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/*
* FRAM driver for MIMC200 board
*
* Copyright 2008 Mark Jackson <mpfj@mimc.co.uk>
*
* This module adds *very* simply support for the system's FRAM device.
* At the moment, this is hard-coded to the MIMC200 platform, and only
* supports mmap().
*/
#define FRAM_VERSION "1.0"
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/mm.h>
#include <linux/io.h>
#define FRAM_BASE 0xac000000
#define FRAM_SIZE 0x20000
/*
* The are the file operation function for user access to /dev/fram
*/
static int fram_mmap(struct file *filp, struct vm_area_struct *vma)
{
int ret;
ret = remap_pfn_range(vma,
vma->vm_start,
virt_to_phys((void *)((unsigned long)FRAM_BASE)) >> PAGE_SHIFT,
vma->vm_end-vma->vm_start,
PAGE_SHARED);
if (ret != 0)
return -EAGAIN;
return 0;
}
static const struct file_operations fram_fops = {
.owner = THIS_MODULE,
.mmap = fram_mmap,
.llseek = noop_llseek,
};
#define FRAM_MINOR 0
static struct miscdevice fram_dev = {
FRAM_MINOR,
"fram",
&fram_fops
};
static int __init
fram_init(void)
{
int ret;
ret = misc_register(&fram_dev);
if (ret) {
printk(KERN_ERR "fram: can't misc_register on minor=%d\n",
FRAM_MINOR);
return ret;
}
printk(KERN_INFO "FRAM memory driver v" FRAM_VERSION "\n");
return 0;
}
static void __exit
fram_cleanup_module(void)
{
misc_deregister(&fram_dev);
}
module_init(fram_init);
module_exit(fram_cleanup_module);
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(FRAM_MINOR);
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