| /* |
| * w83697hf/hg WDT driver |
| * |
| * (c) Copyright 2006 Samuel Tardieu <sam@rfc1149.net> |
| * (c) Copyright 2006 Marcus Junker <junker@anduras.de> |
| * |
| * Based on w83627hf_wdt.c which is based on advantechwdt.c |
| * which is based on wdt.c. |
| * Original copyright messages: |
| * |
| * (c) Copyright 2003 Pádraig Brady <P@draigBrady.com> |
| * |
| * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl> |
| * |
| * (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 Marcus Junker nor ANDURAS AG admit liability nor provide |
| * warranty for any of this software. This material is provided |
| * "AS-IS" and at no charge. |
| */ |
| |
| #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/notifier.h> |
| #include <linux/reboot.h> |
| #include <linux/init.h> |
| #include <linux/spinlock.h> |
| #include <linux/io.h> |
| #include <linux/uaccess.h> |
| |
| #include <asm/system.h> |
| |
| #define WATCHDOG_NAME "w83697hf/hg WDT" |
| #define PFX WATCHDOG_NAME ": " |
| #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ |
| #define WATCHDOG_EARLY_DISABLE 1 /* Disable until userland kicks in */ |
| |
| static unsigned long wdt_is_open; |
| static char expect_close; |
| static DEFINE_SPINLOCK(io_lock); |
| |
| /* You must set this - there is no sane way to probe for this board. */ |
| static int wdt_io = 0x2e; |
| module_param(wdt_io, int, 0); |
| MODULE_PARM_DESC(wdt_io, |
| "w83697hf/hg WDT io port (default 0x2e, 0 = autodetect)"); |
| |
| static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ |
| module_param(timeout, int, 0); |
| MODULE_PARM_DESC(timeout, |
| "Watchdog timeout in seconds. 1<= timeout <=255 (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) ")"); |
| |
| static int early_disable = WATCHDOG_EARLY_DISABLE; |
| module_param(early_disable, int, 0); |
| MODULE_PARM_DESC(early_disable, |
| "Watchdog gets disabled at boot time (default=" |
| __MODULE_STRING(WATCHDOG_EARLY_DISABLE) ")"); |
| |
| /* |
| * Kernel methods. |
| */ |
| |
| #define W83697HF_EFER (wdt_io + 0) /* Extended Function Enable Register */ |
| #define W83697HF_EFIR (wdt_io + 0) /* Extended Function Index Register |
| (same as EFER) */ |
| #define W83697HF_EFDR (wdt_io + 1) /* Extended Function Data Register */ |
| |
| static inline void w83697hf_unlock(void) |
| { |
| outb_p(0x87, W83697HF_EFER); /* Enter extended function mode */ |
| outb_p(0x87, W83697HF_EFER); /* Again according to manual */ |
| } |
| |
| static inline void w83697hf_lock(void) |
| { |
| outb_p(0xAA, W83697HF_EFER); /* Leave extended function mode */ |
| } |
| |
| /* |
| * The three functions w83697hf_get_reg(), w83697hf_set_reg() and |
| * w83697hf_write_timeout() must be called with the device unlocked. |
| */ |
| |
| static unsigned char w83697hf_get_reg(unsigned char reg) |
| { |
| outb_p(reg, W83697HF_EFIR); |
| return inb_p(W83697HF_EFDR); |
| } |
| |
| static void w83697hf_set_reg(unsigned char reg, unsigned char data) |
| { |
| outb_p(reg, W83697HF_EFIR); |
| outb_p(data, W83697HF_EFDR); |
| } |
| |
| static void w83697hf_write_timeout(int timeout) |
| { |
| /* Write Timeout counter to CRF4 */ |
| w83697hf_set_reg(0xF4, timeout); |
| } |
| |
| static void w83697hf_select_wdt(void) |
| { |
| w83697hf_unlock(); |
| w83697hf_set_reg(0x07, 0x08); /* Switch to logic device 8 (GPIO2) */ |
| } |
| |
| static inline void w83697hf_deselect_wdt(void) |
| { |
| w83697hf_lock(); |
| } |
| |
| static void w83697hf_init(void) |
| { |
| unsigned char bbuf; |
| |
| w83697hf_select_wdt(); |
