diff options
Diffstat (limited to 'drivers/watchdog/rc32434_wdt.c')
-rw-r--r-- | drivers/watchdog/rc32434_wdt.c | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/drivers/watchdog/rc32434_wdt.c b/drivers/watchdog/rc32434_wdt.c new file mode 100644 index 00000000000..6756bcb009e --- /dev/null +++ b/drivers/watchdog/rc32434_wdt.c @@ -0,0 +1,344 @@ +/* + * IDT Interprise 79RC32434 watchdog driver + * + * Copyright (C) 2006, Ondrej Zajicek <santiago@crfreenet.org> + * Copyright (C) 2008, Florian Fainelli <florian@openwrt.org> + * + * based on + * SoftDog 0.05: A Software Watchdog Device + * + * (c) Copyright 1996 Alan Cox <alan@redhat.com>, 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. + * + */ + +#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 <asm/bootinfo.h> +#include <asm/time.h> +#include <asm/mach-rc32434/integ.h> + +#define MAX_TIMEOUT 20 +#define RC32434_WDT_INTERVAL (15 * HZ) + +#define VERSION "0.2" + +static struct { + struct completion stop; + int running; + struct timer_list timer; + int queue; + int default_ticks; + unsigned long inuse; +} rc32434_wdt_device; + +static struct integ __iomem *wdt_reg; +static int ticks = 100 * 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 rc32434_wdt_start(void) +{ + u32 val; + + if (!rc32434_wdt_device.inuse) { + writel(0, &wdt_reg->wtcount); + + val = RC32434_ERR_WRE; + writel(readl(&wdt_reg->errcs) | val, &wdt_reg->errcs); + + val = RC32434_WTC_EN; + writel(readl(&wdt_reg->wtc) | val, &wdt_reg->wtc); + } + rc32434_wdt_device.running++; +} + +static void rc32434_wdt_stop(void) +{ + u32 val; + + if (rc32434_wdt_device.running) { + + val = ~RC32434_WTC_EN; + writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc); + + val = ~RC32434_ERR_WRE; + writel(readl(&wdt_reg->errcs) & val, &wdt_reg->errcs); + + rc32434_wdt_device.running = 0; + } +} + +static void rc32434_wdt_set(int new_timeout) +{ + u32 cmp = new_timeout * HZ; + u32 state, val; + + timeout = new_timeout; + /* + * store and disable WTC + */ + state = (u32)(readl(&wdt_reg->wtc) & RC32434_WTC_EN); + val = ~RC32434_WTC_EN; + writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc); + + writel(0, &wdt_reg->wtcount); + writel(cmp, &wdt_reg->wtcompare); + + /* + * restore WTC + */ + + writel(readl(&wdt_reg->wtc) | state, &wdt_reg); +} + +static void rc32434_wdt_reset(void) +{ + ticks = rc32434_wdt_device.default_ticks; +} + +static void rc32434_wdt_update(unsigned long unused) +{ + if (rc32434_wdt_device.running) + ticks--; + + writel(0, &wdt_reg->wtcount); + + if (rc32434_wdt_device.queue && ticks) + mod_timer(&rc32434_wdt_device.timer, + jiffies + RC32434_WDT_INTERVAL); + else + complete(&rc32434_wdt_device.stop); +} + +static int rc32434_wdt_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(0, &rc32434_wdt_device.inuse)) + return -EBUSY; + + if (nowayout) + __module_get(THIS_MODULE); + + return nonseekable_open(inode, file); +} + +static int rc32434_wdt_release(struct inode *inode, struct file *file) +{ + if (expect_close && nowayout == 0) { + rc32434_wdt_stop(); + printk(KERN_INFO KBUILD_MODNAME ": disabling watchdog timer\n"); + module_put(THIS_MODULE); + } else + printk(KERN_CRIT KBUILD_MODNAME + ": device closed unexpectedly. WDT will not stop !\n"); + + clear_bit(0, &rc32434_wdt_device.inuse); + return 0; +} + +static ssize_t rc32434_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; + } + } + rc32434_wdt_update(0); + return len; + } + return 0; +} + +static int rc32434_wdt_ioctl(struct inode *inode, 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 = "RC32434_WDT Watchdog", + }; + switch (cmd) { + case WDIOC_KEEPALIVE: + rc32434_wdt_reset(); + break; + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + value = readl(&wdt_reg->wtcount); + 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: + rc32434_wdt_start(); + break; + case WDIOS_DISABLECARD: + rc32434_wdt_stop(); + default: + return -EINVAL; + } + break; + case WDIOC_SETTIMEOUT: + if (copy_from_user(&new_timeout, argp, sizeof(int))) + return -EFAULT; + if (new_timeout < 1) + return -EINVAL; + if (new_timeout > MAX_TIMEOUT) + return -EINVAL; + rc32434_wdt_set(new_timeout); + case WDIOC_GETTIMEOUT: + return copy_to_user(argp, &timeout, sizeof(int)); + default: + return -ENOTTY; + } + + return 0; +} + +static struct file_operations rc32434_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = rc32434_wdt_write, + .ioctl = rc32434_wdt_ioctl, + .open = rc32434_wdt_open, + .release = rc32434_wdt_release, +}; + +static struct miscdevice rc32434_wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &rc32434_wdt_fops, +}; + +static char banner[] = KERN_INFO KBUILD_MODNAME + ": Watchdog Timer version " VERSION ", timer margin: %d sec\n"; + +static int rc32434_wdt_probe(struct platform_device *pdev) +{ + int ret; + struct resource *r; + + r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rb500_wdt_res"); + if (!r) { + printk(KERN_ERR KBUILD_MODNAME + "failed to retrieve resources\n"); + return -ENODEV; + } + + wdt_reg = ioremap_nocache(r->start, r->end - r->start); + if (!wdt_reg) { + printk(KERN_ERR KBUILD_MODNAME + "failed to remap I/O resources\n"); + return -ENXIO; + } + + ret = misc_register(&rc32434_wdt_miscdev); + + if (ret < 0) { + printk(KERN_ERR KBUILD_MODNAME + "failed to register watchdog device\n"); + goto unmap; + } + + init_completion(&rc32434_wdt_device.stop); + rc32434_wdt_device.queue = 0; + + clear_bit(0, &rc32434_wdt_device.inuse); + + setup_timer(&rc32434_wdt_device.timer, rc32434_wdt_update, 0L); + + rc32434_wdt_device.default_ticks = ticks; + + rc32434_wdt_start(); + + printk(banner, timeout); + + return 0; + +unmap: + iounmap(wdt_reg); + return ret; +} + +static int rc32434_wdt_remove(struct platform_device *pdev) +{ + if (rc32434_wdt_device.queue) { + rc32434_wdt_device.queue = 0; + wait_for_completion(&rc32434_wdt_device.stop); + } + misc_deregister(&rc32434_wdt_miscdev); + + iounmap(wdt_reg); + + return 0; +} + +static struct platform_driver rc32434_wdt = { + .probe = rc32434_wdt_probe, + .remove = rc32434_wdt_remove, + .driver = { + .name = "rc32434_wdt", + } +}; + +static int __init rc32434_wdt_init(void) +{ + return platform_driver_register(&rc32434_wdt); +} + +static void __exit rc32434_wdt_exit(void) +{ + platform_driver_unregister(&rc32434_wdt); +} + +module_init(rc32434_wdt_init); +module_exit(rc32434_wdt_exit); + +MODULE_AUTHOR("Ondrej Zajicek <santiago@crfreenet.org>," + "Florian Fainelli <florian@openwrt.org>"); +MODULE_DESCRIPTION("Driver for the IDT RC32434 SoC watchdog"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |