] = "proximity",
66 	[IIO_TEMP] = "temp",
67 	[IIO_INCLI] = "incli",
68 	[IIO_ROT] = "rot",
69 	[IIO_ANGL] = "angl",
70 	[IIO_TIMESTAMP] = "timestamp",
71 	[IIO_CAPACITANCE] = "capacitance",
72 	[IIO_ALTVOLTAGE] = "altvoltage",
73 	[IIO_CCT] = "cct",
74 	[IIO_PRESSURE] = "pressure",
75 	[IIO_HUMIDITYRELATIVE] = "humidityrelative",
76 	[IIO_ACTIVITY] = "activity",
77 	[IIO_STEPS] = "steps",
78 	[IIO_ENERGY] = "energy",
79 	[IIO_DISTANCE] = "distance",
80 	[IIO_VELOCITY] = "velocity",
81 	[IIO_CONCENTRATION] = "concentration",
82 	[IIO_RESISTANCE] = "resistance",
83 	[IIO_PH] = "ph",
84 	[IIO_UVINDEX] = "uvindex",
85 	[IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
86 	[IIO_COUNT] = "count",
87 	[IIO_INDEX] = "index",
88 	[IIO_GRAVITY]  = "gravity",
89 	[IIO_POSITIONRELATIVE]  = "positionrelative",
90 	[IIO_PHASE] = "phase",
91 	[IIO_MASSCONCENTRATION] = "massconcentration",
92 };
93 
94 static const char * const iio_modifier_names[] = {
95 	[IIO_MOD_X] = "x",
96 	[IIO_MOD_Y] = "y",
97 	[IIO_MOD_Z] = "z",
98 	[IIO_MOD_X_AND_Y] = "x&y",
99 	[IIO_MOD_X_AND_Z] = "x&z",
100 	[IIO_MOD_Y_AND_Z] = "y&z",
101 	[IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
102 	[IIO_MOD_X_OR_Y] = "x|y",
103 	[IIO_MOD_X_OR_Z] = "x|z",
104 	[IIO_MOD_Y_OR_Z] = "y|z",
105 	[IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
106 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
107 	[IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
108 	[IIO_MOD_LIGHT_BOTH] = "both",
109 	[IIO_MOD_LIGHT_IR] = "ir",
110 	[IIO_MOD_LIGHT_CLEAR] = "clear",
111 	[IIO_MOD_LIGHT_RED] = "red",
112 	[IIO_MOD_LIGHT_GREEN] = "green",
113 	[IIO_MOD_LIGHT_BLUE] = "blue",
114 	[IIO_MOD_LIGHT_UV] = "uv",
115 	[IIO_MOD_LIGHT_DUV] = "duv",
116 	[IIO_MOD_QUATERNION] = "quaternion",
117 	[IIO_MOD_TEMP_AMBIENT] = "ambient",
118 	[IIO_MOD_TEMP_OBJECT] = "object",
119 	[IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
120 	[IIO_MOD_NORTH_TRUE] = "from_north_true",
121 	[IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
122 	[IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
123 	[IIO_MOD_RUNNING] = "running",
124 	[IIO_MOD_JOGGING] = "jogging",
125 	[IIO_MOD_WALKING] = "walking",
126 	[IIO_MOD_STILL] = "still",
127 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
128 	[IIO_MOD_I] = "i",
129 	[IIO_MOD_Q] = "q",
130 	[IIO_MOD_CO2] = "co2",
131 	[IIO_MOD_VOC] = "voc",
132 	[IIO_MOD_PM1] = "pm1",
133 	[IIO_MOD_PM2P5] = "pm2p5",
134 	[IIO_MOD_PM4] = "pm4",
135 	[IIO_MOD_PM10] = "pm10",
136 };
137 
138 /* relies on pairs of these shared then separate */
139 static const char * const iio_chan_info_postfix[] = {
140 	[IIO_CHAN_INFO_RAW] = "raw",
141 	[IIO_CHAN_INFO_PROCESSED] = "input",
142 	[IIO_CHAN_INFO_SCALE] = "scale",
143 	[IIO_CHAN_INFO_OFFSET] = "offset",
144 	[IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
145 	[IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
146 	[IIO_CHAN_INFO_PEAK] = "peak_raw",
147 	[IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
148 	[IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
149 	[IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
150 	[IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
151 	= "filter_low_pass_3db_frequency",
152 	[IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
153 	= "filter_high_pass_3db_frequency",
154 	[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
155 	[IIO_CHAN_INFO_FREQUENCY] = "frequency",
156 	[IIO_CHAN_INFO_PHASE] = "phase",
157 	[IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
158 	[IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
159 	[IIO_CHAN_INFO_INT_TIME] = "integration_time",
160 	[IIO_CHAN_INFO_ENABLE] = "en",
161 	[IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
162 	[IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
163 	[IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
164 	[IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
165 	[IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
166 	[IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
167 };
168 
169 /**
170  * iio_find_channel_from_si() - get channel from its scan index
171  * @indio_dev:		device
172  * @si:			scan index to match
173  */
174 const struct iio_chan_spec
175 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
176 {
177 	int i;
178 
179 	for (i = 0; i < indio_dev->num_channels; i++)
180 		if (indio_dev->channels[i].scan_index == si)
181 			return &indio_dev->channels[i];
182 	return NULL;
183 }
184 
185 /* This turns up an awful lot */
186 ssize_t iio_read_const_attr(struct device *dev,
187 			    struct device_attribute *attr,
188 			    char *buf)
189 {
190 	return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
191 }
192 EXPORT_SYMBOL(iio_read_const_attr);
193 
194 static int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
195 {
196 	int ret;
197 	const struct iio_event_interface *ev_int = indio_dev->event_interface;
198 
199 	ret = mutex_lock_interruptible(&indio_dev->mlock);
200 	if (ret)
201 		return ret;
202 	if ((ev_int && iio_event_enabled(ev_int)) ||
203 	    iio_buffer_enabled(indio_dev)) {
204 		mutex_unlock(&indio_dev->mlock);
205 		return -EBUSY;
206 	}
207 	indio_dev->clock_id = clock_id;
208 	mutex_unlock(&indio_dev->mlock);
209 
210 	return 0;
211 }
212 
213 /**
214  * iio_get_time_ns() - utility function to get a time stamp for events etc
215  * @indio_dev: device
216  */
217 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
218 {
219 	struct timespec64 tp;
220 
221 	switch (iio_device_get_clock(indio_dev)) {
222 	case CLOCK_REALTIME:
223 		return ktime_get_real_ns();
224 	case CLOCK_MONOTONIC:
225 		return ktime_get_ns();
226 	case CLOCK_MONOTONIC_RAW:
227 		return ktime_get_raw_ns();
228 	case CLOCK_REALTIME_COARSE:
229 		return ktime_to_ns(ktime_get_coarse_real());
230 	case CLOCK_MONOTONIC_COARSE:
231 		ktime_get_coarse_ts64(&tp);
232 		return timespec64_to_ns(&tp);
233 	case CLOCK_BOOTTIME:
234 		return ktime_get_boot_ns();
235 	case CLOCK_TAI:
236 		return ktime_get_tai_ns();
237 	default:
238 		BUG();
239 	}
240 }
241 EXPORT_SYMBOL(iio_get_time_ns);
242 
243 /**
244  * iio_get_time_res() - utility function to get time stamp clock resolution in
245  *                      nano seconds.
246  * @indio_dev: device
247  */
248 unsigned int iio_get_time_res(const struct iio_dev *indio_dev)
249 {
250 	switch (iio_device_get_clock(indio_dev)) {
251 	case CLOCK_REALTIME:
252 	case CLOCK_MONOTONIC:
253 	case CLOCK_MONOTONIC_RAW:
254 	case CLOCK_BOOTTIME:
255 	case CLOCK_TAI:
256 		return hrtimer_resolution;
257 	case CLOCK_REALTIME_COARSE:
258 	case CLOCK_MONOTONIC_COARSE:
259 		return LOW_RES_NSEC;
260 	default:
261 		BUG();
262 	}
263 }
264 EXPORT_SYMBOL(iio_get_time_res);
265 
266 static int __init iio_init(void)
267 {
268 	int ret;
269 
270 	/* Register sysfs bus */
271 	ret  = bus_register(&iio_bus_type);
272 	if (ret < 0) {
273 		pr_err("could not register bus type\n");
274 		goto error_nothing;
275 	}
276 
277 	ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
278 	if (ret < 0) {
279 		pr_err("failed to allocate char dev region\n");
280 		goto error_unregister_bus_type;
281 	}
282 
283 	iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
284 
285 	return 0;
286 
287 error_unregister_bus_type:
288 	bus_unregister(&iio_bus_type);
289 error_nothing:
290 	return ret;
291 }
292 
293 static void __exit iio_exit(void)
294 {
295 	if (iio_devt)
296 		unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
297 	bus_unregister(&iio_bus_type);
298 	debugfs_remove(iio_debugfs_dentry);
299 }
300 
301 #if defined(CONFIG_DEBUG_FS)
302 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
303 			      size_t count, loff_t *ppos)
304 {
305 	struct iio_dev *indio_dev = file->private_data;
306 	char buf[20];
307 	unsigned val = 0;
308 	ssize_t len;
309 	int ret;
310 
311 	ret = indio_dev->info->debugfs_reg_access(indio_dev,
312 						  indio_dev->cached_reg_addr,
313 						  0, &val);
314 	if (ret) {
315 		dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
316 		return ret;
317 	}
318 
319 	len = snprintf(buf, sizeof(buf), "0x%X\n", val);
320 
321 	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
322 }
323 
324 static ssize_t iio_debugfs_write_reg(struct file *file,
325 		     const char __user *userbuf, size_t count, loff_t *ppos)
326 {
327 	struct iio_dev *indio_dev = file->private_data;
328 	unsigned reg, val;
329 	char buf[80];
330 	int ret;
331 
332 	count = min_t(size_t, count, (sizeof(buf)-1));
333 	if (copy_from_user(buf, userbuf, count))
334 		return -EFAULT;
335 
336 	buf[count] = 0;
337 
338 	ret = sscanf(buf, "%i %i", &reg, &val);
339 
340 	switch (ret) {
341 	case 1:
342 		indio_dev->cached_reg_addr = reg;
343 		break;
344 	case 2:
345 		indio_dev->cached_reg_addr = reg;
346 		ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
347 							  val, NULL);
348 		if (ret) {
349 			dev_err(indio_dev->dev.parent, "%s: write failed\n",
350 				__func__);
351 			return ret;
352 		}
353 		break;
354 	default:
355 		return -EINVAL;
356 	}
357 
358 	return count;
359 }
360 
361 static const struct file_operations iio_debugfs_reg_fops = {
362 	.open = simple_open,
363 	.read = iio_debugfs_read_reg,
364 	.write = iio_debugfs_write_reg,
365 };
366 
367 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
368 {
369 	debugfs_remove_recursive(indio_dev->debugfs_dentry);
370 }
371 
372 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
373 {
374 	struct dentry *d;
375 
376 	if (indio_dev->info->debugfs_reg_access == NULL)
377 		return 0;
378 
379 	if (!iio_debugfs_dentry)
380 		return 0;
381 
382 	indio_dev->debugfs_dentry =
383 		debugfs_create_dir(dev_name(&indio_dev->dev),
384 				   iio_debugfs_dentry);
385 	if (indio_dev->debugfs_dentry == NULL) {
386 		dev_warn(indio_dev->dev.parent,
387 			 "Failed to create debugfs directory\n");
388 		return -EFAULT;
389 	}
390 
391 	d = debugfs_create_file("direct_reg_access", 0644,
392 				indio_dev->debugfs_dentry,
393 				indio_dev, &iio_debugfs_reg_fops);
394 	if (!d) {
395 		iio_device_unregister_debugfs(indio_dev);
396 		return -ENOMEM;
397 	}
398 
399 	return 0;
400 }
401 #else
402 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
403 {
404 	return 0;
405 }
406 
407 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
408 {
409 }
410 #endif /* CONFIG_DEBUG_FS */
411 
412 static ssize_t iio_read_channel_ext_info(struct device *dev,
413 				     struct device_attribute *attr,
414 				     char *buf)
415 {
416 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
417 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
418 	const struct iio_chan_spec_ext_info *ext_info;
419 
420 	ext_info = &this_attr->c->ext_info[this_attr->address];
421 
422 	return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
423 }
424 
425 static ssize_t iio_write_channel_ext_info(struct device *dev,
426 				     struct device_attribute *attr,
427 				     const char *buf,
428 					 size_t len)
429 {
430 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
431 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
432 	const struct iio_chan_spec_ext_info *ext_info;
433 
434 	ext_info = &this_attr->c->ext_info[this_attr->address];
435 
436 	return ext_info->write(indio_dev, ext_info->private,
437 			       this_attr->c, buf, len);
438 }
439 
440 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
441 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
442 {
443 	const struct iio_enum *e = (const struct iio_enum *)priv;
444 	unsigned int i;
445 	size_t len = 0;
446 
447 	if (!e->num_items)
448 		return 0;
449 
450 	for (i = 0; i < e->num_items; ++i)
451 		len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
452 
453 	/* replace last space with a newline */
454 	buf[len - 1] = '\n';
455 
456 	return len;
457 }
458 EXPORT_SYMBOL_GPL(iio_enum_available_read);
459 
460 ssize_t iio_enum_read(struct iio_dev *indio_dev,
461 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
462 {
463 	const struct iio_enum *e = (const struct iio_enum *)priv;
464 	int i;
465 
466 	if (!e->get)
467 		return -EINVAL;
468 
469 	i = e->get(indio_dev, chan);
470 	if (i < 0)
471 		return i;
472 	else if (i >= e->num_items)
473 		return -EINVAL;
474 
475 	return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
476 }
477 EXPORT_SYMBOL_GPL(iio_enum_read);
478 
479 ssize_t iio_enum_write(struct iio_dev *indio_dev,
480 	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
481 	size_t len)
482 {
483 	const struct iio_enum *e = (const struct iio_enum *)priv;
484 	int ret;
485 
486 	if (!e->set)
487 		return -EINVAL;
488 
489 	ret = __sysfs_match_string(e->items, e->num_items, buf);
490 	if (ret < 0)
491 		return ret;
492 
493 	ret = e->set(indio_dev, chan, ret);
494 	return ret ? ret : len;
495 }
496 EXPORT_SYMBOL_GPL(iio_enum_write);
497 
498 static const struct iio_mount_matrix iio_mount_idmatrix = {
499 	.rotation = {
500 		"1", "0", "0",
501 		"0", "1", "0",
502 		"0", "0", "1"
503 	}
504 };
505 
506 static int iio_setup_mount_idmatrix(const struct device *dev,
507 				    struct iio_mount_matrix *matrix)
508 {
509 	*matrix = iio_mount_idmatrix;
510 	dev_info(dev, "mounting matrix not found: using identity...\n");
511 	return 0;
512 }
513 
514 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
515 			      const struct iio_chan_spec *chan, char *buf)
516 {
517 	const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
518 					      priv)(indio_dev, chan);
519 
520 	if (IS_ERR(mtx))
521 		return PTR_ERR(mtx);
522 
523 	if (!mtx)
524 		mtx = &iio_mount_idmatrix;
525 
526 	return snprintf(buf, PAGE_SIZE, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
527 			mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
528 			mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
529 			mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
530 }
531 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
532 
533 /**
534  * iio_read_mount_matrix() - retrieve iio device mounting matrix from
535  *                           device "mount-matrix" property
536  * @dev:	device the mounting matrix property is assigned to
537  * @propname:	device specific mounting matrix property name
538  * @matrix:	where to store retrieved matrix
539  *
540  * If device is assigned no mounting matrix property, a default 3x3 identity
541  * matrix will be filled in.
