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[deliverable/linux.git] / drivers / iio / industrialio-core.c
1 /* The industrial I/O core
2 *
3 * Copyright (c) 2008 Jonathan Cameron
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 as published by
7 * the Free Software Foundation.
8 *
9 * Based on elements of hwmon and input subsystems.
10 */
11
12 #define pr_fmt(fmt) "iio-core: " fmt
13
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/idr.h>
17 #include <linux/kdev_t.h>
18 #include <linux/err.h>
19 #include <linux/device.h>
20 #include <linux/fs.h>
21 #include <linux/poll.h>
22 #include <linux/sched.h>
23 #include <linux/wait.h>
24 #include <linux/cdev.h>
25 #include <linux/slab.h>
26 #include <linux/anon_inodes.h>
27 #include <linux/debugfs.h>
28 #include <linux/mutex.h>
29 #include <linux/iio/iio.h>
30 #include "iio_core.h"
31 #include "iio_core_trigger.h"
32 #include <linux/iio/sysfs.h>
33 #include <linux/iio/events.h>
34 #include <linux/iio/buffer.h>
35
36 /* IDA to assign each registered device a unique id */
37 static DEFINE_IDA(iio_ida);
38
39 static dev_t iio_devt;
40
41 #define IIO_DEV_MAX 256
42 struct bus_type iio_bus_type = {
43 .name = "iio",
44 };
45 EXPORT_SYMBOL(iio_bus_type);
46
47 static struct dentry *iio_debugfs_dentry;
48
49 static const char * const iio_direction[] = {
50 [0] = "in",
51 [1] = "out",
52 };
53
54 static const char * const iio_chan_type_name_spec[] = {
55 [IIO_VOLTAGE] = "voltage",
56 [IIO_CURRENT] = "current",
57 [IIO_POWER] = "power",
58 [IIO_ACCEL] = "accel",
59 [IIO_ANGL_VEL] = "anglvel",
60 [IIO_MAGN] = "magn",
61 [IIO_LIGHT] = "illuminance",
62 [IIO_INTENSITY] = "intensity",
63 [IIO_PROXIMITY] = "proximity",
64 [IIO_TEMP] = "temp",
65 [IIO_INCLI] = "incli",
66 [IIO_ROT] = "rot",
67 [IIO_ANGL] = "angl",
68 [IIO_TIMESTAMP] = "timestamp",
69 [IIO_CAPACITANCE] = "capacitance",
70 [IIO_ALTVOLTAGE] = "altvoltage",
71 [IIO_CCT] = "cct",
72 [IIO_PRESSURE] = "pressure",
73 [IIO_HUMIDITYRELATIVE] = "humidityrelative",
74 [IIO_ACTIVITY] = "activity",
75 [IIO_STEPS] = "steps",
76 [IIO_ENERGY] = "energy",
77 [IIO_DISTANCE] = "distance",
78 [IIO_VELOCITY] = "velocity",
79 [IIO_CONCENTRATION] = "concentration",
80 [IIO_RESISTANCE] = "resistance",
81 [IIO_PH] = "ph",
82 };
83
84 static const char * const iio_modifier_names[] = {
85 [IIO_MOD_X] = "x",
86 [IIO_MOD_Y] = "y",
87 [IIO_MOD_Z] = "z",
88 [IIO_MOD_X_AND_Y] = "x&y",
89 [IIO_MOD_X_AND_Z] = "x&z",
90 [IIO_MOD_Y_AND_Z] = "y&z",
91 [IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
92 [IIO_MOD_X_OR_Y] = "x|y",
93 [IIO_MOD_X_OR_Z] = "x|z",
94 [IIO_MOD_Y_OR_Z] = "y|z",
95 [IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
96 [IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
97 [IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
98 [IIO_MOD_LIGHT_BOTH] = "both",
99 [IIO_MOD_LIGHT_IR] = "ir",
100 [IIO_MOD_LIGHT_CLEAR] = "clear",
101 [IIO_MOD_LIGHT_RED] = "red",
102 [IIO_MOD_LIGHT_GREEN] = "green",
103 [IIO_MOD_LIGHT_BLUE] = "blue",
104 [IIO_MOD_QUATERNION] = "quaternion",
105 [IIO_MOD_TEMP_AMBIENT] = "ambient",
106 [IIO_MOD_TEMP_OBJECT] = "object",
107 [IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
108 [IIO_MOD_NORTH_TRUE] = "from_north_true",
109 [IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
110 [IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
111 [IIO_MOD_RUNNING] = "running",
112 [IIO_MOD_JOGGING] = "jogging",
113 [IIO_MOD_WALKING] = "walking",
114 [IIO_MOD_STILL] = "still",
115 [IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
116 [IIO_MOD_I] = "i",
117 [IIO_MOD_Q] = "q",
118 [IIO_MOD_CO2] = "co2",
119 [IIO_MOD_VOC] = "voc",
120 };
121
122 /* relies on pairs of these shared then separate */
123 static const char * const iio_chan_info_postfix[] = {
124 [IIO_CHAN_INFO_RAW] = "raw",
125 [IIO_CHAN_INFO_PROCESSED] = "input",
126 [IIO_CHAN_INFO_SCALE] = "scale",
127 [IIO_CHAN_INFO_OFFSET] = "offset",
128 [IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
129 [IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
130 [IIO_CHAN_INFO_PEAK] = "peak_raw",
131 [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
132 [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
133 [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
134 [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
135 = "filter_low_pass_3db_frequency",
136 [IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
137 = "filter_high_pass_3db_frequency",
138 [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
139 [IIO_CHAN_INFO_FREQUENCY] = "frequency",
140 [IIO_CHAN_INFO_PHASE] = "phase",
141 [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
142 [IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
143 [IIO_CHAN_INFO_INT_TIME] = "integration_time",
144 [IIO_CHAN_INFO_ENABLE] = "en",
145 [IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
146 [IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
