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315 lines
6.8 KiB
315 lines
6.8 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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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 <[email protected]> |
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* Copyright (C) 2008, Florian Fainelli <[email protected]> |
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* |
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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(struct timer_list *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 stream_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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.compat_ioctl = compat_ptr_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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timer_setup(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0); |
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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(&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 <[email protected]>"); |
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MODULE_AUTHOR("Florian Fainelli <[email protected]>"); |
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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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