[PATCH 00/60] drm/omap: Replace custom display drivers with drm_bridge and drm_panel

Laurent Pinchart laurent.pinchart at ideasonboard.com
Thu Aug 8 14:31:38 UTC 2019


Hi Daniel,

On Thu, Jul 11, 2019 at 09:37:26AM +0200, Daniel Vetter wrote:
> On Sun, Jul 07, 2019 at 09:07:52PM +0300, Laurent Pinchart wrote:
> > Hello,
> > 
> > This patch series (nearly, see [1]) completes the rework of the omapdrm
> > driver to move to drm_bridge and drm_panel.
> > 
> > What a journey. This work was started more than a year ago, and this
> > last piece is perhaps the one that will generate the most bikeshedding
> > as it touches the DRM core. I'm braced for the impact, but please be
> > gentle :-)
> > 
> > Let's start with some context to understand the problem. omapdrm
> > contains custom drivers for external encoders, panels and connectors
> > (collectively referred to as display drivers). It combines them to
> > create output pipelines abstracted by a drm_encoder and a drm_connector,
> > with the ability to delegate the encoder and connector operations to the
> > component in the pipeline that implements them. For instance, for an
> > HDMI output pipeline, the hot plug detection and the EDID read can be
> > implemented by two different components, when they are handled by two
> > different devices at the hardware level.
> > 
> > DRM/KMS uses drm_bridge and drm_panel to abstract external encoders and
> > panels. The model is however simpler than what omapdrm provides, as
> > bridges were designed to be simple add-ons at the output of a
> > drm_encoder. The ability to chain bridges exists, but a bridge driver
> > hardcodes in its design its position in the pipeline : bridges that
> > expect to terminate the pipeline create a drm_connector, while bridges
> > that expect to be an intermediate component in the pipeline do not
> > create a connector. In addition to not supporting bridges that can be
> > either internal or a termination point in the pipeline depending on the
> > hardware design, implementing the drm_connector inside a bridge driver
> > makes it impossible to support hardware where bridge operations are
> > handled by different hardware components, as explained above.
> > 
> > The omapdrm driver has received support for drm_bridge and drm_panel,
> > but these issues prevented completely moving away from the omapdrm
> > custom display drivers. This patch series thus first reworks the
> > drm_bridge infrastructure to support the omapdrm use cases, and then
> > transitions the omapdrm driver.
> > 
> > The series starts by 01/60 that adds a new flag to the drm_display_info
> > structure to identify HDMI sinks. This is a feature needed by the OMAP4
> > and OMAP5 HDMI encoders, and I believe it can be useful to other HDMI
> > encoders as well. 02/60 is then a small drive-by cleanup.
> > 
> > The first sizeable change follows with the rename of the dumb-vga-dac
> > driver to simple-bridge (03/60 and 04/60) and support for non-VGA
> > bridges (05/60). This doesn't change the spirit of the driver that still
> > focusses on transparent bridges, but prepares it to support an analog
> > video amplifier. Patches 06/60 then add support for an enable GPIO, and
> > 07/60 support for the OPA362 video amplifier itself.
> > 
> > The next two patches address the drm_bridge issues explained above.
> > Patch 08/60 makes it possible to attach to a bridge without having the
> > bridge create a connector. The connector is expected to be created by
> > the display controller driver. Patch 09/60 adds connector-related
> > operations to drm_bridge to make this possible.
> > 
> > The approach taken here is slightly intrusive as path 08/60 adds a
> > parameter to tbe bridge .attach() operation, and thus touches all bridge
> > drivers, even if the changes are very simple (as a consequence I haven't
> > CC'ed all the individual bridge maintainers as the CC list was too
> > large). Other options may be possible, what matters most to me is the
> > feature, not so much its implementation. Please note that I envision the
> > parameter to be removed down the road once all bridge drivers will be
> > converted to the new model (but this will likely take time, and both
> > models can co-exist for as long as necessary).
> > 
> > The next six patches make use of these new features: patches 10/60 and
> > 11/60 add new bridge drivers for display connectors and for the TI
> > TPD12S015 HDMI level shifter respectively, patch 12/60 supports the new
> > API in the panel bridge driver, and patches 13/60 to 15/60 do the same
> > in the ti-tfp410 driver.
> > 
> > The nine patches that follow add support for six new panels, with the
> > related DT bindings (16/60 to 18/60) and the drm_panel drivers (19/60 to
> > 24/60). The code originates from the corresponding omapdrm-specific
> > panel drivers (which explains why only three DT patches are needed as
> > most of the bindings are already present).
> > 
> > Patch 25/60 is possibly the most remarkable one in the series, with the
> > drm_bridge operations extension, as it provides a helper for display
> > controller drivers to construct a drm_connector entirerly backed by a
> > chain of bridges. This offsets the complexity of the additional bridge
> > operations by handling it all in a single place. An example usage for
> > omapdrm can be found in patch 43/60. Don't let its diffstat mislead you,
> > usage of the helper would remove lots of code if it wasn't for the fact
> > that the legacy implementation still has to be kept for the DSI panel
> > (see [1]). Down the road this helper and the new operation paradigm
> > should remove code from both display controller and bridge drivers.
> > 
> > The rest of the series is omapdrm-focussed, slowly preparing the driver
> > for the switch to drm_bridge drivers using the new helper (43/60), the
> > removal of the omapdrm-specific display drivers (44/60 and 50/60), and
> > lots of simplification and code removal in the other patches.
> 
> git branch pls, thanks.

