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 };
165 
166 /**
167  * iio_find_channel_from_si() - get channel from its scan index
168  * @indio_dev:		device
169  * @si:			scan index to match
170  */
171 const struct iio_chan_spec
172 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
173 {
174 	int i;
175 
176 	for (i = 0; i < indio_dev->num_channels; i++)
177 		if (indio_dev->channels[i].scan_index == si)
178 			return &indio_dev->channels[i];
179 	return NULL;
180 }
181 
182 /* This turns up an awful lot */
183 ssize_t iio_read_const_attr(struct device *dev,
184 			    struct device_attribute *attr,
185 			    char *buf)
186 {
187 	return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
188 }
189 EXPORT_SYMBOL(iio_read_const_attr);
190 
191 static int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
192 {
193 	int ret;
194 	const struct iio_event_interface *ev_int = indio_dev->event_interface;
195 
196 	ret = mutex_lock_interruptible(&indio_dev->mlock);
197 	if (ret)
198 		return ret;
199 	if ((ev_int && iio_event_enabled(ev_int)) ||
200 	    iio_buffer_enabled(indio_dev)) {
201 		mutex_unlock(&indio_dev->mlock);
202 		return -EBUSY;
203 	}
204 	indio_dev->clock_id = clock_id;
205 	mutex_unlock(&indio_dev->mlock);
206 
207 	return 0;
208 }
209 
210 /**
211  * iio_get_time_ns() - utility function to get a time stamp for events etc
212  * @indio_dev: device
213  */
214 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
215 {
216 	struct timespec64 tp;
217 
218 	switch (iio_device_get_clock(indio_dev)) {
219 	case CLOCK_REALTIME:
220 		return ktime_get_real_ns();
221 	case CLOCK_MONOTONIC:
222 		return ktime_get_ns();
223 	case CLOCK_MONOTONIC_RAW:
224 		return ktime_get_raw_ns();
225 	case CLOCK_REALTIME_COARSE:
226 		return ktime_to_ns(ktime_get_coarse_real());
227 	case CLOCK_MONOTONIC_COARSE:
228 		ktime_get_coarse_ts64(&tp);
229 		return timespec64_to_ns(&tp);
230 	case CLOCK_BOOTTIME:
231 		return ktime_get_boottime_ns();
232 	case CLOCK_TAI:
233 		return ktime_get_clocktai_ns();
234 	default:
235 		BUG();
236 	}
237 }
238 EXPORT_SYMBOL(iio_get_time_ns);
239 
240 /**
241  * iio_get_time_res() - utility function to get time stamp clock resolution in
242  *                      nano seconds.
243  * @indio_dev: device
244  */
245 unsigned int iio_get_time_res(const struct iio_dev *indio_dev)
246 {
247 	switch (iio_device_get_clock(indio_dev)) {
248 	case CLOCK_REALTIME:
249 	case CLOCK_MONOTONIC:
250 	case CLOCK_MONOTONIC_RAW:
251 	case CLOCK_BOOTTIME:
252 	case CLOCK_TAI:
253 		return hrtimer_resolution;
254 	case CLOCK_REALTIME_COARSE:
255 	case CLOCK_MONOTONIC_COARSE:
256 		return LOW_RES_NSEC;
257 	default:
258 		BUG();
259 	}
260 }
261 EXPORT_SYMBOL(iio_get_time_res);
262 
263 static int __init iio_init(void)
264 {
265 	int ret;
266 
267 	/* Register sysfs bus */
268 	ret  = bus_register(&iio_bus_type);
269 	if (ret < 0) {
270 		pr_err("could not register bus type\n");
271 		goto error_nothing;
272 	}
273 
274 	ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
275 	if (ret < 0) {
276 		pr_err("failed to allocate char dev region\n");
277 		goto error_unregister_bus_type;
278 	}
279 
280 	iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
281 
282 	return 0;
283 
284 error_unregister_bus_type:
285 	bus_unregister(&iio_bus_type);
286 error_nothing:
287 	return ret;
288 }
289 
290 static void __exit iio_exit(void)
291 {
292 	if (iio_devt)
293 		unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
294 	bus_unregister(&iio_bus_type);
295 	debugfs_remove(iio_debugfs_dentry);
296 }
297 
298 #if defined(CONFIG_DEBUG_FS)
299 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
300 			      size_t count, loff_t *ppos)
301 {
302 	struct iio_dev *indio_dev = file->private_data;
303 	char buf[20];
304 	unsigned val = 0;
305 	ssize_t len;
306 	int ret;
307 
308 	ret = indio_dev->info->debugfs_reg_access(indio_dev,
309 						  indio_dev->cached_reg_addr,
310 						  0, &val);
311 	if (ret) {
312 		dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
313 		return ret;
314 	}
315 
316 	len = snprintf(buf, sizeof(buf), "0x%X\n", val);
317 
318 	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
319 }
320 
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 void iio_device_register_debugfs(struct iio_dev *indio_dev)
370 {
371 	if (indio_dev->info->debugfs_reg_access == NULL)
372 		return;
373 
374 	if (!iio_debugfs_dentry)
375 		return;
376 
377 	indio_dev->debugfs_dentry =
378 		debugfs_create_dir(dev_name(&indio_dev->dev),
379 				   iio_debugfs_dentry);
380 
381 	debugfs_create_file("direct_reg_access", 0644,
382 			    indio_dev->debugfs_dentry, indio_dev,
383 			    &iio_debugfs_reg_fops);
384 }
385 #else
386 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
387 {
388 }
389 
390 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
391 {
392 }
393 #endif /* CONFIG_DEBUG_FS */
394 
395 static ssize_t iio_read_channel_ext_info(struct device *dev,
396 				     struct device_attribute *attr,
397 				     char *buf)
398 {
399 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
400 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
401 	const struct iio_chan_spec_ext_info *ext_info;
402 
403 	ext_info = &this_attr->c->ext_info[this_attr->address];
404 
405 	return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
406 }
407 
408 static ssize_t iio_write_channel_ext_info(struct device *dev,
409 				     struct device_attribute *attr,
410 				     const char *buf,
411 					 size_t len)
412 {
413 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
414 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
415 	const struct iio_chan_spec_ext_info *ext_info;
416 
417 	ext_info = &this_attr->c->ext_info[this_attr->address];
418 
419 	return ext_info->write(indio_dev, ext_info->private,
420 			       this_attr->c, buf, len);
421 }
422 
423 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
424 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
