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watchdog: pnx4008: convert driver to use the watchdog framework
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Make this driver a user of the watchdog framework and remove parts now handled
by the core. Tested on a custom lpc32xx-board.

[wim@iguana.be: Added set_timeout operation]
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
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Wolfram Sang authored and Wim Van Sebroeck committed Mar 27, 2012
1 parent 2e51d90 commit 6b1e838
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Showing 2 changed files with 41 additions and 140 deletions.
1 change: 1 addition & 0 deletions drivers/watchdog/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -235,6 +235,7 @@ config OMAP_WATCHDOG
config PNX4008_WATCHDOG
tristate "PNX4008 and LPC32XX Watchdog"
depends on ARCH_PNX4008 || ARCH_LPC32XX
select WATCHDOG_CORE
help
Say Y here if to include support for the watchdog timer
in the PNX4008 or LPC32XX processor.
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180 changes: 40 additions & 140 deletions drivers/watchdog/pnx4008_wdt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -8,10 +8,13 @@
* Based on sa1100 driver,
* Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
*
* 2005-2006 (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.
* 2005-2006 (c) MontaVista Software, Inc.
*
* (C) 2012 Wolfram Sang, Pengutronix
*
* 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
Expand All @@ -20,23 +23,17 @@
#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/ioport.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <mach/hardware.h>

#define MODULE_NAME "PNX4008-WDT: "

/* WatchDog Timer - Chapter 23 Page 207 */

#define DEFAULT_HEARTBEAT 19
Expand Down Expand Up @@ -80,19 +77,13 @@
#define WDOG_COUNTER_RATE 13000000 /*the counter clock is 13 MHz fixed */

static bool nowayout = WATCHDOG_NOWAYOUT;
static int heartbeat = DEFAULT_HEARTBEAT;
static unsigned int heartbeat = DEFAULT_HEARTBEAT;

static DEFINE_SPINLOCK(io_lock);
static unsigned long wdt_status;
#define WDT_IN_USE 0
#define WDT_OK_TO_CLOSE 1

static unsigned long boot_status;

static void __iomem *wdt_base;
struct clk *wdt_clk;

static void wdt_enable(void)
static int pnx4008_wdt_start(struct watchdog_device *wdd)
{
spin_lock(&io_lock);

Expand All @@ -109,144 +100,48 @@ static void wdt_enable(void)
writel(MATCH_INT, WDTIM_INT(wdt_base));
/* the longest pulse period 65541/(13*10^6) seconds ~ 5 ms. */
writel(0xFFFF, WDTIM_PULSE(wdt_base));
writel(heartbeat * WDOG_COUNTER_RATE, WDTIM_MATCH0(wdt_base));
writel(wdd->timeout * WDOG_COUNTER_RATE, WDTIM_MATCH0(wdt_base));
/*enable counter, stop when debugger active */
writel(COUNT_ENAB | DEBUG_EN, WDTIM_CTRL(wdt_base));

spin_unlock(&io_lock);
return 0;
}

static void wdt_disable(void)
static int pnx4008_wdt_stop(struct watchdog_device *wdd)
{
spin_lock(&io_lock);

writel(0, WDTIM_CTRL(wdt_base)); /*stop counter */

spin_unlock(&io_lock);
return 0;
}

static int pnx4008_wdt_open(struct inode *inode, struct file *file)
{
int ret;

if (test_and_set_bit(WDT_IN_USE, &wdt_status))
return -EBUSY;

clear_bit(WDT_OK_TO_CLOSE, &wdt_status);

ret = clk_enable(wdt_clk);
if (ret) {
clear_bit(WDT_IN_USE, &wdt_status);
return ret;
}

wdt_enable();

return nonseekable_open(inode, file);
}

static ssize_t pnx4008_wdt_write(struct file *file, const char *data,
size_t len, loff_t *ppos)
static int pnx4008_wdt_set_timeout(struct watchdog_device *wdd,
unsigned int new_timeout)
{
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;
return 0;
}

static const struct watchdog_info ident = {
static const struct watchdog_info pnx4008_wdt_ident = {
.options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = "PNX4008 Watchdog",
};

static long pnx4008_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 > MAX_HEARTBEAT) {
ret = -EINVAL;
break;
}

heartbeat = time;
wdt_enable();
/* Fall through */

case WDIOC_GETTIMEOUT:
ret = put_user(heartbeat, (int *)arg);
break;
}
return ret;
}

static int pnx4008_wdt_release(struct inode *inode, struct file *file)
{
if (!test_bit(WDT_OK_TO_CLOSE, &wdt_status))
pr_warn("Device closed unexpectedly\n");

wdt_disable();
clk_disable(wdt_clk);
clear_bit(WDT_IN_USE, &wdt_status);
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);

return 0;
}

static const struct file_operations pnx4008_wdt_fops = {
static const struct watchdog_ops pnx4008_wdt_ops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = pnx4008_wdt_write,
.unlocked_ioctl = pnx4008_wdt_ioctl,
.open = pnx4008_wdt_open,
.release = pnx4008_wdt_release,
.start = pnx4008_wdt_start,
.stop = pnx4008_wdt_stop,
.set_timeout = pnx4008_wdt_set_timeout,
};

static struct miscdevice pnx4008_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &pnx4008_wdt_fops,
static struct watchdog_device pnx4008_wdd = {
.info = &pnx4008_wdt_ident,
.ops = &pnx4008_wdt_ops,
.min_timeout = 1,
.max_timeout = MAX_HEARTBEAT,
};

static int __devinit pnx4008_wdt_probe(struct platform_device *pdev)
Expand All @@ -270,30 +165,34 @@ static int __devinit pnx4008_wdt_probe(struct platform_device *pdev)
if (ret)
goto out;

boot_status = (readl(WDTIM_RES(wdt_base)) & WDOG_RESET) ?
pnx4008_wdd.timeout = heartbeat;
pnx4008_wdd.bootstatus = (readl(WDTIM_RES(wdt_base)) & WDOG_RESET) ?
WDIOF_CARDRESET : 0;
wdt_disable(); /*disable for now */
clk_disable(wdt_clk);
watchdog_set_nowayout(&pnx4008_wdd, nowayout);

pnx4008_wdt_stop(&pnx4008_wdd); /* disable for now */

ret = misc_register(&pnx4008_wdt_miscdev);
ret = watchdog_register_device(&pnx4008_wdd);
if (ret < 0) {
dev_err(&pdev->dev, "cannot register misc device\n");
goto out;
dev_err(&pdev->dev, "cannot register watchdog device\n");
goto disable_clk;
}

dev_info(&pdev->dev, "PNX4008 Watchdog Timer: heartbeat %d sec\n",
heartbeat);

return 0;

disable_clk:
clk_disable(wdt_clk);
out:
clk_put(wdt_clk);
return ret;
}

static int __devexit pnx4008_wdt_remove(struct platform_device *pdev)
{
misc_deregister(&pnx4008_wdt_miscdev);
watchdog_unregister_device(&pnx4008_wdd);

clk_disable(wdt_clk);
clk_put(wdt_clk);
Expand All @@ -313,9 +212,10 @@ static struct platform_driver platform_wdt_driver = {
module_platform_driver(platform_wdt_driver);

MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>");
MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>");
MODULE_DESCRIPTION("PNX4008 Watchdog Driver");

module_param(heartbeat, int, 0);
module_param(heartbeat, uint, 0);
MODULE_PARM_DESC(heartbeat,
"Watchdog heartbeat period in seconds from 1 to "
__MODULE_STRING(MAX_HEARTBEAT) ", default "
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