8 files changed, 103 insertions, 0 deletions
diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index f6846ad5d3a8..30adc7875daa 100644
--- a/arch/metag/Kconfig
+++ b/arch/metag/Kconfig
@@ -214,6 +214,18 @@ config METAG_PERFCOUNTER_IRQS
 	  When disabled, Performance Counters information will be collected
 	  based on Timer Interrupt.
 
+config METAG_DA
+	bool "DA support"
+	help
+	  Say Y if you plan to use a DA debug adapter with Linux. The presence
+	  of the DA will be detected automatically at boot, so it is safe to say
+	  Y to this option even when booting without a DA.
+
+	  This enables support for services provided by DA JTAG debug adapters,
+	  such as:
+	  - communication over DA channels (such as the console driver).
+	  - use of the DA filesystem.
+
 menu "Boot options"
 
 config METAG_BUILTIN_DTB
diff --git a/arch/metag/configs/meta1_defconfig b/arch/metag/configs/meta1_defconfig
index 837c235ab67a..ad663ca53208 100644
--- a/arch/metag/configs/meta1_defconfig
+++ b/arch/metag/configs/meta1_defconfig
@@ -14,6 +14,7 @@ CONFIG_PARTITION_ADVANCED=y
 # CONFIG_IOSCHED_CFQ is not set
 CONFIG_FLATMEM_MANUAL=y
 CONFIG_META12_FPGA=y
+CONFIG_METAG_DA=y
 CONFIG_HZ_100=y
 CONFIG_DEVTMPFS=y
 CONFIG_DEVTMPFS_MOUNT=y
@@ -27,6 +28,8 @@ CONFIG_BLK_DEV_RAM_SIZE=16384
 # CONFIG_SERIO is not set
 # CONFIG_VT is not set
 # CONFIG_LEGACY_PTYS is not set
+CONFIG_DA_TTY=y
+CONFIG_DA_CONSOLE=y
 # CONFIG_DEVKMEM is not set
 # CONFIG_HW_RANDOM is not set
 # CONFIG_HWMON is not set
diff --git a/arch/metag/configs/meta2_defconfig b/arch/metag/configs/meta2_defconfig
index e5bada83dd76..47922e9306af 100644
--- a/arch/metag/configs/meta2_defconfig
+++ b/arch/metag/configs/meta2_defconfig
@@ -16,6 +16,7 @@ CONFIG_PARTITION_ADVANCED=y
 CONFIG_METAG_L2C=y
 CONFIG_FLATMEM_MANUAL=y
 CONFIG_METAG_HALT_ON_PANIC=y
+CONFIG_METAG_DA=y
 CONFIG_HZ_100=y
 CONFIG_DEVTMPFS=y
 # CONFIG_STANDALONE is not set
@@ -28,6 +29,8 @@ CONFIG_BLK_DEV_RAM_SIZE=16384
 # CONFIG_SERIO is not set
 # CONFIG_VT is not set
 # CONFIG_LEGACY_PTYS is not set
+CONFIG_DA_TTY=y
+CONFIG_DA_CONSOLE=y
 # CONFIG_DEVKMEM is not set
 # CONFIG_HW_RANDOM is not set
 # CONFIG_HWMON is not set
diff --git a/arch/metag/configs/meta2_smp_defconfig b/arch/metag/configs/meta2_smp_defconfig
index 41983a20db72..f5082505872d 100644
--- a/arch/metag/configs/meta2_smp_defconfig
+++ b/arch/metag/configs/meta2_smp_defconfig
@@ -17,6 +17,7 @@ CONFIG_METAG_L2C=y
 CONFIG_FLATMEM_MANUAL=y
 CONFIG_METAG_HALT_ON_PANIC=y
 CONFIG_SMP=y
+CONFIG_METAG_DA=y
 CONFIG_HZ_100=y
 CONFIG_DEVTMPFS=y
 # CONFIG_STANDALONE is not set
@@ -29,6 +30,8 @@ CONFIG_BLK_DEV_RAM_SIZE=16384
 # CONFIG_SERIO is not set
 # CONFIG_VT is not set
 # CONFIG_LEGACY_PTYS is not set
+CONFIG_DA_TTY=y
+CONFIG_DA_CONSOLE=y
 # CONFIG_DEVKMEM is not set
 # CONFIG_HW_RANDOM is not set
 # CONFIG_HWMON is not set
diff --git a/arch/metag/include/asm/da.h b/arch/metag/include/asm/da.h
new file mode 100644
index 000000000000..81bd5212fb03
--- /dev/null
+++ b/arch/metag/include/asm/da.h
@@ -0,0 +1,43 @@
+/*
+ * Meta DA JTAG debugger control.
+ *
+ * Copyright 2012 Imagination Technologies Ltd.
+ */
+
+#ifndef _METAG_DA_H_
+#define _METAG_DA_H_
+
+#ifdef CONFIG_METAG_DA
+
+#include <linux/init.h>
+#include <linux/types.h>
+
+extern bool _metag_da_present;
+
+/**
+ * metag_da_enabled() - Find whether a DA is currently enabled.
+ *
+ * Returns:	true if a DA was detected, false if not.
+ */
+static inline bool metag_da_enabled(void)
+{
+	return _metag_da_present;
+}
+
+/**
+ * metag_da_probe() - Try and detect a connected DA.
+ *
+ * This is used at start up to detect whether a DA is active.
+ *
+ * Returns:	0 on detection, -err otherwise.
+ */
+int __init metag_da_probe(void);
+
+#else /* !CONFIG_METAG_DA */
+
+#define metag_da_enabled() false
+#define metag_da_probe() do {} while (0)
+
+#endif
+
+#endif /* _METAG_DA_H_ */
diff --git a/arch/metag/kernel/Makefile b/arch/metag/kernel/Makefile
index a5e4ba6fd20a..d7675f4a5df8 100644
--- a/arch/metag/kernel/Makefile
+++ b/arch/metag/kernel/Makefile
@@ -28,6 +28,7 @@ obj-y	+= user_gateway.o
 obj-$(CONFIG_PERF_EVENTS)		+= perf/
 
 obj-$(CONFIG_METAG_COREMEM)		+= coremem.o
+obj-$(CONFIG_METAG_DA)			+= da.o
 obj-$(CONFIG_DYNAMIC_FTRACE)		+= ftrace.o
 obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace_stub.o
 obj-$(CONFIG_MODULES)			+= metag_ksyms.o
diff --git a/arch/metag/kernel/da.c b/arch/metag/kernel/da.c
new file mode 100644
index 000000000000..52aabb658fde
--- /dev/null
+++ b/arch/metag/kernel/da.c
@@ -0,0 +1,23 @@
+/*
+ * Meta DA JTAG debugger control.
+ *
+ * Copyright 2012 Imagination Technologies Ltd.
+ */
+
+
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <asm/da.h>
+#include <asm/metag_mem.h>
+
+bool _metag_da_present;
+
+int __init metag_da_probe(void)
+{
+	_metag_da_present = (metag_in32(T0VECINT_BHALT) == 1);
+	if (_metag_da_present)
+		pr_info("DA present\n");
+	else
+		pr_info("DA not present\n");
+	return 0;
+}
diff --git a/arch/metag/kernel/setup.c b/arch/metag/kernel/setup.c
index 74e2c1f812a5..89f9cdc389e8 100644
--- a/arch/metag/kernel/setup.c
+++ b/arch/metag/kernel/setup.c
@@ -37,6 +37,7 @@
 #include <asm/hwthread.h>
 #include <asm/mmzone.h>
 #include <asm/l2cache.h>
+#include <asm/da.h>
 #include <asm/prom.h>
 #include <asm/mach/arch.h>
 #include <asm/core_reg.h>
@@ -60,6 +61,11 @@ extern char _heap_start[];
 extern u32 __dtb_start[];
 #endif
 
+#ifdef CONFIG_DA_CONSOLE
+/* Our early channel based console driver */
+extern struct console dash_console;
+#endif
+
 struct machine_desc *machine_desc __initdata;
 
 /*
@@ -180,6 +186,15 @@ void __init setup_arch(char **cmdline_p)
 
 	metag_cache_probe();
 
+	metag_da_probe();
+#ifdef CONFIG_DA_CONSOLE
+	if (metag_da_enabled()) {
+		/* An early channel based console driver */
+		register_console(&dash_console);
+		add_preferred_console("ttyDA", 1, NULL);
+	}
+#endif
+
 	/* try interpreting the argument as a device tree */
 	machine_desc = setup_machine_fdt(original_cmd_line);
 	/* if it doesn't look like a device tree it must be a command line */