diff options
Diffstat (limited to 'drivers/watchdog/advantechwdt.c')
| -rw-r--r-- | drivers/watchdog/advantechwdt.c | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/drivers/watchdog/advantechwdt.c b/drivers/watchdog/advantechwdt.c new file mode 100644 index 000000000000..8121cc247343 --- /dev/null +++ b/drivers/watchdog/advantechwdt.c @@ -0,0 +1,362 @@ +/* + * Advantech Single Board Computer WDT driver + * + * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl> + * + * Based on acquirewdt.c which is based on wdt.c. + * Original copyright messages: + * + * (c) Copyright 1996 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@redhat.com> + * + * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com> + * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT + * + * 16-Oct-2002 Rob Radez <rob@osinvestor.com> + * Clean up ioctls, clean up init + exit, add expect close support, + * add wdt_start and wdt_stop as parameters. + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/miscdevice.h> +#include <linux/watchdog.h> +#include <linux/fs.h> +#include <linux/ioport.h> +#include <linux/platform_device.h> +#include <linux/init.h> + +#include <asm/io.h> +#include <asm/uaccess.h> +#include <asm/system.h> + +#define DRV_NAME "advantechwdt" +#define PFX DRV_NAME ": " +#define WATCHDOG_NAME "Advantech WDT" +#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ + +static struct platform_device *advwdt_platform_device; /* the watchdog platform device */ +static unsigned long advwdt_is_open; +static char adv_expect_close; + +/* + * You must set these - there is no sane way to probe for this board. + * + * To enable or restart, write the timeout value in seconds (1 to 63) + * to I/O port wdt_start. To disable, read I/O port wdt_stop. + * Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but + * check your manual (at least the PCA-6159 seems to be different - + * the manual says wdt_stop is 0x43, not 0x443). + * (0x43 is also a write-only control register for the 8254 timer!) + */ + +static int wdt_stop = 0x443; +module_param(wdt_stop, int, 0); +MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)"); + +static int wdt_start = 0x443; +module_param(wdt_start, int, 0); +MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)"); + +static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ +module_param(timeout, int, 0); +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) "."); + +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) ")"); + +/* + * Watchdog Operations + */ + +static void +advwdt_ping(void) +{ + /* Write a watchdog value */ + outb_p(timeout, wdt_start); +} + +static void +advwdt_disable(void) +{ + inb_p(wdt_stop); +} + +static int +advwdt_set_heartbeat(int t) +{ + if ((t < 1) || (t > 63)) + return -EINVAL; + + timeout = t; + return 0; +} + +/* + * /dev/watchdog handling + */ + +static ssize_t +advwdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) +{ + if (count) { + if (!nowayout) { + size_t i; + + adv_expect_close = 0; + + for (i = 0; i != count; i++) { + char c; + if (get_user(c, buf+i)) + return -EFAULT; + if (c == 'V') + adv_expect_close = 42; + } + } + advwdt_ping(); + } + return count; +} + +static int +advwdt_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 = WATCHDOG_NAME, + }; + + 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: + advwdt_ping(); + break; + + case WDIOC_SETTIMEOUT: + if (get_user(new_timeout, p)) + return -EFAULT; + if (advwdt_set_heartbeat(new_timeout)) + return -EINVAL; + advwdt_ping(); + /* 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) { + advwdt_disable(); + retval = 0; + } + + if (options & WDIOS_ENABLECARD) { + advwdt_ping(); + retval = 0; + } + + return retval; + } + + default: + return -ENOTTY; + } + return 0; +} + +static int +advwdt_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(0, &advwdt_is_open)) + return -EBUSY; + /* + * Activate + */ + + advwdt_ping(); + return nonseekable_open(inode, file); +} + +static int +advwdt_close(struct inode *inode, struct file *file) +{ + if (adv_expect_close == 42) { + advwdt_disable(); + } else { + printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); + advwdt_ping(); + } + clear_bit(0, &advwdt_is_open); + adv_expect_close = 0; + return 0; +} + +/* + * Kernel Interfaces + */ + +static const struct file_operations advwdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = advwdt_write, + .ioctl = advwdt_ioctl, + .open = advwdt_open, + .release = advwdt_close, +}; + +static struct miscdevice advwdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &advwdt_fops, +}; + +/* + * Init & exit routines + */ + +static int __devinit +advwdt_probe(struct platform_device *dev) +{ + int ret; + + if (wdt_stop != wdt_start) { + if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) { + printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", + wdt_stop); + ret = -EIO; + goto out; + } + } + + if (!request_region(wdt_start, 1, WATCHDOG_NAME)) { + printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", + wdt_start); + ret = -EIO; + goto unreg_stop; + } + + /* Check that the heartbeat value is within it's range ; if not reset to the default */ + if (advwdt_set_heartbeat(timeout)) { + advwdt_set_heartbeat(WATCHDOG_TIMEOUT); + printk (KERN_INFO PFX "timeout value must be 1<=x<=63, using %d\n", + timeout); + } + + ret = misc_register(&advwdt_miscdev); + if (ret != 0) { + printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", + WATCHDOG_MINOR, ret); + goto unreg_regions; + } + + printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", + timeout, nowayout); + +out: + return ret; +unreg_regions: + release_region(wdt_start, 1); +unreg_stop: + if (wdt_stop != wdt_start) + release_region(wdt_stop, 1); + goto out; +} + +static int __devexit +advwdt_remove(struct platform_device *dev) +{ + misc_deregister(&advwdt_miscdev); + release_region(wdt_start,1); + if(wdt_stop != wdt_start) + release_region(wdt_stop,1); + + return 0; +} + +static void +advwdt_shutdown(struct platform_device *dev) +{ + /* Turn the WDT off if we have a soft shutdown */ + advwdt_disable(); +} + +static struct platform_driver advwdt_driver = { + .probe = advwdt_probe, + .remove = __devexit_p(advwdt_remove), + .shutdown = advwdt_shutdown, + .driver = { + .owner = THIS_MODULE, + .name = DRV_NAME, + }, +}; + +static int __init +advwdt_init(void) +{ + int err; + + printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n"); + + err = platform_driver_register(&advwdt_driver); + if (err) + return err; + + advwdt_platform_device = platform_device_register_simple(DRV_NAME, -1, NULL, 0); + if (IS_ERR(advwdt_platform_device)) { + err = PTR_ERR(advwdt_platform_device); + goto unreg_platform_driver; + } + + return 0; + +unreg_platform_driver: + platform_driver_unregister(&advwdt_driver); + return err; +} + +static void __exit +advwdt_exit(void) +{ + platform_device_unregister(advwdt_platform_device); + platform_driver_unregister(&advwdt_driver); + printk(KERN_INFO PFX "Watchdog Module Unloaded.\n"); +} + +module_init(advwdt_init); +module_exit(advwdt_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>"); +MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |