drivers/watchdog/Kconfig | 1 +
drivers/watchdog/dw_wdt.c | 316 +++++++++++++++++++---------------------------
2 files changed, 131 insertions(+), 186 deletions(-)
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 7a8a6c6..886468a 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -291,6 +291,7 @@ config SA1100_WATCHDOG
config DW_WATCHDOG
tristate "Synopsys DesignWare watchdog"
depends on HAS_IOMEM
+ select WATCHDOG_CORE
help
Say Y here if to include support for the Synopsys DesignWare
watchdog timer found in many chips.
diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
index 8fefa4ad..9e8706a 100644
--- a/drivers/watchdog/dw_wdt.c
+++ b/drivers/watchdog/dw_wdt.c
@@ -24,10 +24,8 @@
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
-#include <linux/fs.h>
#include <linux/io.h>
#include <linux/kernel.h>
-#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/notifier.h>
@@ -36,7 +34,6 @@
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/timer.h>
-#include <linux/uaccess.h>
#include <linux/watchdog.h>
#define WDOG_CONTROL_REG_OFFSET 0x00
@@ -59,59 +56,60 @@ MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
#define WDT_TIMEOUT (HZ / 2)
-static struct {
+struct dw_wdt_device {
void __iomem *regs;
struct clk *clk;
- unsigned long in_use;
- unsigned long next_heartbeat;
struct timer_list timer;
- int expect_close;
+ struct watchdog_device wdog;
struct notifier_block restart_handler;
-} dw_wdt;
+};
-static inline int dw_wdt_is_enabled(void)
+static inline bool dw_wdt_is_enabled(struct dw_wdt_device *wdev)
{
- return readl(dw_wdt.regs + WDOG_CONTROL_REG_OFFSET) &
+ return readl(wdev->regs + WDOG_CONTROL_REG_OFFSET) &
WDOG_CONTROL_REG_WDT_EN_MASK;
}
-static inline int dw_wdt_top_in_seconds(unsigned top)
+static inline unsigned int dw_wdt_top_in_seconds(struct dw_wdt_device *wdev,
+ unsigned int top)
{
/*
* There are 16 possible timeout values in 0..15 where the number of
* cycles is 2 ^ (16 + i) and the watchdog counts down.
*/
- return (1U << (16 + top)) / clk_get_rate(dw_wdt.clk);
+ return (1U << (16 + top)) / clk_get_rate(wdev->clk);
}
-static int dw_wdt_get_top(void)
+static unsigned int dw_wdt_get_timeleft(struct watchdog_device *wdog)
{
- int top = readl(dw_wdt.regs + WDOG_TIMEOUT_RANGE_REG_OFFSET) & 0xF;
+ struct dw_wdt_device *wdev = watchdog_get_drvdata(wdog);
- return dw_wdt_top_in_seconds(top);
+ return readl(wdev->regs + WDOG_CURRENT_COUNT_REG_OFFSET) /
+ clk_get_rate(wdev->clk);
}
-static inline void dw_wdt_set_next_heartbeat(void)
+static int dw_wdt_ping(struct watchdog_device *wdog)
{
- dw_wdt.next_heartbeat = jiffies + dw_wdt_get_top() * HZ;
-}
+ struct dw_wdt_device *wdev = watchdog_get_drvdata(wdog);
-static void dw_wdt_keepalive(void)
-{
- writel(WDOG_COUNTER_RESTART_KICK_VALUE, dw_wdt.regs +
+ writel(WDOG_COUNTER_RESTART_KICK_VALUE, wdev->regs +
WDOG_COUNTER_RESTART_REG_OFFSET);
+
+ return 0;
}
-static int dw_wdt_set_top(unsigned top_s)
+static int dw_wdt_set_timeout(struct watchdog_device *wdog,
+ unsigned int new_timeout)
{
- int i, top_val = DW_WDT_MAX_TOP;
+ unsigned int i, top_val = DW_WDT_MAX_TOP;
+ struct dw_wdt_device *wdev = watchdog_get_drvdata(wdog);
/*
* Iterate over the timeout values until we find the closest match. We
* always look for >=.
