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

[Rafał Miłecki]

2011/3/18 George Kashperko <george at 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...

-- 
Rafał