dt: cpufreq: brcm: New binding document for brcmstb-avs-cpufreq

Add the binding document for the new brcmstb-avs-cpufreq driver.

Signed-off-by: Markus Mayer <mmayer@broadcom.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 78 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/cpufreq/brcm,stb-avs-cpu-freq.txt b/Documentation/devicetree/bindings/cpufreq/brcm,stb-avs-cpu-freq.txt
new file mode 100644
index 000000000000..af2385795d78
--- /dev/null
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@@ -0,0 +1,78 @@
+Broadcom AVS mail box and interrupt register bindings
+=====================================================
+
+A total of three DT nodes are required. One node (brcm,avs-cpu-data-mem)
+references the mailbox register used to communicate with the AVS CPU[1]. The
+second node (brcm,avs-cpu-l2-intr) is required to trigger an interrupt on
+the AVS CPU. The interrupt tells the AVS CPU that it needs to process a
+command sent to it by a driver. Interrupting the AVS CPU is mandatory for
+commands to be processed.
+
+The interface also requires a reference to the AVS host interrupt controller,
+so a driver can react to interrupts generated by the AVS CPU whenever a command
+has been processed. See [2] for more information on the brcm,l2-intc node.
+
+[1] The AVS CPU is an independent co-processor that runs proprietary
+firmware. On some SoCs, this firmware supports DFS and DVFS in addition to
+Adaptive Voltage Scaling.
+
+[2] Documentation/devicetree/bindings/interrupt-controller/brcm,l2-intc.txt
+
+
+Node brcm,avs-cpu-data-mem
+--------------------------
+
+Required properties:
+- compatible: must include: brcm,avs-cpu-data-mem and
+              should include: one of brcm,bcm7271-avs-cpu-data-mem or
+                              brcm,bcm7268-avs-cpu-data-mem
+- reg: Specifies base physical address and size of the registers.
+- interrupts: The interrupt that the AVS CPU will use to interrupt the host
+              when a command completed.
+- interrupt-parent: The interrupt controller the above interrupt is routed
+                    through.
+- interrupt-names: The name of the interrupt used to interrupt the host.
+
+Optional properties:
+- None
+
+Node brcm,avs-cpu-l2-intr
+-------------------------
+
+Required properties:
+- compatible: must include: brcm,avs-cpu-l2-intr and
+              should include: one of brcm,bcm7271-avs-cpu-l2-intr or
+                              brcm,bcm7268-avs-cpu-l2-intr
+- reg: Specifies base physical address and size of the registers.
+
+Optional properties:
+- None
+
+
+Example
+=======
+
+	avs_host_l2_intc: interrupt-controller@f04d1200 {
+		#interrupt-cells = <1>;
+		compatible = "brcm,l2-intc";
+		interrupt-parent = <&intc>;
+		reg = <0xf04d1200 0x48>;
+		interrupt-controller;
+		interrupts = <0x0 0x19 0x0>;
+		interrupt-names = "avs";
+	};
+
+	avs-cpu-data-mem@f04c4000 {
+		compatible = "brcm,bcm7271-avs-cpu-data-mem",
+				"brcm,avs-cpu-data-mem";
+		reg = <0xf04c4000 0x60>;
+		interrupts = <0x1a>;
+		interrupt-parent = <&avs_host_l2_intc>;
+		interrupt-names = "sw_intr";
+	};
+
+	avs-cpu-l2-intr@f04d1100 {
+		compatible = "brcm,bcm7271-avs-cpu-l2-intr",
+				"brcm,avs-cpu-l2-intr";
+		reg = <0xf04d1100 0x10>;
+	};