diff options
Diffstat (limited to 'drivers/watchdog/ixp2000_wdt.c')
| -rw-r--r-- | drivers/watchdog/ixp2000_wdt.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/drivers/watchdog/ixp2000_wdt.c b/drivers/watchdog/ixp2000_wdt.c new file mode 100644 index 000000000000..dc7548dcaf35 --- /dev/null +++ b/drivers/watchdog/ixp2000_wdt.c @@ -0,0 +1,219 @@ +/* + * drivers/char/watchdog/ixp2000_wdt.c + * + * Watchdog driver for Intel IXP2000 network processors + * + * Adapted from the IXP4xx watchdog driver by Lennert Buytenhek. + * The original version carries these notices: + * + * Author: Deepak Saxena <dsaxena@plexity.net> + * + * Copyright 2004 (c) MontaVista, Software, Inc. + * Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/miscdevice.h> +#include <linux/watchdog.h> +#include <linux/init.h> +#include <linux/bitops.h> + +#include <asm/hardware.h> +#include <asm/uaccess.h> + +static int nowayout = WATCHDOG_NOWAYOUT; +static unsigned int heartbeat = 60; /* (secs) Default is 1 minute */ +static unsigned long wdt_status; + +#define WDT_IN_USE 0 +#define WDT_OK_TO_CLOSE 1 + +static unsigned long wdt_tick_rate; + +static void +wdt_enable(void) +{ + ixp2000_reg_write(IXP2000_RESET0, *(IXP2000_RESET0) | WDT_RESET_ENABLE); + ixp2000_reg_write(IXP2000_TWDE, WDT_ENABLE); + ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate); + ixp2000_reg_write(IXP2000_T4_CTL, TIMER_DIVIDER_256 | TIMER_ENABLE); +} + +static void +wdt_disable(void) +{ + ixp2000_reg_write(IXP2000_T4_CTL, 0); +} + +static void +wdt_keepalive(void) +{ + ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate); +} + +static int +ixp2000_wdt_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(WDT_IN_USE, &wdt_status)) + return -EBUSY; + + clear_bit(WDT_OK_TO_CLOSE, &wdt_status); + + wdt_enable(); + + return nonseekable_open(inode, file); +} + +static ssize_t +ixp2000_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) +{ + if (len) { + if (!nowayout) { + size_t i; + + clear_bit(WDT_OK_TO_CLOSE, &wdt_status); + + for (i = 0; i != len; i++) { + char c; + + if (get_user(c, data + i)) + return -EFAULT; + if (c == 'V') + set_bit(WDT_OK_TO_CLOSE, &wdt_status); + } + } + wdt_keepalive(); + } + + return len; +} + + +static struct watchdog_info ident = { + .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | + WDIOF_KEEPALIVEPING, + .identity = "IXP2000 Watchdog", +}; + +static int +ixp2000_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, + unsigned long arg) +{ + int ret = -ENOTTY; + int time; + + switch (cmd) { + case WDIOC_GETSUPPORT: + ret = copy_to_user((struct watchdog_info *)arg, &ident, + sizeof(ident)) ? -EFAULT : 0; + break; + + case WDIOC_GETSTATUS: + ret = put_user(0, (int *)arg); + break; + + case WDIOC_GETBOOTSTATUS: + ret = put_user(0, (int *)arg); + break; + + case WDIOC_SETTIMEOUT: + ret = get_user(time, (int *)arg); + if (ret) + break; + + if (time <= 0 || time > 60) { + ret = -EINVAL; + break; + } + + heartbeat = time; + wdt_keepalive(); + /* Fall through */ + + case WDIOC_GETTIMEOUT: + ret = put_user(heartbeat, (int *)arg); + break; + + case WDIOC_KEEPALIVE: + wdt_enable(); + ret = 0; + break; + } + + return ret; +} + +static int +ixp2000_wdt_release(struct inode *inode, struct file *file) +{ + if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) { + wdt_disable(); + } else { + printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - " + "timer will not stop\n"); + } + + clear_bit(WDT_IN_USE, &wdt_status); + clear_bit(WDT_OK_TO_CLOSE, &wdt_status); + + return 0; +} + + +static const struct file_operations ixp2000_wdt_fops = +{ + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = ixp2000_wdt_write, + .ioctl = ixp2000_wdt_ioctl, + .open = ixp2000_wdt_open, + .release = ixp2000_wdt_release, +}; + +static struct miscdevice ixp2000_wdt_miscdev = +{ + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &ixp2000_wdt_fops, +}; + +static int __init ixp2000_wdt_init(void) +{ + if ((*IXP2000_PRODUCT_ID & 0x001ffef0) == 0x00000000) { + printk(KERN_INFO "Unable to use IXP2000 watchdog due to IXP2800 erratum #25.\n"); + return -EIO; + } + + wdt_tick_rate = (*IXP2000_T1_CLD * HZ) / 256; + + return misc_register(&ixp2000_wdt_miscdev); +} + +static void __exit ixp2000_wdt_exit(void) +{ + misc_deregister(&ixp2000_wdt_miscdev); +} + +module_init(ixp2000_wdt_init); +module_exit(ixp2000_wdt_exit); + +MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>"); +MODULE_DESCRIPTION("IXP2000 Network Processor Watchdog"); + +module_param(heartbeat, int, 0); +MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)"); + +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); + +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); + |