1 // SPDX-License-Identifier: GPL-2.0-only
2 /* The industrial I/O core
3  *
4  * Copyright (c) 2008 Jonathan Cameron
5  *
6  * Based on elements of hwmon and input subsystems.
7  */
8 
9 #define pr_fmt(fmt) "iio-core: " fmt
10 
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/idr.h>
14 #include <linux/kdev_t.h>
15 #include <linux/err.h>
16 #include <linux/device.h>
17 #include <linux/fs.h>
18 #include <linux/poll.h>
19 #include <linux/property.h>
20 #include <linux/sched.h>
21 #include <linux/wait.h>
22 #include <linux/cdev.h>
23 #include <linux/slab.h>
24 #include <linux/anon_inodes.h>
25 #include <linux/debugfs.h>
26 #include <linux/mutex.h>
27 #include <linux/iio/iio.h>
28 #include "iio_core.h"
29 #include "iio_core_trigger.h"
30 #include <linux/iio/sysfs.h>
31 #include <linux/iio/events.h>
32 #include <linux/iio/buffer.h>
33 #include <linux/iio/buffer_impl.h>
34 
35 /* IDA to assign each registered device a unique id */
36 static DEFINE_IDA(iio_ida);
37 
38 static dev_t iio_devt;
39 
40 #define IIO_DEV_MAX 256
41 struct bus_type iio_bus_type = {
42 	.name = "iio",
43 };
44 EXPORT_SYMBOL(iio_bus_type);
45 
46 static struct dentry *iio_debugfs_dentry;
47 
48 static const char * const iio_direction[] = {
49 	[0] = "in",
50 	[1] = "out",
51 };
52 
53 static const char * const iio_chan_type_name_spec[] = {
54 	[IIO_VOLTAGE] = "voltage",
55 	[IIO_CURRENT] = "current",
56 	[IIO_POWER] = "power",
57 	[IIO_ACCEL] = "accel",
58 	[IIO_ANGL_VEL] = "anglvel",
59 	[IIO_MAGN] = "magn",
60 	[IIO_LIGHT] = "illuminance",
61 	[IIO_INTENSITY] = "intensity",
62 	[IIO_PROXIMITY] = "proximity",
63 	[IIO_TEMP] = "temp",
64 	[IIO_INCLI] = "incli",
65 	[IIO_ROT] = "rot",
66 	[IIO_ANGL] = "angl",
67 	[IIO_TIMESTAMP] = "timestamp",
68 	[IIO_CAPACITANCE] = "capacitance",
69 	[IIO_ALTVOLTAGE] = "altvoltage",
70 	[IIO_CCT] = "cct",
71 	[IIO_PRESSURE] = "pressure",
72 	[IIO_HUMIDITYRELATIVE] = "humidityrelative",
73 	[IIO_ACTIVITY] = "activity",
74 	[IIO_STEPS] = "steps",
75 	[IIO_ENERGY] = "energy",
76 	[IIO_DISTANCE] = "distance",
77 	[IIO_VELOCITY] = "velocity",
78 	[IIO_CONCENTRATION] = "concentration",
79 	[IIO_RESISTANCE] = "resistance",
80 	[IIO_PH] = "ph",
81 	[IIO_UVINDEX] = "uvindex",
82 	[IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
83 	[IIO_COUNT] = "count",
84 	[IIO_INDEX] = "index",
85 	[IIO_GRAVITY]  = "gravity",
86 	[IIO_POSITIONRELATIVE]  = "positionrelative",
87 	[IIO_PHASE] = "phase",
88 	[IIO_MASSCONCENTRATION] = "massconcentration",
89 };
90 
91 static const char * const iio_modifier_names[] = {
92 	[IIO_MOD_X] = "x",
93 	[IIO_MOD_Y] = "y",
94 	[IIO_MOD_Z] = "z",
95 	[IIO_MOD_X_AND_Y] = "x&y",
96 	[IIO_MOD_X_AND_Z] = "x&z",
97 	[IIO_MOD_Y_AND_Z] = "y&z",
98 	[IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
99 	[IIO_MOD_X_OR_Y] = "x|y",
100 	[IIO_MOD_X_OR_Z] = "x|z",
101 	[IIO_MOD_Y_OR_Z] = "y|z",
102 	[IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
103 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
104 	[IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
105 	[IIO_MOD_LIGHT_BOTH] = "both",
106 	[IIO_MOD_LIGHT_IR] = "ir",
107 	[IIO_MOD_LIGHT_CLEAR] = "clear",
108 	[IIO_MOD_LIGHT_RED] = "red",
109 	[IIO_MOD_LIGHT_GREEN] = "green",
110 	[IIO_MOD_LIGHT_BLUE] = "blue",
111 	[IIO_MOD_LIGHT_UV] = "uv",
112 	[IIO_MOD_LIGHT_DUV] = "duv",
113 	[IIO_MOD_QUATERNION] = "quaternion",
114 	[IIO_MOD_TEMP_AMBIENT] = "ambient",
115 	[IIO_MOD_TEMP_OBJECT] = "object",
116 	[IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
117 	[IIO_MOD_NORTH_TRUE] = "from_north_true",
118 	[IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
119 	[IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
120 	[IIO_MOD_RUNNING] = "running",
121 	[IIO_MOD_JOGGING] = "jogging",
122 	[IIO_MOD_WALKING] = "walking",
123 	[IIO_MOD_STILL] = "still",
124 	[IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
125 	[IIO_MOD_I] = "i",
126 	[IIO_MOD_Q] = "q",
127 	[IIO_MOD_CO2] = "co2",
128 	[IIO_MOD_VOC] = "voc",
129 	[IIO_MOD_PM1] = "pm1",
130 	[IIO_MOD_PM2P5] = "pm2p5",
131 	[IIO_MOD_PM4] = "pm4",
132 	[IIO_MOD_PM10] = "pm10",
133 };
134 
135 /* relies on pairs of these shared then separate */
136 static const char * const iio_chan_info_postfix[] = {
137 	[IIO_CHAN_INFO_RAW] = "raw",
138 	[IIO_CHAN_INFO_PROCESSED] = "input",
139 	[IIO_CHAN_INFO_SCALE] = "scale",
140 	[IIO_CHAN_INFO_OFFSET] = "offset",
141 	[IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
142 	[IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
143 	[IIO_CHAN_INFO_PEAK] = "peak_raw",
144 	[IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
145 	[IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
146 	[IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
147 	[IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
148 	= "filter_low_pass_3db_frequency",
149 	[IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
150 	= "filter_high_pass_3db_frequency",
151 	[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
152 	[IIO_CHAN_INFO_FREQUENCY] = "frequency",
153 	[IIO_CHAN_INFO_PHASE] = "phase",
154 	[IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
155 	[IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
156 	[IIO_CHAN_INFO_INT_TIME] = "integration_time",
157 	[IIO_CHAN_INFO_ENABLE] = "en",
158 	[IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
159 	[IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
160 	[IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
161 	[IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
162 	[IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
163 	[IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
164 	[IIO_CHAN_INFO_THERMOCOUPLE_TYPE] = "thermocouple_type",
165 };
166 
167 /**
168  * iio_find_channel_from_si() - get channel from its scan index
169  * @indio_dev:		device
170  * @si:			scan index to match
171  */
172 const struct iio_chan_spec
173 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
174 {
175 	int i;
176 
177 	for (i = 0; i < indio_dev->num_channels; i++)
178 		if (indio_dev->channels[i].scan_index == si)
179 			return &indio_dev->channels[i];
