On 03/05/16 19:22, Rob Herring wrote: > On Fri, Apr 29, 2016 at 02:53:45PM +0100, Jon Hunter wrote: >> Add binding documentation for the Tegra ACONNECT bus that is part of the >> Audio Processing Engine (APE) on Tegra210. The ACONNECT bus is used to >> access devices within the APE subsystem. The APE is located in a >> separate power domain and so accesses made to the ACONNECT require the >> power domain to be enabled as well as some platform specific clocks. >> >> Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx> >> --- >> .../bindings/bus/nvidia,tegra210-aconnect.txt | 45 ++++++++++++++++++++++ >> 1 file changed, 45 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/bus/nvidia,tegra210-aconnect.txt >> >> diff --git a/Documentation/devicetree/bindings/bus/nvidia,tegra210-aconnect.txt b/Documentation/devicetree/bindings/bus/nvidia,tegra210-aconnect.txt >> new file mode 100644 >> index 000000000000..e5e915f8fca7 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/bus/nvidia,tegra210-aconnect.txt >> @@ -0,0 +1,45 @@ >> +NVIDIA Tegra ACONNECT Bus >> + >> +The Tegra ACONNECT bus is an AXI switch which is used to connnect various >> +components inside the Audio Processing Engine (APE). All CPU accesses to >> +the APE subsystem go through the ACONNECT via an APB to AXI wrapper. >> + >> +Required properties: >> +- compatible: Must be "nvidia,tegra210-aconnect". >> +- clocks: Must contain the entries for the APE clock (TEGRA210_CLK_APE), >> + and APE interface clock (TEGRA210_CLK_APB2APE). >> +- clock-names: Must contain the names "ape" and "apb2ape" for the corresponding >> + 'clocks' entries. >> +- power-domains: Must contain a phandle that points to the audio powergate >> + (namely 'aud') for Tegra210. >> +- #address-cells: The number of cells used to represent physical base addresses >> + in the host1x address space. Should be 2. >> +- #size-cells: The number of cells used to represent the size of an address >> + range in the host1x address space. Should be 2. > > Do you really need >4GB of child addresses? Sounds rather silly when you put it like that. No, its not needed. I will fix that. >> +- ranges: 1:1 mapping of the aconnect address space to the CPU address space. > > Why 1:1 for 256KB of address space? No good reason. I have looking at what we did for host1x and ahub which also have a ranges property and use a 1:1 mapping. For ahub this makes sense because it is more of a cross-bar/switch. The aconnect bus is also a switch and thought may be that is the easiest thing to do. What is recommended here? Cheers Jon -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