| |
| bbuf = w83697hf_get_reg(0x29); |
| bbuf &= ~0x60; |
| bbuf |= 0x20; |
| |
| /* Set pin 119 to WDTO# mode (= CR29, WDT0) */ |
| w83697hf_set_reg(0x29, bbuf); |
| |
| bbuf = w83697hf_get_reg(0xF3); |
| bbuf &= ~0x04; |
| w83697hf_set_reg(0xF3, bbuf); /* Count mode is seconds */ |
| |
| w83697hf_deselect_wdt(); |
| } |
| |
| static void wdt_ping(void) |
| { |
| spin_lock(&io_lock); |
| w83697hf_select_wdt(); |
| |
| w83697hf_write_timeout(timeout); |
| |
| w83697hf_deselect_wdt(); |
| spin_unlock(&io_lock); |
| } |
| |
| static void wdt_enable(void) |
| { |
| spin_lock(&io_lock); |
| w83697hf_select_wdt(); |
| |
| w83697hf_write_timeout(timeout); |
| w83697hf_set_reg(0x30, 1); /* Enable timer */ |
| |
| w83697hf_deselect_wdt(); |
| spin_unlock(&io_lock); |
| } |
| |
| static void wdt_disable(void) |
| { |
| spin_lock(&io_lock); |
| w83697hf_select_wdt(); |
| |
| w83697hf_set_reg(0x30, 0); /* Disable timer */ |
| w83697hf_write_timeout(0); |
| |
| w83697hf_deselect_wdt(); |
| spin_unlock(&io_lock); |
| } |
| |
| static unsigned char wdt_running(void) |
| { |
| unsigned char t; |
| |
| spin_lock(&io_lock); |
| w83697hf_select_wdt(); |
| |
| t = w83697hf_get_reg(0xF4); /* Read timer */ |
| |
| w83697hf_deselect_wdt(); |
| spin_unlock(&io_lock); |
| |
| return t; |
| } |
| |
| static int wdt_set_heartbeat(int t) |
| { |
| if (t < 1 || t > 255) |
| return -EINVAL; |
| |
| timeout = t; |
| return 0; |
| } |
| |
| static ssize_t wdt_write(struct file *file, const char __user *buf, |
| size_t count, loff_t *ppos) |
| { |
| if (count) { |
| if (!nowayout) { |
| size_t i; |
| |
| 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; |
| } |
| } |
| wdt_ping(); |
| } |
| return count; |
| } |
| |
| static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
| { |
| void __user *argp = (void __user *)arg; |
| int __user *p = argp; |
| int new_timeout; |
| static const struct watchdog_info ident = { |
| .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
| | WDIOF_MAGICCLOSE, |
| .firmware_version = 1, |
| .identity = "W83697HF 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_SETOPTIONS: |
| { |
| int options, retval = -EINVAL; |
| |
| if (get_user(options, p)) |
| return -EFAULT; |
| |
| if (options & WDIOS_DISABLECARD) { |
| wdt_disable(); |
| retval = 0; |
| } |
| |
| if (options & WDIOS_ENABLECARD) { |
| wdt_enable(); |
| retval = 0; |
| } |
| |
| return retval; |
| } |
| |
| case WDIOC_KEEPALIVE: |
| wdt_ping(); |
| break; |
| |
| case WDIOC_SETTIMEOUT: |
| if (get_user(new_timeout, p)) |
| return -EFAULT; |
| if (wdt_set_heartbeat(new_timeout)) |
| return -EINVAL; |
| wdt_ping(); |
| /* Fall */ |
| |
| case WDIOC_GETTIMEOUT: |
| return put_user(timeout, p); |
| |
| default: |
| return -ENOTTY; |
| } |
| return 0; |
| } |
| |
| static int wdt_open(struct inode *inode, struct file *file) |
| { |
| if (test_and_set_bit(0, &wdt_is_open)) |
| return -EBUSY; |
| /* |
| * Activate |
| */ |
| |
| wdt_enable(); |
| return nonseekable_open(inode, file); |
| } |
| |
| static int wdt_close(struct inode *inode, struct file *file) |
| { |
| if (expect_close == 42) |
| wdt_disable(); |
| else { |
| printk(KERN_CRIT PFX |
| "Unexpected close, not stopping watchdog!\n"); |
| wdt_ping(); |
| } |
| expect_close = 0; |
| clear_bit(0, &wdt_is_open); |
| return 0; |
| } |
| |
| /* |
| * Notifier for system down |
| */ |
| |
| static int wdt_notify_sys(struct notifier_block *this, unsigned long code, |
| void *unused) |
| { |