Sorry about that.

	git://linuxtv.org/pinchartl/media.git omapdrm/bridge/devel

(regularly updated with new versions)

> > [1] The only notable exception is the omapdrm-specific DSI panel driver
> > that implements a large number of custom operations. This should be
> > addressed separately.
> 
> DSI tends to be fairly custom in all drivers, I think that's totally fine.
> Maybe not forever, but we have a lot worse crimes in our codebase than
> that :-)
> 
> > Laurent Pinchart (60):
> >   drm/edid: Add flag to drm_display_info to identify HDMI sinks
> >   video: hdmi: Change return type of hdmi_avi_infoframe_init() to void
> >   drm/bridge: dumb-vga-dac: Rename internal symbols to simple-bridge
> >   drm/bridge: dumb-vga-dac: Rename driver to simple-bridge
> >   drm/bridge: simple-bridge: Add support for non-VGA bridges
> >   drm/bridge: simple-bridge: Add support for enable GPIO
> >   drm/bridge: simple-bridge: Add support for the TI OP362
> >   drm/bridge: Extend bridge API to disable connector creation
> >   drm/bridge: Add connector-related bridge operations and data
> >   drm/bridge: Add bridge driver for display connectors
> >   drm/bridge: Add driver for the TI TPD12S015 HDMI level shifter
> >   drm/bridge: panel: Implement bridge connector operations
> >   drm/bridge: tfp410: Don't include drmP.h
> >   drm/bridge: tfp410: Replace manual connector handling with bridge
> >   drm/bridge: tfp410: Allow operation without drm_connector
> >   dt-bindings: Add vendor prefix for LG Display
> >   dt-bindings: Add legacy 'toppoly' vendor prefix
> >   dt-bindings: display: panel: Add bindings for NEC NL8048HL11 panel
> >   drm/panel: Add driver for the LG Philips LB035Q02 panel
> >   drm/panel: Add driver for the NEC NL8048HL11 panel
> >   drm/panel: Add driver for the Sharp LS037V7DW01 panel
> >   drm/panel: Add driver for the Sony ACX565AKM panel
> >   drm/panel: Add driver for the Toppology TD028TTEC1 panel
> >   drm/panel: Add driver for the Toppology TD043MTEA1 panel
> >   drm: Add helper to create a connector for a chain of bridges
> >   drm/omap: Detach from panels at remove time
> >   drm/omap: Simplify HDMI mode and infoframe configuration
> >   drm/omap: Factor out display type to connector type conversion
> >   drm/omap: Use the drm_panel_bridge API
> >   drm/omap: dss: Fix output next device lookup in DT
> >   drm/omap: Add infrastructure to support drm_bridge local to DSS
> >     outputs
> >   drm/omap: dss: Make omap_dss_device_ops optional
> >   drm/omap: hdmi: Allocate EDID in the .read_edid() operation
> >   drm/omap: hdmi4: Rework EDID read to isolate data read
> >   drm/omap: hdmi5: Rework EDID read to isolate data read
> >   drm/omap: hdmi4: Register a drm_bridge for EDID read
> >   drm/omap: hdmi5: Register a drm_bridge for EDID read
> >   drm/omap: hdmi4: Move mode set, enable and disable operations to
> >     bridge
> >   drm/omap: hdmi5: Move mode set, enable and disable operations to
> >     bridge
> >   drm/omap: hdmi4: Implement drm_bridge .lost_hotplug() operation
> >   drm/omap: dss: Remove .set_hdmi_mode() and .set_infoframe() operations
> >   drm/omap: venc: Register a drm_bridge
> >   drm/omap: Create connector for bridges
> >   drm/omap: Switch the HDMI and VENC outputs to drm_bridge
> >   drm/omap: Remove HPD, detect and EDID omapdss operations
> >   drm/omap: hdmi: Remove omap_dss_device operations
> >   drm/omap: venc: Remove omap_dss_device operations
> >   drm/omap: hdmi4: Simplify EDID read
> >   drm/omap: hdmi5: Simplify EDID read
> >   drm/omap: displays: Remove unused panel drivers
> >   drm/omap: dpi: Sort includes alphabetically
> >   drm/omap: dpi: Reorder functions in sections
> >   drm/omap: dpi: Simplify clock setting API
> >   drm/omap: dpi: Register a drm_bridge
> >   drm/omap: sdi: Sort includes alphabetically
> >   drm/omap: sdi: Register a drm_bridge
> >   drm/omap: Simplify connector implementation
> >   drm/omap: dss: Remove unused omap_dss_device operations
> >   drm/omap: dss: Inline the omapdss_display_get() function
> >   drm/omap: dss: Remove unused omapdss_of_find_connected_device()
> >     function
> > 
> >  .../bindings/display/panel/nec,nl8048hl11.txt |  38 +
> >  .../devicetree/bindings/vendor-prefixes.yaml  |   4 +
> >  arch/arm/configs/davinci_all_defconfig        |   2 +-
> >  arch/arm/configs/integrator_defconfig         |   2 +-
> >  arch/arm/configs/multi_v7_defconfig           |   2 +-
> >  arch/arm/configs/shmobile_defconfig           |   2 +-
> >  arch/arm/configs/sunxi_defconfig              |   2 +-
> >  arch/arm/configs/versatile_defconfig          |   2 +-
> >  drivers/gpu/drm/Makefile                      |   3 +-
> >  drivers/gpu/drm/arc/arcpgu_hdmi.c             |   2 +-
> >  .../gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c  |   2 +-
> >  drivers/gpu/drm/bridge/Kconfig                |  29 +-
> >  drivers/gpu/drm/bridge/Makefile               |   4 +-
> >  drivers/gpu/drm/bridge/adv7511/adv7511_drv.c  |   6 +-
> >  drivers/gpu/drm/bridge/analogix-anx78xx.c     |   6 +-
> >  .../drm/bridge/analogix/analogix_dp_core.c    |   8 +-
> >  drivers/gpu/drm/bridge/cdns-dsi.c             |   6 +-
> >  drivers/gpu/drm/bridge/display-connector.c    | 327 ++++++++
> >  drivers/gpu/drm/bridge/dumb-vga-dac.c         | 296 -------
> >  drivers/gpu/drm/bridge/lvds-encoder.c         |   4 +-
> >  .../bridge/megachips-stdpxxxx-ge-b850v3-fw.c  |   6 +-
> >  drivers/gpu/drm/bridge/nxp-ptn3460.c          |   6 +-
> >  drivers/gpu/drm/bridge/panel.c                |  21 +-
> >  drivers/gpu/drm/bridge/parade-ps8622.c        |   5 +-
> >  drivers/gpu/drm/bridge/sii902x.c              |   6 +-
> >  drivers/gpu/drm/bridge/sil-sii8620.c          |   2 +-
> >  drivers/gpu/drm/bridge/simple-bridge.c        | 337 ++++++++
> >  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c     |   8 +-
> >  drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c |   8 +-
> >  drivers/gpu/drm/bridge/tc358764.c             |   5 +-
> >  drivers/gpu/drm/bridge/tc358767.c             |   5 +-
> >  drivers/gpu/drm/bridge/thc63lvd1024.c         |   5 +-
> >  drivers/gpu/drm/bridge/ti-sn65dsi86.c         |   5 +-
> >  drivers/gpu/drm/bridge/ti-tfp410.c            | 202 ++---
> >  drivers/gpu/drm/bridge/ti-tpd12s015.c         | 204 +++++
> >  drivers/gpu/drm/drm_bridge.c                  |  97 ++-
> >  drivers/gpu/drm/drm_bridge_connector.c        | 385 +++++++++
> >  drivers/gpu/drm/drm_edid.c                    |   8 +-
> >  drivers/gpu/drm/drm_simple_kms_helper.c       |   2 +-
> >  drivers/gpu/drm/exynos/exynos_dp.c            |   3 +-