180 	return NULL;
181 }
182 
183 /* This turns up an awful lot */
184 ssize_t iio_read_const_attr(struct device *dev,
185 			    struct device_attribute *attr,
186 			    char *buf)
187 {
188 	return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
189 }
190 EXPORT_SYMBOL(iio_read_const_attr);
191 
192 static int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
193 {
194 	int ret;
195 	const struct iio_event_interface *ev_int = indio_dev->event_interface;
196 
197 	ret = mutex_lock_interruptible(&indio_dev->mlock);
198 	if (ret)
199 		return ret;
200 	if ((ev_int && iio_event_enabled(ev_int)) ||
201 	    iio_buffer_enabled(indio_dev)) {
202 		mutex_unlock(&indio_dev->mlock);
203 		return -EBUSY;
204 	}
205 	indio_dev->clock_id = clock_id;
206 	mutex_unlock(&indio_dev->mlock);
207 
208 	return 0;
209 }
210 
211 /**
212  * iio_get_time_ns() - utility function to get a time stamp for events etc
213  * @indio_dev: device
214  */
215 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
216 {
217 	struct timespec64 tp;
218 
219 	switch (iio_device_get_clock(indio_dev)) {
220 	case CLOCK_REALTIME:
221 		return ktime_get_real_ns();
222 	case CLOCK_MONOTONIC:
223 		return ktime_get_ns();
224 	case CLOCK_MONOTONIC_RAW:
225 		return ktime_get_raw_ns();
226 	case CLOCK_REALTIME_COARSE:
227 		return ktime_to_ns(ktime_get_coarse_real());
228 	case CLOCK_MONOTONIC_COARSE:
229 		ktime_get_coarse_ts64(&tp);
230 		return timespec64_to_ns(&tp);
231 	case CLOCK_BOOTTIME:
232 		return ktime_get_boottime_ns();
233 	case CLOCK_TAI:
234 		return ktime_get_clocktai_ns();
235 	default:
236 		BUG();
237 	}
238 }
239 EXPORT_SYMBOL(iio_get_time_ns);
240 
241 /**
242  * iio_get_time_res() - utility function to get time stamp clock resolution in
243  *                      nano seconds.
244  * @indio_dev: device
245  */
246 unsigned int iio_get_time_res(const struct iio_dev *indio_dev)
247 {
248 	switch (iio_device_get_clock(indio_dev)) {
249 	case CLOCK_REALTIME:
250 	case CLOCK_MONOTONIC:
251 	case CLOCK_MONOTONIC_RAW:
252 	case CLOCK_BOOTTIME:
253 	case CLOCK_TAI:
254 		return hrtimer_resolution;
255 	case CLOCK_REALTIME_COARSE:
256 	case CLOCK_MONOTONIC_COARSE:
257 		return LOW_RES_NSEC;
258 	default:
259 		BUG();
260 	}
261 }
262 EXPORT_SYMBOL(iio_get_time_res);
263 
264 static int __init iio_init(void)
265 {
266 	int ret;
267 
268 	/* Register sysfs bus */
269 	ret  = bus_register(&iio_bus_type);
270 	if (ret < 0) {
271 		pr_err("could not register bus type\n");
272 		goto error_nothing;
273 	}
274 
275 	ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
276 	if (ret < 0) {
277 		pr_err("failed to allocate char dev region\n");
278 		goto error_unregister_bus_type;
279 	}
280 
281 	iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
282 
283 	return 0;
284 
285 error_unregister_bus_type:
286 	bus_unregister(&iio_bus_type);
287 error_nothing:
288 	return ret;
289 }
290 
291 static void __exit iio_exit(void)
292 {
293 	if (iio_devt)
294 		unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
295 	bus_unregister(&iio_bus_type);
296 	debugfs_remove(iio_debugfs_dentry);
297 }
298 
299 #if defined(CONFIG_DEBUG_FS)
300 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
301 			      size_t count, loff_t *ppos)
302 {
303 	struct iio_dev *indio_dev = file->private_data;
304 	char buf[20];
305 	unsigned val = 0;
306 	ssize_t len;
307 	int ret;
308 
309 	ret = indio_dev->info->debugfs_reg_access(indio_dev,
310 						  indio_dev->cached_reg_addr,
311 						  0, &val);
312 	if (ret) {
313 		dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
314 		return ret;
315 	}
316 
317 	len = snprintf(buf, sizeof(buf), "0x%X\n", val);
318 
319 	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
320 }
321 
322 static ssize_t iio_debugfs_write_reg(struct file *file,
323 		     const char __user *userbuf, size_t count, loff_t *ppos)
324 {
325 	struct iio_dev *indio_dev = file->private_data;
326 	unsigned reg, val;
327 	char buf[80];
328 	int ret;
329 
330 	count = min_t(size_t, count, (sizeof(buf)-1));
331 	if (copy_from_user(buf, userbuf, count))
332 		return -EFAULT;
333 
334 	buf[count] = 0;
335 
336 	ret = sscanf(buf, "%i %i", &reg, &val);
337 
338 	switch (ret) {
339 	case 1:
340 		indio_dev->cached_reg_addr = reg;
341 		break;
342 	case 2:
343 		indio_dev->cached_reg_addr = reg;
344 		ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
345 							  val, NULL);
346 		if (ret) {
347 			dev_err(indio_dev->dev.parent, "%s: write failed\n",
348 				__func__);
349 			return ret;
350 		}
351 		break;
352 	default:
353 		return -EINVAL;
354 	}
355 
356 	return count;
357 }
358 
359 static const struct file_operations iio_debugfs_reg_fops = {
360 	.open = simple_open,
361 	.read = iio_debugfs_read_reg,
362 	.write = iio_debugfs_write_reg,
363 };
364 
365 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
366 {
367 	debugfs_remove_recursive(indio_dev->debugfs_dentry);
368 }
369 
370 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
371 {
372 	if (indio_dev->info->debugfs_reg_access == NULL)
373 		return;
374 
375 	if (!iio_debugfs_dentry)
376 		return;
377 
378 	indio_dev->debugfs_dentry =
379 		debugfs_create_dir(dev_name(&indio_dev->dev),
380 				   iio_debugfs_dentry);
381 
382 	debugfs_create_file("direct_reg_access", 0644,
383 			    indio_dev->debugfs_dentry, indio_dev,
384 			    &iio_debugfs_reg_fops);
385 }
386 #else
387 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
388 {
389 }
390 
391 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
392 {
393 }
394 #endif /* CONFIG_DEBUG_FS */
395 
396 static ssize_t iio_read_channel_ext_info(struct device *dev,
397 				     struct device_attribute *attr,
398 				     char *buf)
399 {
400 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
401 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
402 	const struct iio_chan_spec_ext_info *ext_info;
403 
404 	ext_info = &this_attr->c->ext_info[this_attr->address];
405 
406 	return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
407 }
408 
409 static ssize_t iio_write_channel_ext_info(struct device *dev,
410 				     struct device_attribute *attr,
411 				     const char *buf,
412 					 size_t len)
413 {
414 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
415 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
416 	const struct iio_chan_spec_ext_info *ext_info;
417 
418 	ext_info = &this_attr->c->ext_info[this_attr->address];
419 
420 	return ext_info->write(indio_dev, ext_info->private,
421 			       this_attr->c, buf, len);
422 }
423 
424 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
425 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
426 {
427 	const struct iio_enum *e = (const struct iio_enum *)priv;
428 	unsigned int i;
429 	size_t len = 0;
430 
431 	if (!e->num_items)
432 		return 0;
433 
434 	for (i = 0; i < e->num_items; ++i)
435 		len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
436 
437 	/* replace last space with a newline */
438 	buf[len - 1] = '\n';
439 
440 	return len;
441 }
442 EXPORT_SYMBOL_GPL(iio_enum_available_read);
443 
444 ssize_t iio_enum_read(struct iio_dev *indio_dev,
445 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
446 {
447 	const struct iio_enum *e = (const struct iio_enum *)priv;
448 	int i;
449 
450 	if (!e->get)
451 		return -EINVAL;
452 
453 	i = e->get(indio_dev, chan);
454 	if (i < 0)
455 		return i;
456 	else if (i >= e->num_items)
457 		return -EINVAL;
458 
459 	return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
460 }
461 EXPORT_SYMBOL_GPL(iio_enum_read);
462 
463 ssize_t iio_enum_write(struct iio_dev *indio_dev,
464 	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
465 	size_t len)
466 {
467 	const struct iio_enum *e = (const struct iio_enum *)priv;
468 	int ret;
469 
470 	if (!e->set)
471 		return -EINVAL;
472 
473 	ret = __sysfs_match_string(e->items, e->num_items, buf);
474 	if (ret < 0)
475 		return ret;
476 
477 	ret = e->set(indio_dev, chan, ret);
478 	return ret ? ret : len;
479 }
480 EXPORT_SYMBOL_GPL(iio_enum_write);
481 
482 static const struct iio_mount_matrix iio_mount_idmatrix = {
483 	.rotation = {
484 		"1", "0", "0",
485 		"0", "1", "0",
486 		"0", "0", "1"
487 	}
488 };
489 
490 static int iio_setup_mount_idmatrix(const struct device *dev,
491 				    struct iio_mount_matrix *matrix)
492 {
493 	*matrix = iio_mount_idmatrix;
494 	dev_info(dev, "mounting matrix not found: using identity...\n");
495 	return 0;
496 }
497 
498 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
499 			      const struct iio_chan_spec *chan, char *buf)
500 {
501 	const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
502 					      priv)(indio_dev, chan);
503 
504 	if (IS_ERR(mtx))
505 		return PTR_ERR(mtx);
506 
507 	if (!mtx)
508 		mtx = &iio_mount_idmatrix;
509 
510 	return snprintf(buf, PAGE_SIZE, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
511 			mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
512 			mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
513 			mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
514 }
515 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
516 
517 /**
518  * iio_read_mount_matrix() - retrieve iio device mounting matrix from
519  *                           device "mount-matrix" property
520  * @dev:	device the mounting matrix property is assigned to
521  * @propname:	device specific mounting matrix property name
522  * @matrix:	where to store retrieved matrix
523  *
524  * If device is assigned no mounting matrix property, a default 3x3 identity
525  * matrix will be filled in.
526  *
527  * Return: 0 if success, or a negative error code on failure.
528  */
529 int iio_read_mount_matrix(struct device *dev, const char *propname,
530 			  struct iio_mount_matrix *matrix)
531 {
532 	size_t len = ARRAY_SIZE(iio_mount_idmatrix.rotation);
533 	int err;
534 
535 	err = device_property_read_string_array(dev, propname,
536 						matrix->rotation, len);
537 	if (err == len)
538 		return 0;
539 
540 	if (err >= 0)
541 		/* Invalid number of matrix entries. */
542 		return -EINVAL;
543 
544 	if (err != -EINVAL)
545 		/* Invalid matrix declaration format. */
546 		return err;
547 
548 	/* Matrix was not declared at all: fallback to identity. */
549 	return iio_setup_mount_idmatrix(dev, matrix);
550 }
551 EXPORT_SYMBOL(iio_read_mount_matrix);
552 
553 static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
554 				  int size, const int *vals)
555 {
556 	unsigned long long tmp;
557 	int tmp0, tmp1;
558 	bool scale_db = false;
559 
560 	switch (type) {
561 	case IIO_VAL_INT:
562 		return snprintf(buf, len, "%d", vals[0]);
563 	case IIO_VAL_INT_PLUS_MICRO_DB:
564 		scale_db = true;
565 		/* fall through */
566 	case IIO_VAL_INT_PLUS_MICRO:
567 		if (vals[1] < 0)
568 			return snprintf(buf, len, "-%d.%06u%s", abs(vals[0]),
569 					-vals[1], scale_db ? " dB" : "");
570 		else
571 			return snprintf(buf, len, "%d.%06u%s", vals[0], vals[1],
572 					scale_db ? " dB" : "");
573 	case IIO_VAL_INT_PLUS_NANO:
574 		if (vals[1] < 0)
575 			return snprintf(buf, len, "-%d.%09u", abs(vals[0]),
576 					-vals[1]);
577 		else
578 			return snprintf(buf, len, "%d.%09u", vals[0], vals[1]);
579 	case IIO_VAL_FRACTIONAL:
580 		tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
581 		tmp1 = vals[1];
582 		tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1);
583 		return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
584 	case IIO_VAL_FRACTIONAL_LOG2:
585 		tmp = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
586 		tmp0 = (int)div_s64_rem(tmp, 1000000000LL, &tmp1);
587 		return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
588 	case IIO_VAL_INT_MULTIPLE:
589 	{
590 		int i;
591 		int l = 0;
592 
593 		for (i = 0; i < size; ++i) {
594 			l += snprintf(&buf[l], len - l, "%d ", vals[i]);
595 			if (l >= len)
596 				break;
597 		}
598 		return l;
599 	}
600 	case IIO_VAL_CHAR:
601 		return snprintf(buf, len, "%c", (char)vals[0]);
602 	default:
603 		return 0;
604 	}
605 }
606 
607 /**
608  * iio_format_value() - Formats a IIO value into its string representation
609  * @buf:	The buffer to which the formatted value gets written
610  *		which is assumed to be big enough (i.e. PAGE_SIZE).
