316 строки
7.1 KiB
C
316 строки
7.1 KiB
C
/*
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* IDT Interprise 79RC32434 watchdog driver
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*
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* Copyright (C) 2006, Ondrej Zajicek <santiago@crfreenet.org>
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* Copyright (C) 2008, Florian Fainelli <florian@openwrt.org>
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*
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* based on
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* SoftDog 0.05: A Software Watchdog Device
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*
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* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
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* All Rights Reserved.
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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/kernel.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/reboot.h>
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#include <linux/smp_lock.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/uaccess.h>
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#include <asm/bootinfo.h>
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#include <asm/time.h>
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#include <asm/mach-rc32434/integ.h>
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#define VERSION "0.4"
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static struct {
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unsigned long inuse;
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} rc32434_wdt_device;
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static struct integ __iomem *wdt_reg;
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static int expect_close;
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/* Board internal clock speed in Hz,
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* the watchdog timer ticks at. */
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extern unsigned int idt_cpu_freq;
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/* translate wtcompare value to seconds and vice versa */
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#define WTCOMP2SEC(x) (x / idt_cpu_freq)
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#define SEC2WTCOMP(x) (x * idt_cpu_freq)
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/* Use a default timeout of 20s. This should be
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* safe for CPU clock speeds up to 400MHz, as
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* ((2 ^ 32) - 1) / (400MHz / 2) = 21s. */
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#define WATCHDOG_TIMEOUT 20
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static int timeout = WATCHDOG_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="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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/* apply or and nand masks to data read from addr and write back */
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#define SET_BITS(addr, or, nand) \
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writel((readl(&addr) | or) & ~nand, &addr)
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static void rc32434_wdt_start(void)
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{
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u32 or, nand;
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/* zero the counter before enabling */
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writel(0, &wdt_reg->wtcount);
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/* don't generate a non-maskable interrupt,
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* do a warm reset instead */
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nand = 1 << RC32434_ERR_WNE;
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or = 1 << RC32434_ERR_WRE;
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/* reset the ERRCS timeout bit in case it's set */
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nand |= 1 << RC32434_ERR_WTO;
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SET_BITS(wdt_reg->errcs, or, nand);
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/* reset WTC timeout bit and enable WDT */
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nand = 1 << RC32434_WTC_TO;
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or = 1 << RC32434_WTC_EN;
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SET_BITS(wdt_reg->wtc, or, nand);
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}
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static void rc32434_wdt_stop(void)
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{
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/* Disable WDT */
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SET_BITS(wdt_reg->wtc, 0, 1 << RC32434_WTC_EN);
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}
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static int rc32434_wdt_set(int new_timeout)
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{
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int max_to = WTCOMP2SEC((u32)-1);
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if (new_timeout < 0 || new_timeout > max_to) {
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printk(KERN_ERR KBUILD_MODNAME
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": timeout value must be between 0 and %d",
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max_to);
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return -EINVAL;
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}
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timeout = new_timeout;
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writel(SEC2WTCOMP(timeout), &wdt_reg->wtcompare);
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return 0;
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}
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static void rc32434_wdt_ping(void)
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{
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writel(0, &wdt_reg->wtcount);
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}
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static int rc32434_wdt_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(0, &rc32434_wdt_device.inuse))
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return -EBUSY;
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if (nowayout)
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__module_get(THIS_MODULE);
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rc32434_wdt_start();
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rc32434_wdt_ping();
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return nonseekable_open(inode, file);
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}
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static int rc32434_wdt_release(struct inode *inode, struct file *file)
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{
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if (expect_close == 42) {
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rc32434_wdt_stop();
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printk(KERN_INFO KBUILD_MODNAME ": disabling watchdog timer\n");
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module_put(THIS_MODULE);
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} else {
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printk(KERN_CRIT KBUILD_MODNAME
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": device closed unexpectedly. WDT will not stop !\n");
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rc32434_wdt_ping();
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}
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clear_bit(0, &rc32434_wdt_device.inuse);
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return 0;
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}
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static ssize_t rc32434_wdt_write(struct file *file, const char *data,
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size_t len, loff_t *ppos)
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{
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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 = 42;
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}
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}
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rc32434_wdt_ping();
