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/*
* Secure Mode Input interface to remoteproc driver
*
* Copyright (C) 2011 Texas Instruments. All rights reserved.
*
* Authors: Suman Anna <s-anna@ti.com>
*
* 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.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/miscdevice.h>
#include <linux/cdev.h>
#include <linux/uaccess.h>
#include <linux/file.h>
#include <linux/poll.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/remoteproc.h>
#define RPROC_USER_NAME "rproc_user"
#define RPROC_USER_DEVICES 1
static DEFINE_MUTEX(rproc_user_mutex);
struct rproc_user_device {
struct miscdevice mdev;
};
static struct rproc_user_device *ipu_device;
static char *rproc_user_name = RPROC_USER_NAME;
static unsigned secure_cnt;
static int rproc_user_open(struct inode *inode, struct file *filp)
{
filp->private_data = NULL;
return 0;
}
static int rproc_user_release(struct inode *inode, struct file *filp)
{
int ret = 0;
if (filp->private_data) {
mutex_lock(&rproc_user_mutex);
if (!--secure_cnt)
ret = rproc_set_secure("ipu", false);
mutex_unlock(&rproc_user_mutex);
if (ret)
pr_err("rproc normal start failed 0x%x, urghh!!", ret);
}
return ret;
}
static ssize_t rproc_user_read(struct file *filp, char __user *ubuf,
size_t len, loff_t *offp)
{
u8 enable;
int ret = 1;
if (len != 1)
return -EINVAL;
if (mutex_lock_interruptible(&rproc_user_mutex))
return -EINTR;
enable = secure_cnt ? 1 : 0;
if (copy_to_user((void *)ubuf, &enable, sizeof(enable)))
ret = -EFAULT;
mutex_unlock(&rproc_user_mutex);
return ret;
}
static ssize_t rproc_user_write(struct file *filp, const char __user *ubuf,
size_t len, loff_t *offp)
{
int ret = 0;
u8 enable;
if (len != 1)
return -EINVAL;
if (copy_from_user(&enable, (char __user *) ubuf, sizeof(enable)))
return -EFAULT;
if (mutex_lock_interruptible(&rproc_user_mutex))
return -EINTR;
enable = enable ? 1 : 0;
if (enable == (int)filp->private_data) {
ret = -EINVAL;
goto out;
}
switch (enable) {
case 1:
if (!secure_cnt++)
ret = rproc_set_secure("ipu", true);
if (!ret) {
filp->private_data = (void *)1;
goto out;
}
/* fall through in case of failure */
pr_err("rproc secure start failed, 0x%x\n", ret);
case 0:
if (!--secure_cnt)
ret = rproc_set_secure("ipu", false);
if (ret)
pr_err("rproc normal start failed 0x%x, urghh!!", ret);
else
filp->private_data = (void *)0;
}
if (enable != (int)filp->private_data)
ret = -EACCES;
out:
mutex_unlock(&rproc_user_mutex);
return ret ? ret : 1;
}
static const struct file_operations rproc_user_fops = {
.owner = THIS_MODULE,
.open = rproc_user_open,
.release = rproc_user_release,
.read = rproc_user_read,
.write = rproc_user_write,
};
static int __init rproc_user_init(void)
{
int ret;
ipu_device = kzalloc(sizeof(struct rproc_user_device), GFP_KERNEL);
if (!ipu_device) {
pr_err("%s: memory allocation failed for ipu_device\n",
__func__);
ret = -ENOMEM;
goto exit;
}
ipu_device->mdev.minor = MISC_DYNAMIC_MINOR;
ipu_device->mdev.name = rproc_user_name;
ipu_device->mdev.fops = &rproc_user_fops;
ipu_device->mdev.parent = NULL;
ret = misc_register(&ipu_device->mdev);
if (ret) {
pr_err("rproc_user_init: failed to register rproc_user misc "
"device\n");
goto misc_fail;
}
return ret;
misc_fail:
kfree(ipu_device);
exit:
return ret;
}
module_init(rproc_user_init);
static void __exit rproc_user_exit(void)
{
misc_deregister(&ipu_device->mdev);
kfree(ipu_device);
}
module_exit(rproc_user_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("RemoteProc Secure Mode Interface Driver");
MODULE_AUTHOR("Suman Anna");
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