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yaml
---
r: 309399
b: refs/heads/master
c: 4a51653
h: refs/heads/master
i:
  309397: d14f077
  309395: 408a652
  309391: 0b964b9
v: v3
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Viresh Kumar authored and Wim Van Sebroeck committed May 30, 2012
1 parent c7e37f9 commit 4b97bdb
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Showing 3 changed files with 84 additions and 160 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 2d8c7ff52c2459a25034ac8ddc230e67cc0e2b67
refs/heads/master: 4a516539faba13deca2399cff8faaa84d251a4ea
1 change: 1 addition & 0 deletions trunk/drivers/watchdog/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -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.
Expand Down
241 changes: 82 additions & 159 deletions trunk/drivers/watchdog/sp805_wdt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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 */
Expand All @@ -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
Expand All @@ -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);
Expand All @@ -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);
Expand All @@ -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);
}

/* disables watchdog timers reset */
static void wdt_disable(void)
{
spin_lock(&wdt->lock);
if (!ping) {
writel_relaxed(INT_MASK, wdt->base + WDTINTCLR);
writel_relaxed(INT_ENABLE | RESET_ENABLE, wdt->base +
WDTCONTROL);
}

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);

return 0;
}

static ssize_t sp805_wdt_write(struct file *file, const char *data,
size_t len, loff_t *ppos)
static int wdt_ping(struct watchdog_device *wdd)
{
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 wdt_config(wdd, true);
}

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)
/* enables watchdog timers reset */
static int wdt_enable(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, false);
}

static int sp805_wdt_open(struct inode *inode, struct file *file)
/* disables watchdog timers reset */
static int wdt_disable(struct watchdog_device *wdd)
{
int ret = 0;
struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);

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;
}

wdt_enable();

/* 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,
Expand Down Expand Up @@ -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");
Expand All @@ -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;
Expand All @@ -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 */

Expand Down Expand Up @@ -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);

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