/* * Broadcom BCM63xx SoC watchdog driver * * Copyright (C) 2007, Miguel Gaio <miguel.gaio@efixo.com> * Copyright (C) 2008, Florian Fainelli <florian@openwrt.org> * * 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. */ #include <linux/module.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/fs.h> #include <linux/mm.h> #include <linux/miscdevice.h> #include <linux/watchdog.h> #include <linux/reboot.h> #include <linux/smp_lock.h> #include <linux/init.h> #include <linux/platform_device.h> #include <linux/uaccess.h> #include <linux/timer.h> #include <bcm63xx_cpu.h> #include <bcm63xx_io.h> #include <bcm63xx_regs.h> #define PFX KBUILD_MODNAME #define WDT_HZ 50000000 /* Fclk */ #define WDT_INTERVAL (40) /* in seconds */ static struct { void __iomem *regs; struct completion stop; int running; struct timer_list timer; int queue; int default_ticks; unsigned long inuse; } bcm63xx_wdt_device; static int ticks = 100 * WDT_HZ; static int expect_close; static int timeout; static int nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, int, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); static void bcm63xx_wdt_toggle(void) { bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG); bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG); } static void bcm63xx_wdt_start(void) { if (!bcm63xx_wdt_device.inuse) { bcm63xx_wdt_toggle(); mod_timer(&bcm63xx_wdt_device.timer, jiffies + WDT_INTERVAL); } bcm63xx_wdt_device.running++; } static void bcm63xx_wdt_stop(void) { if (bcm63xx_wdt_device.running) { bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG); bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG); bcm63xx_wdt_device.running = 0; } } static void bcm63xx_wdt_set(int new_timeout) { new_timeout *= WDT_HZ; bcm_writel(new_timeout, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG); } static void bcm63xx_wdt_reset(void) { ticks = bcm63xx_wdt_device.default_ticks; } static void bcm63xx_wdt_update(unsigned long unused) { if (bcm63xx_wdt_device.running) ticks--; bcm63xx_wdt_toggle(); if (bcm63xx_wdt_device.queue && ticks) mod_timer(&bcm63xx_wdt_device.timer, jiffies + WDT_INTERVAL); else complete(&bcm63xx_wdt_device.stop); } static int bcm63xx_wdt_open(struct inode *inode, struct file *file) { if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse)) return -EBUSY; if (nowayout) __module_get(THIS_MODULE); return nonseekable_open(inode, file); } static int bcm63xx_wdt_release(struct inode *inode, struct file *file) { if (expect_close && nowayout == 0) { bcm63xx_wdt_stop(); printk(KERN_INFO PFX ": disabling watchdog timer\n"); module_put(THIS_MODULE); } else printk(KERN_CRIT PFX ": device closed unexpectedly. WDT will not stop !\n"); clear_bit(0, &bcm63xx_wdt_device.inuse); return 0; } static ssize_t bcm63xx_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) { if (len) { if (!nowayout) { size_t i; /* In case it was set long ago */ expect_close = 0; for (i = 0; i != len; i++) { char c; if (get_user(c, data + i)) return -EFAULT; if (c == 'V') expect_close = 1; } } bcm63xx_wdt_update(0); return len; } return 0; } static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { void __user *argp = (void __user *)arg; int new_timeout; unsigned int value; static struct watchdog_info ident = { .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, .identity = "BCM63xx Watchdog", }; switch (cmd) { case WDIOC_KEEPALIVE: bcm63xx_wdt_reset(); break; case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: value = bcm_readl(bcm63xx_wdt_device.regs + WDT_DEFVAL_REG); if (copy_to_user(argp, &value, sizeof(int))) return -EFAULT; break; case WDIOC_GETSUPPORT: if (copy_to_user(argp, &ident, sizeof(ident))) return -EFAULT; break; case WDIOC_SETOPTIONS: if (copy_from_user(&value, argp, sizeof(int))) return -EFAULT; switch (value) { case WDIOS_ENABLECARD: bcm63xx_wdt_start(); break; case WDIOS_DISABLECARD: bcm63xx_wdt_stop(); default: return -EINVAL; } break; case WDIOC_SETTIMEOUT: if (copy_from_user(&new_timeout, argp, sizeof(int))) return -EFAULT; if (new_timeout < 5) return -EINVAL; if (new_timeout > 40) return -EINVAL; bcm63xx_wdt_set(new_timeout); bcm63xx_wdt_toggle(); case WDIOC_GETTIMEOUT: return copy_to_user(argp, &timeout, sizeof(int)); default: return -ENOTTY; } return 0; } static struct file_operations bcm63xx_wdt_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = bcm63xx_wdt_write, .unlocked_ioctl = bcm63xx_wdt_ioctl, .open = bcm63xx_wdt_open, .release = bcm63xx_wdt_release, }; static struct miscdevice bcm63xx_wdt_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &bcm63xx_wdt_fops, }; static int bcm63xx_wdt_probe(struct platform_device *pdev) { int ret; struct resource *r; r = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!r) { printk(KERN_ERR PFX "failed to retrieve resources\n"); return -ENODEV; } bcm63xx_wdt_device.regs = ioremap_nocache(r->start, r->end - r->start); if (!bcm63xx_wdt_device.regs) { printk(KERN_ERR PFX "failed to remap I/O resources\n"); return -ENXIO; } ret = misc_register(&bcm63xx_wdt_miscdev); if (ret < 0) { printk(KERN_ERR PFX "failed to register watchdog device\n"); goto unmap; } init_completion(&bcm63xx_wdt_device.stop); bcm63xx_wdt_device.queue = 0; clear_bit(0, &bcm63xx_wdt_device.inuse); setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_wdt_update, 0L); bcm63xx_wdt_device.default_ticks = ticks; bcm63xx_wdt_set(ticks); bcm63xx_wdt_start(); printk(KERN_INFO PFX " started, timer margin: %d sec\n", WDT_INTERVAL); return 0; unmap: iounmap(bcm63xx_wdt_device.regs); return ret; } static int bcm63xx_wdt_remove(struct platform_device *pdev) { if (bcm63xx_wdt_device.queue) { bcm63xx_wdt_device.queue = 0; wait_for_completion(&bcm63xx_wdt_device.stop); } misc_deregister(&bcm63xx_wdt_miscdev); iounmap(bcm63xx_wdt_device.regs); return 0; } static struct platform_driver bcm63xx_wdt = { .probe = bcm63xx_wdt_probe, .remove = bcm63xx_wdt_remove, .driver = { .name = "bcm63xx-wdt", } }; static int __init bcm63xx_wdt_init(void) { return platform_driver_register(&bcm63xx_wdt); } static void __exit bcm63xx_wdt_exit(void) { platform_driver_unregister(&bcm63xx_wdt); } module_init(bcm63xx_wdt_init); module_exit(bcm63xx_wdt_exit); MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>"); MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>"); MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog"); MODULE_LICENSE("GPL"); MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); MODULE_ALIAS("platform:bcm63xx-wdt");