static ssize_t acq_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { /* See if we got the magic character 'V' and reload the timer */ if(count) { if (!nowayout) { size_t i; /* note: just in case someone wrote the magic character * five months ago... */ expect_close = 0; /* scan to see whether or not we got the magic character */ for (i = 0; i != count; i++) { char c; if (get_user(c, buf + i)) return -EFAULT; if (c == 'V') expect_close = 42; } } /* Well, anyhow someone wrote to us, we should return that favour */ acq_keepalive(); } return count; }
static ssize_t acq_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; } } acq_keepalive(); } return count; }
static int acq_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { int options, retval = -EINVAL; void __user *argp = (void __user *)arg; int __user *p = argp; static struct watchdog_info ident = { .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, .firmware_version = 1, .identity = "Acquire WDT", }; switch(cmd) { case WDIOC_GETSUPPORT: return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: return put_user(0, p); case WDIOC_KEEPALIVE: acq_keepalive(); return 0; case WDIOC_GETTIMEOUT: return put_user(WATCHDOG_HEARTBEAT, p); case WDIOC_SETOPTIONS: { if (get_user(options, p)) return -EFAULT; if (options & WDIOS_DISABLECARD) { acq_stop(); retval = 0; } if (options & WDIOS_ENABLECARD) { acq_keepalive(); retval = 0; } return retval; } default: return -ENOIOCTLCMD; } } static int acq_open(struct inode *inode, struct file *file) { if (test_and_set_bit(0, &acq_is_open)) return -EBUSY; if (nowayout) __module_get(THIS_MODULE); /* Activate */ acq_keepalive(); return nonseekable_open(inode, file); } static int acq_close(struct inode *inode, struct file *file) { if (expect_close == 42) { acq_stop(); } else { printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); acq_keepalive(); } clear_bit(0, &acq_is_open); expect_close = 0; return 0; } /* * Notifier for system down */ static int acq_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { if(code==SYS_DOWN || code==SYS_HALT) { /* Turn the WDT off */ acq_stop(); } return NOTIFY_DONE; } /* * Kernel Interfaces */ static struct file_operations acq_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = acq_write, .ioctl = acq_ioctl, .open = acq_open, .release = acq_close, }; static struct miscdevice acq_miscdev= { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &acq_fops, }; /* * The WDT card needs to learn about soft shutdowns in order to * turn the timebomb registers off. */ static struct notifier_block acq_notifier = { .notifier_call = acq_notify_sys, }; static int __init acq_init(void) { int ret; printk(KERN_INFO "WDT driver for Acquire single board computer initialising.\n"); if (wdt_stop != wdt_start) { if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) { printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", wdt_stop); ret = -EIO; goto out; } } if (!request_region(wdt_start, 1, WATCHDOG_NAME)) { printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", wdt_start); ret = -EIO; goto unreg_stop; } ret = register_reboot_notifier(&acq_notifier); if (ret != 0) { printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", ret); goto unreg_regions; } ret = misc_register(&acq_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. (nowayout=%d)\n", nowayout); return 0; unreg_reboot: unregister_reboot_notifier(&acq_notifier); unreg_regions: release_region(wdt_start, 1); unreg_stop: if (wdt_stop != wdt_start) release_region(wdt_stop, 1); out: return ret; } static void __exit acq_exit(void) { misc_deregister(&acq_miscdev); unregister_reboot_notifier(&acq_notifier); if(wdt_stop != wdt_start) release_region(wdt_stop,1); release_region(wdt_start,1); }
static int acq_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { int options, retval = -EINVAL; void __user *argp = (void __user *)arg; int __user *p = argp; static struct watchdog_info ident = { .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, .firmware_version = 1, .identity = WATCHDOG_NAME, }; switch(cmd) { case WDIOC_GETSUPPORT: return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: return put_user(0, p); case WDIOC_KEEPALIVE: acq_keepalive(); return 0; case WDIOC_GETTIMEOUT: return put_user(WATCHDOG_HEARTBEAT, p); case WDIOC_SETOPTIONS: { if (get_user(options, p)) return -EFAULT; if (options & WDIOS_DISABLECARD) { acq_stop(); retval = 0; } if (options & WDIOS_ENABLECARD) { acq_keepalive(); retval = 0; } return retval; } default: return -ENOTTY; } } static int acq_open(struct inode *inode, struct file *file) { if (test_and_set_bit(0, &acq_is_open)) return -EBUSY; if (nowayout) __module_get(THIS_MODULE); /* Activate */ acq_keepalive(); return nonseekable_open(inode, file); } static int acq_close(struct inode *inode, struct file *file) { if (expect_close == 42) { acq_stop(); } else { printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); acq_keepalive(); } clear_bit(0, &acq_is_open); expect_close = 0; return 0; } /* * Kernel Interfaces */ static const struct file_operations acq_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = acq_write, .ioctl = acq_ioctl, .open = acq_open, .release = acq_close, }; static struct miscdevice acq_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &acq_fops, }; /* * Init & exit routines */ static int __devinit acq_probe(struct platform_device *dev) { int ret; if (wdt_stop != wdt_start) { if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) { printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", wdt_stop); ret = -EIO; goto out; } } if (!request_region(wdt_start, 1, WATCHDOG_NAME)) { printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", wdt_start); ret = -EIO; goto unreg_stop; } ret = misc_register(&acq_miscdev); if (ret != 0) { printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", WATCHDOG_MINOR, ret); goto unreg_regions; } printk (KERN_INFO PFX "initialized. (nowayout=%d)\n", nowayout); return 0; unreg_regions: release_region(wdt_start, 1); unreg_stop: if (wdt_stop != wdt_start) release_region(wdt_stop, 1); out: return ret; } static int __devexit acq_remove(struct platform_device *dev) { misc_deregister(&acq_miscdev); release_region(wdt_start,1); if(wdt_stop != wdt_start) release_region(wdt_stop,1); return 0; }