ARM: sunxi: Add earlyprintk support for UART0 (sun4i)

Signed-off-by: Stefan Roese <sr@denx.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/Kconfig.debug

@@ -345,6 +345,13 @@ choice
 		  Say Y here if you want kernel low-level debugging support
 		  on SOCFPGA based platforms.
 
+	config DEBUG_SUNXI_UART0
+		bool "Kernel low-level debugging messages via sunXi UART0"
+		depends on ARCH_SUNXI
+		help
+		  Say Y here if you want kernel low-level debugging support
+		  on Allwinner A1X based platforms on the UART0.
+
 	config DEBUG_SUNXI_UART1
 		bool "Kernel low-level debugging messages via sunXi UART1"
 		depends on ARCH_SUNXI
@@ -423,7 +430,7 @@ config DEBUG_LL_INCLUDE
 	default "debug/mvebu.S" if DEBUG_MVEBU_UART
 	default "debug/picoxcell.S" if DEBUG_PICOXCELL_UART
 	default "debug/socfpga.S" if DEBUG_SOCFPGA_UART
-	default "debug/sunxi.S" if DEBUG_SUNXI_UART1
+	default "debug/sunxi.S" if DEBUG_SUNXI_UART0 || DEBUG_SUNXI_UART1
 	default "debug/vexpress.S" if DEBUG_VEXPRESS_UART0_DETECT || \
 		DEBUG_VEXPRESS_UART0_CA9 || DEBUG_VEXPRESS_UART0_RS1
 	default "mach/debug-macro.S"

arch/arm/include/debug/sunxi.S

@@ -10,7 +10,10 @@
  * published by the Free Software Foundation.
 */
 
-#ifdef CONFIG_DEBUG_SUNXI_UART1
+#if defined(CONFIG_DEBUG_SUNXI_UART0)
+#define SUNXI_UART_DEBUG_PHYS_BASE 0x01c28000
+#define SUNXI_UART_DEBUG_VIRT_BASE 0xf1c28000
+#elif defined(CONFIG_DEBUG_SUNXI_UART1)
 #define SUNXI_UART_DEBUG_PHYS_BASE 0x01c28400
 #define SUNXI_UART_DEBUG_VIRT_BASE 0xf1c28400
 #endif