arm: mach-k3: am62x: Implement get_reset_reason()

Implement get_reset_reason() for AM62x to enable reporting of
the reset cause in the cpuinfo output.

Signed-off-by: Wadim Egorov <w.egorov@phytec.de>

diff --git a/arch/arm/mach-k3/am62x/boot.c b/arch/arm/mach-k3/am62x/boot.c
index 132b42f7edb303030a23fa83e67e27b9d3f4ceb5..a3a6cda6bdb6df3506540d646d6d0effb117eff7 100644 (file)
--- a/arch/arm/mach-k3/am62x/boot.c
+++ b/arch/arm/mach-k3/am62x/boot.c
@@ -101,3 +101,43 @@ 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 |
+                           RST_SRC_DS_MAIN_PORZ)))
+               return "POR";
+
+       if (reset_reason & (RST_SRC_SAFETY_ERR | RST_SRC_MAIN_ESM_ERR))
+               return "ESM";
+
+       if (reset_reason & RST_SRC_DM_WDT_RST)
+               return "WDOG";
+
+       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/am62_hardware.h b/arch/arm/mach-k3/include/mach/am62_hardware.h
index bcbc4821c82f5154ec4605fe6c09cff02f6f7c50..c33362696c44c1ace9b3eea370449c85d95fe298 100644 (file)
--- a/arch/arm/mach-k3/include/mach/am62_hardware.h
+++ b/arch/arm/mach-k3/include/mach/am62_hardware.h
@@ -79,6 +79,25 @@
 
 #define CTRLMMR_MCU_RST_CTRL                   (MCU_CTRL_MMR0_BASE + 0x18170)
 
+/* Reset Reason Detection */
+#define CTRLMMR_MCU_RST_SRC                    (MCU_CTRL_MMR0_BASE + 0x18178)
+
+#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_DS_MAIN_PORZ                   BIT(23)
+#define RST_SRC_DM_WDT_RST                     BIT(22)
+#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)
+
 /* Debounce register configuration */
 #define CTRLMMR_DBOUNCE_CFG(index)             (MCU_CTRL_MMR0_BASE + 0x4080 + (index * 4))