Fixed MTP to work with TWRP

drivers/watchdog/ixp4xx_wdt.c

@@ -0,0 +1,210 @@
+/*
+ * drivers/char/watchdog/ixp4xx_wdt.c
+ *
+ * Watchdog driver for Intel IXP4xx network processors
+ *
+ * Author: Deepak Saxena <dsaxena@plexity.net>
+ *
+ * Copyright 2004 (c) MontaVista, Software, Inc.
+ * Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
+ *
+ * This file is licensed under  the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <linux/uaccess.h>
+#include <mach/hardware.h>
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+static int heartbeat = 60;	/* (secs) Default is 1 minute */
+static unsigned long wdt_status;
+static unsigned long boot_status;
+static DEFINE_SPINLOCK(wdt_lock);
+
+#define WDT_TICK_RATE (IXP4XX_PERIPHERAL_BUS_CLOCK * 1000000UL)
+
+#define	WDT_IN_USE		0
+#define	WDT_OK_TO_CLOSE		1
+
+static void wdt_enable(void)
+{
+	spin_lock(&wdt_lock);
+	*IXP4XX_OSWK = IXP4XX_WDT_KEY;
+	*IXP4XX_OSWE = 0;
+	*IXP4XX_OSWT = WDT_TICK_RATE * heartbeat;
+	*IXP4XX_OSWE = IXP4XX_WDT_COUNT_ENABLE | IXP4XX_WDT_RESET_ENABLE;
+	*IXP4XX_OSWK = 0;
+	spin_unlock(&wdt_lock);
+}
+
+static void wdt_disable(void)
+{
+	spin_lock(&wdt_lock);
+	*IXP4XX_OSWK = IXP4XX_WDT_KEY;
+	*IXP4XX_OSWE = 0;
+	*IXP4XX_OSWK = 0;
+	spin_unlock(&wdt_lock);
+}
+
+static int ixp4xx_wdt_open(struct inode *inode, struct file *file)
+{
+	if (test_and_set_bit(WDT_IN_USE, &wdt_status))
+		return -EBUSY;
+
+	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+	wdt_enable();
+	return nonseekable_open(inode, file);
+}
+
+static ssize_t
+ixp4xx_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
+{
+	if (len) {
+		if (!nowayout) {
+			size_t i;
+
+			clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+
+			for (i = 0; i != len; i++) {
+				char c;
+
+				if (get_user(c, data + i))
+					return -EFAULT;
+				if (c == 'V')
+					set_bit(WDT_OK_TO_CLOSE, &wdt_status);
+			}
+		}
+		wdt_enable();
+	}
+	return len;
+}
+
+static const struct watchdog_info ident = {
+	.options	= WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
+			  WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+	.identity	= "IXP4xx Watchdog",
+};
+
+
+static long ixp4xx_wdt_ioctl(struct file *file, unsigned int cmd,
+							unsigned long arg)
+{
+	int ret = -ENOTTY;
+	int time;
+
+	switch (cmd) {
+	case WDIOC_GETSUPPORT:
+		ret = copy_to_user((struct watchdog_info *)arg, &ident,
+				   sizeof(ident)) ? -EFAULT : 0;
+		break;
+
+	case WDIOC_GETSTATUS:
+		ret = put_user(0, (int *)arg);
+		break;
+
+	case WDIOC_GETBOOTSTATUS:
+		ret = put_user(boot_status, (int *)arg);
+		break;
+
+	case WDIOC_KEEPALIVE:
+		wdt_enable();
+		ret = 0;
+		break;
+
+	case WDIOC_SETTIMEOUT:
+		ret = get_user(time, (int *)arg);
+		if (ret)
+			break;
+
+		if (time <= 0 || time > 60) {
+			ret = -EINVAL;
+			break;
+		}
+
+		heartbeat = time;
+		wdt_enable();
+		/* Fall through */
+
+	case WDIOC_GETTIMEOUT:
+		ret = put_user(heartbeat, (int *)arg);
+		break;
+	}
+	return ret;
+}
+
+static int ixp4xx_wdt_release(struct inode *inode, struct file *file)
+{
+	if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
+		wdt_disable();
+	else
+		pr_crit("Device closed unexpectedly - timer will not stop\n");
+	clear_bit(WDT_IN_USE, &wdt_status);
+	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+
+	return 0;
+}
+
+
+static const struct file_operations ixp4xx_wdt_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.write		= ixp4xx_wdt_write,
+	.unlocked_ioctl	= ixp4xx_wdt_ioctl,
+	.open		= ixp4xx_wdt_open,
+	.release	= ixp4xx_wdt_release,
+};
+
+static struct miscdevice ixp4xx_wdt_miscdev = {
+	.minor		= WATCHDOG_MINOR,
+	.name		= "watchdog",
+	.fops		= &ixp4xx_wdt_fops,
+};
+
+static int __init ixp4xx_wdt_init(void)
+{
+	int ret;
+
+	if (!(read_cpuid_id() & 0xf) && !cpu_is_ixp46x()) {
+		pr_err("Rev. A0 IXP42x CPU detected - watchdog disabled\n");
+
+		return -ENODEV;
+	}
+	boot_status = (*IXP4XX_OSST & IXP4XX_OSST_TIMER_WARM_RESET) ?
+			WDIOF_CARDRESET : 0;
+	ret = misc_register(&ixp4xx_wdt_miscdev);
+	if (ret == 0)
+		pr_info("timer heartbeat %d sec\n", heartbeat);
+	return ret;
+}
+
+static void __exit ixp4xx_wdt_exit(void)
+{
+	misc_deregister(&ixp4xx_wdt_miscdev);
+}
+
+
+module_init(ixp4xx_wdt_init);
+module_exit(ixp4xx_wdt_exit);
+
+MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
+MODULE_DESCRIPTION("IXP4xx Network Processor Watchdog");
+
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)");
+
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
+
+MODULE_LICENSE("GPL");