While porting lt9611 DSI-to-HDMI bridge driver to use HDMI Connector framework, I stumbled upon an issue while handling the Audio InfoFrames. The HDMI codec callbacks weren't receiving the drm_atomic_state, so there was no simple way to get the drm_connector that stayed at the end of the bridge chain. At the same point the drm_hdmi_connector functions expected to get drm_connector instance. While looking for a way to solve the issue, I stumbled upon several deficiencies in existing hdmi_codec_ops implementations. Only few of the implementations were able to handle codec's 'plugged' callback. One third of the drivers didn't implement the get_eld() callback. Most of the issues can be solved if drm_connector handles hdmi-audio-codec on its own, delegating functionality to the actual implementation, be it a driver that implements drm_connector or drm_bridge. Implement such high-level framework, adding proper support for Audio InfoFrame generation to the LT9611 driver. Several design decisions to be kept in mind: - drm_connector_hdmi_codec is kept as simple as possible. It implements generic functionality (ELD, hotplug, registration). - drm_hdmi_connector sets up HDMI codec device if the connector is setup correspondingly (either I2S or S/PDIF is marked as supported). - drm_bridge_connector provides a way to link HDMI audio codec funcionality in the drm_bridge with the drm_connector_hdmi_codec framework. - It might be worth reverting the no_i2s_capture / no_spdif_capture bits. Only TDA889x driver sets them, while it's safe to assume that most of HDMI / DP devices do not support ARC / capture. I think the drivers should opt-in capture support rather than having to opt-out of it. This series is in the RFC stage, so some bits are underdocumented. Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> --- Changes in v3: - Dropped RFC status - Fixed drm_connector_hdmi_codec_init() kerneldoc (LKP) - Dropped double underscore prefix from __drm_atomic_helper_connector_hdmi_update_edid() (Jani) - Moved drm_edid_free() from drm_atomic_helper_connector_hdmi_update_edid() to the caller's side (Jani) - Link to v2: https://lore.kernel.org/r/20241101-drm-bridge-hdmi-connector-v2-0-739ef9addf9e@xxxxxxxxxx Changes in v2: - Use drm_atomic_get_old_connector_for_encoder in atomic_disable() to prevent it from crashing - Reworked HDMI codec init/exit, removing drmm_ calls (Maxime) - Drafted the helper to be called from .detect_ctx() that performs HDMI Connector maintenance duties (Maxime) - Moved no_capture_mute to struct hdmi_codec_pdata - Link to v1: https://lore.kernel.org/r/20240615-drm-bridge-hdmi-connector-v1-0-d59fc7865ab2@xxxxxxxxxx --- Dmitry Baryshkov (7): ASoC: hdmi-codec: pass data to get_dai_id too ASoC: hdmi-codec: move no_capture_mute to struct hdmi_codec_pdata drm/connector: implement generic HDMI codec helpers drm/bridge: connector: add support for HDMI codec framework drm/bridge: lt9611: switch to using the DRM HDMI codec framework drm/display/hdmi: implement connector update functions drm/bridge_connector: hook drm_atomic_helper_connector_hdmi_update_edid() drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/bridge/adv7511/adv7511_audio.c | 3 +- drivers/gpu/drm/bridge/analogix/anx7625.c | 3 +- drivers/gpu/drm/bridge/ite-it66121.c | 2 +- drivers/gpu/drm/bridge/lontium-lt9611.c | 170 ++++++++----------- drivers/gpu/drm/bridge/lontium-lt9611uxc.c | 3 +- drivers/gpu/drm/bridge/sii902x.c | 5 +- .../gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c | 3 +- drivers/gpu/drm/display/drm_bridge_connector.c | 162 ++++++++++++++++-- drivers/gpu/drm/display/drm_hdmi_state_helper.c | 59 +++++++ drivers/gpu/drm/drm_connector.c | 10 ++ drivers/gpu/drm/drm_connector_hdmi_codec.c | 186 +++++++++++++++++++++ drivers/gpu/drm/drm_internal.h | 5 + drivers/gpu/drm/exynos/exynos_hdmi.c | 2 +- drivers/gpu/drm/i2c/tda998x_drv.c | 2 +- drivers/gpu/drm/mediatek/mtk_dp.c | 2 +- drivers/gpu/drm/mediatek/mtk_hdmi.c | 2 +- drivers/gpu/drm/rockchip/cdn-dp-core.c | 2 +- drivers/gpu/drm/sti/sti_hdmi.c | 2 +- include/drm/display/drm_hdmi_state_helper.h | 4 + include/drm/drm_bridge.h | 23 +++ include/drm/drm_connector.h | 80 +++++++++ include/sound/hdmi-codec.h | 7 +- sound/soc/codecs/hdmi-codec.c | 4 +- 24 files changed, 606 insertions(+), 136 deletions(-) --- base-commit: 929beafbe7acce3267c06115e13e03ff6e50548a change-id: 20240530-drm-bridge-hdmi-connector-9b0f6725973e Best regards, -- Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
