1 /* The industrial I/O core
2  *
3  * Copyright (c) 2008 Jonathan Cameron
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 as published by
7  * the Free Software Foundation.
8  *
9  * Based on elements of hwmon and input subsystems.
10  */
11 
12 #define pr_fmt(fmt) "iio-core: " fmt
13 
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/idr.h>
17 #include <linux/kdev_t.h>
18 #include <linux/err.h>
19 #include <linux/device.h>
20 #include <linux/fs.h>
21 #include <linux/poll.h>
22 #include <linux/sched.h>
23 #include <linux/wait.h>
24 #include <linux/cdev.h>
25 #include <linux/slab.h>
26 #include <linux/anon_inodes.h>
27 #include <linux/debugfs.h>
28 #include <linux/mutex.h>
29 #include <linux/iio/iio.h>
30 #include "iio_core.h"
31 #include "iio_core_trigger.h"
32 #include <linux/iio/sysfs.h>
33 #include <linux/iio/events.h>
34 #include <linux/iio/buffer.h>
35 #include <linux/iio/buffer_impl.h>
36 
37 /* IDA to assign each registered device a unique id */
38 static DEFINE_IDA(iio_ida);
39 
40 static dev_t iio_devt;
41 
42 #define IIO_DEV_MAX 256
43 struct bus_type iio_bus_type = {
44 	.name = "iio",
45 };
46 EXPORT_SYMBOL(iio_bus_type);
47 
48 static struct dentry *iio_debugfs_dentry;
49 
50 static const char * const iio_direction[] = {
51 	[0] = "in",
52 	[1] = "out",
53 };
54 
55 static const char * const iio_chan_type_name_spec[] = {
56 	[IIO_VOLTAGE] = "voltage",
57 	[IIO_CURRENT] = "current",
58 	[IIO_POWER] = "power",
59 	[IIO_ACCEL] = "accel",
60 	[IIO_ANGL_VEL] = "anglvel",
61 	[IIO_MAGN] = "magn",
62 	[IIO_LIGHT] = "illuminance",
63 	[IIO_INTENSITY] = "intensity",
64 	[IIO_PROXIMITY] = "proximity",
65 	[IIO_TEMP] = "temp",
66 	[IIO_INCLI] = "incli",
67 	[IIO_ROT] = "rot",
68 	[IIO_ANGL] = "angl",
69 	[IIO_TIMESTAMP] = "timestamp",
70 	[IIO_CAPACITANCE] = "capacitance",
71 	[IIO_ALTVOLTAGE] = "altvoltage",
72 	[IIO_CCT] = "cct",
73 	[IIO_PRESSURE] = "pressure",
74 	[IIO_HUMIDITYRELATIVE] = "humidityrelative",
75 	[IIO_ACTIVITY] = "activity",
76 	[IIO_STEPS] = "steps",
77 	[IIO_ENERGY] = "energy",
78 	[IIO_DISTANCE] = "distance",
79 	[IIO_VELOCITY] = "velocity",
80 	[IIO_CONCENTRATION] = "concentration",
81 	[IIO_RESISTANCE] = "resistance",
82 	[IIO_PH] = "ph",
83 	[IIO_UVINDEX] = "uvindex",
84 	[IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
85 	[IIO_COUNT] = "count",
86 	[IIO_INDEX] = "index",
87 	[IIO_GRAVITY]  = "gravity",
88 };
89 
90 static const char * const iio_modifier_names[] = {
91 	[IIO_MOD_X] = "x",
92 	[IIO_MOD_Y] = "y",
93 	[IIO_MOD_Z] = "z",
94 	[IIO_MOD_X_AND_Y] = "x&y",
95 	[IIO_MOD_X_AND_Z] = "x&z",
96 	[IIO_MOD_Y_AND_Z] = "y&z",
97 	[IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
98 	[IIO_MOD_X_OR_Y] = "x|y",
99 	[IIO_MOD_X_OR_Z] = "x|z",
100 	[IIO_MOD_Y_OR_Z] = "y|z",
101 	[IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
102 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
103 	[IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
104 	[IIO_MOD_LIGHT_BOTH] = "both",
105 	[IIO_MOD_LIGHT_IR] = "ir",
106 	[IIO_MOD_LIGHT_CLEAR] = "clear",
107 	[IIO_MOD_LIGHT_RED] = "red",
108 	[IIO_MOD_LIGHT_GREEN] = "green",
109 	[IIO_MOD_LIGHT_BLUE] = "blue",
110 	[IIO_MOD_LIGHT_UV] = "uv",
111 	[IIO_MOD_QUATERNION] = "quaternion",
112 	[IIO_MOD_TEMP_AMBIENT] = "ambient",
113 	[IIO_MOD_TEMP_OBJECT] = "object",
114 	[IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
115 	[IIO_MOD_NORTH_TRUE] = "from_north_true",
116 	[IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
117 	[IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
118 	[IIO_MOD_RUNNING] = "running",
119 	[IIO_MOD_JOGGING] = "jogging",
120 	[IIO_MOD_WALKING] = "walking",
121 	[IIO_MOD_STILL] = "still",
122 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
123 	[IIO_MOD_I] = "i",
124 	[IIO_MOD_Q] = "q",
125 	[IIO_MOD_CO2] = "co2",
126 	[IIO_MOD_VOC] = "voc",
127 };
128 
129 /* relies on pairs of these shared then separate */
130 static const char * const iio_chan_info_postfix[] = {
131 	[IIO_CHAN_INFO_RAW] = "raw",
132 	[IIO_CHAN_INFO_PROCESSED] = "input",
133 	[IIO_CHAN_INFO_SCALE] = "scale",
134 	[IIO_CHAN_INFO_OFFSET] = "offset",
135 	[IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
136 	[IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
137 	[IIO_CHAN_INFO_PEAK] = "peak_raw",
138 	[IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
139 	[IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
140 	[IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
141 	[IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
142 	= "filter_low_pass_3db_frequency",
143 	[IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
144 	= "filter_high_pass_3db_frequency",
145 	[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
146 	[IIO_CHAN_INFO_FREQUENCY] = "frequency",
147 	[IIO_CHAN_INFO_PHASE] = "phase",
148 	[IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
149 	[IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
150 	[IIO_CHAN_INFO_INT_TIME] = "integration_time",
151 	[IIO_CHAN_INFO_ENABLE] = "en",
152 	[IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
153 	[IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
154 	[IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
155 	[IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
156 	[IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
157 	[IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
158 };
159 
160 /**
161  * iio_find_channel_from_si() - get channel from its scan index
162  * @indio_dev:		device
163  * @si:			scan index to match
164  */
165 const struct iio_chan_spec
166 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
167 {
168 	int i;
169 
170 	for (i = 0; i < indio_dev->num_channels; i++)
171 		if (indio_dev->channels[i].scan_index == si)
172 			return &indio_dev->channels[i];
173 	return NULL;
174 }
175 
176 /* This turns up an awful lot */
177 ssize_t iio_read_const_attr(struct device *dev,
178 			    struct device_attribute *attr,
179 			    char *buf)
180 {
181 	return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
182 }
183 EXPORT_SYMBOL(iio_read_const_attr);
184 
185 static int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
186 {
187 	int ret;
188 	const struct iio_event_interface *ev_int = indio_dev->event_interface;
189 
190 	ret = mutex_lock_interruptible(&indio_dev->mlock);
191 	if (ret)
192 		return ret;
193 	if ((ev_int && iio_event_enabled(ev_int)) ||
194 	    iio_buffer_enabled(indio_dev)) {
195 		mutex_unlock(&indio_dev->mlock);
196 		return -EBUSY;
197 	}
198 	indio_dev->clock_id = clock_id;
199 	mutex_unlock(&indio_dev->mlock);
200 
201 	return 0;
202 }
203 
204 /**
205  * iio_get_time_ns() - utility function to get a time stamp for events etc
206  * @indio_dev: device
207  */
208 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
209 {
210 	struct timespec tp;
211 
212 	switch (iio_device_get_clock(indio_dev)) {
213 	case CLOCK_REALTIME:
214 		ktime_get_real_ts(&tp);
215 		break;
216 	case CLOCK_MONOTONIC:
217 		ktime_get_ts(&tp);
218 		break;
219 	case CLOCK_MONOTONIC_RAW:
220 		getrawmonotonic(&tp);
221 		break;
222 	case CLOCK_REALTIME_COARSE:
223 		tp = current_kernel_time();
224 		break;
225 	case CLOCK_MONOTONIC_COARSE:
226 		tp = get_monotonic_coarse();
227 		break;
228 	case CLOCK_BOOTTIME:
229 		get_monotonic_boottime(&tp);
230 		break;
231 	case CLOCK_TAI:
232 		timekeeping_clocktai(&tp);
233 		break;
234 	default:
235 		BUG();
236 	}
237 
238 	return timespec_to_ns(&tp);
239 }
240 EXPORT_SYMBOL(iio_get_time_ns);
241 
242 /**
243  * iio_get_time_res() - utility function to get time stamp clock resolution in
244  *                      nano seconds.
