[PATCH v3 phy-next 0/8] RCW override for 10G Lynx dynamic protocol reconfiguration

[Vladimir Oltean <vladimir.oltean@nxp.com>]

Previous set "New Generic PHY driver for Lynx 10G SerDes":
https://lore.kernel.org/linux-phy/20260610151952.2141019-1-vladimir.oltean@nxp.com/
introduced the 10G Lynx SerDes driver with a reduced functionality set.
Namely, only minor protocol changes are supported (1GbE <-> 2.5GbE).
The major protocol changes need a procedure named RCW override,
explained in more detail in commits 6/8 and 7/8.

This series adds kernel and device tree binding support for RCW
override, completing the SerDes PHY driver functionality.

Two components are involved:
- drivers/soc/fsl/guts.c (binding is fsl,layerscape-dcfg.yaml) - Device
  Configuration Unit, this is API provider for the SerDes driver to
  request RCW override depending on SoC
- drivers/phy/freescale/phy-fsl-lynx-10g.c - SerDes PHY driver, this is
  API consumer

The guts driver probes on DCFG blocks from multiple Freescale SoC
generations:
- MPC85xx, BSC and QorIQ (PowerPC) are all covered by the
  Documentation/devicetree/bindings/soc/fsl/guts.txt schema
- Layerscape (Arm) is covered by
  Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-dcfg.yaml

It is ultimately the same hardware block, just that (from what I can
tell) the Layerscape nodes are also compatible with syscon, and PowerPC
aren't.

RCW override has only been validated on select Layerscape SoCs, so
converting guts.txt to a PowerPC schema is out of scope for this
series - we don't even touch that (just in case it gets asked).

Using syscon to map the DCFG_DCSR register block in the Lynx SerDes
driver instead of creating this guts <-> lynx API was considered, but
because the RCW procedure is SoC-specific, it was ruled out for
polluting the SerDes driver. The guts driver is all about SoC awareness
anyway, and it offers some abstraction of all the gory details.

Changes since v2:
- fix error handling in fsl_guts_init() and make sure that all newly
  introduced RCW override API functions fail if fsl_guts_init() failed.
- replace __bf_shf() use with __ffs()
- use read_poll_timeout_atomic() in fsl_guts_rcw_rmw() to clarify that
  DCFG_DCSR writes are supposed to reflect back in DCFG_CCSR
- only operate on lanes on which fsl_guts_lane_init() was called in
  ls2088a_serdes_init_rcwcr()
- put parentheses around (lane) in LS1088A_RCWSR29_SRDS_PRTCL_S1_LNn()
  and LS1088A_RCWSR30_SRDS_PRTCL_S2_LNn() macro expressions

v2 at:
https://lore.kernel.org/linux-phy/20260612210859.266759-8-vladimir.oltean@nxp.com/

Changes since v1:
- add Conor's review tag on 6/8
- update email addresses of DT maintainers
- drop DT maintainers from explicit CC on patch 7/8
- keep devicetree@vger.kernel.org CCed on entire series
- include missing <linux/bitfield.h> in patch 7/8
- namespace SRDS_PRTCL values for LS1046A and LS1088A, even if they are
  the same. For LS1028A (not covered here) they are not.
- prefix SRDS_CLK_SEL_{GMII,XGMII} with LS2088A_
- reorder alphanumerically (LS1046A should come before LS1088A)

Change logs also in individual patches.

v1 at:
https://lore.kernel.org/linux-phy/20260611193940.44416-1-vladimir.oltean@nxp.com/

Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Rob Herring <robh@kernel.org>

Ioana Ciornei (5):
  soc: fsl: guts: use a macro to encode the DCFG CCSR space
  soc: fsl: guts: add a global structure to hold state
  soc: fsl: guts: add a central fsl_guts_read() function
  soc: fsl: guts: make it easier to determine on which SoC we are
    running
  soc: fsl: guts: implement the RCW override procedure

Vladimir Oltean (3):
  soc: fsl: guts: make fsl_soc_data available after fsl_guts_init()
  dt-bindings: fsl: layerscape-dcfg: define DCFG_DCSR region
  phy: lynx-10g: use RCW override procedure for dynamic protocol change

 .../bindings/soc/fsl/fsl,layerscape-dcfg.yaml |  15 +-
 drivers/phy/freescale/Kconfig                 |   1 +
 drivers/phy/freescale/phy-fsl-lynx-10g.c      |  24 +-
 drivers/soc/fsl/guts.c                        | 438 ++++++++++++++++--
 include/linux/fsl/guts.h                      |  20 +-
 5 files changed, 459 insertions(+), 39 deletions(-)

-- 
2.34.1