[PATCH 1/3] edid-decode: Introduce libedid-decode wrapper

[Shashank Sharma <contactshashanksharma@xxxxxxxxx>]

From: Shashank Sharma <shashank.sharma@xxxxxxx>

This patch does some small changes to make the core logic of
edid-decode tool available to a shared library wrapper. With
these changes, the EDID's 'state' variable will be avialble
to another process via some library API calls.

Cc: Pekka Paalanen <ppaalanen@xxxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxx>

Signed-off-by: Shashank Sharma <contactshashanksharma@xxxxxxxxx>
---
 Makefile        | 22 +++++++++++++++++++++-
 edid-decode.cpp | 15 ++++++++++++++-
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 1843700..ebf3370 100644
--- a/Makefile
+++ b/Makefile
@@ -1,14 +1,20 @@
 ifeq ($(OS),Windows_NT)
 	bindir ?= /usr/bin
 	mandir ?= /usr/share/man
+	libdir ?= /usr/lib
+	includedir ?= /usr/include
 else
 	UNAME_S := $(shell uname -s)
 	ifeq ($(UNAME_S),Darwin)
 		bindir ?= /usr/local/sbin
 		mandir ?= /usr/local/share/man
+		libdir ?= /usr/local/lib
+		includedir ?= /usr/include
 	else
 		bindir ?= /usr/bin
 		mandir ?= /usr/share/man
+		libdir ?= /usr/lib
+		includedir ?= /usr/include
 	endif
 endif
 
@@ -19,6 +25,11 @@ SOURCES = edid-decode.cpp parse-base-block.cpp parse-cta-block.cpp \
 	  parse-di-ext-block.cpp parse-vtb-ext-block.cpp calc-gtf-cvt.cpp
 WARN_FLAGS = -Wall -Wextra -Wno-missing-field-initializers -Wno-unused-parameter -Wimplicit-fallthrough
 
+LIB_NAME = libedid-decode.so
+LIB_FLAGS = -fPIC
+LIBLINK_FLAGS = -shared
+LIB_SOURCES = libedid-decode-api.cpp
+
 all: edid-decode
 
 sha = -DSHA=$(shell if test -d .git ; then git rev-parse --short=12 HEAD ; fi)
@@ -30,11 +41,20 @@ edid-decode: $(SOURCES) edid-decode.h oui.h Makefile
 edid-decode.js: $(SOURCES) edid-decode.h oui.h Makefile
 	$(EMXX) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) $(WARN_FLAGS) $(sha) $(date) -s EXPORTED_FUNCTIONS='["_parse_edid"]' -s EXTRA_EXPORTED_RUNTIME_METHODS='["ccall", "cwrap"]' -o $@ $(SOURCES) -lm
 
+libedid-decode: $(SOURCES) edid-decode.h oui.h Makefile
+	$(CXX) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) $(WARN_FLAGS) -g $(LIB_FLAGS) $(sha) $(date) $(LIBLINK_FLAGS) -o $(LIB_NAME) $(LIB_SOURCES) $(SOURCES) -lm
+
 clean:
-	rm -f edid-decode
+	rm -f edid-decode libedid-decode.so
 
 install:
 	mkdir -p $(DESTDIR)$(bindir)
 	install -m 0755 edid-decode $(DESTDIR)$(bindir)
 	mkdir -p $(DESTDIR)$(mandir)/man1
 	install -m 0644 edid-decode.1 $(DESTDIR)$(mandir)/man1
+
+install-lib:
+	mkdir -p $(DESTDIR)$(libdir)
+	mkdir -p $(DESTDIR)$(includedir)
+	install -m 0755 libedid-decode.so $(DESTDIR)$(libdir)
+	install -m 0644 libedid-decode-api.h $(DESTDIR)$(includedir)
diff --git a/edid-decode.cpp b/edid-decode.cpp
index 4a90aba..babff4a 100644
--- a/edid-decode.cpp
+++ b/edid-decode.cpp
@@ -21,7 +21,7 @@
 #define STR(x) #x
 #define STRING(x) STR(x)
 
-static edid_state state;
+edid_state state;
 
 static unsigned char edid[EDID_PAGE_SIZE * EDID_MAX_BLOCKS];
 static bool odd_hex_digits;
@@ -1012,6 +1012,19 @@ static bool extract_edid(int fd, FILE *error)
 	state.edid_size = edid_data.size();
 	return true;
 }
+struct edid_state *extract_edid_state(int fd, FILE *error)
+{
+	bool ret;
+
+	ret = extract_edid(fd, error);
+	if (ret) {
+		/* update the number of blocks */
+		state.num_blocks = state.edid_size / EDID_PAGE_SIZE;
+		return &state;
+	}
+
+	return NULL;
+}
 
 static unsigned char crc_calc(const unsigned char *b)
 {
-- 
2.32.0