425 {
426 	const struct iio_enum *e = (const struct iio_enum *)priv;
427 	unsigned int i;
428 	size_t len = 0;
429 
430 	if (!e->num_items)
431 		return 0;
432 
433 	for (i = 0; i < e->num_items; ++i)
434 		len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
435 
436 	/* replace last space with a newline */
437 	buf[len - 1] = '\n';
438 
439 	return len;
440 }
441 EXPORT_SYMBOL_GPL(iio_enum_available_read);
442 
443 ssize_t iio_enum_read(struct iio_dev *indio_dev,
444 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
445 {
446 	const struct iio_enum *e = (const struct iio_enum *)priv;
447 	int i;
448 
449 	if (!e->get)
450 		return -EINVAL;
451 
452 	i = e->get(indio_dev, chan);
453 	if (i < 0)
454 		return i;
455 	else if (i >= e->num_items)
456 		return -EINVAL;
457 
458 	return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
459 }
460 EXPORT_SYMBOL_GPL(iio_enum_read);
461 
462 ssize_t iio_enum_write(struct iio_dev *indio_dev,
463 	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
464 	size_t len)
465 {
466 	const struct iio_enum *e = (const struct iio_enum *)priv;
467 	int ret;
468 
469 	if (!e->set)
470 		return -EINVAL;
471 
472 	ret = __sysfs_match_string(e->items, e->num_items, buf);
473 	if (ret < 0)
474 		return ret;
475 
476 	ret = e->set(indio_dev, chan, ret);
477 	return ret ? ret : len;
478 }
479 EXPORT_SYMBOL_GPL(iio_enum_write);
480 
481 static const struct iio_mount_matrix iio_mount_idmatrix = {
482 	.rotation = {
483 		"1", "0", "0",
484 		"0", "1", "0",
485 		"0", "0", "1"
486 	}
487 };
488 
489 static int iio_setup_mount_idmatrix(const struct device *dev,
490 				    struct iio_mount_matrix *matrix)
491 {
492 	*matrix = iio_mount_idmatrix;
493 	dev_info(dev, "mounting matrix not found: using identity...\n");
494 	return 0;
495 }
496 
497 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
498 			      const struct iio_chan_spec *chan, char *buf)
499 {
500 	const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
501 					      priv)(indio_dev, chan);
502 
503 	if (IS_ERR(mtx))
504 		return PTR_ERR(mtx);
505 
506 	if (!mtx)
507 		mtx = &iio_mount_idmatrix;
508 
509 	return snprintf(buf, PAGE_SIZE, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
510 			mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
511 			mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
512 			mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
513 }
514 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
515 
516 /**
517  * iio_read_mount_matrix() - retrieve iio device mounting matrix from
518  *                           device "mount-matrix" property
519  * @dev:	device the mounting matrix property is assigned to
520  * @propname:	device specific mounting matrix property name
521  * @matrix:	where to store retrieved matrix
522  *
523  * If device is assigned no mounting matrix property, a default 3x3 identity
524  * matrix will be filled in.
525  *
526  * Return: 0 if success, or a negative error code on failure.
527  */
528 int iio_read_mount_matrix(struct device *dev, const char *propname,
529 			  struct iio_mount_matrix *matrix)
530 {
531 	size_t len = ARRAY_SIZE(iio_mount_idmatrix.rotation);
532 	int err;
533 
534 	err = device_property_read_string_array(dev, propname,
535 						matrix->rotation, len);
536 	if (err == len)
537 		return 0;
538 
539 	if (err >= 0)
540 		/* Invalid number of matrix entries. */
541 		return -EINVAL;
542 
543 	if (err != -EINVAL)
544 		/* Invalid matrix declaration format. */
545 		return err;
546 
547 	/* Matrix was not declared at all: fallback to identity. */
548 	return iio_setup_mount_idmatrix(dev, matrix);
549 }
550 EXPORT_SYMBOL(iio_read_mount_matrix);
551 
552 static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
553 				  int size, const int *vals)
554 {
555 	unsigned long long tmp;
556 	int tmp0, tmp1;
557 	bool scale_db = false;
558 
559 	switch (type) {
560 	case IIO_VAL_INT:
561 		return snprintf(buf, len, "%d", vals[0]);
562 	case IIO_VAL_INT_PLUS_MICRO_DB:
563 		scale_db = true;
564 		/* fall through */
565 	case IIO_VAL_INT_PLUS_MICRO:
566 		if (vals[1] < 0)
567 			return snprintf(buf, len, "-%d.%06u%s", abs(vals[0]),
568 					-vals[1], scale_db ? " dB" : "");
569 		else
570 			return snprintf(buf, len, "%d.%06u%s", vals[0], vals[1],
571 					scale_db ? " dB" : "");
572 	case IIO_VAL_INT_PLUS_NANO:
573 		if (vals[1] < 0)
574 			return snprintf(buf, len, "-%d.%09u", abs(vals[0]),
575 					-vals[1]);
576 		else
577 			return snprintf(buf, len, "%d.%09u", vals[0], vals[1]);
578 	case IIO_VAL_FRACTIONAL:
579 		tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
580 		tmp1 = vals[1];
581 		tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1);
582 		return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
583 	case IIO_VAL_FRACTIONAL_LOG2:
584 		tmp = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
585 		tmp0 = (int)div_s64_rem(tmp, 1000000000LL, &tmp1);
586 		return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
587 	case IIO_VAL_INT_MULTIPLE:
588 	{
589 		int i;
590 		int l = 0;
591 
592 		for (i = 0; i < size; ++i) {
593 			l += snprintf(&buf[l], len - l, "%d ", vals[i]);
594 			if (l >= len)
595 				break;
596 		}
597 		return l;
598 	}
599 	default:
600 		return 0;
601 	}
602 }
603 
604 /**
605  * iio_format_value() - Formats a IIO value into its string representation
606  * @buf:	The buffer to which the formatted value gets written
607  *		which is assumed to be big enough (i.e. PAGE_SIZE).
608  * @type:	One of the IIO_VAL_* constants. This decides how the val
609  *		and val2 parameters are formatted.
610  * @size:	Number of IIO value entries contained in vals
611  * @vals:	Pointer to the values, exact meaning depends on the
612  *		type parameter.
613  *
614  * Return: 0 by default, a negative number on failure or the
615  *	   total number of characters written for a type that belongs
616  *	   to the IIO_VAL_* constant.
617  */
618 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
619 {
620 	ssize_t len;
621 
622 	len = __iio_format_value(buf, PAGE_SIZE, type, size, vals);
623 	if (len >= PAGE_SIZE - 1)
624 		return -EFBIG;
625 
626 	return len + sprintf(buf + len, "\n");
627 }
628 EXPORT_SYMBOL_GPL(iio_format_value);
629 
630 static ssize_t iio_read_channel_info(struct device *dev,
631 				     struct device_attribute *attr,
632 				     char *buf)
633 {
634 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
635 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
636 	int vals[INDIO_MAX_RAW_ELEMENTS];
637 	int ret;
638 	int val_len = 2;
639 
640 	if (indio_dev->info->read_raw_multi)
641 		ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
642 							INDIO_MAX_RAW_ELEMENTS,
643 							vals, &val_len,
644 							this_attr->address);
645 	else
646 		ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
647 				    &vals[0], &vals[1], this_attr->address);
648 
649 	if (ret < 0)
650 		return ret;
651 
652 	return iio_format_value(buf, ret, val_len, vals);
653 }
654 
655 static ssize_t iio_format_avail_list(char *buf, const int *vals,
656 				     int type, int length)
657 {
658 	int i;
659 	ssize_t len = 0;
660 
661 	switch (type) {
662 	case IIO_VAL_INT:
663 		for (i = 0; i < length; i++) {
664 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
665 						  type, 1, &vals[i]);
666 			if (len >= PAGE_SIZE)
667 				return -EFBIG;
668 			if (i < length - 1)
669 				len += snprintf(buf + len, PAGE_SIZE - len,
670 						" ");
671 			else
672 				len += snprintf(buf + len, PAGE_SIZE - len,
673 						"\n");
674 			if (len >= PAGE_SIZE)
675 				return -EFBIG;
676 		}
677 		break;
678 	default:
679 		for (i = 0; i < length / 2; i++) {
680 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
681 						  type, 2, &vals[i * 2]);
682 			if (len >= PAGE_SIZE)
683 				return -EFBIG;
684 			if (i < length / 2 - 1)
685 				len += snprintf(buf + len, PAGE_SIZE - len,
686 						" ");
687 			else
688 				len += snprintf(buf + len, PAGE_SIZE - len,
689 						"\n");
690 			if (len >= PAGE_SIZE)
691 				return -EFBIG;
692 		}
693 	}
694 
695 	return len;
696 }
697 
698 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
699 {
700 	int i;
701 	ssize_t len;
702 
703 	len = snprintf(buf, PAGE_SIZE, "[");
704 	switch (type) {
705 	case IIO_VAL_INT:
706 		for (i = 0; i < 3; i++) {
707 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
708 						  type, 1, &vals[i]);
709 			if (len >= PAGE_SIZE)
710 				return -EFBIG;
711 			if (i < 2)
712 				len += snprintf(buf + len, PAGE_SIZE - len,
713 						" ");
714 			else
715 				len += snprintf(buf + len, PAGE_SIZE - len,
716 						"]\n");
717 			if (len >= PAGE_SIZE)
718 				return -EFBIG;
719 		}
720 		break;
721 	default:
722 		for (i = 0; i < 3; i++) {
723 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
724 						  type, 2, &vals[i * 2]);
725 			if (len >= PAGE_SIZE)
726 				return -EFBIG;
727 			if (i < 2)
728 				len += snprintf(buf + len, PAGE_SIZE - len,
729 						" ");
730 			else
731 				len += snprintf(buf + len, PAGE_SIZE - len,
732 						"]\n");
733 			if (len >= PAGE_SIZE)
734 				return -EFBIG;
735 		}
736 	}
737 
738 	return len;
739 }
740 
741 static ssize_t iio_read_channel_info_avail(struct device *dev,
742 					   struct device_attribute *attr,
743 					   char *buf)
744 {
745 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
746 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
747 	const int *vals;
748 	int ret;
749 	int length;
750 	int type;
751 
752 	ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
753 					  &vals, &type, &length,
754 					  this_attr->address);
755 
756 	if (ret < 0)
757 		return ret;
758 	switch (ret) {
759 	case IIO_AVAIL_LIST:
760 		return iio_format_avail_list(buf, vals, type, length);
761 	case IIO_AVAIL_RANGE:
762 		return iio_format_avail_range(buf, vals, type);
763 	default:
764 		return -EINVAL;
765 	}
766 }
767 
768 /**
769  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
770  * @str: The string to parse
771  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
772  * @integer: The integer part of the number
773  * @fract: The fractional part of the number
774  *
775  * Returns 0 on success, or a negative error code if the string could not be
776  * parsed.
777  */
778 int iio_str_to_fixpoint(const char *str, int fract_mult,
779 	int *integer, int *fract)
780 {
781 	int i = 0, f = 0;
782 	bool integer_part = true, negative = false;
783 
784 	if (fract_mult == 0) {
785 		*fract = 0;
786 
787 		return kstrtoint(str, 0, integer);
788 	}
789 
790 	if (str[0] == '-') {
791 		negative = true;
792 		str++;
793 	} else if (str[0] == '+') {
794 		str++;
795 	}
796 
797 	while (*str) {
798 		if ('0' <= *str && *str <= '9') {
799 			if (integer_part) {
800 				i = i * 10 + *str - '0';
801 			} else {
802 				f += fract_mult * (*str - '0');
803 				fract_mult /= 10;
804 			}
805 		} else if (*str == '\n') {
806 			if (*(str + 1) == '\0')
807 				break;
808 			else
809 				return -EINVAL;
810 		} else if (*str == '.' && integer_part) {
811 			integer_part = false;
812 		} else {
813 			return -EINVAL;
814 		}
815 		str++;
816 	}
817 
818 	if (negative) {
819 		if (i)
820 			i = -i;
821 		else
822 			f = -f;
823 	}
824 
825 	*integer = i;
826 	*fract = f;
827 
828 	return 0;
829 }
830 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
831 
832 static ssize_t iio_write_channel_info(struct device *dev,
833 				      struct device_attribute *attr,
834 				      const char *buf,
835 				      size_t len)
836 {
837 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
838 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
839 	int ret, fract_mult = 100000;
840 	int integer, fract;
841 
842 	/* Assumes decimal - precision based on number of digits */
843 	if (!indio_dev->info->write_raw)
844 		return -EINVAL;
845 
846 	if (indio_dev->info->write_raw_get_fmt)
847 		switch (indio_dev->info->write_raw_get_fmt(indio_dev,
848 			this_attr->c, this_attr->address)) {
849 		case IIO_VAL_INT:
850 			fract_mult = 0;
851 			break;
852 		case IIO_VAL_INT_PLUS_MICRO:
853 			fract_mult = 100000;
854 			break;
855 		case IIO_VAL_INT_PLUS_NANO:
856 			fract_mult = 100000000;
857 			break;
858 		default:
859 			return -EINVAL;
860 		}
861 
862 	ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
863 	if (ret)
864 		return ret;
865 
866 	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
867 					 integer, fract, this_attr->address);
868 	if (ret)
869 		return ret;
870 
871 	return len;
872 }
873 
874 static
875 int __iio_device_attr_init(struct device_attribute *dev_attr,
876 			   const char *postfix,
877 			   struct iio_chan_spec const *chan,
878 			   ssize_t (*readfunc)(struct device *dev,
879 					       struct device_attribute *attr,
880 					       char *buf),
881 			   ssize_t (*writefunc)(struct device *dev,
882 						struct device_attribute *attr,
883 						const char *buf,
884 						size_t len),
885 			   enum iio_shared_by shared_by)
886 {
887 	int ret = 0;
888 	char *name = NULL;
889 	char *full_postfix;
890 	sysfs_attr_init(&dev_attr->attr);
891 
892 	/* Build up postfix of <extend_name>_<modifier>_postfix */
893 	if (chan->modified && (shared_by == IIO_SEPARATE)) {
894 		if (chan->extend_name)
895 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
896 						 iio_modifier_names[chan
897 								    ->channel2],
898 						 chan->extend_name,
899 						 postfix);
900 		else
901 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
902 						 iio_modifier_names[chan
903 								    ->channel2],
904 						 postfix);
905 	} else {
906 		if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
907 			full_postfix = kstrdup(postfix, GFP_KERNEL);
908 		else
909 			full_postfix = kasprintf(GFP_KERNEL,
910 						 "%s_%s",
911 						 chan->extend_name,
912 						 postfix);
913 	}
914 	if (full_postfix == NULL)
915 		return -ENOMEM;
916 
917 	if (chan->differential) { /* Differential can not have modifier */
918 		switch (shared_by) {
919 		case IIO_SHARED_BY_ALL:
920 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
921 			break;
922 		case IIO_SHARED_BY_DIR:
923 			name = kasprintf(GFP_KERNEL, "%s_%s",
924 						iio_direction[chan->output],
925 						full_postfix);
926 			break;
927 		case IIO_SHARED_BY_TYPE:
928 			name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
929 					    iio_direction[chan->output],
930 					    iio_chan_type_name_spec[chan->type],
931 					    iio_chan_type_name_spec[chan->type],
932 					    full_postfix);
933 			break;
934 		case IIO_SEPARATE:
935 			if (!chan->indexed) {
936 				WARN(1, "Differential channels must be indexed\n");
937 				ret = -EINVAL;
938 				goto error_free_full_postfix;
939 			}
940 			name = kasprintf(GFP_KERNEL,
941 					    "%s_%s%d-%s%d_%s",
942 					    iio_direction[chan->output],
943 					    iio_chan_type_name_spec[chan->type],
944 					    chan->channel,
945 					    iio_chan_type_name_spec[chan->type],
946 					    chan->channel2,
947 					    full_postfix);
948 			break;
949 		}
950 	} else { /* Single ended */
951 		switch (shared_by) {
952 		case IIO_SHARED_BY_ALL:
953 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
954 			break;
955 		case IIO_SHARED_BY_DIR:
956 			name = kasprintf(GFP_KERNEL, "%s_%s",
957 						iio_direction[chan->output],
958 						full_postfix);
959 			break;
960 		case IIO_SHARED_BY_TYPE:
961 			name = kasprintf(GFP_KERNEL, "%s_%s_%s",
962 					    iio_direction[chan->output],
963 					    iio_chan_type_name_spec[chan->type],
964 					    full_postfix);
965 			break;
966 
967 		case IIO_SEPARATE:
968 			if (chan->indexed)
969 				name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
970 						    iio_direction[chan->output],
971 						    iio_chan_type_name_spec[chan->type],
972 						    chan->channel,
973 						    full_postfix);
974 			else
975 				name = kasprintf(GFP_KERNEL, "%s_%s_%s",
976 						    iio_direction[chan->output],
977 						    iio_chan_type_name_spec[chan->type],
978 						    full_postfix);
979 			break;
980 		}
981 	}
982 	if (name == NULL) {
983 		ret = -ENOMEM;
984 		goto error_free_full_postfix;
985 	}
986 	dev_attr->attr.name = name;
987 
988 	if (readfunc) {
989 		dev_attr->attr.mode |= S_IRUGO;
990 		dev_attr->show = readfunc;
991 	}
992 
993 	if (writefunc) {
994 		dev_attr->attr.mode |= S_IWUSR;
995 		dev_attr->store = writefunc;
996 	}
997 
998 error_free_full_postfix:
999 	kfree(full_postfix);
1000 
1001 	return ret;
1002 }
1003 
1004 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1005 {
1006 	kfree(dev_attr->attr.name);
1007 }
1008 
1009 int __iio_add_chan_devattr(const char *postfix,
1010 			   struct iio_chan_spec const *chan,
1011 			   ssize_t (*readfunc)(struct device *dev,
1012 					       struct device_attribute *attr,
1013 					       char *buf),
1014 			   ssize_t (*writefunc)(struct device *dev,
1015 						struct device_attribute *attr,
1016 						const char *buf,
1017 						size_t len),
1018 			   u64 mask,
1019 			   enum iio_shared_by shared_by,
1020 			   struct device *dev,
1021 			   struct list_head *attr_list)
1022 {
1023 	int ret;
1024 	struct iio_dev_attr *iio_attr, *t;
1025 
