mirror of
git://projects.qi-hardware.com/openwrt-xburst.git
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27e94101de
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@27162 3c298f89-4303-0410-b956-a3cf2f4a3e73
204 lines
4.4 KiB
C
204 lines
4.4 KiB
C
/*
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* ADM5120_WDT 0.01: Infineon ADM5120 SoC watchdog driver
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* Copyright (c) Ondrej Zajicek <santiago@crfreenet.org>, 2007
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*
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* based on
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*
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* RC32434_WDT 0.01: IDT Interprise 79RC32434 watchdog driver
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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*/
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/fs.h>
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#include <linux/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/irq.h>
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#include <asm/bootinfo.h>
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#include <asm/mach-adm5120/adm5120_info.h>
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#include <asm/mach-adm5120/adm5120_defs.h>
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#include <asm/mach-adm5120/adm5120_switch.h>
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#define DEFAULT_TIMEOUT 15 /* (secs) Default is 15 seconds */
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#define MAX_TIMEOUT 327
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/* Max is 327 seconds, counter is 15-bit integer, step is 10 ms */
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#define NAME "adm5120_wdt"
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#define VERSION "0.1"
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static int expect_close;
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static int access;
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static unsigned int timeout = DEFAULT_TIMEOUT;
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static int nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, int, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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MODULE_LICENSE("GPL");
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static inline void wdt_set_timeout(void)
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{
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u32 val = (1 << 31) | (((timeout * 100) & 0x7FFF) << 16);
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SW_WRITE_REG(SWITCH_REG_WDOG0, val);
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}
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/*
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It looks like WDOG0-register-write don't modify counter,
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but WDOG0-register-read resets counter.
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*/
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static inline void wdt_reset_counter(void)
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{
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SW_READ_REG(SWITCH_REG_WDOG0);
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}
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static inline void wdt_disable(void)
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{
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SW_WRITE_REG(SWITCH_REG_WDOG0, 0x7FFF0000);
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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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/* Allow only one person to hold it open */
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if (access)
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return -EBUSY;
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if (nowayout)
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__module_get(THIS_MODULE);
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/* Activate timer */
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wdt_reset_counter();
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wdt_set_timeout();
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printk(KERN_INFO NAME ": enabling watchdog timer\n");
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access = 1;
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return 0;
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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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/*
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* Shut off the timer.
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* Lock it in if it's a module and we set nowayout
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*/
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if (expect_close && (nowayout == 0)) {
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wdt_disable();
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printk(KERN_INFO NAME ": disabling watchdog timer\n");
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module_put(THIS_MODULE);
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} else
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printk(KERN_CRIT NAME ": device closed unexpectedly. WDT will not stop!\n");
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access = 0;
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return 0;
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}
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static ssize_t wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
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{
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/* Refresh the timer. */
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if (len) {
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if (!nowayout) {
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size_t i;
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/* In case it was set long ago */
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expect_close = 0;
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for (i = 0; i != len; i++) {
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char c;
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if (get_user(c, data + i))
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return -EFAULT;
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if (c == 'V')
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expect_close = 1;
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}
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}
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wdt_reset_counter();
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return len;
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}
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return 0;
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}
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static int wdt_ioctl(struct inode *inode, struct file *file,
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unsigned int cmd, unsigned long arg)
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{
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int new_timeout;
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static struct watchdog_info ident = {
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.options = WDIOF_SETTIMEOUT |
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WDIOF_KEEPALIVEPING |
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WDIOF_MAGICCLOSE,
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.firmware_version = 0,
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.identity = "ADM5120_WDT Watchdog",
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};
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switch (cmd) {
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default:
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return -ENOTTY;
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case WDIOC_GETSUPPORT:
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if (copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident)))
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return -EFAULT;
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return 0;
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case WDIOC_GETSTATUS:
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case WDIOC_GETBOOTSTATUS:
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return put_user(0, (int *)arg);
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case WDIOC_KEEPALIVE:
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wdt_reset_counter();
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return 0;
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case WDIOC_SETTIMEOUT:
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if (get_user(new_timeout, (int *)arg))
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return -EFAULT;
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if (new_timeout < 1)
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return -EINVAL;
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if (new_timeout > MAX_TIMEOUT)
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return -EINVAL;
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timeout = new_timeout;
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wdt_set_timeout();
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/* Fall */
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case WDIOC_GETTIMEOUT:
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return put_user(timeout, (int *)arg);
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}
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}
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static const 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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.ioctl = wdt_ioctl,
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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 char banner[] __initdata = KERN_INFO NAME ": Watchdog Timer version " VERSION "\n";
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static int __init watchdog_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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return ret;
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wdt_disable();
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printk(banner);
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return 0;
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}
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static void __exit watchdog_exit(void)
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{
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misc_deregister(&wdt_miscdev);
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}
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module_init(watchdog_init);
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module_exit(watchdog_exit);
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