[PATCH 02/10] ARM: zx: add low level debug support

[jun.nie@linaro.org (Jun Nie)]

Use the UART0 peripheral for low level debug. Only the UART port 0 is
currently supported.

Signed-off-by: Jun Nie <jun.nie@linaro.org>
---
 arch/arm/Kconfig.debug      | 12 ++++++++++++
 arch/arm/include/debug/zx.S | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)
 create mode 100644 arch/arm/include/debug/zx.S

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 970de75..b2a0e9a 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -1169,6 +1169,17 @@ choice
 		  For more details about semihosting, please see
 		  chapter 8 of DUI0203I_rvct_developer_guide.pdf from ARM Ltd.
 
+	config DEBUG_ZTE_ZX
+		bool "Use ZTE ZX UART"
+		depends on ARCH_ZX
+		help
+		  Say Y here if you are enabling ZTE ZX296702 SOC and need
+		  debug uart support.
+
+		  This option is preferred over the platform specific
+		  options; the platform specific options are deprecated
+		  and will be soon removed.
+
 	config DEBUG_LL_UART_8250
 		bool "Kernel low-level debugging via 8250 UART"
 		help
@@ -1315,6 +1326,7 @@ config DEBUG_LL_INCLUDE
 	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/zx.S" if DEBUG_ZTE_ZX
 	default "debug/zynq.S" if DEBUG_ZYNQ_UART0 || DEBUG_ZYNQ_UART1
 	default "debug/bcm63xx.S" if DEBUG_UART_BCM63XX
 	default "debug/digicolor.S" if DEBUG_DIGICOLOR_UA0
diff --git a/arch/arm/include/debug/zx.S b/arch/arm/include/debug/zx.S
new file mode 100644
index 0000000..aa745ac
--- /dev/null
+++ b/arch/arm/include/debug/zx.S
@@ -0,0 +1,35 @@
+/*
+ * Debugging macro include header
+ *
+ * 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.
+ *
+ */
+
+#define UART01x_DR              0x04    /* Data read or write */
+#define UART01x_FR              0x14    /* Flag register (Read only) */
+
+#define UART01x_FR_TXFF         0x020
+
+
+#define UART0_PADDR		0x09405000
+#define UART0_VADDR		0xfc705000
+
+		.macro	addruart, rp, rv, tmp
+		ldr	\rp, =UART0_PADDR	@ physical
+		ldr	\rv, =UART0_VADDR	@ virtual
+		.endm
+
+		.macro	senduart,rd,rx
+		strb	\rd, [\rx, #UART01x_DR]
+		.endm
+
+		.macro	waituart,rd,rx
+		.endm
+
+		.macro  busyuart,rd,rx
+1001:		ldr	\rd, [\rx, #UART01x_FR]
+		tst	\rd, #UART01x_FR_TXFF
+		bne	1001b
+		.endm
-- 
1.9.1