[PATCH v4 3/5] drivers: bus: Add Simple Power-Managed Bus DT Bindings

Geert Uytterhoeven
2015-01-26T16:16:15Z

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
---
v4:
- Replace "simple-bus" by "simple-pm-bus",
- Remove the "renesas,bsc" bindings. They will be specified in a
separate document.

v3:
- Add Tested-by,
- Document required properties inherited from "simple-bus",
- Document required "reg" property for "renesas,bsc",
- Move "ranges" before "reg" in the example,

v2:
- New.
---
.../devicetree/bindings/bus/simple-pm-bus.txt | 41 ++++++++++++++++++++++
1 file changed, 41 insertions(+)
create mode 100644 Documentation/devicetree/bindings/bus/simple-pm-bus.txt

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 0000000000000000..0415e93a816c5ac0
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/simple-pm-bus.txt
@@ -0,0 +1,41 @@
+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.
+
+The bindings for the Simple Power-Managed Bus extend the bindings for
+"simple-bus", as specified in ePAPR.
+
+
+Required properties:
+ - compatible: Must contain at least "simple-pm-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.
+
+
+Example:
+
+ bsc: bus at 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>;
+ };
--
1.9.1