iio: logic: Add ADSY1100 Apollo SOM Nyx RFFE controller

[mhennerich]

Summary

• New IIO driver adsy1100_nyx for the GPIO-driven RF front-end on the Analog Devices ADSY1100 Apollo SOM "Nyx" daughter board: per-channel DSA (0 .. -31.5 dB / 0.5 dB step), filter band selection (low_band / thru / x_band / ku_band), powerdown, and per-RX LNA bypass. Per-channel power-on defaults can be provided via output-channels (TX) / input-channels (RX) subnodes.
• DT binding schema + matching dt-bindings/iio/logic/adi,adsy1100-nyx.h header with the filter-mode enum macros.
• Overlay vu11p-ad9084-vpx-adsy1100-nyx.dtso wires up the 76 control GPIOs and includes a per-channel default template (values matching the driver built-in defaults: 0 dB / THRU / channel enabled / RX LNA bypassed). Base overlay adds a dormant adsy1100_nyx stub node.
• AD9084 device profile (.bin + .json) referenced by the overlay via DEVICE_PROFILE_NAME.
• adi_zynqmp_adsy1100_defconfig enables CONFIG_ADSY1100_NYX=y.

Test plan

• make ARCH=arm64 adi_zynqmp_adsy1100_defconfig keeps CONFIG_ADSY1100_NYX=y
• Driver builds clean for arm64 (drivers/iio/logic/adsy1100_nyx.o)
• Overlay compiles to dtbo (vu11p-ad9084-vpx-adsy1100-nyx.dtbo)
• make dt_binding_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/iio/logic/adi,adsy1100-nyx.yaml (run on a host with dtschema available — not run locally)
• Boot on a vu11p-ad9084-vpx + Nyx target: verify iio:device* exposes 4 IIO_VOLTAGE input + 4 output channels with hardwaregain, filter_mode/filter_mode_available, powerdown, and (RX only) bypass_amplifier_en attributes
• Toggle each control via sysfs and confirm corresponding GPIO transitions
• Verify probe-time defaults supplied through the DT subnodes are reflected in the initial sysfs values

[github-actions]

LLM review

This series adds the adi,adsy1100-nyx GPIO-driven RF front-end controller driver for the Analog Devices ADSY1100 Apollo SOM "Nyx" daughter board: DT binding, IIO platform driver, device-tree overlay, AD9084 device profile firmware, and defconfig entry.

run: 26163731542

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e871d3e71 - iio: logic: Add ADSY1100 Nyx RF front-end driver

Write-raw bug: fractional attenuations rejected for |val| >= 1

The write_raw handler incorrectly rejects any attenuation value with a non-zero integer part and a 0.5 dB fraction (e.g. -1.5 dB, -2.5 dB, ..., -31.5 dB).

The IIO core (__iio_str_to_fixpoint in drivers/iio/industrialio-core.c:884) encodes negative fractional dB values as val = -N, val2 = +500000 — the fractional component always carries the magnitude of the sub-integer portion, not its sign (the only exception is -0.5 dB where val=0, val2=-500000).

The current guard:

if (val > 0 || val2 > 0)   /* line 187 */
    return -EINVAL;

rejects -1.5 dB (val=-1, val2=+500000) because val2 > 0, so only -0.5 dB and integer dB steps are accepted. The DSA can encode half-dB steps (0..63 in units of 0.5 dB) so 31 of the 63 non-zero steps are unreachable from sysfs.

The fix follows the pattern used by drivers/iio/frequency/admfm2000.c:

if (val > 0 || (val == 0 && val2 > 0))
    return -EINVAL;

if (val < 0)
    millidB = (-val) * 1000 + val2 / 1000;
else
    millidB = (-val2) / 1000;

869b4c274 - dt-bindings: iio: logic: Add ADSY1100 Nyx RFFE controller

Wrong header path in description text

Lines 96 and 151 of the YAML binding reference:

<dt-bindings/iio/adi,adsy1100-nyx.h>

The header actually lives at include/dt-bindings/iio/logic/adi,adsy1100-nyx.h. The #include in the binding example (line 179) is already correct with the logic/ subdirectory; only the description strings are wrong.

CI warnings

The checkpatch warning "added, moved or deleted file(s), does MAINTAINERS need updating?" fires for the three new-file commits. No MAINTAINERS entry exists for drivers/iio/logic/adsy1100_nyx.c or the associated binding.

The "DT binding docs and includes should be a separate patch" warning is a false positive caused by running checkpatch on the combined series output; the binding commit (869b4c274) correctly contains only the YAML and header.

Verification data

• Compiled drivers/iio/logic/adsy1100_nyx.o for arm64 with gcc_aarch64 — clean.
• Validated adi,adsy1100-nyx.yaml with make dt_binding_check (dtschema 2024.9) — passes.
• Traced __iio_str_to_fixpoint() in drivers/iio/industrialio-core.c:884 to confirm IIO encoding of negative fractional dB.
• Cross-checked correct write_raw pattern against drivers/iio/frequency/admfm2000.c.
• Confirmed 76 GPIO entries in the overlay match ADSY1100_NYX_GPIO_COUNT.

Suggested patches

Apply the suggested patches with:

cd path/to/repository
export GITHUB_TOKEN=ghp_***
apply-patches --repo=analogdevicesinc/linux 26163731542

Install instructions

The following one-liner installs the script if not present already:

curl -fSsL "https://raw.githubusercontent.com/analogdevicesinc/doctools/refs/heads/main/ci/scripts/apply-patches.sh" \
     -o ~/.local/bin/apply-patches.sh && \
  grep -q "/apply-patches.sh" ~/.bashrc || echo "source ~/.local/bin/apply-patches.sh" >> $_ ; . $_

More information at AI Usage.