[PATCH v4 0/2] Add reaction control in rti

[PATCH v4 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 the reset output 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 v3:
- Expected default reaction for watchdog is HW reset line, so check for NMI
  and set reaction to NMI if exists, else default to HW reset.

v3: https://lore.kernel.org/linux-devicetree/20250707180002.3918865-1-jm@ti.com/
v2: https://lore.kernel.org/linux-devicetree/20250625143338.2381726-1-jm@ti.com/
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                    | 32 ++++++++++++++++---
 2 files changed, 29 insertions(+), 4 deletions(-)

-- 
2.49.0

[PATCH v4 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>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 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 v4 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>
---
 drivers/watchdog/rti_wdt.c | 32 ++++++++++++++++++++++++++++----
 1 file changed, 28 insertions(+), 4 deletions(-)

diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
index d1f9ce4100a8..0c01e7e46100 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 nmi;
+};
+
 /*
  * 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 +109,13 @@ 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);
+	/* Reset device if wdt serviced outside of window or generate NMI if available */
+	if (wdt->data->nmi)
+		reaction = RTIWWDRXN_NMI;
+	else
+		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 +268,8 @@ static int rti_wdt_probe(struct platform_device *pdev)
 	wdd->timeout = DEFAULT_HEARTBEAT;
 	wdd->parent = dev;
 
+	wdt->data = device_get_match_data(dev);
+
 	watchdog_set_drvdata(wdd, wdt);
 	watchdog_set_nowayout(wdd, 1);
 	watchdog_set_restart_priority(wdd, 128);
@@ -369,8 +384,17 @@ static void rti_wdt_remove(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 }
 
+static struct rti_wdt_data j7_wdt = {
+	.nmi = true,
+};
+
+static struct rti_wdt_data am62l_wdt = {
+	.nmi = false,
+};
+
 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