path: root/drivers/iio/industrialio-core.c

/* The industrial I/O core
 *
 * Copyright (c) 2008 Jonathan Cameron
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * Based on elements of hwmon and input subsystems.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/idr.h>
#include <linux/kdev_t.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/cdev.h>
#include <linux/slab.h>
#include <linux/anon_inodes.h>
#include <linux/debugfs.h>
#include <linux/iio/iio.h>
#include "iio_core.h"
#include "iio_core_trigger.h"
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>

/* IDA to assign each registered device a unique id*/
static DEFINE_IDA(iio_ida);

static dev_t iio_devt;

#define IIO_DEV_MAX 256
struct bus_type iio_bus_type = {
	.name = "iio",
};
EXPORT_SYMBOL(iio_bus_type);

static struct dentry *iio_debugfs_dentry;

static const char * const iio_direction[] = {
	[0] = "in",
	[1] = "out",
};

static const char * const iio_chan_type_name_spec[] = {
	[IIO_VOLTAGE] = "voltage",
	[IIO_CURRENT] = "current",
	[IIO_POWER] = "power",
	[IIO_ACCEL] = "accel",
	[IIO_ANGL_VEL] = "anglvel",
	[IIO_MAGN] = "magn",
	[IIO_LIGHT] = "illuminance",
	[IIO_INTENSITY] = "intensity",
	[IIO_PROXIMITY] = "proximity",
	[IIO_TEMP] = "temp",
	[IIO_INCLI] = "incli",
	[IIO_ROT] = "rot",
	[IIO_ANGL] = "angl",
	[IIO_TIMESTAMP] = "timestamp",
	[IIO_CAPACITANCE] = "capacitance",
	[IIO_ALTVOLTAGE] = "altvoltage",
};

static const char * const iio_modifier_names[] = {
	[IIO_MOD_X] = "x",
	[IIO_MOD_Y] = "y",
	[IIO_MOD_Z] = "z",
	[IIO_MOD_LIGHT_BOTH] = "both",
	[IIO_MOD_LIGHT_IR] = "ir",
};

/* relies on pairs of these shared then separate */
static const char * const iio_chan_info_postfix[] = {
	[IIO_CHAN_INFO_RAW] = "raw",
	[IIO_CHAN_INFO_PROCESSED] = "input",
	[IIO_CHAN_INFO_SCALE] = "scale",
	[IIO_CHAN_INFO_OFFSET] = "offset",
	[IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
	[IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
	[IIO_CHAN_INFO_PEAK] = "peak_raw",
	[IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
	[IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
	[IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
	[IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
	= "filter_low_pass_3db_frequency",
	[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
	[IIO_CHAN_INFO_FREQUENCY] = "frequency",
	[IIO_CHAN_INFO_PHASE] = "phase",
};

const struct iio_chan_spec
*iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
{
	int i;

	for (i = 0; i < indio_dev->num_channels; i++)
		if (indio_dev->channels[i].scan_index == si)
			return &indio_dev->channels[i];
	return NULL;
}

/* This turns up an awful lot */
ssize_t iio_read_const_attr(struct device *dev,
			    struct device_attribute *attr,
			    char *buf)
{
	return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
}
EXPORT_SYMBOL(iio_read_const_attr);

static int __init iio_init(void)
{
	int ret;

	/* Register sysfs bus */
	ret  = bus_register(&iio_bus_type);
	if (ret < 0) {
		printk(KERN_ERR
		       "%s could not register bus type\n",
			__FILE__);
		goto error_nothing;
	}

	ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
	if (ret < 0) {
		printk(KERN_ERR "%s: failed to allocate char dev region\n",
		       __FILE__);
		goto error_unregister_bus_type;
	}

	iio_debugfs_dentry = debugfs_create_dir("iio", NULL);

	return 0;

error_unregister_bus_type:
	bus_unregister(&iio_bus_type);
error_nothing:
	return ret;
}

static void __exit iio_exit(void)
{
	if (iio_devt)
		unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
	bus_unregister(&iio_bus_type);
	debugfs_remove(iio_debugfs_dentry);
}

#if defined(CONFIG_DEBUG_FS)
static int iio_debugfs_open(struct inode *inode, struct file *file)
{
	if (inode->i_private)
		file->private_data = inode->i_private;

	return 0;
}

static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
			      size_t count, loff_t *ppos)
{
	struct iio_dev *indio_dev = file->private_data;