diff options
Diffstat (limited to 'drivers/watchdog/ixp4xx_wdt.c')
| -rw-r--r-- | drivers/watchdog/ixp4xx_wdt.c | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/drivers/watchdog/ixp4xx_wdt.c b/drivers/watchdog/ixp4xx_wdt.c new file mode 100644 index 000000000..f20cc53ff --- /dev/null +++ b/drivers/watchdog/ixp4xx_wdt.c @@ -0,0 +1,210 @@ +/* + * drivers/char/watchdog/ixp4xx_wdt.c + * + * Watchdog driver for Intel IXP4xx network processors + * + * 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. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#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 <linux/uaccess.h> +#include <mach/hardware.h> + +static bool nowayout = WATCHDOG_NOWAYOUT; +static int heartbeat = 60; /* (secs) Default is 1 minute */ +static unsigned long wdt_status; +static unsigned long boot_status; +static DEFINE_SPINLOCK(wdt_lock); + +#define WDT_TICK_RATE (IXP4XX_PERIPHERAL_BUS_CLOCK * 1000000UL) + +#define WDT_IN_USE 0 +#define WDT_OK_TO_CLOSE 1 + +static void wdt_enable(void) +{ + spin_lock(&wdt_lock); + *IXP4XX_OSWK = IXP4XX_WDT_KEY; + *IXP4XX_OSWE = 0; + *IXP4XX_OSWT = WDT_TICK_RATE * heartbeat; + *IXP4XX_OSWE = IXP4XX_WDT_COUNT_ENABLE | IXP4XX_WDT_RESET_ENABLE; + *IXP4XX_OSWK = 0; + spin_unlock(&wdt_lock); +} + +static void wdt_disable(void) +{ + spin_lock(&wdt_lock); + *IXP4XX_OSWK = IXP4XX_WDT_KEY; + *IXP4XX_OSWE = 0; + *IXP4XX_OSWK = 0; + spin_unlock(&wdt_lock); +} + +static int ixp4xx_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 +ixp4xx_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_enable(); + } + return len; +} + +static const struct watchdog_info ident = { + .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | + WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, + .identity = "IXP4xx Watchdog", +}; + + +static long ixp4xx_wdt_ioctl(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(boot_status, (int *)arg); + break; + + case WDIOC_KEEPALIVE: + wdt_enable(); + ret = 0; + break; + + case WDIOC_SETTIMEOUT: + ret = get_user(time, (int *)arg); + if (ret) + break; + + if (time <= 0 || time > 60) { + ret = -EINVAL; + break; + } + + heartbeat = time; + wdt_enable(); + /* Fall through */ + + case WDIOC_GETTIMEOUT: + ret = put_user(heartbeat, (int *)arg); + break; + } + return ret; +} + +static int ixp4xx_wdt_release(struct inode *inode, struct file *file) +{ + if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) + wdt_disable(); + else + pr_crit("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 ixp4xx_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = ixp4xx_wdt_write, + .unlocked_ioctl = ixp4xx_wdt_ioctl, + .open = ixp4xx_wdt_open, + .release = ixp4xx_wdt_release, +}; + +static struct miscdevice ixp4xx_wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &ixp4xx_wdt_fops, +}; + +static int __init ixp4xx_wdt_init(void) +{ + int ret; + + if (!(read_cpuid_id() & 0xf) && !cpu_is_ixp46x()) { + pr_err("Rev. A0 IXP42x CPU detected - watchdog disabled\n"); + + return -ENODEV; + } + boot_status = (*IXP4XX_OSST & IXP4XX_OSST_TIMER_WARM_RESET) ? + WDIOF_CARDRESET : 0; + ret = misc_register(&ixp4xx_wdt_miscdev); + if (ret == 0) + pr_info("timer heartbeat %d sec\n", heartbeat); + return ret; +} + +static void __exit ixp4xx_wdt_exit(void) +{ + misc_deregister(&ixp4xx_wdt_miscdev); +} + + +module_init(ixp4xx_wdt_init); +module_exit(ixp4xx_wdt_exit); + +MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>"); +MODULE_DESCRIPTION("IXP4xx Network Processor Watchdog"); + +module_param(heartbeat, int, 0); +MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)"); + +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); + +MODULE_LICENSE("GPL"); |