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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 long rc32434_wdt_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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void __user *argp = (void __user *)arg;
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int new_timeout;
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unsigned int value;
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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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.identity = "RC32434_WDT Watchdog",
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};
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switch (cmd) {
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case WDIOC_KEEPALIVE:
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rc32434_wdt_ping();
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break;
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case WDIOC_GETSTATUS:
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case WDIOC_GETBOOTSTATUS:
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value = 0;
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if (copy_to_user(argp, &value, sizeof(int)))
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return -EFAULT;
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break;
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case WDIOC_GETSUPPORT:
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if (copy_to_user(argp, &ident, sizeof(ident)))
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return -EFAULT;
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break;
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case WDIOC_SETOPTIONS:
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if (copy_from_user(&value, argp, sizeof(int)))
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return -EFAULT;
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switch (value) {
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case WDIOS_ENABLECARD:
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rc32434_wdt_start();
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break;
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case WDIOS_DISABLECARD:
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rc32434_wdt_stop();
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break;
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default:
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return -EINVAL;
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}
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break;
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case WDIOC_SETTIMEOUT:
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if (copy_from_user(&new_timeout, argp, sizeof(int)))
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return -EFAULT;
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if (rc32434_wdt_set(new_timeout))
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return -EINVAL;
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/* Fall through */
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case WDIOC_GETTIMEOUT:
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return copy_to_user(argp, &timeout, sizeof(int));
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default:
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return -ENOTTY;
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}
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return 0;
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}
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static struct file_operations rc32434_wdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = rc32434_wdt_write,
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.unlocked_ioctl = rc32434_wdt_ioctl,
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.open = rc32434_wdt_open,
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.release = rc32434_wdt_release,
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};
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static struct miscdevice rc32434_wdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &rc32434_wdt_fops,
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};
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static char banner[] __devinitdata = KERN_INFO KBUILD_MODNAME
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": Watchdog Timer version " VERSION ", timer margin: %d sec\n";
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static int __devinit rc32434_wdt_probe(struct platform_device *pdev)
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{
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int ret;
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struct resource *r;
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r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rb532_wdt_res");
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if (!r) {
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printk(KERN_ERR KBUILD_MODNAME
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"failed to retrieve resources\n");
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return -ENODEV;
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}
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wdt_reg = ioremap_nocache(r->start, r->end - r->start);
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if (!wdt_reg) {
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printk(KERN_ERR KBUILD_MODNAME
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"failed to remap I/O resources\n");
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return -ENXIO;
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}
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ret = misc_register(&rc32434_wdt_miscdev);
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if (ret < 0) {
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printk(KERN_ERR KBUILD_MODNAME
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"failed to register watchdog device\n");
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goto unmap;
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}
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printk(banner, timeout);
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return 0;
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unmap:
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iounmap(wdt_reg);
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return ret;
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}
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static int __devexit rc32434_wdt_remove(struct platform_device *pdev)
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{
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misc_deregister(&rc32434_wdt_miscdev);
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iounmap(wdt_reg);
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return 0;
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}
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static struct platform_driver rc32434_wdt = {
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.probe = rc32434_wdt_probe,
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.remove = __devexit_p(rc32434_wdt_remove),
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.driver = {
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.name = "rc32434_wdt",
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}
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};
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static int __init rc32434_wdt_init(void)
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{
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return platform_driver_register(&rc32434_wdt);
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}
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static void __exit rc32434_wdt_exit(void)
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{
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platform_driver_unregister(&rc32434_wdt);
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}
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module_init(rc32434_wdt_init);
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module_exit(rc32434_wdt_exit);
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MODULE_AUTHOR("Ondrej Zajicek <santiago@crfreenet.org>,"
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"Florian Fainelli <florian@openwrt.org>");
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MODULE_DESCRIPTION("Driver for the IDT RC32434 SoC watchdog");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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