245  * @indio_dev: device
246  */
247 unsigned int iio_get_time_res(const struct iio_dev *indio_dev)
248 {
249 	switch (iio_device_get_clock(indio_dev)) {
250 	case CLOCK_REALTIME:
251 	case CLOCK_MONOTONIC:
252 	case CLOCK_MONOTONIC_RAW:
253 	case CLOCK_BOOTTIME:
254 	case CLOCK_TAI:
255 		return hrtimer_resolution;
256 	case CLOCK_REALTIME_COARSE:
257 	case CLOCK_MONOTONIC_COARSE:
258 		return LOW_RES_NSEC;
259 	default:
260 		BUG();
261 	}
262 }
263 EXPORT_SYMBOL(iio_get_time_res);
264 
265 static int __init iio_init(void)
266 {
267 	int ret;
268 
269 	/* Register sysfs bus */
270 	ret  = bus_register(&iio_bus_type);
271 	if (ret < 0) {
272 		pr_err("could not register bus type\n");
273 		goto error_nothing;
274 	}
275 
276 	ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
277 	if (ret < 0) {
278 		pr_err("failed to allocate char dev region\n");
279 		goto error_unregister_bus_type;
280 	}
281 
282 	iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
283 
284 	return 0;
285 
286 error_unregister_bus_type:
287 	bus_unregister(&iio_bus_type);
288 error_nothing:
289 	return ret;
290 }
291 
292 static void __exit iio_exit(void)
293 {
294 	if (iio_devt)
295 		unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
296 	bus_unregister(&iio_bus_type);
297 	debugfs_remove(iio_debugfs_dentry);
298 }
299 
300 #if defined(CONFIG_DEBUG_FS)
301 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
302 			      size_t count, loff_t *ppos)
303 {
304 	struct iio_dev *indio_dev = file->private_data;
305 	char buf[20];
306 	unsigned val = 0;
307 	ssize_t len;
308 	int ret;
309 
310 	ret = indio_dev->info->debugfs_reg_access(indio_dev,
311 						  indio_dev->cached_reg_addr,
312 						  0, &val);
313 	if (ret)
314 		dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
315 
316 	len = snprintf(buf, sizeof(buf), "0x%X\n", val);
317 
318 	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
319 }
320 
321 static 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 
358 static 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 
364 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
365 {
366 	debugfs_remove_recursive(indio_dev->debugfs_dentry);
367 }
368 
369 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
370 {
371 	struct dentry *d;
372 
373 	if (indio_dev->info->debugfs_reg_access == NULL)
374 		return 0;
375 
376 	if (!iio_debugfs_dentry)
377 		return 0;
378 
379 	indio_dev->debugfs_dentry =
380 		debugfs_create_dir(dev_name(&indio_dev->dev),
381 				   iio_debugfs_dentry);
382 	if (indio_dev->debugfs_dentry == NULL) {
383 		dev_warn(indio_dev->dev.parent,
384 			 "Failed to create debugfs directory\n");
385 		return -EFAULT;
386 	}
387 
388 	d = debugfs_create_file("direct_reg_access", 0644,
389 				indio_dev->debugfs_dentry,
390 				indio_dev, &iio_debugfs_reg_fops);
391 	if (!d) {
392 		iio_device_unregister_debugfs(indio_dev);
393 		return -ENOMEM;
394 	}
395 
396 	return 0;
397 }
398 #else
399 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
400 {
401 	return 0;
402 }
403 
404 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
405 {
406 }
407 #endif /* CONFIG_DEBUG_FS */
408 
409 static ssize_t iio_read_channel_ext_info(struct device *dev,
410 				     struct device_attribute *attr,
411 				     char *buf)
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->read(indio_dev, ext_info->private, this_attr->c, buf);
420 }
421 
422 static ssize_t iio_write_channel_ext_info(struct device *dev,
423 				     struct device_attribute *attr,
424 				     const char *buf,
425 					 size_t len)
426 {
427 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
428 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
429 	const struct iio_chan_spec_ext_info *ext_info;
430 
431 	ext_info = &this_attr->c->ext_info[this_attr->address];
432 
433 	return ext_info->write(indio_dev, ext_info->private,
434 			       this_attr->c, buf, len);
435 }
436 
437 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
438 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
439 {
440 	const struct iio_enum *e = (const struct iio_enum *)priv;
441 	unsigned int i;
442 	size_t len = 0;
443 
444 	if (!e->num_items)
445 		return 0;
446 
447 	for (i = 0; i < e->num_items; ++i)
448 		len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
449 
450 	/* replace last space with a newline */
451 	buf[len - 1] = '\n';
452 
453 	return len;
454 }
455 EXPORT_SYMBOL_GPL(iio_enum_available_read);
456 
457 ssize_t iio_enum_read(struct iio_dev *indio_dev,
458 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
459 {
460 	const struct iio_enum *e = (const struct iio_enum *)priv;
461 	int i;
462 
463 	if (!e->get)
464 		return -EINVAL;
465 
466 	i = e->get(indio_dev, chan);
467 	if (i < 0)
468 		return i;
469 	else if (i >= e->num_items)
470 		return -EINVAL;
471 
472 	return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
473 }
474 EXPORT_SYMBOL_GPL(iio_enum_read);
475 
476 ssize_t iio_enum_write(struct iio_dev *indio_dev,
477 	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
478 	size_t len)
479 {
480 	const struct iio_enum *e = (const struct iio_enum *)priv;
481 	unsigned int i;
482 	int ret;
483 
484 	if (!e->set)
485 		return -EINVAL;
486 
487 	for (i = 0; i < e->num_items; i++) {
488 		if (sysfs_streq(buf, e->items[i]))
489 			break;
490 	}
491 
492 	if (i == e->num_items)
493 		return -EINVAL;
494 
495 	ret = e->set(indio_dev, chan, i);
496 	return ret ? ret : len;
497 }
498 EXPORT_SYMBOL_GPL(iio_enum_write);
499 
500 static const struct iio_mount_matrix iio_mount_idmatrix = {
501 	.rotation = {
502 		"1", "0", "0",
503 		"0", "1", "0",
504 		"0", "0", "1"
505 	}
506 };
507 
508 static int iio_setup_mount_idmatrix(const struct device *dev,
509 				    struct iio_mount_matrix *matrix)
510 {
511 	*matrix = iio_mount_idmatrix;
512 	dev_info(dev, "mounting matrix not found: using identity...\n");
513 	return 0;
514 }
515 
516 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
517 			      const struct iio_chan_spec *chan, char *buf)
518 {
519 	const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
520 					      priv)(indio_dev, chan);
521 
522 	if (IS_ERR(mtx))
523 		return PTR_ERR(mtx);
524 
525 	if (!mtx)
526 		mtx = &iio_mount_idmatrix;
527 
528 	return snprintf(buf, PAGE_SIZE, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
529 			mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
530 			mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
531 			mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
532 }
533 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
534 
535 /**
536  * of_iio_read_mount_matrix() - retrieve iio device mounting matrix from
537  *                              device-tree "mount-matrix" property
538  * @dev:	device the mounting matrix property is assigned to
539  * @propname:	device specific mounting matrix property name
540  * @matrix:	where to store retrieved matrix
541  *
542  * If device is assigned no mounting matrix property, a default 3x3 identity
543  * matrix will be filled in.
