Commit 4a516539 authored by Viresh Kumar's avatar Viresh Kumar Committed by Wim Van Sebroeck
Browse files

watchdog: sp805_wdt: convert to watchdog core 



This patch converts existing sp805 watchdog driver to use already in place
common infrastructure present in watchdog core. With this lot of code goes away.

Signed-off-by: default avatarViresh Kumar <viresh.kumar@st.com>
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
parent 2d8c7ff5

drivers/watchdog/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -99,6 +99,7 @@ config WM8350_WATCHDOG 
config ARM_SP805_WATCHDOG

	tristate "ARM SP805 Watchdog"

	depends on ARM_AMBA

	select WATCHDOG_CORE

	help

	  ARM Primecell SP805 Watchdog timer. This will reboot your system when

	  the timeout is reached.

drivers/watchdog/sp805_wdt.c

+82 −159
Original line number Diff line number Diff line
@@ -16,20 +16,17 @@ 
#include <linux/amba/bus.h>

#include <linux/bitops.h>

#include <linux/clk.h>

#include <linux/fs.h>

#include <linux/init.h>

#include <linux/io.h>

#include <linux/ioport.h>

#include <linux/kernel.h>

#include <linux/math64.h>

#include <linux/miscdevice.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/pm.h>

#include <linux/slab.h>

#include <linux/spinlock.h>

#include <linux/types.h>

#include <linux/uaccess.h>

#include <linux/watchdog.h>



/* default timeout in seconds */
@@ -56,6 +53,7 @@ 


/**

 * struct sp805_wdt: sp805 wdt device structure

 * @wdd: instance of struct watchdog_device

 * @lock: spin lock protecting dev structure and io access

 * @base: base address of wdt

 * @clk: clock structure of wdt
@@ -65,24 +63,24 @@ 
 * @timeout: current programmed timeout

 */

struct sp805_wdt {

	struct watchdog_device		wdd;

	spinlock_t			lock;

	void __iomem			*base;

	struct clk			*clk;

	struct amba_device		*adev;

	unsigned long			status;

	#define WDT_BUSY		0

	#define WDT_CAN_BE_CLOSED	1

	unsigned int			load_val;

	unsigned int			timeout;

};



/* local variables */

static struct sp805_wdt *wdt;

static bool nowayout = WATCHDOG_NOWAYOUT;

module_param(nowayout, bool, 0);

MODULE_PARM_DESC(nowayout,

		"Set to 1 to keep watchdog running after device release");



/* This routine finds load value that will reset system in required timout */

static void wdt_setload(unsigned int timeout)

static int wdt_setload(struct watchdog_device *wdd, unsigned int timeout)

{

	struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);

	u64 load, rate;



	rate = clk_get_rate(wdt->clk);
@@ -103,11 +101,14 @@ static void wdt_setload(unsigned int timeout) 
	/* roundup timeout to closest positive integer value */

	wdt->timeout = div_u64((load + 1) * 2 + (rate / 2), rate);

	spin_unlock(&wdt->lock);



	return 0;

}



/* returns number of seconds left for reset to occur */

static u32 wdt_timeleft(void)

static unsigned int wdt_timeleft(struct watchdog_device *wdd)

{

	struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);

	u64 load, rate;



	rate = clk_get_rate(wdt->clk);
@@ -123,166 +124,88 @@ static u32 wdt_timeleft(void) 
	return div_u64(load, rate);

}



/* enables watchdog timers reset */

static void wdt_enable(void)

static int wdt_config(struct watchdog_device *wdd, bool ping)

{

	struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);

	int ret;



	if (!ping) {

		ret = clk_enable(wdt->clk);

		if (ret) {

			dev_err(&wdt->adev->dev, "clock enable fail");

			return ret;

		}

	}



	spin_lock(&wdt->lock);



	writel_relaxed(UNLOCK, wdt->base + WDTLOCK);

	writel_relaxed(wdt->load_val, wdt->base + WDTLOAD);

	writel_relaxed(INT_MASK, wdt->base + WDTINTCLR);

	writel_relaxed(INT_ENABLE | RESET_ENABLE, wdt->base + WDTCONTROL);

	writel_relaxed(LOCK, wdt->base + WDTLOCK);



