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[0/4] media: rcar-csi2: Add D-PHY support for V4H

Message ID 20250510205534.4163066-1-niklas.soderlund+renesas@ragnatech.se
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Series media: rcar-csi2: Add D-PHY support for V4H | expand

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Niklas Söderlund May 10, 2025, 8:55 p.m. UTC 
Hello,

This series adds support for CSI-2 D-PHY reception on R-Car Gen4 V4H 
devices. Previously only C-PHY reception due to poor documentation and 
no hardware to test D-PHY on.

Later revisions of the datasheet (Rev.1.21) describes the start-up 
procedure in some detail, and we now have hardware to test on! The 
documentation however only sparsely documents the registers involved and 
instead mostly document magic values and an order to write them to 
register offsets without much documentation.

This series tries to in the extend possible to at least used named 
register and use formulas and lookup tables to make some sens of the 
magic values. Still most of them comes of a table of magic values in the 
datasheet.

Patch 1/4 clears up a unfortunate mix of the name mbps (mega bits per 
second) used in the D-PHY context and msps (mega symbols per second) 
used in the C-PHY context.

Patch 2/4 and 3/4 prepares for adding D-PHY support by cleaning up 
register names and an updated common startup procedure for V4H which 
have been revised in later versions of the datasheet since the initial 
C-PHY V4H support was added.

Finally patch 4/4 adds D-PHY support.

The work is to great extent at many different link speed and number of 
lanes. In 2-lane mode using an IMX219 and in 4-lane mode using IMX462 
sensors.

Niklas Söderlund (4):
  media: rcar-csi2: Clarify usage of mbps and msps
  media: rcar-csi2: Rework macros to access AFE lanes
  media: rcar-csi2: Update start procedure for V4H
  media: rcar-csi2: Add D-PHY support for V4H

 drivers/media/platform/renesas/rcar-csi2.c | 449 ++++++++++++++++++---
 1 file changed, 404 insertions(+), 45 deletions(-)