542  *
543  * Return: 0 if success, or a negative error code on failure.
544  */
545 int iio_read_mount_matrix(struct device *dev, const char *propname,
546 			  struct iio_mount_matrix *matrix)
547 {
548 	size_t len = ARRAY_SIZE(iio_mount_idmatrix.rotation);
549 	int err;
550 
551 	err = device_property_read_string_array(dev, propname,
552 						matrix->rotation, len);
553 	if (err == len)
554 		return 0;
555 
556 	if (err >= 0)
557 		/* Invalid number of matrix entries. */
558 		return -EINVAL;
559 
560 	if (err != -EINVAL)
561 		/* Invalid matrix declaration format. */
562 		return err;
563 
564 	/* Matrix was not declared at all: fallback to identity. */
565 	return iio_setup_mount_idmatrix(dev, matrix);
566 }
567 EXPORT_SYMBOL(iio_read_mount_matrix);
568 
569 static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
570 				  int size, const int *vals)
571 {
572 	unsigned long long tmp;
573 	int tmp0, tmp1;
574 	bool scale_db = false;
575 
576 	switch (type) {
577 	case IIO_VAL_INT:
578 		return snprintf(buf, len, "%d", vals[0]);
579 	case IIO_VAL_INT_PLUS_MICRO_DB:
580 		scale_db = true;
581 		/* fall through */
582 	case IIO_VAL_INT_PLUS_MICRO:
583 		if (vals[1] < 0)
584 			return snprintf(buf, len, "-%d.%06u%s", abs(vals[0]),
585 					-vals[1], scale_db ? " dB" : "");
586 		else
587 			return snprintf(buf, len, "%d.%06u%s", vals[0], vals[1],
588 					scale_db ? " dB" : "");
589 	case IIO_VAL_INT_PLUS_NANO:
590 		if (vals[1] < 0)
591 			return snprintf(buf, len, "-%d.%09u", abs(vals[0]),
592 					-vals[1]);
593 		else
594 			return snprintf(buf, len, "%d.%09u", vals[0], vals[1]);
595 	case IIO_VAL_FRACTIONAL:
596 		tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
597 		tmp1 = vals[1];
598 		tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1);
599 		return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
600 	case IIO_VAL_FRACTIONAL_LOG2:
601 		tmp = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
602 		tmp0 = (int)div_s64_rem(tmp, 1000000000LL, &tmp1);
603 		return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
604 	case IIO_VAL_INT_MULTIPLE:
605 	{
606 		int i;
607 		int l = 0;
608 
609 		for (i = 0; i < size; ++i) {
610 			l += snprintf(&buf[l], len - l, "%d ", vals[i]);
611 			if (l >= len)
612 				break;
613 		}
614 		return l;
615 	}
616 	default:
617 		return 0;
618 	}
619 }
620 
621 /**
622  * iio_format_value() - Formats a IIO value into its string representation
623  * @buf:	The buffer to which the formatted value gets written
624  *		which is assumed to be big enough (i.e. PAGE_SIZE).
625  * @type:	One of the IIO_VAL_* constants. This decides how the val
626  *		and val2 parameters are formatted.
627  * @size:	Number of IIO value entries contained in vals
628  * @vals:	Pointer to the values, exact meaning depends on the
629  *		type parameter.
630  *
631  * Return: 0 by default, a negative number on failure or the
632  *	   total number of characters written for a type that belongs
633  *	   to the IIO_VAL_* constant.
634  */
635 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
636 {
637 	ssize_t len;
638 
639 	len = __iio_format_value(buf, PAGE_SIZE, type, size, vals);
640 	if (len >= PAGE_SIZE - 1)
641 		return -EFBIG;
642 
643 	return len + sprintf(buf + len, "\n");
644 }
645 EXPORT_SYMBOL_GPL(iio_format_value);
646 
647 static ssize_t iio_read_channel_info(struct device *dev,
648 				     struct device_attribute *attr,
649 				     char *buf)
650 {
651 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
652 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
653 	int vals[INDIO_MAX_RAW_ELEMENTS];
654 	int ret;
655 	int val_len = 2;
656 
657 	if (indio_dev->info->read_raw_multi)
658 		ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
659 							INDIO_MAX_RAW_ELEMENTS,
660 							vals, &val_len,
661 							this_attr->address);
662 	else
663 		ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
664 				    &vals[0], &vals[1], this_attr->address);
665 
666 	if (ret < 0)
667 		return ret;
668 
669 	return iio_format_value(buf, ret, val_len, vals);
670 }
671 
672 static ssize_t iio_format_avail_list(char *buf, const int *vals,
673 				     int type, int length)
674 {
675 	int i;
676 	ssize_t len = 0;
677 
678 	switch (type) {
679 	case IIO_VAL_INT:
680 		for (i = 0; i < length; i++) {
681 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
682 						  type, 1, &vals[i]);
683 			if (len >= PAGE_SIZE)
684 				return -EFBIG;
685 			if (i < length - 1)
686 				len += snprintf(buf + len, PAGE_SIZE - len,
687 						" ");
688 			else
689 				len += snprintf(buf + len, PAGE_SIZE - len,
690 						"\n");
691 			if (len >= PAGE_SIZE)
692 				return -EFBIG;
693 		}
694 		break;
695 	default:
696 		for (i = 0; i < length / 2; i++) {
697 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
698 						  type, 2, &vals[i * 2]);
699 			if (len >= PAGE_SIZE)
700 				return -EFBIG;
701 			if (i < length / 2 - 1)
702 				len += snprintf(buf + len, PAGE_SIZE - len,
703 						" ");
704 			else
705 				len += snprintf(buf + len, PAGE_SIZE - len,
706 						"\n");
707 			if (len >= PAGE_SIZE)
708 				return -EFBIG;
709 		}
710 	}
711 
712 	return len;
713 }
714 
715 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
716 {
717 	int i;
718 	ssize_t len;
719 
720 	len = snprintf(buf, PAGE_SIZE, "[");
721 	switch (type) {
722 	case IIO_VAL_INT:
723 		for (i = 0; i < 3; i++) {
724 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
725 						  type, 1, &vals[i]);
726 			if (len >= PAGE_SIZE)
727 				return -EFBIG;
728 			if (i < 2)
729 				len += snprintf(buf + len, PAGE_SIZE - len,
730 						" ");
731 			else
732 				len += snprintf(buf + len, PAGE_SIZE - len,
733 						"]\n");
734 			if (len >= PAGE_SIZE)
735 				return -EFBIG;
736 		}
737 		break;
738 	default:
739 		for (i = 0; i < 3; i++) {
740 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
741 						  type, 2, &vals[i * 2]);
742 			if (len >= PAGE_SIZE)
743 				return -EFBIG;
744 			if (i < 2)
745 				len += snprintf(buf + len, PAGE_SIZE - len,
746 						" ");
747 			else
748 				len += snprintf(buf + len, PAGE_SIZE - len,
749 						"]\n");
750 			if (len >= PAGE_SIZE)
751 				return -EFBIG;
752 		}
753 	}
754 
755 	return len;
756 }
757 
758 static ssize_t iio_read_channel_info_avail(struct device *dev,
759 					   struct device_attribute *attr,
760 					   char *buf)
761 {
762 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
763 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
764 	const int *vals;
765 	int ret;
766 	int length;
767 	int type;
768 
769 	ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
770 					  &vals, &type, &length,
771 					  this_attr->address);
772 
773 	if (ret < 0)
774 		return ret;
775 	switch (ret) {
776 	case IIO_AVAIL_LIST:
777 		return iio_format_avail_list(buf, vals, type, length);
778 	case IIO_AVAIL_RANGE:
779 		return iio_format_avail_range(buf, vals, type);
780 	default:
781 		return -EINVAL;
782 	}
783 }
784 
785 /**
786  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
787  * @str: The string to parse
788  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
789  * @integer: The integer part of the number
790  * @fract: The fractional part of the number
791  *
792  * Returns 0 on success, or a negative error code if the string could not be
793  * parsed.
794  */
795 int iio_str_to_fixpoint(const char *str, int fract_mult,
796 	int *integer, int *fract)
797 {
798 	int i = 0, f = 0;
799 	bool integer_part = true, negative = false;
800 
801 	if (fract_mult == 0) {
802 		*fract = 0;
803 
804 		return kstrtoint(str, 0, integer);
805 	}
806 
807 	if (str[0] == '-') {
808 		negative = true;
809 		str++;
810 	} else if (str[0] == '+') {
811 		str++;
812 	}
813 
814 	while (*str) {
815 		if ('0' <= *str && *str <= '9') {
816 			if (integer_part) {
817 				i = i * 10 + *str - '0';
818 			} else {
819 				f += fract_mult * (*str - '0');
820 				fract_mult /= 10;
821 			}
822 		} else if (*str == '\n') {
823 			if (*(str + 1) == '\0')
824 				break;
825 			else
826 				return -EINVAL;
827 		} else if (*str == '.' && integer_part) {
828 			integer_part = false;
829 		} else {
830 			return -EINVAL;
831 		}
832 		str++;
833 	}
834 
835 	if (negative) {
836 		if (i)
837 			i = -i;
838 		else
839 			f = -f;
840 	}
841 
842 	*integer = i;
843 	*fract = f;
844 
845 	return 0;
846 }
847 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
848 
849 static ssize_t iio_write_channel_info(struct device *dev,
850 				      struct device_attribute *attr,
851 				      const char *buf,
852 				      size_t len)
853 {
854 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
855 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
856 	int ret, fract_mult = 100000;
857 	int integer, fract;
858 
859 	/* Assumes decimal - precision based on number of digits */
860 	if (!indio_dev->info->write_raw)
861 		return -EINVAL;
862 
863 	if (indio_dev->info->write_raw_get_fmt)
864 		switch (indio_dev->info->write_raw_get_fmt(indio_dev,
865 			this_attr->c, this_attr->address)) {
866 		case IIO_VAL_INT:
867 			fract_mult = 0;
868 			break;
869 		case IIO_VAL_INT_PLUS_MICRO:
870 			fract_mult = 100000;
871 			break;
872 		case IIO_VAL_INT_PLUS_NANO:
873 			fract_mult = 100000000;
874 			break;
875 		default:
876 			return -EINVAL;
877 		}
878 
879 	ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
880 	if (ret)
881 		return ret;
882 
883 	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
884 					 integer, fract, this_attr->address);
885 	if (ret)
886 		return ret;
887 
888 	return len;
889 }
890 
891 static
892 int __iio_device_attr_init(struct device_attribute *dev_attr,
893 			   const char *postfix,
894 			   struct iio_chan_spec const *chan,
895 			   ssize_t (*readfunc)(struct device *dev,
896 					       struct device_attribute *attr,
897 					       char *buf),
898 			   ssize_t (*writefunc)(struct device *dev,
899 						struct device_attribute *attr,
900 						const char *buf,
901 						size_t len),
902 			   enum iio_shared_by shared_by)
903 {
904 	int ret = 0;
905 	char *name = NULL;
906 	char *full_postfix;
907 	sysfs_attr_init(&dev_attr->attr);
908 
909 	/* Build up postfix of <extend_name>_<modifier>_postfix */
910 	if (chan->modified && (shared_by == IIO_SEPARATE)) {
911 		if (chan->extend_name)
912 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
913 						 iio_modifier_names[chan
914 								    ->channel2],
915 						 chan->extend_name,
916 						 postfix);
917 		else
918 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
919 						 iio_modifier_names[chan
920 								    ->channel2],
921 						 postfix);
922 	} else {
923 		if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
924 			full_postfix = kstrdup(postfix, GFP_KERNEL);
925 		else
926 			full_postfix = kasprintf(GFP_KERNEL,
927 						 "%s_%s",
928 						 chan->extend_name,
929 						 postfix);
930 	}
931 	if (full_postfix == NULL)
932 		return -ENOMEM;
933 
934 	if (chan->differential) { /* Differential can not have modifier */
935 		switch (shared_by) {
936 		case IIO_SHARED_BY_ALL:
937 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
938 			break;
939 		case IIO_SHARED_BY_DIR:
940 			name = kasprintf(GFP_KERNEL, "%s_%s",
941 						iio_direction[chan->output],
942 						full_postfix);
943 			break;
944 		case IIO_SHARED_BY_TYPE:
945 			name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
946 					    iio_direction[chan->output],
947 					    iio_chan_type_name_spec[chan->type],
948 					    iio_chan_type_name_spec[chan->type],
949 					    full_postfix);
950 			break;
951 		case IIO_SEPARATE:
952 			if (!chan->indexed) {
953 				WARN(1, "Differential channels must be indexed\n");
954 				ret = -EINVAL;
955 				goto error_free_full_postfix;
956 			}
957 			name = kasprintf(GFP_KERNEL,
958 					    "%s_%s%d-%s%d_%s",
959 					    iio_direction[chan->output],
960 					    iio_chan_type_name_spec[chan->type],
961 					    chan->channel,
962 					    iio_chan_type_name_spec[chan->type],
963 					    chan->channel2,
964 					    full_postfix);
965 			break;
966 		}
967 	} else { /* Single ended */
968 		switch (shared_by) {
969 		case IIO_SHARED_BY_ALL:
970 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
971 			break;
972 		case IIO_SHARED_BY_DIR:
973 			name = kasprintf(GFP_KERNEL, "%s_%s",
974 						iio_direction[chan->output],
975 						full_postfix);
976 			break;
977 		case IIO_SHARED_BY_TYPE:
978 			name = kasprintf(GFP_KERNEL, "%s_%s_%s",
979 					    iio_direction[chan->output],