*/
for (i = 0; i <= DW_WDT_MAX_TOP; ++i)
- if (dw_wdt_top_in_seconds(i) >= top_s) {
+ if (dw_wdt_top_in_seconds(wdev, i) >= new_timeout) {
top_val = i;
break;
}
@@ -123,33 +121,34 @@ static int dw_wdt_set_top(unsigned top_s)
* effectively get a pat of the watchdog right here.
*/
writel(top_val | top_val << WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT,
- dw_wdt.regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
+ wdev->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
/*
* Add an explicit pat to handle versions of the watchdog that
* don't have TOPINIT. This won't hurt on versions that have
* it.
*/
- dw_wdt_keepalive();
-
- dw_wdt_set_next_heartbeat();
+ dw_wdt_ping(wdog);
- return dw_wdt_top_in_seconds(top_val);
+ return 0;
}
static int dw_wdt_restart_handle(struct notifier_block *this,
unsigned long mode, void *cmd)
{
u32 val;
+ struct dw_wdt_device *wdev = container_of(this,
+ struct dw_wdt_device,
+ restart_handler);
- writel(0, dw_wdt.regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
- val = readl(dw_wdt.regs + WDOG_CONTROL_REG_OFFSET);
+ writel(0, wdev->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
+ val = readl(wdev->regs + WDOG_CONTROL_REG_OFFSET);
if (val & WDOG_CONTROL_REG_WDT_EN_MASK)
- writel(WDOG_COUNTER_RESTART_KICK_VALUE, dw_wdt.regs +
+ writel(WDOG_COUNTER_RESTART_KICK_VALUE, wdev->regs +
WDOG_COUNTER_RESTART_REG_OFFSET);
else
writel(WDOG_CONTROL_REG_WDT_EN_MASK,
- dw_wdt.regs + WDOG_CONTROL_REG_OFFSET);
+ wdev->regs + WDOG_CONTROL_REG_OFFSET);
/* wait for reset to assert... */
mdelay(500);
@@ -157,74 +156,52 @@ static int dw_wdt_restart_handle(struct notifier_block *this,
return NOTIFY_DONE;
}
-static void dw_wdt_ping(unsigned long data)
+static void dw_wdt_timer_ping(unsigned long arg)
{
- if (time_before(jiffies, dw_wdt.next_heartbeat) ||
- (!nowayout && !dw_wdt.in_use)) {
- dw_wdt_keepalive();
- mod_timer(&dw_wdt.timer, jiffies + WDT_TIMEOUT);
- } else
- pr_crit("keepalive missed, machine will reset\n");
+ struct watchdog_device *wdog = (struct watchdog_device *)arg;
+ struct dw_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+ /* ping it every wdog->timeout / 2 seconds to prevent reboot */
+ dw_wdt_ping(wdog);
+ mod_timer(&wdev->timer, jiffies + wdog->timeout * HZ / 2);
}
-static int dw_wdt_open(struct inode *inode, struct file *filp)
+static int dw_wdt_start(struct watchdog_device *wdog)
{
- if (test_and_set_bit(0, &dw_wdt.in_use))
- return -EBUSY;
-
- /* Make sure we don't get unloaded. */
- __module_get(THIS_MODULE);
-
- if (!dw_wdt_is_enabled()) {
- /*
- * The watchdog is not currently enabled. Set the timeout to
- * something reasonable and then start it.
- */
- dw_wdt_set_top(DW_WDT_DEFAULT_SECONDS);
+ struct dw_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+ if (!dw_wdt_is_enabled(wdev)) {
+ dw_wdt_set_timeout(wdog, wdog->timeout);
writel(WDOG_CONTROL_REG_WDT_EN_MASK,
- dw_wdt.regs + WDOG_CONTROL_REG_OFFSET);
+ wdev->regs + WDOG_CONTROL_REG_OFFSET);
+ } else {
+ /* delete the timer that pings the watchdog after close */
+ del_timer_sync(&wdev->timer);
+ dw_wdt_set_timeout(wdog, wdog->timeout);
}
- dw_wdt_set_next_heartbeat();
-
- return nonseekable_open(inode, filp);
+ return 0;
}
-static ssize_t dw_wdt_write(struct file *filp, const char __user *buf,
- size_t len, loff_t *offset)
+static int dw_wdt_stop(struct watchdog_device *wdog)
{
- if (!len)
- return 0;
-
- if (!nowayout) {
- size_t i;
-
- dw_wdt.expect_close = 0;
-
- for (i = 0; i < len; ++i) {
- char c;
-
- if (get_user(c, buf + i))
- return -EFAULT;
-
- if (c == 'V') {
- dw_wdt.expect_close = 1;
- break;
- }
- }
- }
-
- dw_wdt_set_next_heartbeat();
- dw_wdt_keepalive();
- mod_timer(&dw_wdt.timer, jiffies + WDT_TIMEOUT);
-
- return len;
+ /*
+ * We don't need a clk_disable_unprepare, the wdt cannot be disabled
+ * once started. We use a timer to ping the watchdog while the
+ * /dev/watchdog is closed
+ */
+ dw_wdt_timer_ping((unsigned long)wdog);
+ return 0;
}
-static u32 dw_wdt_time_left(void)
+static inline void dw_wdt_ping_if_active(struct watchdog_device *wdog)
{
- return readl(dw_wdt.regs + WDOG_CURRENT_COUNT_REG_OFFSET) /
- clk_get_rate(dw_wdt.clk);
+ struct dw_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+ if (dw_wdt_is_enabled(wdev)) {
+ dw_wdt_set_timeout(wdog, wdog->timeout);
+ dw_wdt_timer_ping((unsigned long)wdog);
+ }
}
static const struct watchdog_info dw_wdt_ident = {
@@ -233,78 +210,37 @@ static const struct watchdog_info dw_wdt_ident = {
.identity = "Synopsys DesignWare Watchdog",
};
-static long dw_wdt_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
-{
- unsigned long val;
- int timeout;
-
- switch (cmd) {
- case WDIOC_GETSUPPORT:
- return copy_to_user((void __user *)arg, &dw_wdt_ident,
- sizeof(dw_wdt_ident)) ? -EFAULT : 0;
-
- case WDIOC_GETSTATUS:
- case WDIOC_GETBOOTSTATUS:
- return put_user(0, (int __user *)arg);
-
- case WDIOC_KEEPALIVE:
- dw_wdt_set_next_heartbeat();
- return 0;
-
- case WDIOC_SETTIMEOUT:
- if (get_user(val, (int __user *)arg))
- return -EFAULT;
- timeout = dw_wdt_set_top(val);
- return put_user(timeout , (int __user *)arg);
-
- case WDIOC_GETTIMEOUT:
- return put_user(dw_wdt_get_top(), (int __user *)arg);
-
- case WDIOC_GETTIMELEFT:
- /* Get the time left until expiry. */
- if (get_user(val, (int __user *)arg))
- return -EFAULT;
- return put_user(dw_wdt_time_left(), (int __user *)arg);
-
- default:
- return -ENOTTY;
- }
-}
-
-static int dw_wdt_release(struct inode *inode, struct file *filp)
-{
- clear_bit(0, &dw_wdt.in_use);
-
- if (!dw_wdt.expect_close) {
- del_timer(&dw_wdt.timer);
-
- if (!nowayout)
- pr_crit("unexpected close, system will reboot soon\n");
- else
- pr_crit("watchdog cannot be disabled, system will reboot soon\n");
- }
-
- dw_wdt.expect_close = 0;
-
- return 0;
-}
+static const struct watchdog_ops dw_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = dw_wdt_start,
+ .stop = dw_wdt_stop,
+ .ping = dw_wdt_ping,
+ .set_timeout = dw_wdt_set_timeout,
+ .get_timeleft = dw_wdt_get_timeleft,
+};
#ifdef CONFIG_PM_SLEEP
static int dw_wdt_suspend(struct device *dev)
{
- clk_disable_unprepare(dw_wdt.clk);
+ struct watchdog_device *wdog = dev_get_drvdata(dev);
+ struct dw_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+ clk_disable_unprepare(wdev->clk);
return 0;
}
static int dw_wdt_resume(struct device *dev)
{
- int err = clk_prepare_enable(dw_wdt.clk);
+ struct watchdog_device *wdog = dev_get_drvdata(dev);
+ struct dw_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+ int err = clk_prepare_enable(wdev->clk);
if (err)
return err;
- dw_wdt_keepalive();
+ dw_wdt_ping(wdog);
return 0;
}
@@ -312,67 +248,75 @@ static int dw_wdt_resume(struct device *dev)
static SIMPLE_DEV_PM_OPS(dw_wdt_pm_ops, dw_wdt_suspend, dw_wdt_resume);
-static const struct file_operations wdt_fops = {
- .owner = THIS_MODULE,
- .llseek = no_llseek,
- .open = dw_wdt_open,
- .write = dw_wdt_write,
- .unlocked_ioctl = dw_wdt_ioctl,
- .release = dw_wdt_release
-};
-
-static struct miscdevice dw_wdt_miscdev = {
- .fops = &wdt_fops,
- .name = "watchdog",
- .minor = WATCHDOG_MINOR,
-};
-
static int dw_wdt_drv_probe(struct platform_device *pdev)
{
int ret;
- struct resource *mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-
- dw_wdt.regs = devm_ioremap_resource(&pdev->dev, mem);
- if (IS_ERR(dw_wdt.regs))
- return PTR_ERR(dw_wdt.regs);
-
- dw_wdt.clk = devm_clk_get(&pdev->dev, NULL);
- if (IS_ERR(dw_wdt.clk))
- return PTR_ERR(dw_wdt.clk);
-
- ret = clk_prepare_enable(dw_wdt.clk);
+ struct dw_wdt_device *wdev;
+ struct watchdog_device *wdog;
+ struct resource *mem;
+
+ wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL);
+ if (!wdev)
+ return -ENOMEM;
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ wdev->regs = devm_ioremap_resource(&pdev->dev, mem);
+ if (IS_ERR(wdev->regs))
+ return PTR_ERR(wdev->regs);
+
+ wdev->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(wdev->clk))
+ return PTR_ERR(wdev->clk);
+
+ wdog = &wdev->wdog;
+ wdog->info = &dw_wdt_ident;
+ wdog->ops = &dw_wdt_ops;
+ wdog->min_timeout = dw_wdt_top_in_seconds(wdev, 0);
+ wdog->max_timeout = dw_wdt_top_in_seconds(wdev, DW_WDT_MAX_TOP);
+
+ ret = clk_prepare_enable(wdev->clk);
if (ret)
return ret;
- ret = misc_register(&dw_wdt_miscdev);
- if (ret)
- goto out_disable_clk;
+ platform_set_drvdata(pdev, wdog);
+ watchdog_set_drvdata(wdog, wdev);
+ watchdog_set_nowayout(wdog, nowayout);
+ watchdog_init_timeout(wdog, wdog->max_timeout, &pdev->dev);
- dw_wdt.restart_handler.notifier_call = dw_wdt_restart_handle;
- dw_wdt.restart_handler.priority = 128;
- ret = register_restart_handler(&dw_wdt.restart_handler);
+ wdev->restart_handler.notifier_call = dw_wdt_restart_handle;
+ wdev->restart_handler.priority = 128;
+ ret = register_restart_handler(&wdev->restart_handler);
if (ret)
- pr_warn("cannot register restart handler\n");
+ dev_warn(&pdev->dev, "cannot register restart handler\n");
- dw_wdt_set_next_heartbeat();
- setup_timer(&dw_wdt.timer, dw_wdt_ping, 0);
- mod_timer(&dw_wdt.timer, jiffies + WDT_TIMEOUT);
+ setup_timer(&wdev->timer, dw_wdt_timer_ping, (unsigned long)wdog);
+
+ dw_wdt_ping_if_active(wdog);
+
+ ret = watchdog_register_device(wdog);
+ if (ret) {
+ dev_err(&pdev->dev, "cannot register watchdog device\n");
+ goto out_disable_clk;
+ }
return 0;
out_disable_clk:
- clk_disable_unprepare(dw_wdt.clk);
+ clk_disable_unprepare(wdev->clk);
return ret;
}
static int dw_wdt_drv_remove(struct platform_device *pdev)
{
- unregister_restart_handler(&dw_wdt.restart_handler);
+ struct watchdog_device *wdog = platform_get_drvdata(pdev);
+ struct dw_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+ unregister_restart_handler(&wdev->restart_handler);
- misc_deregister(&dw_wdt_miscdev);
+ watchdog_unregister_device(wdog);
- clk_disable_unprepare(dw_wdt.clk);
+ clk_disable_unprepare(wdev->clk);
return 0;
}
