/* $Id: riowatchdog.c,v 1.3 2001/10/08 22:19:51 davem Exp $ * riowatchdog.c - driver for hw watchdog inside Super I/O of RIO * * Copyright (C) 2001 David S. Miller (davem@redhat.com) */ #include #include #include #include #include #include #include #include #include #include #include #include #include /* RIO uses the NatSemi Super I/O power management logical device * as its' watchdog. * * When the watchdog triggers, it asserts a line to the BBC (Boot Bus * Controller) of the machine. The BBC can only be configured to * trigger a power-on reset when the signal is asserted. The BBC * can be configured to ignore the signal entirely as well. * * The only Super I/O device register we care about is at index * 0x05 (WDTO_INDEX) which is the watchdog time-out in minutes (1-255). * If set to zero, this disables the watchdog. When set, the system * must periodically (before watchdog expires) clear (set to zero) and * re-set the watchdog else it will trigger. * * There are two other indexed watchdog registers inside this Super I/O * logical device, but they are unused. The first, at index 0x06 is * the watchdog control and can be used to make the watchdog timer re-set * when the PS/2 mouse or serial lines show activity. The second, at * index 0x07 is merely a sampling of the line from the watchdog to the * BBC. * * The watchdog device generates no interrupts. */ MODULE_AUTHOR("David S. Miller "); MODULE_DESCRIPTION("Hardware watchdog driver for Sun RIO"); MODULE_SUPPORTED_DEVICE("watchdog"); MODULE_LICENSE("GPL"); #define RIOWD_NAME "pmc" #define RIOWD_MINOR 215 static spinlock_t riowd_lock = SPIN_LOCK_UNLOCKED; static void *bbc_regs; static void *riowd_regs; #define WDTO_INDEX 0x05 static int riowd_timeout = 1; /* in minutes */ MODULE_PARM(riowd_timeout,"i"); MODULE_PARM_DESC(riowd_timeout, "Watchdog timeout in minutes"); #if 0 /* Currently unused. */ static u8 riowd_readreg(int index) { unsigned long flags; u8 ret; spin_lock_irqsave(&riowd_lock, flags); writeb(index, riowd_regs + 0); ret = readb(riowd_regs + 1); spin_unlock_irqrestore(&riowd_lock, flags); return ret; } #endif static void riowd_writereg(u8 val, int index) { unsigned long flags; spin_lock_irqsave(&riowd_lock, flags); writeb(index, riowd_regs + 0); writeb(val, riowd_regs + 1); spin_unlock_irqrestore(&riowd_lock, flags); } static void riowd_pingtimer(void) { riowd_writereg(riowd_timeout, WDTO_INDEX); } static void riowd_stoptimer(void) { u8 val; riowd_writereg(0, WDTO_INDEX); val = readb(bbc_regs + BBC_WDACTION); val &= ~BBC_WDACTION_RST; writeb(val, bbc_regs + BBC_WDACTION); } static void riowd_starttimer(void) { u8 val; riowd_writereg(riowd_timeout, WDTO_INDEX); val = readb(bbc_regs + BBC_WDACTION); val |= BBC_WDACTION_RST; writeb(val, bbc_regs + BBC_WDACTION); } static int riowd_open(struct inode *inode, struct file *filp) { return 0; } static int riowd_release(struct inode *inode, struct file *filp) { return 0; } static int riowd_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) { static struct watchdog_info info = { 0, 0, "Natl. Semiconductor PC97317" }; unsigned int options; switch (cmd) { case WDIOC_GETSUPPORT: if (copy_to_user((struct watchdog_info *) arg, &info, sizeof(info))) return -EFAULT; break; case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: if (put_user(0, (int *) arg)) return -EFAULT; break; case WDIOC_KEEPALIVE: riowd_pingtimer(); break; case WDIOC_SETOPTIONS: if (copy_from_user(&options, (void *) arg, sizeof(options))) return -EFAULT; if (options & WDIOS_DISABLECARD) riowd_stoptimer(); else if (options & WDIOS_ENABLECARD) riowd_starttimer(); else return -EINVAL; break; default: return -EINVAL; }; return 0; } static ssize_t riowd_write(struct file *file, const char *buf, size_t count, loff_t *ppos) { if (ppos != &file->f_pos) return -ESPIPE; if (count) { riowd_pingtimer(); return 1; } return 0; } static ssize_t riowd_read(struct file *file, char *buffer, size_t count, loff_t *ppos) { return -EINVAL; } static struct file_operations riowd_fops = { owner: THIS_MODULE, ioctl: riowd_ioctl, open: riowd_open, write: riowd_write, read: riowd_read, release: riowd_release, }; static struct miscdevice riowd_miscdev = { RIOWD_MINOR, RIOWD_NAME, &riowd_fops }; static int __init riowd_bbc_init(void) { struct linux_ebus *ebus = NULL; struct linux_ebus_device *edev = NULL; u8 val; for_each_ebus(ebus) { for_each_ebusdev(edev, ebus) { if (!strcmp(edev->prom_name, "bbc")) goto found_bbc; } } found_bbc: if (!edev) return -ENODEV; bbc_regs = ioremap(edev->resource[0].start, BBC_REGS_SIZE); if (!bbc_regs) return -ENODEV; /* Turn it off. */ val = readb(bbc_regs + BBC_WDACTION); val &= ~BBC_WDACTION_RST; writeb(val, bbc_regs + BBC_WDACTION); return 0; } static int __init riowd_init(void) { struct linux_ebus *ebus = NULL; struct linux_ebus_device *edev = NULL; for_each_ebus(ebus) { for_each_ebusdev(edev, ebus) { if (!strcmp(edev->prom_name, RIOWD_NAME)) goto ebus_done; } } ebus_done: if (!edev) goto fail; riowd_regs = ioremap(edev->resource[0].start, 2); if (riowd_regs == NULL) { printk(KERN_ERR "pmc: Cannot map registers.\n"); return -ENODEV; } if (riowd_bbc_init()) { printk(KERN_ERR "pmc: Failure initializing BBC config.\n"); goto fail; } if (misc_register(&riowd_miscdev)) { printk(KERN_ERR "pmc: Cannot register watchdog misc device.\n"); goto fail; } printk(KERN_INFO "pmc: Hardware watchdog [%i minutes], " "regs at %p\n", riowd_timeout, riowd_regs); return 0; fail: if (riowd_regs) { iounmap(riowd_regs); riowd_regs = NULL; } if (bbc_regs) { iounmap(bbc_regs); bbc_regs = NULL; } return -ENODEV; } static void __exit riowd_cleanup(void) { misc_deregister(&riowd_miscdev); iounmap(riowd_regs); riowd_regs = NULL; iounmap(bbc_regs); bbc_regs = NULL; } module_init(riowd_init); module_exit(riowd_cleanup);