[PATCH v5 0/8] phy: rockchip-samsung-dcphy: Add the MIPI D-PHY receiver

[Jason Yang <jason98166@gmail.com>]

The Samsung MIPI D-/C-PHY block on RK3588 and RK3576 has a transmitter
for DSI and a receiver for CSI-2. Both can be used at the same time.

Mainline only supports the transmitter and models the block as a single
struct phy. The PHY core refcounts power_on() per struct phy, so the
receiver cannot be powered independently of it, and the single
devicetree cell selects the mode, so the provider cannot tell which of
the two a consumer refers to.

This series registers a struct phy for each of them, adds a second
devicetree cell with generic PHY_DIRECTION_TX and PHY_DIRECTION_RX
constants so that a consumer can select one of them, and implements the
D-PHY receiver. A single cell keeps referring to the transmitter, so
existing device trees are unaffected.

  1/8  adds PHY_DIRECTION_TX and PHY_DIRECTION_RX to the generic header
  2/8  allows a second cell in the rockchip,rk3588-mipi-dcphy binding
       to select the transmitter or the receiver
  3/8  moves the block-level setup to runtime resume
  4/8  names the transmitter helpers and ops (no functional change)
  5/8  registers the receiver's struct phy and takes the second cell
       in of_xlate()
  6/8  implements the D-PHY receiver bring-up
  7/8  switches the RK3588 DC-PHYs to two cells and lets DSI select
       the transmitter
  8/8  adds the MIPI CSI-2 receiver nodes on RK3588 and connects them
       to VICAP

Testing
=======

Tested on an RK3588 board, with a DSI panel and an IMX219 camera on
DCPHY0, and an LVDS panel behind a DSI-to-LVDS bridge on DCPHY1.

  - The transmitter and the receiver run at the same time: with 7/8
    and 8/8, both panels light from boot, and the camera stream is
    shown live on the DCPHY0 panel.
  - The two can be powered independently: the DCPHY0 panel is turned
    off and back on during a 1200-frame capture, and the capture
    completes.
  - The receiver does not need the transmitter: with dsi0 disabled,
    the camera alone brings the block up and streams, which relies
    on 3/8 moving the block-level setup to runtime resume.
  - Existing device trees keep working: with a single PHY_TYPE_DPHY
    cell in dsi0 as before 7/8, the DCPHY0 panel lights.

No WARNING, underflow, "Internal error" or Oops in dmesg in any of
these.

Not covered: the receiver of DCPHY1, the 3- and 4-lane receiver
paths, and RK3576.

The DSI panels only light with the U-Boot SPLL fix [1] applied:
without it the bootloader leaves the SPLL at its 351 MHz bootrom
default while the devicetree describes it as a 702 MHz fixed clock,
halving the rate of both DSI hosts. The receiver path is unaffected;
the camera captures exercise it independently.

[1] https://lore.kernel.org/u-boot/20260804002643.2308515-3-jonas@kwiboo.se/

---
Changes in v5:
- Rebase onto phy/next. The runtime PM fix this series applied on top
  of is now commit 261e84f9278f ("phy: rockchip-samsung-dcphy: Enable
  runtime PM at PHY core level"), so it is no longer carried here.
- 1/8: use PHY_DIRECTION_TX and PHY_DIRECTION_RX instead of
  PHY_TYPE_DSI and PHY_TYPE_CSI. (Michael)
- 2/8: use PHY_DIRECTION_* for the second cell and rewrite the
  description.
- Drop v4's 5/7: it has no benefit over the switch, and it moved a
  DC-PHY shared function into a D-PHY helper. (Michael)
- 5/8: rename protocol to direction in of_xlate() to follow 1/8.
- 6/8: use a switch in the receiver's power_on() and power_off(), as
  the transmitter does.
- New patches 7/8 and 8/8: switch the RK3588 DC-PHYs to two cells and
  add the MIPI CSI-2 receiver nodes.
- Link to v4: https://lore.kernel.org/r/20260821-dcphy-rx-v1-v4-0-f1797634233d@gmail.com

Changes in v4:
- Put the second cell back: the first cell selects the mode, the
  second the transmitter or the receiver.
- Drop the private use count and mutex; the runtime PM usage count
  does the same job.
- New patch 3/7: move the block-level setup to runtime resume.
- Split v3's 3/5 into 4/7 and 5/7.
- of_xlate() rejects a mix of D-PHY and C-PHY consumers.
- The runtime PM probe-order fix is now a separate patch [1] that this
  series applies on top of.
- Bryan O'Donoghue's Reviewed-by from v2 is not carried over; that
  patch was rewritten.
- Link to v3: https://lore.kernel.org/r/20260810-dcphy-rx-v1-v3-0-a2d25c29adfc@gmail.com

---
Jason Yang (8):
      dt-bindings: phy: Add PHY_DIRECTION_TX/RX definitions
      dt-bindings: phy: rockchip,rk3588-mipi-dcphy: Add a cell to select TX or RX
      phy: rockchip-samsung-dcphy: Move block-level setup to runtime resume
      phy: rockchip-samsung-dcphy: Name the transmitter helpers and ops
      phy: rockchip-samsung-dcphy: Add a second PHY for the receiver
      phy: rockchip-samsung-dcphy: Add MIPI D-PHY receiver support
      arm64: dts: rockchip: use two phy cells for the rk3588 mipi dcphys
      arm64: dts: rockchip: add mipi csi-2 receiver nodes for the dcphys on rk3588

 .../bindings/phy/rockchip,rk3588-mipi-dcphy.yaml   |  20 +-
 arch/arm64/boot/dts/rockchip/rk3588-base.dtsi      |  76 ++-
 drivers/phy/rockchip/phy-rockchip-samsung-dcphy.c  | 529 +++++++++++++++++++--
 include/dt-bindings/phy/phy.h                      |   3 +
 4 files changed, 580 insertions(+), 48 deletions(-)
---
base-commit: 8f56fdf3d8cb9f1dbdc93bf9ac816698aa6f70b7
change-id: 20260721-dcphy-rx-v1-9af57f3edfd9

Best regards,
--  
Jason Yang <jason98166@gmail.com>