metag: Add JTAG Debug Adapter (DA) support

Add basic JTAG Debug Adapter (DA) support so that drivers which
communicate with the DA can detect whether one is actually present
(otherwise the target will halt indefinitely).

This allows the metag_da TTY driver and imgdafs filesystem driver to be
built, updates defconfigs, and sets up the metag_da console early if
it's configured in.

Signed-off-by: James Hogan <james.hogan@imgtec.com>

diff --git a/MAINTAINERS b/MAINTAINERS
index 9b2b7699da4df128b5a40277fc4e53dcfafd8fe3..a6a0c352e5599c4858d950fd8a98ec752ed08304 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5042,6 +5042,8 @@ F:        Documentation/devicetree/bindings/metag/
 F:     drivers/clocksource/metag_generic.c
 F:     drivers/irqchip/irq-metag.c
 F:     drivers/irqchip/irq-metag-ext.c
+F:     drivers/tty/metag_da.c
+F:     fs/imgdafs/
 
 MICROBLAZE ARCHITECTURE
 M:     Michal Simek <monstr@monstr.eu>

diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index f6846ad5d3a8dd80a92b6e47c1fb09e7c201445c..30adc7875daa133b0d8599a46fbced46d93a623d 100644 (file)
--- 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 837c235ab67a41908c9e32d7fde65daa8b60ece6..ad663ca5320823e4bbcddc4f8fc8eb26cf85b724 100644 (file)
--- 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 e5bada83dd769b576d36f361f1e9499e39aec55e..47922e9306af29739e4ad148ec595dd2ceb0bd52 100644 (file)
--- 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 41983a20db727f6922e577d2ed4f9a17f5738357..f5082505872d7a2e533235d2d58f25d466a48c81 100644 (file)
--- 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 (file)
index 0000000..81bd521
--- /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 a5e4ba6fd20a48fcc761d745d1caf67b77a786d2..d7675f4a5df83a1471ea2994eafd3001058cf554 100644 (file)
--- 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 (file)
index 0000000..52aabb6
--- /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 74e2c1f812a5a356cfd67d225daf7a191588e492..89f9cdc389e8094a771a13600a7ec8abe5317664 100644 (file)
--- 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 */