[WATCHDOG] Add pnx833x_wdt

Add support for PNX833x watchdog timer.

Signed-off-by: Daniel Laird <daniel.j.laird@nxp.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

1 files changed, 282 insertions, 0 deletions

diff --git a/drivers/watchdog/pnx833x_wdt.c b/drivers/watchdog/pnx833x_wdt.c
new file mode 100644
index 000000000000..538ec2c05197
--- /dev/null
+++ b/drivers/watchdog/pnx833x_wdt.c
@@ -0,0 +1,282 @@
+/*
+ *  PNX833x Hardware Watchdog Driver
+ *  Copyright 2008 NXP Semiconductors
+ *  Daniel Laird <daniel.j.laird@nxp.com>
+ *  Andre McCurdy <andre.mccurdy@nxp.com>
+ *
+ *  Heavily based upon - IndyDog        0.3
+ *  A Hardware Watchdog Device for SGI IP22
+ *
+ * (c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>, 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.
+ *
+ * based on softdog.c by Alan Cox <alan@redhat.com>
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.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/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <asm/mach-pnx833x/pnx833x.h>
+
+#define PFX "pnx833x: "
+#define WATCHDOG_TIMEOUT 30             /* 30 sec Maximum timeout */
+#define WATCHDOG_COUNT_FREQUENCY 68000000U /* Watchdog counts at 68MHZ. */
+
+/** CONFIG block */
+#define PNX833X_CONFIG                      (0x07000U)
+#define PNX833X_CONFIG_CPU_WATCHDOG         (0x54)
+#define PNX833X_CONFIG_CPU_WATCHDOG_COMPARE (0x58)
+#define PNX833X_CONFIG_CPU_COUNTERS_CONTROL (0x1c)
+
+/** RESET block */
+#define PNX833X_RESET                       (0x08000U)
+#define PNX833X_RESET_CONFIG                (0x08)
+
+static int pnx833x_wdt_alive;
+
+/* Set default timeout in MHZ.*/
+static int pnx833x_wdt_timeout = (WATCHDOG_TIMEOUT * WATCHDOG_COUNT_FREQUENCY);
+module_param(pnx833x_wdt_timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in Mhz. (68Mhz clock), default="
+                        __MODULE_STRING(pnx833x_wdt_timeout) "(30 seconds).");
+
+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 int start_enabled = 1;
+module_param(start_enabled, int, 0);
+MODULE_PARM_DESC(start_enabled, "Watchdog is started on module insertion "
+                                "(default=" __MODULE_STRING(start_enabled) ")");
+
+static void pnx833x_wdt_start(void)
+{
+        /* Enable watchdog causing reset. */
+        PNX833X_REG(PNX833X_RESET + PNX833X_RESET_CONFIG) |= 0x1;
+        /* Set timeout.*/
+        PNX833X_REG(PNX833X_CONFIG +
+                PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout;
+        /* Enable watchdog. */
+        PNX833X_REG(PNX833X_CONFIG +
+                                PNX833X_CONFIG_CPU_COUNTERS_CONTROL) |= 0x1;
+
+        printk(KERN_INFO PFX "Started watchdog timer.\n");
+}
+
+static void pnx833x_wdt_stop(void)
+{
+        /* Disable watchdog causing reset. */
+        PNX833X_REG(PNX833X_RESET + PNX833X_CONFIG) &= 0xFFFFFFFE;
+        /* Disable watchdog.*/
+        PNX833X_REG(PNX833X_CONFIG +
+                        PNX833X_CONFIG_CPU_COUNTERS_CONTROL) &= 0xFFFFFFFE;
+
+        printk(KERN_INFO PFX "Stopped watchdog timer.\n");
+}
+
+static void pnx833x_wdt_ping(void)
+{
+        PNX833X_REG(PNX833X_CONFIG +
+                PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout;
+}
+
+/*
+ *      Allow only one person to hold it open
+ */
+static int pnx833x_wdt_open(struct inode *inode, struct file *file)
+{
+        if (test_and_set_bit(0, &pnx833x_wdt_alive))
+                return -EBUSY;
+
+        if (nowayout)
+                __module_get(THIS_MODULE);
+
+        /* Activate timer */
+        if (!start_enabled)
+                pnx833x_wdt_start();
+
+        pnx833x_wdt_ping();
+
+        printk(KERN_INFO "Started watchdog timer.\n");
+
+        return nonseekable_open(inode, file);
+}
+
+static int pnx833x_wdt_release(struct inode *inode, struct file *file)
+{
+        /* Shut off the timer.
+         * Lock it in if it's a module and we defined ...NOWAYOUT */
+        if (!nowayout)
+                pnx833x_wdt_stop(); /* Turn the WDT off */
+
+        clear_bit(0, &pnx833x_wdt_alive);
+        return 0;
+}
+
+static ssize_t pnx833x_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
+{
+        /* Refresh the timer. */
+        if (len)
+                pnx833x_wdt_ping();
+
+        return len;
+}
+
+static long pnx833x_wdt_ioctl(struct file *file, unsigned int cmd,
+                                                        unsigned long arg)
+{
+        int options, new_timeout = 0;
+        uint32_t timeout, timeout_left = 0;
+
+        static struct watchdog_info ident = {
+                .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
+                .firmware_version = 0,
+                .identity = "Hardware Watchdog for PNX833x",
+        };
+
+        switch (cmd) {
+        default:
+                return -ENOTTY;
+
+        case WDIOC_GETSUPPORT:
+                if (copy_to_user((struct watchdog_info *)arg,
+                                 &ident, sizeof(ident)))
+                        return -EFAULT;
+                return 0;
+
+        case WDIOC_GETSTATUS:
+        case WDIOC_GETBOOTSTATUS:
+                return put_user(0, (int *)arg);
+
+        case WDIOC_SETOPTIONS:
+                if (get_user(options, (int *)arg))
+                        return -EFAULT;
+
+                if (options & WDIOS_DISABLECARD)
+                        pnx833x_wdt_stop();
+
+                if (options & WDIOS_ENABLECARD)
+                        pnx833x_wdt_start();
+
+                return 0;
+
+        case WDIOC_KEEPALIVE:
+                pnx833x_wdt_ping();
+                return 0;
+
+        case WDIOC_SETTIMEOUT:
+        {
+                if (get_user(new_timeout, (int *)arg))
+                        return -EFAULT;
+
+                pnx833x_wdt_timeout = new_timeout;
+                PNX833X_REG(PNX833X_CONFIG +
+                        PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = new_timeout;
+                return put_user(new_timeout, (int *)arg);
+        }
+
+        case WDIOC_GETTIMEOUT:
+                timeout = PNX833X_REG(PNX833X_CONFIG +
+                                        PNX833X_CONFIG_CPU_WATCHDOG_COMPARE);
+                return put_user(timeout, (int *)arg);
+
+        case WDIOC_GETTIMELEFT:
+                timeout_left = PNX833X_REG(PNX833X_CONFIG +
+                                                PNX833X_CONFIG_CPU_WATCHDOG);
+                return put_user(timeout_left, (int *)arg);
+
+        }
+}
+
+static int pnx833x_wdt_notify_sys(struct notifier_block *this,
+                                        unsigned long code, void *unused)
+{
+        if (code == SYS_DOWN || code == SYS_HALT)
+                pnx833x_wdt_stop(); /* Turn the WDT off */
+
+        return NOTIFY_DONE;
+}
+
+static const struct file_operations pnx833x_wdt_fops = {
+        .owner          = THIS_MODULE,
+        .llseek         = no_llseek,
+        .write          = pnx833x_wdt_write,
+        .unlocked_ioctl = pnx833x_wdt_ioctl,
+        .open           = pnx833x_wdt_open,
+        .release        = pnx833x_wdt_release,
+};
+
+static struct miscdevice pnx833x_wdt_miscdev = {
+        .minor          = WATCHDOG_MINOR,
+        .name           = "watchdog",
+        .fops           = &pnx833x_wdt_fops,
+};
+
+static struct notifier_block pnx833x_wdt_notifier = {
+        .notifier_call = pnx833x_wdt_notify_sys,
+};
+
+static char banner[] __initdata =
+        KERN_INFO PFX "Hardware Watchdog Timer for PNX833x: Version 0.1\n";
+
+static int __init watchdog_init(void)
+{
+        int ret, cause;
+
+        /* Lets check the reason for the reset.*/
+        cause = PNX833X_REG(PNX833X_RESET);
+        /*If bit 31 is set then watchdog was cause of reset.*/
+        if (cause & 0x80000000) {
+                printk(KERN_INFO PFX "The system was previously reset due to "
+                        "the watchdog firing - please investigate...\n");
+        }
+
+        ret = register_reboot_notifier(&pnx833x_wdt_notifier);
+        if (ret) {
+                printk(KERN_ERR PFX
+                        "cannot register reboot notifier (err=%d)\n", ret);
+                return ret;
+        }
+
+        ret = misc_register(&pnx833x_wdt_miscdev);
+        if (ret) {
+                printk(KERN_ERR PFX
+                        "cannot register miscdev on minor=%d (err=%d)\n",
+                        WATCHDOG_MINOR, ret);
+                unregister_reboot_notifier(&pnx833x_wdt_notifier);
+                return ret;
+        }
+
+        printk(banner);
+        if (start_enabled)
+                pnx833x_wdt_start();
+
+        return 0;
+}
+
+static void __exit watchdog_exit(void)
+{
+        misc_deregister(&pnx833x_wdt_miscdev);
+        unregister_reboot_notifier(&pnx833x_wdt_notifier);
+}
+
+module_init(watchdog_init);
+module_exit(watchdog_exit);
+
+MODULE_AUTHOR("Daniel Laird/Andre McCurdy");
+MODULE_DESCRIPTION("Hardware Watchdog Device for PNX833x");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);