diff options
Diffstat (limited to 'drivers/char/watchdog/sbc8360.c')
| -rw-r--r-- | drivers/char/watchdog/sbc8360.c | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/drivers/char/watchdog/sbc8360.c b/drivers/char/watchdog/sbc8360.c new file mode 100644 index 000000000000..c6cbf808d8c2 --- /dev/null +++ b/drivers/char/watchdog/sbc8360.c @@ -0,0 +1,414 @@ +/* + * SBC8360 Watchdog driver + * + * (c) Copyright 2005 Webcon, Inc. + * + * Based on ib700wdt.c, which is based on advantechwdt.c which is based + * on acquirewdt.c which is based on wdt.c. + * + * (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/config.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/miscdevice.h> +#include <linux/watchdog.h> +#include <linux/ioport.h> +#include <linux/delay.h> +#include <linux/notifier.h> +#include <linux/fs.h> +#include <linux/reboot.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/moduleparam.h> + +#include <asm/io.h> +#include <asm/uaccess.h> +#include <asm/system.h> + +static unsigned long sbc8360_is_open; +static spinlock_t sbc8360_lock; +static char expect_close; + +#define PFX "sbc8360: " + +/* + * + * Watchdog Timer Configuration + * + * The function of the watchdog timer is to reset the system automatically + * and is defined at I/O port 0120H and 0121H. To enable the watchdog timer + * and allow the system to reset, write appropriate values from the table + * below to I/O port 0120H and 0121H. To disable the timer, write a zero + * value to I/O port 0121H for the system to stop the watchdog function. + * + * The following describes how the timer should be programmed (according to + * the vendor documentation) + * + * Enabling Watchdog: + * MOV AX,000AH (enable, phase I) + * MOV DX,0120H + * OUT DX,AX + * MOV AX,000BH (enable, phase II) + * MOV DX,0120H + * OUT DX,AX + * MOV AX,000nH (set multiplier n, from 1-4) + * MOV DX,0120H + * OUT DX,AX + * MOV AX,000mH (set base timer m, from 0-F) + * MOV DX,0121H + * OUT DX,AX + * + * Reset timer: + * MOV AX,000mH (same as set base timer, above) + * MOV DX,0121H + * OUT DX,AX + * + * Disabling Watchdog: + * MOV AX,0000H (a zero value) + * MOV DX,0120H + * OUT DX,AX + * + * Watchdog timeout configuration values: + * N + * M | 1 2 3 4 + * --|---------------------------------- + * 0 | 0.5s 5s 50s 100s + * 1 | 1s 10s 100s 200s + * 2 | 1.5s 15s 150s 300s + * 3 | 2s 20s 200s 400s + * 4 | 2.5s 25s 250s 500s + * 5 | 3s 30s 300s 600s + * 6 | 3.5s 35s 350s 700s + * 7 | 4s 40s 400s 800s + * 8 | 4.5s 45s 450s 900s + * 9 | 5s 50s 500s 1000s + * A | 5.5s 55s 550s 1100s + * B | 6s 60s 600s 1200s + * C | 6.5s 65s 650s 1300s + * D | 7s 70s 700s 1400s + * E | 7.5s 75s 750s 1500s + * F | 8s 80s 800s 1600s + * + * Another way to say the same things is: + * For N=1, Timeout = (M+1) * 0.5s + * For N=2, Timeout = (M+1) * 5s + * For N=3, Timeout = (M+1) * 50s + * For N=4, Timeout = (M+1) * 100s + * + */ + +static int wd_times[64][2] = { + {0, 1}, /* 0 = 0.5s */ + {1, 1}, /* 1 = 1s */ + {2, 1}, /* 2 = 1.5s */ + {3, 1}, /* 3 = 2s */ + {4, 1}, /* 4 = 2.5s */ + {5, 1}, /* 5 = 3s */ + {6, 1}, /* 6 = 3.5s */ + {7, 1}, /* 7 = 4s */ + {8, 1}, /* 8 = 4.5s */ + {9, 1}, /* 9 = 