318 lines
7.0 KiB
C
318 lines
7.0 KiB
C
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/*
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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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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/bitops.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/miscdevice.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/types.h>
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#include <linux/uaccess.h>
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#include <linux/watchdog.h>
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#include <linux/timer.h>
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#include <linux/jiffies.h>
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#include <linux/interrupt.h>
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#include <linux/ptrace.h>
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#include <linux/resource.h>
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#include <linux/platform_device.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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#include <bcm63xx_timer.h>
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#define PFX KBUILD_MODNAME
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#define WDT_HZ 50000000 /* Fclk */
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#define WDT_DEFAULT_TIME 30 /* seconds */
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#define WDT_MAX_TIME 256 /* seconds */
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static struct {
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void __iomem *regs;
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struct timer_list timer;
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unsigned long inuse;
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atomic_t ticks;
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} bcm63xx_wdt_device;
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static int expect_close;
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static int wdt_time = WDT_DEFAULT_TIME;
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static bool nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, bool, 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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/* HW functions */
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static void bcm63xx_wdt_hw_start(void)
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{
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bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
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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_hw_stop(void)
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{
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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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}
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static void bcm63xx_wdt_isr(void *data)
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{
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struct pt_regs *regs = get_irq_regs();
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die(PFX " fire", regs);
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}
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static void bcm63xx_timer_tick(unsigned long unused)
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{
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if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) {
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bcm63xx_wdt_hw_start();
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mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ);
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} else
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pr_crit("watchdog will restart system\n");
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}
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static void bcm63xx_wdt_pet(void)
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{
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atomic_set(&bcm63xx_wdt_device.ticks, wdt_time);
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}
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static void bcm63xx_wdt_start(void)
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{
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bcm63xx_wdt_pet();
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bcm63xx_timer_tick(0);
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}
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static void bcm63xx_wdt_pause(void)
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{
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del_timer_sync(&bcm63xx_wdt_device.timer);
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bcm63xx_wdt_hw_stop();
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}
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static int bcm63xx_wdt_settimeout(int new_time)
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{
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if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
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return -EINVAL;
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wdt_time = new_time;
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return 0;
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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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bcm63xx_wdt_start();
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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 == 42)
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bcm63xx_wdt_pause();
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else {
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pr_crit("Unexpected close, not stopping watchdog!\n");
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bcm63xx_wdt_start();
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}
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clear_bit(0, &bcm63xx_wdt_device.inuse);
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expect_close = 0;
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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 = 42;
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}
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}
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bcm63xx_wdt_pet();
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}
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return len;
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}
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static struct watchdog_info bcm63xx_wdt_info = {
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.identity = PFX,
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.options = WDIOF_SETTIMEOUT |
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WDIOF_KEEPALIVEPING |
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WDIOF_MAGICCLOSE,
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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 __user *p = argp;
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int new_value, retval = -EINVAL;
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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return copy_to_user(argp, &bcm63xx_wdt_info,
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sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0;
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case WDIOC_GETSTATUS:
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case WDIOC_GETBOOTSTATUS:
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return put_user(0, p);
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case WDIOC_SETOPTIONS:
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if (get_user(new_value, p))
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return -EFAULT;
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if (new_value & WDIOS_DISABLECARD) {
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bcm63xx_wdt_pause();
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retval = 0;
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}
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if (new_value & WDIOS_ENABLECARD) {
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bcm63xx_wdt_start();
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retval = 0;
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}
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return retval;
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case WDIOC_KEEPALIVE:
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bcm63xx_wdt_pet();
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return 0;
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case WDIOC_SETTIMEOUT:
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if (get_user(new_value, p))
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return -EFAULT;
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if (bcm63xx_wdt_settimeout(new_value))
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return -EINVAL;
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bcm63xx_wdt_pet();
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case WDIOC_GETTIMEOUT:
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return put_user(wdt_time, p);
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default:
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return -ENOTTY;
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}
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}
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static const 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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setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0L);
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r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!r) {
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dev_err(&pdev->dev, "failed to get resources\n");
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return -ENODEV;
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}
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bcm63xx_wdt_device.regs = devm_ioremap_nocache(&pdev->dev, r->start,
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resource_size(r));
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if (!bcm63xx_wdt_device.regs) {
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dev_err(&pdev->dev, "failed to remap I/O resources\n");
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return -ENXIO;
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}
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ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL);
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if (ret < 0) {
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dev_err(&pdev->dev, "failed to register wdt timer isr\n");
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return ret;
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}
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if (bcm63xx_wdt_settimeout(wdt_time)) {
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bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME);
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dev_info(&pdev->dev,
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": wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
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wdt_time);
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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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dev_err(&pdev->dev, "failed to register watchdog device\n");
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goto unregister_timer;
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}
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dev_info(&pdev->dev, " started, timer margin: %d sec\n",
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WDT_DEFAULT_TIME);
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return 0;
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unregister_timer:
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bcm63xx_timer_unregister(TIMER_WDT_ID);
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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 (!nowayout)
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bcm63xx_wdt_pause();
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misc_deregister(&bcm63xx_wdt_miscdev);
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bcm63xx_timer_unregister(TIMER_WDT_ID);
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return 0;
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}
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static void bcm63xx_wdt_shutdown(struct platform_device *pdev)
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{
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bcm63xx_wdt_pause();
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}
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static struct platform_driver bcm63xx_wdt_driver = {
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.probe = bcm63xx_wdt_probe,
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.remove = bcm63xx_wdt_remove,
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.shutdown = bcm63xx_wdt_shutdown,
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.driver = {
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.name = "bcm63xx-wdt",
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}
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};
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module_platform_driver(bcm63xx_wdt_driver);
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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("platform:bcm63xx-wdt");
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