watchdog: sama5d4_wdt: Fix WDDIS detection on SAM9X60 and SAMA7G5

The driver hardcoded AT91_WDT_WDDIS (bit 15) in wdt_enabled and the
probe initial state readout. SAM9X60 and SAMA7G5 use bit 12
(AT91_SAM9X60_WDDIS), causing incorrect WDDIS detection.

Introduce a per-device wddis_mask field to select the correct WDDIS
bit based on the compatible string.

Fixes: 266da53c35fc ("watchdog: sama5d4: readout initial state")
Co-developed-by: Andrei Simion <andrei.simion@microchip.com>
Signed-off-by: Andrei Simion <andrei.simion@microchip.com>
Signed-off-by: Balakrishnan Sambath <balakrishnan.s@microchip.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20260302113310.133989-2-balakrishnan.s@microchip.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 21 insertions, 27 deletions

diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c
index 13e72918338a..704b786cc2ec 100644
--- a/drivers/watchdog/sama5d4_wdt.c
+++ b/drivers/watchdog/sama5d4_wdt.c
@@ -30,6 +30,7 @@ struct sama5d4_wdt {
 	void __iomem		*reg_base;
 	u32			mr;
 	u32			ir;
+	u32			wddis_mask;
 	unsigned long		last_ping;
 	bool			need_irq;
 	bool			sam9x60_support;
@@ -48,7 +49,10 @@ MODULE_PARM_DESC(nowayout,
 	"Watchdog cannot be stopped once started (default="
 	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 
-#define wdt_enabled (!(wdt->mr & AT91_WDT_WDDIS))
+static inline bool wdt_enabled(struct sama5d4_wdt *wdt)
+{
+	return !(wdt->mr & wdt->wddis_mask);
+}
 
 #define wdt_read(wdt, field) \
 	readl_relaxed((wdt)->reg_base + (field))
@@ -81,12 +85,9 @@ static int sama5d4_wdt_start(struct watchdog_device *wdd)
 {
 	struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
 
-	if (wdt->sam9x60_support) {
+	if (wdt->sam9x60_support)
 		writel_relaxed(wdt->ir, wdt->reg_base + AT91_SAM9X60_IER);
-		wdt->mr &= ~AT91_SAM9X60_WDDIS;
-	} else {
-		wdt->mr &= ~AT91_WDT_WDDIS;
-	}
+	wdt->mr &= ~wdt->wddis_mask;
 	wdt_write(wdt, AT91_WDT_MR, wdt->mr);
 
 	return 0;
@@ -96,12 +97,9 @@ static int sama5d4_wdt_stop(struct watchdog_device *wdd)
 {
 	struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
 
-	if (wdt->sam9x60_support) {
+	if (wdt->sam9x60_support)
 		writel_relaxed(wdt->ir, wdt->reg_base + AT91_SAM9X60_IDR);
-		wdt->mr |= AT91_SAM9X60_WDDIS;
-	} else {
-		wdt->mr |= AT91_WDT_WDDIS;
-	}
+	wdt->mr |= wdt->wddis_mask;
 	wdt_write(wdt, AT91_WDT_MR, wdt->mr);
 
 	return 0;
@@ -117,7 +115,7 @@ static int sama5d4_wdt_ping(struct watchdog_device *wdd)
 }
 
 static int sama5d4_wdt_set_timeout(struct watchdog_device *wdd,
-				 unsigned int timeout)
+				    unsigned int timeout)
 {
 	struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
 	u32 value = WDT_SEC2TICKS(timeout);
@@ -140,8 +138,8 @@ static int sama5d4_wdt_set_timeout(struct watchdog_device *wdd,
 	 * If the watchdog is enabled, then the timeout can be updated. Else,
 	 * wait that the user enables it.
 	 */
-	if (wdt_enabled)
-		wdt_write(wdt, AT91_WDT_MR, wdt->mr & ~AT91_WDT_WDDIS);
+	if (wdt_enabled(wdt))
+		wdt_write(wdt, AT91_WDT_MR, wdt->mr & ~wdt->wddis_mask);
 
 	wdd->timeout = timeout;
 
@@ -184,10 +182,7 @@ static int of_sama5d4_wdt_init(struct device_node *np, struct sama5d4_wdt *wdt)
 {
 	const char *tmp;
 
-	if (wdt->sam9x60_support)
-		wdt->mr = AT91_SAM9X60_WDDIS;
-	else
-		wdt->mr = AT91_WDT_WDDIS;
+	wdt->mr = wdt->wddis_mask;
 
 	if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) &&
 	    !strcmp(tmp, "software"))
@@ -213,15 +208,11 @@ static int sama5d4_wdt_init(struct sama5d4_wdt *wdt)
 	 * If the watchdog is already running, we can safely update it.
 	 * Else, we have to disable it properly.
 	 */
-	if (!wdt_enabled) {
+	if (!wdt_enabled(wdt)) {
 		reg = wdt_read(wdt, AT91_WDT_MR);
-		if (wdt->sam9x60_support && (!(reg & AT91_SAM9X60_WDDIS)))
-			wdt_write_nosleep(wdt, AT91_WDT_MR,
-					  reg | AT91_SAM9X60_WDDIS);
-		else if (!wdt->sam9x60_support &&
-			 (!(reg & AT91_WDT_WDDIS)))
+		if (!(reg & wdt->wddis_mask))
 			wdt_write_nosleep(wdt, AT91_WDT_MR,
-					  reg | AT91_WDT_WDDIS);
+					  reg | wdt->wddis_mask);
 	}
 
 	if (wdt->sam9x60_support) {
@@ -273,6 +264,9 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
 	    of_device_is_compatible(dev->of_node, "microchip,sama7g5-wdt"))
 		wdt->sam9x60_support = true;
 
+	wdt->wddis_mask = wdt->sam9x60_support ? AT91_SAM9X60_WDDIS
+						: AT91_WDT_WDDIS;
+
 	watchdog_set_drvdata(wdd, wdt);
 
 	regs = devm_platform_ioremap_resource(pdev, 0);
@@ -306,8 +300,8 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
 	watchdog_init_timeout(wdd, wdt_timeout, dev);
 
 	reg = wdt_read(wdt, AT91_WDT_MR);
-	if (!(reg & AT91_WDT_WDDIS)) {
-		wdt->mr &= ~AT91_WDT_WDDIS;
+	if (!(reg & wdt->wddis_mask)) {
+		wdt->mr &= ~wdt->wddis_mask;
 		set_bit(WDOG_HW_RUNNING, &wdd->status);
 	}