[PATCH v2 0/2] Add reaction control in rti

[PATCH v2 0/2] Add reaction control in rti

[Judith Mendez]

This allows for reaction control in rti driver. Since AM62L SoC [0]
does not have WWD reset output routed to a ESM module like all other
K3 SoC's and has a reset signal routed to the reset HW block, add a new
compatible for AM62L and configure reset reaction for AM62L SoC instead
of NMI.

This patch has been tested on AM62L EVM [1].

Changes since v1-resend:
- Binding: order compatible alphabetically

v1-resend: https://lore.kernel.org/linux-devicetree/20250624202605.1333645-1-jm@ti.com/
v1: https://lore.kernel.org/linux-devicetree/20250624194509.1314095-1-jm@ti.com/

[0] https://www.ti.com/product/AM62L
[1] https://www.ti.com/tool/TMDS62LEVM

Judith Mendez (2):
  dt-bindings: watchdog: ti,rti-wdt: Add ti,am62l-rti-wdt compatible
  watchdog: rti_wdt: Add reaction control

 .../bindings/watchdog/ti,rti-wdt.yaml         |  1 +
 drivers/watchdog/rti_wdt.c                    | 31 ++++++++++++++++---
 2 files changed, 28 insertions(+), 4 deletions(-)

-- 
2.49.0

[PATCH v2 1/2] dt-bindings: watchdog: ti,rti-wdt: Add ti,am62l-rti-wdt compatible

[Judith Mendez]

Add a new compatible ti,am62l-rti-wdt for am62l SoC [0].

[0] https://www.ti.com/product/AM62L
Signed-off-by: Judith Mendez <jm@ti.com>
---
Changes since v1-resend:
- Binding: order compatible alphabetically
---
 Documentation/devicetree/bindings/watchdog/ti,rti-wdt.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/watchdog/ti,rti-wdt.yaml b/Documentation/devicetree/bindings/watchdog/ti,rti-wdt.yaml
index 62ddc284a524..2966e5bfb6c0 100644
--- a/Documentation/devicetree/bindings/watchdog/ti,rti-wdt.yaml
+++ b/Documentation/devicetree/bindings/watchdog/ti,rti-wdt.yaml
@@ -23,6 +23,7 @@ allOf:
 properties:
   compatible:
     enum:
+      - ti,am62l-rti-wdt
       - ti,j7-rti-wdt
 
   reg:
-- 
2.49.0

[PATCH v2 2/2] watchdog: rti_wdt: Add reaction control

[Judith Mendez]

This allows to configure reaction between NMI and reset for WWD.

On K3 SoC's other than AM62L SoC [0], watchdog reset output is routed
to the ESM module which can subsequently route the signal to safety
master or SoC reset. On AM62L, the watchdog reset output is routed
to the SoC HW reset block. So, add a new compatible for AM62l to add
SoC data and configure reaction to reset instead of NMI.

[0] https://www.ti.com/product/AM62L
Signed-off-by: Judith Mendez <jm@ti.com>
---
Changes since v1-resend:
- no change
---
 drivers/watchdog/rti_wdt.c | 31 +++++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
index d1f9ce4100a8..d419884c86c4 100644
--- a/drivers/watchdog/rti_wdt.c
+++ b/drivers/watchdog/rti_wdt.c
@@ -35,7 +35,8 @@
 #define RTIWWDRXCTRL	0xa4
 #define RTIWWDSIZECTRL	0xa8
 
-#define RTIWWDRX_NMI	0xa
+#define RTIWWDRXN_RST	0x5
+#define RTIWWDRXN_NMI	0xa
 
 #define RTIWWDSIZE_50P		0x50
 #define RTIWWDSIZE_25P		0x500
@@ -63,22 +64,29 @@
 
 static int heartbeat;
 
+struct rti_wdt_data {
+	bool reset;
+};
+
 /*
  * struct to hold data for each WDT device
  * @base - base io address of WD device
  * @freq - source clock frequency of WDT
  * @wdd  - hold watchdog device as is in WDT core
+ * @data - hold configuration data
  */
 struct rti_wdt_device {
 	void __iomem		*base;
 	unsigned long		freq;
 	struct watchdog_device	wdd;
+	const struct rti_wdt_data *data;
 };
 
 static int rti_wdt_start(struct watchdog_device *wdd)
 {
 	u32 timer_margin;
 	struct rti_wdt_device *wdt = watchdog_get_drvdata(wdd);
+	u8 reaction;
 	int ret;
 
 	ret = pm_runtime_resume_and_get(wdd->parent);
@@ -101,8 +109,12 @@ static int rti_wdt_start(struct watchdog_device *wdd)
 	 */
 	wdd->min_hw_heartbeat_ms = 520 * wdd->timeout + MAX_HW_ERROR;
 