5s */ + {0xA, 1}, /* 10 = 5.5s */ + {0xB, 1}, /* 11 = 6s */ + {0xC, 1}, /* 12 = 6.5s */ + {0xD, 1}, /* 13 = 7s */ + {0xE, 1}, /* 14 = 7.5s */ + {0xF, 1}, /* 15 = 8s */ + {0, 2}, /* 16 = 5s */ + {1, 2}, /* 17 = 10s */ + {2, 2}, /* 18 = 15s */ + {3, 2}, /* 19 = 20s */ + {4, 2}, /* 20 = 25s */ + {5, 2}, /* 21 = 30s */ + {6, 2}, /* 22 = 35s */ + {7, 2}, /* 23 = 40s */ + {8, 2}, /* 24 = 45s */ + {9, 2}, /* 25 = 50s */ + {0xA, 2}, /* 26 = 55s */ + {0xB, 2}, /* 27 = 60s */ + {0xC, 2}, /* 28 = 65s */ + {0xD, 2}, /* 29 = 70s */ + {0xE, 2}, /* 30 = 75s */ + {0xF, 2}, /* 31 = 80s */ + {0, 3}, /* 32 = 50s */ + {1, 3}, /* 33 = 100s */ + {2, 3}, /* 34 = 150s */ + {3, 3}, /* 35 = 200s */ + {4, 3}, /* 36 = 250s */ + {5, 3}, /* 37 = 300s */ + {6, 3}, /* 38 = 350s */ + {7, 3}, /* 39 = 400s */ + {8, 3}, /* 40 = 450s */ + {9, 3}, /* 41 = 500s */ + {0xA, 3}, /* 42 = 550s */ + {0xB, 3}, /* 43 = 600s */ + {0xC, 3}, /* 44 = 650s */ + {0xD, 3}, /* 45 = 700s */ + {0xE, 3}, /* 46 = 750s */ + {0xF, 3}, /* 47 = 800s */ + {0, 4}, /* 48 = 100s */ + {1, 4}, /* 49 = 200s */ + {2, 4}, /* 50 = 300s */ + {3, 4}, /* 51 = 400s */ + {4, 4}, /* 52 = 500s */ + {5, 4}, /* 53 = 600s */ + {6, 4}, /* 54 = 700s */ + {7, 4}, /* 55 = 800s */ + {8, 4}, /* 56 = 900s */ + {9, 4}, /* 57 = 1000s */ + {0xA, 4}, /* 58 = 1100s */ + {0xB, 4}, /* 59 = 1200s */ + {0xC, 4}, /* 60 = 1300s */ + {0xD, 4}, /* 61 = 1400s */ + {0xE, 4}, /* 62 = 1500s */ + {0xF, 4} /* 63 = 1600s */ +}; + +#define SBC8360_ENABLE 0x120 +#define SBC8360_BASETIME 0x121 + +static int timeout = 27; +static int wd_margin = 0xB; +static int wd_multiplier = 2; +static int nowayout = WATCHDOG_NOWAYOUT; + +module_param(timeout, int, 27); +MODULE_PARM_DESC(timeout, "Index into timeout table (0-63) (default=27 (60s))"); +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, + "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); + +/* + * Kernel methods. + */ + +/* Activate and pre-configure watchdog */ +static void sbc8360_activate(void) +{ + /* Enable the watchdog */ + outb(0x0A, SBC8360_ENABLE); + msleep_interruptible(100); + outb(0x0B, SBC8360_ENABLE); + msleep_interruptible(100); + /* Set timeout multiplier */ + outb(wd_multiplier, SBC8360_ENABLE); + msleep_interruptible(100); + /* Nothing happens until first sbc8360_ping() */ +} + +/* Kernel pings watchdog */ +static void sbc8360_ping(void) +{ + /* Write the base timer register */ + outb(wd_margin, SBC8360_BASETIME); +} + +/* Userspace pings kernel driver, or requests clean close */ +static ssize_t sbc8360_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; + } + } + sbc8360_ping(); + } + return count; +} + +static int sbc8360_open(struct inode *inode, struct file *file) +{ + spin_lock(&sbc8360_lock); + if (test_and_set_bit(0, &sbc8360_is_open)) { + spin_unlock(&sbc8360_lock); + return -EBUSY; + } + if (nowayout) + __module_get(THIS_MODULE); + + /* Activate and ping once to start the countdown */ + spin_unlock(&sbc8360_lock); + sbc8360_activate(); + sbc8360_ping(); + return nonseekable_open(inode, file); +} + +static int sbc8360_close(struct inode *inode, struct file *file) +{ + spin_lock(&sbc8360_lock); + if (expect_close == 42) + outb(0, SBC8360_ENABLE); + else + printk(KERN_CRIT PFX + "SBC8360 device closed unexpectedly. SBC8360 will not stop!