diff options
Diffstat (limited to 'target/linux/rb532/files-2.6.24/drivers/char/watchdog/rc32434_wdt.c')
| -rw-r--r-- | target/linux/rb532/files-2.6.24/drivers/char/watchdog/rc32434_wdt.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/target/linux/rb532/files-2.6.24/drivers/char/watchdog/rc32434_wdt.c b/target/linux/rb532/files-2.6.24/drivers/char/watchdog/rc32434_wdt.c new file mode 100644 index 000000000..2266329de --- /dev/null +++ b/target/linux/rb532/files-2.6.24/drivers/char/watchdog/rc32434_wdt.c @@ -0,0 +1,240 @@ +/* + * RC32434_WDT 0.01: IDT Interprise 79RC32434 watchdog driver + * Copyright (c) Ondrej Zajicek <santiago@crfreenet.org>, 2006 + * + * based on + * + * SoftDog 0.05: A Software Watchdog Device + * + * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved. + * + * 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. + * + */ + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/miscdevice.h> +#include <linux/watchdog.h> +#include <linux/reboot.h> +#include <linux/smp_lock.h> +#include <linux/init.h> +#include <asm/bootinfo.h> +#include <asm/time.h> +#include <asm/uaccess.h> +#include <asm/rc32434/integ.h> + +#define DEFAULT_TIMEOUT 15 /* (secs) Default is 15 seconds */ +#define MAX_TIMEOUT 20 +/* + * (secs) Max is 20 seconds + * (max frequency of counter is ~200 MHz, counter is 32-bit unsigned int) + */ + +#define NAME "rc32434_wdt" +#define VERSION "0.1" + +static INTEG_t rc_wdt = (INTEG_t) INTEG_VirtualAddress; + +static int expect_close = 0; +static int access = 0; +static int timeout = 0; + +static int nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); +MODULE_LICENSE("GPL"); + + +static inline void start_wdt(void) +{ + rc_wdt -> wtcount = 0; + rc_wdt -> errcs |= ERRCS_wre_m; + rc_wdt -> wtc |= WTC_en_m; +} + +static inline void stop_wdt(void) +{ + rc_wdt -> wtc &= ~WTC_en_m; + rc_wdt -> errcs &= ~ERRCS_wre_m; +} + +static inline void set_wdt(int new_timeout) +{ + u32 cmp = new_timeout * mips_hpt_frequency; + u32 state; + + timeout = new_timeout; + /* + * store and disable WTC + */ + state = rc_wdt -> wtc & WTC_en_m; + rc_wdt -> wtc &= ~WTC_en_m; + + rc_wdt -> wtcount = 0; + rc_wdt -> wtcompare = cmp; + + /* + * restore WTC + */ + rc_wdt -> wtc |= state; +} + +static inline void update_wdt(void) +{ + rc_wdt -> wtcount = 0; +} + +/* + * Allow only one person to hold it open + */ + +static int wdt_open(struct inode *inode, struct file *file) +{ + if (access) + return -EBUSY; + if (nowayout) { + __module_get(THIS_MODULE); + } + /* + * Activate timer + */ + start_wdt(); + printk(KERN_INFO NAME ": enabling watchdog timer\n"); + access = 1; + return 0; +} + +static int wdt_release(struct inode *inode, struct file *file) +{ + /* + * Shut off the timer. + * Lock it in if it's a module and we set nowayout + */ + if (expect_close && nowayout == 0) { + stop_wdt (); + printk(KERN_INFO NAME ": disabling watchdog timer\n"); + module_put(THIS_MODULE); + } else { + printk (KERN_CRIT NAME ": device closed unexpectedly. WDT will not stop!\n"); + } + access = 0; + return 0; +} + +static ssize_t wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) +{ + /* + * Refresh the timer. + */ + if (len) { + if (!nowayout) { + size_t i; + + /* In case it was set long ago */ + expect_close = 0; + + for (i = 0; i != len; i++) { + char c; + if (get_user(c, data + i)) + return -EFAULT; + if (c == 'V') + expect_close = 1; + } + } + update_wdt (); + return len; + } + return 0; +} + +static int wdt_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg) +{ + int new_timeout; + static struct watchdog_info ident = { + .options = WDIOF_SETTIMEOUT | + WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE, + .firmware_version = 0, + .identity = "RC32434_WDT Watchdog", + }; + switch (cmd) { + default: + return -ENOTTY; + case WDIOC_GETSUPPORT: + if(copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident))) + return -EFAULT; + return 0; + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + return put_user(0,(int *)arg); + case WDIOC_KEEPALIVE: + update_wdt(); + return 0; + case WDIOC_SETTIMEOUT: + if (get_user(new_timeout, (int *)arg)) + return -EFAULT; + if (new_timeout < 1) + return -EINVAL; + if (new_timeout > MAX_TIMEOUT) + return -EINVAL; + set_wdt(new_timeout); + /* Fall */ + case WDIOC_GETTIMEOUT: + return put_user(timeout, (int *)arg); + } +} + +static struct file_operations wdt_fops = { + owner: THIS_MODULE, + llseek: no_llseek, + write: wdt_write, + ioctl: wdt_ioctl, + open: wdt_open, + release: wdt_release, +}; + +static struct miscdevice wdt_miscdev = { + minor: WATCHDOG_MINOR, + name: "watchdog", + fops: &wdt_fops, +}; + +static char banner[] __initdata = KERN_INFO NAME ": Watchdog Timer version " VERSION ", timer margin: %d sec\n"; + +static int __init watchdog_init(void) +{ + int ret; + + /* + * There should be check for RC32434 SoC + */ + if (mips_machgroup != MACH_GROUP_MIKROTIK) return -1; + + ret = misc_register(&wdt_miscdev); + + if (ret) + return ret; + + stop_wdt(); + set_wdt(DEFAULT_TIMEOUT); + + printk(banner, timeout); + + return 0; +} + +static void __exit watchdog_exit(void) +{ + misc_deregister(&wdt_miscdev); +} + +module_init(watchdog_init); +module_exit(watchdog_exit); |