msm: make debugging UART (for DEBUG_LL) configurable

Provides options to select one of the three "lowspeed" UARTs
on MSM7k SoCs for DEBUG_LL output from the zImage decompressor
and kernel.

Signed-off-by: Brian Swetland <swetland@google.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>

5 files changed, 63 insertions, 7 deletions

diff --git a/arch/arm/mach-msm/Kconfig b/arch/arm/mach-msm/Kconfig
index d140abca690..35f2a90a2af 100644
--- a/arch/arm/mach-msm/Kconfig
+++ b/arch/arm/mach-msm/Kconfig
@@ -3,6 +3,30 @@ if ARCH_MSM
 comment "MSM Board Type"
         depends on ARCH_MSM
 
+config MSM_DEBUG_UART
+        int
+        default 1 if MSM_DEBUG_UART1
+        default 2 if MSM_DEBUG_UART2
+        default 3 if MSM_DEBUG_UART3
+
+choice
+        prompt "Debug UART"
+
+        default MSM_DEBUG_UART_NONE
+
+        config MSM_DEBUG_UART_NONE
+                bool "None"
+
+        config MSM_DEBUG_UART1
+                bool "UART1"
+
+        config MSM_DEBUG_UART2
+                bool "UART2"
+
+        config MSM_DEBUG_UART3
+                bool "UART3"
+endchoice
+
 config MACH_HALIBUT
         depends on ARCH_MSM
         default y
diff --git a/arch/arm/mach-msm/include/mach/debug-macro.S b/arch/arm/mach-msm/include/mach/debug-macro.S
index 1db3c97dbc4..d48747ebcd3 100644
--- a/arch/arm/mach-msm/include/mach/debug-macro.S
+++ b/arch/arm/mach-msm/include/mach/debug-macro.S
@@ -14,15 +14,18 @@
  *
  */
 
+
+
 #include <mach/hardware.h>
 #include <mach/msm_iomap.h>
 
+#ifdef CONFIG_MSM_DEBUG_UART
         .macro  addruart,rx
         @ see if the MMU is enabled and select appropriate base address
         mrc     p15, 0, \rx, c1, c0
         tst     \rx, #1
-        ldreq   \rx, =MSM_UART1_PHYS
-        movne   \rx, #0
+        ldreq   \rx, =MSM_DEBUG_UART_PHYS
+        ldrne   \rx, =MSM_DEBUG_UART_BASE
         .endm
 
         .macro  senduart,rd,rx
@@ -32,13 +35,20 @@
 
         .macro  waituart,rd,rx
         @ wait for TX_READY
-        teq     \rx, #0
-        bne     2f
-1:      ldr     \rd, [\rx, #0x08]
+1001:   ldr     \rd, [\rx, #0x08]
         tst     \rd, #0x04
-        beq     1b
-2:
+        beq     1001b
+        .endm
+#else
+        .macro  addruart,rx
+        .endm
+
+        .macro  senduart,rd,rx
+        .endm
+
+        .macro  waituart,rd,rx
         .endm
+#endif
 
         .macro  busyuart,rd,rx
         .endm
diff --git a/arch/arm/mach-msm/include/mach/msm_iomap.h b/arch/arm/mach-msm/include/mach/msm_iomap.h
index 2f7b4c8620d..9dae1a98c77 100644
--- a/arch/arm/mach-msm/include/mach/msm_iomap.h
+++ b/arch/arm/mach-msm/include/mach/msm_iomap.h
@@ -84,6 +84,18 @@
 #define MSM_UART3_PHYS        0xA9C00000
 #define MSM_UART3_SIZE        SZ_4K
 
+#ifdef CONFIG_MSM_DEBUG_UART
+#define MSM_DEBUG_UART_BASE   0xE1000000
+#if CONFIG_MSM_DEBUG_UART == 1
+#define MSM_DEBUG_UART_PHYS   MSM_UART1_PHYS
+#elif CONFIG_MSM_DEBUG_UART == 2
+#define MSM_DEBUG_UART_PHYS   MSM_UART2_PHYS
+#elif CONFIG_MSM_DEBUG_UART == 3
+#define MSM_DEBUG_UART_PHYS   MSM_UART3_PHYS
+#endif
+#define MSM_DEBUG_UART_SIZE   SZ_4K
+#endif
+
 #define MSM_SDC1_PHYS         0xA0400000
 #define MSM_SDC1_SIZE         SZ_4K
 
diff --git a/arch/arm/mach-msm/include/mach/uncompress.h b/arch/arm/mach-msm/include/mach/uncompress.h
index 026e8955ace..d94292c29d8 100644
--- a/arch/arm/mach-msm/include/mach/uncompress.h
+++ b/arch/arm/mach-msm/include/mach/uncompress.h
@@ -16,9 +16,16 @@
 #ifndef __ASM_ARCH_MSM_UNCOMPRESS_H
 
 #include "hardware.h"
+#include "linux/io.h"
+#include "mach/msm_iomap.h"
 
 static void putc(int c)
 {
+#if defined(MSM_DEBUG_UART_PHYS)
+        unsigned base = MSM_DEBUG_UART_PHYS;
+        while (!(readl(base + 0x08) & 0x04)) ;
+        writel(c, base + 0x0c);
+#endif
 }
 
 static inline void flush(void)
diff --git a/arch/arm/mach-msm/io.c b/arch/arm/mach-msm/io.c
index 6e7692ff6f2..1c5e7dac086 100644
--- a/arch/arm/mach-msm/io.c
+++ b/arch/arm/mach-msm/io.c
@@ -42,6 +42,9 @@ static struct map_desc msm_io_desc[] __initdata = {
         MSM_DEVICE(GPIO1),
         MSM_DEVICE(GPIO2),
         MSM_DEVICE(CLK_CTL),
+#ifdef CONFIG_MSM_DEBUG_UART
+        MSM_DEVICE(DEBUG_UART),
+#endif
         {
                 .virtual =  (unsigned long) MSM_SHARED_RAM_BASE,
                 .pfn =      __phys_to_pfn(MSM_SHARED_RAM_PHYS),