xref: /linux/drivers/iio/industrialio-core.c (revision 31d166642c7c601c65eccf0ff2e0afe9a0538be2)
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_boot_ns();
232 	case CLOCK_TAI:
233 		return ktime_get_tai_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 int iio_device_register_debugfs(struct iio_dev *indio_dev)
370 {
371 	struct dentry *d;
372 
373 	if (indio_dev->info->debugfs_reg_access == NULL)
374 		return 0;
375 
376 	if (!iio_debugfs_dentry)
377 		return 0;
378 
379 	indio_dev->debugfs_dentry =
380 		debugfs_create_dir(dev_name(&indio_dev->dev),
381 				   iio_debugfs_dentry);
382 	if (indio_dev->debugfs_dentry == NULL) {
383 		dev_warn(indio_dev->dev.parent,
384 			 "Failed to create debugfs directory\n");
385 		return -EFAULT;
386 	}
387 
388 	d = debugfs_create_file("direct_reg_access", 0644,
389 				indio_dev->debugfs_dentry,
390 				indio_dev, &iio_debugfs_reg_fops);
391 	if (!d) {
392 		iio_device_unregister_debugfs(indio_dev);
393 		return -ENOMEM;
394 	}
395 
396 	return 0;
397 }
398 #else
399 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
400 {
401 	return 0;
402 }
403 
404 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
405 {
406 }
407 #endif /* CONFIG_DEBUG_FS */
408 
409 static ssize_t iio_read_channel_ext_info(struct device *dev,
410 				     struct device_attribute *attr,
411 				     char *buf)
412 {
413 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
414 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
415 	const struct iio_chan_spec_ext_info *ext_info;
416 
417 	ext_info = &this_attr->c->ext_info[this_attr->address];
418 
419 	return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
420 }
421 
422 static ssize_t iio_write_channel_ext_info(struct device *dev,
423 				     struct device_attribute *attr,
424 				     const char *buf,
425 					 size_t len)
426 {
427 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
428 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
429 	const struct iio_chan_spec_ext_info *ext_info;
430 
431 	ext_info = &this_attr->c->ext_info[this_attr->address];
432 
433 	return ext_info->write(indio_dev, ext_info->private,
434 			       this_attr->c, buf, len);
435 }
436 
437 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
438 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
439 {
440 	const struct iio_enum *e = (const struct iio_enum *)priv;
441 	unsigned int i;
442 	size_t len = 0;
443 
444 	if (!e->num_items)
445 		return 0;
446 
447 	for (i = 0; i < e->num_items; ++i)
448 		len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
449 
450 	/* replace last space with a newline */
451 	buf[len - 1] = '\n';
452 
453 	return len;
454 }
455 EXPORT_SYMBOL_GPL(iio_enum_available_read);
456 
457 ssize_t iio_enum_read(struct iio_dev *indio_dev,
458 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
459 {
460 	const struct iio_enum *e = (const struct iio_enum *)priv;
461 	int i;
462 
463 	if (!e->get)
464 		return -EINVAL;
465 
466 	i = e->get(indio_dev, chan);
467 	if (i < 0)
468 		return i;
469 	else if (i >= e->num_items)
470 		return -EINVAL;
471 
472 	return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
473 }
474 EXPORT_SYMBOL_GPL(iio_enum_read);
475 
476 ssize_t iio_enum_write(struct iio_dev *indio_dev,
477 	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
478 	size_t len)
479 {
480 	const struct iio_enum *e = (const struct iio_enum *)priv;
481 	int ret;
482 
483 	if (!e->set)
484 		return -EINVAL;
485 
486 	ret = __sysfs_match_string(e->items, e->num_items, buf);
487 	if (ret < 0)
488 		return ret;
489 
490 	ret = e->set(indio_dev, chan, ret);
491 	return ret ? ret : len;
492 }
493 EXPORT_SYMBOL_GPL(iio_enum_write);
494 
495 static const struct iio_mount_matrix iio_mount_idmatrix = {
496 	.rotation = {
497 		"1", "0", "0",
498 		"0", "1", "0",
499 		"0", "0", "1"
500 	}
501 };
502 
503 static int iio_setup_mount_idmatrix(const struct device *dev,
504 				    struct iio_mount_matrix *matrix)
505 {
506 	*matrix = iio_mount_idmatrix;
507 	dev_info(dev, "mounting matrix not found: using identity...\n");
508 	return 0;
509 }
510 
511 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
512 			      const struct iio_chan_spec *chan, char *buf)
513 {
514 	const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
515 					      priv)(indio_dev, chan);
516 
517 	if (IS_ERR(mtx))
518 		return PTR_ERR(mtx);
519 
520 	if (!mtx)
521 		mtx = &iio_mount_idmatrix;
522 
523 	return snprintf(buf, PAGE_SIZE, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
524 			mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
525 			mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
526 			mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
527 }
528 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
529 
530 /**
531  * iio_read_mount_matrix() - retrieve iio device mounting matrix from
532  *                           device "mount-matrix" property
533  * @dev:	device the mounting matrix property is assigned to
534  * @propname:	device specific mounting matrix property name
535  * @matrix:	where to store retrieved matrix
536  *
537  * If device is assigned no mounting matrix property, a default 3x3 identity
538  * matrix will be filled in.
