[PATCH 1/1] arm: add debug_ll support

[Jean-Christophe PLAGNIOL-VILLARD]

Today we only use the DBGU port

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
---
 arch/arm/Kconfig                           |    1 +
 arch/arm/mach-at91/include/mach/debug_ll.h |   37 ++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)
 create mode 100644 arch/arm/mach-at91/include/mach/debug_ll.h

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 245bec8..a7f1bfb 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -25,6 +25,7 @@ config ARCH_AT91
 	bool "Atmel AT91"
 	select GENERIC_GPIO
 	select CLKDEV_LOOKUP
+	select HAS_DEBUG_LL
 
 config ARCH_EP93XX
 	bool "Cirrus Logic EP93xx"
diff --git a/arch/arm/mach-at91/include/mach/debug_ll.h b/arch/arm/mach-at91/include/mach/debug_ll.h
new file mode 100644
index 0000000..ee824cb
--- /dev/null
+++ b/arch/arm/mach-at91/include/mach/debug_ll.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2012
+ * Jean-Christophe PLAGNIOL-VILLARD <planioj at jcrosoft.com>
+ *
+ * Under GPLv2
+ */
+
+#ifndef __MACH_DEBUG_LL_H__
+#define __MACH_DEBUG_LL_H__
+
+#include <asm/io.h>
+#include <mach/hardware.h>
+
+#define UART_BASE	(AT91_BASE_SYS + AT91_DBGU)
+
+#define ATMEL_US_CSR		0x0014
+#define ATMEL_US_THR		0x001c
+#define ATMEL_US_TXRDY		(1 << 1)
+#define ATMEL_US_TXEMPTY	(1 << 9)
+
+/*
+ * The following code assumes the serial port has already been
+ * initialized by the bootloader.  If you didn't setup a port in
+ * your bootloader then nothing will appear (which might be desired).
+ *
+ * This does not append a newline
+ */
+static void putc(int c)
+{
+	while (!(__raw_readl(UART_BASE + ATMEL_US_CSR) & ATMEL_US_TXRDY))
+		barrier();
+	__raw_writel(c, UART_BASE + ATMEL_US_THR);
+
+	while (!(__raw_readl(UART_BASE + ATMEL_US_CSR) & ATMEL_US_TXEMPTY))
+		barrier();
+}
+#endif
-- 
1.7.10.4