[WATCHDOG] Add support for the IDT RC32434 watchdog

Add driver for the IDT RC32434 SoC built-in watchdog.

Signed-off-by: Florian Fainelli <florian.fainelli@telecomint.eu>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

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 000000000000..6756bcb009ed
--- /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);