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-rw-r--r--Documentation/devicetree/bindings/watchdog/fsl-imx-wdt.txt4
-rw-r--r--drivers/watchdog/imx2_wdt.c19
2 files changed, 20 insertions, 3 deletions
diff --git a/Documentation/devicetree/bindings/watchdog/fsl-imx-wdt.txt b/Documentation/devicetree/bindings/watchdog/fsl-imx-wdt.txt
index 8dab6fd024aa..107280ef0025 100644
--- a/Documentation/devicetree/bindings/watchdog/fsl-imx-wdt.txt
+++ b/Documentation/devicetree/bindings/watchdog/fsl-imx-wdt.txt
@@ -5,10 +5,12 @@ Required properties:
- reg : Should contain WDT registers location and length
- interrupts : Should contain WDT interrupt
-Optional property:
+Optional properties:
- big-endian: If present the watchdog device's registers are implemented
in big endian mode, otherwise in native mode(same with CPU), for more
detail please see: Documentation/devicetree/bindings/regmap/regmap.txt.
+- fsl,ext-reset-output: If present the watchdog device is configured to
+ assert its external reset (WDOG_B) instead of issuing a software reset.
Examples:
diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
index 331aed831dac..62f346bb4348 100644
--- a/drivers/watchdog/imx2_wdt.c
+++ b/drivers/watchdog/imx2_wdt.c
@@ -37,6 +37,8 @@
#define IMX2_WDT_WCR 0x00 /* Control Register */
#define IMX2_WDT_WCR_WT (0xFF << 8) /* -> Watchdog Timeout Field */
+#define IMX2_WDT_WCR_WDA (1 << 5) /* -> External Reset WDOG_B */
+#define IMX2_WDT_WCR_SRS (1 << 4) /* -> Software Reset Signal */
#define IMX2_WDT_WCR_WRE (1 << 3) /* -> WDOG Reset Enable */
#define IMX2_WDT_WCR_WDE (1 << 2) /* -> Watchdog Enable */
#define IMX2_WDT_WCR_WDZST (1 << 0) /* -> Watchdog timer Suspend */
@@ -59,6 +61,7 @@ struct imx2_wdt_device {
struct clk *clk;
struct regmap *regmap;
struct watchdog_device wdog;
+ bool ext_reset;
};
static bool nowayout = WATCHDOG_NOWAYOUT;
@@ -83,6 +86,12 @@ static int imx2_wdt_restart(struct watchdog_device *wdog, unsigned long action,
struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
unsigned int wcr_enable = IMX2_WDT_WCR_WDE;
+ /* Use internal reset or external - not both */
+ if (wdev->ext_reset)
+ wcr_enable |= IMX2_WDT_WCR_SRS; /* do not assert int reset */
+ else
+ wcr_enable |= IMX2_WDT_WCR_WDA; /* do not assert ext-reset */
+
/* Assert SRS signal */
regmap_write(wdev->regmap, IMX2_WDT_WCR, wcr_enable);
/*
@@ -112,8 +121,12 @@ static inline void imx2_wdt_setup(struct watchdog_device *wdog)
val |= IMX2_WDT_WCR_WDZST;
/* Strip the old watchdog Time-Out value */
val &= ~IMX2_WDT_WCR_WT;
- /* Generate reset if WDOG times out */
- val &= ~IMX2_WDT_WCR_WRE;
+ /* Generate internal chip-level reset if WDOG times out */
+ if (!wdev->ext_reset)
+ val &= ~IMX2_WDT_WCR_WRE;
+ /* Or if external-reset assert WDOG_B reset only on time-out */
+ else
+ val |= IMX2_WDT_WCR_WRE;
/* Keep Watchdog Disabled */
val &= ~IMX2_WDT_WCR_WDE;
/* Set the watchdog's Time-Out value */
@@ -230,6 +243,8 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
regmap_read(wdev->regmap, IMX2_WDT_WRSR, &val);
wdog->bootstatus = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0;
+ wdev->ext_reset = of_property_read_bool(pdev->dev.of_node,
+ "fsl,ext-reset-output");
wdog->timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME);
if (wdog->timeout != timeout)
dev_warn(&pdev->dev, "Initial timeout out of range! Clamped from %u to %u\n",