ARM: sti: Add DEBUG_LL console support

This patch adds low level debug uart support to sti based SOCs.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
CC: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Olof Johansson <olof@lixom.net>
diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 1d41908..311f6f3 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -483,6 +483,16 @@
 		  This option selects UART0 on VIA/Wondermedia System-on-a-chip
 		  devices, including VT8500, WM8505, WM8650 and WM8850.
 
+	config DEBUG_STI_UART
+		depends on ARCH_STI
+		bool "Use StiH415/416 ASC for low-level debug"
+		help
+		  Say Y here if you want kernel low-level debugging support
+		  on StiH415/416 based platforms like B2000, B2020.
+		  It support UART2 and SBC_UART1.
+
+		  If unsure, say N.
+
 	config DEBUG_LL_UART_NONE
 		bool "No low-level debugging UART"
 		depends on !ARCH_MULTIPLATFORM
@@ -617,6 +627,30 @@
 
 endchoice
 
+choice
+	prompt "Low-level debug console UART"
+	depends on DEBUG_LL && DEBUG_STI_UART
+
+	config STIH41X_DEBUG_ASC2
+		bool "ASC2 UART"
+		help
+		  Say Y here if you want kernel low-level debugging support
+		  on STiH415/416 based platforms like b2000, which has
+		  default UART wired up to ASC2.
+
+		  If unsure, say N.
+
+	config STIH41X_DEBUG_SBC_ASC1
+		bool "SBC ASC1 UART"
+		help
+		  Say Y here if you want kernel low-level debugging support
+		  on STiH415/416 based platforms like b2020. which has
+		  default UART wired up to SBC ASC1.
+
+		  If unsure, say N.
+
+endchoice
+
 config DEBUG_LL_INCLUDE
 	string
 	default "debug/bcm2835.S" if DEBUG_BCM2835
@@ -641,6 +675,7 @@
 				 DEBUG_MMP_UART3
 	default "debug/sirf.S" if DEBUG_SIRFPRIMA2_UART1 || DEBUG_SIRFMARCO_UART1
 	default "debug/socfpga.S" if DEBUG_SOCFPGA_UART
+	default "debug/sti.S" if DEBUG_STI_UART
 	default "debug/sunxi.S" if DEBUG_SUNXI_UART0 || DEBUG_SUNXI_UART1
 	default "debug/tegra.S" if DEBUG_TEGRA_UART
 	default "debug/ux500.S" if DEBUG_UX500_UART