1 files changed, 325 insertions, 0 deletions
diff --git a/drivers/watchdog/ks8695_wdt.c b/drivers/watchdog/ks8695_wdt.c
new file mode 100644
index 000000000..b7ea39b45
--- /dev/null
+++ b/drivers/watchdog/ks8695_wdt.c
@@ -0,0 +1,325 @@
+/*
+ * Watchdog driver for Kendin/Micrel KS8695.
+ *
+ * (C) 2007 Andrew Victor
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/bitops.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <mach/hardware.h>
+
+#define KS8695_TMR_OFFSET	(0xF0000 + 0xE400)
+#define KS8695_TMR_VA		(KS8695_IO_VA + KS8695_TMR_OFFSET)
+
+/*
+ * Timer registers
+ */
+#define KS8695_TMCON		(0x00)		/* Timer Control Register */
+#define KS8695_T0TC		(0x08)		/* Timer 0 Timeout Count Register */
+#define TMCON_T0EN		(1 << 0)	/* Timer 0 Enable */
+
+/* Timer0 Timeout Counter Register */
+#define T0TC_WATCHDOG		(0xff)		/* Enable watchdog mode */
+
+#define WDT_DEFAULT_TIME	5	/* seconds */
+#define WDT_MAX_TIME		171	/* seconds */
+
+static int wdt_time = WDT_DEFAULT_TIME;
+static bool nowayout = WATCHDOG_NOWAYOUT;
+
+module_param(wdt_time, int, 0);
+MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="
+					__MODULE_STRING(WDT_DEFAULT_TIME) ")");
+
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+#endif
+
+
+static unsigned long ks8695wdt_busy;
+static DEFINE_SPINLOCK(ks8695_lock);
+
+/* ......................................................................... */
+
+/*
+ * Disable the watchdog.
+ */
+static inline void ks8695_wdt_stop(void)
+{
+	unsigned long tmcon;
+
+	spin_lock(&ks8695_lock);
+	/* disable timer0 */
+	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
+	__raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
+	spin_unlock(&ks8695_lock);
+}
+
+/*
+ * Enable and reset the watchdog.
+ */
+static inline void ks8695_wdt_start(void)
+{
+	unsigned long tmcon;
+	unsigned long tval = wdt_time * KS8695_CLOCK_RATE;
+
+	spin_lock(&ks8695_lock);
+	/* disable timer0 */
+	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
+	__raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
+
+	/* program timer0 */
+	__raw_writel(tval | T0TC_WATCHDOG, KS8695_TMR_VA + KS8695_T0TC);
+
+	/* re-enable timer0 */
+	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
+	__raw_writel(tmcon | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
+	spin_unlock(&ks8695_lock);
+}
+
+/*
+ * Reload the watchdog timer.  (ie, pat the watchdog)
+ */
+static inline void ks8695_wdt_reload(void)
+{
+	unsigned long tmcon;
+
+	spin_lock(&ks8695_lock);
+	/* disable, then re-enable timer0 */
+	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
+	__raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
+	__raw_writel(tmcon | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
+	spin_unlock(&ks8695_lock);
+}
+
+/*
+ * Change the watchdog time interval.
+ */
+static int ks8695_wdt_settimeout(int new_time)
+{
+	/*
+	 * All counting occurs at KS8695_CLOCK_RATE / 128 = 0.256 Hz
+	 *
+	 * Since WDV is a 16-bit counter, the maximum period is
+	 * 65536 / 0.256 = 256 seconds.
+	 */
+	if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
+		return -EINVAL;
+
+	/* Set new watchdog time. It will be used when
+	   ks8695_wdt_start() is called. */
+	wdt_time = new_time;
+	return 0;
+}
+
+/* ......................................................................... */
+
+/*
+ * Watchdog device is opened, and watchdog starts running.
+ */
+static int ks8695_wdt_open(struct inode *inode, struct file *file)
+{
+	if (test_and_set_bit(0, &ks8695wdt_busy))
+		return -EBUSY;
+
+	ks8695_wdt_start();
+	return nonseekable_open(inode, file);
+}
+
+/*
+ * Close the watchdog device.
+ * If CONFIG_WATCHDOG_NOWAYOUT is NOT defined then the watchdog is also
+ *  disabled.
+ */
+static int ks8695_wdt_close(struct inode *inode, struct file *file)
+{
+	/* Disable the watchdog when file is closed */
+	if (!nowayout)
+		ks8695_wdt_stop();
+	clear_bit(0, &ks8695wdt_busy);
+	return 0;
+}
+
+static const struct watchdog_info ks8695_wdt_info = {
+	.identity	= "ks8695 watchdog",
+	.options	= WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+};
+
+/*
+ * Handle commands from user-space.
+ */
+static long ks8695_wdt_ioctl(struct file *file, unsigned int cmd,
+							unsigned long arg)
+{
+	void __user *argp = (void __user *)arg;
+	int __user *p = argp;
+	int new_value;
+
+	switch (cmd) {
+	case WDIOC_GETSUPPORT:
+		return copy_to_user(argp, &ks8695_wdt_info,
+					sizeof(ks8695_wdt_info)) ? -EFAULT : 0;
+	case WDIOC_GETSTATUS:
+	case WDIOC_GETBOOTSTATUS:
+		return put_user(0, p);
+	case WDIOC_SETOPTIONS:
+		if (get_user(new_value, p))
+			return -EFAULT;
+		if (new_value & WDIOS_DISABLECARD)
+			ks8695_wdt_stop();
+		if (new_value & WDIOS_ENABLECARD)
+			ks8695_wdt_start();
+		return 0;
+	case WDIOC_KEEPALIVE:
+		ks8695_wdt_reload();	/* pat the watchdog */
+		return 0;
+	case WDIOC_SETTIMEOUT:
+		if (get_user(new_value, p))
+			return -EFAULT;
+		if (ks8695_wdt_settimeout(new_value))
+			return -EINVAL;
+		/* Enable new time value */
+		ks8695_wdt_start();
+		/* Return current value */
+		return put_user(wdt_time, p);
+	case WDIOC_GETTIMEOUT:
+		return put_user(wdt_time, p);
+	default:
+		return -ENOTTY;
+	}
+}
+
+/*
+ * Pat the watchdog whenever device is written to.
+ */
+static ssize_t ks8695_wdt_write(struct file *file, const char *data,
+						size_t len, loff_t *ppos)
+{
+	ks8695_wdt_reload();		/* pat the watchdog */
+	return len;
+}
+
+/* ......................................................................... */
+
+static const struct file_operations ks8695wdt_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.unlocked_ioctl	= ks8695_wdt_ioctl,
+	.open		= ks8695_wdt_open,
+	.release	= ks8695_wdt_close,
+	.write		= ks8695_wdt_write,
+};
+
+static struct miscdevice ks8695wdt_miscdev = {
+	.minor		= WATCHDOG_MINOR,
+	.name		= "watchdog",
+	.fops		= &ks8695wdt_fops,
+};
+
+static int ks8695wdt_probe(struct platform_device *pdev)
+{
+	int res;
+
+	if (ks8695wdt_miscdev.parent)
+		return -EBUSY;
+	ks8695wdt_miscdev.parent = &pdev->dev;
+
+	res = misc_register(&ks8695wdt_miscdev);
+	if (res)
+		return res;
+
+	pr_info("KS8695 Watchdog Timer enabled (%d seconds%s)\n",
+		wdt_time, nowayout ? ", nowayout" : "");
+	return 0;
+}
+
+static int ks8695wdt_remove(struct platform_device *pdev)
+{
+	int res;
+
+	res = misc_deregister(&ks8695wdt_miscdev);
+	if (!res)
+		ks8695wdt_miscdev.parent = NULL;
+
+	return res;
+}
+
+static void ks8695wdt_shutdown(struct platform_device *pdev)
+{
+	ks8695_wdt_stop();
+}
+
+#ifdef CONFIG_PM
+
+static int ks8695wdt_suspend(struct platform_device *pdev, pm_message_t message)
+{
+	ks8695_wdt_stop();
+	return 0;
+}
+
+static int ks8695wdt_resume(struct platform_device *pdev)
+{
+	if (ks8695wdt_busy)
+		ks8695_wdt_start();
+	return 0;
+}
+
+#else
+#define ks8695wdt_suspend NULL
+#define ks8695wdt_resume	NULL
+#endif
+
+static struct platform_driver ks8695wdt_driver = {
+	.probe		= ks8695wdt_probe,
+	.remove		= ks8695wdt_remove,
+	.shutdown	= ks8695wdt_shutdown,
+	.suspend	= ks8695wdt_suspend,
+	.resume		= ks8695wdt_resume,
+	.driver		= {
+		.name	= "ks8695_wdt",
+	},
+};
+
+static int __init ks8695_wdt_init(void)
+{
+	/* Check that the heartbeat value is within range;
+	   if not reset to the default */
+	if (ks8695_wdt_settimeout(wdt_time)) {
+		ks8695_wdt_settimeout(WDT_DEFAULT_TIME);
+		pr_info("ks8695_wdt: wdt_time value must be 1 <= wdt_time <= %i"
+					", using %d\n", wdt_time, WDT_MAX_TIME);
+	}
+	return platform_driver_register(&ks8695wdt_driver);
+}
+
+static void __exit ks8695_wdt_exit(void)
+{
+	platform_driver_unregister(&ks8695wdt_driver);
+}
+
+module_init(ks8695_wdt_init);
+module_exit(ks8695_wdt_exit);
+
+MODULE_AUTHOR("Andrew Victor");
+MODULE_DESCRIPTION("Watchdog driver for KS8695");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:ks8695_wdt");