mbox series

[RFC,00/13] drm/connector: Create HDMI Connector infrastructure

Message ID 20230814-kms-hdmi-connector-state-v1-0-048054df3654@kernel.org
Headers
Series drm/connector: Create HDMI Connector infrastructure |

Message

Maxime Ripard Aug. 14, 2023, 1:56 p.m. UTC 
  Hi,

Here's a series that creates a subclass of drm_connector specifically
targeted at HDMI controllers.

The idea behind this series came from a recent discussion on IRC during
which we discussed infoframes generation of i915 vs everything else. 

Infoframes generation code still requires some decent boilerplate, with
each driver doing some variation of it.

In parallel, while working on vc4, we ended up converting a lot of i915
logic (mostly around format / bpc selection, and scrambler setup) to
apply on top of a driver that relies only on helpers.

While currently sitting in the vc4 driver, none of that logic actually
relies on any driver or hardware-specific behaviour.

The only missing piec to make it shareable are a bunch of extra
variables stored in a state (current bpc, format, RGB range selection,
etc.).

Thus, I decided to create some generic subclass of drm_connector to
address HDMI connectors, with a bunch of helpers that will take care of
all the "HDMI Spec" related code. Scrambler setup is missing at the
moment but can easily be plugged in.

Last week, Hans Verkuil also expressed interest in retrieving the
infoframes generated from userspace to create an infoframe-decode tool.
This series thus leverages the infoframe generation code to expose it
through debugfs.

This entire series is only build-tested at the moment. Let me know what
you think,
Maxime

Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
Maxime Ripard (13):
      drm/connector: Introduce an HDMI connector
      drm/connector: hdmi: Create a custom state
      drm/connector: hdmi: Add Broadcast RGB property
      drm/connector: hdmi: Add helper to get the RGB range
      drm/connector: hdmi: Add output BPC to the connector state
      drm/connector: hdmi: Add support for output format
      drm/connector: hdmi: Calculate TMDS character rate
      drm/connector: hdmi: Add custom hook to filter TMDS character rate
      drm/connector: hdmi: Compute bpc and format automatically
      drm/connector: hdmi: Add Infoframes generation
      drm/connector: hdmi: Create Infoframe DebugFS entries
      drm/vc4: hdmi: Create destroy state implementation
      drm/vc4: hdmi: Switch to HDMI connector

 drivers/gpu/drm/Makefile             |    1 +
 drivers/gpu/drm/drm_hdmi_connector.c | 1112 ++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/vc4/vc4_hdmi.c       |  720 ++++------------------
 drivers/gpu/drm/vc4/vc4_hdmi.h       |   37 +-
 drivers/gpu/drm/vc4/vc4_hdmi_phy.c   |    4 +-
 include/drm/drm_connector.h          |  256 ++++++++
 6 files changed, 1508 insertions(+), 622 deletions(-)
---
base-commit: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4
change-id: 20230814-kms-hdmi-connector-state-616787e67927

Best regards,

Comments

Hans Verkuil Aug. 16, 2023, 8:43 a.m. UTC | #1 
On 14/08/2023 15:56, Maxime Ripard wrote:
> Hi,
> 
> Here's a series that creates a subclass of drm_connector specifically
> targeted at HDMI controllers.
> 
> The idea behind this series came from a recent discussion on IRC during
> which we discussed infoframes generation of i915 vs everything else. 
> 
> Infoframes generation code still requires some decent boilerplate, with
> each driver doing some variation of it.
> 
> In parallel, while working on vc4, we ended up converting a lot of i915
> logic (mostly around format / bpc selection, and scrambler setup) to
> apply on top of a driver that relies only on helpers.
> 
> While currently sitting in the vc4 driver, none of that logic actually
> relies on any driver or hardware-specific behaviour.
> 
> The only missing piec to make it shareable are a bunch of extra
> variables stored in a state (current bpc, format, RGB range selection,
> etc.).
> 
> Thus, I decided to create some generic subclass of drm_connector to
> address HDMI connectors, with a bunch of helpers that will take care of
> all the "HDMI Spec" related code. Scrambler setup is missing at the
> moment but can easily be plugged in.
> 
> Last week, Hans Verkuil also expressed interest in retrieving the
> infoframes generated from userspace to create an infoframe-decode tool.
> This series thus leverages the infoframe generation code to expose it
> through debugfs.

Some background here: I maintain the edid-decode utility to parse and verify
EDIDs, and an infoframe-decode counterpart would be very nice. I can add
support for exposing infoframes to debugfs in HDMI receivers as well, and
that will help parse and verify received infoframes for correctness.

I added the linux-media mailinglist as well, since this will be of interest
for that subsystem as well.

Regards,

	Hans

> 
> This entire series is only build-tested at the moment. Let me know what
> you think,
> Maxime
> 
> Signed-off-by: Maxime Ripard <mripard@kernel.org>
> ---
> Maxime Ripard (13):
>       drm/connector: Introduce an HDMI connector
>       drm/connector: hdmi: Create a custom state
>       drm/connector: hdmi: Add Broadcast RGB property
>       drm/connector: hdmi: Add helper to get the RGB range
>       drm/connector: hdmi: Add output BPC to the connector state
>       drm/connector: hdmi: Add support for output format
>       drm/connector: hdmi: Calculate TMDS character rate
>       drm/connector: hdmi: Add custom hook to filter TMDS character rate
>       drm/connector: hdmi: Compute bpc and format automatically
>       drm/connector: hdmi: Add Infoframes generation
>       drm/connector: hdmi: Create Infoframe DebugFS entries
>       drm/vc4: hdmi: Create destroy state implementation
>       drm/vc4: hdmi: Switch to HDMI connector
> 
>  drivers/gpu/drm/Makefile             |    1 +
>  drivers/gpu/drm/drm_hdmi_connector.c | 1112 ++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/vc4/vc4_hdmi.c       |  720 ++++------------------
>  drivers/gpu/drm/vc4/vc4_hdmi.h       |   37 +-
>  drivers/gpu/drm/vc4/vc4_hdmi_phy.c   |    4 +-
>  include/drm/drm_connector.h          |  256 ++++++++
>  6 files changed, 1508 insertions(+), 622 deletions(-)
> ---
> base-commit: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4
> change-id: 20230814-kms-hdmi-connector-state-616787e67927
> 
> Best regards,