Re: [PATCH v5 00/20] iio: adc: Add AD7768/AD7768-4 ADC driver support

[Bartosz Golaszewski]

On Fri, 28 Aug 2026 17:30:23 +0200, Janani Sunil <janani.sunil@xxxxxxxxxx> said:
> Add support for Analog Devices AD7768 and AD7768-4, 24-bit simultaneous
> sampling Sigma-Delta ADCs with automatic power mode selection.
>
> Datasheet:
> https://www.analog.com/media/en/technical-documentation/data-sheets/ad7768-ad7768-4.pdf
>
> **Device Overview:**
> The AD7768 is an 8-channel, 24-bit simultaneous sampling ADC. The
> AD7768-4 is a 4-channel variant. Both support configurable power modes,
> programmable decimation filters, and a high-speed serial interface with
> 1, 2, 4, or 8 data output lines. Per-channel offset, gain, and phase
> calibration registers are available.
>
> **Features Implemented:**
> - Support for AD7768 (8-channel) and AD7768-4 (4-channel) via device
>   match data.
> - Automatic low-noise power mode selection (fast, median, low power)
>   with associated decimation rate and output data rate tables.
> - Per-channel offset, gain, and conversion delay via IIO attributes.
> - SPI communication with custom regmap bus for the device's protocol.
> - IIO backend integration with adi-axi-adc for high-speed data capture.
> - CRC data integrity verification over the serial interface.
> - GPIO auxiliary driver to expose the 5 on-chip GPIO pins.
> - VCM common-mode output exposed through the regulator framework, with
>   runtime PM management while the output is enabled.
>
> **Patch Summary:**
> 1. Initialize the AXI ADC state mutex.
> 2. Add the AD7768 and AD7768-4 devicetree binding.
> 3. Add the IIO backend CRC operation.
> 4. Implement CRC control in the AXI ADC backend.
> 5. Add core AD7768 and AD7768-4 capture support.
> 6. Validate the master clock rate.
> 7. Add the power-mode configuration helper.
> 8. Derive output data rates and the data-clock divider.
> 9. Configure enabled channels across two sampling profiles.
> 10. Expose per-channel sampling-frequency controls.
> 11. Expose per-channel filter controls.
> 12. Wait for active digital filters to settle.
> 13. Add per-channel offset and gain calibration controls.
> 14. Add per-channel conversion delay.
> 15. Expose the VCM output through the regulator framework.
> 16. Register the GPIO auxiliary device from the parent driver.
> 17. Use regmap_test_bits() for single-bit gpio-regmap reads.
> 18. Add optional runtime PM support to gpio-regmap.
> 19. Add the AD7768 GPIO auxiliary driver.
> 20. Add driver documentation.

What is the merge strategy here between iio and GPIO trees? Can patches
17-18 go through an immutable branch in the GPIO tree that would be merged
into the iio tree?

Bart