[PATCH linux dev-4.10 v2 3/4] watchdog: aspeed: Support external signal drive and polarity bindings

[Andrew Jeffery <andrew@aj.id.au>]

These bindings are optional, and only relevant on the AST2500 and
compatible watchdog controllers.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
---
 drivers/watchdog/aspeed_wdt.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
index d29f75e90bb6..9a07ef176054 100644
--- a/drivers/watchdog/aspeed_wdt.c
+++ b/drivers/watchdog/aspeed_wdt.c
@@ -42,6 +42,9 @@ MODULE_DEVICE_TABLE(of, aspeed_wdt_of_table);
 #define   WDT_CTRL_WDT_INTR		BIT(2)
 #define   WDT_CTRL_RESET_SYSTEM		BIT(1)
 #define   WDT_CTRL_ENABLE		BIT(0)
+#define WDT_RESET_WIDTH		0x18
+#define   WDT_RESET_WIDTH_ACTIVE_HIGH	BIT(31)
+#define   WDT_RESET_WIDTH_PUSHPULL	BIT(30)
 
 #define WDT_RESTART_MAGIC	0x4755
 
@@ -204,6 +207,24 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
 		set_bit(WDOG_HW_RUNNING, &wdt->wdd.status);
 	}
 
+	if (of_device_is_compatible(np, "aspeed,ast2500-wdt")) {
+		u32 from = readl(wdt->base + WDT_RESET_WIDTH);
+		u32 to = from;
+
+		if (of_property_read_bool(np, "aspeed,ext-push-pull"))
+			to |= WDT_RESET_WIDTH_PUSHPULL;
+		else
+			to &= ~WDT_RESET_WIDTH_PUSHPULL;
+
+		if (of_property_read_bool(np, "aspeed,ext-active-high"))
+			to |= WDT_RESET_WIDTH_ACTIVE_HIGH;
+		else
+			to &= ~WDT_RESET_WIDTH_ACTIVE_HIGH;
+
+		if (from != to)
+			writel(to, wdt->base + WDT_RESET_WIDTH);
+	}
+
 	ret = watchdog_register_device(&wdt->wdd);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to register\n");
-- 
2.11.0