1 files changed, 376 insertions, 0 deletions
diff --git a/drivers/watchdog/mxc_wdt.c b/drivers/watchdog/mxc_wdt.c
new file mode 100644
index 000000000000..eab9cecb9464
--- /dev/null
+++ b/drivers/watchdog/mxc_wdt.c
@@ -0,0 +1,376 @@
+/*
+ * linux/drivers/char/watchdog/mxc_wdt.c
+ *
+ * Watchdog driver for FSL MXC. It is based on omap1610_wdt.c
+ *
+ * Copyright (C) 2004-2010 Freescale Semiconductor, Inc.
+ * 2005 (c) MontaVista Software, Inc.
+
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * History:
+ *
+ * 20051207: <AKuster@mvista.com>
+ *	     	Full rewrite based on
+ *		linux-2.6.15-rc5/drivers/char/watchdog/omap_wdt.c
+ *	     	Add platform resource support
+ *
+ */
+
+/*!
+ * @defgroup WDOG Watchdog Timer (WDOG) Driver
+ */
+/*!
+ * @file mxc_wdt.c
+ *
+ * @brief Watchdog timer driver
+ *
+ * @ingroup WDOG
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+#include "mxc_wdt.h"
+
+#define DVR_VER "2.0"
+
+#define WDOG_SEC_TO_COUNT(s)  ((s * 2) << 8)
+#define WDOG_COUNT_TO_SEC(c)  ((c >> 8) / 2)
+
+static void __iomem  *wdt_base_reg;
+static int mxc_wdt_users;
+static struct clk *mxc_wdt_clk;
+
+static unsigned timer_margin = TIMER_MARGIN_DEFAULT;
+module_param(timer_margin, uint, 0);
+MODULE_PARM_DESC(timer_margin, "initial watchdog timeout (in seconds)");
+
+static unsigned dev_num;
+
+static void mxc_wdt_ping(void *base)
+{
+	/* issue the service sequence instructions */
+	__raw_writew(WDT_MAGIC_1, base + MXC_WDT_WSR);
+	__raw_writew(WDT_MAGIC_2, base + MXC_WDT_WSR);
+}
+
+static void mxc_wdt_config(void *base)
+{
+	u16 val;
+
+	val = __raw_readw(base + MXC_WDT_WCR);
+	val |= 0xFF00 | WCR_WOE_BIT | WCR_WDA_BIT | WCR_SRS_BIT;
+	/* enable suspend WDT */
+	val |= WCR_WDZST_BIT | WCR_WDBG_BIT;
+	/* generate reset if wdog times out */
+	val &= ~WCR_WRE_BIT;
+
+	__raw_writew(val, base + MXC_WDT_WCR);
+}
+
+static void mxc_wdt_enable(void *base)
+{
+	u16 val;
+
+	val = __raw_readw(base + MXC_WDT_WCR);
+	val |= WCR_WDE_BIT;
+	__raw_writew(val, base + MXC_WDT_WCR);
+}
+
+static void mxc_wdt_disable(void *base)
+{
+	/* disable not supported by this chip */
+}
+
+static void mxc_wdt_adjust_timeout(unsigned new_timeout)
+{
+	if (new_timeout < TIMER_MARGIN_MIN)
+		new_timeout = TIMER_MARGIN_DEFAULT;
+	if (new_timeout > TIMER_MARGIN_MAX)
+		new_timeout = TIMER_MARGIN_MAX;
+	timer_margin = new_timeout;
+}
+
+static u16 mxc_wdt_get_timeout(void *base)
+{
+	u16 val;
+
+	val = __raw_readw(base + MXC_WDT_WCR);
+	return WDOG_COUNT_TO_SEC(val);
+}
+
+static u16 mxc_wdt_get_bootreason(void *base)
+{
+	u16 val;
+
+	val = __raw_readw(base + MXC_WDT_WRSR);
+	return val;
+}
+
+static void mxc_wdt_set_timeout(void *base)
+{
+	u16 val;
+	val = __raw_readw(base + MXC_WDT_WCR);
+	val = (val & 0x00FF) | WDOG_SEC_TO_COUNT(timer_margin);
+	__raw_writew(val, base + MXC_WDT_WCR);
+	val = __raw_readw(base + MXC_WDT_WCR);
+	timer_margin = WDOG_COUNT_TO_SEC(val);
+}
+
+/*
+ *	Allow only one task to hold it open
+ */
+
+static int mxc_wdt_open(struct inode *inode, struct file *file)
+{
+
+	if (test_and_set_bit(1, (unsigned long *)&mxc_wdt_users))
+		return -EBUSY;
+
+	mxc_wdt_config(wdt_base_reg);
+	mxc_wdt_set_timeout(wdt_base_reg);
+	mxc_wdt_enable(wdt_base_reg);
+	mxc_wdt_ping(wdt_base_reg);
+
+	return 0;
+}
+
+static int mxc_wdt_release(struct inode *inode, struct file *file)
+{
+	/*
+	 *      Shut off the timer unless NOWAYOUT is defined.
+	 */
+#ifndef CONFIG_WATCHDOG_NOWAYOUT
+	mxc_wdt_disable(wdt_base_reg);
+
+#else
+	printk(KERN_CRIT "mxc_wdt: Unexpected close, not stopping!\n");
+#endif
+	mxc_wdt_users = 0;
+	return 0;
+}
+
+static ssize_t
+mxc_wdt_write(struct file *file, const char __user *data,
+	      size_t len, loff_t *ppos)
+{
+	/* Refresh LOAD_TIME. */
+	if (len)
+		mxc_wdt_ping(wdt_base_reg);
+	return len;
+}
+
+static int
+mxc_wdt_ioctl(struct inode *inode, struct file *file,
+	      unsigned int cmd, unsigned long arg)
+{
+	int new_margin;
+	int bootr;
+
+	static struct watchdog_info ident = {
+		.identity = "MXC Watchdog",
+		.options = WDIOF_SETTIMEOUT,
+		.firmware_version = 0,
+	};
+
+	switch (cmd) {
+	default:
+		return -ENOIOCTLCMD;
+	case WDIOC_GETSUPPORT:
+		return copy_to_user((struct watchdog_info __user *)arg, &ident,
+				    sizeof(ident));
+	case WDIOC_GETSTATUS:
+		return put_user(0, (int __user *)arg);
+	case WDIOC_GETBOOTSTATUS:
+		bootr = mxc_wdt_get_bootreason(wdt_base_reg);
+		return put_user(bootr, (int __user *)arg);
+	case WDIOC_KEEPALIVE:
+		mxc_wdt_ping(wdt_base_reg);
+		return 0;
+	case WDIOC_SETTIMEOUT:
+		if (get_user(new_margin, (int __user *)arg))
+			return -EFAULT;
+
+		mxc_wdt_adjust_timeout(new_margin);
+		mxc_wdt_disable(wdt_base_reg);
+		mxc_wdt_set_timeout(wdt_base_reg);
+		mxc_wdt_enable(wdt_base_reg);
+		mxc_wdt_ping(wdt_base_reg);
+		return 0;
+
+	case WDIOC_GETTIMEOUT:
+		mxc_wdt_ping(wdt_base_reg);
+		new_margin = mxc_wdt_get_timeout(wdt_base_reg);
+		return put_user(new_margin, (int __user *)arg);
+	}
+}
+
+static struct file_operations mxc_wdt_fops = {
+	.owner = THIS_MODULE,
+	.write = mxc_wdt_write,
+	.ioctl = mxc_wdt_ioctl,
+	.open = mxc_wdt_open,
+	.release = mxc_wdt_release,
+};
+
+static struct miscdevice mxc_wdt_miscdev = {
+	.minor = WATCHDOG_MINOR,
+	.name = "watchdog",
+	.fops = &mxc_wdt_fops
+};
+
+static int __init mxc_wdt_probe(struct platform_device *pdev)
+{
+	struct resource *res, *mem;
+	int ret;
+
+	/* reserve static register mappings */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, dev_num);
+	if (!res)
+		return -ENOENT;
+
+	mem = request_mem_region(res->start, res->end - res->start + 1,
+				 pdev->name);
+	if (mem == NULL)
+		return -EBUSY;
+
+	platform_set_drvdata(pdev, mem);
+
+	wdt_base_reg = ioremap(res->start, res->end - res->start + 1);
+	mxc_wdt_disable(wdt_base_reg);
+	mxc_wdt_adjust_timeout(timer_margin);
+
+	mxc_wdt_users = 0;
+
+	mxc_wdt_miscdev.this_device = &pdev->dev;