539  *
540  * Return: 0 if success, or a negative error code on failure.
541  */
542 int iio_read_mount_matrix(struct device *dev, const char *propname,
543 			  struct iio_mount_matrix *matrix)
544 {
545 	size_t len = ARRAY_SIZE(iio_mount_idmatrix.rotation);
546 	int err;
547 
548 	err = device_property_read_string_array(dev, propname,
549 						matrix->rotation, len);
550 	if (err == len)
551 		return 0;
552 
553 	if (err >= 0)
554 		/* Invalid number of matrix entries. */
555 		return -EINVAL;
556 
557 	if (err != -EINVAL)
558 		/* Invalid matrix declaration format. */
559 		return err;
560 
561 	/* Matrix was not declared at all: fallback to identity. */
562 	return iio_setup_mount_idmatrix(dev, matrix);
563 }
564 EXPORT_SYMBOL(iio_read_mount_matrix);
565 
566 static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
567 				  int size, const int *vals)
568 {
569 	unsigned long long tmp;
570 	int tmp0, tmp1;
571 	bool scale_db = false;
572 
573 	switch (type) {
574 	case IIO_VAL_INT:
575 		return snprintf(buf, len, "%d", vals[0]);
576 	case IIO_VAL_INT_PLUS_MICRO_DB:
577 		scale_db = true;
578 		/* fall through */
579 	case IIO_VAL_INT_PLUS_MICRO:
580 		if (vals[1] < 0)
581 			return snprintf(buf, len, "-%d.%06u%s", abs(vals[0]),
582 					-vals[1], scale_db ? " dB" : "");
583 		else
584 			return snprintf(buf, len, "%d.%06u%s", vals[0], vals[1],
585 					scale_db ? " dB" : "");
586 	case IIO_VAL_INT_PLUS_NANO:
587 		if (vals[1] < 0)
588 			return snprintf(buf, len, "-%d.%09u", abs(vals[0]),
589 					-vals[1]);
590 		else
591 			return snprintf(buf, len, "%d.%09u", vals[0], vals[1]);
592 	case IIO_VAL_FRACTIONAL:
593 		tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
594 		tmp1 = vals[1];
595 		tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1);
596 		return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
597 	case IIO_VAL_FRACTIONAL_LOG2:
598 		tmp = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
599 		tmp0 = (int)div_s64_rem(tmp, 1000000000LL, &tmp1);
600 		return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
601 	case IIO_VAL_INT_MULTIPLE:
602 	{
603 		int i;
604 		int l = 0;
605 
606 		for (i = 0; i < size; ++i) {
607 			l += snprintf(&buf[l], len - l, "%d ", vals[i]);
608 			if (l >= len)
609 				break;
610 		}
611 		return l;
612 	}
613 	default:
614 		return 0;
615 	}
616 }
617 
618 /**
619  * iio_format_value() - Formats a IIO value into its string representation
620  * @buf:	The buffer to which the formatted value gets written
621  *		which is assumed to be big enough (i.e. PAGE_SIZE).
622  * @type:	One of the IIO_VAL_* constants. This decides how the val
623  *		and val2 parameters are formatted.
624  * @size:	Number of IIO value entries contained in vals
625  * @vals:	Pointer to the values, exact meaning depends on the
626  *		type parameter.
627  *
628  * Return: 0 by default, a negative number on failure or the
629  *	   total number of characters written for a type that belongs
630  *	   to the IIO_VAL_* constant.
631  */
632 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
633 {
634 	ssize_t len;
635 
636 	len = __iio_format_value(buf, PAGE_SIZE, type, size, vals);
637 	if (len >= PAGE_SIZE - 1)
638 		return -EFBIG;
639 
640 	return len + sprintf(buf + len, "\n");
641 }
642 EXPORT_SYMBOL_GPL(iio_format_value);
643 
644 static ssize_t iio_read_channel_info(struct device *dev,
645 				     struct device_attribute *attr,
646 				     char *buf)
647 {
648 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
649 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
650 	int vals[INDIO_MAX_RAW_ELEMENTS];
651 	int ret;
652 	int val_len = 2;
653 
654 	if (indio_dev->info->read_raw_multi)
655 		ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
656 							INDIO_MAX_RAW_ELEMENTS,
657 							vals, &val_len,
658 							this_attr->address);
659 	else
660 		ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
661 				    &vals[0], &vals[1], this_attr->address);
662 
663 	if (ret < 0)
664 		return ret;
665 
666 	return iio_format_value(buf, ret, val_len, vals);
667 }
668 
669 static ssize_t iio_format_avail_list(char *buf, const int *vals,
670 				     int type, int length)
671 {
672 	int i;
673 	ssize_t len = 0;
674 
675 	switch (type) {
676 	case IIO_VAL_INT:
677 		for (i = 0; i < length; i++) {
678 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
679 						  type, 1, &vals[i]);
680 			if (len >= PAGE_SIZE)
681 				return -EFBIG;
682 			if (i < length - 1)
683 				len += snprintf(buf + len, PAGE_SIZE - len,
684 						" ");
685 			else
686 				len += snprintf(buf + len, PAGE_SIZE - len,
687 						"\n");
688 			if (len >= PAGE_SIZE)
689 				return -EFBIG;
690 		}
691 		break;
692 	default:
693 		for (i = 0; i < length / 2; i++) {
