diff options
Diffstat (limited to 'drivers/watchdog/mtx-1_wdt.c')
| -rw-r--r-- | drivers/watchdog/mtx-1_wdt.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/drivers/watchdog/mtx-1_wdt.c b/drivers/watchdog/mtx-1_wdt.c new file mode 100644 index 00000000000..dcfd401a7ad --- /dev/null +++ b/drivers/watchdog/mtx-1_wdt.c @@ -0,0 +1,239 @@ +/* + * Driver for the MTX-1 Watchdog. + * + * (C) Copyright 2005 4G Systems <info@4g-systems.biz>, All Rights Reserved. + * http://www.4g-systems.biz + * + * (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Neither Michael Stickel nor 4G Systems admit liability nor provide + * warranty for any of this software. This material is provided + * "AS-IS" and at no charge. + * + * (c) Copyright 2005 4G Systems <info@4g-systems.biz> + * + * Release 0.01. + * Author: Michael Stickel michael.stickel@4g-systems.biz + * + * Release 0.02. + * Author: Florian Fainelli florian@openwrt.org + * use the Linux watchdog/timer APIs + * + * The Watchdog is configured to reset the MTX-1 + * if it is not triggered for 100 seconds. + * It should not be triggered more often than 1.6 seconds. + * + * A timer triggers the watchdog every 5 seconds, until + * it is opened for the first time. After the first open + * it MUST be triggered every 2..95 seconds. + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/miscdevice.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/ioport.h> +#include <linux/timer.h> +#include <linux/completion.h> +#include <linux/jiffies.h> +#include <linux/watchdog.h> +#include <asm/io.h> +#include <asm/uaccess.h> + +#include <asm/mach-au1x00/au1000.h> + +#define MTX1_WDT_INTERVAL (5 * HZ) + +static int ticks = 100 * HZ; + +static struct { + struct completion stop; + volatile int running; + struct timer_list timer; + volatile int queue; + int default_ticks; + unsigned long inuse; +} mtx1_wdt_device; + +static void mtx1_wdt_trigger(unsigned long unused) +{ + u32 tmp; + + if (mtx1_wdt_device.running) + ticks--; + /* + * toggle GPIO2_15 + */ + tmp = au_readl(GPIO2_DIR); + tmp = (tmp & ~(1<<15)) | ((~tmp) & (1<<15)); + au_writel (tmp, GPIO2_DIR); + + if (mtx1_wdt_device.queue && ticks) + mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL); + else { + complete(&mtx1_wdt_device.stop); + } +} + +static void mtx1_wdt_reset(void) +{ + ticks = mtx1_wdt_device.default_ticks; +} + + +static void mtx1_wdt_start(void) +{ + if (!mtx1_wdt_device.queue) { + mtx1_wdt_device.queue = 1; + au_writel (au_readl(GPIO2_DIR) | (u32)(1<<15), GPIO2_DIR); + mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL); + } + mtx1_wdt_device.running++; +} + +static int mtx1_wdt_stop(void) +{ + if (mtx1_wdt_device.queue) { + mtx1_wdt_device.queue = 0; + au_writel (au_readl(GPIO2_DIR) & ~((u32)(1<<15)), GPIO2_DIR); + } + + ticks = mtx1_wdt_device.default_ticks; + + return 0; +} + +/* Filesystem functions */ + +static int mtx1_wdt_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(0, &mtx1_wdt_device.inuse)) + return -EBUSY; + + return nonseekable_open(inode, file); +} + + +static int mtx1_wdt_release(struct inode *inode, struct file *file) +{ + clear_bit(0, &mtx1_wdt_device.inuse); + return 0; +} + +static int mtx1_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) +{ + void __user *argp = (void __user *)arg; + unsigned int value; + static struct watchdog_info ident = + { + .options = WDIOF_CARDRESET, + .identity = "MTX-1 WDT", + }; + + switch(cmd) { + case WDIOC_KEEPALIVE: + mtx1_wdt_reset(); + break; + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + if ( copy_to_user(argp, &value, sizeof(int)) ) + return -EFAULT; + break; + case WDIOC_GETSUPPORT: + if ( copy_to_user(argp, &ident, sizeof(ident)) ) + return -EFAULT; + break; + case WDIOC_SETOPTIONS: + if ( copy_from_user(&value, argp, sizeof(int)) ) + return -EFAULT; + switch(value) { + case WDIOS_ENABLECARD: + mtx1_wdt_start(); + break; + case WDIOS_DISABLECARD: + return mtx1_wdt_stop(); + default: + return -EINVAL; + } + break; + default: + return -ENOTTY; + } + return 0; +} + + +static ssize_t mtx1_wdt_write(struct file *file, const char *buf, size_t count, loff_t *ppos) +{ + if (!count) + return -EIO; + + mtx1_wdt_reset(); + return count; +} + +static struct file_operations mtx1_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .ioctl = mtx1_wdt_ioctl, + .open = mtx1_wdt_open, + .write = mtx1_wdt_write, + .release = mtx1_wdt_release +}; + + +static struct miscdevice mtx1_wdt_misc = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &mtx1_wdt_fops +}; + + +static int __init mtx1_wdt_init(void) +{ + int ret; + + if ((ret = misc_register(&mtx1_wdt_misc)) < 0) { + printk(KERN_ERR " mtx-1_wdt : failed to register\n"); + return ret; + } + + init_completion(&mtx1_wdt_device.stop); + mtx1_wdt_device.queue = 0; + + clear_bit(0, &mtx1_wdt_device.inuse); + + setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L); + + mtx1_wdt_device.default_ticks = ticks; + + mtx1_wdt_start(); + + printk(KERN_INFO "MTX-1 Watchdog driver\n"); + + return 0; +} + +static void __exit mtx1_wdt_exit(void) +{ + if (mtx1_wdt_device.queue) { + mtx1_wdt_device.queue = 0; + wait_for_completion(&mtx1_wdt_device.stop); + } + misc_deregister(&mtx1_wdt_misc); +} + +module_init(mtx1_wdt_init); +module_exit(mtx1_wdt_exit); + +MODULE_AUTHOR("Michael Stickel, Florian Fainelli"); +MODULE_DESCRIPTION("Driver for the MTX-1 watchdog"); +MODULE_LICENSE("GPL"); |