980 					    iio_chan_type_name_spec[chan->type],
981 					    full_postfix);
982 			break;
983 
984 		case IIO_SEPARATE:
985 			if (chan->indexed)
986 				name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
987 						    iio_direction[chan->output],
988 						    iio_chan_type_name_spec[chan->type],
989 						    chan->channel,
990 						    full_postfix);
991 			else
992 				name = kasprintf(GFP_KERNEL, "%s_%s_%s",
993 						    iio_direction[chan->output],
994 						    iio_chan_type_name_spec[chan->type],
995 						    full_postfix);
996 			break;
997 		}
998 	}
999 	if (name == NULL) {
1000 		ret = -ENOMEM;
1001 		goto error_free_full_postfix;
1002 	}
1003 	dev_attr->attr.name = name;
1004 
1005 	if (readfunc) {
1006 		dev_attr->attr.mode |= S_IRUGO;
1007 		dev_attr->show = readfunc;
1008 	}
1009 
1010 	if (writefunc) {
1011 		dev_attr->attr.mode |= S_IWUSR;
1012 		dev_attr->store = writefunc;
1013 	}
1014 
1015 error_free_full_postfix:
1016 	kfree(full_postfix);
1017 
1018 	return ret;
1019 }
1020 
1021 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1022 {
1023 	kfree(dev_attr->attr.name);
1024 }
1025 
1026 int __iio_add_chan_devattr(const char *postfix,
1027 			   struct iio_chan_spec const *chan,
1028 			   ssize_t (*readfunc)(struct device *dev,
1029 					       struct device_attribute *attr,
1030 					       char *buf),
1031 			   ssize_t (*writefunc)(struct device *dev,
1032 						struct device_attribute *attr,
1033 						const char *buf,
1034 						size_t len),
1035 			   u64 mask,
1036 			   enum iio_shared_by shared_by,
1037 			   struct device *dev,
1038 			   struct list_head *attr_list)
1039 {
1040 	int ret;
1041 	struct iio_dev_attr *iio_attr, *t;
1042 
1043 	iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1044 	if (iio_attr == NULL)
1045 		return -ENOMEM;
1046 	ret = __iio_device_attr_init(&iio_attr->dev_attr,
1047 				     postfix, chan,
1048 				     readfunc, writefunc, shared_by);
1049 	if (ret)
1050 		goto error_iio_dev_attr_free;
1051 	iio_attr->c = chan;
1052 	iio_attr->address = mask;
1053 	list_for_each_entry(t, attr_list, l)
1054 		if (strcmp(t->dev_attr.attr.name,
1055 			   iio_attr->dev_attr.attr.name) == 0) {
1056 			if (shared_by == IIO_SEPARATE)
1057 				dev_err(dev, "tried to double register : %s\n",
1058 					t->dev_attr.attr.name);
1059 			ret = -EBUSY;
1060 			goto error_device_attr_deinit;
1061 		}
1062 	list_add(&iio_attr->l, attr_list);
1063 
1064 	return 0;
1065 
1066 error_device_attr_deinit:
1067 	__iio_device_attr_deinit(&iio_attr->dev_attr);
1068 error_iio_dev_attr_free:
1069 	kfree(iio_attr);
1070 	return ret;
1071 }
1072 
1073 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1074 					 struct iio_chan_spec const *chan,
1075 					 enum iio_shared_by shared_by,
1076 					 const long *infomask)
1077 {
1078 	int i, ret, attrcount = 0;
1079 
1080 	for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1081 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1082 			return -EINVAL;
1083 		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1084 					     chan,
1085 					     &iio_read_channel_info,
1086 					     &iio_write_channel_info,
1087 					     i,
1088 					     shared_by,
1089 					     &indio_dev->dev,
1090 					     &indio_dev->channel_attr_list);
1091 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1092 			continue;
1093 		else if (ret < 0)
1094 			return ret;
1095 		attrcount++;
1096 	}
1097 
1098 	return attrcount;
1099 }
1100 
1101 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1102 					       struct iio_chan_spec const *chan,
1103 					       enum iio_shared_by shared_by,
1104 					       const long *infomask)
1105 {
1106 	int i, ret, attrcount = 0;
1107 	char *avail_postfix;
1108 
1109 	for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1110 		avail_postfix = kasprintf(GFP_KERNEL,
1111 					  "%s_available",
1112 					  iio_chan_info_postfix[i]);
1113 		if (!avail_postfix)
1114 			return -ENOMEM;
1115 
1116 		ret = __iio_add_chan_devattr(avail_postfix,
1117 					     chan,
1118 					     &iio_read_channel_info_avail,
1119 					     NULL,
1120 					     i,
1121 					     shared_by,
1122 					     &indio_dev->dev,
1123 					     &indio_dev->channel_attr_list);
1124 		kfree(avail_postfix);
1125 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1126 			continue;
1127 		else if (ret < 0)
1128 			return ret;
1129 		attrcount++;
1130 	}
1131 
1132 	return attrcount;
1133 }
1134 
1135 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1136 					struct iio_chan_spec const *chan)
1137 {
1138 	int ret, attrcount = 0;
1139 	const struct iio_chan_spec_ext_info *ext_info;
1140 
1141 	if (chan->channel < 0)
1142 		return 0;
1143 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1144 					    IIO_SEPARATE,
1145 					    &chan->info_mask_separate);
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_SEPARATE,
1152 						  &chan->
1153 						  info_mask_separate_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_TYPE,
1160 					    &chan->info_mask_shared_by_type);
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_TYPE,
1167 						  &chan->
1168 						  info_mask_shared_by_type_available);
1169 	if (ret < 0)
1170 		return ret;
1171 	attrcount += ret;
1172 
1173 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1174 					    IIO_SHARED_BY_DIR,
1175 					    &chan->info_mask_shared_by_dir);
1176 	if (ret < 0)
1177 		return ret;
1178 	attrcount += ret;
1179 
1180 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1181 						  IIO_SHARED_BY_DIR,
1182 						  &chan->info_mask_shared_by_dir_available);
1183 	if (ret < 0)
1184 		return ret;
1185 	attrcount += ret;
1186 
1187 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1188 					    IIO_SHARED_BY_ALL,
1189 					    &chan->info_mask_shared_by_all);
1190 	if (ret < 0)
1191 		return ret;
1192 	attrcount += ret;
1193 
1194 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1195 						  IIO_SHARED_BY_ALL,
1196 						  &chan->info_mask_shared_by_all_available);
1197 	if (ret < 0)
1198 		return ret;
1199 	attrcount += ret;
1200 
1201 	if (chan->ext_info) {
1202 		unsigned int i = 0;
1203 		for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1204 			ret = __iio_add_chan_devattr(ext_info->name,
1205 					chan,
1206 					ext_info->read ?