1026 	iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1027 	if (iio_attr == NULL)
1028 		return -ENOMEM;
1029 	ret = __iio_device_attr_init(&iio_attr->dev_attr,
1030 				     postfix, chan,
1031 				     readfunc, writefunc, shared_by);
1032 	if (ret)
1033 		goto error_iio_dev_attr_free;
1034 	iio_attr->c = chan;
1035 	iio_attr->address = mask;
1036 	list_for_each_entry(t, attr_list, l)
1037 		if (strcmp(t->dev_attr.attr.name,
1038 			   iio_attr->dev_attr.attr.name) == 0) {
1039 			if (shared_by == IIO_SEPARATE)
1040 				dev_err(dev, "tried to double register : %s\n",
1041 					t->dev_attr.attr.name);
1042 			ret = -EBUSY;
1043 			goto error_device_attr_deinit;
1044 		}
1045 	list_add(&iio_attr->l, attr_list);
1046 
1047 	return 0;
1048 
1049 error_device_attr_deinit:
1050 	__iio_device_attr_deinit(&iio_attr->dev_attr);
1051 error_iio_dev_attr_free:
1052 	kfree(iio_attr);
1053 	return ret;
1054 }
1055 
1056 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1057 					 struct iio_chan_spec const *chan,
1058 					 enum iio_shared_by shared_by,
1059 					 const long *infomask)
1060 {
1061 	int i, ret, attrcount = 0;
1062 
1063 	for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1064 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1065 			return -EINVAL;
1066 		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1067 					     chan,
1068 					     &iio_read_channel_info,
1069 					     &iio_write_channel_info,
1070 					     i,
1071 					     shared_by,
1072 					     &indio_dev->dev,
1073 					     &indio_dev->channel_attr_list);
1074 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1075 			continue;
1076 		else if (ret < 0)
1077 			return ret;
1078 		attrcount++;
1079 	}
1080 
1081 	return attrcount;
1082 }
1083 
1084 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1085 					       struct iio_chan_spec const *chan,
1086 					       enum iio_shared_by shared_by,
1087 					       const long *infomask)
1088 {
1089 	int i, ret, attrcount = 0;
1090 	char *avail_postfix;
1091 
1092 	for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1093 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1094 			return -EINVAL;
1095 		avail_postfix = kasprintf(GFP_KERNEL,
1096 					  "%s_available",
1097 					  iio_chan_info_postfix[i]);
1098 		if (!avail_postfix)
1099 			return -ENOMEM;
1100 
1101 		ret = __iio_add_chan_devattr(avail_postfix,
1102 					     chan,
1103 					     &iio_read_channel_info_avail,
1104 					     NULL,
1105 					     i,
1106 					     shared_by,
1107 					     &indio_dev->dev,
1108 					     &indio_dev->channel_attr_list);
1109 		kfree(avail_postfix);
1110 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1111 			continue;
1112 		else if (ret < 0)
1113 			return ret;
1114 		attrcount++;
1115 	}
1116 
1117 	return attrcount;
1118 }
1119 
1120 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1121 					struct iio_chan_spec const *chan)
1122 {
1123 	int ret, attrcount = 0;
1124 	const struct iio_chan_spec_ext_info *ext_info;
1125 
1126 	if (chan->channel < 0)
1127 		return 0;
1128 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1129 					    IIO_SEPARATE,
1130 					    &chan->info_mask_separate);
1131 	if (ret < 0)
1132 		return ret;
1133 	attrcount += ret;
1134 
1135 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1136 						  IIO_SEPARATE,
1137 						  &chan->
1138 						  info_mask_separate_available);
1139 	if (ret < 0)
1140 		return ret;
1141 	attrcount += ret;
1142 
1143 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1144 					    IIO_SHARED_BY_TYPE,
1145 					    &chan->info_mask_shared_by_type);
1146 	if (ret < 0)
1147 		return ret;
1148 	attrcount += ret;
1149 
1150 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1151 						  IIO_SHARED_BY_TYPE,
1152 						  &chan->
1153 						  info_mask_shared_by_type_available);
1154 	if (ret < 0)
1155 		return ret;
1156 	attrcount += ret;
1157 
1158 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1159 					    IIO_SHARED_BY_DIR,
1160 					    &chan->info_mask_shared_by_dir);
1161 	if (ret < 0)
1162 		return ret;
1163 	attrcount += ret;
1164 
1165 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1166 						  IIO_SHARED_BY_DIR,
1167 						  &chan->info_mask_shared_by_dir_available);
1168 	if (ret < 0)
1169 		return ret;
1170 	attrcount += ret;
1171 
1172 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1173 					    IIO_SHARED_BY_ALL,
1174 					    &chan->info_mask_shared_by_all);
1175 	if (ret < 0)
1176 		return ret;
1177 	attrcount += ret;
1178 
1179 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1180 						  IIO_SHARED_BY_ALL,
1181 						  &chan->info_mask_shared_by_all_available);
1182 	if (ret < 0)
1183 		return ret;
1184 	attrcount += ret;
1185 
1186 	if (chan->ext_info) {
1187 		unsigned int i = 0;
1188 		for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1189 			ret = __iio_add_chan_devattr(ext_info->name,
1190 					chan,
1191 					ext_info->read ?
1192 					    &iio_read_channel_ext_info : NULL,
1193 					ext_info->write ?
1194 					    &iio_write_channel_ext_info : NULL,
1195 					i,
1196 					ext_info->shared,
1197 					&indio_dev->dev,
1198 					&indio_dev->channel_attr_list);
1199 			i++;
1200 			if (ret == -EBUSY && ext_info->shared)
1201 				continue;
1202 
1203 			if (ret)
1204 				return ret;
1205 
1206 			attrcount++;
1207 		}
1208 	}
1209 
1210 	return attrcount;
1211 }
1212 
1213 /**
1214  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1215  * @attr_list: List of IIO device attributes
1216  *
1217  * This function frees the memory allocated for each of the IIO device
1218  * attributes in the list.
