/* * 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. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/bitops.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/miscdevice.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/types.h> #include <linux/uaccess.h> #include <linux/watchdog.h> #include <linux/timer.h> #include <linux/jiffies.h> #include <linux/interrupt.h> #include <linux/ptrace.h> #include <linux/resource.h> #include <linux/platform_device.h> #include <bcm63xx_cpu.h> #include <bcm63xx_io.h> #include <bcm63xx_regs.h> #include <bcm63xx_timer.h> #define PFX KBUILD_MODNAME #define WDT_HZ 50000000 /* Fclk */ #define WDT_DEFAULT_TIME 30 /* seconds */ #define WDT_MAX_TIME 256 /* seconds */ static struct { void __iomem *regs; struct timer_list timer; unsigned long inuse; atomic_t ticks; } bcm63xx_wdt_device; static int expect_close; static int wdt_time = WDT_DEFAULT_TIME; 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) ")"); /* HW functions */ static void bcm63xx_wdt_hw_start(void) { bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG); 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_hw_stop(void) { bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG); bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG); } static void bcm63xx_wdt_isr(void *data) { struct pt_regs *regs = get_irq_regs(); die(PFX " fire", regs); } static void bcm63xx_timer_tick(unsigned long unused) { if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) { bcm63xx_wdt_hw_start(); mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ); } else pr_crit("watchdog will restart system\n"); } static void bcm63xx_wdt_pet(void) { atomic_set(&bcm63xx_wdt_device.ticks, wdt_time); } static void bcm63xx_wdt_start(void) { bcm63xx_wdt_pet(); bcm63xx_timer_tick(0); } static void bcm63xx_wdt_pause(void) { del_timer_sync(&bcm63xx_wdt_device.timer); bcm63xx_wdt_hw_stop(); } static int bcm63xx_wdt_settimeout(int new_time) { if ((new_time <= 0) || (new_time > WDT_MAX_TIME)) return -EINVAL; wdt_time = new_time; return 0; } static int bcm63xx_wdt_open(struct inode *inode, struct file *file) { if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse)) return -EBUSY; bcm63xx_wdt_start(); return nonseekable_open(inode, file); } static int bcm63xx_wdt_release(struct inode *inode, struct file *file) { if (expect_close == 42) bcm63xx_wdt_pause(); else { pr_crit("Unexpected close, not stopping watchdog!\n"); bcm63xx_wdt_start(); } clear_bit(0, &bcm63xx_wdt_device.inuse); expect_close = 0; 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 = 42; } } bcm63xx_wdt_pet(); } return len; } static struct watchdog_info bcm63xx_wdt_info = { .identity = PFX, .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, }; static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { void __user *argp = (void __user *)arg; int __user *p = argp; int new_value, retval = -EINVAL; switch (cmd) { case WDIOC_GETSUPPORT: return copy_to_user(argp, &bcm63xx_wdt_info, sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0; case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: return put_user(0, p); case WDIOC_SETOPTIONS: if (get_user(new_value, p)) return -EFAULT; if (new_value & WDIOS_DISABLECARD) { bcm63xx_wdt_pause(); retval = 0; } if (new_value & WDIOS_ENABLECARD) { bcm63xx_wdt_start(); retval = 0; } return retval; case WDIOC_KEEPALIVE: bcm63xx_wdt_pet(); return 0; case WDIOC_SETTIMEOUT: if (get_user(new_value, p)) return -EFAULT; if (bcm63xx_wdt_settimeout(new_value)) return -EINVAL; bcm63xx_wdt_pet(); case WDIOC_GETTIMEOUT: return put_user(wdt_time, p); default: return -ENOTTY; } } static const 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; setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0L); r = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!r) { dev_err(&pdev->dev, "failed to get resources\n"); return -ENODEV; } bcm63xx_wdt_device.regs = devm_ioremap_nocache(&pdev->dev, r->start, resource_size(r)); if (!bcm63xx_wdt_device.regs) { dev_err(&pdev->dev, "failed to remap I/O resources\n"); return -ENXIO; } ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL); if (ret < 0) { dev_err(&pdev->dev, "failed to register wdt timer isr\n"); return ret; } if (bcm63xx_wdt_settimeout(wdt_time)) { bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME); dev_info(&pdev->dev, ": wdt_time value must be 1 <= wdt_time <= 256, using %d\n", wdt_time); } ret = misc_register(&bcm63xx_wdt_miscdev); if (ret < 0) { dev_err(&pdev->dev, "failed to register watchdog device\n"); goto unregister_timer; } dev_info(&pdev->dev, " started, timer margin: %d sec\n", WDT_DEFAULT_TIME); return 0; unregister_timer: bcm63xx_timer_unregister(TIMER_WDT_ID); return ret; } static int bcm63xx_wdt_remove(struct platform_device *pdev) { if (!nowayout) bcm63xx_wdt_pause(); misc_deregister(&bcm63xx_wdt_miscdev); bcm63xx_timer_unregister(TIMER_WDT_ID); return 0; } static void bcm63xx_wdt_shutdown(struct platform_device *pdev) { bcm63xx_wdt_pause(); } static struct platform_driver bcm63xx_wdt_driver = { .probe = bcm63xx_wdt_probe, .remove = bcm63xx_wdt_remove, .shutdown = bcm63xx_wdt_shutdown, .driver = { .name = "bcm63xx-wdt", } }; module_platform_driver(bcm63xx_wdt_driver); 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("platform:bcm63xx-wdt");