Re: [PATCH 08/14] mfd: remove unused aat2870 driver

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 10 Sep 2026 20:14:15 +0200
"Arnd Bergmann" <arnd@arndb.de> wrote:

> On Thu, Sep 10, 2026, at 18:40, Svyatoslav Ryhel wrote:
> > __ 
> > Hello Arnd! May you please spare AAT2870 from being removed? I have a 
> > device which uses aat2870 (LG Optimus 2X P990 Tegra 2, not upstreamed 
> > yet, but in process as well) and atm I am working on converting this 
> > driver to use OF. Thank you!  
> 
> Sure, I have removed this patch from my series now.
> 
> > P. S. If you are planning to remove more old drivers, please CC me in 
> > since I may be interested in some additional driver upgrades for 
> > devices I own.  
> 
> Please have a look at
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/soc/soc.git/log/?h=board-remove-7.3
> 
> I tried to be careful about figuring out exactly which drivers are
> unused, but I'm sure there are still a few false positive and false
> negative ones in there. I've added the current list of driver files below,
> let me know if you see something that shouldn't be there.
Hi Arnd

For I2C and SPI at least, there doesn't need to be explicit
device tree support as long as they have defaults when platform
data isn't there. Those two buses will happily bind based on
a dt-compatible and their i2c_device_id or spi_device_id tables
for example.

So unless they fail to probe (some might?) we don't have
a clear signal on whether they are in use via DT or not.

For vast majority of IIO drivers we don't have an upstream
DTS as there is no clear motivation for anyone to upstream
the dts for a random industrial control board or similar.

> drivers/iio/adc/ad7266.c
No to dropping this.

Has fallbacks and should bind just fine  No one ever
bothered adding an of_device_id table because it isn't
needed. Fine to rip out the platform data support as nothing is
using that.

This is a production part that is likely being used in new designs.

> drivers/iio/adc/ad7791.c
No to dropping this one.

I'm fine with ripping out the platform data but this again
has defaults and may well be in use via DT. Antoniu from
Analog was doing some cleanup on this recently so I'd guess
they probably still at least somewhat care and some of the
supported parts are still in production (e.g. the AD7788)

> drivers/iio/adc/ad7793.c
Maybe. Analog devices ack needed.

Production part but this one indeed fails to probe.  Analog
folk, do you want to fix this one up?

> drivers/iio/adc/ad7887.c
No to dropping this.

Production part - should work fine with defaults in driver.
Could like the others drop the platform data handling.

> drivers/iio/adc/lp8788_adc.c
Probably

Sub driver of an MFD.  I'm fine with that going if we know
the mfd is no longer in use.

> drivers/iio/adc/lpc18xx_adc.c
> drivers/iio/dac/lpc18xx_dac.c
Probably

Likewise these two.

> drivers/iio/frequency/ad9523.c
Maybe. Analog Devices ack needed.

Fails to probe without platform data and marked not recomended
for new designs. If we get an Ack from Analog devices folk
I'm fine with this one going away.

Jonathan