694 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
695 						  type, 2, &vals[i * 2]);
696 			if (len >= PAGE_SIZE)
697 				return -EFBIG;
698 			if (i < length / 2 - 1)
699 				len += snprintf(buf + len, PAGE_SIZE - len,
700 						" ");
701 			else
702 				len += snprintf(buf + len, PAGE_SIZE - len,
703 						"\n");
704 			if (len >= PAGE_SIZE)
705 				return -EFBIG;
706 		}
707 	}
708 
709 	return len;
710 }
711 
712 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
713 {
714 	int i;
715 	ssize_t len;
716 
717 	len = snprintf(buf, PAGE_SIZE, "[");
718 	switch (type) {
719 	case IIO_VAL_INT:
720 		for (i = 0; i < 3; i++) {
721 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
722 						  type, 1, &vals[i]);
723 			if (len >= PAGE_SIZE)
724 				return -EFBIG;
725 			if (i < 2)
726 				len += snprintf(buf + len, PAGE_SIZE - len,
727 						" ");
728 			else
729 				len += snprintf(buf + len, PAGE_SIZE - len,
730 						"]\n");
731 			if (len >= PAGE_SIZE)
732 				return -EFBIG;
733 		}
734 		break;
735 	default:
736 		for (i = 0; i < 3; i++) {
737 			len += __iio_format_value(buf + len, PAGE_SIZE - len,
738 						  type, 2, &vals[i * 2]);
739 			if (len >= PAGE_SIZE)
740 				return -EFBIG;
741 			if (i < 2)
742 				len += snprintf(buf + len, PAGE_SIZE - len,
743 						" ");
744 			else
745 				len += snprintf(buf + len, PAGE_SIZE - len,
746 						"]\n");
747 			if (len >= PAGE_SIZE)
748 				return -EFBIG;
749 		}
750 	}
751 
752 	return len;
753 }
754 
755 static ssize_t iio_read_channel_info_avail(struct device *dev,
756 					   struct device_attribute *attr,
757 					   char *buf)
758 {
759 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
760 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
761 	const int *vals;
762 	int ret;
763 	int length;
764 	int type;
765 
766 	ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
767 					  &vals, &type, &length,
768 					  this_attr->address);
769 
770 	if (ret < 0)
771 		return ret;
772 	switch (ret) {
773 	case IIO_AVAIL_LIST:
774 		return iio_format_avail_list(buf, vals, type, length);
775 	case IIO_AVAIL_RANGE:
776 		return iio_format_avail_range(buf, vals, type);
777 	default:
778 		return -EINVAL;
779 	}
780 }
781 
782 /**
783  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
784  * @str: The string to parse
785  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
786  * @integer: The integer part of the number
787  * @fract: The fractional part of the number
788  *
789  * Returns 0 on success, or a negative error code if the string could not be
790  * parsed.
791  */
792 int iio_str_to_fixpoint(const char *str, int fract_mult,
793 	int *integer, int *fract)
794 {
795 	int i = 0, f = 0;
796 	bool integer_part = true, negative = false;
797 
798 	if (fract_mult == 0) {
799 		*fract = 0;
800 
801 		return kstrtoint(str, 0, integer);
802 	}
803 
804 	if (str[0] == '-') {
805 		negative = true;
806 		str++;
807 	} else if (str[0] == '+') {
808 		str++;
809 	}
810 
811 	while (*str) {
812 		if ('0' <= *str && *str <= '9') {
813 			if (integer_part) {
814 				i = i * 10 + *str - '0';
815 			} else {
816 				f += fract_mult * (*str - '0');
817 				fract_mult /= 10;
818 			}
819 		} else if (*str == '\n') {
820 			if (*(str + 1) == '\0')
821 				break;
822 			else
823 				return -EINVAL;
824 		} else if (*str == '.' && integer_part) {
825 			integer_part = false;
826 		} else {
827 			return -EINVAL;
828 		}
829 		str++;
830 	}
831 
832 	if (negative) {
833 		if (i)
834 			i = -i;
835 		else
836 			f = -f;
837 	}
838 
839 	*integer = i;
840 	*fract = f;
841 
842 	return 0;
843 }
844 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
845 
846 static ssize_t iio_write_channel_info(struct device *dev,
847 				      struct device_attribute *attr,
848 				      const char *buf,
849 				      size_t len)
850 {
851 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
852 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
853 	int ret, fract_mult = 100000;
854 	int integer, fract;
855 
856 	/* Assumes decimal - precision based on number of digits */
857 	if (!indio_dev->info->write_raw)
858 		return -EINVAL;
859 
860 	if (indio_dev->info->write_raw_get_fmt)
861 		switch (indio_dev->info->write_raw_get_fmt(indio_dev,
862 			this_attr->c, this_attr->address)) {
863 		case IIO_VAL_INT:
864 			fract_mult = 0;
865 			break;
866 		case IIO_VAL_INT_PLUS_MICRO:
867 			fract_mult = 100000;
868 			break;
869 		case IIO_VAL_INT_PLUS_NANO:
870 			fract_mult = 100000000;
871 			break;
872 		default:
873 			return -EINVAL;
874 		}
875 
876 	ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
877 	if (ret)
878 		return ret;
879 
880 	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
