ARM: debug: stm32: add UART early console configuration for STM32F4

Early console is hardcoded on USART1 in current implementation.
With this patch, default UART instance is USART1, but other UART instances
can be configured by setting physical and virtual base addresses in
menuconfig.
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

arch/arm/Kconfig.debug

@@ -1201,12 +1201,13 @@ choice
 
 	config STM32F4_DEBUG_UART
 		bool "Use STM32F4 UART for low-level debug"
-		depends on ARCH_STM32
+		depends on MACH_STM32F429 || MACH_STM32F469
 		select DEBUG_STM32_UART
 		help
 		  Say Y here if you want kernel low-level debugging support
 		  on STM32F4 based platforms, which default UART is wired on
-		  USART1.
+		  USART1, but another UART instance can be selected by modifying
+		  CONFIG_DEBUG_UART_PHYS.
 
 		  If unsure, say N.
 
@@ -1619,6 +1620,7 @@ config DEBUG_UART_PHYS
 	default 0x3e000000 if DEBUG_BCM_KONA_UART
 	default 0x3f201000 if DEBUG_BCM2836
 	default 0x4000e400 if DEBUG_LL_UART_EFM32
+	default 0x40011000 if STM32F4_DEBUG_UART
 	default 0x40028000 if DEBUG_AT91_SAMV7_USART1
 	default 0x40081000 if DEBUG_LPC18XX_UART0
 	default 0x40090000 if DEBUG_LPC32XX
@@ -1713,7 +1715,7 @@ config DEBUG_UART_PHYS
 		DEBUG_S3C64XX_UART || \
 		DEBUG_BCM63XX_UART || DEBUG_ASM9260_UART || \
 		DEBUG_SIRFSOC_UART || DEBUG_DIGICOLOR_UA0 || \
-		DEBUG_AT91_UART
+		DEBUG_AT91_UART || DEBUG_STM32_UART
 
 config DEBUG_UART_VIRT
 	hex "Virtual base address of debug UART"
@@ -1823,7 +1825,7 @@ config DEBUG_UART_VIRT
 		DEBUG_S3C64XX_UART || \
 		DEBUG_BCM63XX_UART || DEBUG_ASM9260_UART || \
 		DEBUG_SIRFSOC_UART || DEBUG_DIGICOLOR_UA0 || \
-		DEBUG_AT91_UART
+		DEBUG_AT91_UART || DEBUG_STM32_UART
 
 config DEBUG_UART_8250_SHIFT
 	int "Register offset shift for the 8250 debug UART"

arch/arm/include/debug/stm32.S

@@ -4,8 +4,6 @@
  * Author:   Gerald Baeza <gerald.baeza@st.com> for STMicroelectronics.
  */
 
-#define STM32_UART_BASE			0x40011000	/* USART1 */
-
 #ifdef CONFIG_STM32F4_DEBUG_UART
 #define STM32_USART_SR_OFF		0x00
 #define STM32_USART_TDR_OFF		0x04
@@ -20,8 +18,8 @@
 #define STM32_USART_TXE			(1 << 7)	/* Tx data reg empty */
 
 .macro	addruart, rp, rv, tmp
-	ldr	\rp,      =STM32_UART_BASE	@ physical base
-	ldr	\rv,      =STM32_UART_BASE      @ virt base /* NoMMU */
+	ldr	\rp, =CONFIG_DEBUG_UART_PHYS @ physical base
+	ldr	\rv, =CONFIG_DEBUG_UART_VIRT @ virt base
 .endm
 
 .macro  senduart,rd,rx