ARM: imx: add low-level debug for vybrid

Add low-level debug support for vybrid, so that earlyprintk can be
enabled for debugging early boot issue.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

2 files changed, 34 insertions, 0 deletions

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 9762c84b4198..d597c6b8488b 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -386,6 +386,13 @@ choice
                   when u-boot hands over to the kernel, the system
                   silently crashes, with no serial output at all.
 
+        config DEBUG_VF_UART
+                bool "Vybrid UART"
+                depends on SOC_VF610
+                help
+                  Say Y here if you want kernel low-level debugging support
+                  on Vybrid based platforms.
+
         config DEBUG_NOMADIK_UART
                 bool "Kernel low-level debugging messages via NOMADIK UART"
                 depends on ARCH_NOMADIK
@@ -906,6 +913,7 @@ config DEBUG_LL_INCLUDE
         default "debug/tegra.S" if DEBUG_TEGRA_UART
         default "debug/ux500.S" if DEBUG_UX500_UART
         default "debug/vexpress.S" if DEBUG_VEXPRESS_UART0_DETECT
+        default "debug/vf.S" if DEBUG_VF_UART
         default "debug/vt8500.S" if DEBUG_VT8500_UART0
         default "debug/zynq.S" if DEBUG_ZYNQ_UART0 || DEBUG_ZYNQ_UART1
         default "mach/debug-macro.S"
diff --git a/arch/arm/include/debug/vf.S b/arch/arm/include/debug/vf.S
new file mode 100644
index 000000000000..ba12cc44b2cb
--- /dev/null
+++ b/arch/arm/include/debug/vf.S
@@ -0,0 +1,26 @@
+/*
+ * Copyright 2013 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+        .macro  addruart, rp, rv, tmp
+        ldr     \rp, =0x40028000        @ physical
+        ldr     \rv, =0xfe028000        @ virtual
+        .endm
+
+        .macro  senduart, rd, rx
+        strb    \rd, [\rx, #0x7]        @ Data Register
+        .endm
+
+        .macro  busyuart, rd, rx
+1001:   ldrb    \rd, [\rx, #0x4]        @ Status Register 1
+        tst     \rd, #1 << 6            @ TC
+        beq     1001b                   @ wait until transmit done
+        .endm
+
+        .macro  waituart,rd,rx
+        .endm