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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/watchdog/wafer5823wdt.c | |
download | kernel_samsung_smdk4412-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip kernel_samsung_smdk4412-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz kernel_samsung_smdk4412-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/char/watchdog/wafer5823wdt.c')
-rw-r--r-- | drivers/char/watchdog/wafer5823wdt.c | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/drivers/char/watchdog/wafer5823wdt.c b/drivers/char/watchdog/wafer5823wdt.c new file mode 100644 index 0000000..abb0bea --- /dev/null +++ b/drivers/char/watchdog/wafer5823wdt.c @@ -0,0 +1,330 @@ +/* + * ICP Wafer 5823 Single Board Computer WDT driver + * http://www.icpamerica.com/wafer_5823.php + * May also work on other similar models + * + * (c) Copyright 2002 Justin Cormack <justin@street-vision.com> + * + * Release 0.02 + * + * Based on advantechwdt.c which is based on wdt.c. + * Original copyright messages: + * + * (c) Copyright 1996-1997 Alan Cox <alan@redhat.com>, All Rights Reserved. + * http://www.redhat.com + * + * 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 Alan Cox nor CymruNet Ltd. admit liability nor provide + * warranty for any of this software. This material is provided + * "AS-IS" and at no charge. + * + * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk> + * + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/miscdevice.h> +#include <linux/watchdog.h> +#include <linux/fs.h> +#include <linux/ioport.h> +#include <linux/notifier.h> +#include <linux/reboot.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <asm/io.h> +#include <asm/uaccess.h> + +#define WATCHDOG_NAME "Wafer 5823 WDT" +#define PFX WATCHDOG_NAME ": " +#define WD_TIMO 60 /* 60 sec default timeout */ + +static unsigned long wafwdt_is_open; +static char expect_close; +static spinlock_t wafwdt_lock; + +/* + * You must set these - there is no sane way to probe for this board. + * + * To enable, write the timeout value in seconds (1 to 255) to I/O + * port WDT_START, then read the port to start the watchdog. To pat + * the dog, read port WDT_STOP to stop the timer, then read WDT_START + * to restart it again. + */ + +static int wdt_stop = 0x843; +static int wdt_start = 0x443; + +static int timeout = WD_TIMO; /* in seconds */ +module_param(timeout, int, 0); +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=255, default=" __MODULE_STRING(WD_TIMO) "."); + +#ifdef CONFIG_WATCHDOG_NOWAYOUT +static int nowayout = 1; +#else +static int nowayout = 0; +#endif + +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); + +static void wafwdt_ping(void) +{ + /* pat watchdog */ + spin_lock(&wafwdt_lock); + inb_p(wdt_stop); + inb_p(wdt_start); + spin_unlock(&wafwdt_lock); +} + +static void wafwdt_start(void) +{ + /* start up watchdog */ + outb_p(timeout, wdt_start); + inb_p(wdt_start); +} + +static void +wafwdt_stop(void) +{ + /* stop watchdog */ + inb_p(wdt_stop); +} + +static ssize_t wafwdt_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos) +{ + /* See if we got the magic character 'V' and reload the timer */ + if (count) { + if (!nowayout) { + size_t i; + + /* In case it was set long ago */ + expect_close = 0; + + /* scan to see whether or not we got the magic character */ + for (i = 0; i != count; i++) { + char c; + if (get_user(c, buf + i)) + return -EFAULT; + if (c == 'V') + expect_close = 42; + } + } + /* Well, anyhow someone wrote to us, we should return that favour */ + wafwdt_ping(); + } + return count; +} + +static int wafwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, + unsigned long arg) +{ + int new_timeout; + void __user *argp = (void __user *)arg; + int __user *p = argp; + static struct watchdog_info ident = { + .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, + .firmware_version = 1, + .identity = "Wafer 5823 WDT", + }; + + switch (cmd) { + case WDIOC_GETSUPPORT: + if (copy_to_user(argp, &ident, sizeof (ident))) + return -EFAULT; + break; + + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + return put_user(0, p); + + case WDIOC_KEEPALIVE: + wafwdt_ping(); + break; + + case WDIOC_SETTIMEOUT: + if (get_user(new_timeout, p)) + return -EFAULT; + if ((new_timeout < 1) || (new_timeout > 255)) + return -EINVAL; + timeout = new_timeout; + wafwdt_stop(); + wafwdt_start(); + /* Fall */ + case WDIOC_GETTIMEOUT: + return put_user(timeout, p); + + case WDIOC_SETOPTIONS: + { + int options, retval = -EINVAL; + + if (get_user(options, p)) + return -EFAULT; + + if (options & WDIOS_DISABLECARD) { + wafwdt_start(); + retval = 0; + } + + if (options & WDIOS_ENABLECARD) { + wafwdt_stop(); + retval = 0; + } + + return retval; + } + + default: + return -ENOIOCTLCMD; + } + return 0; +} + +static int wafwdt_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(0, &wafwdt_is_open)) + return -EBUSY; + + /* + * Activate + */ + wafwdt_start(); + return nonseekable_open(inode, file); +} + +static int +wafwdt_close(struct inode *inode, struct file *file) +{ + if (expect_close == 42) { + wafwdt_stop(); + } else { + printk(KERN_CRIT PFX "WDT device closed unexpectedly. WDT will not stop!\n"); + wafwdt_ping(); + } + clear_bit(0, &wafwdt_is_open); + expect_close = 0; + return 0; +} + +/* + * Notifier for system down + */ + +static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) +{ + if (code == SYS_DOWN || code == SYS_HALT) { + /* Turn the WDT off */ + wafwdt_stop(); + } + return NOTIFY_DONE; +} + +/* + * Kernel Interfaces + */ + +static struct file_operations wafwdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = wafwdt_write, + .ioctl = wafwdt_ioctl, + .open = wafwdt_open, + .release = wafwdt_close, +}; + +static struct miscdevice wafwdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &wafwdt_fops, +}; + +/* + * The WDT needs to learn about soft shutdowns in order to + * turn the timebomb registers off. + */ + +static struct notifier_block wafwdt_notifier = { + .notifier_call = wafwdt_notify_sys, +}; + +static int __init wafwdt_init(void) +{ + int ret; + + printk(KERN_INFO "WDT driver for Wafer 5823 single board computer initialising.\n"); + + spin_lock_init(&wafwdt_lock); + + if (timeout < 1 || timeout > 255) { + timeout = WD_TIMO; + printk (KERN_INFO PFX "timeout value must be 1<=x<=255, using %d\n", + timeout); + } + + if (wdt_stop != wdt_start) { + if(!request_region(wdt_stop, 1, "Wafer 5823 WDT")) { + printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", + wdt_stop); + ret = -EIO; + goto error; + } + } + + if(!request_region(wdt_start, 1, "Wafer 5823 WDT")) { + printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", + wdt_start); + ret = -EIO; + goto error2; + } + + ret = register_reboot_notifier(&wafwdt_notifier); + if (ret != 0) { + printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", + ret); + goto error3; + } + + ret = misc_register(&wafwdt_miscdev); + if (ret != 0) { + printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", + WATCHDOG_MINOR, ret); + goto error4; + } + + printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", + timeout, nowayout); + + return ret; +error4: + unregister_reboot_notifier(&wafwdt_notifier); +error3: + release_region(wdt_start, 1); +error2: + if (wdt_stop != wdt_start) + release_region(wdt_stop, 1); +error: + return ret; +} + +static void __exit wafwdt_exit(void) +{ + misc_deregister(&wafwdt_miscdev); + unregister_reboot_notifier(&wafwdt_notifier); + if(wdt_stop != wdt_start) + release_region(wdt_stop, 1); + release_region(wdt_start, 1); +} + +module_init(wafwdt_init); +module_exit(wafwdt_exit); + +MODULE_AUTHOR("Justin Cormack"); +MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); + +/* end of wafer5823wdt.c */ |