[ARM] 4660/3: at91: allow selecting UART for early kernel messages

Currently early kernel messages, i.e., those from uncompression, go to the
debugging UART. And if it is enabled in the platform configuration, but
not initialized by the bootloader, the machine hangs, waiting for UART
status change. Besides, having those messages on another UART - typically
the console UART - may be preferrable. This patch allows selecting the
UART in kernel configuration.

Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Acked-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

9 files changed, 81 insertions, 11 deletions

diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index 5b0422cdde7..074dcd5d9a7 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -253,6 +253,36 @@ config AT91_TIMER_HZ
 	  system clock (of at least several MHz), rounding is less of a
 	  problem so it can be safer to use a decimal values like 100.
 
+choice
+	prompt "Select a UART for early kernel messages"
+
+config AT91_EARLY_DBGU
+	bool "DBGU"
+
+config AT91_EARLY_USART0
+	bool "USART0"
+
+config AT91_EARLY_USART1
+	bool "USART1"
+
+config AT91_EARLY_USART2
+	bool "USART2"
+	depends on ! ARCH_AT91X40
+
+config AT91_EARLY_USART3
+	bool "USART3"
+	depends on (ARCH_AT91RM9200 || ARCH_AT91SAM9RL || ARCH_AT91SAM9260)
+
+config AT91_EARLY_USART4
+	bool "USART4"
+	depends on ARCH_AT91SAM9260
+
+config AT91_EARLY_USART5
+	bool "USART5"
+	depends on ARCH_AT91SAM9260
+
+endchoice
+
 endmenu
 
 endif
diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c
index 111da57f533..60f52904aad 100644
--- a/drivers/serial/atmel_serial.c
+++ b/drivers/serial/atmel_serial.c
@@ -34,6 +34,7 @@
 #include <linux/tty_flip.h>
 #include <linux/platform_device.h>
 #include <linux/atmel_pdc.h>
+#include <linux/atmel_serial.h>
 
 #include <asm/io.h>
 
@@ -45,8 +46,6 @@
 #include <asm/arch/gpio.h>
 #endif
 
-#include "atmel_serial.h"
-
 #if defined(CONFIG_SERIAL_ATMEL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
 #define SUPPORT_SYSRQ
 #endif
diff --git a/include/asm-arm/arch-at91/at91rm9200.h b/include/asm-arm/arch-at91/at91rm9200.h
index 802891a9cd8..e8fc0b1c33f 100644
--- a/include/asm-arm/arch-at91/at91rm9200.h
+++ b/include/asm-arm/arch-at91/at91rm9200.h
@@ -93,6 +93,11 @@
 #define AT91_RTC	(0xfffffe00 - AT91_BASE_SYS)	/* Real-Time Clock */
 #define AT91_MC		(0xffffff00 - AT91_BASE_SYS)	/* Memory Controllers */
 
+#define AT91_USART0	AT91RM9200_BASE_US0
+#define AT91_USART1	AT91RM9200_BASE_US1
+#define AT91_USART2	AT91RM9200_BASE_US2
+#define AT91_USART3	AT91RM9200_BASE_US3
+
 #define AT91_MATRIX	0	/* not supported */
 
 /*
diff --git a/include/asm-arm/arch-at91/at91sam9260.h b/include/asm-arm/arch-at91/at91sam9260.h
index 0427f8698c0..c8934fe34dc 100644
--- a/include/asm-arm/arch-at91/at91sam9260.h
+++ b/include/asm-arm/arch-at91/at91sam9260.h
@@ -99,6 +99,13 @@
 #define AT91_WDT	(0xfffffd40 - AT91_BASE_SYS)
 #define AT91_GPBR	(0xfffffd50 - AT91_BASE_SYS)
 
+#define AT91_USART0	AT91SAM9260_BASE_US0
+#define AT91_USART1	AT91SAM9260_BASE_US1
+#define AT91_USART2	AT91SAM9260_BASE_US2
+#define AT91_USART3	AT91SAM9260_BASE_US3
+#define AT91_USART4	AT91SAM9260_BASE_US4
+#define AT91_USART5	AT91SAM9260_BASE_US5
+
 
 /*
  * Internal Memory.
diff --git a/include/asm-arm/arch-at91/at91sam9261.h b/include/asm-arm/arch-at91/at91sam9261.h
index 9eb45957033..c7c4778dac4 100644
--- a/include/asm-arm/arch-at91/at91sam9261.h
+++ b/include/asm-arm/arch-at91/at91sam9261.h
@@ -84,6 +84,10 @@
 #define AT91_WDT	(0xfffffd40 - AT91_BASE_SYS)
 #define AT91_GPBR	(0xfffffd50 - AT91_BASE_SYS)
 
+#define AT91_USART0	AT91SAM9261_BASE_US0
+#define AT91_USART1	AT91SAM9261_BASE_US1
+#define AT91_USART2	AT91SAM9261_BASE_US2
+
 
 /*
  * Internal Memory.
diff --git a/include/asm-arm/arch-at91/at91sam9263.h b/include/asm-arm/arch-at91/at91sam9263.h
index 115c47ac7eb..018a647311d 100644
--- a/include/asm-arm/arch-at91/at91sam9263.h
+++ b/include/asm-arm/arch-at91/at91sam9263.h
@@ -101,6 +101,10 @@
 #define AT91_RTT1	(0xfffffd50 - AT91_BASE_SYS)
 #define AT91_GPBR	(0xfffffd60 - AT91_BASE_SYS)
 
+#define AT91_USART0	AT91SAM9263_BASE_US0
+#define AT91_USART1	AT91SAM9263_BASE_US1
+#define AT91_USART2	AT91SAM9263_BASE_US2
+
 #define AT91_SMC	AT91_SMC0
 
 /*
diff --git a/include/asm-arm/arch-at91/at91sam9rl.h b/include/asm-arm/arch-at91/at91sam9rl.h
index 8a9708a370c..16d2832f6c0 100644
--- a/include/asm-arm/arch-at91/at91sam9rl.h
+++ b/include/asm-arm/arch-at91/at91sam9rl.h
@@ -94,6 +94,11 @@
 #define AT91_GPBR	(0xfffffd60 - AT91_BASE_SYS)
 #define AT91_RTC	(0xfffffe00 - AT91_BASE_SYS)
 
+#define AT91_USART0	AT91SAM9RL_BASE_US0
+#define AT91_USART1	AT91SAM9RL_BASE_US1
+#define AT91_USART2	AT91SAM9RL_BASE_US2
+#define AT91_USART3	AT91SAM9RL_BASE_US3
+
 
 /*
  * Internal Memory.
diff --git a/include/asm-arm/arch-at91/uncompress.h b/include/asm-arm/arch-at91/uncompress.h
index 272a7e0dc6c..f5636a8f613 100644
--- a/include/asm-arm/arch-at91/uncompress.h
+++ b/include/asm-arm/arch-at91/uncompress.h
@@ -22,7 +22,23 @@
 #define __ASM_ARCH_UNCOMPRESS_H
 
 #include <asm/io.h>
-#include <asm/arch/at91_dbgu.h>
+#include <linux/atmel_serial.h>
+
+#if defined(CONFIG_AT91_EARLY_DBGU)
+#define UART_OFFSET (AT91_DBGU + AT91_BASE_SYS)
+#elif defined(CONFIG_AT91_EARLY_USART0)
+#define UART_OFFSET AT91_USART0
+#elif defined(CONFIG_AT91_EARLY_USART1)
+#define UART_OFFSET AT91_USART1
+#elif defined(CONFIG_AT91_EARLY_USART2)
+#define UART_OFFSET AT91_USART2
+#elif defined(CONFIG_AT91_EARLY_USART3)
+#define UART_OFFSET AT91_USART3
+#elif defined(CONFIG_AT91_EARLY_USART4)
+#define UART_OFFSET AT91_USART4
+#elif defined(CONFIG_AT91_EARLY_USART5)
+#define UART_OFFSET AT91_USART5
+#endif
 
 /*
  * The following code assumes the serial port has already been
@@ -33,22 +49,22 @@
  */
 static void putc(int c)
 {
-#ifdef AT91_DBGU
-	void __iomem *sys = (void __iomem *) AT91_BASE_SYS;	/* physical address */
+#ifdef UART_OFFSET
+	void __iomem *sys = (void __iomem *) UART_OFFSET;	/* physical address */
 
-	while (!(__raw_readl(sys + AT91_DBGU_SR) & AT91_DBGU_TXRDY))
+	while (!(__raw_readl(sys + ATMEL_US_CSR) & ATMEL_US_TXRDY))
 		barrier();
-	__raw_writel(c, sys + AT91_DBGU_THR);
+	__raw_writel(c, sys + ATMEL_US_THR);
 #endif
 }
 
 static inline void flush(void)
 {
-#ifdef AT91_DBGU
-	void __iomem *sys = (void __iomem *) AT91_BASE_SYS;	/* physical address */
+#ifdef UART_OFFSET
+	void __iomem *sys = (void __iomem *) UART_OFFSET;	/* physical address */
 
 	/* wait for transmission to complete */
-	while (!(__raw_readl(sys + AT91_DBGU_SR) & AT91_DBGU_TXEMPTY))
+	while (!(__raw_readl(sys + ATMEL_US_CSR) & ATMEL_US_TXEMPTY))
 		barrier();
 #endif
 }
diff --git a/drivers/serial/atmel_serial.h b/include/linux/atmel_serial.h
index e0141776517..fd6833764d7 100644
--- a/drivers/serial/atmel_serial.h
+++ b/include/linux/atmel_serial.h
@@ -1,5 +1,5 @@
 /*
- * drivers/serial/atmel_serial.h
+ * include/linux/atmel_serial.h
  *
  * Copyright (C) 2005 Ivan Kokshaysky
  * Copyright (C) SAN People