[PATCH v3 4/4] ARM: debug: stm32: add UART early console support for STM32MP1

[Erwan Le Ray]

Add support of early console for STM32MP1. Default UART instance is UART4,
but other UART instances can be configured by setting physical and virtual
base addresses in menuconfig.

Signed-off-by: Erwan Le Ray <erwan.leray@xxxxxx>

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index e5e1703a89c0..3357e294a7cc 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -1235,6 +1235,18 @@ choice
 
 		  If unsure, say N.
 
+	config STM32MP1_DEBUG_UART
+		bool "Use STM32MP1 UART for low-level debug"
+		depends on MACH_STM32MP157
+		select DEBUG_STM32_UART
+		help
+		  Say Y here if you want kernel low-level debugging support
+		  on STM32MP1 based platforms, wich default UART is wired on
+		  UART4, but another UART instance can be selected by modifying
+		  CONFIG_DEBUG_UART_PHYS and CONFIG_DEBUG_UART_VIRT.
+
+		  If unsure, say N.
+
 	config TEGRA_DEBUG_UART_AUTO_ODMDATA
 		bool "Kernel low-level debugging messages via Tegra UART via ODMDATA"
 		depends on ARCH_TEGRA
@@ -1633,6 +1645,7 @@ config DEBUG_UART_PHYS
 	default 0x3e000000 if DEBUG_BCM_KONA_UART
 	default 0x3f201000 if DEBUG_BCM2836
 	default 0x4000e400 if DEBUG_LL_UART_EFM32
+	default 0x40010000 if STM32MP1_DEBUG_UART
 	default 0x40011000 if STM32F4_DEBUG_UART || STM32F7_DEBUG_UART || \
 				STM32H7_DEBUG_UART
 	default 0x40028000 if DEBUG_AT91_SAMV7_USART1
@@ -1795,6 +1808,7 @@ config DEBUG_UART_VIRT
 	default 0xfcfe8600 if DEBUG_BCM63XX_UART
 	default 0xfd000000 if DEBUG_SPEAR3XX || DEBUG_SPEAR13XX
 	default 0xfd883000 if DEBUG_ALPINE_UART0
+	default 0xfe010000 if STM32MP1_DEBUG_UART
 	default 0xfe017000 if DEBUG_MMP_UART2
 	default 0xfe018000 if DEBUG_MMP_UART3
 	default 0xfe100000 if DEBUG_IMX23_UART || DEBUG_IMX28_UART
diff --git a/arch/arm/include/debug/stm32.S b/arch/arm/include/debug/stm32.S
index 5a2e2b065340..f3c4a37210ed 100644
--- a/arch/arm/include/debug/stm32.S
+++ b/arch/arm/include/debug/stm32.S
@@ -9,7 +9,8 @@
 #define STM32_USART_TDR_OFF		0x04
 #endif
 
-#if defined(CONFIG_STM32F7_DEBUG_UART) || defined(CONFIG_STM32H7_DEBUG_UART)
+#if defined(CONFIG_STM32F7_DEBUG_UART) || defined(CONFIG_STM32H7_DEBUG_UART) || \
+	defined(CONFIG_STM32MP1_DEBUG_UART)
 #define STM32_USART_SR_OFF		0x1C
 #define STM32_USART_TDR_OFF		0x28
 #endif
-- 
2.17.1