1 files changed, 227 insertions, 0 deletions

diff --git a/drivers/watchdog/m54xx_wdt.c b/drivers/watchdog/m54xx_wdt.c
new file mode 100644
index 000000000000..4d43286074aa
--- /dev/null
+++ b/drivers/watchdog/m54xx_wdt.c
@@ -0,0 +1,227 @@
+/*
+ * drivers/watchdog/m54xx_wdt.c
+ *
+ * Watchdog driver for ColdFire MCF547x & MCF548x processors
+ * Copyright 2010 (c) Philippe De Muyter <phdm@macqel.be>
+ *
+ * Adapted from the IXP4xx watchdog driver, which carries these notices:
+ *
+ *  Author: Deepak Saxena <dsaxena@plexity.net>
+ *
+ *  Copyright 2004 (c) MontaVista, Software, Inc.
+ *  Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
+ *
+ * This file is licensed under  the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <linux/ioport.h>
+#include <linux/uaccess.h>
+
+#include <asm/coldfire.h>
+#include <asm/m54xxsim.h>
+#include <asm/m54xxgpt.h>
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+static unsigned int heartbeat = 30;     /* (secs) Default is 0.5 minute */
+static unsigned long wdt_status;
+
+#define WDT_IN_USE              0
+#define WDT_OK_TO_CLOSE         1
+
+static void wdt_enable(void)
+{
+        unsigned int gms0;
+
+        /* preserve GPIO usage, if any */
+        gms0 = __raw_readl(MCF_MBAR + MCF_GPT_GMS0);
+        if (gms0 & MCF_GPT_GMS_TMS_GPIO)
+                gms0 &= (MCF_GPT_GMS_TMS_GPIO | MCF_GPT_GMS_GPIO_MASK
+                                                        | MCF_GPT_GMS_OD);
+        else
+                gms0 = MCF_GPT_GMS_TMS_GPIO | MCF_GPT_GMS_OD;
+        __raw_writel(gms0, MCF_MBAR + MCF_GPT_GMS0);
+        __raw_writel(MCF_GPT_GCIR_PRE(heartbeat*(MCF_BUSCLK/0xffff)) |
+                        MCF_GPT_GCIR_CNT(0xffff), MCF_MBAR + MCF_GPT_GCIR0);
+        gms0 |= MCF_GPT_GMS_OCPW(0xA5) | MCF_GPT_GMS_WDEN | MCF_GPT_GMS_CE;
+        __raw_writel(gms0, MCF_MBAR + MCF_GPT_GMS0);
+}
+
+static void wdt_disable(void)
+{
+        unsigned int gms0;
+
+        /* disable watchdog */
+        gms0 = __raw_readl(MCF_MBAR + MCF_GPT_GMS0);
+        gms0 &= ~(MCF_GPT_GMS_WDEN | MCF_GPT_GMS_CE);
+        __raw_writel(gms0, MCF_MBAR + MCF_GPT_GMS0);
+}
+
+static void wdt_keepalive(void)
+{
+        unsigned int gms0;
+
+        gms0 = __raw_readl(MCF_MBAR + MCF_GPT_GMS0);
+        gms0 |= MCF_GPT_GMS_OCPW(0xA5);
+        __raw_writel(gms0, MCF_MBAR + MCF_GPT_GMS0);
+}
+
+static int m54xx_wdt_open(struct inode *inode, struct file *file)
+{
+        if (test_and_set_bit(WDT_IN_USE, &wdt_status))
+                return -EBUSY;
+
+        clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+        wdt_enable();
+        return nonseekable_open(inode, file);
+}
+
+static ssize_t m54xx_wdt_write(struct file *file, const char *data,
+                                                size_t len, loff_t *ppos)
+{
+        if (len) {
+                if (!nowayout) {
+                        size_t i;
+
+                        clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+
+                        for (i = 0; i != len; i++) {
+                                char c;
+
+                                if (get_user(c, data + i))
+                                        return -EFAULT;
+                                if (c == 'V')
+                                        set_bit(WDT_OK_TO_CLOSE, &wdt_status);
+                        }
+                }
+                wdt_keepalive();
+        }
+        return len;
+}
+
+static const struct watchdog_info ident = {
+        .options        = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
+                                WDIOF_KEEPALIVEPING,
+        .identity       = "Coldfire M54xx Watchdog",
+};
+
+static long m54xx_wdt_ioctl(struct file *file, unsigned int cmd,
+                                                         unsigned long arg)
+{
+        int ret = -ENOTTY;
+        int time;
+
+        switch (cmd) {
+        case WDIOC_GETSUPPORT:
+                ret = copy_to_user((struct watchdog_info *)arg, &ident,
+                                   sizeof(ident)) ? -EFAULT : 0;
+                break;
+
+        case WDIOC_GETSTATUS:
+                ret = put_user(0, (int *)arg);
+                break;
+
+        case WDIOC_GETBOOTSTATUS:
+                ret = put_user(0, (int *)arg);
+                break;
+
+        case WDIOC_KEEPALIVE:
+                wdt_keepalive();
+                ret = 0;
+                break;
+
+        case WDIOC_SETTIMEOUT:
+                ret = get_user(time, (int *)arg);
+                if (ret)
+                        break;
+
+                if (time <= 0 || time > 30) {
+                        ret = -EINVAL;
+                        break;
+                }
+
+                heartbeat = time;
+                wdt_enable();
+                /* Fall through */
+
+        case WDIOC_GETTIMEOUT:
+                ret = put_user(heartbeat, (int *)arg);
+                break;
+        }
+        return ret;
+}
+
+static int m54xx_wdt_release(struct inode *inode, struct file *file)
+{
+        if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
+                wdt_disable();
+        else {
+                printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "
+                                        "timer will not stop\n");
+                wdt_keepalive();
+        }
+        clear_bit(WDT_IN_USE, &wdt_status);
+        clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+
+        return 0;
+}
+
+
+static const struct file_operations m54xx_wdt_fops = {
+        .owner          = THIS_MODULE,
+        .llseek         = no_llseek,
+        .write          = m54xx_wdt_write,
+        .unlocked_ioctl = m54xx_wdt_ioctl,
+        .open           = m54xx_wdt_open,
+        .release        = m54xx_wdt_release,
+};
+
+static struct miscdevice m54xx_wdt_miscdev = {
+        .minor          = WATCHDOG_MINOR,
+        .name           = "watchdog",
+        .fops           = &m54xx_wdt_fops,
+};
+
+static int __init m54xx_wdt_init(void)
+{
+        if (!request_mem_region(MCF_MBAR + MCF_GPT_GCIR0, 4,
+                                                "Coldfire M54xx Watchdog")) {
+                printk(KERN_WARNING
+                                "Coldfire M54xx Watchdog : I/O region busy\n");
+                return -EBUSY;
+        }
+        printk(KERN_INFO "ColdFire watchdog driver is loaded.\n");
+
+        return misc_register(&m54xx_wdt_miscdev);
+}
+
+static void __exit m54xx_wdt_exit(void)
+{
+        misc_deregister(&m54xx_wdt_miscdev);
+        release_mem_region(MCF_MBAR + MCF_GPT_GCIR0, 4);
+}
+
+module_init(m54xx_wdt_init);
+module_exit(m54xx_wdt_exit);
+
+MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
+MODULE_DESCRIPTION("Coldfire M54xx Watchdog");
+
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 30s)");
+
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);