881 					 integer, fract, this_attr->address);
882 	if (ret)
883 		return ret;
884 
885 	return len;
886 }
887 
888 static
889 int __iio_device_attr_init(struct device_attribute *dev_attr,
890 			   const char *postfix,
891 			   struct iio_chan_spec const *chan,
892 			   ssize_t (*readfunc)(struct device *dev,
893 					       struct device_attribute *attr,
894 					       char *buf),
895 			   ssize_t (*writefunc)(struct device *dev,
896 						struct device_attribute *attr,
897 						const char *buf,
898 						size_t len),
899 			   enum iio_shared_by shared_by)
900 {
901 	int ret = 0;
902 	char *name = NULL;
903 	char *full_postfix;
904 	sysfs_attr_init(&dev_attr->attr);
905 
906 	/* Build up postfix of <extend_name>_<modifier>_postfix */
907 	if (chan->modified && (shared_by == IIO_SEPARATE)) {
908 		if (chan->extend_name)
909 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
910 						 iio_modifier_names[chan
911 								    ->channel2],
912 						 chan->extend_name,
913 						 postfix);
914 		else
915 			full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
916 						 iio_modifier_names[chan
917 								    ->channel2],
918 						 postfix);
919 	} else {
920 		if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
921 			full_postfix = kstrdup(postfix, GFP_KERNEL);
922 		else
923 			full_postfix = kasprintf(GFP_KERNEL,
924 						 "%s_%s",
925 						 chan->extend_name,
926 						 postfix);
927 	}
928 	if (full_postfix == NULL)
929 		return -ENOMEM;
930 
931 	if (chan->differential) { /* Differential can not have modifier */
932 		switch (shared_by) {
933 		case IIO_SHARED_BY_ALL:
934 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
935 			break;
936 		case IIO_SHARED_BY_DIR:
937 			name = kasprintf(GFP_KERNEL, "%s_%s",
938 						iio_direction[chan->output],
939 						full_postfix);
940 			break;
941 		case IIO_SHARED_BY_TYPE:
942 			name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
943 					    iio_direction[chan->output],
944 					    iio_chan_type_name_spec[chan->type],
945 					    iio_chan_type_name_spec[chan->type],
946 					    full_postfix);
947 			break;
948 		case IIO_SEPARATE:
949 			if (!chan->indexed) {
950 				WARN(1, "Differential channels must be indexed\n");
951 				ret = -EINVAL;
952 				goto error_free_full_postfix;
953 			}
954 			name = kasprintf(GFP_KERNEL,
955 					    "%s_%s%d-%s%d_%s",
956 					    iio_direction[chan->output],
957 					    iio_chan_type_name_spec[chan->type],
958 					    chan->channel,
959 					    iio_chan_type_name_spec[chan->type],
960 					    chan->channel2,
961 					    full_postfix);
962 			break;
963 		}
964 	} else { /* Single ended */
965 		switch (shared_by) {
966 		case IIO_SHARED_BY_ALL:
967 			name = kasprintf(GFP_KERNEL, "%s", full_postfix);
968 			break;
969 		case IIO_SHARED_BY_DIR:
970 			name = kasprintf(GFP_KERNEL, "%s_%s",
971 						iio_direction[chan->output],
972 						full_postfix);
973 			break;
974 		case IIO_SHARED_BY_TYPE:
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 		case IIO_SEPARATE:
982 			if (chan->indexed)
983 				name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
984 						    iio_direction[chan->output],
985 						    iio_chan_type_name_spec[chan->type],
986 						    chan->channel,
987 						    full_postfix);
988 			else
989 				name = kasprintf(GFP_KERNEL, "%s_%s_%s",
990 						    iio_direction[chan->output],
991 						    iio_chan_type_name_spec[chan->type],
992 						    full_postfix);
993 			break;
994 		}
995 	}
996 	if (name == NULL) {
997 		ret = -ENOMEM;
998 		goto error_free_full_postfix;
999 	}
1000 	dev_attr->attr.name = name;
1001 
1002 	if (readfunc) {
1003 		dev_attr->attr.mode |= S_IRUGO;
1004 		dev_attr->show = readfunc;
1005 	}
1006 
1007 	if (writefunc) {
1008 		dev_attr->attr.mode |= S_IWUSR;
1009 		dev_attr->store = writefunc;
1010 	}
1011 
1012 error_free_full_postfix:
1013 	kfree(full_postfix);
1014 
1015 	return ret;
1016 }
1017 
1018 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1019 {
1020 	kfree(dev_attr->attr.name);
1021 }
1022 
1023 int __iio_add_chan_devattr(const char *postfix,
1024 			   struct iio_chan_spec const *chan,
1025 			   ssize_t (*readfunc)(struct device *dev,
1026 					       struct device_attribute *attr,
1027 					       char *buf),
1028 			   ssize_t (*writefunc)(struct device *dev,
1029 						struct device_attribute *attr,
1030 						const char *buf,
1031 						size_t len),
1032 			   u64 mask,
1033 			   enum iio_shared_by shared_by,
1034 			   struct device *dev,
1035 			   struct list_head *attr_list)
1036 {
1037 	int ret;
1038 	struct iio_dev_attr *iio_attr, *t;
1039 
1040 	iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1041 	if (iio_attr == NULL)
1042 		return -ENOMEM;
1043 	ret = __iio_device_attr_init(&iio_attr->dev_attr,
