From: Geert Uytterhoeven Date: Thu, 5 Feb 2015 10:11:26 +0000 (+0100) Subject: drivers: bus: Add Simple Power-Managed Bus DT Bindings X-Git-Tag: v4.1-rc1~49^2~7^2~2 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7e7c17f10484d3bad38ea4dddc98485a8a40e4aa;p=karo-tx-linux.git drivers: bus: Add Simple Power-Managed Bus DT Bindings Signed-off-by: Geert Uytterhoeven Tested-by: Ulrich Hecht Reviewed-by: Kevin Hilman Signed-off-by: Simon Horman --- diff --git a/Documentation/devicetree/bindings/bus/simple-pm-bus.txt b/Documentation/devicetree/bindings/bus/simple-pm-bus.txt new file mode 100644 index 000000000000..d032237512c2 --- /dev/null +++ b/Documentation/devicetree/bindings/bus/simple-pm-bus.txt @@ -0,0 +1,44 @@ +Simple Power-Managed Bus +======================== + +A Simple Power-Managed Bus is a transparent bus that doesn't need a real +driver, as it's typically initialized by the boot loader. + +However, its bus controller is part of a PM domain, or under the control of a +functional clock. Hence, the bus controller's PM domain and/or clock must be +enabled for child devices connected to the bus (either on-SoC or externally) +to function. + +While "simple-pm-bus" follows the "simple-bus" set of properties, as specified +in ePAPR, it is not an extension of "simple-bus". + + +Required properties: + - compatible: Must contain at least "simple-pm-bus". + Must not contain "simple-bus". + It's recommended to let this be preceded by one or more + vendor-specific compatible values. + - #address-cells, #size-cells, ranges: Must describe the mapping between + parent address and child address spaces. + +Optional platform-specific properties for clock or PM domain control (at least +one of them is required): + - clocks: Must contain a reference to the functional clock(s), + - power-domains: Must contain a reference to the PM domain. +Please refer to the binding documentation for the clock and/or PM domain +providers for more details. + + +Example: + + bsc: bus@fec10000 { + compatible = "renesas,bsc-sh73a0", "renesas,bsc", + "simple-pm-bus"; + #address-cells = <1>; + #size-cells = <1>; + ranges = <0 0 0x20000000>; + reg = <0xfec10000 0x400>; + interrupts = <0 39 IRQ_TYPE_LEVEL_HIGH>; + clocks = <&zb_clk>; + power-domains = <&pd_a4s>; + };