611  * @type:	One of the IIO_VAL_* constants. This decides how the val
612  *		and val2 parameters are formatted.
613  * @size:	Number of IIO value entries contained in vals
614  * @vals:	Pointer to the values, exact meaning depends on the
615  *		type parameter.
616  *
617  * Return: 0 by default, a negative number on failure or the
618  *	   total number of characters written for a type that belongs
619  *	   to the IIO_VAL_* constant.
620  */
621 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
622 {
623 	ssize_t len;
624 
625 	len = __iio_format_value(buf, PAGE_SIZE, type, size, vals);
626 	if (len >= PAGE_SIZE - 1)
627 		return -EFBIG;
628 
629 	return len + sprintf(buf + len, "\n");
630 }
631 EXPORT_SYMBOL_GPL(iio_format_value);
632 
633 static ssize_t iio_read_channel_info(struct device *dev,
634 				     struct device_attribute *attr,
635 				     char *buf)
636 {
637 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
638 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
639 	int vals[INDIO_MAX_RAW_ELEMENTS];
640 	int ret;
641 	int val_len = 2;
642 
643 	if (indio_dev->info->read_raw_multi)
644 		ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
645 							INDIO_MAX_RAW_ELEMENTS,
646 							vals, &val_len,
647 							this_attr->address);
648 	else
649 		ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
650 				    &vals[0], &vals[1], this_attr->address);
651 
652 	if (ret < 0)
653 		return ret;
654 
655 	return iio_format_value(buf, ret, val_len, vals);
656 }
657 
658 static ssize_t iio_format_avail_list(char *buf, const int *vals,
659 				     int type, int length)
660 {
661 	int i;
662 	ssize_t len = 0;
663 
664 	switch (type) {
665 	case IIO_VAL_INT:
666 		for (i = 0; i < length; i++) {
667 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
668 						  type, 1, &vals[i]);
669 			if (len >= PAGE_SIZE)
670 				return -EFBIG;
671 			if (i < length - 1)
672 				len += snprintf(buf + len, PAGE_SIZE - len,
673 						" ");
674 			else
675 				len += snprintf(buf + len, PAGE_SIZE - len,
676 						"\n");
677 			if (len >= PAGE_SIZE)
678 				return -EFBIG;
679 		}
680 		break;
681 	default:
682 		for (i = 0; i < length / 2; i++) {
683 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
684 						  type, 2, &vals[i * 2]);
685 			if (len >= PAGE_SIZE)
686 				return -EFBIG;
687 			if (i < length / 2 - 1)
688 				len += snprintf(buf + len, PAGE_SIZE - len,
689 						" ");
690 			else
691 				len += snprintf(buf + len, PAGE_SIZE - len,
692 						"\n");
693 			if (len >= PAGE_SIZE)
694 				return -EFBIG;
695 		}
696 	}
697 
698 	return len;
699 }
700 
701 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
702 {
703 	int i;
704 	ssize_t len;
705 
706 	len = snprintf(buf, PAGE_SIZE, "[");
707 	switch (type) {
708 	case IIO_VAL_INT:
709 		for (i = 0; i < 3; i++) {
710 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
711 						  type, 1, &vals[i]);
712 			if (len >= PAGE_SIZE)
713 				return -EFBIG;
714 			if (i < 2)
715 				len += snprintf(buf + len, PAGE_SIZE - len,
716 						" ");
717 			else
718 				len += snprintf(buf + len, PAGE_SIZE - len,
719 						"]\n");
720 			if (len >= PAGE_SIZE)
721 				return -EFBIG;
722 		}
723 		break;
724 	default:
725 		for (i = 0; i < 3; i++) {
726 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
727 						  type, 2, &vals[i * 2]);
728 			if (len >= PAGE_SIZE)
729 				return -EFBIG;
730 			if (i < 2)
731 				len += snprintf(buf + len, PAGE_SIZE - len,
732 						" ");
733 			else
734 				len += snprintf(buf + len, PAGE_SIZE - len,
735 						"]\n");
736 			if (len >= PAGE_SIZE)
737 				return -EFBIG;
738 		}
739 	}
740 
741 	return len;
742 }
743 
744 static ssize_t iio_read_channel_info_avail(struct device *dev,
745 					   struct device_attribute *attr,
746 					   char *buf)
747 {
748 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
749 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
750 	const int *vals;
751 	int ret;
752 	int length;
753 	int type;
754 
755 	ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
756 					  &vals, &type, &length,
757 					  this_attr->address);
758 
759 	if (ret < 0)
760 		return ret;
761 	switch (ret) {
762 	case IIO_AVAIL_LIST:
763 		return iio_format_avail_list(buf, vals, type, length);
764 	case IIO_AVAIL_RANGE:
765 		return iio_format_avail_range(buf, vals, type);
766 	default:
767 		return -EINVAL;
768 	}
769 }
770 
771 /**
772  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
773  * @str: The string to parse
774  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
775  * @integer: The integer part of the number
776  * @fract: The fractional part of the number
777  *
778  * Returns 0 on success, or a negative error code if the string could not be
779  * parsed.
