Re: [PATCH 00/14] Add initial support for the Rockchip RK3588 HDMI TX Controller

[Neil Armstrong]

Hi Christian,

On 01/06/2024 15:12, Cristian Ciocaltea wrote:
> The RK3588 SoC family integrates a Quad-Pixel (QP) variant of the
> Synopsys DesignWare HDMI TX controller used in the previous SoCs.
>
> It is HDMI 2.1 compliant and supports the following features, among
> others:
.

..

> * SCDC I2C DDC access
> * TMDS Scrambler enabling 2160p@60Hz with RGB/YCbCr4:4:4
> * YCbCr4:2:0 enabling 2160p@60Hz at lower HDMI link speeds
> * Multi-stream audio
> * Enhanced Audio Return Channel (EARC)
-> Those features were already supported by the HDMI 2.0a compliant HW, just
list the _new_ features for HDMI 2.1

I did a quick review of your patchset and I don't understand why you need
to add a separate dw-hdmi-qp.c since you only need simple variants of the I2C
bus, infoframe and bridge setup.

Can you elaborate further ? isn't this Quad-Pixel (QP) TX controller version
detectable at runtime ?

I would prefer to keep a single dw-hdmi driver if possible.

Thanks,
Neil

> This is the last required component that needs to be supported in order
> to enable the HDMI output functionality on the RK3588 based SBCs, such
> as the RADXA Rock 5B. The other components are the Video Output
> Processor (VOP2) and the Samsung IP based HDMI/eDP TX Combo PHY, for
> which basic support has been already made available via [1] and [2],
> respectively.
>
> The patches are grouped as follows:
> * PATCH 1..7: DW HDMI TX driver refactor to minimize code duplication in
>    the new QP driver (no functional changes intended)
>
> * PATCH 8..11: Rockchip DW HDMI glue driver cleanup/improvements (no
>    functional changes intended)
>
> * PATCH 12..13: The new DW HDMI QP TX driver reusing the previously
>    exported functions and structs from existing DW HDMI TX driver
>
> * PATCH 14: Rockchip DW HDMI glue driver update to support RK3588 and
>    make use of DW HDMI QP TX
>
> They provide just the basic HDMI support for now, i.e. RGB output up to
> 4K@60Hz, without audio, CEC or any of the HDMI 2.1 specific features.
> Also note the vop2 driver is currently not able to properly handle all
> display modes supported by the connected screens, e.g. it doesn't cope
> with non-integer refresh rates.
>
> A possible workaround consists of enabling the display controller to
> make use of the clock provided by the HDMI PHY PLL. This is still work
> in progress and will be submitted later, as well as the required DTS
> updates.
>
> To facilitate testing and experimentation, all HDMI output related
> patches, including those part of this series, are available at [3].
> So far I could only verify this on the RADXA Rock 3A and 5B boards.
>
> Thanks,
> Cristian
>
> [1]: 5a028e8f062f ("drm/rockchip: vop2: Add support for rk3588")
> [2]: 553be2830c5f ("phy: rockchip: Add Samsung HDMI/eDP Combo PHY driver")
> [3]: https://gitlab.collabora.com/hardware-enablement/rockchip-3588/linux/-/commits/rk3588-hdmi-bridge-v6.10-rc1
>
> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@xxxxxxxxxxxxx>
> ---
> Cristian Ciocaltea (14):
>        drm/bridge: dw-hdmi: Simplify clock handling
>        drm/bridge: dw-hdmi: Add dw-hdmi-common.h header
>        drm/bridge: dw-hdmi: Commonize dw_hdmi_i2c_adapter()
>        drm/bridge: dw-hdmi: Factor out AVI infoframe setup
>        drm/bridge: dw-hdmi: Factor out vmode setup
>        drm/bridge: dw-hdmi: Factor out hdmi_data_info setup
>        drm/bridge: dw-hdmi: Commonize dw_hdmi_connector_create()
>        drm/rockchip: dw_hdmi: Use modern drm_device based logging
>        drm/rockchip: dw_hdmi: Simplify clock handling
>        drm/rockchip: dw_hdmi: Use devm_regulator_get_enable()
>        drm/rockchip: dw_hdmi: Drop superfluous assignments of mpll_cfg, cur_ctr and phy_config
>        dt-bindings: display: rockchip,dw-hdmi: Add compatible for RK3588
>        drm/bridge: synopsys: Add DW HDMI QP TX controller driver
>        drm/rockchip: dw_hdmi: Add basic RK3588 support
>
>   .../display/rockchip/rockchip,dw-hdmi.yaml         | 127 +++-
>   drivers/gpu/drm/bridge/synopsys/Makefile           |   2 +-
>   drivers/gpu/drm/bridge/synopsys/dw-hdmi-common.h   | 179 +++++
>   drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c       | 787 +++++++++++++++++++
>   drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.h       | 831 +++++++++++++++++++++
>   drivers/gpu/drm/bridge/synopsys/dw-hdmi.c          | 353 +++------
>   drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c        | 351 +++++++--
>   include/drm/bridge/dw_hdmi.h                       |   8 +
>   8 files changed, 2290 insertions(+), 348 deletions(-)
> ---
> base-commit: 1613e604df0cd359cf2a7fbd9be7a0bcfacfabd0
> change-id: 20240601-b4-rk3588-bridge-upstream-a27baff1b8fc