-	/* Generate NMI when wdt expires */
-	writel_relaxed(RTIWWDRX_NMI, wdt->base + RTIWWDRXCTRL);
+	/* Generate reset or NMI when timer expires/serviced outside of window */
+	reaction = RTIWWDRXN_NMI;
+	if (wdt->data->reset)
+		reaction = RTIWWDRXN_RST;
+
+	writel_relaxed(reaction, wdt->base + RTIWWDRXCTRL);
 
 	/* Open window size 50%; this is the largest window size available */
 	writel_relaxed(RTIWWDSIZE_50P, wdt->base + RTIWWDSIZECTRL);
@@ -255,6 +267,8 @@ static int rti_wdt_probe(struct platform_device *pdev)
 	wdd->timeout = DEFAULT_HEARTBEAT;
 	wdd->parent = dev;
 
+	wdt->data = of_device_get_match_data(dev);
+
 	watchdog_set_drvdata(wdd, wdt);
 	watchdog_set_nowayout(wdd, 1);
 	watchdog_set_restart_priority(wdd, 128);
@@ -369,8 +383,17 @@ static void rti_wdt_remove(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 }
 
+static struct rti_wdt_data j7_wdt = {
+	.reset = false,
+};
+
+static struct rti_wdt_data am62l_wdt = {
+	.reset = true,
+};
+
 static const struct of_device_id rti_wdt_of_match[] = {
-	{ .compatible = "ti,j7-rti-wdt", },
+	{ .compatible = "ti,j7-rti-wdt", .data = &j7_wdt },
+	{ .compatible = "ti,am62l-rti-wdt", .data = &am62l_wdt },
 	{},
 };
 MODULE_DEVICE_TABLE(of, rti_wdt_of_match);
-- 
2.49.0

Re: [PATCH v2 1/2] dt-bindings: watchdog: ti,rti-wdt: Add ti,am62l-rti-wdt compatible

[Krzysztof Kozlowski]

On Wed, Jun 25, 2025 at 09:33:37AM -0500, Judith Mendez wrote:
> Add a new compatible ti,am62l-rti-wdt for am62l SoC [0].
> 
> [0] https://www.ti.com/product/AM62L
> Signed-off-by: Judith Mendez <jm@ti.com>
> ---
> Changes since v1-resend:
> - Binding: order compatible alphabetically

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

Re: [PATCH v2 2/2] watchdog: rti_wdt: Add reaction control

[Andrew Davis]

On 6/25/25 9:33 AM, Judith Mendez wrote:
> This allows to configure reaction between NMI and reset for WWD.
> 
> On K3 SoC's other than AM62L SoC [0], watchdog reset output is routed
> to the ESM module which can subsequently route the signal to safety
> master or SoC reset. On AM62L, the watchdog reset output is routed
> to the SoC HW reset block. So, add a new compatible for AM62l to add
> SoC data and configure reaction to reset instead of NMI.

Should this be something we configure, not selected based on device,
do we know if all user of AM62L want the device reset on WDT?

