Hi, On Wed, Dec 14, 2016 at 11:11:19PM +0100, Jernej Škrabec wrote: > > > While I took Rockchip HDMI code for reference, it can't be easily reused. > > > First of, it uses DT nodes. I guess I could write DT binding or modify > > > existing driver to work without it. > > > > Like we discussed in the other part of the thread, I think the latter > > would be easier to deal with. > > I forgot to mention that it also uses driver model. The way I would go with > this is to split out common code to dwc_hdmi.c and have platform dependant > drivers for Rockchip, Allwinner, etc. Basically the same way as it is done in > Linux.
That sounds reasonable. > > > Thirdly, and in my opinion most annoying, Rockchip driver uses 32 > > > bit aligned registers, but H3 does not. This also means a lot of > > > work to make it more generic. > > > > How does Linux deal with that? Would just using some kind of accessors > > that would abstract that away from the driver help, or is it more > > complicated? > > Yes, Linux driver checks "reg-io-width" property and selects accessors > accordingly. I suppose I could do similar, save function pointer in a driver > private data. I suppose it is ok that platform specific code initializes this > private data? Something like passing a flag stored in the platform data (and/or read from DT for the relevant cases) to a generic accessor would also be a solution, without the need for everyone to implement its accessors. > > > Actually, H3 is more similar to i.MX6 HDMI in this regard, but > > > driver's code is scattered throughout multiple files (search for > > > mxc_hdmi.h inclusion). It is certainly doable, but it will take much > > > more time. Basically, U-Boot already has two drivers for DWC HDMI > > > and with this patch it will get third. Merging all three > > > implementations into one would be very tedious, but very desirable > > > goal. I must state that I didn't really try to understand i.MX6 HDMI > > > code at all, so I don't now how hard it would be to pull it out. > > > > I'm not sure that merging a third and saying that it would be up to > > the fourth to do the work is reasonable. It's just hiding an issue > > under the carpet, but I don't see how it will be easier for the next > > person to work on that. Quite the opposite actually. > > True. I wonder if Renesas already prepared U-Boot DWC HDMI driver... > > Do you think it makes sense to put all files related to Allwinner > video drivers to sunxi subfolder? There will be at least 4 .c files > according to my plan and even more in the future (at least for TV > out driver). On principle, I don't see anything wrong with that. Thanks! Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
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