Re: [PATCH v4 0/3] nfc: st-nci: Fairphone 5 NFC bring-up (ST21NFCD)

[Luca Weiss]

Hi Kristian!

On Wed Sep 2, 2026 at 11:22 PM CEST, Kristian Brox wrote:
> This adds NFC on the Fairphone 5 (qcm6490). The board uses an ST21NFCD
> on I2C. That part speaks raw NCI; the current st-nci driver always
> wraps NDLC, so using st,st21nfcb-i2c leaves the adapter unusable.
>
> The series adds a st,st21nfcd compatible for the raw-NCI path and the
> Fairphone 5 DT node. Boards that already use st21nfcb / st21nfcc keep
> the NDLC path.
>
> Patches are against linux-nfc/for-next (Linux 7.3-rc1). Hardware test
> was on a Fairphone 5 running postmarketOS:
>
> - 7.1.2 sc7280, earlier raw-NCI modules: nfctool Powered: Yes;
>   initiator poll / neard: NTAG 215, NDEF URI read OK
> - 7.2.0-nfc-test+ (sc7280-mainline), this v4 st-nci as modules:
>   10x initiator poll finds Type 2 in 0.13-0.14 s, no
>   "unsupported ntf opcode 0xf02". Repeat poll with a Type 2 tag
>   in the field stays Powered: Yes. Empty-field poll SIGINT
>   (nfctool -p, no tag) also stays Powered: Yes.
>
> The ndlc: hexdumps are pr_debug. SIGINT during CORE_RESET (nfctool -0
> then Ctrl-C during -1) wedges stock nci core; that is not this series.
>
> ese-present and uicc-present follow the public schematic (NFC_SWP1/SWP2:
> SWP_SE to SIM1, SWP_UICC to SIM2). SE/HCE is not tested.
>
> CLK_REQ (GPIO 39) is omitted, as on Fairphone 6 NFC. VBAT and VDD_TX sit
> on VPH_PWR and are not modelled. VCC_UICC_IN (L4C) is not modelled;
> UICC SWP is untested.

Thanks for sending this revision!

Unfortunately I can still fairly easily reproduce to break scanning:

[  211.682211] nci: __nci_request: wait_for_completion_interruptible_timeout failed 0
[  211.682246] nci: nci_start_poll: failed to set local general bytes
[  224.483009] nci: __nci_request: wait_for_completion_interruptible_timeout failed 0
[  224.483033] nci: nci_start_poll: failed to set local general bytes

I enabled polling with neard, scanned the tag a bunch of time. Then
disable polling, and afterwards the errors above appeared and starting
polling again does not work anymore - until I reboot.

In fact, I can reproduce this just be enabling polling, disabling
polling and enabling polling again. No need to scan a tag inbetween.

Can you please share how you've been testing these patches?

Regards
Luca

>
> Signed-off-by: Kristian Brox <isyourbrainfoss@xxxxxxxxx>
> ---
> Link to v3:
> https://lore.kernel.org/oe-linux-nfc/20260820-fp5-st21nfcd-v3-v3-0-5ee0a7f44d04@xxxxxxxxx/
>
> Changes in v4:
> - Driver: consume ST proprietary RF NTF 0xf02 (Luca)
> - Driver: set raw_nci before nci_register_device (Sashiko / David)
> - Driver: enable vdd-io and SYS_CLK before driving reset
> - Driver: keep named i2c/acpi id initializers; do not add trailing
>   commas on existing of_match entries (David)
> - Driver: reset pulse uses gpiod_is_active_low so new DT can be
>   GPIO_ACTIVE_LOW without breaking old nfcb DTS (Krzysztof)
> - Binding: ST21NFCD is not I2C-only (data brief lists SPI); do not
>   put st,st21nfcd in the I2C-only spi-max-frequency:false enum
> - Binding: SPI $ref only in the non-I2C else (not a global allOf item)
> - Binding: clocks/vdd-io-supply on the existing I2C example; drop the
>   extra example (Krzysztof)
> - DTS: reset-gpios GPIO_ACTIVE_LOW (Krzysztof). Physical GPIO 38 HIGH
>   is the run level. Konrad R-b not carried (polarity changed).
>
> Changes in v3:
> - Binding: new compatible is a different ST part (not a driver-sharing note)
> - Binding: drop NDLC/raw-NCI description on compatible
> - Binding example uses interrupts-extended
> - DTS: one nfc_default pinctrl group, pins sorted, no output-high
> - Fresh series (not a reply to v1/v2)
>
> Changes in v2:
> - Compatible is st,st21nfcd (no -i2c suffix)
> - Sent without PGP/MIME
> - DTS: interrupts-extended and pinctrl for IRQ/reset
> - DTS: ese-present / uicc-present (schematic)
> - DTS: SYS_CLK from LN_BB_CLK2, VPS_IO from L18B
> - Binding: optional clocks and vdd-io-supply
> - Driver: optional clk / vdd-io enable
>
> ---
> Kristian Brox (3):
>       dt-bindings: net: nfc: add st,st21nfcd
>       nfc: st-nci: add raw NCI path for ST21NFCD
>       arm64: dts: qcom: qcm6490-fairphone-fp5: add ST21NFCD NFC
>
>  .../devicetree/bindings/net/nfc/st,st-nci.yaml     | 49 +++++++++----
>  arch/arm64/boot/dts/qcom/qcm6490-fairphone-fp5.dts | 34 ++++++++-
>  drivers/nfc/st-nci/core.c                          | 22 ++++++
>  drivers/nfc/st-nci/i2c.c                           | 82 ++++++++++++++++++++--
>  drivers/nfc/st-nci/ndlc.c                          | 27 +++++--
>  drivers/nfc/st-nci/ndlc.h                          |  5 +-
>  drivers/nfc/st-nci/se.c                            |  3 +
>  drivers/nfc/st-nci/spi.c                           |  2 +-
>  drivers/nfc/st-nci/st-nci.h                        |  2 +
>  9 files changed, 197 insertions(+), 29 deletions(-)
> ---
> base-commit: cee9395acd8043be0644b25c34bfa86623f2b935
> change-id: 20260902-fp5-st21nfcd-v4-1685be1d7c52
>
> Best regards,
> --  
> Kristian Brox <isyourbrainfoss@xxxxxxxxx>