780  */
781 int iio_str_to_fixpoint(const char *str, int fract_mult,
782 	int *integer, int *fract)
783 {
784 	int i = 0, f = 0;
785 	bool integer_part = true, negative = false;
786 
787 	if (fract_mult == 0) {
788 		*fract = 0;
789 
790 		return kstrtoint(str, 0, integer);
791 	}
792 
793 	if (str[0] == '-') {
794 		negative = true;
795 		str++;
796 	} else if (str[0] == '+') {
797 		str++;
798 	}
799 
800 	while (*str) {
801 		if ('0' <= *str && *str <= '9') {
802 			if (integer_part) {
803 				i = i * 10 + *str - '0';
804 			} else {
805 				f += fract_mult * (*str - '0');
806 				fract_mult /= 10;
807 			}
808 		} else if (*str == '\n') {
809 			if (*(str + 1) == '\0')
810 				break;
811 			else
812 				return -EINVAL;
813 		} else if (*str == '.' && integer_part) {
814 			integer_part = false;
815 		} else {
816 			return -EINVAL;
817 		}
818 		str++;
819 	}
820 
821 	if (negative) {
822 		if (i)
823 			i = -i;
824 		else
825 			f = -f;
826 	}
827 
828 	*integer = i;
829 	*fract = f;
830 
831 	return 0;
832 }
833 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
834 
835 static ssize_t iio_write_channel_info(struct device *dev,
836 				      struct device_attribute *attr,
837 				      const char *buf,
838 				      size_t len)
839 {
840 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
841 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
842 	int ret, fract_mult = 100000;
843 	int integer, fract = 0;
844 	bool is_char = false;
845 
846 	/* Assumes decimal - precision based on number of digits */
847 	if (!indio_dev->info->write_raw)
848 		return -EINVAL;
849 
850 	if (indio_dev->info->write_raw_get_fmt)
851 		switch (indio_dev->info->write_raw_get_fmt(indio_dev,
852 			this_attr->c, this_attr->address)) {
853 		case IIO_VAL_INT:
854 			fract_mult = 0;
855 			break;
856 		case IIO_VAL_INT_PLUS_MICRO:
857 			fract_mult = 100000;
858 			break;
859 		case IIO_VAL_INT_PLUS_NANO:
860 			fract_mult = 100000000;
861 			break;
862 		case IIO_VAL_CHAR:
863 			is_char = true;
864 			break;
865 		default:
866 			return -EINVAL;
867 		}
868 
869 	if (is_char) {
870 		char ch;
871 
872 		if (sscanf(buf, "%c", &ch) != 1)
873 			return -EINVAL;
874 		integer = ch;
875 	} else {
876 		ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
877 		if (ret)
878 			return ret;
879 	}
880 
881 	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
882 					 integer, fract, this_attr->address);
883 	if (ret)
884 		return ret;
885 
886 	return len;
887 }
888 
889 static
890 int __iio_device_attr_init(struct device_attribute *dev_attr,
891 			   const char *postfix,
892 			   struct iio_chan_spec const *chan,
893 			   ssize_t (*readfunc)(struct device *dev,
894 					       struct device_attribute *attr,
895 					       char *buf),
896 			   ssize_t (*writefunc)(struct device *dev,
897 						struct device_attribute *attr,
898 						const char *buf,
899 						size_t len),
900 			   enum iio_shared_by shared_by)
901 {
902 	int ret = 0;
903 	char *name = NULL;
904 	char *full_postfix;
905 	sysfs_attr_init(&dev_attr->attr);
906 
907 	/* Build up postfix of <extend_name>_<modifier>_postfix */
908 	if (chan->modified && (shared_by == IIO_SEPARATE)) {
909 		if (chan->extend_name)
910 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
911 						 iio_modifier_names[chan
912 								    ->channel2],
913 						 chan->extend_name,
914 						 postfix);
915 		else
916 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
917 						 iio_modifier_names[chan
918 								    ->channel2],
919 						 postfix);
920 	} else {
921 		if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
922 			full_postfix = kstrdup(postfix, GFP_KERNEL);
923 		else
924 			full_postfix = kasprintf(GFP_KERNEL,
925 						 "%s_%s",
926 						 chan->extend_name,
927 						 postfix);
928 	}
929 	if (full_postfix == NULL)
930 		return -ENOMEM;
931 
932 	if (chan->differential) { /* Differential can not have modifier */
933 		switch (shared_by) {
934 		case IIO_SHARED_BY_ALL:
935 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
936 			break;
937 		case IIO_SHARED_BY_DIR:
938 			name = kasprintf(GFP_KERNEL, "%s_%s",
939 						iio_direction[chan->output],
940 						full_postfix);
941 			break;
942 		case IIO_SHARED_BY_TYPE:
943 			name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
944 					    iio_direction[chan->output],
945 					    iio_chan_type_name_spec[chan->type],
946 					    iio_chan_type_name_spec[chan->type],
947 					    full_postfix);
948 			break;
949 		case IIO_SEPARATE:
950 			if (!chan->indexed) {
951 				WARN(1, "Differential channels must be indexed\n");
952 				ret = -EINVAL;
953 				goto error_free_full_postfix;
954 			}
955 			name = kasprintf(GFP_KERNEL,
956 					    "%s_%s%d-%s%d_%s",
957 					    iio_direction[chan->output],
958 					    iio_chan_type_name_spec[chan->type],
959 					    chan->channel,
960 					    iio_chan_type_name_spec[chan->type],
961 					    chan->channel2,
962 					    full_postfix);
963 			break;
964 		}
965 	} else { /* Single ended */
966 		switch (shared_by) {
967 		case IIO_SHARED_BY_ALL:
968 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
969 			break;
970 		case IIO_SHARED_BY_DIR:
971 			name = kasprintf(GFP_KERNEL, "%s_%s",
972 						iio_direction[chan->output],
973 						full_postfix);
974 			break;
975 		case IIO_SHARED_BY_TYPE:
976 			name = kasprintf(GFP_KERNEL, "%s_%s_%s",
977 					    iio_direction[chan->output],
978 					    iio_chan_type_name_spec[chan->type],
979 					    full_postfix);
980 			break;
981 
982 		case IIO_SEPARATE:
983 			if (chan->indexed)
984 				name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
985 						    iio_direction[chan->output],
986 						    iio_chan_type_name_spec[chan->type],
987 						    chan->channel,
988 						    full_postfix);
989 			else
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 	}
997 	if (name == NULL) {
998 		ret = -ENOMEM;
999 		goto error_free_full_postfix;
1000 	}
1001 	dev_attr->attr.name = name;
1002 
1003 	if (readfunc) {
1004 		dev_attr->attr.mode |= S_IRUGO;
1005 		dev_attr->show = readfunc;
1006 	}
1007 
1008 	if (writefunc) {
1009 		dev_attr->attr.mode |= S_IWUSR;
