Messages in this thread | | | Date | Thu, 21 Feb 2002 07:54:43 +0200 (SAST) | From | Zwane Mwaikambo <> | Subject | [DRIVER][RFC] SC1200 Watchdog driver |
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Roy, careful what you wish for ;) Mind you i don't have this device, but the basic framework is there that if i missed something, it should be pretty trivial to fix. One thing to note is that the SC1200 is based on the PC87307/PC97307 which is a PnP device, however this driver requires an io parameter, but i'll add the PnP support if the driver has a chance of living.
Cheers, Zwane Mwaikambo
/* * National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver * (c) Copyright 2002 Zwane Mwaikambo <zwane@commfireservices.com>, * All Rights Reserved. * Based on wdt.c and wdt977.c by Alan Cox and Woody Suwalski respectively. * * 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. * * The author(s) of this software shall not be held liable for damages * of any nature resulting due to the use of this software. This * software is provided AS-IS with no warranties. * * Changelog: * 20020220 Zwane Mwaikambo Code based on datasheet, no hardware. */
#include <linux/config.h> #include <linux/module.h> #include <linux/version.h> #include <linux/types.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/sched.h> #include <linux/smp_lock.h> #include <linux/miscdevice.h> #include <linux/watchdog.h> #include <linux/slab.h> #include <linux/ioport.h> #include <linux/fcntl.h> #include <asm/semaphore.h> #include <asm/io.h> #include <asm/uaccess.h> #include <asm/system.h> #include <linux/notifier.h> #include <linux/reboot.h> #include <linux/init.h>
#define SC1200_MODULE_VER "build 20020220" #define SC1200_MODULE_NAME "sc1200wdt" #define PFX SC1200_MODULE_NAME ": "
#define PMIR (io) /* Power Management Index Register */ #define PMDR (io+1) /* Power Management Data Register */
/* Data Register indexes */ #define FER1 0x00 /* Function enable register 1 */ #define FER2 0x01 /* Function enable register 2 */ #define PMC1 0x02 /* Power Management Ctrl 1 */ #define PMC2 0x03 /* Power Management Ctrl 2 */ #define PMC3 0x04 /* Power Management Ctrl 3 */ #define WDTO 0x05 /* Watchdog timeout register */ #define WDCF 0x06 /* Watchdog config register */ #define WDST 0x07 /* Watchdog status register */
/* WDO Status */ #define WDO_ENABLED 0x00 #define WDO_DISABLED 0x01
/* WDCF bitfields - which devices assert WDO */ #define KBC_IRQ 0x01 /* Keyboard Controller */ #define MSE_IRQ 0x02 /* Mouse */ #define UART1_IRQ 0x03 /* Serial0 */ #define UART2_IRQ 0x04 /* Serial1 */ /* 5 -7 are reserved */
static char banner[] __initdata = KERN_INFO PFX SC1200_MODULE_VER " timeout = %d min(s)\n"; static int timeout = 1; /* default to 1 minute (0 - 255), 0 disables it */ static int io; struct semaphore open_sem;
MODULE_PARM(io, "i"); MODULE_PARM_DESC(io, "io port"); MODULE_PARM(timeout, "i"); MODULE_PARM_DESC(timeout, "range is (0-255), default is 1");
/* Read from Data Register */ static inline void sc1200wdt_read_data(unsigned char index, unsigned char *data) { outb_p(index, PMIR); *data = inb(PMDR); }
/* Write to Data Register */ static inline void sc1200wdt_write_data(unsigned char index, unsigned char data) { outb_p(index, PMIR); outb(data, PMDR); }
/* this returns the status of the WDO signal, inactive high * WDO_ENABLED or WDO_DISABLED */ static int sc1200wdt_status(void) { unsigned char ret;
sc1200wdt_read_data(WDST, &ret); return (ret & 0x01); /* bits 1 - 7 are undefined */ }
static int sc1200wdt_open(struct inode *inode, struct file *file) { unsigned char reg;
/* allow one at a time */ if (down_trylock(&open_sem)) return -EBUSY;
MOD_INC_USE_COUNT;
if (timeout > 255) timeout = 255;
sc1200wdt_read_data(WDCF, ®); /* assert WDO when any of the following interrupts are triggered too */ reg |= (KBC_IRQ | MSE_IRQ | UART1_IRQ | UART2_IRQ); sc1200wdt_write_data(WDCF, reg); /* set the timeout and get the ball rolling */ sc1200wdt_write_data(WDTO, timeout); printk(KERN_INFO PFX "Watchdog enabled"); return 0; }
static int sc1200wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { int new_timeout; static struct watchdog_info ident = { WDIOF_SETTIMEOUT, 0, "PC87307/PC97307" };
switch (cmd) { default: return -ENOTTY; /* Keep Pavel Machek amused ;) */
case WDIOC_GETSUPPORT: if (copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident))) return -EFAULT; return 0;
case WDIOC_GETSTATUS: return put_user(sc1200wdt_status(), (int *)arg); case WDIOC_KEEPALIVE: sc1200wdt_write_data(WDTO, timeout); return 0;
case WDIOC_SETTIMEOUT: if (get_user(new_timeout, (int *)arg)) return -EFAULT; if (new_timeout < 0 || new_timeout > 255) return -EINVAL; timeout = new_timeout; sc1200wdt_write_data(WDTO, timeout); /* fall through */
case WDIOC_GETTIMEOUT: return put_user(timeout, (int *)arg); } }
static int sc1200wdt_release(struct inode *inode, struct file *file) { lock_kernel();
/* Disable it on the way out */ sc1200wdt_write_data(WDTO, 0); up(&open_sem);
unlock_kernel();
printk(KERN_INFO PFX "Watchdog disabled\n"); MOD_DEC_USE_COUNT;
return 0; }
static ssize_t sc1200wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) { if (ppos != &file->f_pos) return -ESPIPE;
if (len) { sc1200wdt_write_data(WDTO, timeout); return 1; } return 0; }
static int sc1200wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { if (code == SYS_DOWN || code == SYS_HALT) sc1200wdt_write_data(WDTO, 0);
return NOTIFY_DONE; }
static struct notifier_block sc1200wdt_notifier = { sc1200wdt_notify_sys, NULL, 0 };
#ifndef MODULE static int __init sc1200wdt_setup(char *str) { int ints[4];
str = get_options (str, ARRAY_SIZE(ints), ints);
if (ints[0] > 0) { io = ints[1]; if (ints[0] > 1) timeout = ints[2]; }
return 1; }
__setup("sc1200wdt=", sc1200wdt_setup); #endif /* MODULE */
static struct file_operations sc1200wdt_fops = { owner: THIS_MODULE, write: sc1200wdt_write, ioctl: sc1200wdt_ioctl, open: sc1200wdt_open, release: sc1200wdt_release, };
static struct miscdevice sc1200wdt_miscdev = { WATCHDOG_MINOR, "watchdog", &sc1200wdt_fops };
static int __init sc1200wdt_probe(int base_io) { /* How can we probe for this thing? */ return 0; }
static int __init sc1200wdt_init(void) { int ret;
printk(banner, timeout); if (!request_region(io, 2, SC1200_MODULE_NAME)) { printk(KERN_ERR PFX "IO port %#x not free.\n", io); ret = -EBUSY; goto out_clean; }
ret = sc1200wdt_probe(io); if (ret == -ENODEV) goto out_io;
ret = register_reboot_notifier(&sc1200wdt_notifier); if (ret) { printk(KERN_ERR PFX "Unable to register reboot notifier err = %d\n", ret); goto out_io; }
sema_init(&open_sem, 1); ret = misc_register(&sc1200wdt_miscdev); if (ret) { printk(KERN_ERR PFX "Unable to register miscdev on minor %d\n", WATCHDOG_MINOR); goto out_rbt; }
out_clean: return ret;
out_rbt: unregister_reboot_notifier(&sc1200wdt_notifier); out_io: release_region(io, 2); goto out_clean; }
static void __exit sc1200wdt_exit(void) { misc_deregister(&sc1200wdt_miscdev); unregister_reboot_notifier(&sc1200wdt_notifier); release_region(io, 2); }
module_init(sc1200wdt_init); module_exit(sc1200wdt_exit);
MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>"); MODULE_DESCRIPTION("Driver for National Semiconductor PC87307/PC97307 watchdog component"); MODULE_LICENSE("GPL"); EXPORT_NO_SYMBOLS;
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