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Diffstat (limited to 'package/kernel/avila-wdt/src/avila-wdt.c')
| -rw-r--r-- | package/kernel/avila-wdt/src/avila-wdt.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/package/kernel/avila-wdt/src/avila-wdt.c b/package/kernel/avila-wdt/src/avila-wdt.c new file mode 100644 index 0000000..981f385 --- /dev/null +++ b/package/kernel/avila-wdt/src/avila-wdt.c @@ -0,0 +1,231 @@ +/* + * avila-wdt.c + * Copyright (C) 2009 Felix Fietkau <nbd@openwrt.org> + * + * based on: + * 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. + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/jiffies.h> +#include <linux/timer.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 int nowayout = WATCHDOG_NOWAYOUT; +static int heartbeat = 20; /* (secs) Default is 20 seconds */ +static unsigned long wdt_status; +static atomic_t wdt_counter; +struct timer_list wdt_timer; + +#define WDT_IN_USE 0 +#define WDT_OK_TO_CLOSE 1 +#define WDT_RUNNING 2 + +static void wdt_refresh(unsigned long data) +{ + if (test_bit(WDT_RUNNING, &wdt_status)) { + if (atomic_dec_and_test(&wdt_counter)) { + printk(KERN_WARNING "Avila watchdog expired, expect a reboot soon!\n"); + clear_bit(WDT_RUNNING, &wdt_status); + return; + } + } + + /* strobe to the watchdog */ + gpio_line_set(14, IXP4XX_GPIO_HIGH); + gpio_line_set(14, IXP4XX_GPIO_LOW); + + mod_timer(&wdt_timer, jiffies + msecs_to_jiffies(500)); +} + +static void wdt_enable(void) +{ + atomic_set(&wdt_counter, heartbeat * 2); + + /* Disable clock generator output on GPIO 14/15 */ + *IXP4XX_GPIO_GPCLKR &= ~(1 << 8); + + /* activate GPIO 14 out */ + gpio_line_config(14, IXP4XX_GPIO_OUT); + gpio_line_set(14, IXP4XX_GPIO_LOW); + + if (!test_bit(WDT_RUNNING, &wdt_status)) + wdt_refresh(0); + set_bit(WDT_RUNNING, &wdt_status); +} + +static void wdt_disable(void) +{ + /* Re-enable clock generator output on GPIO 14/15 */ + *IXP4XX_GPIO_GPCLKR |= (1 << 8); +} + +static int avila_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 +avila_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 struct watchdog_info ident = { + .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | + WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, + .identity = "Avila Watchdog", +}; + + +static long avila_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_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 avila_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 avila_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = avila_wdt_write, + .unlocked_ioctl = avila_wdt_ioctl, + .open = avila_wdt_open, + .release = avila_wdt_release, +}; + +static struct miscdevice avila_wdt_miscdev = { + .minor = WATCHDOG_MINOR + 1, + .name = "avila_watchdog", + .fops = &avila_wdt_fops, +}; + +static int __init avila_wdt_init(void) +{ + int ret; + + init_timer(&wdt_timer); + wdt_timer.expires = 0; + wdt_timer.data = 0; + wdt_timer.function = wdt_refresh; + ret = misc_register(&avila_wdt_miscdev); + if (ret == 0) + printk(KERN_INFO "Avila Watchdog Timer: heartbeat %d sec\n", + heartbeat); + return ret; +} + +static void __exit avila_wdt_exit(void) +{ + misc_deregister(&avila_wdt_miscdev); + del_timer(&wdt_timer); + wdt_disable(); +} + + +module_init(avila_wdt_init); +module_exit(avila_wdt_exit); + +MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>"); +MODULE_DESCRIPTION("Gateworks Avila Hardware Watchdog"); + +module_param(heartbeat, int, 0); +MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 20s)"); + +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); + +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); + |