1 /* The industrial I/O core
3 * Copyright (c) 2008 Jonathan Cameron
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.
9 * Based on elements of hwmon and input subsystems.
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/idr.h>
15 #include <linux/kdev_t.h>
16 #include <linux/err.h>
17 #include <linux/device.h>
19 #include <linux/poll.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/iio/iio.h>
28 #include "iio_core_trigger.h"
29 #include <linux/iio/sysfs.h>
30 #include <linux/iio/events.h>
32 /* IDA to assign each registered device a unique id*/
33 static DEFINE_IDA(iio_ida);
35 static dev_t iio_devt;
37 #define IIO_DEV_MAX 256
38 struct bus_type iio_bus_type = {
41 EXPORT_SYMBOL(iio_bus_type);
43 static struct dentry *iio_debugfs_dentry;
45 static const char * const iio_direction[] = {
50 static const char * const iio_chan_type_name_spec[] = {
51 [IIO_VOLTAGE] = "voltage",
52 [IIO_CURRENT] = "current",
53 [IIO_POWER] = "power",
54 [IIO_ACCEL] = "accel",
55 [IIO_ANGL_VEL] = "anglvel",
57 [IIO_LIGHT] = "illuminance",
58 [IIO_INTENSITY] = "intensity",
59 [IIO_PROXIMITY] = "proximity",
61 [IIO_INCLI] = "incli",
64 [IIO_TIMESTAMP] = "timestamp",
65 [IIO_CAPACITANCE] = "capacitance",
66 [IIO_ALTVOLTAGE] = "altvoltage",
69 static const char * const iio_modifier_names[] = {
73 [IIO_MOD_LIGHT_BOTH] = "both",
74 [IIO_MOD_LIGHT_IR] = "ir",
77 /* relies on pairs of these shared then separate */
78 static const char * const iio_chan_info_postfix[] = {
79 [IIO_CHAN_INFO_RAW] = "raw",
80 [IIO_CHAN_INFO_PROCESSED] = "input",
81 [IIO_CHAN_INFO_SCALE] = "scale",
82 [IIO_CHAN_INFO_OFFSET] = "offset",
83 [IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
84 [IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
85 [IIO_CHAN_INFO_PEAK] = "peak_raw",
86 [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
87 [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
88 [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
89 [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
90 = "filter_low_pass_3db_frequency",
91 [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
92 [IIO_CHAN_INFO_FREQUENCY] = "frequency",
93 [IIO_CHAN_INFO_PHASE] = "phase",
96 const struct iio_chan_spec
97 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
101 for (i = 0; i < indio_dev->num_channels; i++)
102 if (indio_dev->channels[i].scan_index == si)
103 return &indio_dev->channels[i];
107 /* This turns up an awful lot */
108 ssize_t iio_read_const_attr(struct device *dev,
109 struct device_attribute *attr,
112 return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
114 EXPORT_SYMBOL(iio_read_const_attr);
116 static int __init iio_init(void)
120 /* Register sysfs bus */
121 ret = bus_register(&iio_bus_type);
124 "%s could not register bus type\n",
129 ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
131 printk(KERN_ERR "%s: failed to allocate char dev region\n",
133 goto error_unregister_bus_type;
136 iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
140 error_unregister_bus_type:
141 bus_unregister(&iio_bus_type);
146 static void __exit iio_exit(void)
149 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
150 bus_unregister(&iio_bus_type);
151 debugfs_remove(iio_debugfs_dentry);
154 #if defined(CONFIG_DEBUG_FS)
155 static int iio_debugfs_open(struct inode *inode, struct file *file)
157 if (inode->i_private)
158 file->private_data = inode->i_private;
163 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
164 size_t count, loff_t *ppos)
166 struct iio_dev *indio_dev = file->private_data;
172 ret = indio_dev->info->debugfs_reg_access(indio_dev,
173 indio_dev->cached_reg_addr,
176 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
