[WATCHDOG] Add pnx833x_wdt

Add support for PNX833x watchdog timer.
Signed-off-by: Daniel Laird <daniel.j.laird@nxp.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/Kconfig

@@ -729,6 +729,15 @@ config WDT_MTX1
 	  Hardware driver for the MTX-1 boards. This is a watchdog timer that
 	  will reboot the machine after a 100 seconds timer expired.
 
+config PNX833X_WDT
+	tristate "PNX833x Hardware Watchdog"
+	depends on SOC_PNX8335
+	help
+	  Hardware driver for the PNX833x's watchdog. This is a
+	  watchdog timer that will reboot the machine after a programable
+	  timer has expired and no process has written to /dev/watchdog during
+	  that time.
+
 config WDT_RM9K_GPI
 	tristate "RM9000/GPI hardware watchdog"
 	depends on CPU_RM9000

drivers/watchdog/Makefile

@@ -101,6 +101,7 @@ obj-$(CONFIG_SBC_EPX_C3_WATCHDOG) += sbc_epx_c3.o
 obj-$(CONFIG_RC32434_WDT) += rc32434_wdt.o
 obj-$(CONFIG_INDYDOG) += indydog.o
 obj-$(CONFIG_WDT_MTX1) += mtx-1_wdt.o
+obj-$(CONFIG_PNX833X_WDT) += pnx833x_wdt.o
 obj-$(CONFIG_WDT_RM9K_GPI) += rm9k_wdt.o
 obj-$(CONFIG_SIBYTE_WDOG) += sb_wdog.o
 obj-$(CONFIG_AR7_WDT) += ar7_wdt.o

