On Sun, Oct 09, 2016 at 03:49:10PM +0800, Shawn Guo wrote: > On Mon, Oct 03, 2016 at 12:44:29PM -0500, Rob Herring wrote: > > > +Example: > > > + > > > +vou: vou at 1440000 { > > > + compatible = "zte,zx296718-vou"; > > > + #address-cells = <1>; > > > + #size-cells = <1>; > > > + reg = <0x1440000 0x10000>; > > > + ranges; > > > > You still have overlapping addresses. Explicitly list the sub ranges in > > reg here used by the VOU driver if the driver usage doesn't overlap. If > > there is overlap (2 drivers accessing the same range), then you need > > some APIs between the components (or possibly regmap). > > The driver matching "zte,zx296718-vou" doesn't map or access the any > 'reg' address. The 'reg' property here is more like a hint telling > that the VOU block covers the address space of all child devices. > > I will simply drop the 'reg' property here. > > > Also, don't do an empty ranges here. Fill it in so the child nodes are > > just offsets of 0x1440000 > > Okay. I thought that empty 'ranges' is fine as long as parent and child > address spaces are identical (1:1 mapping).
It is fine, but it's just better policy to limit the scope of things. > So with your suggestion, I made the changes below. Let me know if this > is still not what you are asking for. Looks fine. With that, Acked-by: Rob Herring <robh at kernel.org> > > Shawn > > -----8<----------------- > > diff --git a/Documentation/devicetree/bindings/display/zte,vou.txt > b/Documentation/devicetree/bindings/display/zte,vou.txt > index d03ba4c4810c..6bb4ab2517ef 100644 > --- a/Documentation/devicetree/bindings/display/zte,vou.txt > +++ b/Documentation/devicetree/bindings/display/zte,vou.txt > @@ -56,14 +56,13 @@ vou: vou at 1440000 { > compatible = "zte,zx296718-vou"; > #address-cells = <1>; > #size-cells = <1>; > - reg = <0x1440000 0x10000>; > - ranges; > + ranges = <0 0x1440000 0x10000>; > > - dpc: dpc at 1440000 { > + dpc: dpc at 0 { > compatible = "zte,zx296718-dpc"; > - reg = <0x1440000 0x1000>, <0x1441000 0x1000>, > - <0x1445000 0x1000>, <0x1446000 0x1000>, > - <0x144a000 0x1000>; > + reg = <0x0000 0x1000>, <0x1000 0x1000>, > + <0x5000 0x1000>, <0x6000 0x1000>, > + <0xa000 0x1000>; > reg-names = "osd", "timing_ctrl", > "dtrc", "vou_ctrl", > "otfppu"; > @@ -74,9 +73,9 @@ vou: vou at 1440000 { > "main_wclk", "aux_wclk"; > }; > > - hdmi: hdmi at 144c000 { > + hdmi: hdmi at c000 { > compatible = "zte,zx296718-hdmi"; > - reg = <0x144c000 0x4000>; > + reg = <0xc000 0x4000>; > interrupts = <GIC_SPI 82 IRQ_TYPE_EDGE_RISING>; >