On Wed, Feb 10, 2010 at 3:20 AM, Wolfgang Grandegger <w...@grandegger.com> wrote: > Wolfgang Grandegger wrote: >> Hi David, >> >> David Miller wrote: >>> From: Anatolij Gustschin <ag...@denx.de> >>> Date: Tue, 9 Feb 2010 15:23:17 +0100 >>> >>>> In my understanding, in the ESP scsi driver the set of defines for >>>> the register offsets is common for all chip drivers. The chip driver >>>> methods for register access translate the offsets because the >>>> registers on some chips are at different intervals (4-byte, 1-byte, >>>> 16-byte for mac_esp.c). But the register order is the same for >>>> different chips. >>>> >>>> In our case non only the register order is not the same for 8xx >>>> FEC and 5121 FEC, but there are also other differences, different >>>> reserved areas between several registers, some registers are >>>> available only on 8xx and some only on 5121. >>> That only means you would need to use a table based register address >>> translation scheme, rather than a simple calculation. Something >>> like: >>> >>> static unsigned int chip_xxx_table[] = >>> { >>> [GENERIC_REG_FOO] = CHIP_XXX_FOO, >>> ... >>> }; >>> >>> static u32 chip_xxx_read_reg(struct chip *p, unsigned int reg) >>> { >>> unsigned int reg_off = chip_xxx_table[reg]; >>> >>> return readl(p->regs + reg_off); >>> } >>> >>> And this table can have special tokens in entries for >>> registers which do not exist on a chip, so you can trap >>> attempted access to them in these read/write handlers. >> >> Yes, that could be done, but to honest, I do not see any improvement in >> respect to the previous patch where the register offset were defined via >> pointers within a structure. >> >>> Please stop looking for excuses to fork this driver, a >>> unified driver I think can be done cleanly. >> >> Other people suggested to fork the driver because it's getting too ugly. > > That said, I think there is consensus that it does not make sense, and > it's even not possible, to provide a kernel image which runs on both, > the 8xx and the mpc512x. Therefore, there is also no need for sharing > this driver at run time. Compile time selection would allow a more > elegant and transparent implementation. Would that be an acceptable > solution?
I'm okay with compile time selection. g. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev