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/*
* arch/arch/mach-tegra/timerinfo.c
*
* Copyright (C) 2012 NVIDIA Corporation.
*
* Author:
* Jon Mayo <jmayo@nvidia.com>
*
* Copyright (C) 2012 NVIDIA Corporation.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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.
*
*/
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/platform_device.h>
#include <linux/miscdevice.h>
#include <mach/iomap.h>
#include "timer.h"
static int timerinfo_dev_mmap(struct file *file, struct vm_area_struct *vma);
static const struct file_operations timerinfo_dev_fops = {
.owner = THIS_MODULE,
.open = nonseekable_open,
.mmap = timerinfo_dev_mmap,
.llseek = noop_llseek,
};
static struct miscdevice timerinfo_dev = {
.minor = MISC_DYNAMIC_MINOR,
.name = "timerinfo",
.fops = &timerinfo_dev_fops,
};
static int timerinfo_dev_mmap(struct file *file, struct vm_area_struct *vma)
{
/* start at first page containing TIMERUS_CNTR_1US */
phys_addr_t addr = TEGRA_TMR1_BASE;
if (vma->vm_end - vma->vm_start != PAGE_SIZE)
return -EINVAL;
if (vma->vm_flags & VM_WRITE)
return -EPERM;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
if (remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT, PAGE_SIZE,
vma->vm_page_prot)) {
pr_err("%s:remap_pfn_range failed\n", timerinfo_dev.name);
return -EAGAIN;
}
return 0;
}
static int __init timerinfo_dev_init(void)
{
return misc_register(&timerinfo_dev);
}
module_init(timerinfo_dev_init);
MODULE_LICENSE("GPL");
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