High voltage charging for a portable device

1. A method for charging a portable device using a power supply, the method comprising:

detecting, by the portable device, coupling of the power supply to the portable device;

receiving, by the portable device, identification information from the power supply;

enabling, by the portable device, a communication channel between the power supply and the portable device based on the identification information;

determining, by the portable device, based on additional information received from the power supply, that the power supply is capable of providing voltage of up to 20 V;

sending, by the portable device, a message to the power supply to output a specific voltage; and

receiving, by the portable device, the specific voltage.

2. The method of claim 1 wherein prior to enabling the communication channel, determining, by the portable device, a class associated with the power supply, based on the identification information.

3. The method of claim 1 wherein the communication channel comprises a universal asynchronous receiver/transmitter (UART) transport or universal serial bus (USB) transport.

4. The method of claim 1 wherein the specific voltage is in the range of between 6 V and 20 V.

5. The method of claim 1 wherein the message to the power supply includes information about supplying a specific voltage that is between 6 V and 20 V.

6. The method of claim 1 wherein a first voltage is received, by the portable device, before the specific voltage.

7. The method of claim 6 wherein the first voltage is approximately 5 V.

8. The method of claim 1 wherein prior to enabling the communication channel, determining, by the portable device, a class associated with the power supply, based on the identification information.

9. A method comprising:

receiving, by a power supply, a message from a portable device coupled to the power supply, the message requesting capability information from the power supply over a data communication channel, the data communication channel being separate from a power output signal;

sending, by the power supply, the capability information to the portable device, the capability information including information about whether the power supply is capable of outputting between 6 V and 20 V to the portable device;

receiving, by the power supply from the portable device, another message specifying a value for a voltage to be outputted by the power supply; and

outputting, by the power supply, the specified voltage.

10. The method of claim 9 wherein a first voltage is outputted by the power supply before the specified voltage.

11. The method of claim 10 wherein the first voltage is approximately 5 V.

12. An electronic device comprising:

a first connector including a first plurality of contacts configured to mate with a second connector of an accessory having a second plurality of contacts, wherein at least one contact from the first plurality of contacts is configured to carry power to the electronic device and at least a pair of contacts from the first plurality of contacts are configured to carry data between the electronic device and the accessory;

circuitry coupled to the first connector and configured to:

detect coupling of the accessory;

receive identification information from the accessory;

enable a communication channel with the accessory over the pair of contacts from the first plurality of contacts;

receive capability information from the accessory over the communication channel, the capability information indicating that the accessory is capable of supplying an output voltage between 6V and 20V to the electronic device;

send an instruction to the accessory to output a specific voltage between 6V and 20V; and

receive the specific voltage.

13. The method of claim 12 wherein prior to enabling the communication channel, determining, by the portable device, a class associated with the power supply, based on the identification information.

14. The method of claim 12 wherein the communication channel comprises a universal asynchronous receiver/transmitter (UART) transport or universal serial bus (USB) transport.

15. A power supply comprising:

a connector having a power contact coupleable with an electronic device to deliver power to the electronic device and a pair of data contacts;

a voltage regulator configured to provide an output voltage in the range of 1-20 V via the at least one contact;

a controller coupled to the pair of data contacts and configured to exchange information with the electronic device via the pair of data contacts; and

identification circuitry operable to generate identification information for the power supply, wherein the power supply is configured to:

output a first voltage over the power contact upon connection with the electronic device;

provide identification information to the electronic device;

receive a request from the electronic device over the pair of data contacts, the request being for determining whether the power supply can output a second voltage;

send a response to the request indicating that the power supply can output the second voltage over the power contact;

receiving a request from the electronic device to output the second voltage; and

output the second voltage, the second voltage being higher than the first voltage.

16. The power supply of claim 15 wherein the first voltage is between 1 V and 5 V and the second voltage is between 6 V and 20 V.

17. The method of claim 15 wherein the portable device is configured to determine a class associated with the power supply based on the identification information.

18. The method of claim 15 wherein the identification information is transferred over a communication channel that comprises a universal asynchronous receiver/transmitter (UART) transport or universal serial bus (USB) transport.