[+cc devicetree list; I'm devicetree-illiterate]
On Tue, Dec 10, 2013 at 12:53 PM, Rajat Jain <[email protected]> wrote: > Hello, > > I am trying to understand and create device tree for a new powerpc platform. > (Please feel free to point out any problems with my device tree below.) My > questions: > > 1) For a PCI-PCI bridge that I'm representing like this: > > pcie@2,3 { > vendor-id = <0x10b5>; > device-id = <0x8618>; > class-code = <0x060400>; > #size-cells = <2>; > #address-cells = <3>; > device_type = "pci"; > bus-range = <0x20 0x2f>; > reg = <0x00021800 0x00000000 0x000000000 /* Cfg:2.3.0: */ > 0x00000000 0x00000000>; > ranges = <0x02000000 0x00000000 0xA0000000 /* Mem behind bridge: > 0xA0000000 - 0xA03FFFFF */ > 0x02000000 0x00000000 0xA0000000 > 0x00000000 0x04000000>; > }; > > Is the above is only to _notify_ the kernel that this is how the firmware > shall be setting the PCI bridge (Thus firmware has obligation of setting it > like this before passing control to the kernel), and hence the kernel will > merely take note of it and not really configure the bridge registers? > > Or is the above telling the kernel that this is how the kernel should _setup_ > the device (thus firmware does not set up the device, but rather the kernel > use this info to setup the device)? > > 2) For an PCI endpoint that I am representing like this: > > > xyz@20,0 { > vendor-id = ... > device-id = ... > class-code = <0x0880>; > compatible = ... > ... > reg = <0x00200000 0x00000000 0x00000000 /* Cfg:20.0.0: */ > 0x00000000 0x00000000 > 0x02200010 0x00000000 0xA0000000 /* Mem:20.0.0:(Bar0) > 64MB@0xA0000000 */ > 0x00000000 0x04000000>; > ... > }; > > Does the above tell the kernel to _program_ the BAR0 register using the above > address? Or does it cause the kernel to assume that the BAR0 has been > programmed with this address? > > 3) Lastly, what is the difference in behavior when I select PCI_PROBE_NORMAL > over PCI_PROBE_DEVTREE? > > Thanks, > > Rajat > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
