[WATCHDOG] Add support for the IDT RC32434 watchdog

Add driver for the IDT RC32434 SoC built-in watchdog.

Signed-off-by: Florian Fainelli <florian.fainelli@telecomint.eu>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/Kconfig

@@ -643,6 +643,16 @@ config SBC_EPX_C3_WATCHDOG
 
 # MIPS Architecture
 
+config RC32434_WDT
+	tristate "IDT RC32434 SoC Watchdog Timer"
+	depends on MIKROTIK_RB532
+	help
+	  Hardware driver for the IDT RC32434 SoC built-in
+	  watchdog timer.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called rc32434_wdt.
+
 config INDYDOG
 	tristate "Indy/I2 Hardware Watchdog"
 	depends on SGI_HAS_INDYDOG

drivers/watchdog/Makefile

@@ -95,6 +95,7 @@ obj-$(CONFIG_SBC_EPX_C3_WATCHDOG) += sbc_epx_c3.o
 # M68KNOMMU Architecture
 
 # MIPS Architecture
+obj-$(CONFIG_RC32434_WDT) += rc32434_wdt.o
 obj-$(CONFIG_INDYDOG) += indydog.o
 obj-$(CONFIG_WDT_MTX1) += mtx-1_wdt.o
 obj-$(CONFIG_WDT_RM9K_GPI) += rm9k_wdt.o