1219  */
1220 void iio_free_chan_devattr_list(struct list_head *attr_list)
1221 {
1222 	struct iio_dev_attr *p, *n;
1223 
1224 	list_for_each_entry_safe(p, n, attr_list, l) {
1225 		kfree(p->dev_attr.attr.name);
1226 		list_del(&p->l);
1227 		kfree(p);
1228 	}
1229 }
1230 
1231 static ssize_t iio_show_dev_name(struct device *dev,
1232 				 struct device_attribute *attr,
1233 				 char *buf)
1234 {
1235 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1236 	return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
1237 }
1238 
1239 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
1240 
1241 static ssize_t iio_show_dev_label(struct device *dev,
1242 				 struct device_attribute *attr,
1243 				 char *buf)
1244 {
1245 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1246 	return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->label);
1247 }
1248 
1249 static DEVICE_ATTR(label, S_IRUGO, iio_show_dev_label, NULL);
1250 
1251 static ssize_t iio_show_timestamp_clock(struct device *dev,
1252 					struct device_attribute *attr,
1253 					char *buf)
1254 {
1255 	const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1256 	const clockid_t clk = iio_device_get_clock(indio_dev);
1257 	const char *name;
1258 	ssize_t sz;
1259 
1260 	switch (clk) {
1261 	case CLOCK_REALTIME:
1262 		name = "realtime\n";
1263 		sz = sizeof("realtime\n");
1264 		break;
1265 	case CLOCK_MONOTONIC:
1266 		name = "monotonic\n";
1267 		sz = sizeof("monotonic\n");
1268 		break;
1269 	case CLOCK_MONOTONIC_RAW:
1270 		name = "monotonic_raw\n";
1271 		sz = sizeof("monotonic_raw\n");
1272 		break;
1273 	case CLOCK_REALTIME_COARSE:
1274 		name = "realtime_coarse\n";
1275 		sz = sizeof("realtime_coarse\n");
1276 		break;
1277 	case CLOCK_MONOTONIC_COARSE:
1278 		name = "monotonic_coarse\n";
1279 		sz = sizeof("monotonic_coarse\n");
1280 		break;
1281 	case CLOCK_BOOTTIME:
1282 		name = "boottime\n";
1283 		sz = sizeof("boottime\n");
1284 		break;
1285 	case CLOCK_TAI:
1286 		name = "tai\n";
1287 		sz = sizeof("tai\n");
1288 		break;
1289 	default:
1290 		BUG();
1291 	}
1292 
1293 	memcpy(buf, name, sz);
1294 	return sz;
1295 }
1296 
1297 static ssize_t iio_store_timestamp_clock(struct device *dev,
1298 					 struct device_attribute *attr,
1299 					 const char *buf, size_t len)
1300 {
1301 	clockid_t clk;
1302 	int ret;
1303 
1304 	if (sysfs_streq(buf, "realtime"))
1305 		clk = CLOCK_REALTIME;
1306 	else if (sysfs_streq(buf, "monotonic"))
1307 		clk = CLOCK_MONOTONIC;
1308 	else if (sysfs_streq(buf, "monotonic_raw"))
1309 		clk = CLOCK_MONOTONIC_RAW;
1310 	else if (sysfs_streq(buf, "realtime_coarse"))
1311 		clk = CLOCK_REALTIME_COARSE;
1312 	else if (sysfs_streq(buf, "monotonic_coarse"))
1313 		clk = CLOCK_MONOTONIC_COARSE;
1314 	else if (sysfs_streq(buf, "boottime"))
1315 		clk = CLOCK_BOOTTIME;
1316 	else if (sysfs_streq(buf, "tai"))
1317 		clk = CLOCK_TAI;
1318 	else
1319 		return -EINVAL;
1320 
1321 	ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1322 	if (ret)
1323 		return ret;
1324 
1325 	return len;
1326 }
1327 
1328 static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1329 		   iio_show_timestamp_clock, iio_store_timestamp_clock);
1330 
1331 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1332 {
1333 	int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1334 	struct iio_dev_attr *p;
1335 	struct attribute **attr, *clk = NULL;
1336 
1337 	/* First count elements in any existing group */
1338 	if (indio_dev->info->attrs) {
1339 		attr = indio_dev->info->attrs->attrs;
1340 		while (*attr++ != NULL)
1341 			attrcount_orig++;
1342 	}
1343 	attrcount = attrcount_orig;
1344 	/*
1345 	 * New channel registration method - relies on the fact a group does
1346 	 * not need to be initialized if its name is NULL.
1347 	 */
1348 	if (indio_dev->channels)
1349 		for (i = 0; i < indio_dev->num_channels; i++) {
1350 			const struct iio_chan_spec *chan =
1351 				&indio_dev->channels[i];
1352 
1353 			if (chan->type == IIO_TIMESTAMP)
1354 				clk = &dev_attr_current_timestamp_clock.attr;
1355 
1356 			ret = iio_device_add_channel_sysfs(indio_dev, chan);
1357 			if (ret < 0)
1358 				goto error_clear_attrs;
1359 			attrcount += ret;
1360 		}
1361 
1362 	if (indio_dev->event_interface)
1363 		clk = &dev_attr_current_timestamp_clock.attr;
1364 
1365 	if (indio_dev->name)
1366 		attrcount++;
1367 	if (indio_dev->label)
1368 		attrcount++;
1369 	if (clk)
1370 		attrcount++;
1371 
1372 	indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
1373 						   sizeof(indio_dev->chan_attr_group.attrs[0]),
1374 						   GFP_KERNEL);
1375 	if (indio_dev->chan_attr_group.attrs == NULL) {
1376 		ret = -ENOMEM;
1377 		goto error_clear_attrs;
1378 	}
1379 	/* Copy across original attributes */
1380 	if (indio_dev->info->attrs)
1381 		memcpy(indio_dev->chan_attr_group.attrs,
1382 		       indio_dev->info->attrs->attrs,
1383 		       sizeof(indio_dev->chan_attr_group.attrs[0])
1384 		       *attrcount_orig);
1385 	attrn = attrcount_orig;
1386 	/* Add all elements from the list. */
1387 	list_for_each_entry(p, &indio_dev->channel_attr_list, l)
1388 		indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1389 	if (indio_dev->name)
1390 		indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1391 	if (indio_dev->label)
1392 		indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_label.attr;
1393 	if (clk)
1394 		indio_dev->chan_attr_group.attrs[attrn++] = clk;
1395 
1396 	indio_dev->groups[indio_dev->groupcounter++] =
1397 		&indio_dev->chan_attr_group;
1398 
1399 	return 0;
1400 
1401 error_clear_attrs:
1402 	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1403 
1404 	return ret;
1405 }
1406 
1407 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1408 {
1409 
1410 	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1411 	kfree(indio_dev->chan_attr_group.attrs);
1412 	indio_dev->chan_attr_group.attrs = NULL;
1413 }
1414 
1415 static void iio_dev_release(struct device *device)
1416 {
1417 	struct iio_dev *indio_dev = dev_to_iio_dev(device);
1418 	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1419 		iio_device_unregister_trigger_consumer(indio_dev);
1420 	iio_device_unregister_eventset(indio_dev);
1421 	iio_device_unregister_sysfs(indio_dev);
1422 
1423 	iio_buffer_put(indio_dev->buffer);
1424 
1425 	ida_simple_remove(&iio_ida, indio_dev->id);
1426 	kfree(indio_dev);
1427 }
1428 
1429 struct device_type iio_device_type = {
1430 	.name = "iio_device",
1431 	.release = iio_dev_release,
1432 };
1433 
1434 /**
1435  * iio_device_alloc() - allocate an iio_dev from a driver
1436  * @sizeof_priv:	Space to allocate for private structure.