1010 		dev_attr->store = writefunc;
1011 	}
1012 
1013 error_free_full_postfix:
1014 	kfree(full_postfix);
1015 
1016 	return ret;
1017 }
1018 
1019 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1020 {
1021 	kfree(dev_attr->attr.name);
1022 }
1023 
1024 int __iio_add_chan_devattr(const char *postfix,
1025 			   struct iio_chan_spec const *chan,
1026 			   ssize_t (*readfunc)(struct device *dev,
1027 					       struct device_attribute *attr,
1028 					       char *buf),
1029 			   ssize_t (*writefunc)(struct device *dev,
1030 						struct device_attribute *attr,
1031 						const char *buf,
1032 						size_t len),
1033 			   u64 mask,
1034 			   enum iio_shared_by shared_by,
1035 			   struct device *dev,
1036 			   struct list_head *attr_list)
1037 {
1038 	int ret;
1039 	struct iio_dev_attr *iio_attr, *t;
1040 
1041 	iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1042 	if (iio_attr == NULL)
1043 		return -ENOMEM;
1044 	ret = __iio_device_attr_init(&iio_attr->dev_attr,
1045 				     postfix, chan,
1046 				     readfunc, writefunc, shared_by);
1047 	if (ret)
1048 		goto error_iio_dev_attr_free;
1049 	iio_attr->c = chan;
1050 	iio_attr->address = mask;
1051 	list_for_each_entry(t, attr_list, l)
1052 		if (strcmp(t->dev_attr.attr.name,
1053 			   iio_attr->dev_attr.attr.name) == 0) {
1054 			if (shared_by == IIO_SEPARATE)
1055 				dev_err(dev, "tried to double register : %s\n",
1056 					t->dev_attr.attr.name);
1057 			ret = -EBUSY;
1058 			goto error_device_attr_deinit;
1059 		}
1060 	list_add(&iio_attr->l, attr_list);
1061 
1062 	return 0;
1063 
1064 error_device_attr_deinit:
1065 	__iio_device_attr_deinit(&iio_attr->dev_attr);
1066 error_iio_dev_attr_free:
1067 	kfree(iio_attr);
1068 	return ret;
1069 }
1070 
1071 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1072 					 struct iio_chan_spec const *chan,
1073 					 enum iio_shared_by shared_by,
1074 					 const long *infomask)
1075 {
1076 	int i, ret, attrcount = 0;
1077 
1078 	for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1079 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1080 			return -EINVAL;
1081 		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1082 					     chan,
1083 					     &iio_read_channel_info,
1084 					     &iio_write_channel_info,
1085 					     i,
1086 					     shared_by,
1087 					     &indio_dev->dev,
1088 					     &indio_dev->channel_attr_list);
1089 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1090 			continue;
1091 		else if (ret < 0)
1092 			return ret;
1093 		attrcount++;
1094 	}
1095 
1096 	return attrcount;
1097 }
1098 
1099 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1100 					       struct iio_chan_spec const *chan,
1101 					       enum iio_shared_by shared_by,
1102 					       const long *infomask)
1103 {
1104 	int i, ret, attrcount = 0;
1105 	char *avail_postfix;
1106 
1107 	for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1108 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1109 			return -EINVAL;
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_dev_label(struct device *dev,
1257 				 struct device_attribute *attr,
1258 				 char *buf)
1259 {
1260 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1261 	return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->label);
1262 }
1263 
1264 static DEVICE_ATTR(label, S_IRUGO, iio_show_dev_label, NULL);
1265 
1266 static ssize_t iio_show_timestamp_clock(struct device *dev,
1267 					struct device_attribute *attr,
1268 					char *buf)
1269 {
1270 	const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1271 	const clockid_t clk = iio_device_get_clock(indio_dev);
1272 	const char *name;
1273 	ssize_t sz;
1274 
1275 	switch (clk) {
1276 	case CLOCK_REALTIME:
1277 		name = "realtime\n";
1278 		sz = sizeof("realtime\n");
1279 		break;
1280 	case CLOCK_MONOTONIC:
1281 		name = "monotonic\n";
1282 		sz = sizeof("monotonic\n");
1283 		break;
1284 	case CLOCK_MONOTONIC_RAW:
1285 		name = "monotonic_raw\n";
1286 		sz = sizeof("monotonic_raw\n");
1287 		break;
1288 	case CLOCK_REALTIME_COARSE:
1289 		name = "realtime_coarse\n";
1290 		sz = sizeof("realtime_coarse\n");
1291 		break;
1292 	case CLOCK_MONOTONIC_COARSE:
1293 		name = "monotonic_coarse\n";
1294 		sz = sizeof("monotonic_coarse\n");
1295 		break;
1296 	case CLOCK_BOOTTIME:
1297 		name = "boottime\n";
1298 		sz = sizeof("boottime\n");
1299 		break;
1300 	case CLOCK_TAI:
1301 		name = "tai\n";
1302 		sz = sizeof("tai\n");
1303 		break;
1304 	default:
1305 		BUG();
1306 	}
1307 
1308 	memcpy(buf, name, sz);
1309 	return sz;
1310 }
1311 
1312 static ssize_t iio_store_timestamp_clock(struct device *dev,
1313 					 struct device_attribute *attr,
1314 					 const char *buf, size_t len)
1315 {
1316 	clockid_t clk;
1317 	int ret;
1318 
1319 	if (sysfs_streq(buf, "realtime"))
1320 		clk = CLOCK_REALTIME;
1321 	else if (sysfs_streq(buf, "monotonic"))
1322 		clk = CLOCK_MONOTONIC;
1323 	else if (sysfs_streq(buf, "monotonic_raw"))
1324 		clk = CLOCK_MONOTONIC_RAW;
1325 	else if (sysfs_streq(buf, "realtime_coarse"))
1326 		clk = CLOCK_REALTIME_COARSE;
1327 	else if (sysfs_streq(buf, "monotonic_coarse"))
1328 		clk = CLOCK_MONOTONIC_COARSE;
1329 	else if (sysfs_streq(buf, "boottime"))
1330 		clk = CLOCK_BOOTTIME;
1331 	else if (sysfs_streq(buf, "tai"))
1332 		clk = CLOCK_TAI;
1333 	else
1334 		return -EINVAL;
1335 
1336 	ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1337 	if (ret)
1338 		return ret;
1339 
1340 	return len;
1341 }
1342 
1343 static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1344 		   iio_show_timestamp_clock, iio_store_timestamp_clock);
1345 
1346 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1347 {
1348 	int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1349 	struct iio_dev_attr *p;
1350 	struct attribute **attr, *clk = NULL;
1351 
1352 	/* First count elements in any existing group */
1353 	if (indio_dev->info->attrs) {
1354 		attr = indio_dev->info->attrs->attrs;
1355 		while (*attr++ != NULL)
1356 			attrcount_orig++;
1357 	}
1358 	attrcount = attrcount_orig;
1359 	/*
1360 	 * New channel registration method - relies on the fact a group does
1361 	 * not need to be initialized if its name is NULL.
