[PATCH] add SBC-FITPC2 watchdog driver

[Mike Rapoport <mike@compulab.co.il>]

> From: Denis Turischev <denis@compulab.co.il>

This patch adds support for watchdog found on SBC-FITPC2 board.

Signed-off-by: Denis Turischev <denis@compulab.co.il>
Signed-off-by: Mike Rapoport <mike@compulab.co.il>

diff -Nru linux-2.6.31-rc3.orig/drivers/watchdog/Kconfig linux-2.6.31-rc3/drivers/watchdog/Kconfig
--- linux-2.6.31-rc3.orig/drivers/watchdog/Kconfig	2009-07-14 04:18:52.000000000 +0300
+++ linux-2.6.31-rc3/drivers/watchdog/Kconfig	2009-07-16 13:52:08.000000000 +0300
@@ -721,6 +721,28 @@
 	  To compile this driver as a module, choose M here: the
 	  module will be called sbc_epx_c3.

+config SBC_FITPC2_WATCHDOG
+	tristate "Compulab SBC-FITPC2 watchdog"
+	depends on X86
+	---help---
+	  This is the driver for the built-in watchdog timer on the fit-PC2
+	  Single-board computer made by Compulab.
+
+	  It`s possible to enable watchdog timer either from BIOS (F2) or from booted Linux.
+	  When "Watchdog Timer Value" enabled one can set 31-255 s operational range.
+
+	  Entering BIOS setup temporary disables watchdog operation regardless to current state,
+	  so system will not be restarted while user in BIOS setup.
+
+	  Once watchdog was enabled the system will be restarted every
+	  "Watchdog Timer Value" period, so to prevent it user can restart or
+	  disable the watchdog.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called sbc_fitpc2_wdt.
+
+	  Most people will say N.
+
 # M32R Architecture

 # M68K Architecture
diff -Nru linux-2.6.31-rc3.orig/drivers/watchdog/Makefile linux-2.6.31-rc3/drivers/watchdog/Makefile
--- linux-2.6.31-rc3.orig/drivers/watchdog/Makefile	2009-07-14 04:18:52.000000000 +0300
+++ linux-2.6.31-rc3/drivers/watchdog/Makefile	2009-07-16 13:47:44.000000000 +0300
@@ -93,6 +93,7 @@
 obj-$(CONFIG_W83977F_WDT) += w83977f_wdt.o
 obj-$(CONFIG_MACHZ_WDT) += machzwd.o
 obj-$(CONFIG_SBC_EPX_C3_WATCHDOG) += sbc_epx_c3.o
+obj-$(CONFIG_SBC_FITPC2_WATCHDOG) += sbc_fitpc2_wdt.o

