Linux: TUSB4041IPAPQ1

Hi,

With the generic driver we are able to detect the USB HUB.

After reading the datasheet I think since we are just using DP and DN pins for USB connection and not charging nor our USB ports requires power we don't need to write the I2C/EEPROM registers.

1) Please confirm our understanding is correct or not.
2) Looking at the datasheet we just found that the "Port Used Configuration Register" has default value 1 it should be 0xF as we have four ports connected to the downstream port. Please correct us as looking at the datasheet it is not confirmed whether this value is 1 or 0xF.

Thanks.

Hello,

The TUSB4041 is fully compliant with the USB 2.0 specification; as such, it will automatically load the USB Hub class drivers that are part of the Linux kernel. No additional drivers will be required.

The I2C EEPROM isn't mandatory for the device to operate; it is only used to customize the default configuration.

My apologies if the device specification isn't clear enough. It is intended to assert that the default value for each one of the "used[3:0]" bits is 1. So the default value of the entire "Port Used Configuration Register" is actually 0x0F, which enables all downstream ports.
This is part of the default configuration, so unless you are trying to customize anything else, you will not need an EEPROM or I2C/SMBus master for the device to operate as a USB compliant Hub.

Regards,
Jorge

Hi Jorge,

Thank you for the response and we understand we are not required any specific driver write for this HUB.

We are now able to get the USB host upstream port however still we are not able to detect the USB downstream.

Please let us know how we should debug this issue further.

Regards,
Jorge.

Hi,

Can you provide schematics showing your implementation of the TUSB4041 for me to review it?

Thanks
Jorge