Re: [PATCH v4 00/16] R-Car DU: Convert LVDS code to bridge driver

From: Laurent Pinchart
Date: Thu Feb 22 2018 - 05:24:34 EST

Hi Frank,

On Thursday, 22 February 2018 08:07:14 EET Frank Rowand wrote:
> On 02/20/18 15:10, Laurent Pinchart wrote:
> > Hello,
> >
> > This patch series addresses a design mistake that dates back from the
> > initial DU support. Support for the LVDS encoders, which are IP cores
> > separate from the DU, was bundled in the DU driver. Worse, both the DU
> > and LVDS were described through a single DT node.
> >
> > To fix the, patches 01/16 and 02/16 define new DT bindings for the LVDS
> > encoders, and deprecate their description inside the DU bindings. To
> > retain backward compatibility with existing DT, patches 03/16 to 08/16
> > then patch the device tree at runtime to convert the legacy bindings to
> > the new ones.
> >
> > With the DT side addressed, patch 09/16 converts the LVDS support code to
> > a separate bridge driver. Patches 11/16 to 16/16 then update all the
> > device tree sources to the new DU and LVDS encoders bindings.
> >
> > I decided to go for live DT patching in patch 08/16 because implementing
> > support for both the legacy and new bindings in the driver would have been
> > very intrusive, and prevented further cleanups. This version relies more
> > heavily on overlays to avoid touching the internals of the OF core
> > compared to v2, even if manual fixes to the device tree are still needed.
> >
> > Compared to v3, this series uses the OF changeset API to update properties
> > instead of accessing the internals of the property structure. This removes
> > the local implementation of functions to look up nodes by path and update
> > properties. In order to do this, I pulled in Pantelis' patch series
> > titled "[PATCH v2 0/5] of: dynamic: Changesets helpers & fixes" at Rob's
> > request, and rebased it while taking two small review comments into
> > account.
>
> Wait a minute! Why are you putting a patch set to modify core devicetree
> in the middle of a driver series. Please pull it out to a separate series.

Because Rob asked for the driver-local implementation of the property add
function to be replaced by Pantelis' series. I want to get the LVDS changes in
v4.17 and asked Rob whether I could then take the OF changeset patches merged
through the DRM tree, and he didn't object. If that causes an issue I'll
switch back to the driver-local implementation to get the driver changes
merged, split the OF changeset series out, and then move to the OF changeset
API once merged. Would you prefer that ?