1044 				     postfix, chan,
1045 				     readfunc, writefunc, shared_by);
1046 	if (ret)
1047 		goto error_iio_dev_attr_free;
1048 	iio_attr->c = chan;
1049 	iio_attr->address = mask;
1050 	list_for_each_entry(t, attr_list, l)
1051 		if (strcmp(t->dev_attr.attr.name,
1052 			   iio_attr->dev_attr.attr.name) == 0) {
1053 			if (shared_by == IIO_SEPARATE)
1054 				dev_err(dev, "tried to double register : %s\n",
1055 					t->dev_attr.attr.name);
1056 			ret = -EBUSY;
1057 			goto error_device_attr_deinit;
1058 		}
1059 	list_add(&iio_attr->l, attr_list);
1060 
1061 	return 0;
1062 
1063 error_device_attr_deinit:
1064 	__iio_device_attr_deinit(&iio_attr->dev_attr);
1065 error_iio_dev_attr_free:
1066 	kfree(iio_attr);
1067 	return ret;
1068 }
1069 
1070 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1071 					 struct iio_chan_spec const *chan,
1072 					 enum iio_shared_by shared_by,
1073 					 const long *infomask)
1074 {
1075 	int i, ret, attrcount = 0;
1076 
1077 	for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1078 		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1079 			return -EINVAL;
1080 		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1081 					     chan,
1082 					     &iio_read_channel_info,
1083 					     &iio_write_channel_info,
1084 					     i,
1085 					     shared_by,
1086 					     &indio_dev->dev,
1087 					     &indio_dev->channel_attr_list);
1088 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1089 			continue;
1090 		else if (ret < 0)
1091 			return ret;
1092 		attrcount++;
1093 	}
1094 
1095 	return attrcount;
1096 }
1097 
1098 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1099 					       struct iio_chan_spec const *chan,
1100 					       enum iio_shared_by shared_by,
1101 					       const long *infomask)
1102 {
1103 	int i, ret, attrcount = 0;
1104 	char *avail_postfix;
1105 
1106 	for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1107 		avail_postfix = kasprintf(GFP_KERNEL,
1108 					  "%s_available",
1109 					  iio_chan_info_postfix[i]);
1110 		if (!avail_postfix)
1111 			return -ENOMEM;
1112 
1113 		ret = __iio_add_chan_devattr(avail_postfix,
1114 					     chan,
1115 					     &iio_read_channel_info_avail,
1116 					     NULL,
1117 					     i,
1118 					     shared_by,
1119 					     &indio_dev->dev,
1120 					     &indio_dev->channel_attr_list);
1121 		kfree(avail_postfix);
1122 		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1123 			continue;
1124 		else if (ret < 0)
1125 			return ret;
1126 		attrcount++;
1127 	}
1128 
1129 	return attrcount;
1130 }
1131 
1132 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1133 					struct iio_chan_spec const *chan)
1134 {
1135 	int ret, attrcount = 0;
1136 	const struct iio_chan_spec_ext_info *ext_info;
1137 
1138 	if (chan->channel < 0)
1139 		return 0;
1140 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1141 					    IIO_SEPARATE,
1142 					    &chan->info_mask_separate);
1143 	if (ret < 0)
1144 		return ret;
1145 	attrcount += ret;
1146 
1147 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1148 						  IIO_SEPARATE,
1149 						  &chan->
1150 						  info_mask_separate_available);
1151 	if (ret < 0)
1152 		return ret;
1153 	attrcount += ret;
1154 
1155 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1156 					    IIO_SHARED_BY_TYPE,
1157 					    &chan->info_mask_shared_by_type);
1158 	if (ret < 0)
1159 		return ret;
1160 	attrcount += ret;
1161 
1162 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1163 						  IIO_SHARED_BY_TYPE,
1164 						  &chan->
1165 						  info_mask_shared_by_type_available);
1166 	if (ret < 0)
1167 		return ret;
1168 	attrcount += ret;
1169 
1170 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1171 					    IIO_SHARED_BY_DIR,
1172 					    &chan->info_mask_shared_by_dir);
1173 	if (ret < 0)
1174 		return ret;
1175 	attrcount += ret;
1176 
1177 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1178 						  IIO_SHARED_BY_DIR,
1179 						  &chan->info_mask_shared_by_dir_available);
1180 	if (ret < 0)
1181 		return ret;
1182 	attrcount += ret;
1183 
1184 	ret = iio_device_add_info_mask_type(indio_dev, chan,
1185 					    IIO_SHARED_BY_ALL,
1186 					    &chan->info_mask_shared_by_all);
1187 	if (ret < 0)
1188 		return ret;
1189 	attrcount += ret;
1190 
1191 	ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1192 						  IIO_SHARED_BY_ALL,
1193 						  &chan->info_mask_shared_by_all_available);
1194 	if (ret < 0)
1195 		return ret;
1196 	attrcount += ret;
1197 
1198 	if (chan->ext_info) {
1199 		unsigned int i = 0;
1200 		for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1201 			ret = __iio_add_chan_devattr(ext_info->name,
1202 					chan,
1203 					ext_info->read ?