1437  **/
1438 struct iio_dev *iio_device_alloc(int sizeof_priv)
1439 {
1440 	struct iio_dev *dev;
1441 	size_t alloc_size;
1442 
1443 	alloc_size = sizeof(struct iio_dev);
1444 	if (sizeof_priv) {
1445 		alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1446 		alloc_size += sizeof_priv;
1447 	}
1448 	/* ensure 32-byte alignment of whole construct ? */
1449 	alloc_size += IIO_ALIGN - 1;
1450 
1451 	dev = kzalloc(alloc_size, GFP_KERNEL);
1452 
1453 	if (dev) {
1454 		dev->dev.groups = dev->groups;
1455 		dev->dev.type = &iio_device_type;
1456 		dev->dev.bus = &iio_bus_type;
1457 		device_initialize(&dev->dev);
1458 		dev_set_drvdata(&dev->dev, (void *)dev);
1459 		mutex_init(&dev->mlock);
1460 		mutex_init(&dev->info_exist_lock);
1461 		INIT_LIST_HEAD(&dev->channel_attr_list);
1462 
1463 		dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1464 		if (dev->id < 0) {
1465 			/* cannot use a dev_err as the name isn't available */
1466 			pr_err("failed to get device id\n");
1467 			kfree(dev);
1468 			return NULL;
1469 		}
1470 		dev_set_name(&dev->dev, "iio:device%d", dev->id);
1471 		INIT_LIST_HEAD(&dev->buffer_list);
1472 	}
1473 
1474 	return dev;
1475 }
1476 EXPORT_SYMBOL(iio_device_alloc);
1477 
1478 /**
1479  * iio_device_free() - free an iio_dev from a driver
1480  * @dev:		the iio_dev associated with the device
1481  **/
1482 void iio_device_free(struct iio_dev *dev)
1483 {
1484 	if (dev)
1485 		put_device(&dev->dev);
1486 }
1487 EXPORT_SYMBOL(iio_device_free);
1488 
1489 static void devm_iio_device_release(struct device *dev, void *res)
1490 {
1491 	iio_device_free(*(struct iio_dev **)res);
1492 }
1493 
1494 int devm_iio_device_match(struct device *dev, void *res, void *data)
1495 {
1496 	struct iio_dev **r = res;
1497 	if (!r || !*r) {
1498 		WARN_ON(!r || !*r);
1499 		return 0;
1500 	}
1501 	return *r == data;
1502 }
1503 EXPORT_SYMBOL_GPL(devm_iio_device_match);
1504 
1505 /**
1506  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1507  * @dev:		Device to allocate iio_dev for
1508  * @sizeof_priv:	Space to allocate for private structure.
1509  *
1510  * Managed iio_device_alloc. iio_dev allocated with this function is
1511  * automatically freed on driver detach.
1512  *
1513  * If an iio_dev allocated with this function needs to be freed separately,
1514  * devm_iio_device_free() must be used.
1515  *
1516  * RETURNS:
1517  * Pointer to allocated iio_dev on success, NULL on failure.
1518  */
1519 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1520 {
1521 	struct iio_dev **ptr, *iio_dev;
1522 
1523 	ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1524 			   GFP_KERNEL);
1525 	if (!ptr)
1526 		return NULL;
1527 
1528 	iio_dev = iio_device_alloc(sizeof_priv);
1529 	if (iio_dev) {
1530 		*ptr = iio_dev;
1531 		devres_add(dev, ptr);
1532 	} else {
1533 		devres_free(ptr);
1534 	}
1535 
1536 	return iio_dev;
1537 }
1538 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1539 
1540 /**
1541  * devm_iio_device_free - Resource-managed iio_device_free()
1542  * @dev:		Device this iio_dev belongs to
1543  * @iio_dev:		the iio_dev associated with the device
1544  *
1545  * Free iio_dev allocated with devm_iio_device_alloc().
1546  */
1547 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1548 {
1549 	int rc;
1550 
1551 	rc = devres_release(dev, devm_iio_device_release,
1552 			    devm_iio_device_match, iio_dev);
1553 	WARN_ON(rc);
1554 }
1555 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1556 
1557 /**
1558  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1559  * @inode:	Inode structure for identifying the device in the file system
1560  * @filp:	File structure for iio device used to keep and later access
1561  *		private data
1562  *
1563  * Return: 0 on success or -EBUSY if the device is already opened
1564  **/
1565 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1566 {
1567 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1568 						struct iio_dev, chrdev);
1569 
1570 	if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1571 		return -EBUSY;
1572 
1573 	iio_device_get(indio_dev);
1574 
1575 	filp->private_data = indio_dev;
1576 
1577 	return 0;
1578 }
1579 
1580 /**
1581  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1582  * @inode:	Inode structure pointer for the char device
1583  * @filp:	File structure pointer for the char device
1584  *
1585  * Return: 0 for successful release
1586  */
1587 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1588 {
1589 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1590 						struct iio_dev, chrdev);
1591 	clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1592 	iio_device_put(indio_dev);
1593 
1594 	return 0;
1595 }
1596 
1597 /* Somewhat of a cross file organization violation - ioctls here are actually
1598  * event related */
1599 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1600 {
1601 	struct iio_dev *indio_dev = filp->private_data;
1602 	int __user *ip = (int __user *)arg;
1603 	int fd;
1604 
1605 	if (!indio_dev->info)
1606 		return -ENODEV;
1607 
1608 	if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1609 		fd = iio_event_getfd(indio_dev);
1610 		if (fd < 0)
1611 			return fd;
1612 		if (copy_to_user(ip, &fd, sizeof(fd)))
1613 			return -EFAULT;
1614 		return 0;
1615 	}
1616 	return -EINVAL;
1617 }
1618 
1619 static const struct file_operations iio_buffer_fileops = {
1620 	.read = iio_buffer_read_first_n_outer_addr,
1621 	.release = iio_chrdev_release,
1622 	.open = iio_chrdev_open,
1623 	.poll = iio_buffer_poll_addr,
1624 	.owner = THIS_MODULE,
1625 	.llseek = noop_llseek,
1626 	.unlocked_ioctl = iio_ioctl,
1627 	.compat_ioctl = compat_ptr_ioctl,
1628 };
1629 
1630 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1631 {
1632 	int i, j;
1633 	const struct iio_chan_spec *channels = indio_dev->channels;
1634 
1635 	if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1636 		return 0;
1637 
1638 	for (i = 0; i < indio_dev->num_channels - 1; i++) {
