diff options
Diffstat (limited to 'drivers/watchdog/ib700wdt.c')
| -rw-r--r-- | drivers/watchdog/ib700wdt.c | 408 |
1 files changed, 408 insertions, 0 deletions
diff --git a/drivers/watchdog/ib700wdt.c b/drivers/watchdog/ib700wdt.c new file mode 100644 index 000000000000..c3a60f52ccb9 --- /dev/null +++ b/drivers/watchdog/ib700wdt.c @@ -0,0 +1,408 @@ +/* + * IB700 Single Board Computer WDT driver + * + * (c) Copyright 2001 Charles Howes <chowes@vsol.net> + * + * Based on advantechwdt.c which is based on acquirewdt.c which + * is based on wdt.c. + * + * (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 + * Added timeout module option to override default + * + */ + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/miscdevice.h> +#include <linux/watchdog.h> +#include <linux/ioport.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/moduleparam.h> +#include <linux/platform_device.h> + +#include <asm/io.h> +#include <asm/uaccess.h> +#include <asm/system.h> + +static struct platform_device *ibwdt_platform_device; +static unsigned long ibwdt_is_open; +static spinlock_t ibwdt_lock; +static char expect_close; + +/* Module information */ +#define DRV_NAME "ib700wdt" +#define PFX DRV_NAME ": " + +/* + * + * Watchdog Timer Configuration + * + * The function of the watchdog timer is to reset the system + * automatically and is defined at I/O port 0443H. To enable the + * watchdog timer and allow the system to reset, write I/O port 0443H. + * To disable the timer, write I/O port 0441H for the system to stop the + * watchdog function. The timer has a tolerance of 20% for its + * intervals. + * + * The following describes how the timer should be programmed. + * + * Enabling Watchdog: + * MOV AX,000FH (Choose the values from 0 to F) + * MOV DX,0443H + * OUT DX,AX + * + * Disabling Watchdog: + * MOV AX,000FH (Any value is fine.) + * MOV DX,0441H + * OUT DX,AX + * + * Watchdog timer control table: + * Level Value Time/sec | Level Value Time/sec + * 1 F 0 | 9 7 16 + * 2 E 2 | 10 6 18 + * 3 D 4 | 11 5 20 + * 4 C 6 | 12 4 22 + * 5 B 8 | 13 3 24 + * 6 A 10 | 14 2 26 + * 7 9 12 | 15 1 28 + * 8 8 14 | 16 0 30 + * + */ + +static int wd_times[] = { + 30, /* 0x0 */ + 28, /* 0x1 */ + 26, /* 0x2 */ + 24, /* 0x3 */ + 22, /* 0x4 */ + 20, /* 0x5 */ + 18, /* 0x6 */ + 16, /* 0x7 */ + 14, /* 0x8 */ + 12, /* 0x9 */ + 10, /* 0xA */ + 8, /* 0xB */ + 6, /* 0xC */ + 4, /* 0xD */ + 2, /* 0xE */ + 0, /* 0xF */ +}; + +#define WDT_STOP 0x441 +#define WDT_START 0x443 + +/* Default timeout */ +#define WD_TIMO 0 /* 30 seconds +/- 20%, from table */ + +static int wd_margin = WD_TIMO; + +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 +ibwdt_ping(void) +{ + spin_lock(&ibwdt_lock); + + /* Write a watchdog value */ + outb_p(wd_margin, WDT_START); + + spin_unlock(&ibwdt_lock); +} + +static void +ibwdt_disable(void) +{ + spin_lock(&ibwdt_lock); + outb_p(0, WDT_STOP); + spin_unlock(&ibwdt_lock); +} + +static int +ibwdt_set_heartbeat(int t) +{ + int i; + + if ((t < 0) || (t > 30)) + return -EINVAL; + + for (i = 0x0F; i > -1; i--) + if (wd_times[i] > t) + break; + wd_margin = i; + return 0; +} + +/* + * /dev/watchdog handling + */ + +static ssize_t +ibwdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) +{ + if (count) { + if (!nowayout) { + size_t i; + + /* In case it was set long ago */ + expect_close = 0; + + for (i = 0; i != count; i++) { + char c; + if (get_user(c, buf + i)) + return -EFAULT; + if (c == 'V') + expect_close = 42; + } + } + ibwdt_ping(); + } + return count; +} + +static int +ibwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, + unsigned long arg) +{ + int new_margin; + 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 = "IB700 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: + ibwdt_ping(); + break; + + case