Messages in this thread | | | From | "Rymarkiewicz, WaldemarX" <> | Subject | RE: [linux-nfc] [PATCH RFC] nfc: add a driver for pn532 connected on uart | Date | Fri, 23 Aug 2013 09:47:57 +0000 |
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Hi,
>Yes, I know that and I explicitly mentioned that. I had to get this chip working >somehow and I had to begin somewhere. The pn533 driver is really very hard >to understand with it's massive use of nested callbacks, workqueues and >usb urbs. So I took the approach to try to understand what happens while modifying >and would then later factor out what both drivers have in common. >The other way is understanding the code first and then decide what would be needed for > both chips, factor that out and then write the pn532 uart specific stuff. And this uart stuff >is a pain itself in linux. This way seemed much harder to me, > especially as I have no pn533 device to test which things will break.
I understand. It took me some time to understand this too. Now, it's even harder after adding protocol ops, but still is pretty well layered.
> I suggest to separate transport layer from the core in pn533 and add > support for uart and usb separately. This is exactly what I've planned > while changing pn533 to support acr122 device. >> Yes, I agree with you this should be done. I'll expect it to be challenging >> but based on my previous work this could be doable.
Be sure there will be pitfalls separating transport. I've already experienced some of them adding support for acr122.
>> I'll look into that in my next free timeslot. I'll not be able to do that in the next two months. >>Sorry.
No worries. I know this pain :)
Thanks, /Waldek
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