[WATCHDOG] Add support for the built-int RDC R-321x SoC watchdog

This patch adds support for the built-in RDC R-321x SoC watchdog.

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

3 files changed, 296 insertions, 0 deletions

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index a8e80f2eb8ae..a1f47c7d7cd6 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -465,6 +465,16 @@ config PC87413_WDT
 
           Most people will say N.
 
+config RDC321X_WDT
+        tristate "RDC R-321x SoC watchdog"
+        depends on X86_RDC321X
+        help
+          This is the driver for the built in hardware watchdog
+          in the RDC R-321x SoC.
+
+          To compile this driver as a module, choose M here: the
+          module will be called rdc321x_wdt.
+
 config 60XX_WDT
         tristate "SBC-60XX Watchdog Timer"
         depends on X86
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 1b5c0118cfe6..a88be6fdadfc 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -75,6 +75,7 @@ obj-$(CONFIG_HP_WATCHDOG) += hpwdt.o
 obj-$(CONFIG_SC1200_WDT) += sc1200wdt.o
 obj-$(CONFIG_SCx200_WDT) += scx200_wdt.o
 obj-$(CONFIG_PC87413_WDT) += pc87413_wdt.o
+obj-$(CONFIG_RDC321X_WDT) += rdc321x_wdt.o
 obj-$(CONFIG_60XX_WDT) += sbc60xxwdt.o
 obj-$(CONFIG_SBC8360_WDT) += sbc8360.o
 obj-$(CONFIG_SBC7240_WDT) += sbc7240_wdt.o
diff --git a/drivers/watchdog/rdc321x_wdt.c b/drivers/watchdog/rdc321x_wdt.c
new file mode 100644
index 000000000000..9108efa73e7d
--- /dev/null
+++ b/drivers/watchdog/rdc321x_wdt.c
@@ -0,0 +1,285 @@
+/*
+ * RDC321x watchdog driver
+ *
+ * Copyright (C) 2007 Florian Fainelli <florian@openwrt.org>
+ *
+ * This driver is highly inspired from the cpu5_wdt driver
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/timer.h>
+#include <linux/completion.h>
+#include <linux/jiffies.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+#include <asm/mach-rdc321x/rdc321x_defs.h>
+
+#define RDC_WDT_MASK    0x80000000 /* Mask */
+#define RDC_WDT_EN      0x00800000 /* Enable bit */
+#define RDC_WDT_WTI     0x00200000 /* Generate CPU reset/NMI/WDT on timeout */
+#define RDC_WDT_RST     0x00100000 /* Reset bit */
+#define RDC_WDT_WIF     0x00040000 /* WDT IRQ Flag */
+#define RDC_WDT_IRT     0x00000100 /* IRQ Routing table */
+#define RDC_WDT_CNT     0x00000001 /* WDT count */
+
+#define RDC_CLS_TMR     0x80003844 /* Clear timer */
+
+#define RDC_WDT_INTERVAL        (HZ/10+1)
+
+static int ticks = 1000;
+
+/* some device data */
+
+static struct {
+        struct completion stop;
+        int running;
+        struct timer_list timer;
+        int queue;
+        int default_ticks;
+        unsigned long inuse;
+        spinlock_t lock;
+} rdc321x_wdt_device;
+
+/* generic helper functions */
+
+static void rdc321x_wdt_trigger(unsigned long unused)
+{
+        unsigned long flags;
+
+        if (rdc321x_wdt_device.running)
+                ticks--;
+
+        /* keep watchdog alive */
+        spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
+        outl(RDC_WDT_EN | inl(RDC3210_CFGREG_DATA),
+                RDC3210_CFGREG_DATA);
+        spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);
+
+        /* requeue?? */
+        if (rdc321x_wdt_device.queue && ticks)
+                mod_timer(&rdc321x_wdt_device.timer,
+                                jiffies + RDC_WDT_INTERVAL);
+        else {
+                /* ticks doesn't matter anyway */
+                complete(&rdc321x_wdt_device.stop);
+        }
+
+}
+
+static void rdc321x_wdt_reset(void)
+{
+        ticks = rdc321x_wdt_device.default_ticks;
+}
+
+static void rdc321x_wdt_start(void)
+{
+        unsigned long flags;
+
+        if (!rdc321x_wdt_device.queue) {
+                rdc321x_wdt_device.queue = 1;
+
+                /* Clear the timer */
+                spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
+                outl(RDC_CLS_TMR, RDC3210_CFGREG_ADDR);
+
+                /* Enable watchdog and set the timeout to 81.92 us */
+                outl(RDC_WDT_EN | RDC_WDT_CNT, RDC3210_CFGREG_DATA);
+                spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);
+
+                mod_timer(&rdc321x_wdt_device.timer,
+                                jiffies + RDC_WDT_INTERVAL);
+        }
+
+        /* if process dies, counter is not decremented */
+        rdc321x_wdt_device.running++;
+}
+
+static int rdc321x_wdt_stop(void)
+{
+        if (rdc321x_wdt_device.running)
+                rdc321x_wdt_device.running = 0;
+
+        ticks = rdc321x_wdt_device.default_ticks;
+
+        return -EIO;
+}
+
+/* filesystem operations */
+static int rdc321x_wdt_open(struct inode *inode, struct file *file)
+{
+        if (test_and_set_bit(0, &rdc321x_wdt_device.inuse))
+                return -EBUSY;
+
+        return nonseekable_open(inode, file);
+}
+
+static int rdc321x_wdt_release(struct inode *inode, struct file *file)
+{
+        clear_bit(0, &rdc321x_wdt_device.inuse);
+        return 0;
+}
+
+static int rdc321x_wdt_ioctl(struct inode *inode, struct file *file,
+                                unsigned int cmd, unsigned long arg)
+{
+        void __user *argp = (void __user *)arg;
+        unsigned int value;
+        static struct watchdog_info ident = {
+                .options = WDIOF_CARDRESET,
+                .identity = "RDC321x WDT",
+        };
+        unsigned long flags;
+
+        switch (cmd) {
+        case WDIOC_KEEPALIVE:
+                rdc321x_wdt_reset();
+                break;
+        case WDIOC_GETSTATUS:
+                /* Read the value from the DATA register */
+                spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
+                value = inl(RDC3210_CFGREG_DATA);
+                spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);
+                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:
+                        rdc321x_wdt_start();
+                        break;
+                case WDIOS_DISABLECARD:
+                        return rdc321x_wdt_stop();
+                default:
+                        return -EINVAL;
+                }
+                break;
+        default:
+                return -ENOTTY;
+        }
+        return 0;
+}
+
+static ssize_t rdc321x_wdt_write(struct file *file, const char __user *buf,
+                                size_t count, loff_t *ppos)
+{
+        if (!count)
+                return -EIO;
+
+        rdc321x_wdt_reset();
+
+        return count;
+}
+
+static const struct file_operations rdc321x_wdt_fops = {
+        .owner          = THIS_MODULE,
+        .llseek         = no_llseek,
+        .ioctl          = rdc321x_wdt_ioctl,
+        .open           = rdc321x_wdt_open,
+        .write          = rdc321x_wdt_write,
+        .release        = rdc321x_wdt_release,
+};
+
+static struct miscdevice rdc321x_wdt_misc = {
+        .minor  = WATCHDOG_MINOR,
+        .name   = "watchdog",
+        .fops   = &rdc321x_wdt_fops,
+};
+
+static int __devinit rdc321x_wdt_probe(struct platform_device *pdev)
+{
+        int err;
+
+        err = misc_register(&rdc321x_wdt_misc);
+        if (err < 0) {
+                printk(KERN_ERR PFX "watchdog misc_register failed\n");
+                return err;
+        }
+
+        spin_lock_init(&rdc321x_wdt_device.lock);
+
+        /* Reset the watchdog */
+        outl(RDC_WDT_RST, RDC3210_CFGREG_DATA);
+
+        init_completion(&rdc321x_wdt_device.stop);
+        rdc321x_wdt_device.queue = 0;
+
+        clear_bit(0, &rdc321x_wdt_device.inuse);
+
+        setup_timer(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0);
+
+        rdc321x_wdt_device.default_ticks = ticks;
+
+        printk(KERN_INFO PFX "watchdog init success\n");
+
+        return 0;
+}
+
+static int rdc321x_wdt_remove(struct platform_device *pdev)
+{
+        if (rdc321x_wdt_device.queue) {
+                rdc321x_wdt_device.queue = 0;
+                wait_for_completion(&rdc321x_wdt_device.stop);
+        }
+
+        misc_deregister(&rdc321x_wdt_misc);
+
+        return 0;
+}
+
+static struct platform_driver rdc321x_wdt_driver = {
+        .probe = rdc321x_wdt_probe,
+        .remove = rdc321x_wdt_remove,
+        .driver = {
+                .owner = THIS_MODULE,
+                .name = "rdc321x-wdt",
+        },
+};
+
+static int __init rdc321x_wdt_init(void)
+{
+        return platform_driver_register(&rdc321x_wdt_driver);
+}
+
+static void __exit rdc321x_wdt_exit(void)
+{
+        platform_driver_unregister(&rdc321x_wdt_driver);
+}
+
+module_init(rdc321x_wdt_init);
+module_exit(rdc321x_wdt_exit);
+
+MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
+MODULE_DESCRIPTION("RDC321x watchdog driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);