Subject: Re: pci and pcie device-tree binding - range No cells

From: Rob Herring <[email-masked]>
Date: Mon, 10 Dec 2012 08:26:37 -0600

On 12/10/2012 06:20 AM, Michal Simek wrote:
> Hi Grant and others,
> 
> I have a question regarding number of cells in ranges property
> for pci and pcie nodes.
> 
> Linux pci/pcie powerpc DTSes contain 7 cells (xpedite5370.dts,
> sequoia.dts, etc)
> but also 6 cells format too (mpc832x_mds.dts)
> 
> Here is shown 6 cells ranges format and describe
> http://devicetree.org/Device_Tree_Usage#PCI_Host_Bridge
> 
> And also in documentation in the linux
> Documentation/devicetree/bindings/pci/83xx-512x-pci.txt
> 
> Both format uses:
> #size-cells = <2>;
> #address-cells = <3>;
> 
> What is valid format?

Both. 7 cells are valid when the host (parent) bus is 64-bit and 6 cells
are valid when the host bus is 32-bit. The ranges property is <<child
address> <parent address> <size>>. The parent address #address-cells is
taken from the parent node.

Rob