[PATCH v2 0/9] media: camss: add SM8750 support

[Qianhui Xu]

This series adds camera capture support for the Qualcomm SM8750 SoC
(camera subsystem block with three full and two lite CSIDs, six CSIPHY,
three full and two lite VFEs and three CSITPGs).  It was developed on a
Lenovo TB322FC (Y700 Gen4 tablet) and both of its sensors (rear s5kjns,
front gc08a8) capture at full resolution and 30 fps with it, through
libcamera.

The block is close to the SM8650 one, but the capture interrupts move from
the VFE to the CSID: the VFE of this generation has no useful interrupt
sources, and the CSID reports RDI buffer done, register update completion
and CAMIF start-of-frame per CSI2 stream.  That drives the two structural
changes in the series:

 - camss-csid-980.c adds the CSID registers of this generation, with the
   full and the lite variant; the full one splits the register update into
   separate RUP and AUP commands that need an extra trigger write.

 - patches 4 and 5 keep the "add the generation" and "report frame starts
   from the CSID" parts apart.  The latter is the architectural change:
   frame start moves to the CSID, V4L2_EVENT_FRAME_SYNC is raised from
   there, the sequence number is only incremented on a frame start, and a
   buffer whose frame never started is reported with
   VB2_BUF_STATE_ERROR instead of silently being numbered.  An SOF can
   also arrive after an as-yet unhandled completion, so the EOF and SOF
   timestamps are compared and the completion is reported first in that
   case.  Generations that still report frame starts through the VFE are
   unaffected: the new vfe_hw_ops callback is only provided by the VFE
   implementations that need it.

Patches 6 and 7 are generic video-node fixes the newer write master needs:
a buffer payload has to be physically contiguous because the frame
increment registers describe one linear range, and a start that fails
halfway must stop the subdevices already started.

The CSIPHY 2.4.0 lane values in patch 2 are the ones the vendor CSIPHY
2.4.0 driver uses for the two-phase variant of this PHY: address, mask and
parameter type match for all 103 entries and the data byte for 99, the
four remaining ones being the SKEW_CAL data bytes, which are left at the
vendor value.  The three-phase variant of the same PHY uses a different
address layout, so its table cannot be reused here.

Not included on purpose, to keep this series reviewable: the CCI/I2C
control path of this platform, the CSID to VFE instance pairing and the
repeated RUP on the initial buffers.  Those are being prepared separately.

Patch 9 describes the block in the SoC dtsi, so that dtbs_check exercises
the binding together with the node; the node is left disabled and boards
enable it on top.

Changes in v2 (addressing the automated Sashiko review of v1):
 - csid 980: DT_ID in CSID_RDI_CFG0 must be derived from the RDI port, not
   from the (always zero here) virtual channel; deriving it from the VC
   gave every RDI the same internal CID and broke streaming on RDI>0.
   This mirrors the fix already made for CSID gen3.
 - csid 980: unmask INFO_RUP_DONE in CSID_CSI2_RDIN_IRQ_MASK, as the
   vendor driver does, so the software register-update shadow is cleared
   when the hardware consumes an update.
 - vfe: clear output->frame_started once a completed buffer consumed it,
   and avoid the unsigned underflow of output->sequence - 1 when the very
   first buffer completes before any start-of-frame; the "buffer before
   SOF" error is now detected on every frame, not only the first.
 - vfe: return -ENOIOCTLCMD from subscribe_event and drop the explicit
   unsubscribe_event op, so generations without frame_start report a
   consistent -ENOIOCTLCMD for the event ioctls instead of a mix of
   -EINVAL and success.
 - dt-bindings: fix the sub-block counts in the commit message (three full
   and two lite CSIDs, three full and two lite VFEs) to match the schema.


Qianhui Xu (9):
  dt-bindings: media: add the Qualcomm SM8750 camera subsystem
  media: camss: csiphy: add CSIPHY 2.4.0 lane settings for SM8750
  media: camss: csid: unwind the power-on path through a single error
    label
  media: camss: csid: add the 980 generation
  media: camss: csid: report frame starts from CSID
  media: camss: video: check that a buffer is DMA contiguous and add a
    prepare hook
  media: camss: video: stop the subdevices already started when a start
    fails
  media: camss: vfe: add the gen4 block and SM8750 camera subsystem
  arm64: dts: qcom: sm8750: add the camera subsystem

 .../bindings/media/qcom,sm8750-camss.yaml     | 435 ++++++++++++++++
 arch/arm64/boot/dts/qcom/sm8750.dtsi          | 179 +++++++
 drivers/media/platform/qcom/camss/Makefile    |   2 +
 .../platform/qcom/camss/camss-csid-980.c      | 470 ++++++++++++++++++
 .../media/platform/qcom/camss/camss-csid.c    |  45 +-
 .../media/platform/qcom/camss/camss-csid.h    |   3 +
 .../qcom/camss/camss-csiphy-3ph-1-0.c         | 124 +++++
 .../platform/qcom/camss/camss-vfe-gen4.c      | 212 ++++++++
 drivers/media/platform/qcom/camss/camss-vfe.c |  74 ++-
 drivers/media/platform/qcom/camss/camss-vfe.h |   5 +
 .../media/platform/qcom/camss/camss-video.c   |  78 +--
 .../media/platform/qcom/camss/camss-video.h   |   1 +
 drivers/media/platform/qcom/camss/camss.c     | 369 ++++++++++++++
 drivers/media/platform/qcom/camss/camss.h     |   2 +
 14 files changed, 1938 insertions(+), 61 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/media/qcom,sm8750-camss.yaml
 create mode 100644 drivers/media/platform/qcom/camss/camss-csid-980.c
 create mode 100644 drivers/media/platform/qcom/camss/camss-vfe-gen4.c