178 len = snprintf(buf, sizeof(buf), "0x%X\n", val);
180 return simple_read_from_buffer(userbuf, count, ppos, buf, len);
183 static ssize_t iio_debugfs_write_reg(struct file *file,
184 const char __user *userbuf, size_t count, loff_t *ppos)
186 struct iio_dev *indio_dev = file->private_data;
191 count = min_t(size_t, count, (sizeof(buf)-1));
192 if (copy_from_user(buf, userbuf, count))
197 ret = sscanf(buf, "%i %i", ®, &val);
201 indio_dev->cached_reg_addr = reg;
204 indio_dev->cached_reg_addr = reg;
205 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
208 dev_err(indio_dev->dev.parent, "%s: write failed\n",
220 static const struct file_operations iio_debugfs_reg_fops = {
221 .open = iio_debugfs_open,
222 .read = iio_debugfs_read_reg,
223 .write = iio_debugfs_write_reg,
226 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
228 debugfs_remove_recursive(indio_dev->debugfs_dentry);
231 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
235 if (indio_dev->info->debugfs_reg_access == NULL)
238 if (IS_ERR(iio_debugfs_dentry))
241 indio_dev->debugfs_dentry =
242 debugfs_create_dir(dev_name(&indio_dev->dev),
244 if (IS_ERR(indio_dev->debugfs_dentry))
245 return PTR_ERR(indio_dev->debugfs_dentry);
247 if (indio_dev->debugfs_dentry == NULL) {
248 dev_warn(indio_dev->dev.parent,
249 "Failed to create debugfs directory\n");
253 d = debugfs_create_file("direct_reg_access", 0644,
254 indio_dev->debugfs_dentry,
255 indio_dev, &iio_debugfs_reg_fops);
257 iio_device_unregister_debugfs(indio_dev);
264 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
269 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
272 #endif /* CONFIG_DEBUG_FS */
274 static ssize_t iio_read_channel_ext_info(struct device *dev,
275 struct device_attribute *attr,
278 struct iio_dev *indio_dev = dev_get_drvdata(dev);
279 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
280 const struct iio_chan_spec_ext_info *ext_info;
282 ext_info = &this_attr->c->ext_info[this_attr->address];
284 return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
287 static ssize_t iio_write_channel_ext_info(struct device *dev,
288 struct device_attribute *attr,
292 struct iio_dev *indio_dev = dev_get_drvdata(dev);
293 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
294 const struct iio_chan_spec_ext_info *ext_info;
296 ext_info = &this_attr->c->ext_info[this_attr->address];
298 return ext_info->write(indio_dev, ext_info->private,
299 this_attr->c, buf, len);
302 static ssize_t iio_read_channel_info(struct device *dev,
303 struct device_attribute *attr,
306 struct iio_dev *indio_dev = dev_get_drvdata(dev);
307 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
309 int ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
310 &val, &val2, this_attr->address);
315 if (ret == IIO_VAL_INT)
316 return sprintf(buf, "%d\n", val);
317 else if (ret == IIO_VAL_INT_PLUS_MICRO) {
319 return sprintf(buf, "-%d.%06u\n", val, -val2);
321 return sprintf(buf, "%d.%06u\n", val, val2);
322 } else if (ret == IIO_VAL_INT_PLUS_NANO) {
324 return sprintf(buf, "-%d.%09u\n", val, -val2);
326 return sprintf(buf, "%d.%09u\n", val, val2);
331 static ssize_t iio_write_channel_info(struct device *dev,
332 struct device_attribute *attr,
336 struct iio_dev *indio_dev = dev_get_drvdata(dev);
337 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
338 int ret, integer = 0, fract = 0, fract_mult = 100000;
339 bool integer_part = true, negative = false;
341 /* Assumes decimal - precision based on number of digits */
342 if (!indio_dev->info->write_raw)
345 if (indio_dev->info->write_raw_get_fmt)
346 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
347 this_attr->c, this_attr->address)) {
348 case IIO_VAL_INT_PLUS_MICRO:
351 case IIO_VAL_INT_PLUS_NANO:
352 fract_mult = 100000000;
364 if ('0' <= *buf && *buf <= '9') {
366 integer = integer*10 + *buf - '0';
368 fract += fract_mult*(*buf - '0');
373 } else if (*buf == '\n') {
374 if (*(buf + 1) == '\0')
378 } else if (*buf == '.') {
379 integer_part = false;
392 ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
393 integer, fract, this_attr->address);
401 int __iio_device_attr_init(struct device_attribute *dev_attr,
403 struct iio_chan_spec const *chan,
404 ssize_t (*readfunc)(struct device *dev,
405 struct device_attribute *attr,
407 ssize_t (*writefunc)(struct device *dev,
408 struct device_attribute *attr,
414 char *name_format, *full_postfix;
415 sysfs_attr_init(&dev_attr->attr);
417 /* Build up postfix of <extend_name>_<modifier>_postfix */
418 if (chan->modified && !generic) {
419 if (chan->extend_name)
420 full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
421 iio_modifier_names[chan
426 full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
427 iio_modifier_names[chan
431 if (chan->extend_name == NULL)
432 full_postfix = kstrdup(postfix, GFP_KERNEL);
434 full_postfix = kasprintf(GFP_KERNEL,
439 if (full_postfix == NULL) {
444 if (chan->differential) { /* Differential can not have modifier */
447 = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
448 iio_direction[chan->output],
449 iio_chan_type_name_spec[chan->type],
450 iio_chan_type_name_spec[chan->type],
452 else if (chan->indexed)
454 = kasprintf(GFP_KERNEL, "%s_%s%d-%s%d_%s",
455 iio_direction[chan->output],
456 iio_chan_type_name_spec[chan->type],
458 iio_chan_type_name_spec[chan->type],
462 WARN_ON("Differential channels must be indexed\n");
464 goto error_free_full_postfix;
466 } else { /* Single ended */
469 = kasprintf(GFP_KERNEL, "%s_%s_%s",
470 iio_direction[chan->output],
471 iio_chan_type_name_spec[chan->type],
473 else if (chan->indexed)
475 = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
476 iio_direction[chan->output],
477 iio_chan_type_name_spec[chan->type],
482 = kasprintf(GFP_KERNEL, "%s_%s_%s",
483 iio_direction[chan->output],
484 iio_chan_type_name_spec[chan->type],
487 if (name_format == NULL) {
489 goto error_free_full_postfix;
491 dev_attr->attr.name = kasprintf(GFP_KERNEL,
495 if (dev_attr->attr.name == NULL) {
497 goto error_free_name_format;
501 dev_attr->attr.mode |= S_IRUGO;
502 dev_attr->show = readfunc;
506 dev_attr->attr.mode |= S_IWUSR;
507 dev_attr->store = writefunc;
514 error_free_name_format:
516 error_free_full_postfix:
522 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
524 kfree(dev_attr->attr.name);
527 int __iio_add_chan_devattr(const char *postfix,
528 struct iio_chan_spec const *chan,
529 ssize_t (*readfunc)(struct device *dev,
530 struct device_attribute *attr,
532 ssize_t (*writefunc)(struct device *dev,
533 struct device_attribute *attr,
539 struct list_head *attr_list)
542 struct iio_dev_attr *iio_attr, *t;
544 iio_attr = kzalloc(sizeof *iio_attr, GFP_KERNEL);
545 if (iio_attr == NULL) {
549 ret = __iio_device_attr_init(&iio_attr->dev_attr,
551 readfunc, writefunc, generic);
553 goto error_iio_dev_attr_free;
555 iio_attr->address = mask;
556 list_for_each_entry(t, attr_list, l)
557 if (strcmp(t->dev_attr.attr.name,
558 iio_attr->dev_attr.attr.name) == 0) {
560 dev_err(dev, "tried to double register : %s\n",
561 t->dev_attr.attr.name);
563 goto error_device_attr_deinit;
565 list_add(&iio_attr->l, attr_list);
569 error_device_attr_deinit:
570 __iio_device_attr_deinit(&iio_attr->dev_attr);
571 error_iio_dev_attr_free:
577 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
578 struct iio_chan_spec const *chan)
580 int ret, attrcount = 0;
582 const struct iio_chan_spec_ext_info *ext_info;