> >  drivers/gpu/drm/exynos/exynos_drm_dsi.c       |   4 +-
> >  drivers/gpu/drm/exynos/exynos_hdmi.c          |   2 +-
> >  drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c     |   2 +-
> >  drivers/gpu/drm/hisilicon/kirin/dw_drm_dsi.c  |   2 +-
> >  drivers/gpu/drm/i2c/tda998x_drv.c             |   8 +-
> >  drivers/gpu/drm/imx/imx-ldb.c                 |   2 +-
> >  drivers/gpu/drm/imx/parallel-display.c        |   2 +-
> >  drivers/gpu/drm/mcde/mcde_dsi.c               |   6 +-
> >  drivers/gpu/drm/mediatek/mtk_dpi.c            |   2 +-
> >  drivers/gpu/drm/mediatek/mtk_dsi.c            |   2 +-
> >  drivers/gpu/drm/mediatek/mtk_hdmi.c           |   8 +-
> >  drivers/gpu/drm/msm/dsi/dsi_manager.c         |   4 +-
> >  drivers/gpu/drm/msm/edp/edp_bridge.c          |   2 +-
> >  drivers/gpu/drm/msm/hdmi/hdmi_bridge.c        |   2 +-
> >  drivers/gpu/drm/omapdrm/displays/Kconfig      |  60 --
> >  drivers/gpu/drm/omapdrm/displays/Makefile     |  10 -
> >  .../omapdrm/displays/connector-analog-tv.c    | 100 ---
> >  .../gpu/drm/omapdrm/displays/connector-hdmi.c | 186 -----
> >  .../gpu/drm/omapdrm/displays/encoder-opa362.c | 140 ----
> >  .../drm/omapdrm/displays/encoder-tpd12s015.c  | 220 -----
> >  .../gpu/drm/omapdrm/displays/panel-dsi-cm.c   |   2 +-
> >  .../displays/panel-lgphilips-lb035q02.c       | 254 ------
> >  .../omapdrm/displays/panel-nec-nl8048hl11.c   | 271 -------
> >  .../displays/panel-sharp-ls037v7dw01.c        | 265 ------
> >  .../omapdrm/displays/panel-sony-acx565akm.c   | 766 ------------------
> >  .../omapdrm/displays/panel-tpo-td028ttec1.c   | 401 ---------
> >  .../omapdrm/displays/panel-tpo-td043mtea1.c   | 513 ------------
> >  drivers/gpu/drm/omapdrm/dss/Makefile          |   2 +-
> >  drivers/gpu/drm/omapdrm/dss/base.c            |  72 +-
> >  drivers/gpu/drm/omapdrm/dss/display.c         |   9 -
> >  drivers/gpu/drm/omapdrm/dss/dpi.c             | 336 ++++----
> >  drivers/gpu/drm/omapdrm/dss/dsi.c             |   4 +-
> >  drivers/gpu/drm/omapdrm/dss/dss-of.c          |  28 -
> >  drivers/gpu/drm/omapdrm/dss/dss.c             |   3 +-
> >  drivers/gpu/drm/omapdrm/dss/hdmi.h            |   4 +-
> >  drivers/gpu/drm/omapdrm/dss/hdmi4.c           | 321 ++++----
> >  drivers/gpu/drm/omapdrm/dss/hdmi4_core.c      |  59 +-
> >  drivers/gpu/drm/omapdrm/dss/hdmi4_core.h      |   4 +-
> >  drivers/gpu/drm/omapdrm/dss/hdmi5.c           | 303 +++----
> >  drivers/gpu/drm/omapdrm/dss/hdmi5_core.c      |  48 +-
> >  drivers/gpu/drm/omapdrm/dss/hdmi5_core.h      |   5 +-
> >  .../gpu/drm/omapdrm/dss/omapdss-boot-init.c   |  12 -
> >  drivers/gpu/drm/omapdrm/dss/omapdss.h         |  47 +-
> >  drivers/gpu/drm/omapdrm/dss/output.c          |  55 +-
> >  drivers/gpu/drm/omapdrm/dss/sdi.c             | 187 +++--
> >  drivers/gpu/drm/omapdrm/dss/venc.c            | 269 +++---
> >  drivers/gpu/drm/omapdrm/omap_connector.c      | 246 +-----
> >  drivers/gpu/drm/omapdrm/omap_connector.h      |   3 -
> >  drivers/gpu/drm/omapdrm/omap_drv.c            |  98 ++-
> >  drivers/gpu/drm/omapdrm/omap_encoder.c        |  83 +-
> >  drivers/gpu/drm/panel/Kconfig                 |  44 +
> >  drivers/gpu/drm/panel/Makefile                |   6 +
> >  drivers/gpu/drm/panel/panel-lg-lb035q02.c     | 235 ++++++
