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Commit 4a516539 authored by Viresh Kumar's avatar Viresh Kumar Committed by Wim Van Sebroeck
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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
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+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.
+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 @@ err:

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);