544  *
545  * Return: 0 if success, or a negative error code on failure.
546  */
547 #ifdef CONFIG_OF
548 int of_iio_read_mount_matrix(const struct device *dev,
549 			     const char *propname,
550 			     struct iio_mount_matrix *matrix)
551 {
552 	if (dev->of_node) {
553 		int err = of_property_read_string_array(dev->of_node,
554 				propname, matrix->rotation,
555 				ARRAY_SIZE(iio_mount_idmatrix.rotation));
556 
557 		if (err == ARRAY_SIZE(iio_mount_idmatrix.rotation))
558 			return 0;
559 
560 		if (err >= 0)
561 			/* Invalid number of matrix entries. */
562 			return -EINVAL;
563 
564 		if (err != -EINVAL)
565 			/* Invalid matrix declaration format. */
566 			return err;
567 	}
568 
569 	/* Matrix was not declared at all: fallback to identity. */
570 	return iio_setup_mount_idmatrix(dev, matrix);
571 }
572 #else
573 int of_iio_read_mount_matrix(const struct device *dev,
574 			     const char *propname,
575 			     struct iio_mount_matrix *matrix)
576 {
577 	return iio_setup_mount_idmatrix(dev, matrix);
578 }
579 #endif
580 EXPORT_SYMBOL(of_iio_read_mount_matrix);
581 
582 static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
583 				  int size, const int *vals)
584 {
585 	unsigned long long tmp;
586 	int tmp0, tmp1;
587 	bool scale_db = false;
588 
589 	switch (type) {
590 	case IIO_VAL_INT:
591 		return snprintf(buf, len, "%d", vals[0]);
592 	case IIO_VAL_INT_PLUS_MICRO_DB:
593 		scale_db = true;
594 	case IIO_VAL_INT_PLUS_MICRO:
595 		if (vals[1] < 0)
596 			return snprintf(buf, len, "-%d.%06u%s", abs(vals[0]),
597 					-vals[1], scale_db ? " dB" : "");
598 		else
599 			return snprintf(buf, len, "%d.%06u%s", vals[0], vals[1],
600 					scale_db ? " dB" : "");
601 	case IIO_VAL_INT_PLUS_NANO:
602 		if (vals[1] < 0)
603 			return snprintf(buf, len, "-%d.%09u", abs(vals[0]),
604 					-vals[1]);
605 		else
606 			return snprintf(buf, len, "%d.%09u", vals[0], vals[1]);
607 	case IIO_VAL_FRACTIONAL:
608 		tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
609 		tmp1 = vals[1];
610 		tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1);
611 		return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
612 	case IIO_VAL_FRACTIONAL_LOG2:
613 		tmp = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
614 		tmp0 = (int)div_s64_rem(tmp, 1000000000LL, &tmp1);
615 		return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
616 	case IIO_VAL_INT_MULTIPLE:
617 	{
618 		int i;
619 		int l = 0;
620 
621 		for (i = 0; i < size; ++i) {
622 			l += snprintf(&buf[l], len - l, "%d ", vals[i]);
623 			if (l >= len)
624 				break;
625 		}
626 		return l;
627 	}
628 	default:
629 		return 0;
630 	}
631 }
632 
633 /**
634  * iio_format_value() - Formats a IIO value into its string representation
635  * @buf:	The buffer to which the formatted value gets written
636  *		which is assumed to be big enough (i.e. PAGE_SIZE).
637  * @type:	One of the IIO_VAL_... constants. This decides how the val
638  *		and val2 parameters are formatted.
639  * @size:	Number of IIO value entries contained in vals
640  * @vals:	Pointer to the values, exact meaning depends on the
641  *		type parameter.
642  *
643  * Return: 0 by default, a negative number on failure or the
644  *	   total number of characters written for a type that belongs
645  *	   to the IIO_VAL_... constant.
646  */
647 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
648 {
649 	ssize_t len;
650 
651 	len = __iio_format_value(buf, PAGE_SIZE, type, size, vals);
652 	if (len >= PAGE_SIZE - 1)
653 		return -EFBIG;
654 
655 	return len + sprintf(buf + len, "\n");
656 }
657 EXPORT_SYMBOL_GPL(iio_format_value);
658 
659 static ssize_t iio_read_channel_info(struct device *dev,
660 				     struct device_attribute *attr,
661 				     char *buf)
662 {
663 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
664 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
665 	int vals[INDIO_MAX_RAW_ELEMENTS];
666 	int ret;
667 	int val_len = 2;
668 
669 	if (indio_dev->info->read_raw_multi)
670 		ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
671 							INDIO_MAX_RAW_ELEMENTS,
672 							vals, &val_len,
673 							this_attr->address);
674 	else
675 		ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
676 				    &vals[0], &vals[1], this_attr->address);
677 
678 	if (ret < 0)
679 		return ret;
680 
681 	return iio_format_value(buf, ret, val_len, vals);
682 }
683 
684 static ssize_t iio_format_avail_list(char *buf, const int *vals,
685 				     int type, int length)
686 {
687 	int i;
688 	ssize_t len = 0;
689 
690 	switch (type) {
691 	case IIO_VAL_INT:
692 		for (i = 0; i < length; i++) {
693 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
694 						  type, 1, &vals[i]);
695 			if (len >= PAGE_SIZE)
696 				return -EFBIG;
697 			if (i < length - 1)
698 				len += snprintf(buf + len, PAGE_SIZE - len,
699 						" ");
700 			else
701 				len += snprintf(buf + len, PAGE_SIZE - len,
702 						"\n");
703 			if (len >= PAGE_SIZE)
704 				return -EFBIG;
705 		}
706 		break;
707 	default:
708 		for (i = 0; i < length / 2; i++) {
709 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
710 						  type, 2, &vals[i * 2]);
711 			if (len >= PAGE_SIZE)
712 				return -EFBIG;
713 			if (i < length / 2 - 1)
714 				len += snprintf(buf + len, PAGE_SIZE - len,
715 						" ");
716 			else
717 				len += snprintf(buf + len, PAGE_SIZE - len,
718 						"\n");
719 			if (len >= PAGE_SIZE)
720 				return -EFBIG;
721 		}
722 	}
723 
724 	return len;
725 }
726 
727 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
728 {
729 	int i;
730 	ssize_t len;
731 
732 	len = snprintf(buf, PAGE_SIZE, "[");
733 	switch (type) {
734 	case IIO_VAL_INT:
735 		for (i = 0; i < 3; i++) {
736 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
737 						  type, 1, &vals[i]);
738 			if (len >= PAGE_SIZE)
739 				return -EFBIG;
740 			if (i < 2)
741 				len += snprintf(buf + len, PAGE_SIZE - len,
742 						" ");
743 			else
744 				len += snprintf(buf + len, PAGE_SIZE - len,
745 						"]\n");
746 			if (len >= PAGE_SIZE)
747 				return -EFBIG;
748 		}
749 		break;
750 	default:
751 		for (i = 0; i < 3; i++) {
752 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
753 						  type, 2, &vals[i * 2]);
754 			if (len >= PAGE_SIZE)
755 				return -EFBIG;
756 			if (i < 2)
757 				len += snprintf(buf + len, PAGE_SIZE - len,
758 						" ");
759 			else
760 				len += snprintf(buf + len, PAGE_SIZE - len,
761 						"]\n");
762 			if (len >= PAGE_SIZE)
763 				return -EFBIG;
764 		}
765 	}
766 
767 	return len;
768 }
769 
770 static ssize_t iio_read_channel_info_avail(struct device *dev,
771 					   struct device_attribute *attr,
772 					   char *buf)
773 {
774 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
775 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
776 	const int *vals;
777 	int ret;
778 	int length;
779 	int type;
780 
781 	ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
782 					  &vals, &type, &length,
783 					  this_attr->address);
784 
785 	if (ret < 0)
786 		return ret;
787 	switch (ret) {
788 	case IIO_AVAIL_LIST:
789 		return iio_format_avail_list(buf, vals, type, length);
790 	case IIO_AVAIL_RANGE:
791 		return iio_format_avail_range(buf, vals, type);
792 	default:
793 		return -EINVAL;
794 	}
795 }
796 
797 /**
798  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
799  * @str: The string to parse
800  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
801  * @integer: The integer part of the number
802  * @fract: The fractional part of the number
803  *
804  * Returns 0 on success, or a negative error code if the string could not be
805  * parsed.
806  */
807 int iio_str_to_fixpoint(const char *str, int fract_mult,
808 	int *integer, int *fract)
809 {
810 	int i = 0, f = 0;
811 	bool integer_part = true, negative = false;
812 
813 	if (fract_mult == 0) {
814 		*fract = 0;
815 
816 		return kstrtoint(str, 0, integer);
817 	}
818 
819 	if (str[0] == '-') {
820 		negative = true;
821 		str++;
822 	} else if (str[0] == '+') {
823 		str++;
824 	}
825 
826 	while (*str) {
827 		if ('0' <= *str && *str <= '9') {
828 			if (integer_part) {
829 				i = i * 10 + *str - '0';
830 			} else {
831 				f += fract_mult * (*str - '0');
832 				fract_mult /= 10;
833 			}
834 		} else if (*str == '\n') {
835 			if (*(str + 1) == '\0')
836 				break;
837 			else
838 				return -EINVAL;
839 		} else if (*str == '.' && integer_part) {
840 			integer_part = false;
841 		} else {
842 			return -EINVAL;
843 		}
844 		str++;
845 	}
846 
847 	if (negative) {
848 		if (i)
849 			i = -i;
850 		else
851 			f = -f;
852 	}
853 
854 	*integer = i;
855 	*fract = f;
856 
857 	return 0;
858 }
859 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
860 
861 static ssize_t iio_write_channel_info(struct device *dev,
862 				      struct device_attribute *attr,
863 				      const char *buf,
864 				      size_t len)
865 {
866 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
867 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
868 	int ret, fract_mult = 100000;
869 	int integer, fract;
870 
871 	/* Assumes decimal - precision based on number of digits */
872 	if (!indio_dev->info->write_raw)
873 		return -EINVAL;
874 
875 	if (indio_dev->info->write_raw_get_fmt)
876 		switch (indio_dev->info->write_raw_get_fmt(indio_dev,
877 			this_attr->c, this_attr->address)) {
878 		case IIO_VAL_INT:
879 			fract_mult = 0;
880 			break;
881 		case IIO_VAL_INT_PLUS_MICRO:
882 			fract_mult = 100000;
883 			break;
884 		case IIO_VAL_INT_PLUS_NANO:
885 			fract_mult = 100000000;
886 			break;
887 		default:
888 			return -EINVAL;
889 		}
890 
891 	ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
892 	if (ret)
893 		return ret;
894 
895 	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
896 					 integer, fract, this_attr->address);
897 	if (ret)
898 		return ret;
899 
900 	return len;
901 }
902 
903 static
904 int __iio_device_attr_init(struct device_attribute *dev_attr,
905 			   const char *postfix,
906 			   struct iio_chan_spec const *chan,
907 			   ssize_t (*readfunc)(struct device *dev,
908 					       struct device_attribute *attr,
909 					       char *buf),
910 			   ssize_t (*writefunc)(struct device *dev,
911 						struct device_attribute *attr,
912 						const char *buf,
913 						size_t len),
914 			   enum iio_shared_by shared_by)
915 {
916 	int ret = 0;
917 	char *name = NULL;
918 	char *full_postfix;
919 	sysfs_attr_init(&dev_attr->attr);
920 
921 	/* Build up postfix of <extend_name>_<modifier>_postfix */
922 	if (chan->modified && (shared_by == IIO_SEPARATE)) {
923 		if (chan->extend_name)
924 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
925 						 iio_modifier_names[chan
926 								    ->channel2],
927 						 chan->extend_name,
928 						 postfix);
929 		else
930 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
931 						 iio_modifier_names[chan
932 								    ->channel2],
933 						 postfix);
934 	} else {
935 		if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
936 			full_postfix = kstrdup(postfix, GFP_KERNEL);
937 		else
938 			full_postfix = kasprintf(GFP_KERNEL,
939 						 "%s_%s",
940 						 chan->extend_name,
941 						 postfix);
942 	}
943 	if (full_postfix == NULL)
944 		return -ENOMEM;
945 
946 	if (chan->differential) { /* Differential can not have modifier */
947 		switch (shared_by) {
948 		case IIO_SHARED_BY_ALL:
949 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
950 			break;
951 		case IIO_SHARED_BY_DIR:
952 			name = kasprintf(GFP_KERNEL, "%s_%s",
953 						iio_direction[chan->output],
954 						full_postfix);
955 			break;
956 		case IIO_SHARED_BY_TYPE:
957 			name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
958 					    iio_direction[chan->output],
959 					    iio_chan_type_name_spec[chan->type],
960 					    iio_chan_type_name_spec[chan->type],
961 					    full_postfix);
962 			break;
963 		case IIO_SEPARATE:
964 			if (!chan->indexed) {
965 				WARN(1, "Differential channels must be indexed\n");
966 				ret = -EINVAL;
967 				goto error_free_full_postfix;
968 			}
969 			name = kasprintf(GFP_KERNEL,
970 					    "%s_%s%d-%s%d_%s",
971 					    iio_direction[chan->output],
972 					    iio_chan_type_name_spec[chan->type],
973 					    chan->channel,
974 					    iio_chan_type_name_spec[chan->type],
975 					    chan->channel2,
976 					    full_postfix);
977 			break;
978 		}
979 	} else { /* Single ended */
980 		switch (shared_by) {
981 		case IIO_SHARED_BY_ALL:
982 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
983 			break;
984 		case IIO_SHARED_BY_DIR:
985 			name = kasprintf(GFP_KERNEL, "%s_%s",
986 						iio_direction[chan->output],
987 						full_postfix);
988 			break;
989 		case IIO_SHARED_BY_TYPE:
990 			name = kasprintf(GFP_KERNEL, "%s_%s_%s",
991 					    iio_direction[chan->output],
992 					    iio_chan_type_name_spec[chan->type],
993 					    full_postfix);
994 			break;
995 
996 		case IIO_SEPARATE:
997 			if (chan->indexed)
998 				name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
999 						    iio_direction[chan->output],
1000 						    iio_chan_type_name_spec[chan->type],
1001 						    chan->channel,
1002 						    full_postfix);
1003 			else
1004 				name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1005 						    iio_direction[chan->output],
1006 						    iio_chan_type_name_spec[chan->type],
1007 						    full_postfix);
1008 			break;
1009 		}
1010 	}
1011 	if (name == NULL) {
1012 		ret = -ENOMEM;
1013 		goto error_free_full_postfix;
1014 	}
1015 	dev_attr->attr.name = name;
1016 
1017 	if (readfunc) {
1018 		dev_attr->attr.mode |= S_IRUGO;
1019 		dev_attr->show = readfunc;
1020 	}
1021 
1022 	if (writefunc) {
1023 		dev_attr->attr.mode |= S_IWUSR;
1024 		dev_attr->store = writefunc;
1025 	}
1026 
1027 error_free_full_postfix:
1028 	kfree(full_postfix);
1029 
1030 	return ret;
1031 }
1032 
1033 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1034 {
1035 	kfree(dev_attr->attr.name);
1036 }
1037 
1038 int __iio_add_chan_devattr(const char *postfix,
1039 			   struct iio_chan_spec const *chan,
1040 			   ssize_t (*readfunc)(struct device *dev,
1041 					       struct device_attribute *attr,
1042 					       char *buf),
1043 			   ssize_t (*writefunc)(struct device *dev,
1044 						struct device_attribute *attr,
1045 						const char *buf,
1046 						size_t len),
1047 			   u64 mask,
1048 			   enum iio_shared_by shared_by,
1049 			   struct device *dev,
1050 			   struct list_head *attr_list)
1051 {
1052 	int ret;
1053 	struct iio_dev_attr *iio_attr, *t;
1054 
1055 	iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1056 	if (iio_attr == NULL)
1057 		return -ENOMEM;
1058 	ret = __iio_device_attr_init(&iio_attr->dev_attr,
1059 				     postfix, chan,
1060 				     readfunc, writefunc, shared_by);
1061 	if (ret)
1062 		goto error_iio_dev_attr_free;
1063 	iio_attr->c = chan;
1064 	iio_attr->address = mask;
1065 	list_for_each_entry(t, attr_list, l)
1066 		if (strcmp(t->dev_attr.attr.name,
1067 			   iio_attr->dev_attr.attr.name) == 0) {
1068 			if (shared_by == IIO_SEPARATE)
1069 				dev_err(dev, "tried to double register : %s\n",
1070 					t->dev_attr.attr.name);
1071 			ret = -EBUSY;
1072 			goto error_device_attr_deinit;
1073 		}
1074 	list_add(&iio_attr->l, attr_list);
1075 
1076 	return 0;
1077 
1078 error_device_attr_deinit:
1079 	__iio_device_attr_deinit(&iio_attr->dev_attr);
1080 error_iio_dev_attr_free:
1081 	kfree(iio_attr);
1082 	return ret;
1083 }
1084 
1085 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1086 					 struct iio_chan_spec const *chan,
1087 					 enum iio_shared_by shared_by,
1088 					 const long *infomask)
1089 {
1090 	int i, ret, attrcount = 0;
1091 
1092 	for_each_set_bit(i, infomask, sizeof(infomask)*8) {
1093 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1094 			return -EINVAL;
1095 		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1096 					     chan,
1097 					     &iio_read_channel_info,
1098 					     &iio_write_channel_info,
1099 					     i,
1100 					     shared_by,
1101 					     &indio_dev->dev,
1102 					     &indio_dev->channel_attr_list);
1103 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1104 			continue;
1105 		else if (ret < 0)
1106 			return ret;
1107 		attrcount++;
1108 	}
1109 
1110 	return attrcount;
1111 }
1112 
1113 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1114 					       struct iio_chan_spec const *chan,
1115 					       enum iio_shared_by shared_by,
1116 					       const long *infomask)
1117 {
1118 	int i, ret, attrcount = 0;
1119 	char *avail_postfix;
1120 
1121 	for_each_set_bit(i, infomask, sizeof(infomask) * 8) {
1122 		avail_postfix = kasprintf(GFP_KERNEL,
1123 					  "%s_available",
1124 					  iio_chan_info_postfix[i]);
1125 		if (!avail_postfix)
1126 			return -ENOMEM;
1127 
1128 		ret = __iio_add_chan_devattr(avail_postfix,
1129 					     chan,
1130 					     &iio_read_channel_info_avail,
1131 					     NULL,
1132 					     i,
1133 					     shared_by,
1134 					     &indio_dev->dev,
1135 					     &indio_dev->channel_attr_list);
1136 		kfree(avail_postfix);
1137 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1138 			continue;
1139 		else if (ret < 0)
1140 			return ret;
1141 		attrcount++;
1142 	}
1143 
1144 	return attrcount;
1145 }
1146 
1147 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1148 					struct iio_chan_spec const *chan)
1149 {
1150 	int ret, attrcount = 0;
1151 	const struct iio_chan_spec_ext_info *ext_info;
1152 
1153 	if (chan->channel < 0)
1154 		return 0;
1155 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1156 					    IIO_SEPARATE,
1157 					    &chan->info_mask_separate);
1158 	if (ret < 0)
1159 		return ret;
1160 	attrcount += ret;
1161 
1162 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1163 						  IIO_SEPARATE,
1164 						  &chan->
1165 						  info_mask_separate_available);
1166 	if (ret < 0)
1167 		return ret;
1168 	attrcount += ret;
1169 
1170 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1171 					    IIO_SHARED_BY_TYPE,
1172 					    &chan->info_mask_shared_by_type);
1173 	if (ret < 0)
1174 		return ret;
1175 	attrcount += ret;
1176 
1177 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1178 						  IIO_SHARED_BY_TYPE,
1179 						  &chan->
1180 						  info_mask_shared_by_type_available);
1181 	if (ret < 0)
1182 		return ret;
1183 	attrcount += ret;
1184 
1185 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1186 					    IIO_SHARED_BY_DIR,
1187 					    &chan->info_mask_shared_by_dir);
1188 	if (ret < 0)
1189 		return ret;
1190 	attrcount += ret;
1191 
1192 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1193 						  IIO_SHARED_BY_DIR,
1194 						  &chan->info_mask_shared_by_dir_available);
1195 	if (ret < 0)
1196 		return ret;
1197 	attrcount += ret;
1198 
1199 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1200 					    IIO_SHARED_BY_ALL,
1201 					    &chan->info_mask_shared_by_all);
1202 	if (ret < 0)
1203 		return ret;
1204 	attrcount += ret;
1205 
1206 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1207 						  IIO_SHARED_BY_ALL,
1208 						  &chan->info_mask_shared_by_all_available);
1209 	if (ret < 0)
1210 		return ret;
1211 	attrcount += ret;
1212 
1213 	if (chan->ext_info) {
1214 		unsigned int i = 0;
1215 		for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1216 			ret = __iio_add_chan_devattr(ext_info->name,
1217 					chan,
1218 					ext_info->read ?
1219 					    &iio_read_channel_ext_info : NULL,
1220 					ext_info->write ?
1221 					    &iio_write_channel_ext_info : NULL,
1222 					i,
1223 					ext_info->shared,
1224 					&indio_dev->dev,
1225 					&indio_dev->channel_attr_list);
1226 			i++;
1227 			if (ret == -EBUSY && ext_info->shared)
1228 				continue;
1229 
1230 			if (ret)
1231 				return ret;
1232 
1233 			attrcount++;
1234 		}
1235 	}
1236 
1237 	return attrcount;
1238 }
1239 
1240 /**
1241  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1242  * @attr_list: List of IIO device attributes
1243  *
1244  * This function frees the memory allocated for each of the IIO device
1245  * attributes in the list.
1246  */
1247 void iio_free_chan_devattr_list(struct list_head *attr_list)
1248 {
1249 	struct iio_dev_attr *p, *n;
1250 
1251 	list_for_each_entry_safe(p, n, attr_list, l) {
1252 		kfree(p->dev_attr.attr.name);
1253 		list_del(&p->l);
1254 		kfree(p);
1255 	}
1256 }
1257 
1258 static ssize_t iio_show_dev_name(struct device *dev,
1259 				 struct device_attribute *attr,
1260 				 char *buf)
1261 {
1262 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1263 	return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
1264 }
1265 
1266 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
1267 
1268 static ssize_t iio_show_timestamp_clock(struct device *dev,
1269 					struct device_attribute *attr,
1270 					char *buf)
1271 {
1272 	const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1273 	const clockid_t clk = iio_device_get_clock(indio_dev);
1274 	const char *name;
1275 	ssize_t sz;
1276 
1277 	switch (clk) {
1278 	case CLOCK_REALTIME:
1279 		name = "realtime\n";
1280 		sz = sizeof("realtime\n");
1281 		break;
1282 	case CLOCK_MONOTONIC:
1283 		name = "monotonic\n";
1284 		sz = sizeof("monotonic\n");
1285 		break;
1286 	case CLOCK_MONOTONIC_RAW:
1287 		name = "monotonic_raw\n";
1288 		sz = sizeof("monotonic_raw\n");
1289 		break;
1290 	case CLOCK_REALTIME_COARSE:
1291 		name = "realtime_coarse\n";
1292 		sz = sizeof("realtime_coarse\n");
1293 		break;
1294 	case CLOCK_MONOTONIC_COARSE:
1295 		name = "monotonic_coarse\n";
1296 		sz = sizeof("monotonic_coarse\n");
1297 		break;
1298 	case CLOCK_BOOTTIME:
1299 		name = "boottime\n";
1300 		sz = sizeof("boottime\n");
1301 		break;
1302 	case CLOCK_TAI:
1303 		name = "tai\n";
1304 		sz = sizeof("tai\n");
1305 		break;
1306 	default:
1307 		BUG();
1308 	}
1309 
1310 	memcpy(buf, name, sz);
1311 	return sz;
1312 }
1313 
1314 static ssize_t iio_store_timestamp_clock(struct device *dev,
1315 					 struct device_attribute *attr,
1316 					 const char *buf, size_t len)
1317 {
1318 	clockid_t clk;
1319 	int ret;
1320 
1321 	if (sysfs_streq(buf, "realtime"))
1322 		clk = CLOCK_REALTIME;
1323 	else if (sysfs_streq(buf, "monotonic"))
1324 		clk = CLOCK_MONOTONIC;
1325 	else if (sysfs_streq(buf, "monotonic_raw"))
1326 		clk = CLOCK_MONOTONIC_RAW;
1327 	else if (sysfs_streq(buf, "realtime_coarse"))
1328 		clk = CLOCK_REALTIME_COARSE;
1329 	else if (sysfs_streq(buf, "monotonic_coarse"))
1330 		clk = CLOCK_MONOTONIC_COARSE;
1331 	else if (sysfs_streq(buf, "boottime"))
1332 		clk = CLOCK_BOOTTIME;
1333 	else if (sysfs_streq(buf, "tai"))
1334 		clk = CLOCK_TAI;
1335 	else
1336 		return -EINVAL;
1337 
1338 	ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1339 	if (ret)
1340 		return ret;
1341 
1342 	return len;
1343 }
1344 
1345 static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1346 		   iio_show_timestamp_clock, iio_store_timestamp_clock);
1347 
1348 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1349 {
1350 	int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1351 	struct iio_dev_attr *p;
1352 	struct attribute **attr, *clk = NULL;
1353 
1354 	/* First count elements in any existing group */
1355 	if (indio_dev->info->attrs) {
1356 		attr = indio_dev->info->attrs->attrs;
1357 		while (*attr++ != NULL)
1358 			attrcount_orig++;
1359 	}
1360 	attrcount = attrcount_orig;
1361 	/*
1362 	 * New channel registration method - relies on the fact a group does
1363 	 * not need to be initialized if its name is NULL.
1364 	 */
1365 	if (indio_dev->channels)
1366 		for (i = 0; i < indio_dev->num_channels; i++) {
1367 			const struct iio_chan_spec *chan =
1368 				&indio_dev->channels[i];
1369 
1370 			if (chan->type == IIO_TIMESTAMP)
1371 				clk = &dev_attr_current_timestamp_clock.attr;
1372 
1373 			ret = iio_device_add_channel_sysfs(indio_dev, chan);
1374 			if (ret < 0)
1375 				goto error_clear_attrs;
1376 			attrcount += ret;
1377 		}
1378 
1379 	if (indio_dev->event_interface)
1380 		clk = &dev_attr_current_timestamp_clock.attr;
1381 
1382 	if (indio_dev->name)
1383 		attrcount++;
1384 	if (clk)
1385 		attrcount++;
1386 
1387 	indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
1388 						   sizeof(indio_dev->chan_attr_group.attrs[0]),
1389 						   GFP_KERNEL);
1390 	if (indio_dev->chan_attr_group.attrs == NULL) {
1391 		ret = -ENOMEM;
1392 		goto error_clear_attrs;
1393 	}
1394 	/* Copy across original attributes */
1395 	if (indio_dev->info->attrs)
1396 		memcpy(indio_dev->chan_attr_group.attrs,
1397 		       indio_dev->info->attrs->attrs,
1398 		       sizeof(indio_dev->chan_attr_group.attrs[0])
1399 		       *attrcount_orig);
1400 	attrn = attrcount_orig;
1401 	/* Add all elements from the list. */
1402 	list_for_each_entry(p, &indio_dev->channel_attr_list, l)
1403 		indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1404 	if (indio_dev->name)
1405 		indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1406 	if (clk)
1407 		indio_dev->chan_attr_group.attrs[attrn++] = clk;
1408 
1409 	indio_dev->groups[indio_dev->groupcounter++] =
1410 		&indio_dev->chan_attr_group;
1411 
1412 	return 0;
1413 
1414 error_clear_attrs:
1415 	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1416 
1417 	return ret;
1418 }
1419 
1420 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1421 {
1422 
1423 	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1424 	kfree(indio_dev->chan_attr_group.attrs);
1425 	indio_dev->chan_attr_group.attrs = NULL;
1426 }
1427 
1428 static void iio_dev_release(struct device *device)
1429 {
1430 	struct iio_dev *indio_dev = dev_to_iio_dev(device);
1431 	if (indio_dev->modes & (INDIO_BUFFER_TRIGGERED | INDIO_EVENT_TRIGGERED))
1432 		iio_device_unregister_trigger_consumer(indio_dev);
1433 	iio_device_unregister_eventset(indio_dev);
1434 	iio_device_unregister_sysfs(indio_dev);
1435 
1436 	iio_buffer_put(indio_dev->buffer);
1437 
1438 	ida_simple_remove(&iio_ida, indio_dev->id);
1439 	kfree(indio_dev);
1440 }
1441 
1442 struct device_type iio_device_type = {
1443 	.name = "iio_device",
1444 	.release = iio_dev_release,
1445 };
1446 
1447 /**
1448  * iio_device_alloc() - allocate an iio_dev from a driver
1449  * @sizeof_priv:	Space to allocate for private structure.
