[PATCH v10 5/6] dt-bindings: mailbox: qcom: Document the APCS clock binding

[Georgi Djakov]

Update the binding documentation for APCS to mention that the APCS
hardware block also expose a clock controller functionality.

The APCS clock controller is a mux and half-integer divider. It has the
main CPU PLL as an input and provides the clock for the application CPU.

Signed-off-by: Georgi Djakov <georgi.dja...@linaro.org>
---
 .../bindings/mailbox/qcom,apcs-kpss-global.txt         | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git 
a/Documentation/devicetree/bindings/mailbox/qcom,apcs-kpss-global.txt 
b/Documentation/devicetree/bindings/mailbox/qcom,apcs-kpss-global.txt
index fb961c310f44..16964f0c1773 100644
--- a/Documentation/devicetree/bindings/mailbox/qcom,apcs-kpss-global.txt
+++ b/Documentation/devicetree/bindings/mailbox/qcom,apcs-kpss-global.txt
@@ -15,12 +15,21 @@ platforms.
        Usage: required
        Value type: <prop-encoded-array>
        Definition: must specify the base address and size of the global block
+- clocks:
+       Usage: required if #clocks-cells property is present
+       Value type: <phandle>
+       Definition: phandle to the input PLL, which feeds the APCS mux/divider
 
 - #mbox-cells:
        Usage: required
        Value type: <u32>
        Definition: as described in mailbox.txt, must be 1
 
+- #clock-cells:
+       Usage: optional
+       Value type: <u32>
+       Definition: as described in clock.txt, must be 0
+
 
 = EXAMPLE
 The following example describes the APCS HMSS found in MSM8996 and part of the
@@ -44,3 +53,12 @@ GLINK RPM referencing the "rpm_hlos" doorbell therein.
                mbox-names = "rpm_hlos";
        };
 
+Below is another example of the APCS binding on MSM8916 platforms:
+
+       apcs: mailbox@b011000 {
+               compatible = "qcom,msm8916-apcs-kpss-global";
+               reg = <0xb011000 0x1000>;
+               #mbox-cells = <1>;
+               clocks = <&a53pll>;
+               #clock-cells = <0>;
+       };