Host-detecting USB hub
An apparatus includes a processor and a machine-readable medium coupled to the processor and comprising instructions. The instructions, when loaded into the processor and executed, configure the processor to identify that a USB element has attached to a USB hub at a port, classify the USB element according to power operations of the USB element, and assign an upstream or downstream setting of the port based upon the classification of the USB element based on power operations of the USB element.
1. An apparatus, comprising:
a processor;
a non-transitory machine-readable medium coupled to the processor and comprising instructions, the instructions, when loaded into the processor and executed, configure the processor to:
identify that a USB element has attached to a USB hub at a port;
determine power operations of the USB element;
classify the USB element according to power operations of the USB element;
determine whether to operate the port in either upstream operation or downstream operation based on the determination of the power operations of the USB element;
assign a setting defining whether the port uses either upstream or downstream operation based upon the classification of the USB element based on the determination of power operations of the USB element;
classify the USB element as only a producer of power;
based on the classification of the USB element as only a producer of power, evaluate whether an enumeration process is initiated within a timeout period; and
based on a determination that the enumeration process is initiated within the timeout period, set the port as an upstream port.
2. The apparatus of claim 1 , further comprising instructions for configuring the processor to:
identify that another USB element has attached to the USB hub at another port;
determine power operations of the other USB element;
classify the other USB element as only a consumer of power; and
based on the classification of the other USB element as only a consumer of power, set the other port as a downstream port.
3. The apparatus of claim 1 , further comprising instructions for configuring the processor to:
identify that another USB element has attached to the USB hub at another port;
determine power operations of the other USB element;
classify the other USB element as only a consumer of power; and
based on the classification of the other USB element as only a consumer of power, designate the other USB element as a USB device with respect to the hub.
4. The apparatus of claim 1 , further comprising instructions for configuring the processor to:
identify that another USB element has attached to the USB hub at another port;
determine power operations of the other USB element;
classify the other USB element as only a consumer of power; and
based on the classification of the other USB element as only a consumer of power, set the other port as a downstream port until the other USB element detaches.
5. The apparatus of claim 1 , further comprising instructions for configuring the processor to:
based on the classification of the USB element as only a producer of power, set a timeout period to evaluate whether to handle the USB element as a USB host or a USB device.
6. The apparatus of claim 1 , further comprising instructions for configuring the processor to:
based on the classification of the USB element as only a producer of power, evaluate whether an enumeration process is initiated to determine whether to handle the USB element as a USB host or a USB device.
7. The apparatus of claim 1 , further comprising instructions for configuring the processor to:
based on the classification of the USB element as only a producer of power, evaluate whether the enumeration process is initiated to determine whether to set the port as a downstream port or an upstream port.
8. An apparatus, comprising:
a processor;
a non-transitory machine-readable medium coupled to the processor and comprising instructions, the instructions, when loaded into the processor and executed, configure the processor to:
identify that a USB element has attached to a USB hub at a port;
determine power operations of the USB element;
classify the USB element according to power operations of the USB element;
determine whether to operate the port in either upstream operation or downstream operation based on the determination of the power operations of the USB element;
assign a setting defining whether the port uses either upstream or downstream operation based upon the classification of the USB element based on the determination of power operations of the USB element;
classify the USB element as only a producer of power;
based on the classification of the USB element as only a producer of power, evaluate whether an enumeration process is initiated within a timeout period; and
based on a determination that the enumeration process is not initiated within the timeout period, setting the port as a downstream port.
9. The apparatus of claim 1 , further comprising instructions for configuring the processor to:
based on a determination that the enumeration process is initiated within the timeout period, assign the USB element as a USB host.
10. The apparatus of claim 8 , further comprising instructions for configuring the processor to:
the USB element as only a producer of power;
based on the classification of the USB element as only a producer of power, evaluate whether an enumeration process is initiated within a timeout period; and
based on a determination that the enumeration process is not initiated within the timeout period, assign the USB element as a USB device.
11. The apparatus of claim 1 , further comprising instructions for configuring the processor to:
classify the USB element as only a producer of power;
based on the classification of the USB element as only a producer of power, evaluate whether an enumeration process is initiated within a timeout period; and
based on a determination that the enumeration process is not initiated within the timeout period, handle the attachment as a power adapter.
12. The apparatus of claim 1 , further comprising instructions for configuring the processor to:
identify that another USB element has attached to the USB hub at another port;
determine power operations of the other USB element;
classify the other USB element as capable of both producing and receiving power;
based on the classification of the other USB element as capable of both producing and receiving power, treat the other USB element as a laptop.
13. The apparatus of claim 1 , further comprising instructions for configuring the processor to:
identify that another USB element has attached to the USB hub at another port;
determine power operations of the other USB element;
classify the other USB element as capable of both producing and receiving power;
based on the classification of the other USB element as capable of both producing and receiving power, negotiate with the other USB element to provide power from the hub while allowing the other USB element to request USB host properties.
14. A USB hub, comprising:
a processor;
a USB port;
a non-transitory machine-readable medium coupled to the processor and comprising instructions, the instructions, when loaded into the processor and executed, configure the processor to:
identify that a USB element has attached to the USB hub at the USB port;
determine power operations of the USB element;
classify the USB element according to power operations of the USB element;
determine whether to operate the port in either upstream operation or downstream operation based on the determination of the power operations of the USB element;
assign a setting defining whether the port uses either upstream or downstream operation an upstream or downstream setting of the port based upon the classification of the USB element based on the determination of power operations of the USB element;
classify the USB element as only a producer of power;
based on the classification of the USB element as only a producer of power, evaluate whether an enumeration process is initiated within a timeout period; and
based on a determination that the enumeration process is initiated within the timeout period, set the port as an upstream port.
15. A method of operating a universal serial bus (USB) hub, comprising:
identifying that a USB element has attached to the hub at a port;
determining power operations of the USB element;
classifying the USB element according to power operations of the USB element;
determining whether to operate the port in either upstream operation or downstream operation based on the determination of the power operations of the USB element; and
assigning a setting defining whether the port uses either upstream or downstream operation based upon the classification of the USB element based on the determination of power operations of the USB element;
classifying the USB element as only a producer of power; and
based on the classification of the USB element as only a producer of power, setting a timeout period;
evaluating whether an enumeration process is initiated during the timeout period to determine whether to handle the USB element as a USB host or a USB device or to set the port as a downstream port or an upstream port.
16. The method of claim 15 , further comprising:
classifying another USB element connected to another port of the hub as only a consumer of power;
based on the classification of the other USB element as only a consumer of power, setting the other port as a downstream port until the other USB element detaches; and
based on the classification of the other USB element as only a consumer of power, designating the other USB element as a USB device with respect to the hub until the other USB element detaches.
17. The method of claim 15 , further comprising:
based on a determination that the enumeration process is not initiated within the timeout period, handling the attachment as a power adapter.
18. The method of claim 15 , further comprising:
classifying another USB element connected to the hub as capable of both producing and receiving power;
based on the classification of the other USB element as capable of both producing and receiving power, negotiating with the other USB element to provide power from the hub while allowing the other USB element to request USB host properties.
19. A USB hub, comprising:
a processor;
a USB port;
a non-transitory machine-readable medium coupled to the processor and comprising instructions, the instructions, when loaded into the processor and executed, configure the processor to:
identify that a USB element has attached to the USB hub at the USB port;
determine power operations of the USB element;
classify the USB element according to power operations of the USB element;
determine whether to operate the port in either upstream operation or downstream operation based on the determination of the power operations of the USB element;
assign a setting defining whether the port uses either upstream or downstream operation an upstream or downstream setting of the port based upon the classification of the USB element based on the determination of power operations of the USB element
classify the USB element as only a producer of power;
based on the classification of the USB element as only a producer of power, evaluate whether an enumeration process is initiated within a timeout period; and
based on a determination that the enumeration process is not initiated within the timeout period, setting the port as a downstream port.