Need COM1 and COM2 implementation details
According to the UP Squared Professional block diagram for the E3950, serial ports COM1 and COM2 are "behind" an F81216 LPC to UART chip. The F81216 data sheet shows the F81216 as a single LPC to UART chip.
Are the COM1 and COM2 ports part of the F81216 or are they really behind the F81216 and separate F81438G chip implementations ? Do the COM1 and COM2 ports look to be direct PCIe devices (that is, the F81216 is transparent) or does the F81216 look like some type of bridge or adapter ? If so, what does the bridge/adapter look like (ISA, XBUS, etc.) ? Thanks.
Comments
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@VMSEAGLE
F81216 is a super IO, it provides 4 UART ports through LPC interface.
F81438G is a Transceiver, it handles UART to RS232/RS422/RS485 protocol for COM interface -
Thank you.
How do these devices appear in the PCIe address space ? Are the transceivers directly addressable and look like PCIe direct attach or is there something that needs to be done through the LPC interface ?
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What are base addresses for the LPC and UART chips ?
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@VMSEAGLE
Can you explain your question details? F81216 is not a PCIe device, so there is no PCIe address space.
The SoC just use F81216 LPC to driver UART, see the block diagram below
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How is the F81216 addressed and what addresses are associated with it ? What is the base address for the F81216 ? I need to determine how the F81216 appears in the SoC address space and how it will look to drivers when they scan looking for that hardware.
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The specification for the FINTEK F81216 document several Global Control registers. The register at index 07h is the Logic Device Select Register which is used to select one of the UARTs. There is also a Vendor ID Register at indexes 23h and 24h. What is the base address to access this range of registers ? I need to be able to read and write the FINTEK F81216 Global Control registers.
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@VMSEAGLE
Maybe this can help you, linux driver source code for FINTEK LPC to 4 UART
https://github.com/torvalds/linux/blob/master/drivers/tty/serial/8250/8250_fintek.c
