Control of Thunderbolt/DisplayPort multiplexor for discrete USB-C graphics processor
An information handling system includes a USB-C port, first and second processors, and a USB-C power delivery controller. The first processor couples to the USB-C port utilizing a first connection type. The second processor couples to the USB-C port utilizing a second connection type. The USB-C power delivery controller includes first registers associated with the first processor and second registers associated with the second processor. The first processor utilizes the first registers to communicate with the USB-C port. The second processor utilizes the second registers to communicate with the USB-C port.
1. An information handling system, comprising:
a USB-C port;
a first processor configured to couple to the USB-C port utilizing a USB/Thunderbolt connection type;
a second processor configured to couple to the USB-C port utilizing a DisplayPort connection type;
a USB-C power delivery controller including first registers and second registers, wherein, at a first time the first processor utilizes only the first registers to communicate with the USB-C port, and at a second time the USB-C power delivery controller shadows the contents of the first registers to the second registers and the second processor utilizes only the first registers to communicate with the USB-C port; and
a retimer including a multiplexor configured to selectably couple one of the first processor and the second processor to the USB-C port;
wherein when an event is associated with the USB/Thunderbolt connection type, the USB-C power delivery controller is further configured to select the first processor, and when the event is associated with the DisplayPort connection type, the USB-C power delivery controller is further configured to select the second processor.
2. The information handling system of claim 1 , wherein the first registers include first command information and first status information, and wherein the second registers include second command and second status information.
3. The information handling system of claim 2 , wherein the USB-C power delivery controller is configured to receive the event from a device coupled to the USB-C port, and to determine whether the event is associated with the USB/Thunderbolt connection type or with the DisplayPort connection type.
4. The information handling system of claim 3 , wherein, when the event is associated with the USB/Thunderbolt connection type, the USB-C power delivery controller is further configured to provide the event to the first processor.
5. The information handling system of claim 4 , wherein, when the event is associated with the DisplayPort connection type, the USB-C power delivery controller is further configured to provide the event to the second processor.
6. The information handling system of claim 1 , wherein the first processor is a general purpose processor.
7. The information handling system of claim 6 , wherein the second processor is a graphics processor.
8. A method, comprising:
providing, in an information handling system, a USB-C port;
selectably coupling a first processor of the information handling system to the USB-C port utilizing a USB/Thunderbolt connection type;
selectably coupling a second processor of the information handling system to the USB-C port utilizing a DisplayPort connection type;
providing, in a USB-C power delivery controller of the information handling system, first registers and second registers;
utilizing, at a first time, only the first registers by the first processor to communicate with the USB-C port;
shadowing, by the USB-C power delivery controller, contents of the first registers to the second registers;
utilizing, at the second time, only the first registers by the second processor to communicate with the USB-C port; and
wherein:
when an event is associated with the USB/Thunderbolt connection type, the method further comprises selecting, by the USB-C power delivery controller, a first input to a multiplexor of a retimer of the information handling system to couple the first processor to the USB-C port; and
when the event is associated with the DisplayPort connection type, the method further comprises selecting, by the USB-C power delivery controller, a second input to the multiplexor to couple the second processor to the USB-C port.
9. The method of claim 8 , wherein the first registers include first command information and first status information, and wherein the second registers include second command and second status information.
10. The method of claim 9 , further comprising:
receiving, by the USB-C power delivery controller, the event from a device coupled to the USB-C port; and
determining whether the event is associated with the USB/Thunderbolt connection type or with the DisplayPort connection type.
11. The method of claim 10 , wherein, when the event is associated with the USB/Thunderbolt connection type, the method further comprises:
providing, by the USB-C power delivery controller, the event to the first processor.
12. The method of claim 11 , wherein, when the event is associated with the DisplayPort connection type, the method further comprises:
providing, by the USB-C power delivery controller, the event to the second processor.
13. The method of claim 8 , wherein the first processor is a general purpose processor.
14. The method of claim 13 , wherein the second processor is a graphics processor.
15. An information handling system, comprising:
a USB-C port;
a general purpose processor configured to couple to the USB-C port utilizing a USB/Thunderbolt connection;
a graphics processor configured to couple to the USB-C port utilizing a DisplayPort connection;
a USB-C power delivery controller including first registers and second registers, wherein, at a first time the general purpose processor utilizes only the first registers to communicate with the USB-C port, and at a second time the USB-C power delivery controller shadows the contents of the first registers to the second registers and the graphics processor utilizes only the first registers to communicate with the USB-C port, the USB-C power delivery controller having an Inter-Integrated Circuit (I2C) interface; and
a retimer including a multiplexor configured to selectably couple one of the general purpose processor and the graphics processor to the USB-C port;
a baseboard management controller coupled to the I2C interface to program the first registers and the second registers;
wherein when an event is associated with the USB/Thunderbolt connection, the USB-C power delivery controller is further configured to select the general purpose processor, and when the event is associated with the DisplayPort connection, the USB-C power delivery controller is further configured to select the graphics processor.
16. The information handling system of claim 1 , wherein the first registers and the second registers are programmed via an Inter-Integrated Circuit (I2C) interface.
17. The method of claim 8 , further comprising:
programming the first registers via an Inter-Integrated Circuit (I2C) interface utilizing prior to the first time; and
programming the second registers via the I2C interface utilizing prior to the second time.