+
+	mxc_wdt_clk = clk_get(NULL, "wdog_clk");
+	clk_enable(mxc_wdt_clk);
+
+	ret = misc_register(&mxc_wdt_miscdev);
+	if (ret)
+		goto fail;
+
+	pr_info("MXC Watchdog # %d Timer: initial timeout %d sec\n", dev_num,
+		timer_margin);
+
+	return 0;
+
+      fail:
+	iounmap(wdt_base_reg);
+	release_resource(mem);
+	pr_info("MXC Watchdog Probe failed\n");
+	return ret;
+}
+
+static void mxc_wdt_shutdown(struct platform_device *pdev)
+{
+	mxc_wdt_disable(wdt_base_reg);
+	pr_info("MXC Watchdog # %d shutdown\n", dev_num);
+}
+
+static int __exit mxc_wdt_remove(struct platform_device *pdev)
+{
+	struct resource *mem = platform_get_drvdata(pdev);
+	misc_deregister(&mxc_wdt_miscdev);
+	iounmap(wdt_base_reg);
+	release_resource(mem);
+	pr_info("MXC Watchdog # %d removed\n", dev_num);
+	return 0;
+}
+
+#ifdef	CONFIG_PM
+
+/* REVISIT ... not clear this is the best way to handle system suspend; and
+ * it's very inappropriate for selective device suspend (e.g. suspending this
+ * through sysfs rather than by stopping the watchdog daemon).  Also, this
+ * may not play well enough with NOWAYOUT...
+ */
+
+static int mxc_wdt_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	if (mxc_wdt_users) {
+		mxc_wdt_disable(wdt_base_reg);
+	}
+	return 0;
+}
+
+static int mxc_wdt_resume(struct platform_device *pdev)
+{
+	if (mxc_wdt_users) {
+		mxc_wdt_enable(wdt_base_reg);
+		mxc_wdt_ping(wdt_base_reg);
+	}
+	return 0;
+}
+
+#else
+#define	mxc_wdt_suspend	NULL
+#define	mxc_wdt_resume		NULL
+#endif
+
+static struct platform_driver mxc_wdt_driver = {
+	.driver = {
+		   .owner = THIS_MODULE,
+		   .name = "mxc_wdt",
+		   },
+	.probe = mxc_wdt_probe,
+	.shutdown = mxc_wdt_shutdown,
+	.remove = __exit_p(mxc_wdt_remove),
+	.suspend = mxc_wdt_suspend,
+	.resume = mxc_wdt_resume,
+};
+
+static int __init mxc_wdt_init(void)
+{
+	pr_info("MXC WatchDog Driver %s\n", DVR_VER);
+
+	if ((timer_margin < TIMER_MARGIN_MIN) ||
+	    (timer_margin > TIMER_MARGIN_MAX)) {
+		pr_info("MXC watchdog error. wrong timer_margin %d\n",
+			timer_margin);
+		pr_info("    Range: %d to %d seconds\n", TIMER_MARGIN_MIN,
+			TIMER_MARGIN_MAX);
+		return -EINVAL;
+	}
+
+	return platform_driver_register(&mxc_wdt_driver);
+}
+
+static void __exit mxc_wdt_exit(void)
+{
+	platform_driver_unregister(&mxc_wdt_driver);
+	pr_info("MXC WatchDog Driver removed\n");
+}
+
+module_init(mxc_wdt_init);
+module_exit(mxc_wdt_exit);
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);