315 lines
7 KiB
C
315 lines
7 KiB
C
/*
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* Broadcom BCM63xx SoC watchdog driver
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*
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* Copyright (C) 2007, Miguel Gaio <miguel.gaio@efixo.com>
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* Copyright (C) 2008, Florian Fainelli <florian@openwrt.org>
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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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#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 <linux/timer.h>
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#include <bcm63xx_cpu.h>
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#include <bcm63xx_io.h>
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#include <bcm63xx_regs.h>
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#define PFX KBUILD_MODNAME
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#define WDT_HZ 50000000 /* Fclk */
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#define WDT_INTERVAL (40) /* in seconds */
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static struct {
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void __iomem *regs;
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struct completion stop;
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int running;
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struct timer_list timer;
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int queue;
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int default_ticks;
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unsigned long inuse;
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} bcm63xx_wdt_device;
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static int ticks = 100 * WDT_HZ;
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static int expect_close;
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static int 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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static void bcm63xx_wdt_toggle(void)
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{
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bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
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bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
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}
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static void bcm63xx_wdt_start(void)
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{
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if (!bcm63xx_wdt_device.inuse) {
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bcm63xx_wdt_toggle();
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mod_timer(&bcm63xx_wdt_device.timer, jiffies + WDT_INTERVAL);
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}
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bcm63xx_wdt_device.running++;
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}
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static void bcm63xx_wdt_stop(void)
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{
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if (bcm63xx_wdt_device.running) {
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bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
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bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
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bcm63xx_wdt_device.running = 0;
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}
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}
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static void bcm63xx_wdt_set(int new_timeout)
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{
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new_timeout *= WDT_HZ;
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bcm_writel(new_timeout, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
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}
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static void bcm63xx_wdt_reset(void)
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{
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ticks = bcm63xx_wdt_device.default_ticks;
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}
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static void bcm63xx_wdt_update(unsigned long unused)
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{
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if (bcm63xx_wdt_device.running)
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ticks--;
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bcm63xx_wdt_toggle();
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if (bcm63xx_wdt_device.queue && ticks)
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mod_timer(&bcm63xx_wdt_device.timer,
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jiffies + WDT_INTERVAL);
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else
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complete(&bcm63xx_wdt_device.stop);
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}
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static int bcm63xx_wdt_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(0, &bcm63xx_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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return nonseekable_open(inode, file);
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}
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static int bcm63xx_wdt_release(struct inode *inode, struct file *file)
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{
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if (expect_close && nowayout == 0) {
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bcm63xx_wdt_stop();
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printk(KERN_INFO PFX ": disabling watchdog timer\n");
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module_put(THIS_MODULE);
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} else
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printk(KERN_CRIT PFX
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": device closed unexpectedly. WDT will not stop !\n");
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clear_bit(0, &bcm63xx_wdt_device.inuse);
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return 0;
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}
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static ssize_t bcm63xx_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 = 1;
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}
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}
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bcm63xx_wdt_update(0);
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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 bcm63xx_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 = "BCM63xx Watchdog",
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};
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switch (cmd) {
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case WDIOC_KEEPALIVE:
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bcm63xx_wdt_reset();
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break;
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case WDIOC_GETSTATUS:
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case WDIOC_GETBOOTSTATUS:
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value = bcm_readl(bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
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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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bcm63xx_wdt_start();
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break;
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case WDIOS_DISABLECARD:
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bcm63xx_wdt_stop();
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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 (new_timeout < 5)
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return -EINVAL;
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if (new_timeout > 40)
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return -EINVAL;
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bcm63xx_wdt_set(new_timeout);
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bcm63xx_wdt_toggle();
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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 bcm63xx_wdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = bcm63xx_wdt_write,
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.unlocked_ioctl = bcm63xx_wdt_ioctl,
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.open = bcm63xx_wdt_open,
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.release = bcm63xx_wdt_release,
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};
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static struct miscdevice bcm63xx_wdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &bcm63xx_wdt_fops,
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};
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static int bcm63xx_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(pdev, IORESOURCE_MEM, 0);
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if (!r) {
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printk(KERN_ERR PFX
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"failed to retrieve resources\n");
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return -ENODEV;
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}
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bcm63xx_wdt_device.regs = ioremap_nocache(r->start, r->end - r->start);
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if (!bcm63xx_wdt_device.regs) {
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printk(KERN_ERR PFX
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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(&bcm63xx_wdt_miscdev);
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if (ret < 0) {
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printk(KERN_ERR PFX
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"failed to register watchdog device\n");
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goto unmap;
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}
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init_completion(&bcm63xx_wdt_device.stop);
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bcm63xx_wdt_device.queue = 0;
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clear_bit(0, &bcm63xx_wdt_device.inuse);
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setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_wdt_update, 0L);
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bcm63xx_wdt_device.default_ticks = ticks;
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bcm63xx_wdt_set(ticks);
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bcm63xx_wdt_start();
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printk(KERN_INFO PFX " started, timer margin: %d sec\n", WDT_INTERVAL);
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return 0;
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unmap:
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iounmap(bcm63xx_wdt_device.regs);
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return ret;
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}
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static int bcm63xx_wdt_remove(struct platform_device *pdev)
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{
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if (bcm63xx_wdt_device.queue) {
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bcm63xx_wdt_device.queue = 0;
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wait_for_completion(&bcm63xx_wdt_device.stop);
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}
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misc_deregister(&bcm63xx_wdt_miscdev);
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iounmap(bcm63xx_wdt_device.regs);
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return 0;
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}
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static struct platform_driver bcm63xx_wdt = {
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.probe = bcm63xx_wdt_probe,
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.remove = bcm63xx_wdt_remove,
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.driver = {
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.name = "bcm63xx-wdt",
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}
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};
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static int __init bcm63xx_wdt_init(void)
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{
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return platform_driver_register(&bcm63xx_wdt);
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}
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static void __exit bcm63xx_wdt_exit(void)
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{
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platform_driver_unregister(&bcm63xx_wdt);
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}
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module_init(bcm63xx_wdt_init);
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module_exit(bcm63xx_wdt_exit);
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MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
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MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
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MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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MODULE_ALIAS("platform:bcm63xx-wdt");
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