1207 					    &iio_read_channel_ext_info : NULL,
1208 					ext_info->write ?
1209 					    &iio_write_channel_ext_info : NULL,
1210 					i,
1211 					ext_info->shared,
1212 					&indio_dev->dev,
1213 					&indio_dev->channel_attr_list);
1214 			i++;
1215 			if (ret == -EBUSY && ext_info->shared)
1216 				continue;
1217 
1218 			if (ret)
1219 				return ret;
1220 
1221 			attrcount++;
1222 		}
1223 	}
1224 
1225 	return attrcount;
1226 }
1227 
1228 /**
1229  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1230  * @attr_list: List of IIO device attributes
1231  *
1232  * This function frees the memory allocated for each of the IIO device
1233  * attributes in the list.
1234  */
1235 void iio_free_chan_devattr_list(struct list_head *attr_list)
1236 {
1237 	struct iio_dev_attr *p, *n;
1238 
1239 	list_for_each_entry_safe(p, n, attr_list, l) {
1240 		kfree(p->dev_attr.attr.name);
1241 		list_del(&p->l);
1242 		kfree(p);
1243 	}
1244 }
1245 
1246 static ssize_t iio_show_dev_name(struct device *dev,
1247 				 struct device_attribute *attr,
1248 				 char *buf)
1249 {
1250 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1251 	return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
1252 }
1253 
1254 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
1255 
1256 static ssize_t iio_show_timestamp_clock(struct device *dev,
1257 					struct device_attribute *attr,
1258 					char *buf)
1259 {
1260 	const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1261 	const clockid_t clk = iio_device_get_clock(indio_dev);
1262 	const char *name;
1263 	ssize_t sz;
1264 
1265 	switch (clk) {
1266 	case CLOCK_REALTIME:
1267 		name = "realtime\n";
1268 		sz = sizeof("realtime\n");
1269 		break;
1270 	case CLOCK_MONOTONIC:
1271 		name = "monotonic\n";
1272 		sz = sizeof("monotonic\n");
1273 		break;
1274 	case CLOCK_MONOTONIC_RAW:
1275 		name = "monotonic_raw\n";
1276 		sz = sizeof("monotonic_raw\n");
1277 		break;
1278 	case CLOCK_REALTIME_COARSE:
1279 		name = "realtime_coarse\n";
1280 		sz = sizeof("realtime_coarse\n");
1281 		break;
1282 	case CLOCK_MONOTONIC_COARSE:
1283 		name = "monotonic_coarse\n";
1284 		sz = sizeof("monotonic_coarse\n");
1285 		break;
1286 	case CLOCK_BOOTTIME:
1287 		name = "boottime\n";
1288 		sz = sizeof("boottime\n");
1289 		break;
1290 	case CLOCK_TAI:
1291 		name = "tai\n";
1292 		sz = sizeof("tai\n");
1293 		break;
1294 	default:
1295 		BUG();
1296 	}
1297 
1298 	memcpy(buf, name, sz);
1299 	return sz;
1300 }
1301 
1302 static ssize_t iio_store_timestamp_clock(struct device *dev,
1303 					 struct device_attribute *attr,
1304 					 const char *buf, size_t len)
1305 {
1306 	clockid_t clk;
1307 	int ret;
1308 
1309 	if (sysfs_streq(buf, "realtime"))
1310 		clk = CLOCK_REALTIME;
1311 	else if (sysfs_streq(buf, "monotonic"))
1312 		clk = CLOCK_MONOTONIC;
1313 	else if (sysfs_streq(buf, "monotonic_raw"))
1314 		clk = CLOCK_MONOTONIC_RAW;
1315 	else if (sysfs_streq(buf, "realtime_coarse"))
1316 		clk = CLOCK_REALTIME_COARSE;
1317 	else if (sysfs_streq(buf, "monotonic_coarse"))
1318 		clk = CLOCK_MONOTONIC_COARSE;
1319 	else if (sysfs_streq(buf, "boottime"))
1320 		clk = CLOCK_BOOTTIME;
1321 	else if (sysfs_streq(buf, "tai"))
1322 		clk = CLOCK_TAI;
1323 	else
1324 		return -EINVAL;
1325 
1326 	ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1327 	if (ret)
1328 		return ret;
1329 
1330 	return len;
1331 }
1332 
1333 static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1334 		   iio_show_timestamp_clock, iio_store_timestamp_clock);
1335 
1336 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1337 {
1338 	int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1339 	struct iio_dev_attr *p;
1340 	struct attribute **attr, *clk = NULL;
1341 
1342 	/* First count elements in any existing group */
1343 	if (indio_dev->info->attrs) {
1344 		attr = indio_dev->info->attrs->attrs;
1345 		while (*attr++ != NULL)
1346 			attrcount_orig++;
1347 	}
1348 	attrcount = attrcount_orig;
1349 	/*
1350 	 * New channel registration method - relies on the fact a group does
1351 	 * not need to be initialized if its name is NULL.
1352 	 */
1353 	if (indio_dev->channels)
1354 		for (i = 0; i < indio_dev->num_channels; i++) {
1355 			const struct iio_chan_spec *chan =
1356 				&indio_dev->channels[i];
1357 
1358 			if (chan->type == IIO_TIMESTAMP)
1359 				clk = &dev_attr_current_timestamp_clock.attr;
1360 
1361 			ret = iio_device_add_channel_sysfs(indio_dev, chan);
1362 			if (ret < 0)
1363 				goto error_clear_attrs;
1364 			attrcount += ret;
1365 		}
1366 
1367 	if (indio_dev->event_interface)
1368 		clk = &dev_attr_current_timestamp_clock.attr;
1369 
1370 	if (indio_dev->name)
1371 		attrcount++;
1372 	if (clk)
1373 		attrcount++;
1374 
1375 	indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
1376 						   sizeof(indio_dev->chan_attr_group.attrs[0]),
1377 						   GFP_KERNEL);
1378 	if (indio_dev->chan_attr_group.attrs == NULL) {
1379 		ret = -ENOMEM;
1380 		goto error_clear_attrs;
1381 	}
1382 	/* Copy across original attributes */
1383 	if (indio_dev->info->attrs)
1384 		memcpy(indio_dev->chan_attr_group.attrs,
1385 		       indio_dev->info->attrs->attrs,
1386 		       sizeof(indio_dev->chan_attr_group.attrs[0])
1387 		       *attrcount_orig);
1388 	attrn = attrcount_orig;
1389 	/* Add all elements from the list. */
1390 	list_for_each_entry(p, &indio_dev->channel_attr_list, l)
1391 		indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1392 	if (indio_dev->name)
1393 		indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1394 	if (clk)
1395 		indio_dev->chan_attr_group.attrs[attrn++] = clk;
1396 
1397 	indio_dev->groups[indio_dev->groupcounter++] =
1398 		&indio_dev->chan_attr_group;
1399 
1400 	return 0;
1401 
1402 error_clear_attrs:
1403 	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1404 
1405 	return ret;
1406 }
1407 
1408 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1409 {
1410 
1411 	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1412 	kfree(indio_dev->chan_attr_group.attrs);
1413 	indio_dev->chan_attr_group.attrs = NULL;
1414 }
1415 
1416 static void iio_dev_release(struct device *device)
1417 {
1418 	struct iio_dev *indio_dev = dev_to_iio_dev(device);
1419 	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1420 		iio_device_unregister_trigger_consumer(indio_dev);
1421 	iio_device_unregister_eventset(indio_dev);
1422 	iio_device_unregister_sysfs(indio_dev);
1423 
1424 	iio_buffer_put(indio_dev->buffer);
1425 
1426 	ida_simple_remove(&iio_ida, indio_dev->id);
1427 	kfree(indio_dev);
1428 }
1429 
1430 struct device_type iio_device_type = {
1431 	.name = "iio_device",
1432 	.release = iio_dev_release,
1433 };
1434 
1435 /**
1436  * iio_device_alloc() - allocate an iio_dev from a driver
1437  * @sizeof_priv:	Space to allocate for private structure.