1639 		if (channels[i].scan_index < 0)
1640 			continue;
1641 		for (j = i + 1; j < indio_dev->num_channels; j++)
1642 			if (channels[i].scan_index == channels[j].scan_index) {
1643 				dev_err(&indio_dev->dev,
1644 					"Duplicate scan index %d\n",
1645 					channels[i].scan_index);
1646 				return -EINVAL;
1647 			}
1648 	}
1649 
1650 	return 0;
1651 }
1652 
1653 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1654 
1655 int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1656 {
1657 	int ret;
1658 
1659 	indio_dev->driver_module = this_mod;
1660 	/* If the calling driver did not initialize of_node, do it here */
1661 	if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1662 		indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1663 
1664 	indio_dev->label = of_get_property(indio_dev->dev.of_node, "label",
1665 					   NULL);
1666 
1667 	ret = iio_check_unique_scan_index(indio_dev);
1668 	if (ret < 0)
1669 		return ret;
1670 
1671 	if (!indio_dev->info)
1672 		return -EINVAL;
1673 
1674 	/* configure elements for the chrdev */
1675 	indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1676 
1677 	iio_device_register_debugfs(indio_dev);
1678 
1679 	ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1680 	if (ret) {
1681 		dev_err(indio_dev->dev.parent,
1682 			"Failed to create buffer sysfs interfaces\n");
1683 		goto error_unreg_debugfs;
1684 	}
1685 
1686 	ret = iio_device_register_sysfs(indio_dev);
1687 	if (ret) {
1688 		dev_err(indio_dev->dev.parent,
1689 			"Failed to register sysfs interfaces\n");
1690 		goto error_buffer_free_sysfs;
1691 	}
1692 	ret = iio_device_register_eventset(indio_dev);
1693 	if (ret) {
1694 		dev_err(indio_dev->dev.parent,
1695 			"Failed to register event set\n");
1696 		goto error_free_sysfs;
1697 	}
1698 	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1699 		iio_device_register_trigger_consumer(indio_dev);
1700 
1701 	if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1702 		indio_dev->setup_ops == NULL)
1703 		indio_dev->setup_ops = &noop_ring_setup_ops;
1704 
1705 	cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1706 
1707 	indio_dev->chrdev.owner = this_mod;
1708 
1709 	ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev);
1710 	if (ret < 0)
1711 		goto error_unreg_eventset;
1712 
1713 	return 0;
1714 
1715 error_unreg_eventset:
1716 	iio_device_unregister_eventset(indio_dev);
1717 error_free_sysfs:
1718 	iio_device_unregister_sysfs(indio_dev);
1719 error_buffer_free_sysfs:
1720 	iio_buffer_free_sysfs_and_mask(indio_dev);
1721 error_unreg_debugfs:
1722 	iio_device_unregister_debugfs(indio_dev);
1723 	return ret;
1724 }
1725 EXPORT_SYMBOL(__iio_device_register);
1726 
1727 /**
1728  * iio_device_unregister() - unregister a device from the IIO subsystem
1729  * @indio_dev:		Device structure representing the device.
1730  **/
1731 void iio_device_unregister(struct iio_dev *indio_dev)
1732 {
1733 	cdev_device_del(&indio_dev->chrdev, &indio_dev->dev);
1734 
1735 	mutex_lock(&indio_dev->info_exist_lock);
1736 
1737 	iio_device_unregister_debugfs(indio_dev);
1738 
1739 	iio_disable_all_buffers(indio_dev);
1740 
1741 	indio_dev->info = NULL;
1742 
1743 	iio_device_wakeup_eventset(indio_dev);
1744 	iio_buffer_wakeup_poll(indio_dev);
1745 
1746 	mutex_unlock(&indio_dev->info_exist_lock);
1747 
1748 	iio_buffer_free_sysfs_and_mask(indio_dev);
1749 }
1750 EXPORT_SYMBOL(iio_device_unregister);
1751 
1752 static void devm_iio_device_unreg(struct device *dev, void *res)
1753 {
1754 	iio_device_unregister(*(struct iio_dev **)res);
1755 }
1756 
1757 int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
1758 			       struct module *this_mod)
1759 {
1760 	struct iio_dev **ptr;
1761 	int ret;
1762 
1763 	ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1764 	if (!ptr)
1765 		return -ENOMEM;
1766 
1767 	*ptr = indio_dev;
1768 	ret = __iio_device_register(indio_dev, this_mod);
1769 	if (!ret)
1770 		devres_add(dev, ptr);
1771 	else
1772 		devres_free(ptr);
1773 
1774 	return ret;
1775 }
1776 EXPORT_SYMBOL_GPL(__devm_iio_device_register);
1777 
1778 /**
1779  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1780  * @dev:	Device this iio_dev belongs to
1781  * @indio_dev:	the iio_dev associated with the device
1782  *
1783  * Unregister iio_dev registered with devm_iio_device_register().
1784  */
1785 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1786 {
1787 	int rc;
1788 
1789 	rc = devres_release(dev, devm_iio_device_unreg,
1790 			    devm_iio_device_match, indio_dev);
1791 	WARN_ON(rc);
1792 }
1793 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1794 
1795 /**
1796  * iio_device_claim_direct_mode - Keep device in direct mode
1797  * @indio_dev:	the iio_dev associated with the device
1798  *
1799  * If the device is in direct mode it is guaranteed to stay
1800  * that way until iio_device_release_direct_mode() is called.
1801  *
1802  * Use with iio_device_release_direct_mode()
1803  *
1804  * Returns: 0 on success, -EBUSY on failure
1805  */
1806 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1807 {
1808 	mutex_lock(&indio_dev->mlock);
1809 
1810 	if (iio_buffer_enabled(indio_dev)) {
1811 		mutex_unlock(&indio_dev->mlock);
1812 		return -EBUSY;
1813 	}
1814 	return 0;
1815 }
1816 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1817 
1818 /**
1819  * iio_device_release_direct_mode - releases claim on direct mode
1820  * @indio_dev:	the iio_dev associated with the device
1821  *
1822  * Release the claim. Device is no longer guaranteed to stay
1823  * in direct mode.
1824  *
1825  * Use with iio_device_claim_direct_mode()
1826  */
1827 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1828 {
1829 	mutex_unlock(&indio_dev->mlock);
1830 }
1831 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1832 
1833 subsys_initcall(iio_init);
1834 module_exit(iio_exit);
1835 
1836 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1837 MODULE_DESCRIPTION("Industrial I/O core");
1838 MODULE_LICENSE("GPL");
1839