Skip to content

Commit

Permalink
watchdog: imx2_wdt: convert to watchdog core api
Browse files Browse the repository at this point in the history
Convert the imx2_wdt driver to the new watchdog core api.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Cc: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
  • Loading branch information
Anatolij Gustschin authored and Wim Van Sebroeck committed Jun 10, 2014
1 parent a797700 commit faad5de
Showing 2 changed files with 123 additions and 170 deletions.
1 change: 1 addition & 0 deletions drivers/watchdog/Kconfig
Original file line number Diff line number Diff line change
@@ -379,6 +379,7 @@ config IMX2_WDT
tristate "IMX2+ Watchdog"
depends on ARCH_MXC
select REGMAP_MMIO
select WATCHDOG_CORE
help
This is the driver for the hardware watchdog
on the Freescale IMX2 and later processors.
292 changes: 122 additions & 170 deletions drivers/watchdog/imx2_wdt.c
Original file line number Diff line number Diff line change
@@ -22,18 +22,15 @@
*/

#include <linux/clk.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/timer.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>

#define DRIVER_NAME "imx2-wdt"
@@ -56,19 +53,12 @@

#define WDOG_SEC_TO_COUNT(s) ((s * 2 - 1) << 8)

#define IMX2_WDT_STATUS_OPEN 0
#define IMX2_WDT_STATUS_STARTED 1
#define IMX2_WDT_EXPECT_CLOSE 2

static struct {
struct imx2_wdt_device {
struct clk *clk;
struct regmap *regmap;
unsigned timeout;
unsigned long status;
struct timer_list timer; /* Pings the watchdog when closed */
} imx2_wdt;

static struct miscdevice imx2_wdt_miscdev;
struct watchdog_device wdog;
};

static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
@@ -86,11 +76,12 @@ static const struct watchdog_info imx2_wdt_info = {
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
};

static inline void imx2_wdt_setup(void)
static inline void imx2_wdt_setup(struct watchdog_device *wdog)
{
struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
u32 val;

regmap_read(imx2_wdt.regmap, IMX2_WDT_WCR, &val);
regmap_read(wdev->regmap, IMX2_WDT_WCR, &val);

/* Suspend timer in low power mode, write once-only */
val |= IMX2_WDT_WCR_WDZST;
@@ -101,157 +92,93 @@ static inline void imx2_wdt_setup(void)
/* Keep Watchdog Disabled */
val &= ~IMX2_WDT_WCR_WDE;
/* Set the watchdog's Time-Out value */
val |= WDOG_SEC_TO_COUNT(imx2_wdt.timeout);
val |= WDOG_SEC_TO_COUNT(wdog->timeout);

regmap_write(imx2_wdt.regmap, IMX2_WDT_WCR, val);
regmap_write(wdev->regmap, IMX2_WDT_WCR, val);

/* enable the watchdog */
val |= IMX2_WDT_WCR_WDE;
regmap_write(imx2_wdt.regmap, IMX2_WDT_WCR, val);
regmap_write(wdev->regmap, IMX2_WDT_WCR, val);
}

static inline void imx2_wdt_ping(void)
static inline bool imx2_wdt_is_running(struct imx2_wdt_device *wdev)
{
regmap_write(imx2_wdt.regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ1);
regmap_write(imx2_wdt.regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ2);
}
u32 val;

static void imx2_wdt_timer_ping(unsigned long arg)
{
/* ping it every imx2_wdt.timeout / 2 seconds to prevent reboot */
imx2_wdt_ping();
mod_timer(&imx2_wdt.timer, jiffies + imx2_wdt.timeout * HZ / 2);
regmap_read(wdev->regmap, IMX2_WDT_WCR, &val);

return val & IMX2_WDT_WCR_WDE;
}

static void imx2_wdt_start(void)
static int imx2_wdt_ping(struct watchdog_device *wdog)
{
if (!test_and_set_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
/* at our first start we enable clock and do initialisations */
clk_prepare_enable(imx2_wdt.clk);

imx2_wdt_setup();
} else /* delete the timer that pings the watchdog after close */
del_timer_sync(&imx2_wdt.timer);
struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);

/* Watchdog is enabled - time to reload the timeout value */
imx2_wdt_ping();
regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ1);
regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ2);
return 0;
}

static void imx2_wdt_stop(void)
static void imx2_wdt_timer_ping(unsigned long arg)
{
/* we don't need a clk_disable, it cannot be disabled once started.
* We use a timer to ping the watchdog while /dev/watchdog is closed */
imx2_wdt_timer_ping(0);
struct watchdog_device *wdog = (struct watchdog_device *)arg;
struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);

/* ping it every wdog->timeout / 2 seconds to prevent reboot */
imx2_wdt_ping(wdog);
mod_timer(&wdev->timer, jiffies + wdog->timeout * HZ / 2);
}

static void imx2_wdt_set_timeout(int new_timeout)
static int imx2_wdt_set_timeout(struct watchdog_device *wdog,
unsigned int new_timeout)
{
regmap_update_bits(imx2_wdt.regmap, IMX2_WDT_WCR, IMX2_WDT_WCR_WT,
struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);

regmap_update_bits(wdev->regmap, IMX2_WDT_WCR, IMX2_WDT_WCR_WT,
WDOG_SEC_TO_COUNT(new_timeout));
return 0;
}

static int imx2_wdt_open(struct inode *inode, struct file *file)
static int imx2_wdt_start(struct watchdog_device *wdog)
{
if (test_and_set_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status))
return -EBUSY;
struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);

imx2_wdt_start();
return nonseekable_open(inode, file);
if (imx2_wdt_is_running(wdev)) {
/* delete the timer that pings the watchdog after close */
del_timer_sync(&wdev->timer);
imx2_wdt_set_timeout(wdog, wdog->timeout);
} else
imx2_wdt_setup(wdog);

return imx2_wdt_ping(wdog);
}

static int imx2_wdt_close(struct inode *inode, struct file *file)
static int imx2_wdt_stop(struct watchdog_device *wdog)
{
if (test_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status) && !nowayout)
imx2_wdt_stop();
else {
dev_crit(imx2_wdt_miscdev.parent,
"Unexpected close: Expect reboot!\n");
imx2_wdt_ping();
}

clear_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
clear_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status);
/*
* We don't need a clk_disable, it cannot be disabled once started.
* We use a timer to ping the watchdog while /dev/watchdog is closed
*/
imx2_wdt_timer_ping((unsigned long)wdog);
return 0;
}

static long imx2_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
static inline void imx2_wdt_ping_if_active(struct watchdog_device *wdog)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
int new_value;
u32 val;
struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);

switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(argp, &imx2_wdt_info,
sizeof(struct watchdog_info)) ? -EFAULT : 0;

case WDIOC_GETSTATUS:
return put_user(0, p);

case WDIOC_GETBOOTSTATUS:
regmap_read(imx2_wdt.regmap, IMX2_WDT_WRSR, &val);
new_value = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0;
return put_user(new_value, p);

case WDIOC_KEEPALIVE:
imx2_wdt_ping();
return 0;

case WDIOC_SETTIMEOUT:
if (get_user(new_value, p))
return -EFAULT;
if ((new_value < 1) || (new_value > IMX2_WDT_MAX_TIME))
return -EINVAL;
imx2_wdt_set_timeout(new_value);
imx2_wdt.timeout = new_value;
imx2_wdt_ping();

/* Fallthrough to return current value */
case WDIOC_GETTIMEOUT:
return put_user(imx2_wdt.timeout, p);

default:
return -ENOTTY;
if (imx2_wdt_is_running(wdev)) {
imx2_wdt_set_timeout(wdog, wdog->timeout);
imx2_wdt_timer_ping((unsigned long)wdog);
}
}

static ssize_t imx2_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
size_t i;
char c;

if (len == 0) /* Can we see this even ? */
return 0;

clear_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
/* scan to see whether or not we got the magic character */
for (i = 0; i != len; i++) {
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
set_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
}

imx2_wdt_ping();
return len;
}

static const struct file_operations imx2_wdt_fops = {
static struct watchdog_ops imx2_wdt_ops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.unlocked_ioctl = imx2_wdt_ioctl,
.open = imx2_wdt_open,
.release = imx2_wdt_close,
.write = imx2_wdt_write,
};

static struct miscdevice imx2_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &imx2_wdt_fops,
.start = imx2_wdt_start,
.stop = imx2_wdt_stop,
.ping = imx2_wdt_ping,
.set_timeout = imx2_wdt_set_timeout,
};

static struct regmap_config imx2_wdt_regmap_config = {
@@ -263,76 +190,101 @@ static struct regmap_config imx2_wdt_regmap_config = {

static int __init imx2_wdt_probe(struct platform_device *pdev)
{
struct imx2_wdt_device *wdev;
struct watchdog_device *wdog;
struct resource *res;
void __iomem *base;
int ret;
u32 val;

wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL);
if (!wdev)
return -ENOMEM;

