rockchip: video: introduce VIDEO_DW_HDMI and select for Rockchip HDMI

Instead of having drivers/video/rockchip/Kconfig point outside of its
hierarchy for dw_hdmi.o, we should use a configuration-option to
include the Designware HDMI support.

This change introduces a new config option (not to be selected via
menuconfig, but to be selected from a dependent video driver's
configuration option) that enables dw_hdmi.o and selects it whenever
the HDMI support for Rockchip SoCs is selected.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/video/Kconfig

@@ -619,4 +619,13 @@ config LCD
 	  CONFIG option. See the README for details. Drives which have been
 	  converted to driver model will instead used CONFIG_DM_VIDEO.
 
+config VIDEO_DW_HDMI
+	bool
+	help
+	  Enables the common driver code for the Designware HDMI TX
+	  block found in SoCs from various vendors.
+	  As this does not provide any functionality by itself (but
+	  rather requires a SoC-specific glue driver to call it), it
+	  can not be enabled from the configuration menu.
+
 endmenu

drivers/video/Makefile

@@ -57,6 +57,7 @@ obj-$(CONFIG_VIDEO_VESA) += vesa.o
 obj-$(CONFIG_FORMIKE) += formike.o
 obj-$(CONFIG_LG4573) += lg4573.o
 obj-$(CONFIG_AM335X_LCD) += am335x-fb.o
+obj-$(CONFIG_VIDEO_DW_HDMI) += dw_hdmi.o
 
 obj-${CONFIG_VIDEO_TEGRA124} += tegra124/
 obj-${CONFIG_EXYNOS_FB} += exynos/

drivers/video/rockchip/Kconfig

@@ -35,6 +35,7 @@ config DISPLAY_ROCKCHIP_LVDS
 
 config DISPLAY_ROCKCHIP_HDMI
 	bool "HDMI port"
+	select VIDEO_DW_HDMI
 	depends on VIDEO_ROCKCHIP
 	help
 	  This enables High-Definition Multimedia Interface display support.

drivers/video/rockchip/Makefile

@@ -9,6 +9,6 @@ ifdef CONFIG_VIDEO_ROCKCHIP
 obj-y += rk_vop.o
 obj-$(CONFIG_DISPLAY_ROCKCHIP_EDP) += rk_edp.o
 obj-$(CONFIG_DISPLAY_ROCKCHIP_LVDS) += rk_lvds.o
-obj-$(CONFIG_DISPLAY_ROCKCHIP_HDMI) += rk_hdmi.o ../dw_hdmi.o
+obj-$(CONFIG_DISPLAY_ROCKCHIP_HDMI) += rk_hdmi.o
 obj-$(CONFIG_DISPLAY_ROCKCHIP_MIPI) += rk_mipi.o
 endif