1362 	 */
1363 	if (indio_dev->channels)
1364 		for (i = 0; i < indio_dev->num_channels; i++) {
1365 			const struct iio_chan_spec *chan =
1366 				&indio_dev->channels[i];
1367 
1368 			if (chan->type == IIO_TIMESTAMP)
1369 				clk = &dev_attr_current_timestamp_clock.attr;
1370 
1371 			ret = iio_device_add_channel_sysfs(indio_dev, chan);
1372 			if (ret < 0)
1373 				goto error_clear_attrs;
1374 			attrcount += ret;
1375 		}
1376 
1377 	if (indio_dev->event_interface)
1378 		clk = &dev_attr_current_timestamp_clock.attr;
1379 
1380 	if (indio_dev->name)
1381 		attrcount++;
1382 	if (indio_dev->label)
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 (indio_dev->label)
1407 		indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_label.attr;
1408 	if (clk)
1409 		indio_dev->chan_attr_group.attrs[attrn++] = clk;
1410 
1411 	indio_dev->groups[indio_dev->groupcounter++] =
1412 		&indio_dev->chan_attr_group;
1413 
1414 	return 0;
1415 
1416 error_clear_attrs:
1417 	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1418 
1419 	return ret;
1420 }
1421 
1422 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1423 {
1424 
1425 	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1426 	kfree(indio_dev->chan_attr_group.attrs);
1427 	indio_dev->chan_attr_group.attrs = NULL;
1428 }
1429 
1430 static void iio_dev_release(struct device *device)
1431 {
1432 	struct iio_dev *indio_dev = dev_to_iio_dev(device);
1433 	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1434 		iio_device_unregister_trigger_consumer(indio_dev);
1435 	iio_device_unregister_eventset(indio_dev);
1436 	iio_device_unregister_sysfs(indio_dev);
1437 
1438 	iio_buffer_put(indio_dev->buffer);
1439 
1440 	ida_simple_remove(&iio_ida, indio_dev->id);
1441 	kfree(indio_dev);
1442 }
1443 
1444 struct device_type iio_device_type = {
1445 	.name = "iio_device",
1446 	.release = iio_dev_release,
1447 };
1448 
1449 /**
1450  * iio_device_alloc() - allocate an iio_dev from a driver
1451  * @sizeof_priv:	Space to allocate for private structure.
1452  **/
1453 struct iio_dev *iio_device_alloc(int sizeof_priv)
1454 {
1455 	struct iio_dev *dev;
1456 	size_t alloc_size;
1457 
1458 	alloc_size = sizeof(struct iio_dev);
1459 	if (sizeof_priv) {
1460 		alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1461 		alloc_size += sizeof_priv;
1462 	}
1463 	/* ensure 32-byte alignment of whole construct ? */
1464 	alloc_size += IIO_ALIGN - 1;
1465 
1466 	dev = kzalloc(alloc_size, GFP_KERNEL);
1467 
1468 	if (dev) {
1469 		dev->dev.groups = dev->groups;
1470 		dev->dev.type = &iio_device_type;
1471 		dev->dev.bus = &iio_bus_type;
1472 		device_initialize(&dev->dev);
1473 		dev_set_drvdata(&dev->dev, (void *)dev);
1474 		mutex_init(&dev->mlock);
1475 		mutex_init(&dev->info_exist_lock);
1476 		INIT_LIST_HEAD(&dev->channel_attr_list);
1477 
1478 		dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1479 		if (dev->id < 0) {
1480 			/* cannot use a dev_err as the name isn't available */
1481 			pr_err("failed to get device id\n");
1482 			kfree(dev);
1483 			return NULL;
1484 		}
1485 		dev_set_name(&dev->dev, "iio:device%d", dev->id);
1486 		INIT_LIST_HEAD(&dev->buffer_list);
1487 	}
1488 
1489 	return dev;
1490 }
1491 EXPORT_SYMBOL(iio_device_alloc);
1492 
1493 /**
1494  * iio_device_free() - free an iio_dev from a driver
1495  * @dev:		the iio_dev associated with the device
1496  **/
1497 void iio_device_free(struct iio_dev *dev)
1498 {
1499 	if (dev)
1500 		put_device(&dev->dev);
1501 }
1502 EXPORT_SYMBOL(iio_device_free);
1503 
1504 static void devm_iio_device_release(struct device *dev, void *res)
1505 {
1506 	iio_device_free(*(struct iio_dev **)res);
1507 }
1508 
1509 int devm_iio_device_match(struct device *dev, void *res, void *data)
1510 {
1511 	struct iio_dev **r = res;
1512 	if (!r || !*r) {
1513 		WARN_ON(!r || !*r);
1514 		return 0;
1515 	}
1516 	return *r == data;
1517 }
1518 EXPORT_SYMBOL_GPL(devm_iio_device_match);
1519 
1520 /**
1521  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1522  * @dev:		Device to allocate iio_dev for
1523  * @sizeof_priv:	Space to allocate for private structure.
1524  *
1525  * Managed iio_device_alloc. iio_dev allocated with this function is
1526  * automatically freed on driver detach.
1527  *
1528  * If an iio_dev allocated with this function needs to be freed separately,
1529  * devm_iio_device_free() must be used.
1530  *
1531  * RETURNS:
1532  * Pointer to allocated iio_dev on success, NULL on failure.
1533  */
1534 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1535 {
1536 	struct iio_dev **ptr, *iio_dev;
1537 
1538 	ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1539 			   GFP_KERNEL);
1540 	if (!ptr)
1541 		return NULL;
1542 
1543 	iio_dev = iio_device_alloc(sizeof_priv);
1544 	if (iio_dev) {
1545 		*ptr = iio_dev;
1546 		devres_add(dev, ptr);
1547 	} else {
1548 		devres_free(ptr);
1549 	}
1550 
1551 	return iio_dev;
1552 }
1553 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1554 
1555 /**
1556  * devm_iio_device_free - Resource-managed iio_device_free()
1557  * @dev:		Device this iio_dev belongs to
1558  * @iio_dev:		the iio_dev associated with the device
1559  *
1560  * Free iio_dev allocated with devm_iio_device_alloc().
