/* * PNX833x Hardware Watchdog Driver * Copyright 2008 NXP Semiconductors * Daniel Laird * Andre McCurdy * * Heavily based upon - IndyDog 0.3 * A Hardware Watchdog Device for SGI IP22 * * (c) Copyright 2002 Guido Guenther , All Rights Reserved. * * 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. * * based on softdog.c by Alan Cox */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #define WATCHDOG_TIMEOUT 30 /* 30 sec Maximum timeout */ #define WATCHDOG_COUNT_FREQUENCY 68000000U /* Watchdog counts at 68MHZ. */ #define PNX_WATCHDOG_TIMEOUT (WATCHDOG_TIMEOUT * WATCHDOG_COUNT_FREQUENCY) #define PNX_TIMEOUT_VALUE 2040000000U /** CONFIG block */ #define PNX833X_CONFIG (0x07000U) #define PNX833X_CONFIG_CPU_WATCHDOG (0x54) #define PNX833X_CONFIG_CPU_WATCHDOG_COMPARE (0x58) #define PNX833X_CONFIG_CPU_COUNTERS_CONTROL (0x1c) /** RESET block */ #define PNX833X_RESET (0x08000U) #define PNX833X_RESET_CONFIG (0x08) static int pnx833x_wdt_alive; /* Set default timeout in MHZ.*/ static int pnx833x_wdt_timeout = PNX_WATCHDOG_TIMEOUT; module_param(pnx833x_wdt_timeout, int, 0); MODULE_PARM_DESC(timeout, "Watchdog timeout in Mhz. (68Mhz clock), default=" __MODULE_STRING(PNX_TIMEOUT_VALUE) "(30 seconds)."); static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); #define START_DEFAULT 1 static int start_enabled = START_DEFAULT; module_param(start_enabled, int, 0); MODULE_PARM_DESC(start_enabled, "Watchdog is started on module insertion " "(default=" __MODULE_STRING(START_DEFAULT) ")"); static void pnx833x_wdt_start(void) { /* Enable watchdog causing reset. */ PNX833X_REG(PNX833X_RESET + PNX833X_RESET_CONFIG) |= 0x1; /* Set timeout.*/ PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout; /* Enable watchdog. */ PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_COUNTERS_CONTROL) |= 0x1; pr_info("Started watchdog timer\n"); } static void pnx833x_wdt_stop(void) { /* Disable watchdog causing reset. */ PNX833X_REG(PNX833X_RESET + PNX833X_CONFIG) &= 0xFFFFFFFE; /* Disable watchdog.*/ PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_COUNTERS_CONTROL) &= 0xFFFFFFFE; pr_info("Stopped watchdog timer\n"); } static void pnx833x_wdt_ping(void) { PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout; } /* * Allow only one person to hold it open */ static int pnx833x_wdt_open(struct inode *inode, struct file *file) { if (test_and_set_bit(0, &pnx833x_wdt_alive)) return -EBUSY; if (nowayout) __module_get(THIS_MODULE); /* Activate timer */ if (!start_enabled) pnx833x_wdt_start(); pnx833x_wdt_ping(); pr_info("Started watchdog timer\n"); return nonseekable_open(inode, file); } static int pnx833x_wdt_release(struct inode *inode, struct file *file) { /* Shut off the timer. * Lock it in if it's a module and we defined ...NOWAYOUT */ if (!nowayout) pnx833x_wdt_stop(); /* Turn the WDT off */ clear_bit(0, &pnx833x_wdt_alive); return 0; } static ssize_t pnx833x_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) { /* Refresh the timer. */ if (len) pnx833x_wdt_ping(); return len; } static long pnx833x_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { int options, new_timeout = 0; uint32_t timeout, timeout_left = 0; static const struct watchdog_info ident = { .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, .firmware_version = 0, .identity = "Hardware Watchdog for PNX833x", }; switch (cmd) { default: return -ENOTTY; case WDIOC_GETSUPPORT: if (copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident))) return -EFAULT; return 0; case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: return put_user(0, (int *)arg); case WDIOC_SETOPTIONS: if (get_user(options, (int *)arg)) return -EFAULT; if (options & WDIOS_DISABLECARD) pnx833x_wdt_stop(); if (options & WDIOS_ENABLECARD) pnx833x_wdt_start(); return 0; case WDIOC_KEEPALIVE: pnx833x_wdt_ping(); return 0; case WDIOC_SETTIMEOUT: { if (get_user(new_timeout, (int *)arg)) return -EFAULT; pnx833x_wdt_timeout = new_timeout; PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = new_timeout; return put_user(new_timeout, (int *)arg); } case WDIOC_GETTIMEOUT: timeout = PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_WATCHDOG_COMPARE); return put_user(timeout, (int *)arg); case WDIOC_GETTIMELEFT: timeout_left = PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_WATCHDOG); return put_user(timeout_left, (int *)arg); } } static int pnx833x_wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { if (code == SYS_DOWN || code == SYS_HALT) pnx833x_wdt_stop(); /* Turn the WDT off */ return NOTIFY_DONE; } static const struct file_operations pnx833x_wdt_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = pnx833x_wdt_write, .unlocked_ioctl = pnx833x_wdt_ioctl, .open = pnx833x_wdt_open, .release = pnx833x_wdt_release, }; static struct miscdevice pnx833x_wdt_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &pnx833x_wdt_fops, }; static struct notifier_block pnx833x_wdt_notifier = { .notifier_call = pnx833x_wdt_notify_sys, }; static int __init watchdog_init(void) { int ret, cause; /* Lets check the reason for the reset.*/ cause = PNX833X_REG(PNX833X_RESET); /*If bit 31 is set then watchdog was cause of reset.*/ if (cause & 0x80000000) { pr_info("The system was previously reset due to the watchdog firing - please investigate...\n"); } ret = register_reboot_notifier(&pnx833x_wdt_notifier); if (ret) { pr_err("cannot register reboot notifier (err=%d)\n", ret); return ret; } ret = misc_register(&pnx833x_wdt_miscdev); if (ret) { pr_err("cannot register miscdev on minor=%d (err=%d)\n", WATCHDOG_MINOR, ret); unregister_reboot_notifier(&pnx833x_wdt_notifier); return ret; } pr_info("Hardware Watchdog Timer for PNX833x: Version 0.1\n"); if (start_enabled) pnx833x_wdt_start(); return 0; } static void __exit watchdog_exit(void) { misc_deregister(&pnx833x_wdt_miscdev); unregister_reboot_notifier(&pnx833x_wdt_notifier); } module_init(watchdog_init); module_exit(watchdog_exit); MODULE_AUTHOR("Daniel Laird/Andre McCurdy"); MODULE_DESCRIPTION("Hardware Watchdog Device for PNX833x"); MODULE_LICENSE("GPL");