Re: [PATCH 0/2] iio: adc: add TI ADS1299

[Stephan Costa Barros <stephanbrrs8@gmail.com>]

On Mon, Oct 19, 2026 at 01:16:58PM +0300, Andy Shevchenko wrote:
> On Sun, Oct 18, 2026 at 09:12:45PM -0300, Stephan Costa Barros wrote:

[...]

> > A question on structure. The driver started from ti-ads1298.c, and in
> > this subset the two are close.

[...]

> Okay, I think you can try to rework this as a series on top of the existing
> code. I can't easily see if the above difference warrants a brand new driver.

Thanks, Andy. I'll do that for v2: first prepare ti-ads1298 for more
than one family (chip info for the gain table, the data rates and the
reference), then add the ADS1299 to it, with its compatibles in
ti,ads1298.yaml instead of a new binding.

Some background: this comes from my undergraduate thesis. The project
first planned a driver written from scratch; I then found ti-ads1298 and
built on it instead. Beyond what ti-ads1298 does today, the out-of-tree
driver that came out of it sets the gain of each channel, timestamps
each buffered sample, reports lead-off as IIO_EV_TYPE_FAULT /
IIO_EV_DIR_FAULT_OPENWIRE events, routes the internal test signal and
shorted inputs, reads the supply monitors and the temperature sensor,
switches SRB1 and SRB2, and runs a self test at probe; all of that is
tested on an ADS1299. The bias drive, GPIO1-4 as a gpiochip, the CLK
output, PWDN and suspend are written but not tested yet.

For mainline I cut this down to the generic ABI. The rest can follow as
separate series on top of ti-ads1298, where most of it applies to the
ADS1298 as well; only SRB1 and SRB2 are ADS1299-specific.

The automated review of this version also pointed at issues that the
new driver inherited from ti-ads1298 too.

I had missed Md Shofiqul Islam's series when I sent this one, and found
it only now: "[PATCH v2 0/2] iio: adc: ti-ads1298: add ADS1298/ADS1299
driver", sent on 6 July 2026 and reviewed by Jonathan on 11 July. Md,
are you still working on it? If not, I would like to take it on,
following Jonathan's review there (per-chip match data, the reference
voltage and the ID register), and I can test it on hardware: an ADS1299
with DRDY as an interrupt.

Jonathan, if you would rather keep a separate driver, please let me
know before I start.

Stephan