On Mon, Mar 04, 2019 at 10:55:36AM -0800, Patrick Venture wrote: > Document the ast2400, ast2500 PCI-to-AHB bridge control driver bindings. > > Signed-off-by: Patrick Venture <venture@xxxxxxxxxx> > --- > Changes for v6: > - None > Changes for v5: > - None > Changes for v4: > - None > Changes for v3: > - None > Changes for v2: > - Added comment about syscon required parameter. > --- > .../bindings/misc/aspeed-p2a-ctrl.txt | 32 +++++++++++++++++++ > 1 file changed, 32 insertions(+) > create mode 100644 Documentation/devicetree/bindings/misc/aspeed-p2a-ctrl.txt > > diff --git a/Documentation/devicetree/bindings/misc/aspeed-p2a-ctrl.txt b/Documentation/devicetree/bindings/misc/aspeed-p2a-ctrl.txt > new file mode 100644 > index 000000000000..1092d62d1c92 > --- /dev/null > +++ b/Documentation/devicetree/bindings/misc/aspeed-p2a-ctrl.txt > @@ -0,0 +1,32 @@ > +====================================================================== > +Device tree bindings for Aspeed AST2400/AST2500 PCI-to-AHB Bridge Control Driver > +====================================================================== > + > +The bridge is available on platforms with the VGA enabled on the Aspeed device. > +In this case, the host has access to a 64KiB window into all of the BMC's > +memory. The BMC can disable this bridge. If the bridge is enabled, the host > +has read access to all the regions of memory, however the host only has read > +and write access depending on a register controlled by the BMC. > + > +Required properties: > +=================== > + > + - compatible: must be one of: > + - "aspeed,ast2400-p2a-ctrl" > + - "aspeed,ast2500-p2a-ctrl" > + > + - syscon: handle to syscon device node controlling PCI. > + > +Optional properties: > +=================== > + > +- memory-region: A phandle to a reserved_memory region to be used for the PCI > + to AHB mapping > + > +Example: > + > +p2a: p2a-control@1e6e2000 { > + compatible = "aspeed,ast2400-p2a-ctrl"; > + memory-region = <&reserved_memory>; > + syscon = <&syscon>; Make this node a child of what you are pointing to instead if this the only control interface. Rob