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watchdog: Convert max63xx_wdt driver to watchdog framework
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This patch converts max63xx_wdt driver to watchdog framework.
Also use devm_* APIs to save a few error handling code.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
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Axel Lin authored and Wim Van Sebroeck committed Mar 27, 2012
1 parent 6b1e838 commit a0f3683
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Showing 2 changed files with 32 additions and 159 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 @@ -330,6 +330,7 @@ config TS72XX_WATCHDOG
config MAX63XX_WATCHDOG
tristate "Max63xx watchdog"
depends on ARM && HAS_IOMEM
select WATCHDOG_CORE
help
Support for memory mapped max63{69,70,71,72,73,74} watchdog timer.

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190 changes: 31 additions & 159 deletions drivers/watchdog/max63xx_wdt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -18,22 +18,19 @@
#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/platform_device.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/device.h>
#include <linux/slab.h>

#define DEFAULT_HEARTBEAT 60
#define MAX_HEARTBEAT 60

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

/*
Expand All @@ -45,15 +42,8 @@ static bool nowayout = WATCHDOG_NOWAYOUT;

static DEFINE_SPINLOCK(io_lock);

static unsigned long wdt_status;
#define WDT_IN_USE 0
#define WDT_RUNNING 1
#define WDT_OK_TO_CLOSE 2

static int nodelay;
static struct resource *wdt_mem;
static void __iomem *wdt_base;
static struct platform_device *max63xx_pdev;

/*
* The timeout values used are actually the absolute minimum the chip
Expand Down Expand Up @@ -117,7 +107,7 @@ max63xx_select_timeout(struct max63xx_timeout *table, int value)
return NULL;
}

static void max63xx_wdt_ping(void)
static int max63xx_wdt_ping(struct watchdog_device *wdd)
{
u8 val;

Expand All @@ -129,15 +119,14 @@ static void max63xx_wdt_ping(void)
__raw_writeb(val & ~MAX6369_WDI, wdt_base);

spin_unlock(&io_lock);
return 0;
}

static void max63xx_wdt_enable(struct max63xx_timeout *entry)
static int max63xx_wdt_start(struct watchdog_device *wdd)
{
struct max63xx_timeout *entry = watchdog_get_drvdata(wdd);
u8 val;

if (test_and_set_bit(WDT_RUNNING, &wdt_status))
return;

spin_lock(&io_lock);

val = __raw_readb(wdt_base);
Expand All @@ -149,10 +138,11 @@ static void max63xx_wdt_enable(struct max63xx_timeout *entry)

/* check for a edge triggered startup */
if (entry->tdelay == 0)
max63xx_wdt_ping();
max63xx_wdt_ping(wdd);
return 0;
}

static void max63xx_wdt_disable(void)
static int max63xx_wdt_stop(struct watchdog_device *wdd)
{
u8 val;

Expand All @@ -164,182 +154,64 @@ static void max63xx_wdt_disable(void)
__raw_writeb(val, wdt_base);

spin_unlock(&io_lock);

clear_bit(WDT_RUNNING, &wdt_status);
}

static int max63xx_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(WDT_IN_USE, &wdt_status))
return -EBUSY;

max63xx_wdt_enable(current_timeout);
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);

return nonseekable_open(inode, file);
}

static ssize_t max63xx_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);
}
}

max63xx_wdt_ping();
}

return len;
return 0;
}

static const struct watchdog_info ident = {
.options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
static const struct watchdog_info max63xx_wdt_info = {
.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "max63xx Watchdog",
};

static long max63xx_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int ret = -ENOTTY;

switch (cmd) {
case WDIOC_GETSUPPORT:
ret = copy_to_user((struct watchdog_info *)arg, &ident,
sizeof(ident)) ? -EFAULT : 0;
break;

case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
ret = put_user(0, (int *)arg);
break;

case WDIOC_KEEPALIVE:
max63xx_wdt_ping();
ret = 0;
break;

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

static int max63xx_wdt_release(struct inode *inode, struct file *file)
{
if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
max63xx_wdt_disable();
else
dev_crit(&max63xx_pdev->dev,
"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 max63xx_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = max63xx_wdt_write,
.unlocked_ioctl = max63xx_wdt_ioctl,
.open = max63xx_wdt_open,
.release = max63xx_wdt_release,
static const struct watchdog_ops max63xx_wdt_ops = {
.owner = THIS_MODULE,
.start = max63xx_wdt_start,
.stop = max63xx_wdt_stop,
.ping = max63xx_wdt_ping,
};

static struct miscdevice max63xx_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &max63xx_wdt_fops,
static struct watchdog_device max63xx_wdt_dev = {
.info = &max63xx_wdt_info,
.ops = &max63xx_wdt_ops,
};

static int __devinit max63xx_wdt_probe(struct platform_device *pdev)
{
int ret = 0;
int size;
struct device *dev = &pdev->dev;
struct resource *wdt_mem;
struct max63xx_timeout *table;

table = (struct max63xx_timeout *)pdev->id_entry->driver_data;

if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
heartbeat = DEFAULT_HEARTBEAT;

dev_info(dev, "requesting %ds heartbeat\n", heartbeat);
dev_info(&pdev->dev, "requesting %ds heartbeat\n", heartbeat);
current_timeout = max63xx_select_timeout(table, heartbeat);

if (!current_timeout) {
dev_err(dev, "unable to satisfy heartbeat request\n");
dev_err(&pdev->dev, "unable to satisfy heartbeat request\n");
return -EINVAL;
}

dev_info(dev, "using %ds heartbeat with %ds initial delay\n",
dev_info(&pdev->dev, "using %ds heartbeat with %ds initial delay\n",
current_timeout->twd, current_timeout->tdelay);

heartbeat = current_timeout->twd;

max63xx_pdev = pdev;

wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (wdt_mem == NULL) {
dev_err(dev, "failed to get memory region resource\n");
return -ENOENT;
}
wdt_base = devm_request_and_ioremap(&pdev->dev, wdt_mem);
if (!wdt_base)
return -ENOMEM;

size = resource_size(wdt_mem);
if (!request_mem_region(wdt_mem->start, size, pdev->name)) {
dev_err(dev, "failed to get memory region\n");
return -ENOENT;
}

wdt_base = ioremap(wdt_mem->start, size);
if (!wdt_base) {
dev_err(dev, "failed to map memory region\n");
ret = -ENOMEM;
goto out_request;
}
max63xx_wdt_dev.timeout = heartbeat;
watchdog_set_nowayout(&max63xx_wdt_dev, nowayout);
watchdog_set_drvdata(&max63xx_wdt_dev, current_timeout);

ret = misc_register(&max63xx_wdt_miscdev);
if (ret < 0) {
dev_err(dev, "cannot register misc device\n");
goto out_unmap;
}

return 0;

out_unmap:
iounmap(wdt_base);
out_request:
release_mem_region(wdt_mem->start, size);
wdt_mem = NULL;

return ret;
return watchdog_register_device(&max63xx_wdt_dev);
}

static int __devexit max63xx_wdt_remove(struct platform_device *pdev)
{
misc_deregister(&max63xx_wdt_miscdev);
if (wdt_mem) {
release_mem_region(wdt_mem->start, resource_size(wdt_mem));
wdt_mem = NULL;
}

if (wdt_base)
iounmap(wdt_base);

watchdog_unregister_device(&max63xx_wdt_dev);
return 0;
}

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