	/* Flush posted writes. */

	readl_relaxed(wdt->base + WDTLOCK);

	spin_unlock(&wdt->lock);

	if (!ping) {

		writel_relaxed(INT_MASK, wdt->base + WDTINTCLR);

		writel_relaxed(INT_ENABLE | RESET_ENABLE, wdt->base +

				WDTCONTROL);

	}



/* disables watchdog timers reset */

static void wdt_disable(void)

{

	spin_lock(&wdt->lock);



	writel_relaxed(UNLOCK, wdt->base + WDTLOCK);

	writel_relaxed(0, wdt->base + WDTCONTROL);

	writel_relaxed(LOCK, wdt->base + WDTLOCK);



	/* Flush posted writes. */

	readl_relaxed(wdt->base + WDTLOCK);

	spin_unlock(&wdt->lock);

}



static ssize_t sp805_wdt_write(struct file *file, const char *data,

		size_t len, loff_t *ppos)

{

	if (len) {

		if (!nowayout) {

			size_t i;



			clear_bit(WDT_CAN_BE_CLOSED, &wdt->status);



			for (i = 0; i != len; i++) {

				char c;



				if (get_user(c, data + i))

					return -EFAULT;

				/* Check for Magic Close character */

				if (c == 'V') {

					set_bit(WDT_CAN_BE_CLOSED,

							&wdt->status);

					break;

				}

			}

		}

		wdt_enable();

	}

	return len;

	return 0;

}



static const struct watchdog_info ident = {

	.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,

	.identity = MODULE_NAME,

};



static long sp805_wdt_ioctl(struct file *file, unsigned int cmd,

		unsigned long arg)

static int wdt_ping(struct watchdog_device *wdd)

{

	int ret = -ENOTTY;

	unsigned int timeout;



	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_KEEPALIVE:

		wdt_enable();

		ret = 0;

		break;



	case WDIOC_SETTIMEOUT:

		ret = get_user(timeout, (unsigned int *)arg);

		if (ret)

			break;



		wdt_setload(timeout);



		wdt_enable();

		/* Fall through */



	case WDIOC_GETTIMEOUT:

		ret = put_user(wdt->timeout, (unsigned int *)arg);

		break;

	case WDIOC_GETTIMELEFT:

		ret = put_user(wdt_timeleft(), (unsigned int *)arg);

		break;

	}

	return ret;

	return wdt_config(wdd, true);

}



static int sp805_wdt_open(struct inode *inode, struct file *file)

/* enables watchdog timers reset */

static int wdt_enable(struct watchdog_device *wdd)

{

	int ret = 0;



	if (test_and_set_bit(WDT_BUSY, &wdt->status))

		return -EBUSY;



	ret = clk_enable(wdt->clk);

	if (ret) {

		dev_err(&wdt->adev->dev, "clock enable fail");

		goto err;

	return wdt_config(wdd, false);

}



	wdt_enable();

/* disables watchdog timers reset */

static int wdt_disable(struct watchdog_device *wdd)

{

	struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);



	/* can not be closed, once enabled */

	clear_bit(WDT_CAN_BE_CLOSED, &wdt->status);

	return nonseekable_open(inode, file);

	spin_lock(&wdt->lock);



err:

	clear_bit(WDT_BUSY, &wdt->status);

	return ret;

}

	writel_relaxed(UNLOCK, wdt->base + WDTLOCK);

	writel_relaxed(0, wdt->base + WDTCONTROL);

	writel_relaxed(LOCK, wdt->base + WDTLOCK);



static int sp805_wdt_release(struct inode *inode, struct file *file)

{

	if (!test_bit(WDT_CAN_BE_CLOSED, &wdt->status)) {

		clear_bit(WDT_BUSY, &wdt->status);

		dev_warn(&wdt->adev->dev, "Device closed unexpectedly\n");

		return 0;

	}

	/* Flush posted writes. */

	readl_relaxed(wdt->base + WDTLOCK);

	spin_unlock(&wdt->lock);



	wdt_disable();

	clk_disable(wdt->clk);

	clear_bit(WDT_BUSY, &wdt->status);



	return 0;

