cpufreq: SPEAr: Add CPUFreq driver

SPEAr is an ARM based family of SoCs. This patch adds in support of cpufreq
driver for SPEAr SoCs. It is supported via DT only and so bindings are present
in binding document.

Signed-off-by: Deepak Sikri <deepak.sikri@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-spear.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-spear.txt
new file mode 100644
index 000000000000..f3d44984d91c
--- /dev/null
+++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-spear.txt
@@ -0,0 +1,42 @@
+SPEAr cpufreq driver
+-------------------
+
+SPEAr SoC cpufreq driver for CPU frequency scaling.
+It supports both uniprocessor (UP) and symmetric multiprocessor (SMP) systems
+which share clock across all CPUs.
+
+Required properties:
+- cpufreq_tbl: Table of frequencies CPU could be transitioned into, in the
+  increasing order.
+
+Optional properties:
+- clock-latency: Specify the possible maximum transition latency for clock, in
+  unit of nanoseconds.
+
+Both required and optional properties listed above must be defined under node
+/cpus/cpu@0.
+
+Examples:
+--------
+cpus {
+
+	<...>
+
+	cpu@0 {
+		compatible = "arm,cortex-a9";
+		reg = <0>;
+
+		<...>
+
+		cpufreq_tbl = < 166000
+				200000
+				250000
+				300000
+				400000
+				500000
+				600000 >;
+	};
+
+	<...>
+
+};