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
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