}



static const struct file_operations sp805_wdt_fops = {

	.owner = THIS_MODULE,

	.llseek = no_llseek,

	.write = sp805_wdt_write,

	.unlocked_ioctl = sp805_wdt_ioctl,

	.open = sp805_wdt_open,

	.release = sp805_wdt_release,

static const struct watchdog_info wdt_info = {

	.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,

	.identity = MODULE_NAME,

};



static struct miscdevice sp805_wdt_miscdev = {

	.minor = WATCHDOG_MINOR,

	.name = "watchdog",

	.fops = &sp805_wdt_fops,

static const struct watchdog_ops wdt_ops = {

	.owner		= THIS_MODULE,

	.start		= wdt_enable,

	.stop		= wdt_disable,

	.ping		= wdt_ping,

	.set_timeout	= wdt_setload,

	.get_timeleft	= wdt_timeleft,

};



static int __devinit

sp805_wdt_probe(struct amba_device *adev, const struct amba_id *id)

{

	struct sp805_wdt *wdt;

	int ret = 0;



	if (!devm_request_mem_region(&adev->dev, adev->res.start,
@@ -315,19 +238,26 @@ sp805_wdt_probe(struct amba_device *adev, const struct amba_id *id) 
	}



	wdt->adev = adev;

	wdt->wdd.info = &wdt_info;

	wdt->wdd.ops = &wdt_ops;



	spin_lock_init(&wdt->lock);

	wdt_setload(DEFAULT_TIMEOUT);

	watchdog_set_nowayout(&wdt->wdd, nowayout);

	watchdog_set_drvdata(&wdt->wdd, wdt);

	wdt_setload(&wdt->wdd, DEFAULT_TIMEOUT);



	ret = misc_register(&sp805_wdt_miscdev);

	if (ret < 0) {

		dev_warn(&adev->dev, "cannot register misc device\n");

		goto err_misc_register;

	ret = watchdog_register_device(&wdt->wdd);

	if (ret) {

		dev_err(&adev->dev, "watchdog_register_device() failed: %d\n",

				ret);

		goto err_register;

	}

	amba_set_drvdata(adev, wdt);



	dev_info(&adev->dev, "registration successful\n");

	return 0;



err_misc_register:

err_register:

	clk_put(wdt->clk);

err:

	dev_err(&adev->dev, "Probe Failed!!!\n");
@@ -336,7 +266,11 @@ sp805_wdt_probe(struct amba_device *adev, const struct amba_id *id) 


static int __devexit sp805_wdt_remove(struct amba_device *adev)

{

	misc_deregister(&sp805_wdt_miscdev);

	struct sp805_wdt *wdt = amba_get_drvdata(adev);



	watchdog_unregister_device(&wdt->wdd);

	amba_set_drvdata(adev, NULL);

	watchdog_set_drvdata(&wdt->wdd, NULL);

	clk_put(wdt->clk);



	return 0;
@@ -345,28 +279,22 @@ static int __devexit sp805_wdt_remove(struct amba_device *adev) 
#ifdef CONFIG_PM

static int sp805_wdt_suspend(struct device *dev)

{

	if (test_bit(WDT_BUSY, &wdt->status)) {

		wdt_disable();

		clk_disable(wdt->clk);

	}

	struct sp805_wdt *wdt = dev_get_drvdata(dev);



	if (watchdog_active(&wdt->wdd))

		return wdt_disable(&wdt->wdd);



	return 0;

}



static int sp805_wdt_resume(struct device *dev)

{

	int ret = 0;

	struct sp805_wdt *wdt = dev_get_drvdata(dev);



	if (test_bit(WDT_BUSY, &wdt->status)) {

		ret = clk_enable(wdt->clk);

		if (ret) {

			dev_err(dev, "clock enable fail");

			return ret;

		}

		wdt_enable();

	}

	if (watchdog_active(&wdt->wdd))

		return wdt_enable(&wdt->wdd);



	return ret;

	return 0;

}

#endif /* CONFIG_PM */
@@ -395,11 +323,6 @@ static struct amba_driver sp805_wdt_driver = { 


module_amba_driver(sp805_wdt_driver);



module_param(nowayout, bool, 0);

MODULE_PARM_DESC(nowayout,

		"Set to 1 to keep watchdog running after device release");



MODULE_AUTHOR("Viresh Kumar <viresh.kumar@st.com>");

MODULE_DESCRIPTION("ARM SP805 Watchdog Driver");

MODULE_LICENSE("GPL");
 
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);