> I'll try to look at the patches, as they are in this series, sometime
> tomorrow. I have a vague memory of unresolved issues from the last
> time they were proposed.
>
> > Rob, I'd like this series to be merged in v4.17. As the changeset helpers
> > are now a dependency, I'd need you to merge them early (ideally on top of
> > v4.16-rc1) and provide a stable branch, or get your ack to merge them
> > through Dave's tree if they don't conflict with what you have and will
> > queue for v4.17.
> >
> > This version also drops the small fix to the Porter board device tree that
> > has been queued for v4.17 already.
> >
> > Compared to v2, the biggest change is in patch 03/16. Following Rob's and
> > Frank's reviews it was clear that modifying the unflattened DT structure
> > of the overlay before applying it wasn't popular. I have thus decided to
> > use one overlay source per SoC to move as much of the DT changes to the
> > overlay as possible, and only perform manual modifications (that are
> > still needed as some of the information is board-specific) on the system
> > DT after applying the overlay. As a result the overlay is parsed and
> > applied without being modified.
> >
> > Compared to v1, this series update the r8a7792 and r8a7794 device tree
> > sources and incorporate review feedback as described by the changelogs of
> > individual patches.
> >
> > Laurent Pinchart (11):
> > dt-bindings: display: renesas: Add R-Car LVDS encoder DT bindings
> > dt-bindings: display: renesas: Deprecate LVDS support in the DU
> > bindings
> > drm: rcar-du: Fix legacy DT to create LVDS encoder nodes
> > drm: rcar-du: Convert LVDS encoder code to bridge driver
> > ARM: dts: r8a7790: Convert to new LVDS DT bindings
> > ARM: dts: r8a7791: Convert to new LVDS DT bindings
> > ARM: dts: r8a7792: Convert to new DU DT bindings
> > ARM: dts: r8a7793: Convert to new LVDS DT bindings
> > ARM: dts: r8a7794: Convert to new DU DT bindings
> > arm64: dts: renesas: r8a7795: Convert to new LVDS DT bindings
> > arm64: dts: renesas: r8a7796: Convert to new LVDS DT bindings
> >
> > Pantelis Antoniou (5):
> > of: dynamic: Add __of_node_dupv()
> > of: changesets: Introduce changeset helper methods
> > of: changeset: Add of_changeset_node_move method
> > of: unittest: changeset helpers
> > i2c: demux: Use changeset helpers for clarity
> >
> > .../bindings/display/bridge/renesas,lvds.txt | 56 +++
> > .../devicetree/bindings/display/renesas,du.txt | 31 +-
> > MAINTAINERS | 1 +
> > arch/arm/boot/dts/r8a7790-lager.dts | 22 +-
> > arch/arm/boot/dts/r8a7790.dtsi | 64 ++-
> > arch/arm/boot/dts/r8a7791-koelsch.dts | 10 +-
> > arch/arm/boot/dts/r8a7791-porter.dts | 16 +-
> > arch/arm/boot/dts/r8a7791.dtsi | 36 +-
> > arch/arm/boot/dts/r8a7792.dtsi | 1 -
> > arch/arm/boot/dts/r8a7793-gose.dts | 10 +-
> > arch/arm/boot/dts/r8a7793.dtsi | 37 +-
> > arch/arm/boot/dts/r8a7794.dtsi | 1 -
> > .../boot/dts/renesas/r8a7795-es1-salvator-x.dts | 3 +-
> > arch/arm64/boot/dts/renesas/r8a7795-h3ulcb.dts | 3 +-
> > arch/arm64/boot/dts/renesas/r8a7795-salvator-x.dts | 3 +-
> > .../arm64/boot/dts/renesas/r8a7795-salvator-xs.dts | 3 +-
> > arch/arm64/boot/dts/renesas/r8a7795.dtsi | 36 +-
> > arch/arm64/boot/dts/renesas/r8a7796-m3ulcb.dts | 3 +-
> > arch/arm64/boot/dts/renesas/r8a7796-salvator-x.dts | 3 +-
> > arch/arm64/boot/dts/renesas/r8a7796.dtsi | 36 +-
> > drivers/gpu/drm/rcar-du/Kconfig | 6 +-
> > drivers/gpu/drm/rcar-du/Makefile | 10 +-
> > drivers/gpu/drm/rcar-du/rcar_du_drv.c | 21 +-
> > drivers/gpu/drm/rcar-du/rcar_du_drv.h | 5 -
> > drivers/gpu/drm/rcar-du/rcar_du_encoder.c | 175 +------
> > drivers/gpu/drm/rcar-du/rcar_du_encoder.h | 12 -
> > drivers/gpu/drm/rcar-du/rcar_du_kms.c | 14 +-
> > drivers/gpu/drm/rcar-du/rcar_du_lvdscon.c | 93 ----
> > drivers/gpu/drm/rcar-du/rcar_du_lvdscon.h | 24 -
> > drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c | 238 ----------
> > drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.h | 64 ---
> > drivers/gpu/drm/rcar-du/rcar_du_of.c | 307 ++++++++++++
> > drivers/gpu/drm/rcar-du/rcar_du_of.h | 20 +
> > .../gpu/drm/rcar-du/rcar_du_of_lvds_r8a7790.dts | 81 ++++
> > .../gpu/drm/rcar-du/rcar_du_of_lvds_r8a7791.dts | 55 +++
> > .../gpu/drm/rcar-du/rcar_du_of_lvds_r8a7793.dts | 55 +++
> > .../gpu/drm/rcar-du/rcar_du_of_lvds_r8a7795.dts | 55 +++
> > .../gpu/drm/rcar-du/rcar_du_of_lvds_r8a7796.dts | 55 +++
> > drivers/gpu/drm/rcar-du/rcar_lvds.c | 524 ++++++++++++++++
> > drivers/i2c/muxes/i2c-demux-pinctrl.c | 12 +-
> > drivers/of/dynamic.c | 317 ++++++++++++-
> > drivers/of/unittest.c | 54 +++
> > include/linux/of.h | 337 +++++++++++++
> > 43 files changed, 2199 insertions(+), 710 deletions(-)
> > create mode 100644
> > Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt delete
> > mode 100644 drivers/gpu/drm/rcar-du/rcar_du_lvdscon.c
> > delete mode 100644 drivers/gpu/drm/rcar-du/rcar_du_lvdscon.h
> > delete mode 100644 drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
> > delete mode 100644 drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.h
> > create mode 100644 drivers/gpu/drm/rcar-du/rcar_du_of.c
> > create mode 100644 drivers/gpu/drm/rcar-du/rcar_du_of.h
> > create mode 100644 drivers/gpu/drm/rcar-du/rcar_du_of_lvds_r8a7790.dts
> > create mode 100644 drivers/gpu/drm/rcar-du/rcar_du_of_lvds_r8a7791.dts
> > create mode 100644 drivers/gpu/drm/rcar-du/rcar_du_of_lvds_r8a7793.dts
> > create mode 100644 drivers/gpu/drm/rcar-du/rcar_du_of_lvds_r8a7795.dts
> > create mode 100644 drivers/gpu/drm/rcar-du/rcar_du_of_lvds_r8a7796.dts
> > create mode 100644 drivers/gpu/drm/rcar-du/rcar_lvds.c

--
Regards,

Laurent Pinchart