On Mon, Dec 11, 2017 at 11:21:08AM -0600, David Lechner wrote:
> This adds a restart function to the davinci watchdog timer driver.
> 
> This is copied from arch/arm/mach-davinci/time.c and will allow us to
> remove the code from there.
> 
> Signed-off-by: David Lechner <[email protected]>

Reviewed-by: Guenter Roeck <[email protected]>

> ---
>  drivers/watchdog/davinci_wdt.c | 38 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 38 insertions(+)
> 
> diff --git a/drivers/watchdog/davinci_wdt.c b/drivers/watchdog/davinci_wdt.c
> index 2f46487..3e4c592 100644
> --- a/drivers/watchdog/davinci_wdt.c
> +++ b/drivers/watchdog/davinci_wdt.c
> @@ -140,6 +140,42 @@ static unsigned int davinci_wdt_get_timeleft(struct 
> watchdog_device *wdd)
>       return wdd->timeout - timer_counter;
>  }
>  
> +static int davinci_wdt_restart(struct watchdog_device *wdd,
> +                            unsigned long action, void *data)
> +{
> +     struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
> +     u32 tgcr, wdtcr;
> +
> +     /* disable, internal clock source */
> +     iowrite32(0, davinci_wdt->base + TCR);
> +
> +     /* reset timer, set mode to 64-bit watchdog, and unreset */
> +     tgcr = 0;
> +     iowrite32(tgcr, davinci_wdt->base + TGCR);
> +     tgcr = TIMMODE_64BIT_WDOG | TIM12RS_UNRESET | TIM34RS_UNRESET;
> +     iowrite32(tgcr, davinci_wdt->base + TGCR);
> +
> +     /* clear counter and period regs */
> +     iowrite32(0, davinci_wdt->base + TIM12);
> +     iowrite32(0, davinci_wdt->base + TIM34);
> +     iowrite32(0, davinci_wdt->base + PRD12);
> +     iowrite32(0, davinci_wdt->base + PRD34);
> +
> +     /* put watchdog in pre-active state */
> +     wdtcr = WDKEY_SEQ0 | WDEN;
> +     iowrite32(wdtcr, davinci_wdt->base + WDTCR);
> +
> +     /* put watchdog in active state */
> +     wdtcr = WDKEY_SEQ1 | WDEN;
> +     iowrite32(wdtcr, davinci_wdt->base + WDTCR);
> +
> +     /* write an invalid value to the WDKEY field to trigger a restart */
> +     wdtcr = 0x00004000;
> +     iowrite32(wdtcr, davinci_wdt->base + WDTCR);
> +
> +     return 0;
> +}
> +
>  static const struct watchdog_info davinci_wdt_info = {
>       .options = WDIOF_KEEPALIVEPING,
>       .identity = "DaVinci/Keystone Watchdog",
> @@ -151,6 +187,7 @@ static const struct watchdog_ops davinci_wdt_ops = {
>       .stop           = davinci_wdt_ping,
>       .ping           = davinci_wdt_ping,
>       .get_timeleft   = davinci_wdt_get_timeleft,
> +     .restart        = davinci_wdt_restart,
>  };
>  
>  static int davinci_wdt_probe(struct platform_device *pdev)
> @@ -195,6 +232,7 @@ static int davinci_wdt_probe(struct platform_device *pdev)
>  
>       watchdog_set_drvdata(wdd, davinci_wdt);
>       watchdog_set_nowayout(wdd, 1);
> +     watchdog_set_restart_priority(wdd, 128);
>  
>       wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>       davinci_wdt->base = devm_ioremap_resource(dev, wdt_mem);
> -- 
> 2.7.4
> 

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