Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / Documentation / devicetree / bindings / clock / pistachio-clock.txt

diff --git a/kernel/Documentation/devicetree/bindings/clock/pistachio-clock.txt b/kernel/Documentation/devicetree/bindings/clock/pistachio-clock.txt
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+Imagination Technologies Pistachio SoC clock controllers
+========================================================
+
+Pistachio has four clock controllers (core clock, peripheral clock, peripheral
+general control, and top general control) which are instantiated individually
+from the device-tree.
+
+External clocks:
+----------------
+
+There are three external inputs to the clock controllers which should be
+defined with the following clock-output-names:
+- "xtal": External 52Mhz oscillator (required)
+- "audio_clk_in": Alternate audio reference clock (optional)
+- "enet_clk_in": Alternate ethernet PHY clock (optional)
+
+Core clock controller:
+----------------------
+
+The core clock controller generates clocks for the CPU, RPU (WiFi + BT
+co-processor), audio, and several peripherals.
+
+Required properties:
+- compatible: Must be "img,pistachio-clk".
+- reg: Must contain the base address and length of the core clock controller.
+- #clock-cells: Must be 1.  The single cell is the clock identifier.
+  See dt-bindings/clock/pistachio-clk.h for the list of valid identifiers.
+- clocks: Must contain an entry for each clock in clock-names.
+- clock-names: Must include "xtal" (see "External clocks") and
+  "audio_clk_in_gate", "enet_clk_in_gate" which are generated by the
+  top-level general control.
+
+Example:
+       clk_core: clock-controller@18144000 {
+               compatible = "img,pistachio-clk";
+               reg = <0x18144000 0x800>;
+               clocks = <&xtal>, <&cr_top EXT_CLK_AUDIO_IN>,
+                        <&cr_top EXT_CLK_ENET_IN>;
+               clock-names = "xtal", "audio_clk_in_gate", "enet_clk_in_gate";
+
+               #clock-cells = <1>;
+       };
+
+Peripheral clock controller:
+----------------------------
+
+The peripheral clock controller generates clocks for the DDR, ROM, and other
+peripherals.  The peripheral system clock ("periph_sys") generated by the core
+clock controller is the input clock to the peripheral clock controller.
+
+Required properties:
+- compatible: Must be "img,pistachio-periph-clk".
+- reg: Must contain the base address and length of the peripheral clock
+  controller.
+- #clock-cells: Must be 1.  The single cell is the clock identifier.
+  See dt-bindings/clock/pistachio-clk.h for the list of valid identifiers.
+- clocks: Must contain an entry for each clock in clock-names.
+- clock-names: Must include "periph_sys", the peripheral system clock generated
+  by the core clock controller.
+
+Example:
+       clk_periph: clock-controller@18144800 {
+               compatible = "img,pistachio-clk-periph";
+               reg = <0x18144800 0x800>;
+               clocks = <&clk_core CLK_PERIPH_SYS>;
+               clock-names = "periph_sys";
+
+               #clock-cells = <1>;
+       };
+
+Peripheral general control:
+---------------------------
+
+The peripheral general control block generates system interface clocks and
+resets for various peripherals.  It also contains miscellaneous peripheral
+control registers.  The system clock ("sys") generated by the peripheral clock
+controller is the input clock to the system clock controller.
+
+Required properties:
+- compatible: Must include "img,pistachio-periph-cr" and "syscon".
+- reg: Must contain the base address and length of the peripheral general
+  control registers.
+- #clock-cells: Must be 1.  The single cell is the clock identifier.
+  See dt-bindings/clock/pistachio-clk.h for the list of valid identifiers.
+- clocks: Must contain an entry for each clock in clock-names.
+- clock-names: Must include "sys", the system clock generated by the peripheral
+  clock controller.
+
+Example:
+       cr_periph: syscon@18144800 {
+               compatible = "img,pistachio-cr-periph", "syscon";
+               reg = <0x18148000 0x1000>;
+               clocks = <&clock_periph PERIPH_CLK_PERIPH_SYS>;
+               clock-names = "sys";
+
+               #clock-cells = <1>;
+       };
+
+Top-level general control:
+--------------------------
+
+The top-level general control block contains miscellaneous control registers and
+gates for the external clocks "audio_clk_in" and "enet_clk_in".
+
+Required properties:
+- compatible: Must include "img,pistachio-cr-top" and "syscon".
+- reg: Must contain the base address and length of the top-level
+  control registers.
+- clocks: Must contain an entry for each clock in clock-names.
+- clock-names: Two optional clocks, "audio_clk_in" and "enet_clk_in" (see
+  "External clocks").
+- #clock-cells: Must be 1.  The single cell is the clock identifier.
+  See dt-bindings/clock/pistachio-clk.h for the list of valid identifiers.
+
+Example:
+       cr_top: syscon@18144800 {
+               compatible = "img,pistachio-cr-top", "syscon";
+               reg = <0x18149000 0x200>;
+               clocks = <&audio_refclk>, <&ext_enet_in>;
+               clock-names = "audio_clk_in", "enet_clk_in";
+
+               #clock-cells = <1>;
+       };