TPS65988DJ: Dynamic swap the role of the PD controller

John Liu59

Part Number: TPS65988DJ
Other Parts Discussed in Thread: TPS65988

Dear all,

Could you please help check is there method to dynamics to change the roles of the PD controller from Source to Sink or Sink to Source?

My customer want to change the role from sink to source when the notebook from S5 to S0.

I suggest customer to use the 4CC command SWSr, but it seems not work , What conditions should be met before the dynamic changes?

Any other method to try?

Thanks.

over 4 years ago

0 Eric Beljaars over 4 years ago

TI__Mastermind 36751 points

Hi John,

The SWSr and SWSk commands are the correct commands to be using in this use case. I would suggest checking the Port Control (0x29) register to ensure that the PD controller is set up to Process the role swaps you are requesting. However, if the connected device is rejecting the swap then it is not possible to complete that specific role swap with the device you have connected. The PD logs would tell you if this is the case.

Thank you,
Eric

0 John Liu59 over 4 years ago in reply to Eric Beljaars

TI__Intellectual 2735 points

Hi Eric,

Could you please advice which bit of 0x29 register can be used to show the process the role swap?

Is it bit7 "Initiate Swap to Source" to check?

Thanks.

0 Eric Beljaars over 4 years ago in reply to John Liu59

TI__Mastermind 36751 points

Hi John,

I would suggest enabling bit 6 and bit 4 to allow for processing swaps to a source and processing swaps to a sink. This would ensure that the TPS65988 does not reject the 4CC command due to a mismatch in the configuration.

Thank you,
Eric

0 John Liu59 over 4 years ago in reply to Eric Beljaars

TI__Intellectual 2735 points

Hi Eric,

Customer said they send the 4CC command, but didn't success.How to confirm the 4CC command is implemented or not using the register value? or other ways to check it?

Thanks.

0 Eric Beljaars over 4 years ago in reply to John Liu59

TI__Mastermind 36751 points

Hi John,

The best way to check would be through a PD trace. I suspect that the 4CC command to swap power roles is being rejected by the connected device.

Thank you,
Eric

0 John Liu59 over 4 years ago in reply to Eric Beljaars

TI__Intellectual 2735 points

Hi Eric,

Thanks for your reply, let us close the thread, any questions, I will submit new request.

Thanks.

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TPS65988DJ: Dynamic swap the role of the PD controller