ARM/Samsung: add support to detect the reset source

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 56 insertions, 0 deletions

diff --git a/arch/arm/mach-samsung/reset_source.c b/arch/arm/mach-samsung/reset_source.c
new file mode 100644
index 0000000000..2456e3f602
--- /dev/null
+++ b/arch/arm/mach-samsung/reset_source.c
@@ -0,0 +1,56 @@
+/*
+ * (C) Copyright 2012 Juergen Beisert - <kernel@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <common.h>
+#include <init.h>
+#include <io.h>
+#include <reset_source.h>
+#include <mach/s3c-iomap.h>
+
+/* S3C2440 relevant */
+#define S3C2440_GSTATUS2 0xb4
+# define S3C2440_GSTATUS2_PWRST (1 << 0)
+# define S3C2440_GSTATUS2_SLEEPRST (1 << 1)
+# define S3C2440_GSTATUS2_WDRST (1 << 2)
+
+static int s3c_detect_reset_source(void)
+{
+	u32 reg = readl(S3C_GPIO_BASE + S3C2440_GSTATUS2);
+
+	if (reg & S3C2440_GSTATUS2_PWRST) {
+		set_reset_source(RESET_POR);
+		writel(S3C2440_GSTATUS2_PWRST,
+					S3C_GPIO_BASE + S3C2440_GSTATUS2);
+		return 0;
+	}
+
+	if (reg & S3C2440_GSTATUS2_SLEEPRST) {
+		set_reset_source(RESET_WKE);
+		writel(S3C2440_GSTATUS2_SLEEPRST,
+					S3C_GPIO_BASE + S3C2440_GSTATUS2);
+		return 0;
+	}
+
+	if (reg & S3C2440_GSTATUS2_WDRST) {
+		set_reset_source(RESET_WDG);
+		writel(S3C2440_GSTATUS2_WDRST,
+					S3C_GPIO_BASE + S3C2440_GSTATUS2);
+		return 0;
+	}
+
+	/* else keep the default 'unknown' state */
+	return 0;
+}
+
+device_initcall(s3c_detect_reset_source);