[PATCH v2 6/8] watchdog: at91sam9_wdt: Add SAM9X60 support

[Eugen Hristev]

On 4/17/25 12:09, Zixun LI wrote:
> SAM9X60 has a slightly different watchdog implementation:
> - Timer value moved into a new register WLR
> - Some MR register fields have their position changed

I would add the support for sam9x60 as a single patch, this one and
previous (patch 5) which adds the registers definition.
I don't see a reason for a patch to add unused register definitions and
then create another patch that uses them.

> 
> This patch add SAM9X60 support, also adds a compatible
> for SAMA5D4 who is the same as existing SAM9260.
> 
> Signed-off-by: Zixun LI <admin at hifiphile.com>
> ---
>  arch/arm/mach-at91/include/mach/at91_wdt.h |  7 ++++++
>  drivers/watchdog/at91sam9_wdt.c            | 39 ++++++++++++++++++++++++------
>  2 files changed, 38 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/arm/mach-at91/include/mach/at91_wdt.h b/arch/arm/mach-at91/include/mach/at91_wdt.h
> index 9ba5283123bcf637bb1c3c66f7b98104e232ae05..9a3976d9e970c212d348daeabc14c2fd6c54a8b5 100644
> --- a/arch/arm/mach-at91/include/mach/at91_wdt.h
> +++ b/arch/arm/mach-at91/include/mach/at91_wdt.h
> @@ -19,9 +19,16 @@
>  
>  #else
>  
> +enum {
> +	AT91_WDT_MODE_SAM9260 = 0,
> +	AT91_WDT_MODE_SAM9X60 = 1
> +};
> +
>  struct at91_wdt_priv {
>  	void __iomem *regs;
>  	u32 mr;
> +	u32 wddis;
> +	u8 mode;
>  };
>  
>  #endif
> diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c
> index 5ca3e5a5fdefb3101c97754f10b65c0acd69a522..72e13787448e366036dce4a451cc2294e5b60a0d 100644
> --- a/drivers/watchdog/at91sam9_wdt.c
> +++ b/drivers/watchdog/at91sam9_wdt.c
> @@ -49,7 +49,7 @@ static int at91_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
>  	ticks = WDT_SEC2TICKS(timeout);
>  
>  	/* Check if disabled */
> -	if (readl(wdt->regs + AT91_WDT_MR) & AT91_WDT_MR_WDDIS) {
> +	if (readl(wdt->regs + AT91_WDT_MR) & wdt->wddis) {
>  		printf("sorry, watchdog is disabled\n");
>  		return -1;
>  	}
> @@ -60,11 +60,21 @@ static int at91_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
>  	 * Since WDV is a 12-bit counter, the maximum period is
>  	 * 4096 / 256 = 16 seconds.
>  	 */
> -	wdt->mr = AT91_WDT_MR_WDRSTEN	/* causes watchdog reset */
> -		| AT91_WDT_MR_WDDBGHLT		/* disabled in debug mode */
> -		| AT91_WDT_MR_WDD(0xfff)	/* restart at any time */
> -		| AT91_WDT_MR_WDV(ticks);	/* timer value */
> -	writel(wdt->mr, wdt->regs + AT91_WDT_MR);
> +
> +	if (wdt->mode == AT91_WDT_MODE_SAM9260) {
> +		wdt->mr = AT91_WDT_MR_WDRSTEN	/* causes watchdog reset */
> +		    | AT91_WDT_MR_WDDBGHLT	/* disabled in debug mode */
> +		    | AT91_WDT_MR_WDD(0xfff)	/* restart at any time */
> +		    | AT91_WDT_MR_WDV(ticks);	/* timer value */
> +		writel(wdt->mr, wdt->regs + AT91_WDT_MR);
> +	} else if (wdt->mode == AT91_WDT_MODE_SAM9X60) {
> +		writel(AT91_SAM9X60_WLR_COUNTER(ticks),	/* timer value */
> +		       wdt->regs + AT91_SAM9X60_WLR);
> +
> +		wdt->mr = AT91_SAM9X60_MR_PERIODRST /* causes watchdog reset */
> +			| AT91_SAM9X60_MR_WDDBGHLT; /* disabled in debug mode */
> +		writel(wdt->mr, wdt->regs + AT91_WDT_MR);
> +	}
>  
>  	return 0;
>  }
> @@ -74,7 +84,7 @@ static int at91_wdt_stop(struct udevice *dev)
>  	struct at91_wdt_priv *wdt = dev_get_priv(dev);
>  
>  	/* Disable Watchdog Timer */
> -	wdt->mr |= AT91_WDT_MR_WDDIS;
> +	wdt->mr |= wdt->wddis;
>  	writel(wdt->mr, wdt->regs + AT91_WDT_MR);
>  
>  	return 0;
> @@ -96,7 +106,14 @@ static const struct wdt_ops at91_wdt_ops = {
>  };
>  
>  static const struct udevice_id at91_wdt_ids[] = {
> -	{ .compatible = "atmel,at91sam9260-wdt" },
> +	{ .compatible = "atmel,at91sam9260-wdt",
> +	  .data = AT91_WDT_MODE_SAM9260 },
> +	{ .compatible = "atmel,sama5d4-wdt",
> +	  .data = AT91_WDT_MODE_SAM9260 },
> +	{ .compatible = "microchip,sam9x60-wdt",
> +	  .data = AT91_WDT_MODE_SAM9X60 },
> +	{ .compatible = "microchip,sama7g5-wdt",
> +	  .data = AT91_WDT_MODE_SAM9X60 },
>  	{}
>  };
>  
> @@ -108,6 +125,12 @@ static int at91_wdt_probe(struct udevice *dev)
>  	if (!wdt->regs)
>  		return -EINVAL;
>  
> +	wdt->mode = dev_get_driver_data(dev);
> +	if (wdt->mode == AT91_WDT_MODE_SAM9260)
> +		wdt->wddis = AT91_WDT_MR_WDDIS;
> +	else if (wdt->mode == AT91_WDT_MODE_SAM9X60)
> +		wdt->wddis = AT91_SAM9X60_MR_WDDIS;
> +
>  	debug("%s: Probing wdt%u\n", __func__, dev_seq(dev));
>  
>  	return 0;
>