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",
94 [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
97 const struct iio_chan_spec
98 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
102 for (i = 0; i < indio_dev->num_channels; i++)
103 if (indio_dev->channels[i].scan_index == si)
104 return &indio_dev->channels[i];
108 /* This turns up an awful lot */
109 ssize_t iio_read_const_attr(struct device *dev,
110 struct device_attribute *attr,
113 return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
115 EXPORT_SYMBOL(iio_read_const_attr);
117 static int __init iio_init(void)
121 /* Register sysfs bus */
122 ret = bus_register(&iio_bus_type);
125 "%s could not register bus type\n",
130 ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
132 printk(KERN_ERR "%s: failed to allocate char dev region\n",
134 goto error_unregister_bus_type;
137 iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
141 error_unregister_bus_type:
142 bus_unregister(&iio_bus_type);
147 static void __exit iio_exit(void)
150 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
151 bus_unregister(&iio_bus_type);
152 debugfs_remove(iio_debugfs_dentry);
155 #if defined(CONFIG_DEBUG_FS)
156 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
157 size_t count, loff_t *ppos)
159 struct iio_dev *indio_dev = file->private_data;
165 ret = indio_dev->info->debugfs_reg_access(indio_dev,
166 indio_dev->cached_reg_addr,
169 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
171 len = snprintf(buf, sizeof(buf), "0x%X\n", val);
173 return simple_read_from_buffer(userbuf, count, ppos, buf, len);
176 static ssize_t iio_debugfs_write_reg(struct file *file,
177 const char __user *userbuf, size_t count, loff_t *ppos)
179 struct iio_dev *indio_dev = file->private_data;
184 count = min_t(size_t, count, (sizeof(buf)-1));
185 if (copy_from_user(buf, userbuf, count))
190 ret = sscanf(buf, "%i %i", ®, &val);
194 indio_dev->cached_reg_addr = reg;
197 indio_dev->cached_reg_addr = reg;
198 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
201 dev_err(indio_dev->dev.parent, "%s: write failed\n",
213 static const struct file_operations iio_debugfs_reg_fops = {
215 .read = iio_debugfs_read_reg,
216 .write = iio_debugfs_write_reg,
219 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
221 debugfs_remove_recursive(indio_dev->debugfs_dentry);
224 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
228 if (indio_dev->info->debugfs_reg_access == NULL)
231 if (!iio_debugfs_dentry)
234 indio_dev->debugfs_dentry =
235 debugfs_create_dir(dev_name(&indio_dev->dev),
237 if (indio_dev->debugfs_dentry == NULL) {
238 dev_warn(indio_dev->dev.parent,
239 "Failed to create debugfs directory\n");
243 d = debugfs_create_file("direct_reg_access", 0644,
244 indio_dev->debugfs_dentry,
245 indio_dev, &iio_debugfs_reg_fops);
247 iio_device_unregister_debugfs(indio_dev);
254 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
259 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
262 #endif /* CONFIG_DEBUG_FS */
264 static ssize_t iio_read_channel_ext_info(struct device *dev,
265 struct device_attribute *attr,
268 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
269 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
270 const struct iio_chan_spec_ext_info *ext_info;
272 ext_info = &this_attr->c->ext_info[this_attr->address];
274 return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
277 static ssize_t iio_write_channel_ext_info(struct device *dev,
278 struct device_attribute *attr,
282 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
283 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
284 const struct iio_chan_spec_ext_info *ext_info;
286 ext_info = &this_attr->c->ext_info[this_attr->address];
288 return ext_info->write(indio_dev, ext_info->private,
289 this_attr->c, buf, len);
292 static ssize_t iio_read_channel_info(struct device *dev,
293 struct device_attribute *attr,
296 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
297 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
299 bool scale_db = false;