147 [IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
148 [IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
149 [IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
150 [IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
151 };
152
153 /**
154 * iio_find_channel_from_si() - get channel from its scan index
155 * @indio_dev: device
156 * @si: scan index to match
157 */
158 const struct iio_chan_spec
159 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
160 {
161 int i;
162
163 for (i = 0; i < indio_dev->num_channels; i++)
164 if (indio_dev->channels[i].scan_index == si)
165 return &indio_dev->channels[i];
166 return NULL;
167 }
168
169 /* This turns up an awful lot */
170 ssize_t iio_read_const_attr(struct device *dev,
171 struct device_attribute *attr,
172 char *buf)
173 {
174 return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
175 }
176 EXPORT_SYMBOL(iio_read_const_attr);
177
178 static int __init iio_init(void)
179 {
180 int ret;
181
182 /* Register sysfs bus */
183 ret = bus_register(&iio_bus_type);
184 if (ret < 0) {
185 pr_err("could not register bus type\n");
186 goto error_nothing;
187 }
188
189 ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
190 if (ret < 0) {
191 pr_err("failed to allocate char dev region\n");
192 goto error_unregister_bus_type;
193 }
194
195 iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
196
197 return 0;
198
199 error_unregister_bus_type:
200 bus_unregister(&iio_bus_type);
201 error_nothing:
202 return ret;
203 }
204
205 static void __exit iio_exit(void)
206 {
207 if (iio_devt)
208 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
209 bus_unregister(&iio_bus_type);
210 debugfs_remove(iio_debugfs_dentry);
211 }
212
213 #if defined(CONFIG_DEBUG_FS)
214 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
215 size_t count, loff_t *ppos)
216 {
217 struct iio_dev *indio_dev = file->private_data;
218 char buf[20];
219 unsigned val = 0;
220 ssize_t len;
221 int ret;
222
223 ret = indio_dev->info->debugfs_reg_access(indio_dev,
224 indio_dev->cached_reg_addr,
225 0, &val);
226 if (ret)
227 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
228
229 len = snprintf(buf, sizeof(buf), "0x%X\n", val);
230
231 return simple_read_from_buffer(userbuf, count, ppos, buf, len);
232 }
233
234 static ssize_t iio_debugfs_write_reg(struct file *file,
235 const char __user *userbuf, size_t count, loff_t *ppos)
236 {
237 struct iio_dev *indio_dev = file->private_data;
238 unsigned reg, val;
239 char buf[80];
240 int ret;
241
242 count = min_t(size_t, count, (sizeof(buf)-1));
243 if (copy_from_user(buf, userbuf, count))
244 return -EFAULT;
245
246 buf[count] = 0;
247
248 ret = sscanf(buf, "%i %i", &reg, &val);
249
250 switch (ret) {
251 case 1:
252 indio_dev->cached_reg_addr = reg;
253 break;
254 case 2:
255 indio_dev->cached_reg_addr = reg;
256 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
257 val, NULL);
258 if (ret) {
259 dev_err(indio_dev->dev.parent, "%s: write failed\n",
260 __func__);
261 return ret;
262 }
263 break;
264 default:
265 return -EINVAL;
266 }
267
268 return count;
269 }
270
271 static const struct file_operations iio_debugfs_reg_fops = {
272 .open = simple_open,
273 .read = iio_debugfs_read_reg,
274 .write = iio_debugfs_write_reg,
275 };
276
277 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
278 {
279 debugfs_remove_recursive(indio_dev->debugfs_dentry);
280 }
281
282 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
283 {
284 struct dentry *d;
285
286 if (indio_dev->info->debugfs_reg_access == NULL)
287 return 0;
288
289 if (!iio_debugfs_dentry)
290 return 0;
291
292 indio_dev->debugfs_dentry =
293 debugfs_create_dir(dev_name(&indio_dev->dev),
294 iio_debugfs_dentry);
295 if (indio_dev->debugfs_dentry == NULL) {
296 dev_warn(indio_dev->dev.parent,
297 "Failed to create debugfs directory\n");
298 return -EFAULT;
299 }
300
301 d = debugfs_create_file("direct_reg_access", 0644,
302 indio_dev->debugfs_dentry,
303 indio_dev, &iio_debugfs_reg_fops);
304 if (!d) {
305 iio_device_unregister_debugfs(indio_dev);
306 return -ENOMEM;
307 }
308
309 return 0;
310 }
311 #else
312 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
313 {
314 return 0;
315 }
316
317 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
318 {
319 }
320 #endif /* CONFIG_DEBUG_FS */
321
322 static ssize_t iio_read_channel_ext_info(struct device *dev,
323 struct device_attribute *attr,
324 char *buf)
325 {
326 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
327 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
328 const struct iio_chan_spec_ext_info *ext_info;
329
330 ext_info = &this_attr->c->ext_info[this_attr->address];
331
332 return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
333 }
334
335 static ssize_t iio_write_channel_ext_info(struct device *dev,
336 struct device_attribute *attr,
337 const char *buf,
338 size_t len)
339 {
340 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
341 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
342 const struct iio_chan_spec_ext_info *ext_info;
343
344 ext_info = &this_attr->c->ext_info[this_attr->address];
345
346 return ext_info->write(indio_dev, ext_info->private,
347 this_attr->c, buf, len);
348 }
349
350 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
351 uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
352 {
353 const struct iio_enum *e = (const struct iio_enum *)priv;
354 unsigned int i;
355 size_t len = 0;
356
357 if (!e->num_items)
358 return 0;
359
360 for (i = 0; i < e->num_items; ++i)
361 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
362
363 /* replace last space with a newline */
364 buf[len - 1] = '\n';
365
366 return len;
367 }
368 EXPORT_SYMBOL_GPL(iio_enum_available_read);
369
370 ssize_t iio_enum_read(struct iio_dev *indio_dev,
371 uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
372 {
373 const struct iio_enum *e = (const struct iio_enum *)priv;
374 int i;
375
376 if (!e->get)
377 return -EINVAL;
378
379 i = e->get(indio_dev, chan);
380 if (i < 0)
381 return i;
382 else if (i >= e->num_items)
383 return -EINVAL;
384
385 return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
386 }
387 EXPORT_SYMBOL_GPL(iio_enum_read);
388
389 ssize_t iio_enum_write(struct iio_dev *indio_dev,
390 uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
391 size_t len)
392 {
393 const struct iio_enum *e = (const struct iio_enum *)priv;
394 unsigned int i;
395 int ret;
396
397 if (!e->set)
398 return -EINVAL;
399
400 for (i = 0; i < e->num_items; i++) {
401 if (sysfs_streq(buf, e->items[i]))
402 break;
403 }
404
405 if (i == e->num_items)
406 return -EINVAL;
407
408 ret = e->set(indio_dev, chan, i);
409 return ret ? ret : len;
410 }
411 EXPORT_SYMBOL_GPL(iio_enum_write);
412
413 /**
414 * iio_format_value() - Formats a IIO value into its string representation
415 * @buf: The buffer to which the formatted value gets written
416 * @type: One of the IIO_VAL_... constants. This decides how the val
417 * and val2 parameters are formatted.
418 * @size: Number of IIO value entries contained in vals
419 * @vals: Pointer to the values, exact meaning depends on the
420 * type parameter.
421 *
422 * Return: 0 by default, a negative number on failure or the
423 * total number of characters written for a type that belongs
424 * to the IIO_VAL_... constant.
425 */
426 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
427 {
428 unsigned long long tmp;
429 bool scale_db = false;
430
431 switch (type) {
432 case IIO_VAL_INT:
433 return sprintf(buf, "%d\n", vals[0]);
434 case IIO_VAL_INT_PLUS_MICRO_DB:
435 scale_db = true;
436 case IIO_VAL_INT_PLUS_MICRO:
437 if (vals[1] < 0)
438 return sprintf(buf, "-%d.%06u%s\n", abs(vals[0]),
439 -vals[1], scale_db ? " dB" : "");
440 else
441 return sprintf(buf, "%d.%06u%s\n", vals[0], vals[1],
442 scale_db ? " dB" : "");
443 case IIO_VAL_INT_PLUS_NANO:
444 if (vals[1] < 0)
445 return sprintf(buf, "-%d.%09u\n", abs(vals[0]),
446 -vals[1]);
447 else
448 return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
449 case IIO_VAL_FRACTIONAL:
450 tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
451 vals[1] = do_div(tmp, 1000000000LL);
452 vals[0] = tmp;
453 return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
454 case IIO_VAL_FRACTIONAL_LOG2:
455 tmp = (s64)vals[0] * 1000000000LL >> vals[1];
456 vals[1] = do_div(tmp, 1000000000LL);
457 vals[0] = tmp;
458 return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
459 case IIO_VAL_INT_MULTIPLE:
460 {
461 int i;
462 int len = 0;
463
464 for (i = 0; i < size; ++i)
465 len += snprintf(&buf[len], PAGE_SIZE - len, "%d ",
466 vals[i]);
467 len += snprintf(&buf[len], PAGE_SIZE - len, "\n");
468 return len;
469 }
470 default:
471 return 0;
472 }
473 }
474 EXPORT_SYMBOL_GPL(iio_format_value);
475
476 static ssize_t iio_read_channel_info(struct device *dev,
477 struct device_attribute *attr,
478 char *buf)
479 {
480 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
481 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
482 int vals[INDIO_MAX_RAW_ELEMENTS];
483 int ret;
484 int val_len = 2;
485
486 if (indio_dev->info->read_raw_multi)
487 ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
488 INDIO_MAX_RAW_ELEMENTS,
489 vals, &val_len,
490 this_attr->address);
491 else
492 ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
493 &vals[0], &vals[1], this_attr->address);
494
495 if (ret < 0)
496 return ret;
497
498 return iio_format_value(buf, ret, val_len, vals);
499 }
500
501 /**
502 * iio_str_to_fixpoint() - Parse a fixed-point number from a string
503 * @str: The string to parse
504 * @fract_mult: Multiplier for the first decimal place, should be a power of 10
505 * @integer: The integer part of the number
506 * @fract: The fractional part of the number
507 *
508 * Returns 0 on success, or a negative error code if the string could not be
509 * parsed.
510 */
511 int iio_str_to_fixpoint(const char *str, int fract_mult,
512 int *integer, int *fract)
513 {
514 int i = 0, f = 0;
515 bool integer_part = true, negative = false;
516
517 if (fract_mult == 0) {
518 *fract = 0;
519
520 return kstrtoint(str, 0, integer);
521 }
522
523 if (str[0] == '-') {
524 negative = true;
525 str++;
526 } else if (str[0] == '+') {
527 str++;
528 }
529
530 while (*str) {
531 if ('0' <= *str && *str <= '9') {
532 if (integer_part) {
533 i = i * 10 + *str - '0';
534 } else {
535 f += fract_mult * (*str - '0');
536 fract_mult /= 10;
537 }
538 } else if (*str == '\n') {
539 if (*(str + 1) == '\0')
540 break;
541 else
542 return -EINVAL;
543 } else if (*str == '.' && integer_part) {
544 integer_part = false;
545 } else {
546 return -EINVAL;
547 }
548 str++;
549 }
550
551 if (negative) {
552 if (i)
553 i = -i;
554 else
555 f = -f;
556 }
557
558 *integer = i;
559 *fract = f;
560
561 return 0;
562 }
563 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
564
565 static ssize_t iio_write_channel_info(struct device *dev,
566 struct device_attribute *attr,
567 const char *buf,
568 size_t len)
569 {
570 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
571 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
572 int ret, fract_mult = 100000;
573 int integer, fract;
574
575 /* Assumes decimal - precision based on number of digits */
576 if (!indio_dev->info->write_raw)
577 return -EINVAL;
578
579 if (indio_dev->info->write_raw_get_fmt)
580 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
581 this_attr->c, this_attr->address)) {
582 case IIO_VAL_INT:
583 fract_mult = 0;
584 break;
585 case IIO_VAL_INT_PLUS_MICRO:
586 fract_mult = 100000;
587 break;
588 case IIO_VAL_INT_PLUS_NANO:
589 fract_mult = 100000000;
590 break;
591 default:
592 return -EINVAL;
593 }
594
595 ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
596 if (ret)
597 return ret;
598
599 ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
600 integer, fract, this_attr->address);
601 if (ret)
602 return ret;
603
604 return len;
605 }
606
607 static
608 int __iio_device_attr_init(struct device_attribute *dev_attr,
609 const char *postfix,
610 struct iio_chan_spec const *chan,
611 ssize_t (*readfunc)(struct device *dev,
612 struct device_attribute *attr,
613 char *buf),
614 ssize_t (*writefunc)(struct device *dev,
615 struct device_attribute *attr,
616 const char *buf,
617 size_t len),
618 enum iio_shared_by shared_by)
619 {
620 int ret = 0;
621 char *name = NULL;
622 char *full_postfix;
623 sysfs_attr_init(&dev_attr->attr);
624
625 /* Build up postfix of <extend_name>_<modifier>_postfix */
626 if (chan->modified && (shared_by == IIO_SEPARATE)) {
627 if (chan->extend_name)
628 full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
629 iio_modifier_names[chan
630 ->channel2],
631 chan->extend_name,
632 postfix);
633 else
634 full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
635 iio_modifier_names[chan
636 ->channel2],
637 postfix);
638 } else {
639 if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
640 full_postfix = kstrdup(postfix, GFP_KERNEL);
641 else
642 full_postfix = kasprintf(GFP_KERNEL,
643 "%s_%s",
644 chan->extend_name,
645 postfix);
646 }
647 if (full_postfix == NULL)
648 return -ENOMEM;
649
650 if (chan->differential) { /* Differential can not have modifier */
651 switch (shared_by) {
652 case IIO_SHARED_BY_ALL:
653 name = kasprintf(GFP_KERNEL, "%s", full_postfix);
654 break;
655 case IIO_SHARED_BY_DIR:
656 name = kasprintf(GFP_KERNEL, "%s_%s",
657 iio_direction[chan->output],
658 full_postfix);
659 break;
660 case IIO_SHARED_BY_TYPE:
661 name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
662 iio_direction[chan->output],
663 iio_chan_type_name_spec[chan->type],
664 iio_chan_type_name_spec[chan->type],
665 full_postfix);
666 break;
667 case IIO_SEPARATE:
668 if (!chan->indexed) {
669 WARN(1, "Differential channels must be indexed\n");
670 ret = -EINVAL;
671 goto error_free_full_postfix;
672 }
673 name = kasprintf(GFP_KERNEL,
674 "%s_%s%d-%s%d_%s",
675 iio_direction[chan->output],
676 iio_chan_type_name_spec[chan->type],
677 chan->channel,
678 iio_chan_type_name_spec[chan->type],
679 chan->channel2,
680 full_postfix);
681 break;
682 }
683 } else { /* Single ended */
684 switch (shared_by) {
685 case IIO_SHARED_BY_ALL:
686 name = kasprintf(GFP_KERNEL, "%s", full_postfix);
687 break;
688 case IIO_SHARED_BY_DIR:
689 name = kasprintf(GFP_KERNEL, "%s_%s",
690 iio_direction[chan->output],
691 full_postfix);
692 break;
693 case IIO_SHARED_BY_TYPE:
694 name = kasprintf(GFP_KERNEL, "%s_%s_%s",
695 iio_direction[chan->output],
696 iio_chan_type_name_spec[chan->type],
697 full_postfix);
698 break;
699
700 case IIO_SEPARATE:
701 if (chan->indexed)
702 name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
703 iio_direction[chan->output],
704 iio_chan_type_name_spec[chan->type],
705 chan->channel,
706 full_postfix);
707 else
708 name = kasprintf(GFP_KERNEL, "%s_%s_%s",
709 iio_direction[chan->output],
710 iio_chan_type_name_spec[chan->type],
711 full_postfix);
712 break;
713 }
714 }
715 if (name == NULL) {
716 ret = -ENOMEM;
717 goto error_free_full_postfix;
718 }
719 dev_attr->attr.name = name;
720
721 if (readfunc) {
722 dev_attr->attr.mode |= S_IRUGO;
723 dev_attr->show = readfunc;
724 }
725
726 if (writefunc) {
727 dev_attr->attr.mode |= S_IWUSR;
728 dev_attr->store = writefunc;
729 }
730
731 error_free_full_postfix:
732 kfree(full_postfix);
733
734 return ret;
735 }
736
737 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
738 {
739 kfree(dev_attr->attr.name);
740 }
741
742 int __iio_add_chan_devattr(const char *postfix,
743 struct iio_chan_spec const *chan,
744 ssize_t (*readfunc)(struct device *dev,
745 struct device_attribute *attr,
746 char *buf),
747 ssize_t (*writefunc)(struct device *dev,
748 struct device_attribute *attr,
749 const char *buf,
750 size_t len),
751 u64 mask,
752 enum iio_shared_by shared_by,
753 struct device *dev,
754 struct list_head *attr_list)
755 {
756 int ret;
757 struct iio_dev_attr *iio_attr, *t;
758
759 iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
760 if (iio_attr == NULL)
761 return -ENOMEM;
762 ret = __iio_device_attr_init(&iio_attr->dev_attr,
763 postfix, chan,
764 readfunc, writefunc, shared_by);
765 if (ret)
766 goto error_iio_dev_attr_free;
767 iio_attr->c = chan;
768 iio_attr->address = mask;
769 list_for_each_entry(t, attr_list, l)
770 if (strcmp(t->dev_attr.attr.name,
771 iio_attr->dev_attr.attr.name) == 0) {
772 if (shared_by == IIO_SEPARATE)
773 dev_err(dev, "tried to double register : %s\n",
774 t->dev_attr.attr.name);
775 ret = -EBUSY;
776 goto error_device_attr_deinit;
777 }
778 list_add(&iio_attr->l, attr_list);
779
780 return 0;
781
782 error_device_attr_deinit:
783 __iio_device_attr_deinit(&iio_attr->dev_attr);
784 error_iio_dev_attr_free:
785 kfree(iio_attr);
786 return ret;
787 }
788
789 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
790 struct iio_chan_spec const *chan,
791 enum iio_shared_by shared_by,
792 const long *infomask)
793 {
794 int i, ret, attrcount = 0;
795
796 for_each_set_bit(i, infomask, sizeof(infomask)*8) {
797 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
798 return -EINVAL;
799 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
800 chan,
801 &iio_read_channel_info,
802 &iio_write_channel_info,
803 i,
804 shared_by,
805 &indio_dev->dev,
806 &indio_dev->channel_attr_list);
807 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
808 continue;
809 else if (ret < 0)
810 return ret;
811 attrcount++;
812 }
813
814 return attrcount;
815 }
816
817 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
818 struct iio_chan_spec const *chan)
819 {
820 int ret, attrcount = 0;
821 const struct iio_chan_spec_ext_info *ext_info;
822
823 if (chan->channel < 0)
824 return 0;
825 ret = iio_device_add_info_mask_type(indio_dev, chan,
826 IIO_SEPARATE,
827 &chan->info_mask_separate);
828 if (ret < 0)
829 return ret;
830 attrcount += ret;
831
832 ret = iio_device_add_info_mask_type(indio_dev, chan,
833 IIO_SHARED_BY_TYPE,
834 &chan->info_mask_shared_by_type);
835 if (ret < 0)
836 return ret;
837 attrcount += ret;
838
839 ret = iio_device_add_info_mask_type(indio_dev, chan,
840 IIO_SHARED_BY_DIR,
841 &chan->info_mask_shared_by_dir);
842 if (ret < 0)
843 return ret;
844 attrcount += ret;
845
846 ret = iio_device_add_info_mask_type(indio_dev, chan,
847 IIO_SHARED_BY_ALL,
848 &chan->info_mask_shared_by_all);
849 if (ret < 0)
850 return ret;
851 attrcount += ret;
852
853 if (chan->ext_info) {
854 unsigned int i = 0;
855 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
856 ret = __iio_add_chan_devattr(ext_info->name,
857 chan,
858 ext_info->read ?
859 &iio_read_channel_ext_info : NULL,
860 ext_info->write ?
861 &iio_write_channel_ext_info : NULL,
862 i,
863 ext_info->shared,
864 &indio_dev->dev,
865 &indio_dev->channel_attr_list);
866 i++;
867 if (ret == -EBUSY && ext_info->shared)
868 continue;
869
870 if (ret)
871 return ret;
872
873 attrcount++;
874 }
875 }
876
877 return attrcount;
878 }
879
880 /**
881 * iio_free_chan_devattr_list() - Free a list of IIO device attributes
882 * @attr_list: List of IIO device attributes
883 *
884 * This function frees the memory allocated for each of the IIO device
885 * attributes in the list.
886 */
887 void iio_free_chan_devattr_list(struct list_head *attr_list)
888 {
889 struct iio_dev_attr *p, *n;
890
891 list_for_each_entry_safe(p, n, attr_list, l) {
892 kfree(p->dev_attr.attr.name);
893 list_del(&p->l);
894 kfree(p);
895 }
896 }
897
898 static ssize_t iio_show_dev_name(struct device *dev,
899 struct device_attribute *attr,
900 char *buf)
901 {
902 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
903 return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
904 }
905
906 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
907
908 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
909 {
910 int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
911 struct iio_dev_attr *p;
912 struct attribute **attr;
913
914 /* First count elements in any existing group */
915 if (indio_dev->info->attrs) {
916 attr = indio_dev->info->attrs->attrs;
917 while (*attr++ != NULL)
918 attrcount_orig++;
919 }
920 attrcount = attrcount_orig;
921 /*
922 * New channel registration method - relies on the fact a group does
923 * not need to be initialized if its name is NULL.