1204 					    &iio_read_channel_ext_info : NULL,
1205 					ext_info->write ?
1206 					    &iio_write_channel_ext_info : NULL,
1207 					i,
1208 					ext_info->shared,
1209 					&indio_dev->dev,
1210 					&indio_dev->channel_attr_list);
1211 			i++;
1212 			if (ret == -EBUSY && ext_info->shared)
1213 				continue;
1214 
1215 			if (ret)
1216 				return ret;
1217 
1218 			attrcount++;
1219 		}
1220 	}
1221 
1222 	return attrcount;
1223 }
1224 
1225 /**
1226  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1227  * @attr_list: List of IIO device attributes
1228  *
1229  * This function frees the memory allocated for each of the IIO device
1230  * attributes in the list.
1231  */
1232 void iio_free_chan_devattr_list(struct list_head *attr_list)
1233 {
1234 	struct iio_dev_attr *p, *n;
1235 
1236 	list_for_each_entry_safe(p, n, attr_list, l) {
1237 		kfree(p->dev_attr.attr.name);
1238 		list_del(&p->l);
1239 		kfree(p);
1240 	}
1241 }
1242 
1243 static ssize_t iio_show_dev_name(struct device *dev,
1244 				 struct device_attribute *attr,
1245 				 char *buf)
1246 {
1247 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1248 	return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
1249 }
1250 
1251 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
1252 
1253 static ssize_t iio_show_timestamp_clock(struct device *dev,
1254 					struct device_attribute *attr,
1255 					char *buf)
1256 {
1257 	const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1258 	const clockid_t clk = iio_device_get_clock(indio_dev);
1259 	const char *name;
1260 	ssize_t sz;
1261 
1262 	switch (clk) {
1263 	case CLOCK_REALTIME:
1264 		name = "realtime\n";
1265 		sz = sizeof("realtime\n");
1266 		break;
1267 	case CLOCK_MONOTONIC:
1268 		name = "monotonic\n";
1269 		sz = sizeof("monotonic\n");
1270 		break;
1271 	case CLOCK_MONOTONIC_RAW:
1272 		name = "monotonic_raw\n";
1273 		sz = sizeof("monotonic_raw\n");
1274 		break;
1275 	case CLOCK_REALTIME_COARSE:
1276 		name = "realtime_coarse\n";
1277 		sz = sizeof("realtime_coarse\n");
1278 		break;
1279 	case CLOCK_MONOTONIC_COARSE:
1280 		name = "monotonic_coarse\n";
1281 		sz = sizeof("monotonic_coarse\n");
1282 		break;
1283 	case CLOCK_BOOTTIME:
1284 		name = "boottime\n";
1285 		sz = sizeof("boottime\n");
1286 		break;
1287 	case CLOCK_TAI:
1288 		name = "tai\n";
1289 		sz = sizeof("tai\n");
1290 		break;
1291 	default:
1292 		BUG();
1293 	}
1294 
1295 	memcpy(buf, name, sz);
1296 	return sz;
1297 }
1298 
1299 static ssize_t iio_store_timestamp_clock(struct device *dev,
1300 					 struct device_attribute *attr,
1301 					 const char *buf, size_t len)
1302 {
1303 	clockid_t clk;
1304 	int ret;
1305 
1306 	if (sysfs_streq(buf, "realtime"))
1307 		clk = CLOCK_REALTIME;
1308 	else if (sysfs_streq(buf, "monotonic"))
1309 		clk = CLOCK_MONOTONIC;
1310 	else if (sysfs_streq(buf, "monotonic_raw"))
1311 		clk = CLOCK_MONOTONIC_RAW;
1312 	else if (sysfs_streq(buf, "realtime_coarse"))
1313 		clk = CLOCK_REALTIME_COARSE;
1314 	else if (sysfs_streq(buf, "monotonic_coarse"))
1315 		clk = CLOCK_MONOTONIC_COARSE;
1316 	else if (sysfs_streq(buf, "boottime"))
1317 		clk = CLOCK_BOOTTIME;
1318 	else if (sysfs_streq(buf, "tai"))
1319 		clk = CLOCK_TAI;
1320 	else
1321 		return -EINVAL;
1322 
1323 	ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1324 	if (ret)
1325 		return ret;
1326 
1327 	return len;
1328 }
1329 
1330 static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1331 		   iio_show_timestamp_clock, iio_store_timestamp_clock);
1332 
1333 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1334 {
1335 	int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1336 	struct iio_dev_attr *p;
1337 	struct attribute **attr, *clk = NULL;
1338 
1339 	/* First count elements in any existing group */
1340 	if (indio_dev->info->attrs) {
1341 		attr = indio_dev->info->attrs->attrs;
1342 		while (*attr++ != NULL)
1343 			attrcount_orig++;
1344 	}
1345 	attrcount = attrcount_orig;
1346 	/*
1347 	 * New channel registration method - relies on the fact a group does
1348 	 * not need to be initialized if its name is NULL.