300 int ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
301 &val, &val2, this_attr->address);
308 return sprintf(buf, "%d\n", val);
309 case IIO_VAL_INT_PLUS_MICRO_DB:
311 case IIO_VAL_INT_PLUS_MICRO:
313 return sprintf(buf, "-%d.%06u%s\n", val, -val2,
314 scale_db ? " dB" : "");
316 return sprintf(buf, "%d.%06u%s\n", val, val2,
317 scale_db ? " dB" : "");
318 case IIO_VAL_INT_PLUS_NANO:
320 return sprintf(buf, "-%d.%09u\n", val, -val2);
322 return sprintf(buf, "%d.%09u\n", val, val2);
328 static ssize_t iio_write_channel_info(struct device *dev,
329 struct device_attribute *attr,
333 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
334 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
335 int ret, integer = 0, fract = 0, fract_mult = 100000;
336 bool integer_part = true, negative = false;
338 /* Assumes decimal - precision based on number of digits */
339 if (!indio_dev->info->write_raw)
342 if (indio_dev->info->write_raw_get_fmt)
343 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
344 this_attr->c, this_attr->address)) {
345 case IIO_VAL_INT_PLUS_MICRO:
348 case IIO_VAL_INT_PLUS_NANO:
349 fract_mult = 100000000;
361 if ('0' <= *buf && *buf <= '9') {
363 integer = integer*10 + *buf - '0';
365 fract += fract_mult*(*buf - '0');
370 } else if (*buf == '\n') {
371 if (*(buf + 1) == '\0')
375 } else if (*buf == '.') {
376 integer_part = false;
389 ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
390 integer, fract, this_attr->address);
398 int __iio_device_attr_init(struct device_attribute *dev_attr,
400 struct iio_chan_spec const *chan,
401 ssize_t (*readfunc)(struct device *dev,
402 struct device_attribute *attr,
404 ssize_t (*writefunc)(struct device *dev,
405 struct device_attribute *attr,
411 char *name_format, *full_postfix;
412 sysfs_attr_init(&dev_attr->attr);
414 /* Build up postfix of <extend_name>_<modifier>_postfix */
415 if (chan->modified && !generic) {
416 if (chan->extend_name)
417 full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
418 iio_modifier_names[chan
423 full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
424 iio_modifier_names[chan
428 if (chan->extend_name == NULL)
429 full_postfix = kstrdup(postfix, GFP_KERNEL);
431 full_postfix = kasprintf(GFP_KERNEL,
436 if (full_postfix == NULL) {
441 if (chan->differential) { /* Differential can not have modifier */
444 = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
445 iio_direction[chan->output],
446 iio_chan_type_name_spec[chan->type],
447 iio_chan_type_name_spec[chan->type],
449 else if (chan->indexed)
451 = kasprintf(GFP_KERNEL, "%s_%s%d-%s%d_%s",
452 iio_direction[chan->output],
453 iio_chan_type_name_spec[chan->type],
455 iio_chan_type_name_spec[chan->type],
459 WARN_ON("Differential channels must be indexed\n");
461 goto error_free_full_postfix;
463 } else { /* Single ended */
466 = kasprintf(GFP_KERNEL, "%s_%s_%s",
467 iio_direction[chan->output],
468 iio_chan_type_name_spec[chan->type],
470 else if (chan->indexed)
472 = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
473 iio_direction[chan->output],
474 iio_chan_type_name_spec[chan->type],
479 = kasprintf(GFP_KERNEL, "%s_%s_%s",
480 iio_direction[chan->output],
481 iio_chan_type_name_spec[chan->type],
484 if (name_format == NULL) {
486 goto error_free_full_postfix;
488 dev_attr->attr.name = kasprintf(GFP_KERNEL,
492 if (dev_attr->attr.name == NULL) {
494 goto error_free_name_format;
498 dev_attr->attr.mode |= S_IRUGO;
499 dev_attr->show = readfunc;
503 dev_attr->attr.mode |= S_IWUSR;
504 dev_attr->store = writefunc;
511 error_free_name_format:
513 error_free_full_postfix:
519 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
521 kfree(dev_attr->attr.name);
524 int __iio_add_chan_devattr(const char *postfix,
525 struct iio_chan_spec const *chan,
526 ssize_t (*readfunc)(struct device *dev,
527 struct device_attribute *attr,
529 ssize_t (*writefunc)(struct device *dev,
530 struct device_attribute *attr,
536 struct list_head *attr_list)
539 struct iio_dev_attr *iio_attr, *t;
541 iio_attr = kzalloc(sizeof *iio_attr, GFP_KERNEL);