924 */
925 if (indio_dev->channels)
926 for (i = 0; i < indio_dev->num_channels; i++) {
927 ret = iio_device_add_channel_sysfs(indio_dev,
928 &indio_dev
929 ->channels[i]);
930 if (ret < 0)
931 goto error_clear_attrs;
932 attrcount += ret;
933 }
934
935 if (indio_dev->name)
936 attrcount++;
937
938 indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
939 sizeof(indio_dev->chan_attr_group.attrs[0]),
940 GFP_KERNEL);
941 if (indio_dev->chan_attr_group.attrs == NULL) {
942 ret = -ENOMEM;
943 goto error_clear_attrs;
944 }
945 /* Copy across original attributes */
946 if (indio_dev->info->attrs)
947 memcpy(indio_dev->chan_attr_group.attrs,
948 indio_dev->info->attrs->attrs,
949 sizeof(indio_dev->chan_attr_group.attrs[0])
950 *attrcount_orig);
951 attrn = attrcount_orig;
952 /* Add all elements from the list. */
953 list_for_each_entry(p, &indio_dev->channel_attr_list, l)
954 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
955 if (indio_dev->name)
956 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
957
958 indio_dev->groups[indio_dev->groupcounter++] =
959 &indio_dev->chan_attr_group;
960
961 return 0;
962
963 error_clear_attrs:
964 iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
965
966 return ret;
967 }
968
969 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
970 {
971
972 iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
973 kfree(indio_dev->chan_attr_group.attrs);
974 indio_dev->chan_attr_group.attrs = NULL;
975 }
976
977 static void iio_dev_release(struct device *device)
978 {
979 struct iio_dev *indio_dev = dev_to_iio_dev(device);
980 if (indio_dev->modes & (INDIO_BUFFER_TRIGGERED | INDIO_EVENT_TRIGGERED))
981 iio_device_unregister_trigger_consumer(indio_dev);
982 iio_device_unregister_eventset(indio_dev);
983 iio_device_unregister_sysfs(indio_dev);
984
985 iio_buffer_put(indio_dev->buffer);
986
987 ida_simple_remove(&iio_ida, indio_dev->id);
988 kfree(indio_dev);
989 }
990
991 struct device_type iio_device_type = {
992 .name = "iio_device",
993 .release = iio_dev_release,
994 };
995
996 /**
997 * iio_device_alloc() - allocate an iio_dev from a driver
998 * @sizeof_priv: Space to allocate for private structure.
999 **/
1000 struct iio_dev *iio_device_alloc(int sizeof_priv)
1001 {
1002 struct iio_dev *dev;
1003 size_t alloc_size;
1004
1005 alloc_size = sizeof(struct iio_dev);
1006 if (sizeof_priv) {
1007 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1008 alloc_size += sizeof_priv;
1009 }
1010 /* ensure 32-byte alignment of whole construct ? */
1011 alloc_size += IIO_ALIGN - 1;
1012
1013 dev = kzalloc(alloc_size, GFP_KERNEL);
1014
1015 if (dev) {
1016 dev->dev.groups = dev->groups;
1017 dev->dev.type = &iio_device_type;
1018 dev->dev.bus = &iio_bus_type;
1019 device_initialize(&dev->dev);
1020 dev_set_drvdata(&dev->dev, (void *)dev);
1021 mutex_init(&dev->mlock);
1022 mutex_init(&dev->info_exist_lock);
1023 INIT_LIST_HEAD(&dev->channel_attr_list);
1024
1025 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1026 if (dev->id < 0) {
1027 /* cannot use a dev_err as the name isn't available */
1028 pr_err("failed to get device id\n");
1029 kfree(dev);
1030 return NULL;
1031 }
1032 dev_set_name(&dev->dev, "iio:device%d", dev->id);
1033 INIT_LIST_HEAD(&dev->buffer_list);
1034 }
1035
1036 return dev;
1037 }
1038 EXPORT_SYMBOL(iio_device_alloc);
1039
1040 /**
1041 * iio_device_free() - free an iio_dev from a driver
1042 * @dev: the iio_dev associated with the device
1043 **/
1044 void iio_device_free(struct iio_dev *dev)
1045 {
1046 if (dev)
1047 put_device(&dev->dev);
1048 }
1049 EXPORT_SYMBOL(iio_device_free);
1050
1051 static void devm_iio_device_release(struct device *dev, void *res)
1052 {
1053 iio_device_free(*(struct iio_dev **)res);
1054 }
1055
1056 static int devm_iio_device_match(struct device *dev, void *res, void *data)
1057 {
1058 struct iio_dev **r = res;
1059 if (!r || !*r) {
1060 WARN_ON(!r || !*r);
1061 return 0;
1062 }
1063 return *r == data;
1064 }
1065
1066 /**
1067 * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1068 * @dev: Device to allocate iio_dev for
1069 * @sizeof_priv: Space to allocate for private structure.
1070 *
1071 * Managed iio_device_alloc. iio_dev allocated with this function is
1072 * automatically freed on driver detach.
1073 *
1074 * If an iio_dev allocated with this function needs to be freed separately,
1075 * devm_iio_device_free() must be used.
1076 *
1077 * RETURNS:
1078 * Pointer to allocated iio_dev on success, NULL on failure.
1079 */
1080 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1081 {
1082 struct iio_dev **ptr, *iio_dev;
1083
1084 ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1085 GFP_KERNEL);
1086 if (!ptr)
1087 return NULL;
1088
1089 iio_dev = iio_device_alloc(sizeof_priv);
1090 if (iio_dev) {
1091 *ptr = iio_dev;
1092 devres_add(dev, ptr);
1093 } else {
1094 devres_free(ptr);
1095 }
1096
1097 return iio_dev;
1098 }
1099 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1100
1101 /**
1102 * devm_iio_device_free - Resource-managed iio_device_free()
1103 * @dev: Device this iio_dev belongs to
1104 * @iio_dev: the iio_dev associated with the device
1105 *
1106 * Free iio_dev allocated with devm_iio_device_alloc().
1107 */
1108 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1109 {
1110 int rc;
1111
1112 rc = devres_release(dev, devm_iio_device_release,
1113 devm_iio_device_match, iio_dev);
1114 WARN_ON(rc);
1115 }
1116 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1117
1118 /**
1119 * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1120 * @inode: Inode structure for identifying the device in the file system
1121 * @filp: File structure for iio device used to keep and later access
1122 * private data
1123 *
1124 * Return: 0 on success or -EBUSY if the device is already opened
1125 **/
1126 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1127 {
1128 struct iio_dev *indio_dev = container_of(inode->i_cdev,
1129 struct iio_dev, chrdev);
1130
1131 if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1132 return -EBUSY;
1133
1134 iio_device_get(indio_dev);
1135
1136 filp->private_data = indio_dev;
1137
1138 return 0;
1139 }
1140
1141 /**
1142 * iio_chrdev_release() - chrdev file close buffer access and ioctls
1143 * @inode: Inode structure pointer for the char device
1144 * @filp: File structure pointer for the char device
1145 *
1146 * Return: 0 for successful release
1147 */
1148 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1149 {
1150 struct iio_dev *indio_dev = container_of(inode->i_cdev,
1151 struct iio_dev, chrdev);
1152 clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1153 iio_device_put(indio_dev);
1154
1155 return 0;
1156 }
1157
1158 /* Somewhat of a cross file organization violation - ioctls here are actually
1159 * event related */
1160 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1161 {
1162 struct iio_dev *indio_dev = filp->private_data;
1163 int __user *ip = (int __user *)arg;
1164 int fd;
1165
1166 if (!indio_dev->info)
1167 return -ENODEV;
1168
1169 if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1170 fd = iio_event_getfd(indio_dev);
1171 if (fd < 0)
1172 return fd;
1173 if (copy_to_user(ip, &fd, sizeof(fd)))
1174 return -EFAULT;
1175 return 0;
1176 }
1177 return -EINVAL;
1178 }
1179
1180 static const struct file_operations iio_buffer_fileops = {
1181 .read = iio_buffer_read_first_n_outer_addr,
1182 .release = iio_chrdev_release,
1183 .open = iio_chrdev_open,
1184 .poll = iio_buffer_poll_addr,
1185 .owner = THIS_MODULE,
1186 .llseek = noop_llseek,
1187 .unlocked_ioctl = iio_ioctl,
1188 .compat_ioctl = iio_ioctl,
1189 };
1190
1191 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1192 {
1193 int i, j;
1194 const struct iio_chan_spec *channels = indio_dev->channels;
1195
1196 if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1197 return 0;
1198
1199 for (i = 0; i < indio_dev->num_channels - 1; i++) {
1200 if (channels[i].scan_index < 0)
1201 continue;
1202 for (j = i + 1; j < indio_dev->num_channels; j++)
1203 if (channels[i].scan_index == channels[j].scan_index) {
1204 dev_err(&indio_dev->dev,
1205 "Duplicate scan index %d\n",
1206 channels[i].scan_index);
1207 return -EINVAL;
1208 }
1209 }
1210
1211 return 0;
1212 }
1213
1214 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1215
1216 /**
1217 * iio_device_register() - register a device with the IIO subsystem
1218 * @indio_dev: Device structure filled by the device driver
1219 **/
1220 int iio_device_register(struct iio_dev *indio_dev)
1221 {
1222 int ret;
1223
1224 /* If the calling driver did not initialize of_node, do it here */
1225 if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1226 indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1227
1228 ret = iio_check_unique_scan_index(indio_dev);
1229 if (ret < 0)
1230 return ret;
1231
1232 /* configure elements for the chrdev */
1233 indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1234
1235 ret = iio_device_register_debugfs(indio_dev);
1236 if (ret) {
1237 dev_err(indio_dev->dev.parent,
1238 "Failed to register debugfs interfaces\n");
1239 return ret;
1240 }
1241
1242 ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1243 if (ret) {
1244 dev_err(indio_dev->dev.parent,
1245 "Failed to create buffer sysfs interfaces\n");
1246 goto error_unreg_debugfs;
1247 }
1248
1249 ret = iio_device_register_sysfs(indio_dev);
1250 if (ret) {
1251 dev_err(indio_dev->dev.parent,
1252 "Failed to register sysfs interfaces\n");
1253 goto error_buffer_free_sysfs;
1254 }
1255 ret = iio_device_register_eventset(indio_dev);
1256 if (ret) {
1257 dev_err(indio_dev->dev.parent,
1258 "Failed to register event set\n");
1259 goto error_free_sysfs;
1260 }
1261 if (indio_dev->modes & (INDIO_BUFFER_TRIGGERED | INDIO_EVENT_TRIGGERED))
1262 iio_device_register_trigger_consumer(indio_dev);
1263
1264 if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1265 indio_dev->setup_ops == NULL)
1266 indio_dev->setup_ops = &noop_ring_setup_ops;
1267
1268 cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1269 indio_dev->chrdev.owner = indio_dev->info->driver_module;
1270 indio_dev->chrdev.kobj.parent = &indio_dev->dev.kobj;
1271 ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
1272 if (ret < 0)
1273 goto error_unreg_eventset;
1274
1275 ret = device_add(&indio_dev->dev);
1276 if (ret < 0)
1277 goto error_cdev_del;
1278
1279 return 0;
1280 error_cdev_del:
1281 cdev_del(&indio_dev->chrdev);
1282 error_unreg_eventset:
1283 iio_device_unregister_eventset(indio_dev);
1284 error_free_sysfs:
1285 iio_device_unregister_sysfs(indio_dev);
1286 error_buffer_free_sysfs:
1287 iio_buffer_free_sysfs_and_mask(indio_dev);
1288 error_unreg_debugfs:
1289 iio_device_unregister_debugfs(indio_dev);
1290 return ret;
1291 }
1292 EXPORT_SYMBOL(iio_device_register);
1293
1294 /**
1295 * iio_device_unregister() - unregister a device from the IIO subsystem
1296 * @indio_dev: Device structure representing the device.
1297 **/
1298 void iio_device_unregister(struct iio_dev *indio_dev)
1299 {
1300 mutex_lock(&indio_dev->info_exist_lock);
1301
1302 device_del(&indio_dev->dev);
1303
1304 if (indio_dev->chrdev.dev)
1305 cdev_del(&indio_dev->chrdev);
1306 iio_device_unregister_debugfs(indio_dev);
1307
1308 iio_disable_all_buffers(indio_dev);
1309
1310 indio_dev->info = NULL;
1311
1312 iio_device_wakeup_eventset(indio_dev);
1313 iio_buffer_wakeup_poll(indio_dev);
1314
1315 mutex_unlock(&indio_dev->info_exist_lock);
1316
1317 iio_buffer_free_sysfs_and_mask(indio_dev);
1318 }
1319 EXPORT_SYMBOL(iio_device_unregister);
1320
1321 static void devm_iio_device_unreg(struct device *dev, void *res)
1322 {
1323 iio_device_unregister(*(struct iio_dev **)res);
1324 }
1325
1326 /**
1327 * devm_iio_device_register - Resource-managed iio_device_register()
1328 * @dev: Device to allocate iio_dev for
1329 * @indio_dev: Device structure filled by the device driver
1330 *
1331 * Managed iio_device_register. The IIO device registered with this
1332 * function is automatically unregistered on driver detach. This function
1333 * calls iio_device_register() internally. Refer to that function for more
1334 * information.
1335 *
1336 * If an iio_dev registered with this function needs to be unregistered
1337 * separately, devm_iio_device_unregister() must be used.
1338 *
1339 * RETURNS:
1340 * 0 on success, negative error number on failure.
1341 */
1342 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev)
1343 {
1344 struct iio_dev **ptr;
1345 int ret;
1346
1347 ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1348 if (!ptr)
1349 return -ENOMEM;
1350
1351 *ptr = indio_dev;
1352 ret = iio_device_register(indio_dev);
1353 if (!ret)
1354 devres_add(dev, ptr);
1355 else
1356 devres_free(ptr);
1357
1358 return ret;
1359 }
1360 EXPORT_SYMBOL_GPL(devm_iio_device_register);
1361
1362 /**
1363 * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1364 * @dev: Device this iio_dev belongs to
1365 * @indio_dev: the iio_dev associated with the device
1366 *
1367 * Unregister iio_dev registered with devm_iio_device_register().
1368 */
1369 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1370 {
1371 int rc;
1372
1373 rc = devres_release(dev, devm_iio_device_unreg,
1374 devm_iio_device_match, indio_dev);
1375 WARN_ON(rc);
1376 }
1377 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1378
1379 /**
1380 * iio_device_claim_direct_mode - Keep device in direct mode
1381 * @indio_dev: the iio_dev associated with the device
1382 *
1383 * If the device is in direct mode it is guaranteed to stay
1384 * that way until iio_device_release_direct_mode() is called.
1385 *
1386 * Use with iio_device_release_direct_mode()
1387 *
1388 * Returns: 0 on success, -EBUSY on failure
1389 */
1390 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1391 {
1392 mutex_lock(&indio_dev->mlock);
1393
1394 if (iio_buffer_enabled(indio_dev)) {
1395 mutex_unlock(&indio_dev->mlock);
1396 return -EBUSY;
1397 }
1398 return 0;
1399 }
1400 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1401
1402 /**
1403 * iio_device_release_direct_mode - releases claim on direct mode
1404 * @indio_dev: the iio_dev associated with the device
1405 *
1406 * Release the claim. Device is no longer guaranteed to stay
1407 * in direct mode.
1408 *
1409 * Use with iio_device_claim_direct_mode()
1410 */
1411 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1412 {
1413 mutex_unlock(&indio_dev->mlock);
1414 }
1415 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1416
1417 subsys_initcall(iio_init);
1418 module_exit(iio_exit);
1419
1420 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1421 MODULE_DESCRIPTION("Industrial I/O core");
1422 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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