113 lines
2.3 KiB
C
113 lines
2.3 KiB
C
#include <linux/autoconf.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/fs.h>
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#include <linux/jiffies.h>
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#include <linux/timer.h>
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#include <asm/io.h>
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#include <asm/uaccess.h>
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#include <asm/system.h>
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#include <asm/bootinfo.h>
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extern unsigned long mips_machtype;
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static unsigned long wdt_is_open;
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static struct timer_list wdt_timer;
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static void wdt_merlot_refresh(void)
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{
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volatile __u32 *wdt;
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switch (mips_machtype) {
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case MACH_ARUBA_AP70:
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wdt = (__u32 *) 0xb8030034;
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*wdt = 0x10000000;
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break;
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default:
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wdt = (__u32 *) 0xbc00300c;
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*wdt = 0x40000000;
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break;
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}
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}
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static void wdt_merlot_timer_fn(unsigned long data)
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{
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wdt_merlot_refresh();
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if (!test_bit(1, &wdt_is_open))
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mod_timer(&wdt_timer, jiffies + HZ);
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}
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static int wdt_merlot_setup_timer(void)
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{
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init_timer(&wdt_timer);
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wdt_timer.function = wdt_merlot_timer_fn;
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wdt_timer.data = 0;
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wdt_timer.expires = jiffies + HZ;
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add_timer(&wdt_timer);
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return 0;
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}
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static int wdt_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(0, &wdt_is_open))
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return -EBUSY;
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set_bit(1, &wdt_is_open);
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return nonseekable_open(inode, file);
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}
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static ssize_t wdt_write(struct file *file, const char __user * buf, size_t count, loff_t * ppos)
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{
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if (count) /* something was written */
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wdt_merlot_refresh();
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return count;
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}
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static int wdt_release(struct inode *inode, struct file *file)
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{
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clear_bit(0, &wdt_is_open);
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return 0;
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}
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static struct file_operations wdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = wdt_write,
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.open = wdt_open,
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.release = wdt_release,
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};
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static struct miscdevice wdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &wdt_fops,
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};
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static void __exit wdt_exit(void)
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{
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misc_deregister(&wdt_miscdev);
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}
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static int __init wdt_init(void)
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{
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int ret;
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ret = misc_register(&wdt_miscdev);
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if (ret) {
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printk(KERN_ERR
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"wdt: cannot register miscdev on minor=%d (err=%d)\n",
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WATCHDOG_MINOR, ret);
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misc_deregister(&wdt_miscdev);
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goto out;
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}
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printk("wdt: registered with refresh\n");
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wdt_merlot_refresh();
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wdt_merlot_setup_timer();
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out:
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return ret;
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}
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module_init(wdt_init);
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module_exit(wdt_exit);
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