ARM: zx: add low level debug support for zx296702

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>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 8e354a7..1515cb6 100644 (file)
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -1166,6 +1166,18 @@ 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"
+               select DEBUG_UART_PL01X
+               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
@@ -1346,6 +1358,7 @@ config DEBUG_UART_PHYS
        default 0x02531000 if DEBUG_KEYSTONE_UART1
        default 0x03010fe0 if ARCH_RPC
        default 0x07000000 if DEBUG_SUN9I_UART0
+       default 0x09405000 if DEBUG_ZTE_ZX
        default 0x10009000 if DEBUG_REALVIEW_STD_PORT || \
                                DEBUG_VEXPRESS_UART0_CA9
        default 0x1010c000 if DEBUG_REALVIEW_PB1176_PORT
@@ -1477,6 +1490,7 @@ config DEBUG_UART_VIRT
        default 0xfb009000 if DEBUG_REALVIEW_STD_PORT
        default 0xfb10c000 if DEBUG_REALVIEW_PB1176_PORT
        default 0xfc40ab00 if DEBUG_BRCMSTB_UART
+       default 0xfc705000 if DEBUG_ZTE_ZX
        default 0xfcfe8600 if DEBUG_UART_BCM63XX
        default 0xfd000000 if ARCH_SPEAR3XX || ARCH_SPEAR6XX
        default 0xfd000000 if ARCH_SPEAR13XX

diff --git a/arch/arm/include/debug/pl01x.S b/arch/arm/include/debug/pl01x.S
index 92ef808..f7d8323 100644 (file)
--- a/arch/arm/include/debug/pl01x.S
+++ b/arch/arm/include/debug/pl01x.S
@@ -12,6 +12,13 @@
 */
 #include <linux/amba/serial.h>
 
+#ifdef CONFIG_DEBUG_ZTE_ZX
+#undef UART01x_DR
+#undef UART01x_FR
+#define UART01x_DR     0x04
+#define UART01x_FR     0x14
+#endif
+
 #ifdef CONFIG_DEBUG_UART_PHYS
                .macro  addruart, rp, rv, tmp
                ldr     \rp, =CONFIG_DEBUG_UART_PHYS