drivers/watchdog/pnx833x_wdt.c

+/*
+ *  PNX833x Hardware Watchdog Driver
+ *  Copyright 2008 NXP Semiconductors
+ *  Daniel Laird <daniel.j.laird@nxp.com>
+ *  Andre McCurdy <andre.mccurdy@nxp.com>
+ *
+ *  Heavily based upon - IndyDog	0.3
+ *  A Hardware Watchdog Device for SGI IP22
+ *
+ * (c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>, 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
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * based on softdog.c by Alan Cox <alan@redhat.com>
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <asm/mach-pnx833x/pnx833x.h>
+
+#define PFX "pnx833x: "
+#define WATCHDOG_TIMEOUT 30		/* 30 sec Maximum timeout */
+#define WATCHDOG_COUNT_FREQUENCY 68000000U /* Watchdog counts at 68MHZ. */
+
+/** CONFIG block */
+#define PNX833X_CONFIG                      (0x07000U)
+#define PNX833X_CONFIG_CPU_WATCHDOG         (0x54)
+#define PNX833X_CONFIG_CPU_WATCHDOG_COMPARE (0x58)
+#define PNX833X_CONFIG_CPU_COUNTERS_CONTROL (0x1c)
+
+/** RESET block */
+#define PNX833X_RESET                       (0x08000U)
+#define PNX833X_RESET_CONFIG                (0x08)
+
+static int pnx833x_wdt_alive;
+
+/* Set default timeout in MHZ.*/
+static int pnx833x_wdt_timeout = (WATCHDOG_TIMEOUT * WATCHDOG_COUNT_FREQUENCY);
+module_param(pnx833x_wdt_timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in Mhz. (68Mhz clock), default="
+			__MODULE_STRING(pnx833x_wdt_timeout) "(30 seconds).");
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+					__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static int start_enabled = 1;
+module_param(start_enabled, int, 0);
+MODULE_PARM_DESC(start_enabled, "Watchdog is started on module insertion "
+				"(default=" __MODULE_STRING(start_enabled) ")");
+
+static void pnx833x_wdt_start(void)
+{
+	/* Enable watchdog causing reset. */
+	PNX833X_REG(PNX833X_RESET + PNX833X_RESET_CONFIG) |= 0x1;
+	/* Set timeout.*/
+	PNX833X_REG(PNX833X_CONFIG +
+		PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout;
+	/* Enable watchdog. */
+	PNX833X_REG(PNX833X_CONFIG +
+				PNX833X_CONFIG_CPU_COUNTERS_CONTROL) |= 0x1;
+
+	printk(KERN_INFO PFX "Started watchdog timer.\n");
+}
+
+static void pnx833x_wdt_stop(void)
+{
+	/* Disable watchdog causing reset. */
+	PNX833X_REG(PNX833X_RESET + PNX833X_CONFIG) &= 0xFFFFFFFE;
+	/* Disable watchdog.*/
+	PNX833X_REG(PNX833X_CONFIG +
+			PNX833X_CONFIG_CPU_COUNTERS_CONTROL) &= 0xFFFFFFFE;
+
+	printk(KERN_INFO PFX "Stopped watchdog timer.\n");
+}
+
+static void pnx833x_wdt_ping(void)
+{
+	PNX833X_REG(PNX833X_CONFIG +
+		PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout;
+}
+
+/*
+ *	Allow only one person to hold it open
+ */
+static int pnx833x_wdt_open(struct inode *inode, struct file *file)
+{
+	if (test_and_set_bit(0, &pnx833x_wdt_alive))
+		return -EBUSY;
+
+	if (nowayout)
+		__module_get(THIS_MODULE);
+
+	/* Activate timer */
+	if (!start_enabled)
+		pnx833x_wdt_start();
+
+	pnx833x_wdt_ping();
+
+	printk(KERN_INFO "Started watchdog timer.\n");
+
+	return nonseekable_open(inode, file);
+}
+
+static int pnx833x_wdt_release(struct inode *inode, struct file *file)
+{
+	/* Shut off the timer.
+	 * Lock it in if it's a module and we defined ...NOWAYOUT */
+	if (!nowayout)
+		pnx833x_wdt_stop(); /* Turn the WDT off */
+
+	clear_bit(0, &pnx833x_wdt_alive);
+	return 0;
+}
+
+static ssize_t pnx833x_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
+{
+	/* Refresh the timer. */
+	if (len)
+		pnx833x_wdt_ping();
+
+	return len;
+}
+
+static long pnx833x_wdt_ioctl(struct file *file, unsigned int cmd,
+							unsigned long arg)
+{
+	int options, new_timeout = 0;
+	uint32_t timeout, timeout_left = 0;
+
+	static struct watchdog_info ident = {
+		.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
+		.firmware_version = 0,
+		.identity = "Hardware Watchdog for PNX833x",
+	};
+
+	switch (cmd) {
+	default:
+		return -ENOTTY;
+
+	case WDIOC_GETSUPPORT:
+		if (copy_to_user((struct watchdog_info *)arg,
+				 &ident, sizeof(ident)))
+			return -EFAULT;
+		return 0;
+
+	case WDIOC_GETSTATUS:
+	case WDIOC_GETBOOTSTATUS:
+		return put_user(0, (int *)arg);
+
+	case WDIOC_SETOPTIONS:
+		if (get_user(options, (int *)arg))
+			return -EFAULT;
+
+		if (options & WDIOS_DISABLECARD)
+			pnx833x_wdt_stop();
+
+		if (options & WDIOS_ENABLECARD)
+			pnx833x_wdt_start();
+
+		return 0;
+
+	case WDIOC_KEEPALIVE:
+		pnx833x_wdt_ping();
+		return 0;
+
+	case WDIOC_SETTIMEOUT:
+	{
+		if (get_user(new_timeout, (int *)arg))
+			return -EFAULT;
+
+		pnx833x_wdt_timeout = new_timeout;
+		PNX833X_REG(PNX833X_CONFIG +
+			PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = new_timeout;
+		return put_user(new_timeout, (int *)arg);
+	}
+
+	case WDIOC_GETTIMEOUT:
+		timeout = PNX833X_REG(PNX833X_CONFIG +
+					PNX833X_CONFIG_CPU_WATCHDOG_COMPARE);
+		return put_user(timeout, (int *)arg);
+
+	case WDIOC_GETTIMELEFT:
+		timeout_left = PNX833X_REG(PNX833X_CONFIG +
+						PNX833X_CONFIG_CPU_WATCHDOG);
+		return put_user(timeout_left, (int *)arg);
+
+	}
+}
+
+static int pnx833x_wdt_notify_sys(struct notifier_block *this,
+					unsigned long code, void *unused)
+{
+	if (code == SYS_DOWN || code == SYS_HALT)
+		pnx833x_wdt_stop(); /* Turn the WDT off */
+
+	return NOTIFY_DONE;
+}
+
+static const struct file_operations pnx833x_wdt_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.write		= pnx833x_wdt_write,
+	.unlocked_ioctl	= pnx833x_wdt_ioctl,
+	.open		= pnx833x_wdt_open,
+	.release	= pnx833x_wdt_release,
+};
+
+static struct miscdevice pnx833x_wdt_miscdev = {
+	.minor		= WATCHDOG_MINOR,
+	.name		= "watchdog",
+	.fops		= &pnx833x_wdt_fops,
+};
+
+static struct notifier_block pnx833x_wdt_notifier = {
+	.notifier_call = pnx833x_wdt_notify_sys,
+};
+
+static char banner[] __initdata =
+	KERN_INFO PFX "Hardware Watchdog Timer for PNX833x: Version 0.1\n";
+
+static int __init watchdog_init(void)
+{
+	int ret, cause;
+
+	/* Lets check the reason for the reset.*/
+	cause = PNX833X_REG(PNX833X_RESET);
+	/*If bit 31 is set then watchdog was cause of reset.*/
+	if (cause & 0x80000000) {
+		printk(KERN_INFO PFX "The system was previously reset due to "
+			"the watchdog firing - please investigate...\n");
+	}
+
+	ret = register_reboot_notifier(&pnx833x_wdt_notifier);
+	if (ret) {
+		printk(KERN_ERR PFX
+			"cannot register reboot notifier (err=%d)\n", ret);
+		return ret;
+	}
+
+	ret = misc_register(&pnx833x_wdt_miscdev);
+	if (ret) {
+		printk(KERN_ERR PFX
+			"cannot register miscdev on minor=%d (err=%d)\n",
+			WATCHDOG_MINOR, ret);
+		unregister_reboot_notifier(&pnx833x_wdt_notifier);
+		return ret;
+	}
+
+	printk(banner);
+	if (start_enabled)
+		pnx833x_wdt_start();
+
+	return 0;
+}
+
+static void __exit watchdog_exit(void)
+{
+	misc_deregister(&pnx833x_wdt_miscdev);
+	unregister_reboot_notifier(&pnx833x_wdt_notifier);
+}
+
+module_init(watchdog_init);
+module_exit(watchdog_exit);
+
+MODULE_AUTHOR("Daniel Laird/Andre McCurdy");
+MODULE_DESCRIPTION("Hardware Watchdog Device for PNX833x");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);