1561  */
1562 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1563 {
1564 	int rc;
1565 
1566 	rc = devres_release(dev, devm_iio_device_release,
1567 			    devm_iio_device_match, iio_dev);
1568 	WARN_ON(rc);
1569 }
1570 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1571 
1572 /**
1573  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1574  * @inode:	Inode structure for identifying the device in the file system
1575  * @filp:	File structure for iio device used to keep and later access
1576  *		private data
1577  *
1578  * Return: 0 on success or -EBUSY if the device is already opened
1579  **/
1580 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1581 {
1582 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1583 						struct iio_dev, chrdev);
1584 
1585 	if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1586 		return -EBUSY;
1587 
1588 	iio_device_get(indio_dev);
1589 
1590 	filp->private_data = indio_dev;
1591 
1592 	return 0;
1593 }
1594 
1595 /**
1596  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1597  * @inode:	Inode structure pointer for the char device
1598  * @filp:	File structure pointer for the char device
1599  *
1600  * Return: 0 for successful release
1601  */
1602 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1603 {
1604 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1605 						struct iio_dev, chrdev);
1606 	clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1607 	iio_device_put(indio_dev);
1608 
1609 	return 0;
1610 }
1611 
1612 /* Somewhat of a cross file organization violation - ioctls here are actually
1613  * event related */
1614 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1615 {
1616 	struct iio_dev *indio_dev = filp->private_data;
1617 	int __user *ip = (int __user *)arg;
1618 	int fd;
1619 
1620 	if (!indio_dev->info)
1621 		return -ENODEV;
1622 
1623 	if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1624 		fd = iio_event_getfd(indio_dev);
1625 		if (fd < 0)
1626 			return fd;
1627 		if (copy_to_user(ip, &fd, sizeof(fd)))
1628 			return -EFAULT;
1629 		return 0;
1630 	}
1631 	return -EINVAL;
1632 }
1633 
1634 static const struct file_operations iio_buffer_fileops = {
1635 	.read = iio_buffer_read_outer_addr,
1636 	.release = iio_chrdev_release,
1637 	.open = iio_chrdev_open,
1638 	.poll = iio_buffer_poll_addr,
1639 	.owner = THIS_MODULE,
1640 	.llseek = noop_llseek,
1641 	.unlocked_ioctl = iio_ioctl,
1642 	.compat_ioctl = compat_ptr_ioctl,
1643 };
1644 
1645 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1646 {
1647 	int i, j;
1648 	const struct iio_chan_spec *channels = indio_dev->channels;
1649 
1650 	if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1651 		return 0;
1652 
1653 	for (i = 0; i < indio_dev->num_channels - 1; i++) {
1654 		if (channels[i].scan_index < 0)
1655 			continue;
1656 		for (j = i + 1; j < indio_dev->num_channels; j++)
1657 			if (channels[i].scan_index == channels[j].scan_index) {
1658 				dev_err(&indio_dev->dev,
1659 					"Duplicate scan index %d\n",
1660 					channels[i].scan_index);
1661 				return -EINVAL;
1662 			}
1663 	}
1664 
1665 	return 0;
1666 }
1667 
1668 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1669 
1670 int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1671 {
1672 	int ret;
1673 
1674 	indio_dev->driver_module = this_mod;
1675 	/* If the calling driver did not initialize of_node, do it here */
1676 	if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1677 		indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1678 
1679 	indio_dev->label = of_get_property(indio_dev->dev.of_node, "label",
1680 					   NULL);
1681 
1682 	ret = iio_check_unique_scan_index(indio_dev);
1683 	if (ret < 0)
1684 		return ret;
1685 
1686 	if (!indio_dev->info)
1687 		return -EINVAL;
1688 
1689 	/* configure elements for the chrdev */
1690 	indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1691 
1692 	iio_device_register_debugfs(indio_dev);
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_ALL_TRIGGERED_MODES)
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 
1722 	indio_dev->chrdev.owner = this_mod;
1723 
1724 	ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev);
1725 	if (ret < 0)
1726 		goto error_unreg_eventset;
1727 
1728 	return 0;
1729 
1730 error_unreg_eventset:
1731 	iio_device_unregister_eventset(indio_dev);
1732 error_free_sysfs:
1733 	iio_device_unregister_sysfs(indio_dev);
1734 error_buffer_free_sysfs:
1735 	iio_buffer_free_sysfs_and_mask(indio_dev);
1736 error_unreg_debugfs:
1737 	iio_device_unregister_debugfs(indio_dev);
1738 	return ret;
1739 }
1740 EXPORT_SYMBOL(__iio_device_register);
1741 
1742 /**
1743  * iio_device_unregister() - unregister a device from the IIO subsystem
1744  * @indio_dev:		Device structure representing the device.
1745  **/
1746 void iio_device_unregister(struct iio_dev *indio_dev)
1747 {
1748 	cdev_device_del(&indio_dev->chrdev, &indio_dev->dev);
1749 
1750 	mutex_lock(&indio_dev->info_exist_lock);
1751 
1752 	iio_device_unregister_debugfs(indio_dev);
1753 
1754 	iio_disable_all_buffers(indio_dev);
1755 
1756 	indio_dev->info = NULL;
1757 
1758 	iio_device_wakeup_eventset(indio_dev);
1759 	iio_buffer_wakeup_poll(indio_dev);
1760 
1761 	mutex_unlock(&indio_dev->info_exist_lock);
1762 
1763 	iio_buffer_free_sysfs_and_mask(indio_dev);
1764 }
1765 EXPORT_SYMBOL(iio_device_unregister);
1766 
1767 static void devm_iio_device_unreg(struct device *dev, void *res)
1768 {
1769 	iio_device_unregister(*(struct iio_dev **)res);
1770 }
1771 
1772 int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
1773 			       struct module *this_mod)
1774 {
1775 	struct iio_dev **ptr;
1776 	int ret;
1777 
1778 	ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1779 	if (!ptr)
1780 		return -ENOMEM;
1781 
1782 	*ptr = indio_dev;
1783 	ret = __iio_device_register(indio_dev, this_mod);
1784 	if (!ret)
1785 		devres_add(dev, ptr);
1786 	else
1787 		devres_free(ptr);
1788 
1789 	return ret;
1790 }
1791 EXPORT_SYMBOL_GPL(__devm_iio_device_register);
1792 
1793 /**
1794  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1795  * @dev:	Device this iio_dev belongs to
1796  * @indio_dev:	the iio_dev associated with the device
1797  *
1798  * Unregister iio_dev registered with devm_iio_device_register().
1799  */
1800 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1801 {
1802 	int rc;
1803 
1804 	rc = devres_release(dev, devm_iio_device_unreg,
1805 			    devm_iio_device_match, indio_dev);
1806 	WARN_ON(rc);
1807 }
1808 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1809 
1810 /**
1811  * iio_device_claim_direct_mode - Keep device in direct mode
1812  * @indio_dev:	the iio_dev associated with the device
1813  *
1814  * If the device is in direct mode it is guaranteed to stay
1815  * that way until iio_device_release_direct_mode() is called.
1816  *
1817  * Use with iio_device_release_direct_mode()
1818  *
1819  * Returns: 0 on success, -EBUSY on failure
1820  */
1821 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1822 {
1823 	mutex_lock(&indio_dev->mlock);
1824 
1825 	if (iio_buffer_enabled(indio_dev)) {
1826 		mutex_unlock(&indio_dev->mlock);
1827 		return -EBUSY;
1828 	}
1829 	return 0;
1830 }
1831 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1832 
1833 /**
1834  * iio_device_release_direct_mode - releases claim on direct mode
1835  * @indio_dev:	the iio_dev associated with the device
1836  *
1837  * Release the claim. Device is no longer guaranteed to stay
1838  * in direct mode.
1839  *
1840  * Use with iio_device_claim_direct_mode()
1841  */
1842 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1843 {
1844 	mutex_unlock(&indio_dev->mlock);
1845 }
1846 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1847 
1848 subsys_initcall(iio_init);
1849 module_exit(iio_exit);
1850 
1851 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1852 MODULE_DESCRIPTION("Industrial I/O core");
1853 MODULE_LICENSE("GPL");
1854