37 lines
1.8 KiB
Plaintext
37 lines
1.8 KiB
Plaintext
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ANDROID USB:
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This describes the device tree node for the Android USB gadget device.
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This works in conjunction with a USB Device Controller (UDC) to provide
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a dynamically configurable composition of functions to be exposed when
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connected to a USB host.
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Required properties:
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- compatible: should be "qcom,android-usb"
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Optional properties :
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- reg : offset and length of memory region that is used by device to
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update USB PID and serial numbers used by bootloader in DLOAD mode.
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- qcom,pm-qos-latency : This property must be a list of three integer values
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(perf, normal, sleep) where each value respresents DMA latency in microsecs.
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First value represents DMA latency to vote with pm_qos when back to back USB
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transfers are happening and it requires USB thoughput to be maximum.
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Second value represents value to vote when not many USB transfers are
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happening and it is OK to have higher DMA latency to save power.
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Third value represents DMA latency to vote when USB BUS is IDLE and absolutely
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no transfers are happening. It should allow transition to lowest power state.
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- qcom,usb-core-id: Index to refer USB hardware core to bind android gadget driver
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with UDC if multiple USB peripheral controllers are present. If unspecified,
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core is set to zero by default.
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- qcom,supported-func: Represents list of supported function drivers. If this
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property is present android USB driver dynamically creats the list of
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supported function drivers and uses this list instead of statically defined default
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supported function driver list.
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Example Android USB device node :
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android_usb@fc42b0c8 {
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compatible = "qcom,android-usb";
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reg = <0xfc42b0c8 0xc8>;
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qcom,pm-qos-latency = <2 1001 12701>;
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qcom,supported-func = "rndis_gsi","ecm_gsi","rmnet_gsi";
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qcom,usb-core-id = <1>;
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};
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