diff options
Diffstat (limited to 'drivers/char/watchdog/ep93xx_wdt.c')
| -rw-r--r-- | drivers/char/watchdog/ep93xx_wdt.c | 253 |
1 files changed, 0 insertions, 253 deletions
diff --git a/drivers/char/watchdog/ep93xx_wdt.c b/drivers/char/watchdog/ep93xx_wdt.c deleted file mode 100644 index 0e4787a..0000000 --- a/drivers/char/watchdog/ep93xx_wdt.c +++ /dev/null @@ -1,253 +0,0 @@ -/* - * Watchdog driver for Cirrus Logic EP93xx family of devices. - * - * Copyright (c) 2004 Ray Lehtiniemi - * Copyright (c) 2006 Tower Technologies - * Based on ep93xx driver, bits from alim7101_wdt.c - * - * Authors: Ray Lehtiniemi <rayl@mail.com>, - * Alessandro Zummo <a.zummo@towertech.it> - * - * 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. - * - * This watchdog fires after 250msec, which is a too short interval - * for us to rely on the user space daemon alone. So we ping the - * wdt each ~200msec and eventually stop doing it if the user space - * daemon dies. - * - * TODO: - * - * - Test last reset from watchdog status - * - Add a few missing ioctls - */ - -#include <linux/module.h> -#include <linux/fs.h> -#include <linux/miscdevice.h> -#include <linux/watchdog.h> -#include <linux/timer.h> - -#include <asm/hardware.h> -#include <asm/uaccess.h> - -#define WDT_VERSION "0.3" -#define PFX "ep93xx_wdt: " - -/* default timeout (secs) */ -#define WDT_TIMEOUT 30 - -static int nowayout = WATCHDOG_NOWAYOUT; -static int timeout = WDT_TIMEOUT; - -static struct timer_list timer; -static unsigned long next_heartbeat; -static unsigned long wdt_status; -static unsigned long boot_status; - -#define WDT_IN_USE 0 -#define WDT_OK_TO_CLOSE 1 - -#define EP93XX_WDT_REG(x) (EP93XX_WATCHDOG_BASE + (x)) -#define EP93XX_WDT_WATCHDOG EP93XX_WDT_REG(0x00) -#define EP93XX_WDT_WDSTATUS EP93XX_WDT_REG(0x04) - -/* reset the wdt every ~200ms */ -#define WDT_INTERVAL (HZ/5) - -static void wdt_enable(void) -{ - __raw_writew(0xaaaa, EP93XX_WDT_WATCHDOG); -} - -static void wdt_disable(void) -{ - __raw_writew(0xaa55, EP93XX_WDT_WATCHDOG); -} - -static inline void wdt_ping(void) -{ - __raw_writew(0x5555, EP93XX_WDT_WATCHDOG); -} - -static void wdt_startup(void) -{ - next_heartbeat = jiffies + (timeout * HZ); - - wdt_enable(); - mod_timer(&timer, jiffies + WDT_INTERVAL); -} - -static void wdt_shutdown(void) -{ - del_timer_sync(&timer); - wdt_disable(); -} - -static void wdt_keepalive(void) -{ - /* user land ping */ - next_heartbeat = jiffies + (timeout * HZ); -} - -static int ep93xx_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_startup(); - - return nonseekable_open(inode, file); -} - -static ssize_t -ep93xx_wdt_write(struct file *file, const char __user *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); - else - clear_bit(WDT_OK_TO_CLOSE, &wdt_status); - } - } - wdt_keepalive(); - } - - return len; -} - -static struct watchdog_info ident = { - .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE, - .identity = "EP93xx Watchdog", -}; - -static int -ep93xx_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, - unsigned long arg) -{ - int ret = -ENOTTY; - - switch (cmd) { - case WDIOC_GETSUPPORT: - ret = copy_to_user((struct watchdog_info __user *)arg, &ident, - sizeof(ident)) ? -EFAULT : 0; - break; - - case WDIOC_GETSTATUS: - ret = put_user(0, (int __user *)arg); - break; - - case WDIOC_GETBOOTSTATUS: - ret = put_user(boot_status, (int __user *)arg); - break; - - case WDIOC_GETTIMEOUT: - /* actually, it is 0.250 seconds.... */ - ret = put_user(1, (int __user *)arg); - break; - - case WDIOC_KEEPALIVE: - wdt_keepalive(); - ret = 0; - break; - } - return ret; -} - -static int ep93xx_wdt_release(struct inode *inode, struct file *file) -{ - if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) - wdt_shutdown(); - else - printk(KERN_CRIT PFX "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 ep93xx_wdt_fops = { - .owner = THIS_MODULE, - .write = ep93xx_wdt_write, - .ioctl = ep93xx_wdt_ioctl, - .open = ep93xx_wdt_open, - .release = ep93xx_wdt_release, -}; - -static struct miscdevice ep93xx_wdt_miscdev = { - .minor = WATCHDOG_MINOR, - .name = "watchdog", - .fops = &ep93xx_wdt_fops, -}; - -static void ep93xx_timer_ping(unsigned long data) -{ - if (time_before(jiffies, next_heartbeat)) - wdt_ping(); - - /* Re-set the timer interval */ - mod_timer(&timer, jiffies + WDT_INTERVAL); -} - -static int __init ep93xx_wdt_init(void) -{ - int err; - - err = misc_register(&ep93xx_wdt_miscdev); - - boot_status = __raw_readl(EP93XX_WDT_WATCHDOG) & 0x01 ? 1 : 0; - - printk(KERN_INFO PFX "EP93XX watchdog, driver version " - WDT_VERSION "%s\n", - (__raw_readl(EP93XX_WDT_WATCHDOG) & 0x08) - ? " (nCS1 disable detected)" : ""); - - if (timeout < 1 || timeout > 3600) { - timeout = WDT_TIMEOUT; - printk(KERN_INFO PFX - "timeout value must be 1<=x<=3600, using %d\n", - timeout); - } - - setup_timer(&timer, ep93xx_timer_ping, 1); - return err; -} - -static void __exit ep93xx_wdt_exit(void) -{ - wdt_shutdown(); - misc_deregister(&ep93xx_wdt_miscdev); -} - -module_init(ep93xx_wdt_init); -module_exit(ep93xx_wdt_exit); - -module_param(nowayout, int, 0); -MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); - -module_param(timeout, int, 0); -MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=3600, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); - -MODULE_AUTHOR("Ray Lehtiniemi <rayl@mail.com>," - "Alessandro Zummo <a.zummo@towertech.it>"); -MODULE_DESCRIPTION("EP93xx Watchdog"); -MODULE_LICENSE("GPL"); -MODULE_VERSION(WDT_VERSION); -MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |