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author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-12-15 14:52:16 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-12-15 14:52:16 -0300 |
commit | 8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be (patch) | |
tree | e9891aa6c295060d065adffd610c4f49ecf884f3 /Documentation/devicetree/bindings/soc/qcom/qcom,smd.txt | |
parent | a71852147516bc1cb5b0b3cbd13639bfd4022dc8 (diff) |
Linux-libre 4.3.2-gnu
Diffstat (limited to 'Documentation/devicetree/bindings/soc/qcom/qcom,smd.txt')
-rw-r--r-- | Documentation/devicetree/bindings/soc/qcom/qcom,smd.txt | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,smd.txt b/Documentation/devicetree/bindings/soc/qcom/qcom,smd.txt new file mode 100644 index 000000000..97d9b3e1b --- /dev/null +++ b/Documentation/devicetree/bindings/soc/qcom/qcom,smd.txt @@ -0,0 +1,85 @@ +Qualcomm Shared Memory Driver (SMD) binding + +This binding describes the Qualcomm Shared Memory Driver, a fifo based +communication channel for sending data between the various subsystems in +Qualcomm platforms. + +- compatible: + Usage: required + Value type: <stringlist> + Definition: must be "qcom,smd" + += EDGES + +Each subnode of the SMD node represents a remote subsystem or a remote +processor of some sort - or in SMD language an "edge". The name of the edges +are not important. +The edge is described by the following properties: + +- 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 updates + +- 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 + +- qcom,smd-edge: + Usage: required + Value type: <u32> + Definition: the identifier of the remote processor in the smd channel + allocation table + +- qcom,remote-pid: + Usage: optional + Value type: <u32> + Definition: the identifier for the remote processor as known by the rest + of the system. + += SMD DEVICES + +In turn, subnodes of the "edges" represent devices tied to SMD channels on that +"edge". The names of the devices are not important. The properties of these +nodes are defined by the individual bindings for the SMD devices - but must +contain the following property: + +- qcom,smd-channels: + Usage: required + Value type: <stringlist> + Definition: a list of channels tied to this device, used for matching + the device to channels + += EXAMPLE + +The following example represents a smd node, with one edge representing the +"rpm" subsystem. For the "rpm" subsystem we have a device tied to the +"rpm_request" channel. + + apcs: syscon@f9011000 { + compatible = "syscon"; + reg = <0xf9011000 0x1000>; + }; + + smd { + compatible = "qcom,smd"; + + rpm { + interrupts = <0 168 1>; + qcom,ipc = <&apcs 8 0>; + qcom,smd-edge = <15>; + + rpm_requests { + compatible = "qcom,rpm-msm8974"; + qcom,smd-channels = "rpm_requests"; + + ... + }; + }; + }; |