TPS92682-Q1: TPS92682-Q1 example on Linux

Hello Loc,

Our expert for this part is currently on vacation and he will respond to all queries once he returns.

Best,

Pedro Arango Ramirez. 

Hi Mr.Tuan,

So it seems that I need to implement the new driver to work with the TPS92682-Q1 in the Linux side.

Then may I ask that can you help share the workflow/sequence or any sample implement/configuration then I can use as a references for my implement

Thank you very much. 

Best regards,

Loc.

Loc,

This is soft-ware related and I'll let my colleage answer this.

Thanks Tuan

Hi Mr.Lee,

I've check your information follow the https://www.ti.com/lit/ug/sluaac4/sluaac4.pdf?ts=1689609927320&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTPS92682-Q1&_ticdt=MTY4OTgzMjY2NHwwMTg3NTQ4NzdkMGUwMDFiZTQyNzU0OGNmYTc4MDUwNmYwMDc0MDY3MDBiZDB8R0ExLjIuMTQzOTI4MDkzLjE2ODA3NTAzNzk

and the https://www.ti.com/lit/ds/symlink/tps92518-q1.pdf?ts=1616427736994&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTPS92518-Q1&_ticdt=MTY4OTgzMTQ0NXwwMTg3NTQ4NzdkMGUwMDFiZTQyNzU0OGNmYTc4MDUwNmYwMDc0MDY3MDBiZDB8R0ExLjIuMTQzOTI4MDkzLjE2ODA3NTAzNzk for TPS92518 as a reference.

With this document, I can create a SPI frame but I still not able to read/write the register of the TPS92682. 

So could you please help give me some more details how I can do that in Linux kernel driver? I'm currently using the J721e with SDK 8.5 and the TPS92682 is on my SPI5 bus.

Best regards,

Loc.

Hi Lee,

I've created a simple driver to read/write the register under Linux.

And I can capture the frame as below:

Write 0 to register 0x00 after POR

Write 1 to register 0x00

Write 2 to register 0x00

Read register 0x00

Write 3 to register 0x00

But it seems that the result is not match with the example here: https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/935120/tps92682-q1-what-would-be-the-response-frame-in-case-of-write-frame-following-read-frame/3454888#3454888 

And after config the register, the tps92682 still not working as my expectation. Seem something wrong here.

Could you please help take a look on this? 

Best regards,

Loc.

Hi Lee,

I'm using the tps92682 in my custom board, it's not the TI's EVM 

So I'd like to confirm: Even if the MISO is not correct, does it effect the MOSI line? I mean with the command frame that I sent, does the register is written? Are there any other method I can verify?

For these type of questions, where hardware implementation is suspect, it is best to refer you to my colleague Tuan Tran who can assist you further.

Yes. Thank you very much for you support.

Hi Tuan Tran74, Could you please help me check that? Thank you

Loc,

Do you have a 10K pull up on MISO?  Please send us a copy of your schematic to check.

Thanks Tuan

Hi Tuan,

I'd like to share the schematic here.

Please lease help check

Hi Loc,

Be sure that the EN pin is Hi and pulled up for the part to be enabled and SSN does not need a pull-up register.  Are you able to read from any of the register the registers?  What happens if you try to read register 00h?  You should get a value of 3C.  

Please use an oscilloscope to verify your reads and write with the timing in section 7.5 of the data sheet.  Please show a scope capture of a read to register 00.  Then a write to register 00 to a value of 0C to see of your reads and write follows the timing requirements in Section 7.5 of the data sheet.

We recommend that you get our evaluation board to help you with your development.

Thanks Tuan