[PATCH 1/2] of/lib: Allow scripts/dtc/libfdt to be used from kernel code

[ddaney.cavm at gmail.com]

From: David Daney <david.daney at cavium.com>

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 at cavium.com>
---
 include/linux/libfdt.h     |    8 ++++++++
 include/linux/libfdt_env.h |   13 +++++++++++++
 lib/Kconfig                |    6 ++++++
 lib/Makefile               |    5 +++++
 lib/fdt.c                  |    2 ++
 lib/fdt_ro.c               |    2 ++
 lib/fdt_rw.c               |    2 ++
 lib/fdt_strerror.c         |    2 ++
 lib/fdt_sw.c               |    2 ++
 lib/fdt_wip.c              |    2 ++
 10 files changed, 44 insertions(+), 0 deletions(-)
 create mode 100644 include/linux/libfdt.h
 create mode 100644 include/linux/libfdt_env.h
 create mode 100644 lib/fdt.c
 create mode 100644 lib/fdt_ro.c
 create mode 100644 lib/fdt_rw.c
 create mode 100644 lib/fdt_strerror.c
 create mode 100644 lib/fdt_sw.c
 create mode 100644 lib/fdt_wip.c

diff --git a/include/linux/libfdt.h b/include/linux/libfdt.h
new file mode 100644
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
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 32f3e5a..48d55b4 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -276,4 +276,10 @@ config CORDIC
 	  so its calculations are in fixed point. Modules can select this
 	  when they require this function. Module will be called cordic.
 
+#
+# libfdt files, only selected if needed.
+#
+config LIBFDT
+	bool
+
 endmenu
diff --git a/lib/Makefile b/lib/Makefile
index a4da283..f5254d2 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -115,6 +115,11 @@ obj-$(CONFIG_CPU_RMAP) += cpu_rmap.o
 
 obj-$(CONFIG_CORDIC) += cordic.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
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
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
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
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
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
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"
-- 
1.7.2.3