ARM: vf610: add UART choice for low-level debug

Add choice for low-level debug UART. Similar to i.MX6, there is a
numeric configuration, valid choices are 0 to 3.
Note that the kernel assumes that the boot loader initialized clock
properly.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

2 files changed, 22 insertions, 2 deletions

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index eab8ecbe69c1..00c69503da22 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -942,6 +942,15 @@ config DEBUG_IMX_UART_PORT
           Choose UART port on which kernel low-level debug messages
           should be output.
 
+config DEBUG_VF_UART_PORT
+        int "Vybrid Debug UART Port Selection" if DEBUG_VF_UART
+        default 1
+        range 0 3
+        depends on SOC_VF610
+        help
+          Choose UART port on which kernel low-level debug messages
+          should be output.
+
 config DEBUG_TEGRA_UART
         bool
         depends on ARCH_TEGRA
diff --git a/arch/arm/include/debug/vf.S b/arch/arm/include/debug/vf.S
index ba12cc44b2cb..b88933849a17 100644
--- a/arch/arm/include/debug/vf.S
+++ b/arch/arm/include/debug/vf.S
@@ -7,9 +7,20 @@
  *
  */
 
+#define VF_UART0_BASE_ADDR      0x40027000
+#define VF_UART1_BASE_ADDR      0x40028000
+#define VF_UART2_BASE_ADDR      0x40029000
+#define VF_UART3_BASE_ADDR      0x4002a000
+#define VF_UART_BASE_ADDR(n)    VF_UART##n##_BASE_ADDR
+#define VF_UART_BASE(n)         VF_UART_BASE_ADDR(n)
+#define VF_UART_PHYSICAL_BASE   VF_UART_BASE(CONFIG_DEBUG_VF_UART_PORT)
+
+#define VF_UART_VIRTUAL_BASE    0xfe000000
+
         .macro  addruart, rp, rv, tmp
-        ldr     \rp, =0x40028000        @ physical
-        ldr     \rv, =0xfe028000        @ virtual
+        ldr     \rp, =VF_UART_PHYSICAL_BASE     @ physical
+        and     \rv, \rp, #0xffffff             @ offset within 16MB section
+        add     \rv, \rv, #VF_UART_VIRTUAL_BASE
         .endm
 
         .macro  senduart, rd, rx