Add device tree binding documentation for the Qualcomm GLINK RPM, used for communication with the Resource Power Management subsystem in various Qualcomm SoCs.
Signed-off-by: Bjorn Andersson <bjorn.anders...@linaro.org> --- .../devicetree/bindings/soc/qcom/qcom,glink.txt | 73 ++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 Documentation/devicetree/bindings/soc/qcom/qcom,glink.txt diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,glink.txt b/Documentation/devicetree/bindings/soc/qcom/qcom,glink.txt new file mode 100644 index 000000000000..da92c4f787f3 --- /dev/null +++ b/Documentation/devicetree/bindings/soc/qcom/qcom,glink.txt @@ -0,0 +1,73 @@ +Qualcomm RPM GLINK binding + +This binding describes the Qualcomm RPM GLINK, a fifo based mechanism for +communication with the Resource Power Management system on various Qualcomm +platforms. + +- compatible: + Usage: required + Value type: <stringlist> + Definition: must be "qcom,glink-rpm" + +- interrupts: + Usage: required + Value type: <prop-encoded-array> + Definition: should specify the IRQ used by the remote processor to + signal this processor about communication related events + +- qcom,rpm-msg-ram: + Usage: required + Value type: <prop-encoded-array> + Definition: handle to RPM message memory resource + +- qcom,ipc: + Usage: required + Value type: <prop-encoded-array> + Definition: three entries specifying the outgoing ipc bit used for + signaling the remote processor: + - phandle to a syscon node representing the apcs registers + - u32 representing offset to the register within the syscon + - u32 representing the ipc bit within the register + += GLINK DEVICES +Each subnode of the GLINK node represent function tied to a virtual +communication channel. The name of the nodes are not important. The properties +of these nodes are defined by the individual bindings for the specific function +- but must contain the following property: + +- qcom,glink-channels: + Usage: required + Value type: <stringlist> + Definition: a list of channels tied to this function, used for matching + the function to a set of virtual channels + += EXAMPLE +The following example represents the GLINK RPM node on a MSM8996 device, with +the function for the "rpm_request" channel defined, which is used for +regualtors and root clocks. + + apcs: syscon@f9011000 { + compatible = "syscon"; + reg = <0xf9011000 0x1000>; + }; + + rpm_msg_ram: memory@68000 { + compatible = "qcom,rpm-msg-ram"; + reg = <0x68000 0x6000>; + }; + + rpm-glink { + compatible = "qcom,glink-rpm"; + + interrupts = <GIC_SPI 168 IRQ_TYPE_EDGE_RISING>; + + qcom,rpm-msg-ram = <&rpm_msg_ram>; + qcom,ipc = <&apcs 0x10 0>; + + rpm-requests { + compatible = "qcom,rpm-msm8996"; + qcom,glink-channels = "rpm_requests"; + + ... + }; + }; -- 2.12.0