63 lines
2.1 KiB
Plaintext
63 lines
2.1 KiB
Plaintext
MSM Bus static bandwidth rules for adhoc bus topologies
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Buses are the interconnects between various devices. The devices are
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connected in different topologies. The static bandwidth rules allow
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setting up SOC specific rules to monitor certain bandwidth requests
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at different bus nodes. When the conditions of the rule are met
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the bus driver will be given a list of actions to be take on specific
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bus master ports (throttle on/off, what bandwidth to throttle to etc).
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The mandatory properties for bus driver are:
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compatible: "qcom,msm-bus-static-bw-rules"
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The static_rules node can have numerous rules for the different bandwidth voting
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conditions to be monitored. The mandatory properties for the rules are
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- qcom,src-nodes: An array of phandles denoting the source nodes
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whose bandwidth votes need to be monitored.
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- qcom,src-field: This field represents the voted field of the
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source node to be monitored. Possible values
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are FLD_IB/FLD_AB/FLD_CLK
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- qcom,src-op: The operand to be used when evaluating a node's
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bandwidth vote with a threshold.Possible values
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are OP_LE/OP_LT/OP_GT/OP_GE.
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- qcom,thresh: The threshold in Kbytes/s to be used in vote
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evaluation.
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- qcom,mode: The QoS mode to be applied when this rule's
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criterion are satisfied. Possible values are
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THROTTLE_ON/THROTTLE_OFF
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- qcom,dest-node: An array of phandles representing the nodes to
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which the QoS mode is to be applied.
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The optional properties for the rule node are:
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- qcom,dest-bw: The destination bandwidth value in Kbytes/s to
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be used toward the QoS mode for the destination
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node.
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Example:
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static-rules {
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compatible = "qcom,msm-bus-static-bw-rules";
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#address-cells = <1>;
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#size-cells = <0>;
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rule@0 {
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qcom,src-nodes = <&mas_apss>;
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qcom,src-field = <FLD_IB>;
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qcom,src-op = <OP_LE>;
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qcom,thresh = <1599078>;
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qcom,mode = <THROTTLE_ON>;
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qcom,dest-node = <&mas_apss>;
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qcom,dest-bw = <1599078>;
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};
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rule@1 {
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qcom,src-nodes = <&mas_apss>;
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qcom,src-field = <FLD_IB>;
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qcom,src-op = <OP_GT>;
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qcom,thresh = <1599078>;
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qcom,mode = <THROTTLE_OFF>;
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qcom,dest-node = <&mas_apss>;
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};
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};
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