> >  drivers/gpu/drm/panel/panel-nec-nl8048hl11.c  | 249 ++++++
> >  .../gpu/drm/panel/panel-sharp-ls037v7dw01.c   | 231 ++++++
> >  drivers/gpu/drm/panel/panel-sony-acx565akm.c  | 691 ++++++++++++++++
> >  drivers/gpu/drm/panel/panel-tpo-td028ttec1.c  | 382 +++++++++
> >  drivers/gpu/drm/panel/panel-tpo-td043mtea1.c  | 510 ++++++++++++
> >  drivers/gpu/drm/rcar-du/rcar_du_encoder.c     |   2 +-
> >  drivers/gpu/drm/rcar-du/rcar_lvds.c           |   7 +-
> >  drivers/gpu/drm/rockchip/rockchip_lvds.c      |   2 +-
> >  drivers/gpu/drm/rockchip/rockchip_rgb.c       |   2 +-
> >  drivers/gpu/drm/sti/sti_dvo.c                 |   2 +-
> >  drivers/gpu/drm/sti/sti_hda.c                 |   2 +-
> >  drivers/gpu/drm/sti/sti_hdmi.c                |   2 +-
> >  drivers/gpu/drm/stm/ltdc.c                    |   2 +-
> >  drivers/gpu/drm/sun4i/sun4i_lvds.c            |   2 +-
> >  drivers/gpu/drm/sun4i/sun4i_rgb.c             |   2 +-
> >  drivers/gpu/drm/tilcdc/tilcdc_external.c      |   2 +-
> >  drivers/gpu/drm/vc4/vc4_dpi.c                 |   2 +-
> >  drivers/gpu/drm/vc4/vc4_dsi.c                 |   2 +-
> >  drivers/video/hdmi.c                          |   9 +-
> >  include/drm/drm_bridge.h                      | 174 +++-
> >  include/drm/drm_bridge_connector.h            |  18 +
> >  include/drm/drm_connector.h                   |   5 +
> >  include/linux/hdmi.h                          |   2 +-
> >  116 files changed, 5188 insertions(+), 4900 deletions(-)
> >  create mode 100644 Documentation/devicetree/bindings/display/panel/nec,nl8048hl11.txt
> >  create mode 100644 drivers/gpu/drm/bridge/display-connector.c
> >  delete mode 100644 drivers/gpu/drm/bridge/dumb-vga-dac.c
> >  create mode 100644 drivers/gpu/drm/bridge/simple-bridge.c
> >  create mode 100644 drivers/gpu/drm/bridge/ti-tpd12s015.c
> >  create mode 100644 drivers/gpu/drm/drm_bridge_connector.c
> >  delete mode 100644 drivers/gpu/drm/omapdrm/displays/connector-analog-tv.c
> >  delete mode 100644 drivers/gpu/drm/omapdrm/displays/connector-hdmi.c
> >  delete mode 100644 drivers/gpu/drm/omapdrm/displays/encoder-opa362.c
> >  delete mode 100644 drivers/gpu/drm/omapdrm/displays/encoder-tpd12s015.c
> >  delete mode 100644 drivers/gpu/drm/omapdrm/displays/panel-lgphilips-lb035q02.c
> >  delete mode 100644 drivers/gpu/drm/omapdrm/displays/panel-nec-nl8048hl11.c
> >  delete mode 100644 drivers/gpu/drm/omapdrm/displays/panel-sharp-ls037v7dw01.c
> >  delete mode 100644 drivers/gpu/drm/omapdrm/displays/panel-sony-acx565akm.c
> >  delete mode 100644 drivers/gpu/drm/omapdrm/displays/panel-tpo-td028ttec1.c
> >  delete mode 100644 drivers/gpu/drm/omapdrm/displays/panel-tpo-td043mtea1.c
> >  delete mode 100644 drivers/gpu/drm/omapdrm/dss/dss-of.c
> >  create mode 100644 drivers/gpu/drm/panel/panel-lg-lb035q02.c
> >  create mode 100644 drivers/gpu/drm/panel/panel-nec-nl8048hl11.c
> >  create mode 100644 drivers/gpu/drm/panel/panel-sharp-ls037v7dw01.c
> >  create mode 100644 drivers/gpu/drm/panel/panel-sony-acx565akm.c
> >  create mode 100644 drivers/gpu/drm/panel/panel-tpo-td028ttec1.c
> >  create mode 100644 drivers/gpu/drm/panel/panel-tpo-td043mtea1.c
> >  create mode 100644 include/drm/drm_bridge_connector.h

-- 
Regards,

Laurent Pinchart


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