drivers/watchdog/rc32434_wdt.c

@@ -0,0 +1,344 @@
+/*
+ *  IDT Interprise 79RC32434 watchdog driver
+ *
+ *  Copyright (C) 2006, Ondrej Zajicek <santiago@crfreenet.org>
+ *  Copyright (C) 2008, Florian Fainelli <florian@openwrt.org>
+ *
+ *  based on
+ *  SoftDog 0.05:	A Software Watchdog Device
+ *
+ *  (c) Copyright 1996 Alan Cox <alan@redhat.com>, 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.
+ *
+ */
+
+#include <linux/module.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/reboot.h>
+#include <linux/smp_lock.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/uaccess.h>
+
+#include <asm/bootinfo.h>
+#include <asm/time.h>
+#include <asm/mach-rc32434/integ.h>
+
+#define MAX_TIMEOUT			20
+#define RC32434_WDT_INTERVAL		(15 * HZ)
+
+#define VERSION "0.2"
+
+static struct {
+	struct completion stop;
+	int running;
+	struct timer_list timer;
+	int queue;
+	int default_ticks;
+	unsigned long inuse;
+} rc32434_wdt_device;
+
+static struct integ __iomem *wdt_reg;
+static int ticks = 100 * HZ;
+
+static int expect_close;
+static int timeout;
+
+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 void rc32434_wdt_start(void)
+{
+	u32 val;
+
+	if (!rc32434_wdt_device.inuse) {
+		writel(0, &wdt_reg->wtcount);
+
+		val = RC32434_ERR_WRE;
+		writel(readl(&wdt_reg->errcs) | val, &wdt_reg->errcs);
+
+		val = RC32434_WTC_EN;
+		writel(readl(&wdt_reg->wtc) | val, &wdt_reg->wtc);
+	}
+	rc32434_wdt_device.running++;
+}
+
+static void rc32434_wdt_stop(void)
+{
+	u32 val;
+
+	if (rc32434_wdt_device.running) {
+
+		val = ~RC32434_WTC_EN;
+		writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc);
+
+		val = ~RC32434_ERR_WRE;
+		writel(readl(&wdt_reg->errcs) & val, &wdt_reg->errcs);
+
+		rc32434_wdt_device.running = 0;
+	}
+}
+
+static void rc32434_wdt_set(int new_timeout)
+{
+	u32 cmp = new_timeout * HZ;
+	u32 state, val;
+
+	timeout = new_timeout;
+	/*
+	 * store and disable WTC
+	 */
+	state = (u32)(readl(&wdt_reg->wtc) & RC32434_WTC_EN);
+	val = ~RC32434_WTC_EN;
+	writel(readl(&wdt_reg->wtc) & val, &wdt_reg->wtc);
+
+	writel(0, &wdt_reg->wtcount);
+	writel(cmp, &wdt_reg->wtcompare);
+
+	/*
+	 * restore WTC
+	 */
+
+	writel(readl(&wdt_reg->wtc) | state, &wdt_reg);
+}
+
+static void rc32434_wdt_reset(void)
+{
+	ticks = rc32434_wdt_device.default_ticks;
+}
+
+static void rc32434_wdt_update(unsigned long unused)
+{
+	if (rc32434_wdt_device.running)
+		ticks--;
+
+	writel(0, &wdt_reg->wtcount);
+
+	if (rc32434_wdt_device.queue && ticks)
+		mod_timer(&rc32434_wdt_device.timer,
+			jiffies + RC32434_WDT_INTERVAL);
+	else
+		complete(&rc32434_wdt_device.stop);
+}
+
+static int rc32434_wdt_open(struct inode *inode, struct file *file)
+{
+	if (test_and_set_bit(0, &rc32434_wdt_device.inuse))
+		return -EBUSY;
+
+	if (nowayout)
+		__module_get(THIS_MODULE);
+
+	return nonseekable_open(inode, file);
+}
+
+static int rc32434_wdt_release(struct inode *inode, struct file *file)
+{
+	if (expect_close && nowayout == 0) {
+		rc32434_wdt_stop();
+		printk(KERN_INFO KBUILD_MODNAME ": disabling watchdog timer\n");
+		module_put(THIS_MODULE);
+	} else
+		printk(KERN_CRIT KBUILD_MODNAME
+			": device closed unexpectedly. WDT will not stop !\n");
+
+	clear_bit(0, &rc32434_wdt_device.inuse);
+	return 0;
+}
+
+static ssize_t rc32434_wdt_write(struct file *file, const char *data,
+				size_t len, loff_t *ppos)
+{
+	if (len) {
+		if (!nowayout) {
+			size_t i;
+
+			/* In case it was set long ago */
+			expect_close = 0;
+
+			for (i = 0; i != len; i++) {
+				char c;
+				if (get_user(c, data + i))
+					return -EFAULT;
+				if (c == 'V')
+					expect_close = 1;
+			}
+		}
+		rc32434_wdt_update(0);
+		return len;
+	}
+	return 0;
+}
+
+static int rc32434_wdt_ioctl(struct inode *inode, struct file *file,
+	unsigned int cmd, unsigned long arg)
+{
+	void __user *argp = (void __user *)arg;
+	int new_timeout;
+	unsigned int value;
+	static struct watchdog_info ident = {
+		.options =		WDIOF_SETTIMEOUT |
+					WDIOF_KEEPALIVEPING |
+					WDIOF_MAGICCLOSE,
+		.identity =		"RC32434_WDT Watchdog",
+	};
+	switch (cmd) {
+	case WDIOC_KEEPALIVE:
+		rc32434_wdt_reset();
+		break;
+	case WDIOC_GETSTATUS:
+	case WDIOC_GETBOOTSTATUS:
+		value = readl(&wdt_reg->wtcount);
+		if (copy_to_user(argp, &value, sizeof(int)))
+			return -EFAULT;
+		break;
+	case WDIOC_GETSUPPORT:
+		if (copy_to_user(argp, &ident, sizeof(ident)))
+			return -EFAULT;
+		break;
+	case WDIOC_SETOPTIONS:
+		if (copy_from_user(&value, argp, sizeof(int)))
+			return -EFAULT;
+		switch (value) {
+		case WDIOS_ENABLECARD:
+			rc32434_wdt_start();
+			break;
+		case WDIOS_DISABLECARD:
+			rc32434_wdt_stop();
+		default:
+			return -EINVAL;
+		}
+		break;
+	case WDIOC_SETTIMEOUT:
+		if (copy_from_user(&new_timeout, argp, sizeof(int)))
+			return -EFAULT;
+		if (new_timeout < 1)
+			return -EINVAL;
+		if (new_timeout > MAX_TIMEOUT)
+			return -EINVAL;
+		rc32434_wdt_set(new_timeout);
+	case WDIOC_GETTIMEOUT:
+		return copy_to_user(argp, &timeout, sizeof(int));
+	default:
+		return -ENOTTY;
+	}
+
+	return 0;
+}
+
+static struct file_operations rc32434_wdt_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.write		= rc32434_wdt_write,
+	.ioctl		= rc32434_wdt_ioctl,
+	.open		= rc32434_wdt_open,
+	.release	= rc32434_wdt_release,
+};
+
+static struct miscdevice rc32434_wdt_miscdev = {
+	.minor	= WATCHDOG_MINOR,
+	.name	= "watchdog",
+	.fops	= &rc32434_wdt_fops,
+};
+
+static char banner[] = KERN_INFO KBUILD_MODNAME
+		": Watchdog Timer version " VERSION ", timer margin: %d sec\n";
+
+static int rc32434_wdt_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct resource *r;
+
+	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rb500_wdt_res");
+	if (!r) {
+		printk(KERN_ERR KBUILD_MODNAME
+			"failed to retrieve resources\n");
+		return -ENODEV;
+	}
+
+	wdt_reg = ioremap_nocache(r->start, r->end - r->start);
+	if (!wdt_reg) {
+		printk(KERN_ERR KBUILD_MODNAME
+			"failed to remap I/O resources\n");
+		return -ENXIO;
+	}
+
+	ret = misc_register(&rc32434_wdt_miscdev);
+
+	if (ret < 0) {
+		printk(KERN_ERR KBUILD_MODNAME
+			"failed to register watchdog device\n");
+		goto unmap;
+	}
+
+	init_completion(&rc32434_wdt_device.stop);
+	rc32434_wdt_device.queue = 0;
+
+	clear_bit(0, &rc32434_wdt_device.inuse);
+
+	setup_timer(&rc32434_wdt_device.timer, rc32434_wdt_update, 0L);
+
+	rc32434_wdt_device.default_ticks = ticks;
+
+	rc32434_wdt_start();
+
+	printk(banner, timeout);
+
+	return 0;
+
+unmap:
+	iounmap(wdt_reg);
+	return ret;
+}
+
+static int rc32434_wdt_remove(struct platform_device *pdev)
+{
+	if (rc32434_wdt_device.queue) {
+		rc32434_wdt_device.queue = 0;
+		wait_for_completion(&rc32434_wdt_device.stop);
+	}
+	misc_deregister(&rc32434_wdt_miscdev);
+
+	iounmap(wdt_reg);
+
+	return 0;
+}
+
+static struct platform_driver rc32434_wdt = {
+	.probe	= rc32434_wdt_probe,
+	.remove = rc32434_wdt_remove,
+	.driver = {
+		.name = "rc32434_wdt",
+	}
+};
+
+static int __init rc32434_wdt_init(void)
+{
+	return platform_driver_register(&rc32434_wdt);
+}
+
+static void __exit rc32434_wdt_exit(void)
+{
+	platform_driver_unregister(&rc32434_wdt);
+}
+
+module_init(rc32434_wdt_init);
+module_exit(rc32434_wdt_exit);
+
+MODULE_AUTHOR("Ondrej Zajicek <santiago@crfreenet.org>,"
+		"Florian Fainelli <florian@openwrt.org>");
+MODULE_DESCRIPTION("Driver for the IDT RC32434 SoC watchdog");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);