drm: add support for DisplayPort CEC-Tunneling-over-AUX

This adds support for the DisplayPort CEC-Tunneling-over-AUX feature that is part of the DisplayPort 1.3 standard. Unfortunately, not all DisplayPort/USB-C to HDMI adapters with a chip that has this capability actually hook up the CEC pin, so even though a CEC device is created, it may not actually work. Signed-off-by: Hans Verkuil <[email protected]> Reviewed-by: Ville Syrjälä <[email protected]> Signed-off-by: Ville Syrjälä <[email protected]> Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Rust-for-Linux · Jul 13, 2018 · 2c6d1ff · 2c6d1ff
1 parent cf19fa2
commit 2c6d1ff
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diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
@@ -122,6 +122,16 @@ config DRM_LOAD_EDID_FIRMWARE
 	  default case is N. Details and instructions how to build your own
 	  EDID data are given in Documentation/EDID/HOWTO.txt.
 
+config DRM_DP_CEC
+	bool "Enable DisplayPort CEC-Tunneling-over-AUX HDMI support"
+	select CEC_CORE
+	help
+	  Choose this option if you want to enable HDMI CEC support for
+	  DisplayPort/USB-C to HDMI adapters.
+
+	  Note: not all adapters support this feature, and even for those
+	  that do support this they often do not hook up the CEC pin.
+
 config DRM_TTM
 	tristate
 	depends on DRM && MMU

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
@@ -41,6 +41,7 @@ drm_kms_helper-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o
 drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o
 drm_kms_helper-$(CONFIG_DRM_KMS_CMA_HELPER) += drm_fb_cma_helper.o
 drm_kms_helper-$(CONFIG_DRM_DP_AUX_CHARDEV) += drm_dp_aux_dev.o
+drm_kms_helper-$(CONFIG_DRM_DP_CEC) += drm_dp_cec.o
 
 obj-$(CONFIG_DRM_KMS_HELPER) += drm_kms_helper.o
 obj-$(CONFIG_DRM_DEBUG_SELFTEST) += selftests/