| if (code == SYS_DOWN || code == SYS_HALT) { |
| /* Turn the WDT off */ |
| wdt_disable(); |
| } |
| return NOTIFY_DONE; |
| } |
| |
| /* |
| * Kernel Interfaces |
| */ |
| |
| static const struct file_operations wdt_fops = { |
| .owner = THIS_MODULE, |
| .llseek = no_llseek, |
| .write = wdt_write, |
| .unlocked_ioctl = wdt_ioctl, |
| .open = wdt_open, |
| .release = wdt_close, |
| }; |
| |
| static struct miscdevice wdt_miscdev = { |
| .minor = WATCHDOG_MINOR, |
| .name = "watchdog", |
| .fops = &wdt_fops, |
| }; |
| |
| /* |
| * The WDT needs to learn about soft shutdowns in order to |
| * turn the timebomb registers off. |
| */ |
| |
| static struct notifier_block wdt_notifier = { |
| .notifier_call = wdt_notify_sys, |
| }; |
| |
| static int w83697hf_check_wdt(void) |
| { |
| if (!request_region(wdt_io, 2, WATCHDOG_NAME)) { |
| printk(KERN_ERR PFX |
| "I/O address 0x%x already in use\n", wdt_io); |
| return -EIO; |
| } |
| |
| printk(KERN_DEBUG PFX |
| "Looking for watchdog at address 0x%x\n", wdt_io); |
| w83697hf_unlock(); |
| if (w83697hf_get_reg(0x20) == 0x60) { |
| printk(KERN_INFO PFX |
| "watchdog found at address 0x%x\n", wdt_io); |
| w83697hf_lock(); |
| return 0; |
| } |
| /* Reprotect in case it was a compatible device */ |
| w83697hf_lock(); |
| |
| printk(KERN_INFO PFX "watchdog not found at address 0x%x\n", wdt_io); |
| release_region(wdt_io, 2); |
| return -EIO; |
| } |
| |
| static int w83697hf_ioports[] = { 0x2e, 0x4e, 0x00 }; |
| |
| static int __init wdt_init(void) |
| { |
| int ret, i, found = 0; |
| |
| printk(KERN_INFO PFX "WDT driver for W83697HF/HG initializing\n"); |
| |
| if (wdt_io == 0) { |
| /* we will autodetect the W83697HF/HG watchdog */ |
| for (i = 0; ((!found) && (w83697hf_ioports[i] != 0)); i++) { |
| wdt_io = w83697hf_ioports[i]; |
| if (!w83697hf_check_wdt()) |
| found++; |
| } |
| } else { |
| if (!w83697hf_check_wdt()) |
| found++; |
| } |
| |
| if (!found) { |
| printk(KERN_ERR PFX "No W83697HF/HG could be found\n"); |
| ret = -EIO; |
| goto out; |
| } |
| |
| w83697hf_init(); |
| if (early_disable) { |
| if (wdt_running()) |
| printk (KERN_WARNING PFX "Stopping previously enabled watchdog until userland kicks in\n"); |
| wdt_disable(); |
| } |
| |
| if (wdt_set_heartbeat(timeout)) { |
| wdt_set_heartbeat(WATCHDOG_TIMEOUT); |
| printk(KERN_INFO PFX |
| "timeout value must be 1 <= timeout <= 255, using %d\n", |
| WATCHDOG_TIMEOUT); |
| } |
| |
| ret = register_reboot_notifier(&wdt_notifier); |
| if (ret != 0) { |
| printk(KERN_ERR PFX |
| "cannot register reboot notifier (err=%d)\n", ret); |
| goto unreg_regions; |
| } |
| |
| ret = misc_register(&wdt_miscdev); |
| if (ret != 0) { |
| printk(KERN_ERR PFX |
| "cannot register miscdev on minor=%d (err=%d)\n", |
| WATCHDOG_MINOR, ret); |
| goto unreg_reboot; |
| } |
| |
| printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", |
| timeout, nowayout); |
| |
| out: |
| return ret; |
| unreg_reboot: |
| unregister_reboot_notifier(&wdt_notifier); |
| unreg_regions: |
| release_region(wdt_io, 2); |
| goto out; |
| } |
| |
| static void __exit wdt_exit(void) |
| { |
| misc_deregister(&wdt_miscdev); |
| unregister_reboot_notifier(&wdt_notifier); |
| release_region(wdt_io, 2); |
| } |
| |
| module_init(wdt_init); |
| module_exit(wdt_exit); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Marcus Junker <junker@anduras.de>, Samuel Tardieu <sam@rfc1149.net>"); |
| MODULE_DESCRIPTION("w83697hf/hg WDT driver"); |
| MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |