Add OMAP watchdog driver

Adds OMAP watchdog driver.
Signed-off-by: Tony Lindgren <tony@atomide.com>

drivers/char/watchdog/Kconfig

@@ -546,4 +546,11 @@ config USBPCWATCHDOG
 
 	  Most people will say N.
 
+config OMAP16XX_WATCHDOG
+	tristate "OMAP1610/OMAP1710 Watchdog"
+	depends on WATCHDOG && ARCH_OMAP16XX
+	help
+	  Support for TI OMAP1610/OMAP1710 watchdog. Say 'Y' here to enable the
+	  OMAP1610/OMAP1710 watchdog timer.
+
 endmenu

drivers/char/watchdog/Makefile

@@ -33,6 +33,7 @@ obj-$(CONFIG_USBPCWATCHDOG) += pcwd_usb.o
 obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o
 obj-$(CONFIG_IXP2000_WATCHDOG) += ixp2000_wdt.o
 obj-$(CONFIG_8xx_WDT) += mpc8xx_wdt.o
+obj-$(CONFIG_OMAP16XX_WATCHDOG) += omap1610_wdt.o
 
 # Only one watchdog can succeed. We probe the hardware watchdog
 # drivers first, then the softdog driver.  This means if your hardware

drivers/char/watchdog/omap1610_wdt.c

+/*
+ * linux/drivers/char/omap1610_wdt.c
+ *
+ * Watchdog driver for the TI OMAP
+ *
+ * Author: MontaVista Software, Inc.
+ *         <gdavis@mvista.com> or <source@mvista.com>
+ *
+ * 2003 (c) MontaVista Software, Inc. 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.
+ *
+ * History:
+ *
+ * 20030527: George G. Davis <gdavis@mvista.com>
+ *	Initially based on linux-2.4.19-rmk7-pxa1/drivers/char/sa1100_wdt.c
+ *	(c) Copyright 2000 Oleg Drokin <green@crimea.edu>
+ *	Based on SoftDog driver by Alan Cox <alan@redhat.com>
+ *
+ * Copyright (c) 2004 Texas Instruments.
+ *
+ * 1. Modified to support OMAP1610 32-KHz watchdog timer
+ * 2. Ported to 2.6 kernel
+ *
+ *
+ * TODO:
+ * 1. Need to disable watchdog when entering chip idle mode.
+ */
+
+#include <linux/module.h>
+#include <linux/config.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/err.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/hardware.h>
+#include <asm/bitops.h>
+#include <asm/hardware/clock.h>
+
+#include <linux/moduleparam.h>
+#include "omap1610_wdt.h"
+
+static int timer_margin;	/* in seconds */
+static int pre_margin;
+static int omap_wdt_users;
+static struct clk *armwdt_ck = 0;
+static struct miscdevice omap_wdt_miscdev; /* Forward declaration */
+
+static unsigned int wdt_trgr_pattern = 0x1234;
+
+static void
+omap_wdt_ping(void)
+{
+	while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x08) ;	/* wait for posted write to complete */
+	wdt_trgr_pattern = ~wdt_trgr_pattern;
+	omap_writel(wdt_trgr_pattern, (OMAP_WATCHDOG_TGR));
+	while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x08) ;	/* wait for posted write to complete */
+	return;
+}
+
+static void
+omap_wdt_enable(void)
+{
+	/* Sequence to enable the watchdog */
+	omap_writel(0xBBBB, OMAP_WATCHDOG_SPR);
+	while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x10) ;
+	omap_writel(0x4444, OMAP_WATCHDOG_SPR);
+	while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x10) ;
+	return;
+}
+
+static void
+omap_wdt_disable(void)
+{
+	/* sequence required to disable watchdog */
+	omap_writel(0xAAAA, OMAP_WATCHDOG_SPR);	/* TIMER_MODE */
+	while (omap_readl(OMAP_WATCHDOG_WPS) & 0x10) ;
+	omap_writel(0x5555, OMAP_WATCHDOG_SPR);	/* TIMER_MODE */
+	while (omap_readl(OMAP_WATCHDOG_WPS) & 0x10) ;
+	return;
+}
+
+/*
+ *	Allow only one person to hold it open
+ */
+
+static int
+omap_wdt_open(struct inode *inode, struct file *file)
+{
+	if (test_and_set_bit(1, (unsigned long *) &omap_wdt_users))
+		return -EBUSY;
+
+	if (armwdt_ck == 0 || IS_ERR(armwdt_ck)) {
+		armwdt_ck = clk_get(omap_wdt_miscdev.dev, "armwdt_ck");
+		if (IS_ERR(armwdt_ck)) {
+			omap_wdt_users = 0;
+			return PTR_ERR(armwdt_ck);
+		}
+		clk_use(armwdt_ck);	/* Enable the clock */
+	}
+
+	omap_wdt_enable();
+
+	return 0;
+}
+
+static int
+omap_wdt_release(struct inode *inode, struct file *file)
+{
+	/*
+	 *      Shut off the timer.
+	 *      Lock it in if it's a module and we defined ...NOWAYOUT
+	 */
+#ifndef CONFIG_WATCHDOG_NOWAYOUT
+	omap_wdt_disable();
+	clk_unuse(armwdt_ck);	/* Disable the clock */
+	clk_put(armwdt_ck);
+	armwdt_ck = 0;
+#endif
+	omap_wdt_users = 0;
+	return 0;
+}
+
+static ssize_t
+omap_wdt_write(struct file *file, const char *data, size_t len, loff_t * ppos)
+{
+	/*  Can't seek (pwrite) on this device  */
+	if (ppos != &file->f_pos)
+		return -ESPIPE;
+
+	/* Refresh LOAD_TIME. */
+	if (len) {
+		omap_wdt_ping();
+		return 1;
+	}
+	return 0;
+}
+
+static int
+omap_wdt_ioctl(struct inode *inode, struct file *file,
+	       unsigned int cmd, unsigned long arg)
+{
+	int new_margin;
+	static struct watchdog_info ident = {
+		.identity = "OMAP Watchdog",
+		.options = WDIOF_SETTIMEOUT,
+		.firmware_version = 0,
+	};
+
+	switch (cmd) {
+	default:
+		return -ENOIOCTLCMD;
+	case WDIOC_GETSUPPORT:
+		return copy_to_user((struct watchdog_info *) arg, &ident,
+				    sizeof (ident));
+	case WDIOC_GETSTATUS:
+		return put_user(0, (int *) arg);
+	case WDIOC_GETBOOTSTATUS:
+		return put_user(omap_readw(ARM_SYSST), (int *) arg);
+	case WDIOC_KEEPALIVE:
+		omap_wdt_ping();
+		return 0;
+	case WDIOC_SETTIMEOUT:
+		if (get_user(new_margin, (int *) arg))
+			return -EFAULT;
+		if ((new_margin < TIMER_MARGIN_MIN)
+		    || (new_margin > TIMER_MARGIN_MAX))
+			timer_margin = TIMER_MARGIN_MAX;	/* default timeout */
+		else
+			timer_margin = new_margin;
+		pre_margin = GET_WLDR_VAL(timer_margin);
+
+		omap_wdt_disable();
+
+		while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x04) ;	/* wait for posted write to complete */
+		omap_writel(pre_margin, (OMAP_WATCHDOG_LDR));
+		while ((omap_readl(OMAP_WATCHDOG_WPS)) & 0x04) ;	/* wait for posted write to complete */
+
+		omap_wdt_enable();
+
+		omap_wdt_ping();
+		/* Fall */
+	case WDIOC_GETTIMEOUT:
+		return put_user(timer_margin, (int *) arg);
+	}
+}
+
+static struct file_operations omap_wdt_fops = {
+	.owner = THIS_MODULE,
+	.write = omap_wdt_write,
+	.ioctl = omap_wdt_ioctl,
+	.open = omap_wdt_open,
+	.release = omap_wdt_release,
+};
+
+static struct miscdevice omap_wdt_miscdev = {
+	.minor = WATCHDOG_MINOR,
+	.name = "omap_wdt",
+	.fops = &omap_wdt_fops
+};
+
+static int __init
+omap_wdt_init(void)
+{
+	int ret;
+
+	ret = misc_register(&omap_wdt_miscdev);
+
+	if (ret)
+		return ret;
+
+	omap_wdt_disable();
+
+	if (timer_margin < 1 || timer_margin > 32)
+		timer_margin = 32;
+
+	printk(KERN_INFO "%s: TI OMAP Watchdog Timer: timer margin %d sec\n",
+	       omap_wdt_miscdev.name, timer_margin);
+
+	return 0;
+}
+
+static void __exit
+omap_wdt_exit(void)
+{
+	misc_deregister(&omap_wdt_miscdev);
+}
+
+module_init(omap_wdt_init);
+module_exit(omap_wdt_exit);
+
+MODULE_AUTHOR("George G. Davis");
+MODULE_LICENSE("GPL");
+module_param(timer_margin, int, 0);

drivers/char/watchdog/omap1610_wdt.h

+/*
+ *  linux/drivers/char/watchdog/omap1610_wdt.h
+ *
+ *  BRIEF MODULE DESCRIPTION
+ *      OMAP Watchdog timer register definitions
+ *
+ *  Copyright (C) 2004 Texas Instruments.
+ *
+ *  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.
+ *
+ *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
+ *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
+ *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
+ *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
+ *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
+ *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *  You should have received a copy of the  GNU General Public License along
+ *  with this program; if not, write  to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _OMAP_WATCHDOG_H
+#define _OMAP_WATCHDOG_H
+
+#define OMAP1610_WATCHDOG_BASE		0xfffeb000
+
+#define OMAP_WATCHDOG_BASE 		OMAP1610_WATCHDOG_BASE
+
+#define OMAP_WATCHDOG_REV		(OMAP_WATCHDOG_BASE + 0x00)
+#define OMAP_WATCHDOG_SYS_CONFIG	(OMAP_WATCHDOG_BASE + 0x10)
+#define OMAP_WATCHDOG_STATUS		(OMAP_WATCHDOG_BASE + 0x14)
+#define OMAP_WATCHDOG_CNTRL		(OMAP_WATCHDOG_BASE + 0x24)
+#define OMAP_WATCHDOG_CRR		(OMAP_WATCHDOG_BASE + 0x28)
+#define OMAP_WATCHDOG_LDR		(OMAP_WATCHDOG_BASE + 0x2c)
+#define OMAP_WATCHDOG_TGR		(OMAP_WATCHDOG_BASE + 0x30)
+#define OMAP_WATCHDOG_WPS		(OMAP_WATCHDOG_BASE + 0x34)
+#define OMAP_WATCHDOG_SPR		(OMAP_WATCHDOG_BASE + 0x48)
+
+#define TIMER_MARGIN_MAX    		32	/* Default is 32 seconds */
+#define TIMER_MARGIN_MIN		1
+
+#define GET_WLDR_VAL(x)			(0xffffffff - ((x) * 32768)) + 1
+
+#endif				/* _OMAP_WATCHDOG_H */