of/lib: Allow scripts/dtc/libfdt to be used from kernel code

libfdt is part of the device tree support in scripts/dtc/libfdt.  For
some platforms that use the Device Tree, we want to be able to edit
the flattened device tree form.

We don't want to burden kernel builds that do not require it, so we
gate compilation of libfdt files with CONFIG_LIBFDT.  So if it is
needed, you need to do this in your Kconfig:

	select LIBFDT

And in the Makefile of the code using libfdt something like:

ccflags-y := -I$(src)/../../../scripts/dtc/libfdt

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: linux-kernel@vger.kernel.org
Acked-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/include/linux/libfdt.h b/include/linux/libfdt.h
new file mode 100644 (file)
index 0000000..4c0306c
--- /dev/null
+++ b/include/linux/libfdt.h
@@ -0,0 +1,8 @@
+#ifndef _INCLUDE_LIBFDT_H_
+#define _INCLUDE_LIBFDT_H_
+
+#include <linux/libfdt_env.h>
+#include "../../scripts/dtc/libfdt/fdt.h"
+#include "../../scripts/dtc/libfdt/libfdt.h"
+
+#endif /* _INCLUDE_LIBFDT_H_ */

diff --git a/include/linux/libfdt_env.h b/include/linux/libfdt_env.h
new file mode 100644 (file)
index 0000000..01508c7
--- /dev/null
+++ b/include/linux/libfdt_env.h
@@ -0,0 +1,13 @@
+#ifndef _LIBFDT_ENV_H
+#define _LIBFDT_ENV_H
+
+#include <linux/string.h>
+
+#include <asm/byteorder.h>
+
+#define fdt32_to_cpu(x) be32_to_cpu(x)
+#define cpu_to_fdt32(x) cpu_to_be32(x)
+#define fdt64_to_cpu(x) be64_to_cpu(x)
+#define cpu_to_fdt64(x) cpu_to_be64(x)
+
+#endif /* _LIBFDT_ENV_H */

diff --git a/lib/Kconfig b/lib/Kconfig
index a9e15403434ef9adcec951800048752b8cbb1275..e091300b2045bab9319ca99f82062af8a354129d 100644 (file)
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -395,4 +395,10 @@ config SIGNATURE
          Digital signature verification. Currently only RSA is supported.
          Implementation is done using GnuPG MPI library
 
+#
+# libfdt files, only selected if needed.
+#
+config LIBFDT
+       bool
+
 endmenu

diff --git a/lib/Makefile b/lib/Makefile
index 8c31a0cb75e97746af1cd02906ac149105250cc2..2f2be5a8734c4ebf7ad21dbf79c3072df2e99f53 100644 (file)
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -130,6 +130,11 @@ obj-$(CONFIG_GENERIC_STRNLEN_USER) += strnlen_user.o
 
 obj-$(CONFIG_STMP_DEVICE) += stmp_device.o
 
+libfdt_files = fdt.o fdt_ro.o fdt_wip.o fdt_rw.o fdt_sw.o fdt_strerror.o
+$(foreach file, $(libfdt_files), \
+       $(eval CFLAGS_$(file) = -I$(src)/../scripts/dtc/libfdt))
+lib-$(CONFIG_LIBFDT) += $(libfdt_files)
+
 hostprogs-y    := gen_crc32table
 clean-files    := crc32table.h
 

diff --git a/lib/fdt.c b/lib/fdt.c
new file mode 100644 (file)
index 0000000..97f2006
--- /dev/null
+++ b/lib/fdt.c
@@ -0,0 +1,2 @@
+#include <linux/libfdt_env.h>
+#include "../scripts/dtc/libfdt/fdt.c"

diff --git a/lib/fdt_ro.c b/lib/fdt_ro.c
new file mode 100644 (file)
index 0000000..f73c04e
--- /dev/null
+++ b/lib/fdt_ro.c
@@ -0,0 +1,2 @@
+#include <linux/libfdt_env.h>
+#include "../scripts/dtc/libfdt/fdt_ro.c"

diff --git a/lib/fdt_rw.c b/lib/fdt_rw.c
new file mode 100644 (file)
index 0000000..0c1f0f4
--- /dev/null
+++ b/lib/fdt_rw.c
@@ -0,0 +1,2 @@
+#include <linux/libfdt_env.h>
+#include "../scripts/dtc/libfdt/fdt_rw.c"

diff --git a/lib/fdt_strerror.c b/lib/fdt_strerror.c
new file mode 100644 (file)
index 0000000..8713e3f
--- /dev/null
+++ b/lib/fdt_strerror.c
@@ -0,0 +1,2 @@
+#include <linux/libfdt_env.h>
+#include "../scripts/dtc/libfdt/fdt_strerror.c"

diff --git a/lib/fdt_sw.c b/lib/fdt_sw.c
new file mode 100644 (file)
index 0000000..9ac7e50
--- /dev/null
+++ b/lib/fdt_sw.c
@@ -0,0 +1,2 @@
+#include <linux/libfdt_env.h>
+#include "../scripts/dtc/libfdt/fdt_sw.c"

diff --git a/lib/fdt_wip.c b/lib/fdt_wip.c
new file mode 100644 (file)
index 0000000..45b3fc3
--- /dev/null
+++ b/lib/fdt_wip.c
@@ -0,0 +1,2 @@
+#include <linux/libfdt_env.h>
+#include "../scripts/dtc/libfdt/fdt_wip.c"