1349 	 */
1350 	if (indio_dev->channels)
1351 		for (i = 0; i < indio_dev->num_channels; i++) {
1352 			const struct iio_chan_spec *chan =
1353 				&indio_dev->channels[i];
1354 
1355 			if (chan->type == IIO_TIMESTAMP)
1356 				clk = &dev_attr_current_timestamp_clock.attr;
1357 
1358 			ret = iio_device_add_channel_sysfs(indio_dev, chan);
1359 			if (ret < 0)
1360 				goto error_clear_attrs;
1361 			attrcount += ret;
1362 		}
1363 
1364 	if (indio_dev->event_interface)
1365 		clk = &dev_attr_current_timestamp_clock.attr;
1366 
1367 	if (indio_dev->name)
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 (clk)
1392 		indio_dev->chan_attr_group.attrs[attrn++] = clk;
1393 
1394 	indio_dev->groups[indio_dev->groupcounter++] =
1395 		&indio_dev->chan_attr_group;
1396 
1397 	return 0;
1398 
1399 error_clear_attrs:
1400 	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1401 
1402 	return ret;
1403 }
1404 
1405 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1406 {
1407 
1408 	iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1409 	kfree(indio_dev->chan_attr_group.attrs);
1410 	indio_dev->chan_attr_group.attrs = NULL;
1411 }
1412 
1413 static void iio_dev_release(struct device *device)
1414 {
1415 	struct iio_dev *indio_dev = dev_to_iio_dev(device);
1416 	if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1417 		iio_device_unregister_trigger_consumer(indio_dev);
1418 	iio_device_unregister_eventset(indio_dev);
1419 	iio_device_unregister_sysfs(indio_dev);
1420 
1421 	iio_buffer_put(indio_dev->buffer);
1422 
1423 	ida_simple_remove(&iio_ida, indio_dev->id);
1424 	kfree(indio_dev);
1425 }
1426 
1427 struct device_type iio_device_type = {
1428 	.name = "iio_device",
1429 	.release = iio_dev_release,
1430 };
1431 
1432 /**
1433  * iio_device_alloc() - allocate an iio_dev from a driver
1434  * @sizeof_priv:	Space to allocate for private structure.
1435  **/
1436 struct iio_dev *iio_device_alloc(int sizeof_priv)
1437 {
1438 	struct iio_dev *dev;
1439 	size_t alloc_size;
1440 
1441 	alloc_size = sizeof(struct iio_dev);
1442 	if (sizeof_priv) {
1443 		alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1444 		alloc_size += sizeof_priv;
1445 	}
1446 	/* ensure 32-byte alignment of whole construct ? */
1447 	alloc_size += IIO_ALIGN - 1;
1448 
1449 	dev = kzalloc(alloc_size, GFP_KERNEL);
1450 
1451 	if (dev) {
1452 		dev->dev.groups = dev->groups;
1453 		dev->dev.type = &iio_device_type;
1454 		dev->dev.bus = &iio_bus_type;
1455 		device_initialize(&dev->dev);
1456 		dev_set_drvdata(&dev->dev, (void *)dev);
1457 		mutex_init(&dev->mlock);
1458 		mutex_init(&dev->info_exist_lock);
1459 		INIT_LIST_HEAD(&dev->channel_attr_list);
1460 
1461 		dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1462 		if (dev->id < 0) {
1463 			/* cannot use a dev_err as the name isn't available */
1464 			pr_err("failed to get device id\n");
1465 			kfree(dev);
1466 			return NULL;
1467 		}
1468 		dev_set_name(&dev->dev, "iio:device%d", dev->id);
1469 		INIT_LIST_HEAD(&dev->buffer_list);
1470 	}
1471 
1472 	return dev;
1473 }
1474 EXPORT_SYMBOL(iio_device_alloc);
1475 
1476 /**
1477  * iio_device_free() - free an iio_dev from a driver
1478  * @dev:		the iio_dev associated with the device
1479  **/
1480 void iio_device_free(struct iio_dev *dev)
1481 {
1482 	if (dev)
1483 		put_device(&dev->dev);
1484 }
1485 EXPORT_SYMBOL(iio_device_free);
1486 
1487 static void devm_iio_device_release(struct device *dev, void *res)
1488 {
1489 	iio_device_free(*(struct iio_dev **)res);
1490 }
1491 
1492 int devm_iio_device_match(struct device *dev, void *res, void *data)
1493 {
1494 	struct iio_dev **r = res;
1495 	if (!r || !*r) {
1496 		WARN_ON(!r || !*r);
1497 		return 0;
1498 	}
1499 	return *r == data;
1500 }
1501 EXPORT_SYMBOL_GPL(devm_iio_device_match);
1502 
1503 /**
1504  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1505  * @dev:		Device to allocate iio_dev for
1506  * @sizeof_priv:	Space to allocate for private structure.
