1 files changed, 330 insertions, 0 deletions
diff --git a/drivers/watchdog/ns9xxx_wdt.c b/drivers/watchdog/ns9xxx_wdt.c
new file mode 100644
index 000000000000..6234fbaa1609
--- /dev/null
+++ b/drivers/watchdog/ns9xxx_wdt.c
@@ -0,0 +1,330 @@
+/*
+ * drivers/watchdog/ns9xxx.c
+ *
+ * based on at91rm9200_wdt.c by Andrew Victor
+ *
+ * Copyright (C) 2009 Digi International Inc.
+ * 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 version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/io.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
+#include <linux/uaccess.h>
+#include <linux/watchdog.h>
+
+#define WDT_CONFIG			(0)
+#define WDT_TIMER			(4)
+
+#define WDT_CONFIG_ENABLE		(1 << 7)
+#define WDT_CONFIG_IRQCLEAR		(1 << 5)
+#define WDT_CONFIG_RESPONSE		(1 << 4)
+#define WDT_CONFIG_DIV64		(0x5)
+
+#define DRIVER_NAME			"ns9xxx-wdt"
+#define DEFAULT_TIME			10
+
+#define ns9xxx_wdt_pat()				\
+{							\
+	iowrite32(pdata.multiplier * timeout,		\
+			pdata.ioaddr + WDT_TIMER);	\
+}
+
+struct ns9xxx_wdt_pdata {
+	void __iomem		*ioaddr;
+	struct resource		*mem;
+	struct clk		*clk;
+
+	unsigned int		multiplier;
+	unsigned int		timeout_max;
+
+	unsigned long		busy;
+};
+
+static struct ns9xxx_wdt_pdata pdata;
+
+static unsigned int timeout = DEFAULT_TIME;
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog Timeout in seconds. "
+		"(default=" __MODULE_STRING(DEFAULT_TIME) ")");
+
+static struct watchdog_info ns9xxx_wdt_info = {
+	.identity	= "ns9xxx watchdog",
+	.options	= WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+};
+
+/* disable watchdog */
+static inline void ns9xxx_wdt_stop(void)
+{
+	unsigned long cfg;
+
+	/* watchdog cannot be disabled,
+	 * but stopped by clearing WDT_CONFIG_IRQCLEAR  */
+	cfg = ioread32(pdata.ioaddr + WDT_CONFIG) & ~WDT_CONFIG_IRQCLEAR;
+	iowrite32(cfg, pdata.ioaddr + WDT_CONFIG);
+}
+
+/* enable/reset watchdog */
+static inline void ns9xxx_wdt_start(void)
+{
+	ns9xxx_wdt_pat();
+
+	/* enable watchdog
+	 * reset interrupt
+	 * action = reset device
+	 * divisor = 64 (slowest)
+	 */
+	iowrite32(WDT_CONFIG_ENABLE | WDT_CONFIG_IRQCLEAR
+			| WDT_CONFIG_RESPONSE | WDT_CONFIG_DIV64,
+			pdata.ioaddr + WDT_CONFIG);
+}
+
+/* device is opened, start watchdog */
+static int ns9xxx_wdt_open(struct inode *inode, struct file *file)
+{
+	if (test_and_set_bit(0, &pdata.busy))
+		return -EBUSY;
+
+	ns9xxx_wdt_start();
+	return nonseekable_open(inode, file);
+}
+
+/* device is closed, watchdog will not(!) be disabled */
+static int ns9xxx_wdt_close(struct inode *inode, struct file *file)
+{
+	clear_bit(0, &pdata.busy);
+	return 0;
+}
+
+/* update the time interval */
+static int ns9xxx_wdt_settimeout(int new_time)
+{
+	/* skip check if we do not have a clock speed yet */
+	if ((new_time <= 0) || (new_time > pdata.timeout_max))
+		return -EINVAL;
+
+	timeout = new_time;
+	return 0;
+}
+
+/* handle ioctl */
+static int ns9xxx_wdt_ioctl(struct inode *inode, struct file *file,
+		unsigned int cmd, unsigned long arg)
+{
+	void __user *argp = (void __user *)arg;
+	int __user *p = argp;
+	int new_value;
+	int ret;
+
+	switch (cmd) {
+	case WDIOC_KEEPALIVE:
+		ns9xxx_wdt_pat();
+		return 0;
+	case WDIOC_GETSUPPORT:
+		return copy_to_user(argp, &ns9xxx_wdt_info,
+				sizeof(ns9xxx_wdt_info)) ? -EFAULT : 0;
+	case WDIOC_SETTIMEOUT:
+		if (get_user(new_value, p))
+			return -EFAULT;
+		ret = ns9xxx_wdt_settimeout(new_value);
+		if (ret)
+			return ret;
+		ns9xxx_wdt_start();
+		return put_user(timeout, p);
+	case WDIOC_GETTIMEOUT:
+		return put_user(timeout, p);
+	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_ENABLECARD)
+			ns9xxx_wdt_start();
+		return 0;
+	default:
+		return -ENOTTY;
+	}
+}
+
+/* pat watchdog on every write to the device */
+static ssize_t ns9xxx_wdt_write(struct file *file,
+		const char __user *data, size_t len, loff_t *ppos)
+{
+	ns9xxx_wdt_pat();
+	return len;
+}
+
+static const struct file_operations ns9xxx_wdt_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.ioctl		= ns9xxx_wdt_ioctl,
+	.open		= ns9xxx_wdt_open,
+	.release	= ns9xxx_wdt_close,
+	.write		= ns9xxx_wdt_write,
+};
+
+static struct miscdevice ns9xxx_wdt_miscdev = {
+	.minor		= WATCHDOG_MINOR,
+	.name		= DRIVER_NAME,
+	.fops		= &ns9xxx_wdt_fops,
+};
+
+static int __devinit ns9xxx_wdt_probe(struct platform_device *pdev)
+{
+	int ret;
+
+	if (ns9xxx_wdt_miscdev.parent)
+		return -EBUSY;
+
+	ns9xxx_wdt_miscdev.parent = &pdev->dev;
+
+	pdata.mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!pdata.mem) {
+		pr_err(DRIVER_NAME ": memory not available\n");
+		return -ENOENT;
+	}
+
+	if (!request_mem_region(pdata.mem->start,
+				pdata.mem->end - pdata.mem->start + 1,
+				DRIVER_NAME)) {
+		pr_err(DRIVER_NAME ": memory already mapped\n");
+		ret = -EIO;
+		goto err_mem;
+	}
+
+	pdata.ioaddr = ioremap(pdata.mem->start,
+			pdata.mem->end - pdata.mem->start + 1);
+	if (!pdata.ioaddr) {
+		pr_err(DRIVER_NAME ": unable to remap IO memory\n");
+		ret = -EIO;
+		goto err_remap;
+	}
+
+	pdata.clk = clk_get(&pdev->dev, DRIVER_NAME);
+	if (IS_ERR(pdata.clk)) {
+		pr_err(DRIVER_NAME ": clock not available\n");
+		ret = PTR_ERR(pdata.clk);
+		goto err_clk_get;
+	}
+
+	if (!clk_get_rate(pdata.clk)) {
+		pr_err(DRIVER_NAME ": cannot get clock rate\n");
+		ret = -EIO;
+		goto err_clk_rate;
+	}
+
+	/* calculate counter speed and maximum time
+	 * clock speed is cpu speed divided by 64 (slowest mode)
+	 * counter uses full 32bit register
+	 */
+
+	pdata.multiplier = clk_get_rate(pdata.clk) / 64;
+	pdata.timeout_max = 0;
+	pdata.timeout_max = ~pdata.timeout_max / pdata.multiplier;
+
+	/* recheck timeout for overflow */
+	ns9xxx_wdt_settimeout(timeout);
+
+	ret = misc_register(&ns9xxx_wdt_miscdev);
+	if (ret) {
+		pr_err(DRIVER_NAME ": cannot register misc device\n");
+		goto err_register;
+	}
+
+	dev_info(&pdev->dev, "NS9xxx watchdog timer at 0x%p\n",
+			pdata.ioaddr);
+	return 0;
+
+err_register:
+err_clk_rate:
+	clk_put(pdata.clk);
+err_clk_get:
+	iounmap(pdata.ioaddr);
+err_remap:
+	release_mem_region(pdata.mem->start,
+			 pdata.mem->end - pdata.mem->start + 1);
+err_mem:
+	release_resource(pdata.mem);
+
+	return ret;
+}
+
+static int __devexit ns9xxx_wdt_remove(struct platform_device *pdev)
+{
+	int res;
+
+	res = misc_deregister(&ns9xxx_wdt_miscdev);
+	if (!res)
+		ns9xxx_wdt_miscdev.parent = NULL;
+
+	return res;
+}
+
+static void ns9xxx_wdt_shutdown(struct platform_device *pdev)
+{
+	ns9xxx_wdt_stop();
+}
+
+#ifdef CONFIG_PM
+
+static int ns9xxx_wdt_suspend(struct platform_device *pdev,
+		pm_message_t message)
+{
+	ns9xxx_wdt_stop();
+	return 0;
+}
+
+static int ns9xxx_wdt_resume(struct platform_device *pdev)
+{
+	if (pdata.busy)
+		ns9xxx_wdt_start();
+	return 0;
+}
+
+#else
+# define ns9xxx_wdt_suspend NULL
+# define ns9xxx_wdt_resume	NULL
+#endif
+
+
+static struct platform_driver ns9xxx_wdt_driver = {
+	.probe		= ns9xxx_wdt_probe,
+	.remove		= __devexit_p(ns9xxx_wdt_remove),
+	.shutdown	= ns9xxx_wdt_shutdown,
+	.suspend	= ns9xxx_wdt_suspend,
+	.resume		= ns9xxx_wdt_resume,
+	.driver		= {
+		.name	= DRIVER_NAME,
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init ns9xxx_wdt_init(void)
+{
+	return platform_driver_register(&ns9xxx_wdt_driver);
+}
+
+static void __exit ns9xxx_wdt_exit(void)
+{
+	return platform_driver_unregister(&ns9xxx_wdt_driver);
+}
+
+module_init(ns9xxx_wdt_init);
+module_exit(ns9xxx_wdt_exit);
+
+MODULE_AUTHOR("Digi International Inc.");
+MODULE_DESCRIPTION("Digi NS9xxx Watchdog Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+MODULE_ALIAS("platform:" DRIVER_NAME);