Re: [RFC PATCH 0/3] iio: adc: Add support for TI ADS1120 ADC

[Ajith Anandhan <ajithanandhan0406@gmail.com>]

On 10/31/25 2:07 PM, Andy Shevchenko wrote:
> On Thu, Oct 30, 2025 at 10:04:08PM +0530, Ajith Anandhan wrote:
>> This RFC patch series adds support for the Texas Instruments ADS1120,
>> a precision 16-bit delta-sigma ADC with SPI interface.
>>
>> The driver provides:
>> - 4 single-ended voltage input channels
>> - Programmable gain amplifier (1 to 128)
>> - Configurable data rates (20 to 1000 SPS)
>> - Single-shot conversion mode
>>
>> I'm looking for feedback on:
>> 1. The implementation approach for single-shot conversions
>> 2. Any other suggestions for improvement
>>
>> Datasheet: https://www.ti.com/lit/gpn/ads1120
> The cover letter missed to answer the Q: Why a new driver? Have you checked the
> existing drivers? Do we have a similar enough one that may be extended to
> support this chip?
>
Hi Andy,

Thank you for the feedback.

I evaluated the following existing driver before creating a new one:

ads124s08.c - TI ADS124S08

- This is the closest match (both are delta-sigma, SPI-based)

- However, significant differences exist:

     * Different register layout (ADS124S08 has more registers)

     * Different command set ADS124S08 has built-in MUX for differential 
inputs

     * Different register addressing and bit fields and conversion 
timing and data retrieval.

would require extensive conditional code paths that might reduce 
maintainability for both devices. A separate, focused driver seemed cleaner.

BR,
Ajith Anandhan.