libgpiod: add package for library and tools

libgpiod is a C library with corresponding tools for interacting
with the linux GPIO character device (gpiod stands for GPIO device).

Since linux 4.8 the GPIO sysfs interface is deprecated. User space should use
the character device instead. This library encapsulates the ioctl calls and
data structures behind a straightforward API.

Signed-off-by: Michael Heimpold <mhei@heimpold.de>

libs/libgpiod/Makefile

@@ -0,0 +1,79 @@
+#
+# Copyright (C) 2018 Michael Heimpold <mhei@heimpold.de>
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=libgpiod
+PKG_VERSION:=1.0
+PKG_RELEASE:=1
+
+PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
+PKG_SOURCE_URL:=@KERNEL/software/libs/libgpiod/
+PKG_HASH:=34c76b3730b9d4a1159bcb14000f78b1e890251b8a3823b794fa930654eabdd0
+
+PKG_LICENSE:=LGPL-2.1+
+PKG_LICENSE_FILES:=COPYING
+
+PKG_MAINTAINER:=Michael Heimpold <mhei@heimpold.de>
+
+PKG_INSTALL:=1
+PKG_BUILD_PARALLEL:=1
+
+include $(INCLUDE_DIR)/package.mk
+
+ifneq ($(CONFIG_PACKAGE_gpiod-tools),)
+CONFIGURE_ARGS += --enable-tools
+endif
+
+define Package/libgpiod
+  SECTION:=libs
+  CATEGORY:=Libraries
+  URL:=https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git
+  TITLE:=Library for interacting with Linux's GPIO character device
+  DEPENDS:=@GPIO_SUPPORT
+endef
+
+define Package/libgpiod/description
+  C library for interacting with the linux GPIO character device
+  (gpiod stands for GPIO device).
+endef
+
+define Package/gpiod-tools
+  SECTION:=utils
+  CATEGORY:=Utilities
+  TITLE:=Tools for interacting with GPIO pins
+  DEPENDS:=+libgpiod
+endef
+
+define Package/gpiod-tools/description
+  Tools for interacting with the linux GPIO character device
+  (gpiod stands for GPIO device).
+endef
+
+define Build/InstallDev
+	$(INSTALL_DIR) $(1)/usr/include
+	$(CP) $(PKG_INSTALL_DIR)/usr/include/gpiod.h $(1)/usr/include/
+
+	$(INSTALL_DIR) $(1)/usr/lib
+	$(CP) $(PKG_INSTALL_DIR)/usr/lib/libgpiod.{so*,a} $(1)/usr/lib/
+
+	$(INSTALL_DIR) $(1)/usr/lib/pkgconfig
+	$(CP) $(PKG_INSTALL_DIR)/usr/lib/pkgconfig/libgpiod.pc $(1)/usr/lib/pkgconfig/
+endef
+
+define Package/libgpiod/install
+	$(INSTALL_DIR) $(1)/usr/lib
+	$(CP) $(PKG_INSTALL_DIR)/usr/lib/libgpiod.so* $(1)/usr/lib/
+endef
+
+define Package/gpiod-tools/install
+	$(INSTALL_DIR) $(1)/usr/bin
+	$(CP) $(PKG_INSTALL_DIR)/usr/bin/* $(1)/usr/bin/
+endef
+
+$(eval $(call BuildPackage,libgpiod))
+$(eval $(call BuildPackage,gpiod-tools))