From e8166d3e5937b8db43921b5049672b16af7f58e0 Mon Sep 17 00:00:00 2001
From: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
Date: Wed, 22 Mar 2023 15:27:22 -0500
Subject: feat(sbsa): helper api for refreshing watchdog timer

This patch adds a helper API to explicitly refresh SBSA secure watchdog
timer. Please refer section A.3 of the following spec:

https://developer.arm.com/documentation/den0029/latest/

Change-Id: I2d0943792aea0092bee1e51d74b908348587e66b
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
---
 changelog.yaml             |  3 +++
 drivers/arm/sbsa/sbsa.c    |  8 +++++++-
 include/drivers/arm/sbsa.h | 10 ++++++++--
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/changelog.yaml b/changelog.yaml
index 6dbb9b20d..c969b2c56 100644
--- a/changelog.yaml
+++ b/changelog.yaml
@@ -877,6 +877,9 @@ subsections:
                 deprecated:
                   - drivers/tzc380
 
+          - title: SBSA
+            scope: sbsa
+
       - title: Marvell
         scope: marvell-drivers
 
diff --git a/drivers/arm/sbsa/sbsa.c b/drivers/arm/sbsa/sbsa.c
index 79c6f2620..a88e20c04 100644
--- a/drivers/arm/sbsa/sbsa.c
+++ b/drivers/arm/sbsa/sbsa.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, ARM Limited. All rights reserved.
+ * Copyright (c) 2019-2023, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -40,3 +40,9 @@ void sbsa_wdog_stop(uintptr_t base)
 {
 	mmio_write_32(base + SBSA_WDOG_WCS_OFFSET, (0x0));
 }
+
+/* Refresh the secure watchdog timer explicitly */
+void sbsa_wdog_refresh(uintptr_t refresh_base)
+{
+	mmio_write_32(refresh_base + SBSA_WDOG_WRR_OFFSET, SBSA_WDOG_WRR_REFRESH);
+}
diff --git a/include/drivers/arm/sbsa.h b/include/drivers/arm/sbsa.h
index 9403634f7..4ca71942e 100644
--- a/include/drivers/arm/sbsa.h
+++ b/include/drivers/arm/sbsa.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, ARM Limited. All rights reserved.
+ * Copyright (c) 2019-2023, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -9,7 +9,12 @@
 
 #include <stdint.h>
 
-/* Register Offsets */
+/* SBSA Secure Watchdog Register Offsets */
+/* Refresh frame */
+#define SBSA_WDOG_WRR_OFFSET		UL(0x000)
+#define SBSA_WDOG_WRR_REFRESH		UL(0x1)
+
+/* Control and status frame */
 #define SBSA_WDOG_WCS_OFFSET		UL(0x000)
 #define SBSA_WDOG_WOR_LOW_OFFSET	UL(0x008)
 #define SBSA_WDOG_WOR_HIGH_OFFSET	UL(0x00C)
@@ -20,5 +25,6 @@
 
 void sbsa_wdog_start(uintptr_t base, uint64_t ms);
 void sbsa_wdog_stop(uintptr_t base);
+void sbsa_wdog_refresh(uintptr_t refresh_base);
 
 #endif /* SBSA_H */
-- 
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