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220 lines
4.9 KiB
220 lines
4.9 KiB
/* |
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* drivers/char/watchdog/ixp4xx_wdt.c |
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* |
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* Watchdog driver for Intel IXP4xx network processors |
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* |
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* Author: Deepak Saxena <[email protected]> |
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* |
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* Copyright 2004 (c) MontaVista, Software, Inc. |
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* Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <[email protected]> |
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* |
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* This file is licensed under the terms of the GNU General Public |
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* License version 2. This program is licensed "as is" without any |
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* warranty of any kind, whether express or implied. |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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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/kernel.h> |
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#include <linux/fs.h> |
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#include <linux/miscdevice.h> |
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#include <linux/of.h> |
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#include <linux/watchdog.h> |
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#include <linux/init.h> |
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#include <linux/bitops.h> |
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#include <linux/uaccess.h> |
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#include <mach/hardware.h> |
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static bool nowayout = WATCHDOG_NOWAYOUT; |
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static int heartbeat = 60; /* (secs) Default is 1 minute */ |
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static unsigned long wdt_status; |
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static unsigned long boot_status; |
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static DEFINE_SPINLOCK(wdt_lock); |
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#define WDT_TICK_RATE (IXP4XX_PERIPHERAL_BUS_CLOCK * 1000000UL) |
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#define WDT_IN_USE 0 |
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#define WDT_OK_TO_CLOSE 1 |
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static void wdt_enable(void) |
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{ |
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spin_lock(&wdt_lock); |
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*IXP4XX_OSWK = IXP4XX_WDT_KEY; |
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*IXP4XX_OSWE = 0; |
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*IXP4XX_OSWT = WDT_TICK_RATE * heartbeat; |
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*IXP4XX_OSWE = IXP4XX_WDT_COUNT_ENABLE | IXP4XX_WDT_RESET_ENABLE; |
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*IXP4XX_OSWK = 0; |
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spin_unlock(&wdt_lock); |
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} |
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static void wdt_disable(void) |
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{ |
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spin_lock(&wdt_lock); |
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*IXP4XX_OSWK = IXP4XX_WDT_KEY; |
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*IXP4XX_OSWE = 0; |
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*IXP4XX_OSWK = 0; |
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spin_unlock(&wdt_lock); |
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} |
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static int ixp4xx_wdt_open(struct inode *inode, struct file *file) |
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{ |
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if (test_and_set_bit(WDT_IN_USE, &wdt_status)) |
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return -EBUSY; |
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clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
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wdt_enable(); |
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return stream_open(inode, file); |
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} |
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static ssize_t |
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ixp4xx_wdt_write(struct file *file, const char *data, 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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clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
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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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set_bit(WDT_OK_TO_CLOSE, &wdt_status); |
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} |
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} |
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wdt_enable(); |
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} |
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return len; |
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} |
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static const struct watchdog_info ident = { |
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.options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | |
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WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, |
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.identity = "IXP4xx Watchdog", |
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}; |
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static long ixp4xx_wdt_ioctl(struct file *file, unsigned int cmd, |
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unsigned long arg) |
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{ |
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int ret = -ENOTTY; |
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int time; |
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switch (cmd) { |
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case WDIOC_GETSUPPORT: |
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ret = copy_to_user((struct watchdog_info *)arg, &ident, |
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sizeof(ident)) ? -EFAULT : 0; |
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break; |
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case WDIOC_GETSTATUS: |
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ret = put_user(0, (int *)arg); |
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break; |
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case WDIOC_GETBOOTSTATUS: |
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ret = put_user(boot_status, (int *)arg); |
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break; |
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case WDIOC_KEEPALIVE: |
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wdt_enable(); |
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ret = 0; |
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break; |
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case WDIOC_SETTIMEOUT: |
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ret = get_user(time, (int *)arg); |
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if (ret) |
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break; |
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if (time <= 0 || time > 60) { |
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ret = -EINVAL; |
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break; |
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} |
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heartbeat = time; |
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wdt_enable(); |
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fallthrough; |
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case WDIOC_GETTIMEOUT: |
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ret = put_user(heartbeat, (int *)arg); |
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break; |
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} |
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return ret; |
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} |
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static int ixp4xx_wdt_release(struct inode *inode, struct file *file) |
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{ |
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if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) |
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wdt_disable(); |
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else |
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pr_crit("Device closed unexpectedly - timer will not stop\n"); |
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clear_bit(WDT_IN_USE, &wdt_status); |
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clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
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return 0; |
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} |
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static const struct file_operations ixp4xx_wdt_fops = { |
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.owner = THIS_MODULE, |
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.llseek = no_llseek, |
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.write = ixp4xx_wdt_write, |
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.unlocked_ioctl = ixp4xx_wdt_ioctl, |
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.compat_ioctl = compat_ptr_ioctl, |
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.open = ixp4xx_wdt_open, |
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.release = ixp4xx_wdt_release, |
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}; |
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static struct miscdevice ixp4xx_wdt_miscdev = { |
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.minor = WATCHDOG_MINOR, |
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.name = "watchdog", |
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.fops = &ixp4xx_wdt_fops, |
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}; |
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static int __init ixp4xx_wdt_init(void) |
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{ |
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int ret; |
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/* |
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* FIXME: we bail out on device tree boot but this really needs |
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* to be fixed in a nicer way: this registers the MDIO bus before |
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* even matching the driver infrastructure, we should only probe |
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* detected hardware. |
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*/ |
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if (of_have_populated_dt()) |
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return -ENODEV; |
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if (!(read_cpuid_id() & 0xf) && !cpu_is_ixp46x()) { |
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pr_err("Rev. A0 IXP42x CPU detected - watchdog disabled\n"); |
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return -ENODEV; |
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} |
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boot_status = (*IXP4XX_OSST & IXP4XX_OSST_TIMER_WARM_RESET) ? |
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WDIOF_CARDRESET : 0; |
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ret = misc_register(&ixp4xx_wdt_miscdev); |
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if (ret == 0) |
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pr_info("timer heartbeat %d sec\n", heartbeat); |
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return ret; |
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} |
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static void __exit ixp4xx_wdt_exit(void) |
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{ |
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misc_deregister(&ixp4xx_wdt_miscdev); |
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} |
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module_init(ixp4xx_wdt_init); |
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module_exit(ixp4xx_wdt_exit); |
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MODULE_AUTHOR("Deepak Saxena <[email protected]>"); |
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MODULE_DESCRIPTION("IXP4xx Network Processor Watchdog"); |
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module_param(heartbeat, int, 0); |
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MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)"); |
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module_param(nowayout, bool, 0); |
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); |
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MODULE_LICENSE("GPL");
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