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

[Jingoo Han <jg1.han@samsung.com>]

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@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@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