clk: qcom: Add support for SMD-RPM Clocks

This adds initial support for clocks controlled by the Resource
Power Manager (RPM) processor on some Qualcomm SoCs, which use
the qcom_smd_rpm driver to communicate with RPM.
Such platforms are msm8916, apq8084 and msm8974.

The RPM is a dedicated hardware engine for managing the shared
SoC resources in order to keep the lowest power profile. It
communicates with other hardware subsystems via shared memory
and accepts clock requests, aggregates the requests and turns
the clocks on/off or scales them on demand.

This driver is based on the codeaurora.org driver:
https://www.codeaurora.org/cgit/quic/la/kernel/msm-3.10/tree/drivers/clk/qcom/clock-rpm.c

Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
[sboyd@codeaurora.org: Remove useless braces for single line if]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

1 files changed, 36 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/clock/qcom,rpmcc.txt b/Documentation/devicetree/bindings/clock/qcom,rpmcc.txt
new file mode 100644
index 000000000000..e3e13226d798
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/qcom,rpmcc.txt
@@ -0,0 +1,36 @@
+Qualcomm RPM Clock Controller Binding
+------------------------------------------------
+The RPM is a dedicated hardware engine for managing the shared
+SoC resources in order to keep the lowest power profile. It
+communicates with other hardware subsystems via shared memory
+and accepts clock requests, aggregates the requests and turns
+the clocks on/off or scales them on demand.
+
+Required properties :
+- compatible : shall contain only one of the following. The generic
+               compatible "qcom,rpmcc" should be also included.
+
+			"qcom,rpmcc-msm8916", "qcom,rpmcc"
+
+- #clock-cells : shall contain 1
+
+Example:
+	smd {
+		compatible = "qcom,smd";
+
+		rpm {
+			interrupts = <0 168 1>;
+			qcom,ipc = <&apcs 8 0>;
+			qcom,smd-edge = <15>;
+
+			rpm_requests {
+				compatible = "qcom,rpm-msm8916";
+				qcom,smd-channels = "rpm_requests";
+
+				rpmcc: clock-controller {
+					compatible = "qcom,rpmcc-msm8916", "qcom,rpmcc";
+					#clock-cells = <1>;
+				};
+			};
+		};
+	};