1450  **/
1451 struct iio_dev *iio_device_alloc(int sizeof_priv)
1452 {
1453 	struct iio_dev *dev;
1454 	size_t alloc_size;
1455 
1456 	alloc_size = sizeof(struct iio_dev);
1457 	if (sizeof_priv) {
1458 		alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1459 		alloc_size += sizeof_priv;
1460 	}
1461 	/* ensure 32-byte alignment of whole construct ? */
1462 	alloc_size += IIO_ALIGN - 1;
1463 
1464 	dev = kzalloc(alloc_size, GFP_KERNEL);
1465 
1466 	if (dev) {
1467 		dev->dev.groups = dev->groups;
1468 		dev->dev.type = &iio_device_type;
1469 		dev->dev.bus = &iio_bus_type;
1470 		device_initialize(&dev->dev);
1471 		dev_set_drvdata(&dev->dev, (void *)dev);
1472 		mutex_init(&dev->mlock);
1473 		mutex_init(&dev->info_exist_lock);
1474 		INIT_LIST_HEAD(&dev->channel_attr_list);
1475 
1476 		dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1477 		if (dev->id < 0) {
1478 			/* cannot use a dev_err as the name isn't available */
1479 			pr_err("failed to get device id\n");
1480 			kfree(dev);
1481 			return NULL;
1482 		}
1483 		dev_set_name(&dev->dev, "iio:device%d", dev->id);
1484 		INIT_LIST_HEAD(&dev->buffer_list);
1485 	}
1486 
1487 	return dev;
1488 }
1489 EXPORT_SYMBOL(iio_device_alloc);
1490 
1491 /**
1492  * iio_device_free() - free an iio_dev from a driver
1493  * @dev:		the iio_dev associated with the device
1494  **/
1495 void iio_device_free(struct iio_dev *dev)
1496 {
1497 	if (dev)
1498 		put_device(&dev->dev);
1499 }
1500 EXPORT_SYMBOL(iio_device_free);
1501 
1502 static void devm_iio_device_release(struct device *dev, void *res)
1503 {
1504 	iio_device_free(*(struct iio_dev **)res);
1505 }
1506 
1507 int devm_iio_device_match(struct device *dev, void *res, void *data)
1508 {
1509 	struct iio_dev **r = res;
1510 	if (!r || !*r) {
1511 		WARN_ON(!r || !*r);
1512 		return 0;
1513 	}
1514 	return *r == data;
1515 }
1516 EXPORT_SYMBOL_GPL(devm_iio_device_match);
1517 
1518 /**
1519  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1520  * @dev:		Device to allocate iio_dev for
1521  * @sizeof_priv:	Space to allocate for private structure.
1522  *
1523  * Managed iio_device_alloc. iio_dev allocated with this function is
1524  * automatically freed on driver detach.
1525  *
1526  * If an iio_dev allocated with this function needs to be freed separately,
1527  * devm_iio_device_free() must be used.
1528  *
1529  * RETURNS:
1530  * Pointer to allocated iio_dev on success, NULL on failure.
1531  */
1532 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1533 {
1534 	struct iio_dev **ptr, *iio_dev;
1535 
1536 	ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1537 			   GFP_KERNEL);
1538 	if (!ptr)
1539 		return NULL;
1540 
1541 	iio_dev = iio_device_alloc(sizeof_priv);
1542 	if (iio_dev) {
1543 		*ptr = iio_dev;
1544 		devres_add(dev, ptr);
1545 	} else {
1546 		devres_free(ptr);
1547 	}
1548 
1549 	return iio_dev;
1550 }
1551 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1552 
1553 /**
1554  * devm_iio_device_free - Resource-managed iio_device_free()
1555  * @dev:		Device this iio_dev belongs to
1556  * @iio_dev:		the iio_dev associated with the device
1557  *
1558  * Free iio_dev allocated with devm_iio_device_alloc().
1559  */
1560 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1561 {
1562 	int rc;
1563 
1564 	rc = devres_release(dev, devm_iio_device_release,
1565 			    devm_iio_device_match, iio_dev);
1566 	WARN_ON(rc);
1567 }
1568 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1569 
1570 /**
1571  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1572  * @inode:	Inode structure for identifying the device in the file system
1573  * @filp:	File structure for iio device used to keep and later access
1574  *		private data
1575  *
1576  * Return: 0 on success or -EBUSY if the device is already opened
1577  **/
1578 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1579 {
1580 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1581 						struct iio_dev, chrdev);
1582 
1583 	if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1584 		return -EBUSY;
1585 
1586 	iio_device_get(indio_dev);
1587 
1588 	filp->private_data = indio_dev;
1589 
1590 	return 0;
1591 }
1592 
1593 /**
1594  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1595  * @inode:	Inode structure pointer for the char device
1596  * @filp:	File structure pointer for the char device
1597  *
1598  * Return: 0 for successful release
1599  */
1600 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1601 {
1602 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1603 						struct iio_dev, chrdev);
1604 	clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1605 	iio_device_put(indio_dev);
1606 
1607 	return 0;
1608 }
1609 
1610 /* Somewhat of a cross file organization violation - ioctls here are actually
1611  * event related */
1612 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1613 {
1614 	struct iio_dev *indio_dev = filp->private_data;
1615 	int __user *ip = (int __user *)arg;
1616 	int fd;
1617 
1618 	if (!indio_dev->info)
1619 		return -ENODEV;
1620 
1621 	if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1622 		fd = iio_event_getfd(indio_dev);
1623 		if (fd < 0)
1624 			return fd;
1625 		if (copy_to_user(ip, &fd, sizeof(fd)))
1626 			return -EFAULT;
1627 		return 0;
1628 	}
1629 	return -EINVAL;
1630 }
1631 
1632 static const struct file_operations iio_buffer_fileops = {
1633 	.read = iio_buffer_read_first_n_outer_addr,
1634 	.release = iio_chrdev_release,
1635 	.open = iio_chrdev_open,
1636 	.poll = iio_buffer_poll_addr,
1637 	.owner = THIS_MODULE,
1638 	.llseek = noop_llseek,
1639 	.unlocked_ioctl = iio_ioctl,
1640 	.compat_ioctl = iio_ioctl,
1641 };
1642 
1643 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1644 {
1645 	int i, j;
1646 	const struct iio_chan_spec *channels = indio_dev->channels;
1647 
1648 	if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1649 		return 0;
1650 
1651 	for (i = 0; i < indio_dev->num_channels - 1; i++) {
1652 		if (channels[i].scan_index < 0)
1653 			continue;
1654 		for (j = i + 1; j < indio_dev->num_channels; j++)
1655 			if (channels[i].scan_index == channels[j].scan_index) {
1656 				dev_err(&indio_dev->dev,
1657 					"Duplicate scan index %d\n",
1658 					channels[i].scan_index);
1659 				return -EINVAL;
1660 			}
1661 	}
1662 
1663 	return 0;
1664 }
1665 
