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/*
* arch/arm/mach-tegra/nvdumper.c
*
* Copyright (C) 2011 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/errno.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/reboot.h>
#include "board.h"
#define NVDUMPER_CLEAN 0xf000caf3U
#define NVDUMPER_DIRTY 0xdeadbeefU
static uint32_t *nvdumper_ptr;
static int get_dirty_state(void)
{
uint32_t val;
val = ioread32(nvdumper_ptr);
if (val == NVDUMPER_DIRTY)
return 1;
else if (val == NVDUMPER_CLEAN)
return 0;
else
return -1;
}
static void set_dirty_state(int dirty)
{
if (dirty)
iowrite32(NVDUMPER_DIRTY, nvdumper_ptr);
else
iowrite32(NVDUMPER_CLEAN, nvdumper_ptr);
}
static int nvdumper_reboot_cb(struct notifier_block *nb,
unsigned long event, void *unused)
{
printk(KERN_INFO "nvdumper: rebooting cleanly.\n");
set_dirty_state(0);
return NOTIFY_DONE;
}
struct notifier_block nvdumper_reboot_notifier = {
.notifier_call = nvdumper_reboot_cb,
};
static int __init nvdumper_init(void)
{
int ret, dirty;
if (!nvdumper_reserved) {
printk(KERN_INFO "nvdumper: not configured\n");
return -ENOTSUPP;
}
nvdumper_ptr = ioremap_nocache(nvdumper_reserved,
NVDUMPER_RESERVED_SIZE);
if (!nvdumper_ptr) {
printk(KERN_INFO "nvdumper: failed to ioremap memory "
"at 0x%08lx\n", nvdumper_reserved);
return -EIO;
}
ret = register_reboot_notifier(&nvdumper_reboot_notifier);
if (ret)
return ret;
dirty = get_dirty_state();
switch (dirty) {
case 0:
printk(KERN_INFO "nvdumper: last reboot was clean\n");
break;
case 1:
printk(KERN_INFO "nvdumper: last reboot was dirty\n");
break;
default:
printk(KERN_INFO "nvdumper: last reboot was unknown\n");
break;
}
set_dirty_state(1);
return 0;
}
static void __exit nvdumper_exit(void)
{
unregister_reboot_notifier(&nvdumper_reboot_notifier);
set_dirty_state(0);
iounmap(nvdumper_ptr);
}
module_init(nvdumper_init);
module_exit(nvdumper_exit);
MODULE_LICENSE("GPL");
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