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

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 19 Oct 2026 21:00:31 -0300
Stephan Costa Barros <stephanbrrs8@gmail.com> wrote:

> 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.
> 
Definitely worth having a go to extend the existing driver.
If you run into major problems or unexpected complexity then
possibly come back to the separate one.

Jonathan

> Stephan