> 
> [0] https://www.ti.com/product/AM62L
> Signed-off-by: Judith Mendez <jm@ti.com>
> ---
> Changes since v1-resend:
> - no change
> ---
>   drivers/watchdog/rti_wdt.c | 31 +++++++++++++++++++++++++++----
>   1 file changed, 27 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
> index d1f9ce4100a8..d419884c86c4 100644
> --- a/drivers/watchdog/rti_wdt.c
> +++ b/drivers/watchdog/rti_wdt.c
> @@ -35,7 +35,8 @@
>   #define RTIWWDRXCTRL	0xa4
>   #define RTIWWDSIZECTRL	0xa8
>   
> -#define RTIWWDRX_NMI	0xa
> +#define RTIWWDRXN_RST	0x5
> +#define RTIWWDRXN_NMI	0xa
>   
>   #define RTIWWDSIZE_50P		0x50
>   #define RTIWWDSIZE_25P		0x500
> @@ -63,22 +64,29 @@
>   
>   static int heartbeat;
>   
> +struct rti_wdt_data {
> +	bool reset;
> +};
> +
>   /*
>    * struct to hold data for each WDT device
>    * @base - base io address of WD device
>    * @freq - source clock frequency of WDT
>    * @wdd  - hold watchdog device as is in WDT core
> + * @data - hold configuration data
>    */
>   struct rti_wdt_device {
>   	void __iomem		*base;
>   	unsigned long		freq;
>   	struct watchdog_device	wdd;
> +	const struct rti_wdt_data *data;
>   };
>   
>   static int rti_wdt_start(struct watchdog_device *wdd)
>   {
>   	u32 timer_margin;
>   	struct rti_wdt_device *wdt = watchdog_get_drvdata(wdd);
> +	u8 reaction;
>   	int ret;
>   
>   	ret = pm_runtime_resume_and_get(wdd->parent);
> @@ -101,8 +109,12 @@ static int rti_wdt_start(struct watchdog_device *wdd)
>   	 */
>   	wdd->min_hw_heartbeat_ms = 520 * wdd->timeout + MAX_HW_ERROR;
>   
> -	/* Generate NMI when wdt expires */
> -	writel_relaxed(RTIWWDRX_NMI, wdt->base + RTIWWDRXCTRL);
> +	/* Generate reset or NMI when timer expires/serviced outside of window */
> +	reaction = RTIWWDRXN_NMI;
> +	if (wdt->data->reset)
> +		reaction = RTIWWDRXN_RST;
> +

Suggest:

/* Reset device if wdt serviced outside of window or generate NMI if available */
if (wdt->data->reset)
	reaction = RTIWWDRXN_RST;
else
	reaction = RTIWWDRXN_NMI;

> +	writel_relaxed(reaction, wdt->base + RTIWWDRXCTRL);
>   
>   	/* Open window size 50%; this is the largest window size available */
>   	writel_relaxed(RTIWWDSIZE_50P, wdt->base + RTIWWDSIZECTRL);
> @@ -255,6 +267,8 @@ static int rti_wdt_probe(struct platform_device *pdev)
>   	wdd->timeout = DEFAULT_HEARTBEAT;
>   	wdd->parent = dev;
>   
> +	wdt->data = of_device_get_match_data(dev);

You can use device_get_match_data() here.

Andrew

> +
>   	watchdog_set_drvdata(wdd, wdt);
>   	watchdog_set_nowayout(wdd, 1);
>   	watchdog_set_restart_priority(wdd, 128);
> @@ -369,8 +383,17 @@ static void rti_wdt_remove(struct platform_device *pdev)
>   	pm_runtime_disable(&pdev->dev);
>   }
>   
> +static struct rti_wdt_data j7_wdt = {
> +	.reset = false,
> +};
> +
> +static struct rti_wdt_data am62l_wdt = {
> +	.reset = true,
> +};
> +
>   static const struct of_device_id rti_wdt_of_match[] = {
> -	{ .compatible = "ti,j7-rti-wdt", },
> +	{ .compatible = "ti,j7-rti-wdt", .data = &j7_wdt },
> +	{ .compatible = "ti,am62l-rti-wdt", .data = &am62l_wdt },
>   	{},
>   };
>   MODULE_DEVICE_TABLE(of, rti_wdt_of_match);

Re: [PATCH v2 2/2] watchdog: rti_wdt: Add reaction control

[Judith Mendez]

On 6/27/25 1:31 PM, Andrew Davis wrote:
> On 6/25/25 9:33 AM, Judith Mendez wrote:
>> This allows to configure reaction between NMI and reset for WWD.
>>
>> On K3 SoC's other than AM62L SoC [0], watchdog reset output is routed
>> to the ESM module which can subsequently route the signal to safety
>> master or SoC reset. On AM62L, the watchdog reset output is routed
>> to the SoC HW reset block. So, add a new compatible for AM62l to add
>> SoC data and configure reaction to reset instead of NMI.
> 
> Should this be something we configure, not selected based on device,
> do we know if all user of AM62L want the device reset on WDT?

I will assume that end user will want watchdog to actually reset
the system if watchdog is enabled.

If they don't use watchdog, they wont care. I believe it should be per
device/SoC.

> 
>>
>> [0] https://www.ti.com/product/AM62L
>> Signed-off-by: Judith Mendez <jm@ti.com>
>> ---
>> Changes since v1-resend:
>> - no change
>> ---
>>   drivers/watchdog/rti_wdt.c | 31 +++++++++++++++++++++++++++----
>>   1 file changed, 27 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
>> index d1f9ce4100a8..d419884c86c4 100644
>> --- a/drivers/watchdog/rti_wdt.c
>> +++ b/drivers/watchdog/rti_wdt.c
>> @@ -35,7 +35,8 @@
>>   #define RTIWWDRXCTRL    0xa4
>>   #define RTIWWDSIZECTRL    0xa8
>> -#define RTIWWDRX_NMI    0xa
>> +#define RTIWWDRXN_RST    0x5
>> +#define RTIWWDRXN_NMI    0xa
>>   #define RTIWWDSIZE_50P        0x50
>>   #define RTIWWDSIZE_25P        0x500
>> @@ -63,22 +64,29 @@
>>   static int heartbeat;
>> +struct rti_wdt_data {
>> +    bool reset;
>> +};
>> +
>>   /*
>>    * struct to hold data for each WDT device
>>    * @base - base io address of WD device
>>    * @freq - source clock frequency of WDT
>>    * @wdd  - hold watchdog device as is in WDT core
>> + * @data - hold configuration data
>>    */
>>   struct rti_wdt_device {
>>       void __iomem        *base;
>>       unsigned long        freq;
>>       struct watchdog_device    wdd;
>> +    const struct rti_wdt_data *data;
>>   };
>>   static int rti_wdt_start(struct watchdog_device *wdd)
>>   {
>>       u32 timer_margin;
>>       struct rti_wdt_device *wdt = watchdog_get_drvdata(wdd);
>> +    u8 reaction;
>>       int ret;
>>       ret = pm_runtime_resume_and_get(wdd->parent);
>> @@ -101,8 +109,12 @@ static int rti_wdt_start(struct watchdog_device 
>> *wdd)
>>        */
>>       wdd->min_hw_heartbeat_ms = 520 * wdd->timeout + MAX_HW_ERROR;
>> -    /* Generate NMI when wdt expires */
>> -    writel_relaxed(RTIWWDRX_NMI, wdt->base + RTIWWDRXCTRL);
>> +    /* Generate reset or NMI when timer expires/serviced outside of 
>> window */
>> +    reaction = RTIWWDRXN_NMI;
>> +    if (wdt->data->reset)
>> +        reaction = RTIWWDRXN_RST;
>> +
> 
> Suggest:
> 
> /* Reset device if wdt serviced outside of window or generate NMI if 
> available */
> if (wdt->data->reset)
>      reaction = RTIWWDRXN_RST;
> else
>      reaction = RTIWWDRXN_NMI;

Sure, will fix for v3

> 
>> +    writel_relaxed(reaction, wdt->base + RTIWWDRXCTRL);
>>       /* Open window size 50%; this is the largest window size 
>> available */
>>       writel_relaxed(RTIWWDSIZE_50P, wdt->base + RTIWWDSIZECTRL);
>> @@ -255,6 +267,8 @@ static int rti_wdt_probe(struct platform_device 
>> *pdev)
>>       wdd->timeout = DEFAULT_HEARTBEAT;
>>       wdd->parent = dev;
>> +    wdt->data = of_device_get_match_data(dev);
> 
> You can use device_get_match_data() here.
> 
Sure, will fix for v3

> Andrew
> 
>> +
>>       watchdog_set_drvdata(wdd, wdt);
>>       watchdog_set_nowayout(wdd, 1);
>>       watchdog_set_restart_priority(wdd, 128);
>> @@ -369,8 +383,17 @@ static void rti_wdt_remove(struct platform_device 
>> *pdev)
>>       pm_runtime_disable(&pdev->dev);
>>   }
>> +static struct rti_wdt_data j7_wdt = {
>> +    .reset = false,
>> +};
>> +
>> +static struct rti_wdt_data am62l_wdt = {
>> +    .reset = true,
>> +};
>> +
>>   static const struct of_device_id rti_wdt_of_match[] = {
>> -    { .compatible = "ti,j7-rti-wdt", },
>> +    { .compatible = "ti,j7-rti-wdt", .data = &j7_wdt },
>> +    { .compatible = "ti,am62l-rti-wdt", .data = &am62l_wdt },
>>       {},
>>   };
>>   MODULE_DEVICE_TABLE(of, rti_wdt_of_match);