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>

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 9762c84..d597c6b 100644 (file)
--- 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 (file)
index 0000000..ba12cc4
--- /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