1666 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1667 
1668 /**
1669  * iio_device_register() - register a device with the IIO subsystem
1670  * @indio_dev:		Device structure filled by the device driver
1671  **/
1672 int iio_device_register(struct iio_dev *indio_dev)
1673 {
1674 	int ret;
1675 
1676 	/* If the calling driver did not initialize of_node, do it here */
1677 	if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1678 		indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1679 
1680 	ret = iio_check_unique_scan_index(indio_dev);
1681 	if (ret < 0)
1682 		return ret;
1683 
1684 	/* configure elements for the chrdev */
1685 	indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1686 
1687 	ret = iio_device_register_debugfs(indio_dev);
1688 	if (ret) {
1689 		dev_err(indio_dev->dev.parent,
1690 			"Failed to register debugfs interfaces\n");
1691 		return ret;
1692 	}
1693 
1694 	ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1695 	if (ret) {
1696 		dev_err(indio_dev->dev.parent,
1697 			"Failed to create buffer sysfs interfaces\n");
1698 		goto error_unreg_debugfs;
1699 	}
1700 
1701 	ret = iio_device_register_sysfs(indio_dev);
1702 	if (ret) {
1703 		dev_err(indio_dev->dev.parent,
1704 			"Failed to register sysfs interfaces\n");
1705 		goto error_buffer_free_sysfs;
1706 	}
1707 	ret = iio_device_register_eventset(indio_dev);
1708 	if (ret) {
1709 		dev_err(indio_dev->dev.parent,
1710 			"Failed to register event set\n");
1711 		goto error_free_sysfs;
1712 	}
1713 	if (indio_dev->modes & (INDIO_BUFFER_TRIGGERED | INDIO_EVENT_TRIGGERED))
1714 		iio_device_register_trigger_consumer(indio_dev);
1715 
1716 	if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1717 		indio_dev->setup_ops == NULL)
1718 		indio_dev->setup_ops = &noop_ring_setup_ops;
1719 
1720 	cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1721 	indio_dev->chrdev.owner = indio_dev->info->driver_module;
1722 
1723 	ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev);
1724 	if (ret < 0)
1725 		goto error_unreg_eventset;
1726 
1727 	return 0;
1728 
1729 error_unreg_eventset:
1730 	iio_device_unregister_eventset(indio_dev);
1731 error_free_sysfs:
1732 	iio_device_unregister_sysfs(indio_dev);
1733 error_buffer_free_sysfs:
1734 	iio_buffer_free_sysfs_and_mask(indio_dev);
1735 error_unreg_debugfs:
1736 	iio_device_unregister_debugfs(indio_dev);
1737 	return ret;
1738 }
1739 EXPORT_SYMBOL(iio_device_register);
1740 
1741 /**
1742  * iio_device_unregister() - unregister a device from the IIO subsystem
1743  * @indio_dev:		Device structure representing the device.
1744  **/
1745 void iio_device_unregister(struct iio_dev *indio_dev)
1746 {
1747 	mutex_lock(&indio_dev->info_exist_lock);
1748 
1749 	cdev_device_del(&indio_dev->chrdev, &indio_dev->dev);
1750 
1751 	iio_device_unregister_debugfs(indio_dev);
1752 
1753 	iio_disable_all_buffers(indio_dev);
1754 
1755 	indio_dev->info = NULL;
1756 
1757 	iio_device_wakeup_eventset(indio_dev);
1758 	iio_buffer_wakeup_poll(indio_dev);
1759 
1760 	mutex_unlock(&indio_dev->info_exist_lock);
1761 
1762 	iio_buffer_free_sysfs_and_mask(indio_dev);
1763 }
1764 EXPORT_SYMBOL(iio_device_unregister);
1765 
1766 static void devm_iio_device_unreg(struct device *dev, void *res)
1767 {
1768 	iio_device_unregister(*(struct iio_dev **)res);
1769 }
1770 
1771 /**
1772  * devm_iio_device_register - Resource-managed iio_device_register()
1773  * @dev:	Device to allocate iio_dev for
1774  * @indio_dev:	Device structure filled by the device driver
1775  *
1776  * Managed iio_device_register.  The IIO device registered with this
1777  * function is automatically unregistered on driver detach. This function
1778  * calls iio_device_register() internally. Refer to that function for more
1779  * information.
1780  *
1781  * If an iio_dev registered with this function needs to be unregistered
1782  * separately, devm_iio_device_unregister() must be used.
1783  *
1784  * RETURNS:
1785  * 0 on success, negative error number on failure.
1786  */
1787 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev)
1788 {
1789 	struct iio_dev **ptr;
1790 	int ret;
1791 
1792 	ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1793 	if (!ptr)
1794 		return -ENOMEM;
1795 
1796 	*ptr = indio_dev;
1797 	ret = iio_device_register(indio_dev);
1798 	if (!ret)
1799 		devres_add(dev, ptr);
1800 	else
1801 		devres_free(ptr);
1802 
1803 	return ret;
1804 }
1805 EXPORT_SYMBOL_GPL(devm_iio_device_register);
1806 
1807 /**
1808  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1809  * @dev:	Device this iio_dev belongs to
1810  * @indio_dev:	the iio_dev associated with the device
1811  *
1812  * Unregister iio_dev registered with devm_iio_device_register().
1813  */
1814 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1815 {
1816 	int rc;
1817 
1818 	rc = devres_release(dev, devm_iio_device_unreg,
1819 			    devm_iio_device_match, indio_dev);
1820 	WARN_ON(rc);
1821 }
1822 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1823 
1824 /**
1825  * iio_device_claim_direct_mode - Keep device in direct mode
1826  * @indio_dev:	the iio_dev associated with the device
1827  *
1828  * If the device is in direct mode it is guaranteed to stay
1829  * that way until iio_device_release_direct_mode() is called.
1830  *
1831  * Use with iio_device_release_direct_mode()
1832  *
1833  * Returns: 0 on success, -EBUSY on failure
1834  */
1835 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1836 {
1837 	mutex_lock(&indio_dev->mlock);
1838 
1839 	if (iio_buffer_enabled(indio_dev)) {
1840 		mutex_unlock(&indio_dev->mlock);
1841 		return -EBUSY;
1842 	}
1843 	return 0;
1844 }
1845 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1846 
1847 /**
1848  * iio_device_release_direct_mode - releases claim on direct mode
1849  * @indio_dev:	the iio_dev associated with the device
1850  *
1851  * Release the claim. Device is no longer guaranteed to stay
1852  * in direct mode.
1853  *
1854  * Use with iio_device_claim_direct_mode()
1855  */
1856 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1857 {
1858 	mutex_unlock(&indio_dev->mlock);
1859 }
1860 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1861 
1862 subsys_initcall(iio_init);
1863 module_exit(iio_exit);
1864 
1865 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1866 MODULE_DESCRIPTION("Industrial I/O core");
1867 MODULE_LICENSE("GPL");
1868