fix(plat/st): add UART reset in crash console init
Add the reset set/clear sequence at the beginning of the function
plat_crash_console_init(). If not done, there is a risk that the UART
is in a bad state and will not be able to print correct characters.
Change-Id: Id31e28773d6c4f26f16d3569d1e3c5aa0e26e039
Signed-off-by: Yann Gautier <yann.gautier@st.com>
diff --git a/plat/st/stm32mp1/stm32mp1_def.h b/plat/st/stm32mp1/stm32mp1_def.h
index 0d36660..469c2d9 100644
--- a/plat/st/stm32mp1/stm32mp1_def.h
+++ b/plat/st/stm32mp1/stm32mp1_def.h
@@ -205,6 +205,8 @@
#define DEBUG_UART_TX_CLKSRC RCC_UART24CKSELR_HSI
#define DEBUG_UART_TX_EN_REG RCC_MP_APB1ENSETR
#define DEBUG_UART_TX_EN RCC_MP_APB1ENSETR_UART4EN
+#define DEBUG_UART_RST_REG RCC_APB1RSTSETR
+#define DEBUG_UART_RST_BIT RCC_APB1RSTSETR_UART4RST
/*******************************************************************************
* STM32MP1 ETZPC
diff --git a/plat/st/stm32mp1/stm32mp1_helper.S b/plat/st/stm32mp1/stm32mp1_helper.S
index 84e9e8d..cac9752 100644
--- a/plat/st/stm32mp1/stm32mp1_helper.S
+++ b/plat/st/stm32mp1/stm32mp1_helper.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2021, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -148,6 +148,19 @@
* ---------------------------------------------
*/
func plat_crash_console_init
+ /* Reset UART peripheral */
+ ldr r1, =(RCC_BASE + DEBUG_UART_RST_REG)
+ ldr r2, =DEBUG_UART_RST_BIT
+ str r2, [r1]
+1:
+ ldr r0, [r1]
+ ands r2, r0, r2
+ beq 1b
+ str r2, [r1, #4] /* RSTCLR register */
+2:
+ ldr r0, [r1]
+ ands r2, r0, r2
+ bne 2b
/* Enable GPIOs for UART TX */
ldr r1, =(RCC_BASE + DEBUG_UART_TX_GPIO_BANK_CLK_REG)
ldr r2, [r1]