On Mon, 2004-10-11 at 19:44, Lothar Wassmann wrote: > > 2) I now know the meaning of Fld, FExtrt etc. but these are defined in > > header file "bitfield.h", which is only available for certain arm-based > > archs. You use them to create a proper PTD structure. This was one of my > > problems (creating a proper PTD), and I really like your way, but I > > cannot use it on an i386 arch. Now apart from that, this is a very > > platform-specific solution, so we should really come up with a more > > general way of doing it. Any ideas? (or opinions as to why my > > assumptions are wrong. I really am new to all of this, so I might be > > missing something...) > > > These are generic macros that could be used on any platform. Why they > are located in include/asm-arm/arch-pxa/ I don't know. But we could > achieve the same without using those macros. > OK, that's good news, but I have the same problem with asm/hardware.h asm/mach-types.h and asm/arch/dma.h . This whole thing is very arm-specific... So in my i386 platform, it doesn't compile. Anyway, I guess I don't need things like mach-types, so we should #ifdef their use maybe? And if you agree, what is the best #define statement that we should use to check?
> > 4) What about REG_ACCESS_[R,W,RW,M,MASK]? Why do you need all these? And > > although I've not checked all your code with detail, I can see that you > > only use them when debugging. I'm particularly intrigued with M and > > MASK... > > > I introduced them to trap illegal register accesses like writing a > read-only register or accessing a 16bit register with a 32bit access. > Furthermore there are some registers in the chip that implement only > part of the bits from the OHCI spec. The remaining bits are stored in > a shadow copy of the register and maintained by the driver. The 'M' > bit tells the register functions that a merge of the value from the HW > register with the shadow copy is required. > Perfectly understood, except the 'MASK'. I mean it even has the same number (0x600) as 'RW'... And while RW is R+W masks together, why have the same thing with another name? Thanks, Dimitris
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