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(base))
return PTR_ERR(base);

imx2_wdt.regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
&imx2_wdt_regmap_config);
if (IS_ERR(imx2_wdt.regmap)) {
wdev->regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
&imx2_wdt_regmap_config);
if (IS_ERR(wdev->regmap)) {
dev_err(&pdev->dev, "regmap init failed\n");
return PTR_ERR(imx2_wdt.regmap);
return PTR_ERR(wdev->regmap);
}

imx2_wdt.clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(imx2_wdt.clk)) {
wdev->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(wdev->clk)) {
dev_err(&pdev->dev, "can't get Watchdog clock\n");
return PTR_ERR(imx2_wdt.clk);
return PTR_ERR(wdev->clk);
}

imx2_wdt.timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME);
if (imx2_wdt.timeout != timeout)
dev_warn(&pdev->dev, "Initial timeout out of range! "
"Clamped from %u to %u\n", timeout, imx2_wdt.timeout);
wdog = &wdev->wdog;
wdog->info = &imx2_wdt_info;
wdog->ops = &imx2_wdt_ops;
wdog->min_timeout = 1;
wdog->max_timeout = IMX2_WDT_MAX_TIME;

setup_timer(&imx2_wdt.timer, imx2_wdt_timer_ping, 0);
clk_prepare_enable(wdev->clk);

imx2_wdt_miscdev.parent = &pdev->dev;
ret = misc_register(&imx2_wdt_miscdev);
if (ret)
goto fail;
regmap_read(wdev->regmap, IMX2_WDT_WRSR, &val);
wdog->bootstatus = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0;

dev_info(&pdev->dev,
"IMX2+ Watchdog Timer enabled. timeout=%ds (nowayout=%d)\n",
imx2_wdt.timeout, nowayout);
return 0;
wdog->timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME);
if (wdog->timeout != timeout)
dev_warn(&pdev->dev, "Initial timeout out of range! Clamped from %u to %u\n",
timeout, wdog->timeout);

platform_set_drvdata(pdev, wdog);
watchdog_set_drvdata(wdog, wdev);
watchdog_set_nowayout(wdog, nowayout);
watchdog_init_timeout(wdog, timeout, &pdev->dev);

setup_timer(&wdev->timer, imx2_wdt_timer_ping, (unsigned long)wdog);

fail:
imx2_wdt_miscdev.parent = NULL;
return ret;
imx2_wdt_ping_if_active(wdog);

ret = watchdog_register_device(wdog);
if (ret) {
dev_err(&pdev->dev, "cannot register watchdog device\n");
return ret;
}

dev_info(&pdev->dev, "timeout %d sec (nowayout=%d)\n",
wdog->timeout, nowayout);

return 0;
}

static int __exit imx2_wdt_remove(struct platform_device *pdev)
{
misc_deregister(&imx2_wdt_miscdev);
struct watchdog_device *wdog = platform_get_drvdata(pdev);
struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);

if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
del_timer_sync(&imx2_wdt.timer);
watchdog_unregister_device(wdog);

dev_crit(imx2_wdt_miscdev.parent,
"Device removed: Expect reboot!\n");
if (imx2_wdt_is_running(wdev)) {
del_timer_sync(&wdev->timer);
imx2_wdt_ping(wdog);
dev_crit(&pdev->dev, "Device removed: Expect reboot!\n");
}

imx2_wdt_miscdev.parent = NULL;
return 0;
}

static void imx2_wdt_shutdown(struct platform_device *pdev)
{
if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
/* we are running, we need to delete the timer but will give
* max timeout before reboot will take place */
del_timer_sync(&imx2_wdt.timer);
imx2_wdt_set_timeout(IMX2_WDT_MAX_TIME);
imx2_wdt_ping();

dev_crit(imx2_wdt_miscdev.parent,
"Device shutdown: Expect reboot!\n");
struct watchdog_device *wdog = platform_get_drvdata(pdev);
struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);

if (imx2_wdt_is_running(wdev)) {
/*
* We are running, we need to delete the timer but will
* give max timeout before reboot will take place
*/
del_timer_sync(&wdev->timer);
imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
imx2_wdt_ping(wdog);
dev_crit(&pdev->dev, "Device shutdown: Expect reboot!\n");
}
}

0 comments on commit faad5de

Please sign in to comment.