[PATCH v2] drivers: watchdog: ast2600 support bootstatus

[Peter Yin]

Add WDIOF_EXTERN1 and WDIOF_CARDRESET bootstatus in ast2600

Regarding the AST2600 specification, the WDTn Timeout Status Register
(WDT10) has bit 1 reserved. To verify the second boot source,
we need to check SEC14 bit 12 and bit 13.
The bits 8-23 in the WDTn Timeout Status Register are the Watchdog
Event Count, which we can use to verify WDIOF_EXTERN1.

Signed-off-by: Peter Yin <peteryin.openbmc at gmail.com>
---
Change log:

v1 -> v2
  - Add comment and support WDIOF_CARDRESET in ast2600

v1
  - Patch 0001 - Add WDIOF_EXTERN1 bootstatus
---
 arch/arm/boot/dts/aspeed/aspeed-g6.dtsi |  8 ++---
 drivers/watchdog/aspeed_wdt.c           | 45 ++++++++++++++++++++++---
 2 files changed, 44 insertions(+), 9 deletions(-)

diff --git a/arch/arm/boot/dts/aspeed/aspeed-g6.dtsi b/arch/arm/boot/dts/aspeed/aspeed-g6.dtsi
index e0b44498269f..23ae7f0430e9 100644
--- a/arch/arm/boot/dts/aspeed/aspeed-g6.dtsi
+++ b/arch/arm/boot/dts/aspeed/aspeed-g6.dtsi
@@ -556,24 +556,24 @@ uart5: serial at 1e784000 {
 
 			wdt1: watchdog at 1e785000 {
 				compatible = "aspeed,ast2600-wdt";
-				reg = <0x1e785000 0x40>;
+				reg = <0x1e785000 0x40>, <0x1e6f2000 0x20>;
 			};
 
 			wdt2: watchdog at 1e785040 {
 				compatible = "aspeed,ast2600-wdt";
-				reg = <0x1e785040 0x40>;
+				reg = <0x1e785040 0x40>, <0x1e6f2000 0x020>;
 				status = "disabled";
 			};
 
 			wdt3: watchdog at 1e785080 {
 				compatible = "aspeed,ast2600-wdt";
-				reg = <0x1e785080 0x40>;
+				reg = <0x1e785080 0x40>, <0x1e6f2000 0x020>;
 				status = "disabled";
 			};
 
 			wdt4: watchdog at 1e7850c0 {
 				compatible = "aspeed,ast2600-wdt";
-				reg = <0x1e7850C0 0x40>;
+				reg = <0x1e7850C0 0x40>, <0x1e6f2000 0x020>;
 				status = "disabled";
 			};
 
diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
index b4773a6aaf8c..65118e461130 100644
--- a/drivers/watchdog/aspeed_wdt.c
+++ b/drivers/watchdog/aspeed_wdt.c
@@ -33,6 +33,7 @@ struct aspeed_wdt {
 	void __iomem		*base;
 	u32			ctrl;
 	const struct aspeed_wdt_config *cfg;
+	void __iomem		*sec_base;
 };
 
 static const struct aspeed_wdt_config ast2400_config = {
@@ -82,6 +83,15 @@ MODULE_DEVICE_TABLE(of, aspeed_wdt_of_table);
 #define WDT_RESET_MASK1		0x1c
 #define WDT_RESET_MASK2		0x20
 
+/*
+ * Only Ast2600 support
+ */
+#define   WDT_EVENT_COUNTER_MASK	(0xFFF << 8)
+#define   WDT_SECURE_ENGINE_STATUS	(0x14)
+#define   ABR_IMAGE_SOURCE		BIT(12)
+#define   ABR_IMAGE_SOURCE_SPI		BIT(13)
+#define   SECOND_BOOT_ENABLE		BIT(14)
+
 /*
  * WDT_RESET_WIDTH controls the characteristics of the external pulse (if
  * enabled), specifically:
@@ -313,6 +323,7 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
 	const char *reset_type;
 	u32 duration;
 	u32 status;
+	u32 sec_st;
 	int ret;
 
 	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
@@ -330,6 +341,12 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
 	if (IS_ERR(wdt->base))
 		return PTR_ERR(wdt->base);
 
+	if (of_device_is_compatible(np, "aspeed,ast2600-wdt")) {
+		wdt->sec_base = devm_platform_ioremap_resource(pdev, 1);
+		if (IS_ERR(wdt->sec_base))
+			return PTR_ERR(wdt->sec_base);
+	}
+
 	wdt->wdd.info = &aspeed_wdt_info;
 
 	if (wdt->cfg->irq_mask) {
@@ -459,12 +476,30 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
 	}
 
 	status = readl(wdt->base + WDT_TIMEOUT_STATUS);
-	if (status & WDT_TIMEOUT_STATUS_BOOT_SECONDARY) {
-		wdt->wdd.bootstatus = WDIOF_CARDRESET;
 
-		if (of_device_is_compatible(np, "aspeed,ast2400-wdt") ||
-		    of_device_is_compatible(np, "aspeed,ast2500-wdt"))
-			wdt->wdd.groups = bswitch_groups;
+	if (of_device_is_compatible(np, "aspeed,ast2600-wdt")) {
+		/*
+		 * The WDTn Timeout Status Register bit 1 is reserved.
+		 * To verify the second boot source,
+		 * we need to check SEC14 bit 12 and bit 13.
+		 */
+		sec_st = readl(wdt->sec_base + WDT_SECURE_ENGINE_STATUS);
+		if( sec_st & SECOND_BOOT_ENABLE)
+			if (sec_st & ABR_IMAGE_SOURCE ||
+			    sec_st & ABR_IMAGE_SOURCE_SPI)
+				wdt->wdd.bootstatus |= WDIOF_CARDRESET;
+
+		/*
+		 * To check Watchdog Event Count for WDIOF_EXTERN1
+		 */
+		if (status & WDT_EVENT_COUNTER_MASK) {
+			wdt->wdd.bootstatus |= WDIOF_EXTERN1;
+		}
+	} else {
+		wdt->wdd.groups = bswitch_groups;
+
+		if (status & WDT_TIMEOUT_STATUS_BOOT_SECONDARY)
+			wdt->wdd.bootstatus = WDIOF_CARDRESET;
 	}
 
 	dev_set_drvdata(dev, wdt);
-- 
2.25.1