[PATCH] arm64: zynqmp: enable the PMUFW watchdog

[Jorge Ramirez-Ortiz]

>From 528b3117a36b7b4eea1839afbea7191d60638b0c Mon Sep 17 00:00:00 2001
From: Jorge Ramirez-Ortiz <jorge at foundries.io>
Date: Wed, 23 Mar 2022 14:41:15 +0100
Subject: [PATCH] arm64: zynqmp: enable the PMUFW watchdog

If the PMUFW was built with support for the CSU watchdog we must let the
firmware know that it can be started.

We do this by faking the FSBL done state.

Reference code in PMUFW:
https://github.com/Xilinx/embeddedsw/blob/master/lib/sw_apps/zynqmp_pmufw/src/xpfw_mod_common.c#L36

It needs this fix on the PMUFW
https://github.com/Xilinx/embeddedsw/pull/190

Signed-off-by: Jorge Ramirez-Ortiz <jorge at foundries.io>
---
 arch/arm/mach-zynqmp/include/mach/hardware.h | 5 ++++-
 board/xilinx/zynqmp/zynqmp.c                 | 4 ++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-zynqmp/include/mach/hardware.h b/arch/arm/mach-zynqmp/include/mach/hardware.h
index a70d6d611b..24c3ef3d7d 100644
--- a/arch/arm/mach-zynqmp/include/mach/hardware.h
+++ b/arch/arm/mach-zynqmp/include/mach/hardware.h
@@ -174,8 +174,11 @@ struct csu_regs {
 
 #define ZYNQMP_PMU_BASEADDR	0xFFD80000
 
+#define FSBL_COMPLETION	0x1
+
 struct pmu_regs {
-	u32 reserved[18];
+	u32 reserved[17];
+	u32 gen_storage5; /* 0x44 */
 	u32 gen_storage6; /* 0x48 */
 };
 
diff --git a/board/xilinx/zynqmp/zynqmp.c b/board/xilinx/zynqmp/zynqmp.c
index 70b3c81f12..c88c5fb8ea 100644
--- a/board/xilinx/zynqmp/zynqmp.c
+++ b/board/xilinx/zynqmp/zynqmp.c
@@ -419,6 +419,10 @@ int board_init(void)
 						zynqmp_pm_cfg_obj_size);
 	printf("Silicon version:\t%d\n", zynqmp_get_silicon_version());
 
+	/* fake FSBL completion to start the PMUFW watchdog when enabled */
+	writel(readl(&pmu_base->gen_storage5) | FSBL_COMPLETION,
+	       &pmu_base->gen_storage5);
+
 	/* the CSU disables the JTAG interface when secure boot is enabled */
 	if (CONFIG_IS_ENABLED(ZYNQMP_RESTORE_JTAG))
 		restore_jtag();
-- 
2.34.1