542 if (iio_attr == NULL) {
546 ret = __iio_device_attr_init(&iio_attr->dev_attr,
548 readfunc, writefunc, generic);
550 goto error_iio_dev_attr_free;
552 iio_attr->address = mask;
553 list_for_each_entry(t, attr_list, l)
554 if (strcmp(t->dev_attr.attr.name,
555 iio_attr->dev_attr.attr.name) == 0) {
557 dev_err(dev, "tried to double register : %s\n",
558 t->dev_attr.attr.name);
560 goto error_device_attr_deinit;
562 list_add(&iio_attr->l, attr_list);
566 error_device_attr_deinit:
567 __iio_device_attr_deinit(&iio_attr->dev_attr);
568 error_iio_dev_attr_free:
574 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
575 struct iio_chan_spec const *chan)
577 int ret, attrcount = 0;
579 const struct iio_chan_spec_ext_info *ext_info;
581 if (chan->channel < 0)
583 for_each_set_bit(i, &chan->info_mask, sizeof(long)*8) {
584 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i/2],
586 &iio_read_channel_info,
587 &iio_write_channel_info,
591 &indio_dev->channel_attr_list);
592 if (ret == -EBUSY && (i%2 == 0)) {
601 if (chan->ext_info) {
603 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
604 ret = __iio_add_chan_devattr(ext_info->name,
607 &iio_read_channel_ext_info : NULL,
609 &iio_write_channel_ext_info : NULL,
613 &indio_dev->channel_attr_list);
615 if (ret == -EBUSY && ext_info->shared)
630 static void iio_device_remove_and_free_read_attr(struct iio_dev *indio_dev,
631 struct iio_dev_attr *p)
633 kfree(p->dev_attr.attr.name);
637 static ssize_t iio_show_dev_name(struct device *dev,
638 struct device_attribute *attr,
641 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
642 return sprintf(buf, "%s\n", indio_dev->name);
645 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
647 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
649 int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
650 struct iio_dev_attr *p, *n;
651 struct attribute **attr;
653 /* First count elements in any existing group */
654 if (indio_dev->info->attrs) {
655 attr = indio_dev->info->attrs->attrs;
656 while (*attr++ != NULL)
659 attrcount = attrcount_orig;
661 * New channel registration method - relies on the fact a group does
662 * not need to be initialized if it is name is NULL.
664 INIT_LIST_HEAD(&indio_dev->channel_attr_list);
665 if (indio_dev->channels)
666 for (i = 0; i < indio_dev->num_channels; i++) {
667 ret = iio_device_add_channel_sysfs(indio_dev,
671 goto error_clear_attrs;
678 indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
679 sizeof(indio_dev->chan_attr_group.attrs[0]),
681 if (indio_dev->chan_attr_group.attrs == NULL) {
683 goto error_clear_attrs;
685 /* Copy across original attributes */
686 if (indio_dev->info->attrs)
687 memcpy(indio_dev->chan_attr_group.attrs,
688 indio_dev->info->attrs->attrs,
689 sizeof(indio_dev->chan_attr_group.attrs[0])
691 attrn = attrcount_orig;
692 /* Add all elements from the list. */
693 list_for_each_entry(p, &indio_dev->channel_attr_list, l)
694 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
696 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
698 indio_dev->groups[indio_dev->groupcounter++] =
699 &indio_dev->chan_attr_group;
704 list_for_each_entry_safe(p, n,
705 &indio_dev->channel_attr_list, l) {
707 iio_device_remove_and_free_read_attr(indio_dev, p);
713 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
716 struct iio_dev_attr *p, *n;
718 list_for_each_entry_safe(p, n, &indio_dev->channel_attr_list, l) {
720 iio_device_remove_and_free_read_attr(indio_dev, p);
722 kfree(indio_dev->chan_attr_group.attrs);
725 static void iio_dev_release(struct device *device)
727 struct iio_dev *indio_dev = dev_to_iio_dev(device);
728 cdev_del(&indio_dev->chrdev);
729 if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
730 iio_device_unregister_trigger_consumer(indio_dev);
731 iio_device_unregister_eventset(indio_dev);
732 iio_device_unregister_sysfs(indio_dev);
733 iio_device_unregister_debugfs(indio_dev);
736 static struct device_type iio_dev_type = {
737 .name = "iio_device",
738 .release = iio_dev_release,
741 struct iio_dev *iio_device_alloc(int sizeof_priv)
