diff options
Diffstat (limited to 'drivers/char/wdt977.c')
| -rw-r--r-- | drivers/char/wdt977.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/drivers/char/wdt977.c b/drivers/char/wdt977.c new file mode 100644 index 000000000..c45e63d60 --- /dev/null +++ b/drivers/char/wdt977.c @@ -0,0 +1,204 @@ +/* + * Wdt977 0.01: A Watchdog Device for Netwinder W83977AF chip + * + * (c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>) + * + * ----------------------- + * + * 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. + * + * ----------------------- + */ + +#include <linux/module.h> +#include <linux/config.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/miscdevice.h> +#include <linux/init.h> + +#include <asm/io.h> +#include <asm/system.h> + +#define WATCHDOG_MINOR 130 + +static int timeout = 3; +static int timer_alive = 0; +static int testmode = 0; + +/* + * Allow only one person to hold it open + */ + +static int wdt977_open(struct inode *inode, struct file *file) +{ + if(timer_alive) + return -EBUSY; + MOD_INC_USE_COUNT; + timer_alive++; + + //max timeout value = 255 minutes (0xFF). Write 0 to disable WatchDog. + if (timeout>255) + timeout = 255; + + printk(KERN_INFO "Watchdog: active, current timeout %d min.\n",timeout); + + // unlock the SuperIO chip + outb(0x87,0x370); + outb(0x87,0x370); + + //select device Aux2 (device=8) and set watchdog regs F2, F3 and F4 + //F2 has the timeout in minutes + //F3 could be set to the POWER LED blink (with GP17 set to PowerLed) + // at timeout, and to reset timer on kbd/mouse activity (not now) + //F4 is used to just clear the TIMEOUT'ed state (bit 0) + + outb(0x07,0x370); + outb(0x08,0x371); + outb(0xF2,0x370); + outb(timeout,0x371); + outb(0xF3,0x370); + outb(0x00,0x371); //another setting is 0E for kbd/mouse/LED + outb(0xF4,0x370); + outb(0x00,0x371); + + //at last select device Aux1 (dev=7) and set GP16 as a watchdog output + if (!testmode) + { + outb(0x07,0x370); + outb(0x07,0x371); + outb(0xE6,0x370); + outb(0x08,0x371); + } + + // lock the SuperIO chip + outb(0xAA,0x370); + + return 0; +} + +static int wdt977_release(struct inode *inode, struct file *file) +{ + /* + * Shut off the timer. + * Lock it in if it's a module and we defined ...NOWAYOUT + */ +#ifndef CONFIG_WATCHDOG_NOWAYOUT + + // unlock the SuperIO chip + outb(0x87,0x370); + outb(0x87,0x370); + + //select device Aux2 (device=8) and set watchdog regs F2,F3 and F4 + //F3 is reset to its default state + //F4 can clear the TIMEOUT'ed state (bit 0) - back to default + //We can not use GP17 as a PowerLed, as we use its usage as a RedLed + + outb(0x07,0x370); + outb(0x08,0x371); + outb(0xF2,0x370); + outb(0xFF,0x371); + outb(0xF3,0x370); + outb(0x00,0x371); + outb(0xF4,0x370); + outb(0x00,0x371); + outb(0xF2,0x370); + outb(0x00,0x371); + + //at last select device Aux1 (dev=7) and set GP16 as a watchdog output + outb(0x07,0x370); + outb(0x07,0x371); + outb(0xE6,0x370); + outb(0x08,0x371); + + // lock the SuperIO chip + outb(0xAA,0x370); + + MOD_DEC_USE_COUNT; + timer_alive=0; + + printk(KERN_INFO "Watchdog: shutdown.\n"); +#endif + return 0; +} + +static ssize_t wdt977_write(struct file *file, const char *data, size_t len, loff_t *ppos) +{ + + //max timeout value = 255 minutes (0xFF). Write 0 to disable WatchDog. + if (timeout>255) + timeout = 255; + + /* + * Refresh the timer. + */ + + //we have a hw bug somewhere, so each 977 minute is actually only 30sec + //as such limit the max timeout to half of max of 255 minutes... +// if (timeout>126) +// timeout = 126; + + // unlock the SuperIO chip + outb(0x87,0x370); + outb(0x87,0x370); + + //select device Aux2 (device=8) and kicks watchdog reg F2 + //F2 has the timeout in minutes + + outb(0x07,0x370); + outb(0x08,0x371); + outb(0xF2,0x370); + outb(timeout,0x371); + + // lock the SuperIO chip + outb(0xAA,0x370); + + return 1; +} + +static struct file_operations wdt977_fops= +{ + NULL, /* Seek */ + NULL, /* Read */ + wdt977_write, /* Write */ + NULL, /* Readdir */ + NULL, /* Select */ + NULL, /* Ioctl */ + NULL, /* MMap */ + wdt977_open, + NULL, /* flush */ + wdt977_release, + NULL, + NULL /* Fasync */ +}; + +static struct miscdevice wdt977_miscdev= +{ + WATCHDOG_MINOR, + "watchdog", + &wdt977_fops +}; + +static int __init nwwatchdog_init(void) +{ + if (!machine_is_netwinder()) + return -ENODEV; + + misc_register(&wdt977_miscdev); + printk(KERN_INFO "NetWinder Watchdog sleeping.\n"); + return 0; +} + +static void __exit nwwatchdog_exit(void) +{ + misc_deregister(&wdt977_miscdev); +} + +EXPORT_NO_SYMBOLS; + +module_init(nwwatchdog_init); +module_exit(nwwatchdog_exit); |