On Tue, Sep 23, 2014 at 03:42:12PM +0800, Jisheng Zhang wrote:
> The kernel core now provides an API to trigger a system restart.
> Register with it to support restarting the system via. watchdog.
>
> Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxxx>
> ---
> drivers/watchdog/dw_wdt.c | 32 ++++++++++++++++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
> index 449c885..9e577a6 100644
> --- a/drivers/watchdog/dw_wdt.c
> +++ b/drivers/watchdog/dw_wdt.c
> @@ -21,6 +21,7 @@
>
> #include <linux/bitops.h>
> #include <linux/clk.h>
> +#include <linux/delay.h>
> #include <linux/device.h>
> #include <linux/err.h>
> #include <linux/fs.h>
> @@ -29,9 +30,11 @@
> #include <linux/miscdevice.h>
> #include <linux/module.h>
> #include <linux/moduleparam.h>
> +#include <linux/notifier.h>
> #include <linux/of.h>
> #include <linux/pm.h>
> #include <linux/platform_device.h>
> +#include <linux/reboot.h>
> #include <linux/spinlock.h>
> #include <linux/timer.h>
> #include <linux/uaccess.h>
> @@ -63,6 +66,7 @@ static struct {
> unsigned long next_heartbeat;
> struct timer_list timer;
> int expect_close;
> + struct notifier_block restart_handler;
> } dw_wdt;
>
> static inline int dw_wdt_is_enabled(void)
> @@ -121,6 +125,26 @@ static void dw_wdt_keepalive(void)
> WDOG_COUNTER_RESTART_REG_OFFSET);
> }
>
> +static int dw_wdt_restart_handle(struct notifier_block *this,
> + unsigned long mode, void *cmd)
> +{
> + u32 val;
> +
> + writel(0, dw_wdt.regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
> + val = readl(dw_wdt.regs + WDOG_CONTROL_REG_OFFSET);
> + if (val & WDOG_CONTROL_REG_WDT_EN_MASK)
> + writel(WDOG_COUNTER_RESTART_KICK_VALUE, dw_wdt.regs +
> + WDOG_COUNTER_RESTART_REG_OFFSET);
> + else
> + writel(WDOG_CONTROL_REG_WDT_EN_MASK,
> + dw_wdt.regs + WDOG_CONTROL_REG_OFFSET);
> +
> + /* wait for reset to assert... */
> + mdelay(500);
> +
> + return NOTIFY_DONE;
> +}
> +
> static void dw_wdt_ping(unsigned long data)
> {
> if (time_before(jiffies, dw_wdt.next_heartbeat) ||
> @@ -316,6 +340,12 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
> if (ret)
> goto out_disable_clk;
>
> + dw_wdt.restart_handler.notifier_call = dw_wdt_restart_handle;
> + dw_wdt.restart_handler.priority = 128;
> + ret = register_restart_handler(&dw_wdt.restart_handler);
> + if (ret)
> + pr_warn("cannot register restart handler\n");
Please use dev_warn(&pdev->dev, ...).
Thanks,
Guenter
> +
> dw_wdt_set_next_heartbeat();
> setup_timer(&dw_wdt.timer, dw_wdt_ping, 0);
> mod_timer(&dw_wdt.timer, jiffies + WDT_TIMEOUT);
> @@ -330,6 +360,8 @@ out_disable_clk:
>
> static int dw_wdt_drv_remove(struct platform_device *pdev)
> {
> + unregister_restart_handler(&dw_wdt.restart_handler);
> +
> misc_deregister(&dw_wdt_miscdev);
>
> clk_disable_unprepare(dw_wdt.clk);
> --
> 2.1.0
>
> --
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