[PATCH v7 0/4] drm: add support for Cadence MHDP DPI/DP bridge.

[Damian Kos <dkos@cadence.com>]

Hello!

This is the series of patches that will add support for the Cadence's DPI/DP
bridge. Please note that this is a preliminary version of the driver and there
will be more patches in the future with updates, fixes and improvements.
Please keep that in mind when looking at FIXME/TODO/XXX comments.

Initially, MHDP driver was developed as a DRM bridge driver and was planed to
be placed in drivers/gpu/drm/bridge/mhdp.c.  However, there was already
a driver for Cadence's DP controller developed by RockChip, but that driver
uses the different DRM framework and looks like a part of a bigger system.
Both controllers (including firmware) are quite different internally
(MST/FEC/DSC support, link training done by driver, additional commands, IRQ's
etc.) but they have similar register map, except for Framer/Streamer (which is
noticeably different), so they appear similar.

The following patches contain:
- Moving common code to drivers/gpu/drm/bridge/cdns-mhdp-common.* and
  modifying it a bit (mostly new prefixes for functions and data types) so it
  can be used by two, higher level, drivers.
- Modifying existing RockChip's DP driver to use the common code after changes
  made to it (use the new cdns_mhdp_device structure and new function names).
- Modifying DRM helpers a bit. Some are required for new driver, some are
  updates from DP 1.2 to 1.3 or 1.4.
- Adding documentation for device tree bindings.
- Adding preliminary Cadence DPI/DP bridge driver.

Some of the things that will be added later on include (but are not limited
to):
- DSC support
- FEC support
- HDCP support


Changes in v7:
- Overal code cleanup
- Patched memory leak after EDID read
- Fixed SPDX-License-Identifier tags
- Sorted includes
- In patch 4/6:
  Cleanup and fix in mhdp_transfer
  Replaced byteshifts with {put|get}_unaligned_be{32|24|16} (added 24bit one)
- In patch 5/6:
  Removed cdns_mhdp_mst_set_threshold (not needed anymore as HW does that)
  Updated cdns_mhdp_mst_set_rate_governing
  Replaced request_irq with devm_request_irq
  And then merged with 4/6 (as many changes in this patch altered the SST part)
- In patch 6/6:
  Fix in checking devm_phy_get result
  Updated bindings doc
  And then merged with 4/6 (as this should be in the driver in the first place)

Changes in v6:
- Added Reviewed-bys for already reviewed patches
- Dropped patch v5-0003 (that made dp_get_lane_status helper public)
- Added patch with MST support
- Added patch with Cadence SD0801 PHY init

Changes in v5:
- Fixed Kconfig in drm/rockchip again
- Moved cdn-dp-reg.h (cdns-mhdp-common.h) to include/drm/bridge instead of
    drivers/gpu/drm/bridge/
- Updated the mhdp_validate_cr function

Changes in v4:
- Fixed Kconfig in drm/rockchip
- Fixed Signed-offs
- dp_link_status() is no longer public since it's used only in drm_dp_helper.c
- Replaced EXTRA_CFLAGS with ccflags-y in drm/rockchip Makefile

Changes in v3:
- Corrected dt-bindings document
- Enabled some clocks at startup (since FW doesn't do that anymore).
- Changed Firmware file name to match the file on Linux Firmware repo.
- Added SST audio support
- Made common functions (in cdns-mhdp-common.*) public.

Changes in v2:
- Added actual description of what the patch contains, what is it for and
  what's going on here in general.
- New structure. Now we have one common low level driver + two high level
  drivers - one for RockChip with minimum changes and one, more general, for
  Cadence.
- Dropped some changes made to DRM helpers.
- Updated the device tree bindings document.


Damian Kos (1):
  drm/rockchip: prepare common code for cdns and rk dpi/dp driver

Quentin Schulz (3):
  drm/dp: fix link probing for devices supporting DP 1.4+
  dt-bindings: drm/bridge: Document Cadence MHDP bridge bindings
  drm: bridge: add support for Cadence MHDP DPI/DP bridge

 .../bindings/display/bridge/cdns,mhdp.txt     |   47 +
 drivers/gpu/drm/bridge/Kconfig                |    9 +
 drivers/gpu/drm/bridge/Makefile               |    3 +
 drivers/gpu/drm/bridge/cdns-mhdp-common.c     | 1103 ++++++++++++++
 drivers/gpu/drm/bridge/cdns-mhdp-mst.c        |  549 +++++++
 drivers/gpu/drm/bridge/cdns-mhdp.c            | 1349 +++++++++++++++++
 drivers/gpu/drm/bridge/cdns-mhdp.h            |  209 +++
 drivers/gpu/drm/drm_dp_helper.c               |   30 +-
 drivers/gpu/drm/rockchip/Kconfig              |    4 +-
 drivers/gpu/drm/rockchip/Makefile             |    2 +-
 drivers/gpu/drm/rockchip/cdn-dp-core.c        |  234 +--
 drivers/gpu/drm/rockchip/cdn-dp-core.h        |   43 +-
 drivers/gpu/drm/rockchip/cdn-dp-reg.c         |  969 ------------
 include/drm/bridge/cdns-mhdp-cbs.h            |   29 +
 .../drm/bridge/cdns-mhdp-common.h             |  176 ++-
 15 files changed, 3606 insertions(+), 1150 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/display/bridge/cdns,mhdp.txt
 create mode 100644 drivers/gpu/drm/bridge/cdns-mhdp-common.c
 create mode 100644 drivers/gpu/drm/bridge/cdns-mhdp-mst.c
 create mode 100644 drivers/gpu/drm/bridge/cdns-mhdp.c
 create mode 100644 drivers/gpu/drm/bridge/cdns-mhdp.h
 delete mode 100644 drivers/gpu/drm/rockchip/cdn-dp-reg.c
 create mode 100644 include/drm/bridge/cdns-mhdp-cbs.h
 rename drivers/gpu/drm/rockchip/cdn-dp-reg.h => include/drm/bridge/cdns-mhdp-common.h (77%)

-- 
2.17.1