--- /dev/null
+/*
+ * 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);
projects / linux-2.6 / commitdiff