[PATCH v5 0/6] nfc: s3fwrn5: support the S3NRN4V variant

[Jorijn van der Graaf <jorijnvdgraaf@catcrafts.net>]

This adds support for the Samsung S3NRN4V, a later part in the Samsung
NCI NFC controller line the s3fwrn5 driver covers, found e.g. on the
Fairphone 6 (SM7635).

The S3NRN4V differs from the already-supported parts in three ways:
it ships with working firmware, and its bootloader reports a hardware
version the driver has no flash base address for (so the firmware
download step is skipped); it loads its RF calibration data through
a different proprietary command (DUAL_OPTION); and its reference
clock speed is set with the single-byte FW_CFG form the vendor HAL
uses on this generation.

Patches 1-2 are preparatory cleanups from the v2 review; patch 3 adds
the compatible to the binding and documents the PVDD supply; patch 4
makes the driver enable that supply; patch 5 implements the variant;
patch 6 adds the Fairphone 6 board nodes -- included so the hardware
can be tested, per David's v2 request; it depends on patch 3 and is
expected to be picked up via the qcom tree (linux-arm-msm) once the
binding has landed.

Tested on a Fairphone 6 running a milos-mainline kernel: reader mode
polls and reads ISO 14443-4 tags reliably, from a fresh boot and
across driver reloads, with the calibration files present and also
absent (the chip keeps its stored calibration and still reads). The
v5 changes were re-verified on the device: tag reads, with the
version-gate skip taking the restructured exit path. The test kernel
is v7.1.2-based; its net/nfc differs from this base only in the UART
transport (nci/uart.c), which this driver does not use.

David, the calibration scheme follows our v2 exchange: fixed
chip-scoped paths, with a DT table selector deferred until a second
table set exists. If you'd rather have the selector now
(samsung,calibration-variant, or the generic firmware-name), say so
and the next revision will add it.

The two questions we put to Luca in the v2 thread (calibration-table
variance, linux-firmware submission) are still open; nothing here
depends on them.

Changes in v5:
 - Collect Krzysztof's Reviewed-by on patches 1 and 3.
 - Patch 4: drop the redundant regulator-framework sentence from the
   commit message and state why the uart phy is not converted
   (Krzysztof).
 - Patch 5: restructure the exit labels so failures before the
   allocation no longer pass through kvfree(), drop the
   update-announcement print, and log success at dev_dbg() (all
   Krzysztof).
 - Rebase onto the nfc tree's current for-next, which was rebased
   since v4 (the nci parse-hardening and data.c commits v4's cover
   referenced are no longer in for-next after the rebase); patch 1's
   referenced commit id updated to the rebased tree (777fd2dab446,
   was 9739e07fdb29).

Changes in v4 (full list in the lore thread):
 - Drop clk-req-gpios and the driver's clock-gating machinery (A/B
   tested as functionless) and reference the buffer the chip is
   wired to (RPMH_LN_BB_CLK2 -- Luca; verified load-bearing).
 - New patch 4 consuming the binding's pvdd-supply.
 - FW_CFG from the ->init hook and the DUAL_OPTION upload
   version-gated on GET_VER, both matching the vendor stack; board
   DTS style (Konrad).

v4: https://lore.kernel.org/20260807021001.239389-1-jorijnvdgraaf@catcrafts.net
v3: https://lore.kernel.org/20260726222405.153008-1-jorijnvdgraaf@catcrafts.net
v2: https://lore.kernel.org/20260705190621.128257-1-jorijnvdgraaf@catcrafts.net
v1: https://lore.kernel.org/20260703202601.78563-1-jorijnvdgraaf@catcrafts.net

Jorijn van der Graaf (6):
  nfc: s3fwrn5: drop of_match_ptr() from the I2C driver
  nfc: s3fwrn5: use the "s3fwrn5_i2c" string literal directly
  dt-bindings: net: nfc: samsung,s3fwrn5: add the S3NRN4V
  nfc: s3fwrn5: enable the PVDD supply
  nfc: s3fwrn5: support the S3NRN4V variant
  arm64: dts: qcom: milos-fairphone-fp6: Add NFC

 .../bindings/net/nfc/samsung,s3fwrn5.yaml     |  19 +-
 .../boot/dts/qcom/milos-fairphone-fp6.dts     |  33 +++-
 drivers/nfc/s3fwrn5/core.c                    |  34 +++-
 drivers/nfc/s3fwrn5/i2c.c                     |  26 ++-
 drivers/nfc/s3fwrn5/nci.c                     | 178 +++++++++++++++++-
 drivers/nfc/s3fwrn5/nci.h                     |  23 ++-
 drivers/nfc/s3fwrn5/s3fwrn5.h                 |  14 +-
 drivers/nfc/s3fwrn5/uart.c                    |   2 +-
 8 files changed, 313 insertions(+), 16 deletions(-)


base-commit: 9f69d05b5a85c417c73fa2d5c7a2d507ac81cf4b
-- 
2.55.0