WDIOC_SETTIMEOUT: + if (get_user(new_margin, p)) + return -EFAULT; + if (ibwdt_set_heartbeat(new_margin)) + return -EINVAL; + ibwdt_ping(); + /* Fall */ + + case WDIOC_GETTIMEOUT: + return put_user(wd_times[wd_margin], p); + + case WDIOC_SETOPTIONS: + { + int options, retval = -EINVAL; + + if (get_user(options, p)) + return -EFAULT; + + if (options & WDIOS_DISABLECARD) { + ibwdt_disable(); + retval = 0; + } + + if (options & WDIOS_ENABLECARD) { + ibwdt_ping(); + retval = 0; + } + + return retval; + } + + default: + return -ENOTTY; + } + return 0; +} + +static int +ibwdt_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(0, &ibwdt_is_open)) { + return -EBUSY; + } + if (nowayout) + __module_get(THIS_MODULE); + + /* Activate */ + ibwdt_ping(); + return nonseekable_open(inode, file); +} + +static int +ibwdt_close(struct inode *inode, struct file *file) +{ + if (expect_close == 42) { + ibwdt_disable(); + } else { + printk(KERN_CRIT PFX "WDT device closed unexpectedly. WDT will not stop!\n"); + ibwdt_ping(); + } + clear_bit(0, &ibwdt_is_open); + expect_close = 0; + return 0; +} + +/* + * Kernel Interfaces + */ + +static const struct file_operations ibwdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = ibwdt_write, + .ioctl = ibwdt_ioctl, + .open = ibwdt_open, + .release = ibwdt_close, +}; + +static struct miscdevice ibwdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &ibwdt_fops, +}; + +/* + * Init & exit routines + */ + +static int __devinit ibwdt_probe(struct platform_device *dev) +{ + int res; + + spin_lock_init(&ibwdt_lock); + +#if WDT_START != WDT_STOP + if (!request_region(WDT_STOP, 1, "IB700 WDT")) { + printk (KERN_ERR PFX "STOP method I/O %X is not available.\n", WDT_STOP); + res = -EIO; + goto out_nostopreg; + } +#endif + + if (!request_region(WDT_START, 1, "IB700 WDT")) { + printk (KERN_ERR PFX "START method I/O %X is not available.\n", WDT_START); + res = -EIO; + goto out_nostartreg; + } + + res = misc_register(&ibwdt_miscdev); + if (res) { + printk (KERN_ERR PFX "failed to register misc device\n"); + goto out_nomisc; + } + return 0; + +out_nomisc: + release_region(WDT_START, 1); +out_nostartreg: +#if WDT_START != WDT_STOP + release_region(WDT_STOP, 1); +#endif +out_nostopreg: + return res; +} + +static int __devexit ibwdt_remove(struct platform_device *dev) +{ + misc_deregister(&ibwdt_miscdev); + release_region(WDT_START,1); +#if WDT_START != WDT_STOP + release_region(WDT_STOP,1); +#endif + return 0; +} + +static void ibwdt_shutdown(struct platform_device *dev) +{ + /* Turn the WDT off if we have a soft shutdown */ + ibwdt_disable(); +} + +static struct platform_driver ibwdt_driver = { + .probe = ibwdt_probe, + .remove = __devexit_p(ibwdt_remove), + .shutdown = ibwdt_shutdown, + .driver = { + .owner = THIS_MODULE, + .name = DRV_NAME, + }, +}; + +static int __init ibwdt_init(void) +{ + int err; + + printk(KERN_INFO PFX "WDT driver for IB700 single board computer initialising.\n"); + + err = platform_driver_register(&ibwdt_driver); + if (err) + return err; + + ibwdt_platform_device = platform_device_register_simple(DRV_NAME, -1, NULL, 0); + if (IS_ERR(ibwdt_platform_device)) { + err = PTR_ERR(ibwdt_platform_device); + goto unreg_platform_driver; + } + + return 0; + +unreg_platform_driver: + platform_driver_unregister(&ibwdt_driver); + return err; +} + +static void __exit ibwdt_exit(void) +{ + platform_device_unregister(ibwdt_platform_device); + platform_driver_unregister(&ibwdt_driver); + printk(KERN_INFO PFX "Watchdog Module Unloaded.\n"); +} + +module_init(ibwdt_init); +module_exit(ibwdt_exit); + +MODULE_AUTHOR("Charles Howes <chowes@vsol.net>"); +MODULE_DESCRIPTION("IB700 SBC watchdog driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); + +/* end of ib700wdt.c */ |