584 if (chan->channel < 0)
586 for_each_set_bit(i, &chan->info_mask, sizeof(long)*8) {
587 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i/2],
589 &iio_read_channel_info,
590 &iio_write_channel_info,
594 &indio_dev->channel_attr_list);
595 if (ret == -EBUSY && (i%2 == 0)) {
604 if (chan->ext_info) {
606 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
607 ret = __iio_add_chan_devattr(ext_info->name,
610 &iio_read_channel_ext_info : NULL,
612 &iio_write_channel_ext_info : NULL,
616 &indio_dev->channel_attr_list);
618 if (ret == -EBUSY && ext_info->shared)
633 static void iio_device_remove_and_free_read_attr(struct iio_dev *indio_dev,
634 struct iio_dev_attr *p)
636 kfree(p->dev_attr.attr.name);
640 static ssize_t iio_show_dev_name(struct device *dev,
641 struct device_attribute *attr,
644 struct iio_dev *indio_dev = dev_get_drvdata(dev);
645 return sprintf(buf, "%s\n", indio_dev->name);
648 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
650 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
652 int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
653 struct iio_dev_attr *p, *n;
654 struct attribute **attr;
656 /* First count elements in any existing group */
657 if (indio_dev->info->attrs) {
658 attr = indio_dev->info->attrs->attrs;
659 while (*attr++ != NULL)
662 attrcount = attrcount_orig;
664 * New channel registration method - relies on the fact a group does
665 * not need to be initialized if it is name is NULL.
667 INIT_LIST_HEAD(&indio_dev->channel_attr_list);
668 if (indio_dev->channels)
669 for (i = 0; i < indio_dev->num_channels; i++) {
670 ret = iio_device_add_channel_sysfs(indio_dev,
674 goto error_clear_attrs;
681 indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
682 sizeof(indio_dev->chan_attr_group.attrs[0]),
684 if (indio_dev->chan_attr_group.attrs == NULL) {
686 goto error_clear_attrs;
688 /* Copy across original attributes */
689 if (indio_dev->info->attrs)
690 memcpy(indio_dev->chan_attr_group.attrs,
691 indio_dev->info->attrs->attrs,
692 sizeof(indio_dev->chan_attr_group.attrs[0])
694 attrn = attrcount_orig;
695 /* Add all elements from the list. */
696 list_for_each_entry(p, &indio_dev->channel_attr_list, l)
697 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
699 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
701 indio_dev->groups[indio_dev->groupcounter++] =
702 &indio_dev->chan_attr_group;
707 list_for_each_entry_safe(p, n,
708 &indio_dev->channel_attr_list, l) {
710 iio_device_remove_and_free_read_attr(indio_dev, p);
716 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
719 struct iio_dev_attr *p, *n;
721 list_for_each_entry_safe(p, n, &indio_dev->channel_attr_list, l) {
723 iio_device_remove_and_free_read_attr(indio_dev, p);
725 kfree(indio_dev->chan_attr_group.attrs);
728 static void iio_dev_release(struct device *device)
730 struct iio_dev *indio_dev = container_of(device, struct iio_dev, dev);
731 cdev_del(&indio_dev->chrdev);
732 if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
733 iio_device_unregister_trigger_consumer(indio_dev);
734 iio_device_unregister_eventset(indio_dev);
735 iio_device_unregister_sysfs(indio_dev);
736 iio_device_unregister_debugfs(indio_dev);
739 static struct device_type iio_dev_type = {
740 .name = "iio_device",
741 .release = iio_dev_release,
744 struct iio_dev *iio_device_alloc(int sizeof_priv)
749 alloc_size = sizeof(struct iio_dev);
751 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
752 alloc_size += sizeof_priv;
754 /* ensure 32-byte alignment of whole construct ? */
755 alloc_size += IIO_ALIGN - 1;
757 dev = kzalloc(alloc_size, GFP_KERNEL);
760 dev->dev.groups = dev->groups;
761 dev->dev.type = &iio_dev_type;
762 dev->dev.bus = &iio_bus_type;