1507  *
1508  * Managed iio_device_alloc. iio_dev allocated with this function is
1509  * automatically freed on driver detach.
1510  *
1511  * If an iio_dev allocated with this function needs to be freed separately,
1512  * devm_iio_device_free() must be used.
1513  *
1514  * RETURNS:
1515  * Pointer to allocated iio_dev on success, NULL on failure.
1516  */
1517 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1518 {
1519 	struct iio_dev **ptr, *iio_dev;
1520 
1521 	ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1522 			   GFP_KERNEL);
1523 	if (!ptr)
1524 		return NULL;
1525 
1526 	iio_dev = iio_device_alloc(sizeof_priv);
1527 	if (iio_dev) {
1528 		*ptr = iio_dev;
1529 		devres_add(dev, ptr);
1530 	} else {
1531 		devres_free(ptr);
1532 	}
1533 
1534 	return iio_dev;
1535 }
1536 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1537 
1538 /**
1539  * devm_iio_device_free - Resource-managed iio_device_free()
1540  * @dev:		Device this iio_dev belongs to
1541  * @iio_dev:		the iio_dev associated with the device
1542  *
1543  * Free iio_dev allocated with devm_iio_device_alloc().
1544  */
1545 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1546 {
1547 	int rc;
1548 
1549 	rc = devres_release(dev, devm_iio_device_release,
1550 			    devm_iio_device_match, iio_dev);
1551 	WARN_ON(rc);
1552 }
1553 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1554 
1555 /**
1556  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1557  * @inode:	Inode structure for identifying the device in the file system
1558  * @filp:	File structure for iio device used to keep and later access
1559  *		private data
1560  *
1561  * Return: 0 on success or -EBUSY if the device is already opened
1562  **/
1563 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1564 {
1565 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1566 						struct iio_dev, chrdev);
1567 
1568 	if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1569 		return -EBUSY;
1570 
1571 	iio_device_get(indio_dev);
1572 
1573 	filp->private_data = indio_dev;
1574 
1575 	return 0;
1576 }
1577 
1578 /**
1579  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1580  * @inode:	Inode structure pointer for the char device
1581  * @filp:	File structure pointer for the char device
1582  *
1583  * Return: 0 for successful release
1584  */
1585 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1586 {
1587 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
1588 						struct iio_dev, chrdev);
1589 	clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1590 	iio_device_put(indio_dev);
1591 
1592 	return 0;
1593 }
1594 
1595 /* Somewhat of a cross file organization violation - ioctls here are actually
1596  * event related */
1597 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1598 {
1599 	struct iio_dev *indio_dev = filp->private_data;
1600 	int __user *ip = (int __user *)arg;
1601 	int fd;
1602 
1603 	if (!indio_dev->info)
1604 		return -ENODEV;
1605 
1606 	if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1607 		fd = iio_event_getfd(indio_dev);
1608 		if (fd < 0)
1609 			return fd;
1610 		if (copy_to_user(ip, &fd, sizeof(fd)))
1611 			return -EFAULT;
1612 		return 0;
1613 	}
1614 	return -EINVAL;
1615 }
1616 
1617 static const struct file_operations iio_buffer_fileops = {
1618 	.read = iio_buffer_read_first_n_outer_addr,
1619 	.release = iio_chrdev_release,
1620 	.open = iio_chrdev_open,
1621 	.poll = iio_buffer_poll_addr,
1622 	.owner = THIS_MODULE,
1623 	.llseek = noop_llseek,
1624 	.unlocked_ioctl = iio_ioctl,
1625 	.compat_ioctl = iio_ioctl,
1626 };
1627 
1628 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1629 {
1630 	int i, j;
1631 	const struct iio_chan_spec *channels = indio_dev->channels;
1632 
1633 	if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1634 		return 0;
1635 
1636 	for (i = 0; i < indio_dev->num_channels - 1; i++) {
1637 		if (channels[i].scan_index < 0)
1638 			continue;
1639 		for (j = i + 1; j < indio_dev->num_channels; j++)
1640 			if (channels[i].scan_index == channels[j].scan_index) {
1641 				dev_err(&indio_dev->dev,
1642 					"Duplicate scan index %d\n",
1643 					channels[i].scan_index);
1644 				return -EINVAL;
1645 			}
1646 	}
1647 
1648 	return 0;
1649 }
1650 
1651 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1652 
1653 int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1654 {
1655 	int ret;
1656 
1657 	indio_dev->driver_module = this_mod;
1658 	/* If the calling driver did not initialize of_node, do it here */
1659 	if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1660 		indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1661 
1662 	ret = iio_check_unique_scan_index(indio_dev);
1663 	if (ret < 0)
1664 		return ret;
1665 
1666 	if (!indio_dev->info)
1667 		return -EINVAL;
1668 
1669 	/* configure elements for the chrdev */
1670 	indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1671 
1672 	ret = iio_device_register_debugfs(indio_dev);
1673 	if (ret) {
1674 		dev_err(indio_dev->dev.parent,
1675 			"Failed to register debugfs interfaces\n");
1676 		return ret;
1677 	}
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