1438  **/
1439 struct iio_dev *iio_device_alloc(int sizeof_priv)
1440 {
1441 	struct iio_dev *dev;
1442 	size_t alloc_size;
1443 
1444 	alloc_size = sizeof(struct iio_dev);
1445 	if (sizeof_priv) {
1446 		alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1447 		alloc_size += sizeof_priv;
1448 	}
1449 	/* ensure 32-byte alignment of whole construct ? */
1450 	alloc_size += IIO_ALIGN - 1;
1451 
1452 	dev = kzalloc(alloc_size, GFP_KERNEL);
1453 
1454 	if (dev) {
1455 		dev->dev.groups = dev->groups;
1456 		dev->dev.type = &iio_device_type;
1457 		dev->dev.bus = &iio_bus_type;
1458 		device_initialize(&dev->dev);
1459 		dev_set_drvdata(&dev->dev, (void *)dev);
1460 		mutex_init(&dev->mlock);
1461 		mutex_init(&dev->info_exist_lock);
1462 		INIT_LIST_HEAD(&dev->channel_attr_list);
1463 
1464 		dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1465 		if (dev->id < 0) {
1466 			/* cannot use a dev_err as the name isn't available */
1467 			pr_err("failed to get device id\n");
1468 			kfree(dev);
1469 			return NULL;
1470 		}
1471 		dev_set_name(&dev->dev, "iio:device%d", dev->id);
1472 		INIT_LIST_HEAD(&dev->buffer_list);
1473 	}
1474 
1475 	return dev;
1476 }
1477 EXPORT_SYMBOL(iio_device_alloc);
1478 
1479 /**
1480  * iio_device_free() - free an iio_dev from a driver
1481  * @dev:		the iio_dev associated with the device
1482  **/
1483 void iio_device_free(struct iio_dev *dev)
1484 {
1485 	if (dev)
1486 		put_device(&dev->dev);
1487 }
1488 EXPORT_SYMBOL(iio_device_free);
1489 
1490 static void devm_iio_device_release(struct device *dev, void *res)
1491 {
1492 	iio_device_free(*(struct iio_dev **)res);
1493 }
1494 
1495 int devm_iio_device_match(struct device *dev, void *res, void *data)
1496 {
1497 	struct iio_dev **r = res;
1498 	if (!r || !*r) {
1499 		WARN_ON(!r || !*r);
1500 		return 0;
1501 	}
1502 	return *r == data;
1503 }
1504 EXPORT_SYMBOL_GPL(devm_iio_device_match);
1505 
1506 /**
1507  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1508  * @dev:		Device to allocate iio_dev for
1509  * @sizeof_priv:	Space to allocate for private structure.
1510  *
1511  * Managed iio_device_alloc. iio_dev allocated with this function is
1512  * automatically freed on driver detach.
1513  *
1514  * If an iio_dev allocated with this function needs to be freed separately,
1515  * devm_iio_device_free() must be used.
1516  *
1517  * RETURNS:
1518  * Pointer to allocated iio_dev on success, NULL on failure.
1519  */
1520 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1521 {
1522 	struct iio_dev **ptr, *iio_dev;
1523 
1524 	ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1525 			   GFP_KERNEL);
1526 	if (!ptr)
1527 		return NULL;
1528 
1529 	iio_dev = iio_device_alloc(sizeof_priv);
1530 	if (iio_dev) {
1531 		*ptr = iio_dev;
1532 		devres_add(dev, ptr);
1533 	} else {
1534 		devres_free(ptr);
1535 	}
1536 
1537 	return iio_dev;
1538 }
1539 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1540 
1541 /**
1542  * devm_iio_device_free - Resource-managed iio_device_free()
1543  * @dev:		Device this iio_dev belongs to
1544  * @iio_dev:		the iio_dev associated with the device
1545  *
1546  * Free iio_dev allocated with devm_iio_device_alloc().
