[U-Boot] PCI on mpc832x?

[Joakim Tjernlund]

Kumar Gala <galak at kernel.crashing.org> wrote on 27/04/2009 16:12:35:

> From:
> 
> Kumar Gala <galak at kernel.crashing.org>
> 
> To:
> 
> Joakim Tjernlund <joakim.tjernlund at transmode.se>
> 
> Cc:
> 
> Scott Wood <scottwood at freescale.com>, u-boot at lists.denx.de
> 
> Date:
> 
> 27/04/2009 16:15
> 
> Subject:
> 
> Re: [U-Boot] PCI on mpc832x?
> 
> 
> On Apr 24, 2009, at 9:11 AM, Joakim Tjernlund wrote:
> 
> > Scott Wood <scottwood at freescale.com> wrote on 23/04/2009 18:40:01:
> >>
> >> On Thu, Apr 23, 2009 at 03:32:11PM +0200, Joakim Tjernlund wrote:
> >>> Still trying to wrap my head around PCI and I wonder if I need to do
> > some
> >>> HW init in u-boot in order to use the PCI controller in Linux?
> >>
> >> Yes.  See pci_init_board() in mpc8323erdb for an example.
> >
> > Thanks Scott, this was very helpful.
> >
> > I am trying to map the "ranges" property in the OF tree and I am 
> > looking
> > at
> > the dts files in the kernel tree.
> > There are three that comes somewhat close but they all have somewhat
> > different
> > "ranges" propery:
> >
> > mpc832x_mds.dts:
> > ranges = <0x02000000 0x0 0x90000000 0x90000000 0x0 0x10000000
> 
> this is PCI MMIO non-prefetch @ 0x90000000 (cpu & pci) of size 256M
> 
> >           0x42000000 0x0 0x80000000 0x80000000 0x0 0x10000000
> 
> this is PCI MMIO prefetch @ 0x80000000 (cpu & pci) of size 256M
> 
> >           0x01000000 0x0 0x00000000 0xd0000000 0x0 0x00100000>;
> 
> this is PCI IO @ @ cpu phy 0xd0000000 pci io 0x0 of size 1M
> 
> > mpc832x_rdb.dts:
> > ranges = <0x42000000 0x0 0x80000000 0x80000000 0x0 0x10000000
> >           0x02000000 0x0 0x90000000 0x90000000 0x0 0x10000000
> >           0x01000000 0x0 0xd0000000 0xd0000000 0x0 0x04000000>;
> >
> > mpc8313erdb.dts:
> > ranges = <0x02000000 0x0 0x90000000 0x90000000 0x0 0x10000000
> >           0x42000000 0x0 0x80000000 0x80000000 0x0 0x10000000
> >           0x01000000 0x0 0x00000000 0xe2000000 0x0 0x00100000>;
> >
> > Don't understand how I should do here. Just select the mpc832x_rdb.dts
> > "ranges" and define my base addresses similarly?
> > #define CFG_PCI1_MEM_BASE       0x80000000
> > #define CFG_PCI1_MEM_PHYS       CFG_PCI1_MEM_BASE
> > #define CFG_PCI1_MEM_SIZE       0x10000000      /* 256M */
> > #define CFG_PCI1_MMIO_BASE        0x90000000
> > #define CFG_PCI1_MMIO_PHYS        CFG_PCI1_MMIO_BASE
> > #define CFG_PCI1_MMIO_SIZE        0x10000000    /* 256M */
> > #define CFG_PCI1_IO_BASE        0xd0000000
> > #define CFG_PCI1_IO_PHYS        CFG_PCI1_IO_BASE
> > #define CFG_PCI1_IO_SIZE        0x4000000       /* 64M */
> 
> this is overkill for IO, 64k is the max.  (its probably inherited when 
> we didn't know better).
> 

I think I got the mapping of memory space now, thanks.

A few questions though. I have noted that some boards map the PCI IO space
to 0x0 and some use the same address space as the CPU. If I use
the CPU address space as PCI IO space I get(in linux):
  PCI 0000:00 Cannot reserve Legacy IO [0x00-0xfff]
I don't understand what is best to do here, stay on 0x0 or move to CPU 
address space?

with  CONFIG_PCI_QUIRKS=y Linux prints:
 PCI: Bus scan for 0000:00 returning with max=00
 pci_bus 0000:00: resource 0 io:  [0x00-0xfffff]
 pci_bus 0000:00: resource 1 mem: [0x80000000-0x8fffffff]
 pci_bus 0000:00: resource 2 mem: [0x90000000-0x9fffffff]

But if I turn off CONFIG_PCI_QUIRKS I get:
 PCI: Bus scan for 0000:00 returning with max=00
 PCI: Cannot allocate resource region 0 of device 0000:00:00.0, will remap
 PCI: Cannot allocate resource region 2 of device 0000:00:00.0, will remap
 pci 0000:00:00.0: BAR 2: got res [0x80000000-0x87ffffff] bus 
[0x80000000-0x87ffffff] flags 0x2002120c
 pci 0000:00:00.0: BAR 2: moved to bus [0x80000000-0x87ffffff] flags 
0x2120c
 pci 0000:00:00.0: BAR 0: got res [0x90000000-0x901fffff] bus 
[0x90000000-0x901fffff] flags 0x20020200
 pci 0000:00:00.0: BAR 0: moved to bus [0x90000000-0x901fffff] flags 
0x20200
 pci_bus 0000:00: resource 0 io:  [0x00-0xfffff]
 pci_bus 0000:00: resource 1 mem: [0x80000000-0x8fffffff]
 pci_bus 0000:00: resource 2 mem: [0x90000000-0x9fffffff]

The BAR ... printout feels a bit off. Why do I need quirks on for
a clean boot?

 Jocke