Re: [RFC][PATCH] ssb: separate common scanning functions

[George Kashperko <george@znau.edu.ua>]

> 2011/3/18 George Kashperko <george@znau.edu.ua>:
> > Well, here you are:
> > 1. PCI hosts with PCI buscores prior rev. 13 (8Kb window)
> > offset  size    type    description
> > 0x0000  0x1000  sliding controlled with BAR0_WIN1 register
> > 0x1000  0x0800  fixed   SPROM
> > 0x1800  0x0400  fixed   PCI core (core registers 0x0000 to 0x03FF range)
> > 0x1C00  0x0400  fixed   PCI core (agent registers, 0x0C00 to 0x0FFF range)
> >
> > 2. PCI hosts with PCI buscores rev. 13 and above and PCIE with
> > Chipcommon rev. up to 31 (16Kb window)
> > offset  size    type    description
> > 0x0000  0x1000  sliding controlled with BAR0_WIN1 register
> > 0x1000  0x1000  fixed   SPROM
> > 0x2000  0x1000  fixed   PCI core
> > 0x3000  0x1000  fixed   Chipcommon core
> >
> > 3. PCIE hosts with Chipcommon rev. 32 and above
> > offset  size    type    description
> > 0x0000  0x1000  sliding controlled with BAR0_WIN1 register
> > 0x1000  0x1000  sliding controlled with BAR0_WIN2 register
> > 0x2000  0x1000  fixed   PCI core
> > 0x3000  0x1000  fixed   Chipcommon core
> >
> > As you can see even if PCI_REVISION can't feed us with guaranteed choice
> > of either of these 3 layouts we can distingiush between them easily like
> > following:
> >
> > if (pci_is_pcie(dev)) {
> >        u32 chipid = ioread32(bar0_base + 0x3000);
> >        if (chipid & 0x10000000)
> >                /* AXI, Chipcommon rev. is 32+ */
> >                goto win_3_setup;
> >        else
> >                /* SB, Chipcommon rev. is <= 31 */
> >                goto win_2_setup;
> > } else {
> >        u32 idhi = ioread32(bar0_base + 0x1C00 + 0x03FC);
> >        if (((idhi & 0x00008FF0) >> 4) == 0x804)
> >                /* PCI core id */
> >                goto win_1_setup;
> >        else
> >                /* Some crap from SPROM area */
> >                goto win_2_setup;
> > }
> >
> > Therefore we can setup PCI(e) host windows for backplane access prior to
> > scanning.
> >
> > As for BAR0_WIN[12] registers, they point to physical base address on
> > backplane that will be mapped into corresponding 0x1000-size window. And
> > here again registers don't care what exactly you want to see there. Both
> > the windows can be controlled independently.
> >
> > Finally, you might noticed we don't have SPROM in last 3rd layout. Thats
> > because it is in Chipcommon registers' space. For layouts #1 & #2 BAR0
> > range 0x1000 to 0x2000 is either mapped to actual SPROM or to SPROM
> > shadow in PCI core.
> 
> Wohoo, and this is second part of info I really needed, thanks a lot!
> I think there are mistakes in it, but I just wanted to get the idea of
> windows. So thanks a lot.
> 
> As for mistakes:
> 1) The split is not 1-31 vs. 32-... I believe it is 1-30 vs. 31-...
> 2) On chipco >= 31 SSB SPROM seems to be 0x800
> Maybe sth more...
> 
Watch bcmsrom.c for #define SROM_OFFSET

For Chipcommons rev. >31 (the same as >=32) SPROM is in Chipcommon at
0x0800 offset - 0x3800 offset of BAR0 (if CAP_SPROM capability bit is
set), otherwise SPROM is unavailable.
For Chipcommons rev. <=31 (the same as <32) SPROM is mapped to 0x1000
offset of BAR0.

Have nice day,
George