Benjamin Herrenschmidt wrote: > On Thu, 2009-11-26 at 16:09 +0100, Albert Herranz wrote: > >>> Are the above OHCI and EHCI "special" ? If not, there's an existing >>> binding for that sort of thing, which btw requires properties to >>> indicate the endianness of the registers and in-memory data structures >>> etc... >>> >> They are a bit special because registers are in reverse little endian format, >> must be written in 32-bit chunks, and (all things point to) they have >> hardware bugs. > > Well.. first what is "reverse little endian" ? :-) Big endian ? >
It's the same case as the register access for the Freescale eSDHC controller, which is already in the existing sdhci-of driver. > The OHCI driver today has separate flags to control register endianness > and memory based data structures endianness. > > I think we also only use 32-bit reads and writes no ? So that should be > covered :-) > There are 8, 16 and 32 bit accesses. We need the same workarounds as present for the Freescale eSDHC controller. > As for HW bugs, well, as long as we know them we can define a quirk bit > and add the necessary workarounds to the driver :-) > Yes, that's how it was done. Although it it currently not integrated into sdhci-of. I think that the specific eSDHC code should be moved to another file, and leave the sdhci-of with the generic code and the sdhci_of_match table. Then adding a similar driver would simply consist in adding another file with the sdhci_data (containing ops and quirks) and adding an entry to the sdhci_of_match table in sdhci-of. > Do you have a patch somewhere that adds the OCHI and EHCI support btw ? > Yes, too. Although it needs review and cleanup too. I have a git tree with all the stuff, but it contains only the existing code previous to the effort of mainlining it: http://git.infradead.org/users/herraa1/gc-linux-2.6.git/shortlog/refs/heads/mini/gc-linux-2.6.31 > Cheers, > Ben. > Thanks, Albert _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
