Hi Linus!

I like this patch.

I am glad!

Maybe a small paragraph first saying what this is, the usecase (feel
free to steal, rewrite etc):

The sloppy logic analyzer will utilize a few GPIO lines in input mode
on a system to rapidly sample these digital lines, which will, if the
Nyquist criteria is met, result in a time series log with approximate
waveforms as they appeared on these lines.

One way to use it is to analyze external traffic connected to these
GPIO lines with wires (i.e. digital probes), acting as a common logic
analyzer.

Well, frankly, with the driver depending on EXPERT, this paragraph seems
a tad superfluous to me. But as it came for free and won't hurt, I took
the liberty to add this to the beginning of the documentation.

Another thing it can do is to snoop on on-chip peripherals if the I/O
cells of these peripherals can be used in GPIO input mode at the same
time as they are being used as inputs or outputs for the peripheral,
for example it would be possible to scale down the speed of a certain
MMC controller and snoop the traffic between the MMC controller and
the SD card by the sloppy logic analyzer. In the pin control subsystem
such pin controllers are called "non-strict": a certain pin can be
used with a certain peripheral and as a GPIO input line at the same
time.

Thanks for pointing out the 'strict' mode. I actually did snoop pins
muxed to I2C but I had to use a gpiolib hack for it assuming this was
not supported otherwise. Now, I have a one-liner for the Renesas pinctrl
driver which makes things work as well. I will work this out with Geert
hopefully. Would be really great to have this feature without my hack!

That being said, the paragraph above is a bit too long for my taste,
I'll see if I can make it more concise. But it should be there, yes.

Thanks for your support!

Happy hacking,

   Wolfram