AM5728: Using PRU UART as standard UART under Linux

Robert Finger

Part Number: AM5728

Team,

Our processor SDK doesn't support using the PRU-UART as additional UART in Linux. But could a customer implement this themselves, without running any UART firmware on the PRU? I know interrupt handling is not supported, but couldnt's it be enough to directly access the PRU UART registers from the Cortex A15?

My customer is using all PRUs as additional Ethernet ports, so there is already Ethernet firmware running on the PRUs. It would be good to be able to use the PRU-UART pins as additional UART.

Thanks,
Robert

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

Hi Robert,

They will need a modified UART driver or maybe write a new one to handle this use case.

0 Robert Finger over 8 years ago in reply to Biser Gatchev-XID

TI__Genius 17988 points

Hi Biser,

Please provide more details for the possible solution. Are the PRU-UART registers accessible by A15/Linux? If yes, at which addresses? Is there a detailed register description the customer can look at?

Thanks,
Robert

0 Biser Gatchev-XID over 8 years ago in reply to Robert Finger

TI__Guru**** 393215 points

The PRU UART is described in section 30.1.7 of the AM572x TRM Rev. H. You will find register descriptions there too. The PRU Global memory map is described in section 30.1.4.4.2.

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AM5728: Using PRU UART as standard UART under Linux