763 device_initialize(&dev->dev);
764 dev_set_drvdata(&dev->dev, (void *)dev);
765 mutex_init(&dev->mlock);
766 mutex_init(&dev->info_exist_lock);
768 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
770 /* cannot use a dev_err as the name isn't available */
771 printk(KERN_ERR "Failed to get id\n");
775 dev_set_name(&dev->dev, "iio:device%d", dev->id);
780 EXPORT_SYMBOL(iio_device_alloc);
782 void iio_device_free(struct iio_dev *dev)
785 ida_simple_remove(&iio_ida, dev->id);
789 EXPORT_SYMBOL(iio_device_free);
792 * iio_chrdev_open() - chrdev file open for buffer access and ioctls
794 static int iio_chrdev_open(struct inode *inode, struct file *filp)
796 struct iio_dev *indio_dev = container_of(inode->i_cdev,
797 struct iio_dev, chrdev);
799 if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
802 filp->private_data = indio_dev;
808 * iio_chrdev_release() - chrdev file close buffer access and ioctls
810 static int iio_chrdev_release(struct inode *inode, struct file *filp)
812 struct iio_dev *indio_dev = container_of(inode->i_cdev,
813 struct iio_dev, chrdev);
814 clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
818 /* Somewhat of a cross file organization violation - ioctls here are actually
820 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
822 struct iio_dev *indio_dev = filp->private_data;
823 int __user *ip = (int __user *)arg;
826 if (cmd == IIO_GET_EVENT_FD_IOCTL) {
827 fd = iio_event_getfd(indio_dev);
828 if (copy_to_user(ip, &fd, sizeof(fd)))
835 static const struct file_operations iio_buffer_fileops = {
836 .read = iio_buffer_read_first_n_outer_addr,
837 .release = iio_chrdev_release,
838 .open = iio_chrdev_open,
839 .poll = iio_buffer_poll_addr,
840 .owner = THIS_MODULE,
841 .llseek = noop_llseek,
842 .unlocked_ioctl = iio_ioctl,
843 .compat_ioctl = iio_ioctl,
846 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
848 int iio_device_register(struct iio_dev *indio_dev)
852 /* configure elements for the chrdev */
853 indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
855 ret = iio_device_register_debugfs(indio_dev);
857 dev_err(indio_dev->dev.parent,
858 "Failed to register debugfs interfaces\n");
861 ret = iio_device_register_sysfs(indio_dev);
863 dev_err(indio_dev->dev.parent,
864 "Failed to register sysfs interfaces\n");
865 goto error_unreg_debugfs;
867 ret = iio_device_register_eventset(indio_dev);
869 dev_err(indio_dev->dev.parent,
870 "Failed to register event set\n");
871 goto error_free_sysfs;
873 if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
874 iio_device_register_trigger_consumer(indio_dev);
876 if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
877 indio_dev->setup_ops == NULL)
878 indio_dev->setup_ops = &noop_ring_setup_ops;
880 ret = device_add(&indio_dev->dev);
882 goto error_unreg_eventset;
883 cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
884 indio_dev->chrdev.owner = indio_dev->info->driver_module;
885 ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
887 goto error_del_device;
891 device_del(&indio_dev->dev);
892 error_unreg_eventset:
893 iio_device_unregister_eventset(indio_dev);
895 iio_device_unregister_sysfs(indio_dev);
897 iio_device_unregister_debugfs(indio_dev);
901 EXPORT_SYMBOL(iio_device_register);
903 void iio_device_unregister(struct iio_dev *indio_dev)
905 mutex_lock(&indio_dev->info_exist_lock);
906 indio_dev->info = NULL;
907 mutex_unlock(&indio_dev->info_exist_lock);
908 device_unregister(&indio_dev->dev);
910 EXPORT_SYMBOL(iio_device_unregister);
911 subsys_initcall(iio_init);
912 module_exit(iio_exit);
914 MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
915 MODULE_DESCRIPTION("Industrial I/O core");
916 MODULE_LICENSE("GPL");