From 15d989e83d84ba13c100fbfe60980d22bf807fea Mon Sep 17 00:00:00 2001
From: Juergen Beisert <jbe@pengutronix.de>
Date: Wed, 18 Jul 2012 10:46:50 +0200
Subject: [PATCH] ARM/MXS: add reset cause detection

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/watchdog/im28wd.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/watchdog/im28wd.c b/drivers/watchdog/im28wd.c
index b016910ec..1f987deb7 100644
--- a/drivers/watchdog/im28wd.c
+++ b/drivers/watchdog/im28wd.c
@@ -21,6 +21,7 @@
 #include <errno.h>
 #include <malloc.h>
 #include <watchdog.h>
+#include <reset_source.h>
 
 #define MXS_RTC_CTRL 0x0
 #define MXS_RTC_SET_ADDR 0x4
@@ -73,6 +74,27 @@ static int imx28_watchdog_set_timeout(struct watchdog *wd, unsigned timeout)
 	return 0;
 }
 
+static void __maybe_unused imx28_detect_reset_source(const struct imx28_wd *p)
+{
+	u32 reg;
+
+	reg = readl(p->regs + MXS_RTC_PERSISTENT0);
+	if (reg & MXS_RTC_PERSISTENT0_EXT_RST) {
+		writel(MXS_RTC_PERSISTENT0_EXT_RST,
+			p->regs + MXS_RTC_PERSISTENT0 + MXS_RTC_CLR_ADDR);
+		set_reset_source(RESET_POR);
+		return;
+	}
+	if (reg & MXS_RTC_PERSISTENT0_THM_RST) {
+		writel(MXS_RTC_PERSISTENT0_THM_RST,
+			p->regs + MXS_RTC_PERSISTENT0 + MXS_RTC_CLR_ADDR);
+		set_reset_source(RESET_RST);
+		return;
+	}
+
+	set_reset_source(RESET_RST);
+}
+
 static int imx28_wd_probe(struct device_d *dev)
 {
 	struct imx28_wd *priv;
@@ -94,6 +116,9 @@ static int imx28_wd_probe(struct device_d *dev)
 	if (rc != 0)
 		goto on_error;
 
+	if (IS_ENABLED(CONFIG_RESET_SOURCE))
+		imx28_detect_reset_source(priv);
+
 	dev->priv = priv;
 	return 0;