[PATCH v2: For next 2/2] ARM: am33xx: Add support for reset reason detection

[Wadim Egorov]

Also activate in defconfig.

Signed-off-by: Wadim Egorov <w.egorov at phytec.de>
---
v2: Use the existing rest_source framework.
---
 arch/arm/configs/am335x_defconfig                |  1 +
 arch/arm/mach-omap/am33xx_generic.c              | 44 ++++++++++++++++++++++++
 arch/arm/mach-omap/include/mach/am33xx-silicon.h |  1 +
 3 files changed, 46 insertions(+)

diff --git a/arch/arm/configs/am335x_defconfig b/arch/arm/configs/am335x_defconfig
index f34a4c6..0b8f58d 100644
--- a/arch/arm/configs/am335x_defconfig
+++ b/arch/arm/configs/am335x_defconfig
@@ -24,6 +24,7 @@ CONFIG_MENU=y
 CONFIG_BLSPEC=y
 CONFIG_CONSOLE_ACTIVATE_NONE=y
 CONFIG_DEFAULT_ENVIRONMENT_GENERIC_NEW=y
+CONFIG_RESET_SOURCE=y
 CONFIG_DEBUG_INFO=y
 CONFIG_LONGHELP=y
 CONFIG_CMD_IOMEM=y
diff --git a/arch/arm/mach-omap/am33xx_generic.c b/arch/arm/mach-omap/am33xx_generic.c
index 912138d..67d6d8f 100644
--- a/arch/arm/mach-omap/am33xx_generic.c
+++ b/arch/arm/mach-omap/am33xx_generic.c
@@ -26,6 +26,7 @@
 #include <mach/sys_info.h>
 #include <mach/am33xx-generic.h>
 #include <mach/gpmc.h>
+#include <reset_source.h>
 
 void __noreturn am33xx_reset_cpu(unsigned long addr)
 {
@@ -152,6 +153,49 @@ static int am33xx_bootsource(void)
 	return 0;
 }
 
+static int am33xx_detect_reset_reason(void)
+{
+	static int init;
+	static uint32_t val;
+
+	if (!IS_ENABLED(CONFIG_RESET_SOURCE))
+		return 0;
+
+	if (!init) {
+		/* save value of AM33XX_PRM_RSTST register */
+		val = readl(AM33XX_PRM_RSTST);
+		/* clear AM33XX_PRM_RSTST - must be cleared by software
+		 * (warm reset insensitive) */
+		writel(val, AM33XX_PRM_RSTST);
+		init = 1;
+	}
+
+	switch (val) {
+	case (1 << 9):
+		reset_source_set(RESET_JTAG);
+		break;;
+	case (1 << 5):
+		reset_source_set(RESET_EXT);
+		break;
+	case (1 << 4):
+	case (1 << 3):
+		reset_source_set(RESET_WDG);
+		break;
+	case (1 << 1):
+		reset_source_set(RESET_RST);
+		break;
+	case (1 << 0):
+		reset_source_set(RESET_POR);
+		break;
+	default:
+		reset_source_set(RESET_UKWN);
+		break;
+	}
+
+	return 0;
+}
+device_initcall(am33xx_detect_reset_reason);
+
 int am33xx_register_ethaddr(int eth_id, int mac_id)
 {
 	void __iomem *mac_id_low = (void *)AM33XX_MAC_ID0_LO + mac_id * 8;
diff --git a/arch/arm/mach-omap/include/mach/am33xx-silicon.h b/arch/arm/mach-omap/include/mach/am33xx-silicon.h
index 4e63b43..7c209ec 100644
--- a/arch/arm/mach-omap/include/mach/am33xx-silicon.h
+++ b/arch/arm/mach-omap/include/mach/am33xx-silicon.h
@@ -68,6 +68,7 @@
 
 #define AM33XX_PRM_RSTCTRL		(AM33XX_PRM_BASE + 0x0f00)
 #define AM33XX_PRM_RSTCTRL_RESET	0x1
+#define AM33XX_PRM_RSTST		(AM33XX_PRM_BASE + 0x0f08)
 
 /* CTRL */
 #define AM33XX_CTRL_BASE		(AM33XX_L4_WKUP_BASE + 0x210000)
-- 
1.9.1