1547  */
1548 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1549 {
1550 	int rc;
1551 
1552 	rc = devres_release(dev, devm_iio_device_release,
1553 			    devm_iio_device_match, iio_dev);
1554 	WARN_ON(rc);
1555 }
1556 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1557 
1558 /**
1559  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1560  * @inode:	Inode structure for identifying the device in the file system
1561  * @filp:	File structure for iio device used to keep and later access
1562  *		private data
1563  *
1564  * Return: 0 on success or -EBUSY if the device is already opened
1565  **/
1566 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1567 {
1568 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1569 						struct iio_dev, chrdev);
1570 
1571 	if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1572 		return -EBUSY;
1573 
1574 	iio_device_get(indio_dev);
1575 
1576 	filp->private_data = indio_dev;
1577 
1578 	return 0;
1579 }
1580 
1581 /**
1582  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1583  * @inode:	Inode structure pointer for the char device
1584  * @filp:	File structure pointer for the char device
1585  *
1586  * Return: 0 for successful release
1587  */
1588 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1589 {
1590 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1591 						struct iio_dev, chrdev);
1592 	clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1593 	iio_device_put(indio_dev);
1594 
1595 	return 0;
1596 }
1597 
1598 /* Somewhat of a cross file organization violation - ioctls here are actually
1599  * event related */
1600 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1601 {
1602 	struct iio_dev *indio_dev = filp->private_data;
1603 	int __user *ip = (int __user *)arg;
1604 	int fd;
1605 
1606 	if (!indio_dev->info)
1607 		return -ENODEV;
1608 
1609 	if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1610 		fd = iio_event_getfd(indio_dev);
1611 		if (fd < 0)
1612 			return fd;
1613 		if (copy_to_user(ip, &fd, sizeof(fd)))
1614 			return -EFAULT;
1615 		return 0;
1616 	}
1617 	return -EINVAL;
1618 }
1619 
1620 static const struct file_operations iio_buffer_fileops = {
1621 	.read = iio_buffer_read_first_n_outer_addr,
1622 	.release = iio_chrdev_release,
1623 	.open = iio_chrdev_open,
1624 	.poll = iio_buffer_poll_addr,
1625 	.owner = THIS_MODULE,
1626 	.llseek = noop_llseek,
1627 	.unlocked_ioctl = iio_ioctl,
1628 	.compat_ioctl = iio_ioctl,
1629 };
1630 
1631 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1632 {
1633 	int i, j;
1634 	const struct iio_chan_spec *channels = indio_dev->channels;
1635 
1636 	if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1637 		return 0;
1638 
1639 	for (i = 0; i < indio_dev->num_channels - 1; i++) {
1640 		if (channels[i].scan_index < 0)
1641 			continue;
1642 		for (j = i + 1; j < indio_dev->num_channels; j++)
1643 			if (channels[i].scan_index == channels[j].scan_index) {
1644 				dev_err(&indio_dev->dev,
1645 					"Duplicate scan index %d\n",
1646 					channels[i].scan_index);
1647 				return -EINVAL;
1648 			}
1649 	}
1650 
1651 	return 0;
1652 }
1653 
1654 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1655 
1656 int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1657 {
1658 	int ret;
1659 
1660 	indio_dev->driver_module = this_mod;
1661 	/* If the calling driver did not initialize of_node, do it here */
1662 	if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1663 		indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1664 
1665 	ret = iio_check_unique_scan_index(indio_dev);
1666 	if (ret < 0)
1667 		return ret;
1668 
1669 	if (!indio_dev->info)
1670 		return -EINVAL;
1671 
1672 	/* configure elements for the chrdev */
1673 	indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1674 
1675 	ret = iio_device_register_debugfs(indio_dev);
1676 	if (ret) {
1677 		dev_err(indio_dev->dev.parent,
1678 			"Failed to register debugfs interfaces\n");
1679 		return ret;
1680 	}
1681 
1682 	ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1683 	if (ret) {
1684 		dev_err(indio_dev->dev.parent,
1685 			"Failed to create buffer sysfs interfaces\n");
1686 		goto error_unreg_debugfs;
1687 	}
1688 
1689 	ret = iio_device_register_sysfs(indio_dev);
1690 	if (ret) {
1691 		dev_err(indio_dev->dev.parent,
1692 			"Failed to register sysfs interfaces\n");
1693 		goto error_buffer_free_sysfs;
1694 	}
1695 	ret = iio_device_register_eventset(indio_dev);
1696 	if (ret) {
1697 		dev_err(indio_dev->dev.parent,
1698 			"Failed to register event set\n");
1699 		goto error_free_sysfs;
1700 	}
1701 	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1702 		iio_device_register_trigger_consumer(indio_dev);
1703 
1704 	if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1705 		indio_dev->setup_ops == NULL)
1706 		indio_dev->setup_ops = &noop_ring_setup_ops;
1707 
1708 	cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1709 
1710 	indio_dev->chrdev.owner = this_mod;
1711 
1712 	ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev);
1713 	if (ret < 0)
1714 		goto error_unreg_eventset;
1715 
1716 	return 0;
1717 
1718 error_unreg_eventset:
1719 	iio_device_unregister_eventset(indio_dev);
1720 error_free_sysfs:
1721 	iio_device_unregister_sysfs(indio_dev);
1722 error_buffer_free_sysfs:
1723 	iio_buffer_free_sysfs_and_mask(indio_dev);
1724 error_unreg_debugfs:
1725 	iio_device_unregister_debugfs(indio_dev);
1726 	return ret;
1727 }
1728 EXPORT_SYMBOL(__iio_device_register);
1729 
1730 /**
1731  * iio_device_unregister() - unregister a device from the IIO subsystem
1732  * @indio_dev:		Device structure representing the device.
1733  **/
1734 void iio_device_unregister(struct iio_dev *indio_dev)
1735 {
1736 	cdev_device_del(&indio_dev->chrdev, &indio_dev->dev);
1737 
1738 	mutex_lock(&indio_dev->info_exist_lock);
1739 
1740 	iio_device_unregister_debugfs(indio_dev);
1741 
1742 	iio_disable_all_buffers(indio_dev);
1743 
1744 	indio_dev->info = NULL;
1745 
1746 	iio_device_wakeup_eventset(indio_dev);
1747 	iio_buffer_wakeup_poll(indio_dev);
1748 
1749 	mutex_unlock(&indio_dev->info_exist_lock);
1750 
1751 	iio_buffer_free_sysfs_and_mask(indio_dev);
1752 }
1753 EXPORT_SYMBOL(iio_device_unregister);
1754 
1755 static void devm_iio_device_unreg(struct device *dev, void *res)
1756 {
1757 	iio_device_unregister(*(struct iio_dev **)res);
1758 }
1759 
1760 int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
1761 			       struct module *this_mod)
1762 {
1763 	struct iio_dev **ptr;
1764 	int ret;
1765 
1766 	ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1767 	if (!ptr)
1768 		return -ENOMEM;
1769 
1770 	*ptr = indio_dev;
1771 	ret = __iio_device_register(indio_dev, this_mod);
1772 	if (!ret)
1773 		devres_add(dev, ptr);
1774 	else
1775 		devres_free(ptr);
1776 
1777 	return ret;
1778 }
1779 EXPORT_SYMBOL_GPL(__devm_iio_device_register);
1780 
1781 /**
1782  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1783  * @dev:	Device this iio_dev belongs to
1784  * @indio_dev:	the iio_dev associated with the device
1785  *
1786  * Unregister iio_dev registered with devm_iio_device_register().
1787  */
1788 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1789 {
1790 	int rc;
1791 
1792 	rc = devres_release(dev, devm_iio_device_unreg,
1793 			    devm_iio_device_match, indio_dev);
1794 	WARN_ON(rc);
1795 }
1796 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1797 
1798 /**
1799  * iio_device_claim_direct_mode - Keep device in direct mode
1800  * @indio_dev:	the iio_dev associated with the device
1801  *
1802  * If the device is in direct mode it is guaranteed to stay
1803  * that way until iio_device_release_direct_mode() is called.
1804  *
1805  * Use with iio_device_release_direct_mode()
1806  *
1807  * Returns: 0 on success, -EBUSY on failure
1808  */
1809 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1810 {
1811 	mutex_lock(&indio_dev->mlock);
1812 
1813 	if (iio_buffer_enabled(indio_dev)) {
1814 		mutex_unlock(&indio_dev->mlock);
1815 		return -EBUSY;
1816 	}
1817 	return 0;
1818 }
1819 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1820 
1821 /**
1822  * iio_device_release_direct_mode - releases claim on direct mode
1823  * @indio_dev:	the iio_dev associated with the device
1824  *
1825  * Release the claim. Device is no longer guaranteed to stay
1826  * in direct mode.
1827  *
1828  * Use with iio_device_claim_direct_mode()
1829  */
1830 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1831 {
1832 	mutex_unlock(&indio_dev->mlock);
1833 }
1834 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1835 
1836 subsys_initcall(iio_init);
1837 module_exit(iio_exit);
1838 
1839 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1840 MODULE_DESCRIPTION("Industrial I/O core");
1841 MODULE_LICENSE("GPL");
1842