\n"); + + clear_bit(0, &sbc8360_is_open); + expect_close = 0; + spin_unlock(&sbc8360_lock); + return 0; +} + +/* + * Notifier for system down + */ + +static int sbc8360_notify_sys(struct notifier_block *this, unsigned long code, + void *unused) +{ + if (code == SYS_DOWN || code == SYS_HALT) { + /* Disable the SBC8360 Watchdog */ + outb(0, SBC8360_ENABLE); + } + return NOTIFY_DONE; +} + +/* + * Kernel Interfaces + */ + +static struct file_operations sbc8360_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = sbc8360_write, + .open = sbc8360_open, + .release = sbc8360_close, +}; + +static struct miscdevice sbc8360_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &sbc8360_fops, +}; + +/* + * The SBC8360 needs to learn about soft shutdowns in order to + * turn the timebomb registers off. + */ + +static struct notifier_block sbc8360_notifier = { + .notifier_call = sbc8360_notify_sys, +}; + +static int __init sbc8360_init(void) +{ + int res; + unsigned long int mseconds = 60000; + + spin_lock_init(&sbc8360_lock); + res = misc_register(&sbc8360_miscdev); + if (res) { + printk(KERN_ERR PFX "failed to register misc device\n"); + goto out_nomisc; + } + + if (!request_region(SBC8360_ENABLE, 1, "SBC8360")) { + printk(KERN_ERR PFX "ENABLE method I/O %X is not available.\n", + SBC8360_ENABLE); + res = -EIO; + goto out_noenablereg; + } + if (!request_region(SBC8360_BASETIME, 1, "SBC8360")) { + printk(KERN_ERR PFX + "BASETIME method I/O %X is not available.\n", + SBC8360_BASETIME); + res = -EIO; + goto out_nobasetimereg; + } + + res = register_reboot_notifier(&sbc8360_notifier); + if (res) { + printk(KERN_ERR PFX "Failed to register reboot notifier.\n"); + goto out_noreboot; + } + + if (timeout < 0 || timeout > 63) { + printk(KERN_ERR PFX "Invalid timeout index (must be 0-63).\n"); + res = -EINVAL; + goto out_noreboot; + } + + wd_margin = wd_times[timeout][0]; + wd_multiplier = wd_times[timeout][1]; + + if (wd_multiplier == 1) + mseconds = (wd_margin + 1) * 500; + else if (wd_multiplier == 2) + mseconds = (wd_margin + 1) * 5000; + else if (wd_multiplier == 3) + mseconds = (wd_margin + 1) * 50000; + else if (wd_multiplier == 4) + mseconds = (wd_margin + 1) * 100000; + + /* My kingdom for the ability to print "0.5 seconds" in the kernel! */ + printk(KERN_INFO PFX "Timeout set at %ld ms.\n", mseconds); + + return 0; + + out_noreboot: + release_region(SBC8360_ENABLE, 1); + release_region(SBC8360_BASETIME, 1); + out_noenablereg: + out_nobasetimereg: + misc_deregister(&sbc8360_miscdev); + out_nomisc: + return res; +} + +static void __exit sbc8360_exit(void) +{ + misc_deregister(&sbc8360_miscdev); + unregister_reboot_notifier(&sbc8360_notifier); + release_region(SBC8360_ENABLE, 1); + release_region(SBC8360_BASETIME, 1); +} + +module_init(sbc8360_init); +module_exit(sbc8360_exit); + +MODULE_AUTHOR("Ian E. Morgan <imorgan@webcon.ca>"); +MODULE_DESCRIPTION("SBC8360 watchdog driver"); +MODULE_LICENSE("GPL"); +MODULE_VERSION("1.0"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); + +/* end of sbc8360.c */ |