 # M32R Architecture

diff -Nru linux-2.6.31-rc3.orig/drivers/watchdog/sbc_fitpc2_wdt.c linux-2.6.31-rc3/drivers/watchdog/sbc_fitpc2_wdt.c
--- linux-2.6.31-rc3.orig/drivers/watchdog/sbc_fitpc2_wdt.c	1970-01-01 02:00:00.000000000 +0200
+++ linux-2.6.31-rc3/drivers/watchdog/sbc_fitpc2_wdt.c	2009-07-20 16:08:40.000000000 +0300
@@ -0,0 +1,240 @@
+/*
+ * Watchdog driver for SBC-FITPC2 board
+ *
+ * Author: Denis Turischev <denis@compulab.co.il>
+ *
+ * Adapted from the IXP2000 watchdog driver by Deepak Saxena.
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/ioport.h>
+#include <linux/delay.h>
+#include <linux/notifier.h>
+#include <linux/fs.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/dmi.h>
+
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <asm/system.h>
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+static unsigned int margin = 60;	/* (secs) Default is 1 minute */
+static unsigned long wdt_status;
+static spinlock_t wdt_lock;
+
+#define	WDT_IN_USE		0
+#define	WDT_OK_TO_CLOSE		1
+
+#define COMMAND_PORT		0x4c
+#define DATA_PORT		0x48
+
+#define IFACE_ON_COMMAND	1
+#define REBOOT_COMMAND		2
+
+#define WATCHDOG_NAME 		"SBC-FITPC2 Watchdog"
+
+static void wdt_send_data(unsigned char command, unsigned char data)
+{
+	outb(command, COMMAND_PORT);
+	mdelay(100);
+	outb(data, DATA_PORT);
+	mdelay(200);
+}
+
+static void wdt_enable(void)
+{
+	spin_lock(&wdt_lock);
+	wdt_send_data(IFACE_ON_COMMAND, 1);
+	wdt_send_data(REBOOT_COMMAND, margin);
+	spin_unlock(&wdt_lock);
+}
+
+static void wdt_disable(void)
+{
+	spin_lock(&wdt_lock);
+	wdt_send_data(IFACE_ON_COMMAND, 0);
+	wdt_send_data(REBOOT_COMMAND, 0);
+	spin_unlock(&wdt_lock);
+}
+
+static int fitpc2_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
+fitpc2_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 struct watchdog_info ident = {
+	.options	= WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
+				WDIOF_KEEPALIVEPING,
+	.identity	= WATCHDOG_NAME,
+};
+
+
+static long
+fitpc2_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(0, (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 < 31 || time > 255) {
+			ret = -EINVAL;
+			break;
+		}
+
+		margin = time;
+		wdt_enable();
+		/* Fall through */
+
+	case WDIOC_GETTIMEOUT:
+		ret = put_user(margin, (int *)arg);
+		break;
+	}
+
+	return ret;
+}
+
+static int fitpc2_wdt_release(struct inode *inode, struct file *file)
+{
+	if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) {
+		wdt_disable();
+		printk(KERN_CRIT "WATCHDOG: Device disabled\n");
+	} else {
+		printk(KERN_CRIT "WATCHDOG: 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 fitpc2_wdt_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.write		= fitpc2_wdt_write,
+	.unlocked_ioctl	= fitpc2_wdt_ioctl,
+	.open		= fitpc2_wdt_open,
+	.release	= fitpc2_wdt_release,
+};
+
+static struct miscdevice fitpc2_wdt_miscdev = {
+	.minor		= WATCHDOG_MINOR,
+	.name		= "watchdog",
+	.fops		= &fitpc2_wdt_fops,
+};
+
+static int __init fitpc2_wdt_init(void)
+{
+	if (strcmp("SBC-FITPC2", dmi_get_system_info(DMI_BOARD_NAME))) {
+		printk(KERN_CRIT "WATCHDOG: board name is: %s. Should be SBC-FITPC2\n",
+			dmi_get_system_info(DMI_BOARD_NAME));
+		return -ENODEV;
+	}
+
+	if (!request_region(COMMAND_PORT, 1, WATCHDOG_NAME)) {
+		printk(KERN_CRIT "WATCHDOG: I/O address 0x%04x already in use\n",
+			COMMAND_PORT);
+		return -EIO;
+	}
+	if (!request_region(DATA_PORT, 1, WATCHDOG_NAME)) {
+		printk(KERN_CRIT "WATCHDOG: I/O address 0x%04x already in use\n",
+			DATA_PORT);
+		return -EIO;
+	}
+
+	if (margin < 31 || margin > 255) {
+		printk(KERN_CRIT "WATCHDOG: margin must be in range 31 - 255"
+		" seconds, you tried to set %d\n", margin);
+		return -EINVAL;
+	}
+	return misc_register(&fitpc2_wdt_miscdev);
+}
+
+static void __exit fitpc2_wdt_exit(void)
+{
+	misc_deregister(&fitpc2_wdt_miscdev);
+}
+
+module_init(fitpc2_wdt_init);
+module_exit(fitpc2_wdt_exit);
+
+MODULE_AUTHOR("Denis Turischev <denis@compulab.co.il>");
+MODULE_DESCRIPTION("SBC-FITPC2 Watchdog");
+
+module_param(margin, int, 0);
+MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
+
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+


-- 
Sincerely yours,
Mike.