746 alloc_size = sizeof(struct iio_dev);
748 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
749 alloc_size += sizeof_priv;
751 /* ensure 32-byte alignment of whole construct ? */
752 alloc_size += IIO_ALIGN - 1;
754 dev = kzalloc(alloc_size, GFP_KERNEL);
757 dev->dev.groups = dev->groups;
758 dev->dev.type = &iio_dev_type;
759 dev->dev.bus = &iio_bus_type;
760 device_initialize(&dev->dev);
761 dev_set_drvdata(&dev->dev, (void *)dev);
762 mutex_init(&dev->mlock);
763 mutex_init(&dev->info_exist_lock);
765 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
767 /* cannot use a dev_err as the name isn't available */
768 printk(KERN_ERR "Failed to get id\n");
772 dev_set_name(&dev->dev, "iio:device%d", dev->id);
777 EXPORT_SYMBOL(iio_device_alloc);
779 void iio_device_free(struct iio_dev *dev)
782 ida_simple_remove(&iio_ida, dev->id);
786 EXPORT_SYMBOL(iio_device_free);
789 * iio_chrdev_open() - chrdev file open for buffer access and ioctls
791 static int iio_chrdev_open(struct inode *inode, struct file *filp)
793 struct iio_dev *indio_dev = container_of(inode->i_cdev,
794 struct iio_dev, chrdev);
796 if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
799 filp->private_data = indio_dev;
805 * iio_chrdev_release() - chrdev file close buffer access and ioctls
807 static int iio_chrdev_release(struct inode *inode, struct file *filp)
809 struct iio_dev *indio_dev = container_of(inode->i_cdev,
810 struct iio_dev, chrdev);
811 clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
815 /* Somewhat of a cross file organization violation - ioctls here are actually
817 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
819 struct iio_dev *indio_dev = filp->private_data;
820 int __user *ip = (int __user *)arg;
823 if (cmd == IIO_GET_EVENT_FD_IOCTL) {
824 fd = iio_event_getfd(indio_dev);
825 if (copy_to_user(ip, &fd, sizeof(fd)))
832 static const struct file_operations iio_buffer_fileops = {
833 .read = iio_buffer_read_first_n_outer_addr,
834 .release = iio_chrdev_release,
835 .open = iio_chrdev_open,
836 .poll = iio_buffer_poll_addr,
837 .owner = THIS_MODULE,
838 .llseek = noop_llseek,
839 .unlocked_ioctl = iio_ioctl,
840 .compat_ioctl = iio_ioctl,
843 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
845 int iio_device_register(struct iio_dev *indio_dev)
849 /* configure elements for the chrdev */
850 indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
852 ret = iio_device_register_debugfs(indio_dev);
854 dev_err(indio_dev->dev.parent,
855 "Failed to register debugfs interfaces\n");
858 ret = iio_device_register_sysfs(indio_dev);
860 dev_err(indio_dev->dev.parent,
861 "Failed to register sysfs interfaces\n");
862 goto error_unreg_debugfs;
864 ret = iio_device_register_eventset(indio_dev);
866 dev_err(indio_dev->dev.parent,
867 "Failed to register event set\n");
868 goto error_free_sysfs;
870 if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
871 iio_device_register_trigger_consumer(indio_dev);
873 if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
874 indio_dev->setup_ops == NULL)
875 indio_dev->setup_ops = &noop_ring_setup_ops;
877 ret = device_add(&indio_dev->dev);
879 goto error_unreg_eventset;
880 cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
881 indio_dev->chrdev.owner = indio_dev->info->driver_module;
882 ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
884 goto error_del_device;
888 device_del(&indio_dev->dev);
889 error_unreg_eventset:
890 iio_device_unregister_eventset(indio_dev);
892 iio_device_unregister_sysfs(indio_dev);
894 iio_device_unregister_debugfs(indio_dev);
898 EXPORT_SYMBOL(iio_device_register);
900 void iio_device_unregister(struct iio_dev *indio_dev)
902 mutex_lock(&indio_dev->info_exist_lock);
903 indio_dev->info = NULL;
904 mutex_unlock(&indio_dev->info_exist_lock);
905 device_unregister(&indio_dev->dev);
907 EXPORT_SYMBOL(iio_device_unregister);
908 subsys_initcall(iio_init);
909 module_exit(iio_exit);
911 MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
912 MODULE_DESCRIPTION("Industrial I/O core");
913 MODULE_LICENSE("GPL");