drm/mediatek: Introduce HDMI/DDC v2 for MT8195/MT8188

drm/mediatek: Introduce HDMI/DDC v2 for MT8195/MT8188

Add support for the newer HDMI-TX (Encoder) v2 and DDC v2 IPs
found in MediaTek's MT8195, MT8188 SoC and their variants, and
including support for display modes up to 4k60 and for HDMI
Audio, as per the HDMI 2.0 spec.

HDCP and CEC functionalities are also supported by this hardware,
but are not included in this commit and that also poses a slight
difference between the V2 and V1 controllers in how they handle
Hotplug Detection (HPD).

While the v1 controller was using the CEC controller to check
HDMI cable connection and disconnection, in this driver the v2
one does not.

This is due to the fact that on parts with v2 designs, like the
MT8195 SoC, there is one CEC controller shared between the HDMI
Transmitter (HDMI-TX) and Receiver (HDMI-RX): before eventually
adding support to use the CEC HW to wake up the HDMI controllers
it is necessary to have support for one TX, one RX *and* for both
at the same time.

Reviewed-by: CK Hu <ck.hu@mediatek.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Louis-Alexis Eyraud <louisalexis.eyraud@collabora.com>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20251023-mediatek-drm-hdmi-v2-v11-9-7873ec4a1edf@collabora.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
ddc_v2

ddc_v2