// SPDX-License-Identifier: GPL-2.0-only /* * ALi M7101 PMU Computer Watchdog Timer driver * * Based on w83877f_wdt.c by Scott Jennings <[email protected]> * and the Cobalt kernel WDT timer driver by Tim Hockin * <[email protected]> * * (c)2002 Steve Hill <[email protected]> * * This WDT driver is different from most other Linux WDT * drivers in that the driver will ping the watchdog by itself, * because this particular WDT has a very short timeout (1.6 * seconds) and it would be insane to count on any userspace * daemon always getting scheduled within that time frame. * * Additions: * Aug 23, 2004 - Added use_gpio module parameter for use on revision a1d PMUs * found on very old cobalt hardware. * -- Mike Waychison <[email protected]> */ #define pr_fmt(fmt) … #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/types.h> #include <linux/timer.h> #include <linux/miscdevice.h> #include <linux/watchdog.h> #include <linux/ioport.h> #include <linux/notifier.h> #include <linux/reboot.h> #include <linux/init.h> #include <linux/fs.h> #include <linux/pci.h> #include <linux/io.h> #include <linux/uaccess.h> #define WDT_ENABLE … #define WDT_DISABLE … #define ALI_7101_WDT … #define ALI_7101_GPIO … #define ALI_7101_GPIO_O … #define ALI_WDT_ARM … /* * We're going to use a 1 second timeout. * If we reset the watchdog every ~250ms we should be safe. */ #define WDT_INTERVAL … /* * We must not require too good response from the userspace daemon. * Here we require the userspace daemon to send us a heartbeat * char to /dev/watchdog every 30 seconds. */ #define WATCHDOG_TIMEOUT … /* in seconds, will be multiplied by HZ to get seconds to wait for a ping */ static int timeout = …; module_param(timeout, int, 0); MODULE_PARM_DESC(…) …; static int use_gpio; /* Use the pic (for a1d revision alim7101) */ module_param(use_gpio, int, 0); MODULE_PARM_DESC(…) …; static void wdt_timer_ping(struct timer_list *); static DEFINE_TIMER(timer, wdt_timer_ping); static unsigned long next_heartbeat; static unsigned long wdt_is_open; static char wdt_expect_close; static struct pci_dev *alim7101_pmu; static bool nowayout = … WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0); MODULE_PARM_DESC(…) …; /* * Whack the dog */ static void wdt_timer_ping(struct timer_list *unused) { … } /* * Utility routines */ static void wdt_change(int writeval) { … } static void wdt_startup(void) { … } static void wdt_turnoff(void) { … } static void wdt_keepalive(void) { … } /* * /dev/watchdog handling */ static ssize_t fop_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { … } static int fop_open(struct inode *inode, struct file *file) { … } static int fop_close(struct inode *inode, struct file *file) { … } static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { … } static const struct file_operations wdt_fops = …; static struct miscdevice wdt_miscdev = …; static int wdt_restart_handle(struct notifier_block *this, unsigned long mode, void *cmd) { … } static struct notifier_block wdt_restart_handler = …; /* * Notifier for system down */ static int wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { … } /* * The WDT needs to learn about soft shutdowns in order to * turn the timebomb registers off. */ static struct notifier_block wdt_notifier = …; static void __exit alim7101_wdt_unload(void) { … } static int __init alim7101_wdt_init(void) { … } module_init(…) …; module_exit(alim7101_wdt_unload); static const struct pci_device_id alim7101_pci_tbl[] __used = …; MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl); MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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