[PATCH 05/17] pci: host: pcie-dra7xx: add support for pcie-dra7xx controller

Jingoo Han
2014-05-08T08:56:38Z

On Wednesday, May 07, 2014 6:26 PM, Arnd Bergmann wrote:
> On Wednesday 07 May 2014 14:52:47 Kishon Vijay Abraham I wrote:
> > On Tuesday 06 May 2014 10:05 PM, Jason Gunthorpe wrote:
> > > On Tue, May 06, 2014 at 07:03:51PM +0530, Kishon Vijay Abraham I wrote:
> > >> +Example:
> > >> +pcie at 51000000 {
> > >> + compatible = "ti,dra7xx-pcie";
> > >> + reg = <0x51002000 0x14c>, <0x51000000 0x2000>;
> > >> + reg-names = "ti_conf", "rc_dbics";
> > >> + interrupts = <0 232 0x4>, <0 233 0x4>;
> > >> + #address-cells = >;
> > >> + #size-cells = <2>;
> > >> + device_type = "pci";
> > >> + ti,device_type = >;
> > >> + ranges = <0x00000800 0 0x20001000 0x20001000 0 0x00002000 /* Configuration Space */
> > >
> > > Configuration space should not show up in the ranges, please don't
> > > copy that mistake from other drivers, put it in reg.
> >
> > But then it needs pcie-designware.c to be modified and it will be breaking
> > other platforms no?
>
> I think the pcie-designware driver should be changed to allow either way.
> Ideally we would deprecate the existing method in a way that for new front-ends
> it doesn't work, but the old front-ends can still deal with it but also work
> if you put it into the reg property.

(+cc Pratyush Anand, Thierry Reding)

Hi Arnd,

Thank you for your comment.
Do you mean the case of Tegra PCIe as below?

./arch/arm/boot/dts/tegra20.dts
pcie-controller at 80003000 {
...
reg = <0x80003000 0x00000800 /* PADS registers */
0x80003800 0x00000200 /* AFI registers */
0x90000000 0x10000000>; /* configuration space */
...
ranges = <0x82000000 0 0x80000000 0x80000000 0 0x00001000 /* port 0 registers */
0x82000000 0 0x80001000 0x80001000 0 0x00001000 /* port 1 registers */
0x81000000 0 0 0x82000000 0 0x00010000 /* downstream I/O */
0x82000000 0 0xa0000000 0xa0000000 0 0x08000000 /* non-prefetchable memory */
0xc2000000 0 0xa8000000 0xa8000000 0 0x18000000>; /* prefetchable memory */
...

./drivers/pci/host/pci-tegra.c
/* request configuration space, but remap later, on demand */
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cs");
...
pcie->cs = devm_request_mem_region(pcie->dev, res->start,
resource_size(res), res->name);

Best regards,
Jingoo Han