[PATCH 5/7] Documentation: bindings: Add SMP related documentation

[Carlo Caione <carlo@caione.org>]

From: Carlo Caione <carlo@endlessm.com>

With this patch we add documentation for:

* power-management-unit: the PMU is used to bring up the cores during
  SMP operations
* sram: among other things the sram is used to store the first code
  executed by the core when it is powered up
* cpu-enable-method: the CPU enable method used by Amlogic Meson8b SoCs

Signed-off-by: Carlo Caione <carlo@endlessm.com>
---
 .../devicetree/bindings/arm/amlogic/pmu.txt        | 16 +++++++
 .../devicetree/bindings/arm/amlogic/smp-sram.txt   | 32 +++++++++++++
 .../arm/cpu-enable-method/amlogic,meson8b-smp      | 53 ++++++++++++++++++++++
 3 files changed, 101 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/amlogic/pmu.txt
 create mode 100644 Documentation/devicetree/bindings/arm/amlogic/smp-sram.txt
 create mode 100644 Documentation/devicetree/bindings/arm/cpu-enable-method/amlogic,meson8b-smp

diff --git a/Documentation/devicetree/bindings/arm/amlogic/pmu.txt b/Documentation/devicetree/bindings/arm/amlogic/pmu.txt
new file mode 100644
index 0000000..7b9b2da
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/amlogic/pmu.txt
@@ -0,0 +1,16 @@
+Amlogic power-management-unit:
+-------------------------------
+
+The pmu is used to turn off and on different power domains of the SoCs
+This includes the power to the CPU cores.
+
+Required node properties:
+- compatible value : = "amlogic,meson8b-pmu";
+- reg : physical base address and the size of the registers window
+
+Example:
+
+	pmu@c81000e4 {
+		compatible = "amlogic,meson8b-pmu", "syscon";
+		reg = <0xc81000e0 0x18>;
+	};
diff --git a/Documentation/devicetree/bindings/arm/amlogic/smp-sram.txt b/Documentation/devicetree/bindings/arm/amlogic/smp-sram.txt
new file mode 100644
index 0000000..455ca20
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/amlogic/smp-sram.txt
@@ -0,0 +1,32 @@
+Amlogic SRAM for smp bringup:
+------------------------------
+
+Amlogic's smp-capable SoCs use part of the sram for the bringup of the cores.
+Once the core gets powered up it executes the code that is residing at a
+specific location.
+
+Therefore a reserved section sub-node has to be added to the mmio-sram
+declaration.
+
+Required sub-node properties:
+- compatible : should be "amlogic,meson8b-smp-sram"
+
+The rest of the properties should follow the generic mmio-sram discription
+found in ../../misc/sram.txt
+
+Example:
+
+	sram: sram@d9000000 {
+		compatible = "mmio-sram";
+		reg = <0xd9000000 0x20000>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges = <0 0xd9000000 0x20000>;
+
+		smp-sram@1ff80 {
+			compatible = "amlogic,meson8b-smp-sram";
+			reg = <0x1ff80 0x8>;
+		};
+	};
+
+
diff --git a/Documentation/devicetree/bindings/arm/cpu-enable-method/amlogic,meson8b-smp b/Documentation/devicetree/bindings/arm/cpu-enable-method/amlogic,meson8b-smp
new file mode 100644
index 0000000..95ee458b
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/cpu-enable-method/amlogic,meson8b-smp
@@ -0,0 +1,53 @@
+=========================================================
+Secondary CPU enable-method "amlogic,meson8b-smp" binding
+=========================================================
+
+This document describes the "amlogic,meson8b-smp" method for enabling secondary
+CPUs. To apply to all CPUs, a single "amlogic,meson8b-smp" enable method should
+be defined in the "cpus" node.
+
+Enable method name:	"amlogic,meson8b-smp"
+Compatible machines:	"amlogic,meson8b"
+Compatible CPUs:	"arm,cortex-a5"
+Related properties:	(none)
+
+Example:
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		enable-method = "amlogic,meson8b-smp";
+
+		cpu@200 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a5";
+			next-level-cache = <&L2>;
+			reg = <0x200>;
+			resets = <&clkc RST_CORE0>;
+		};
+
+		cpu@201 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a5";
+			next-level-cache = <&L2>;
+			reg = <0x201>;
+			resets = <&clkc RST_CORE1>;
+		};
+
+		cpu@202 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a5";
+			next-level-cache = <&L2>;
+			reg = <0x202>;
+			resets = <&clkc RST_CORE2>;
+		};
+
+		cpu@203 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a5";
+			next-level-cache = <&L2>;
+			reg = <0x203>;
+			resets = <&clkc RST_CORE3>;
+		};
+	};
+
-- 
2.5.0