Merge patch series "arm: mach-k3: am64x: Add reset cause for cpuinfo"

Steffen Kothe <[email protected]> says:

AM64X hereby receives support for reset reason printing during boot.

Unfortunately does the AM64X register mapping slighlty differ from
the AM62X. WDT and PORZ are not part of the reset source register, but
the mapping remains the same for all other causes.

To prevent ifdef/else constructs, I decided to follow a simple
copy/paste approach and adjusted the logic accordingly.

Link: https://lore.kernel.org/r/[email protected]

2 files changed, 54 insertions, 0 deletions

diff --git a/arch/arm/mach-k3/am64x/boot.c b/arch/arm/mach-k3/am64x/boot.c
index ce8ae941be6..bf8e1a5cb44 100644
--- a/arch/arm/mach-k3/am64x/boot.c
+++ b/arch/arm/mach-k3/am64x/boot.c
@@ -103,3 +103,39 @@ u32 get_boot_device(void)
 
 	return bootmedia;
 }
+
+const char *get_reset_reason(void)
+{
+	u32 reset_reason = readl(CTRLMMR_MCU_RST_SRC);
+
+	/* After reading reset source register, software must clear it */
+	if (reset_reason)
+		writel(reset_reason, CTRLMMR_MCU_RST_SRC);
+
+	if (reset_reason == 0 ||
+	    (reset_reason & (RST_SRC_SW_MAIN_POR_FROM_MAIN |
+			    RST_SRC_SW_MAIN_POR_FROM_MCU)))
+		return "POR";
+
+	if (reset_reason & (RST_SRC_SAFETY_ERR | RST_SRC_MAIN_ESM_ERR))
+		return "ESM";
+
+	if (reset_reason & (RST_SRC_SW_MAIN_WARM_FROM_MAIN |
+			    RST_SRC_SW_MAIN_WARM_FROM_MCU  |
+			    RST_SRC_SW_MCU_WARM_RST))
+		return "RST";
+
+	if (reset_reason & (RST_SRC_SMS_WARM_RST | RST_SRC_SMS_COLD_RST))
+		return "DMSC";
+
+	if (reset_reason & RST_SRC_DEBUG_RST)
+		return "JTAG";
+
+	if (reset_reason & RST_SRC_THERMAL_RST)
+		return "THERMAL";
+
+	if (reset_reason & (RST_SRC_MAIN_RESET_PIN | RST_SRC_MCU_RESET_PIN))
+		return "PIN";
+
+	return "UNKNOWN";
+}
diff --git a/arch/arm/mach-k3/include/mach/am64_hardware.h b/arch/arm/mach-k3/include/mach/am64_hardware.h
index 105b42986de..2717da07690 100644
--- a/arch/arm/mach-k3/include/mach/am64_hardware.h
+++ b/arch/arm/mach-k3/include/mach/am64_hardware.h
@@ -46,6 +46,24 @@
 /* Use Last 2K as Scratch pad */
 #define TI_SRAM_SCRATCH_BOARD_EEPROM_START		0x7019f800
 
+/* Reset Reason Detection */
+#define CTRLMMR_MCU_RST_SRC			(MCU_CTRL_MMR0_BASE + 0x18178)
+
+/* Reset causes by bit mapping */
+#define RST_SRC_SAFETY_ERR			BIT(31)
+#define RST_SRC_MAIN_ESM_ERR			BIT(30)
+#define RST_SRC_SW_MAIN_POR_FROM_MAIN		BIT(25)
+#define RST_SRC_SW_MAIN_POR_FROM_MCU		BIT(24)
+#define RST_SRC_SW_MAIN_WARM_FROM_MAIN		BIT(21)
+#define RST_SRC_SW_MAIN_WARM_FROM_MCU		BIT(20)
+#define RST_SRC_SW_MCU_WARM_RST			BIT(16)
+#define RST_SRC_SMS_WARM_RST			BIT(13)
+#define RST_SRC_SMS_COLD_RST			BIT(12)
+#define RST_SRC_DEBUG_RST			BIT(8)
+#define RST_SRC_THERMAL_RST			BIT(4)
+#define RST_SRC_MAIN_RESET_PIN			BIT(2)
+#define RST_SRC_MCU_RESET_PIN			BIT(0)
+
 #if defined(CONFIG_SYS_K3_SPL_ATF) && !defined(__ASSEMBLY__)
 
 #define AM64X_DEV_RTI8			127