RE: [PATCH net-next v3 1/2] net/ethernet/realtek: Add Realtek automotive PCIe driver code

From: Justin Lai
Date: Mon Aug 21 2023 - 23:28:03 EST


> > But I2C, SPI, MDIO are connected to the SoC through this chip's
> > external pins, not on the PCIe bus.
>
> Thanks, that was the information i was trying to get at.
>
> > Actually, there is the other function in the PCIe GMAC(Multiple
> > function) to manage the registers of Switch Core. Should they be
> > integrated into the MFD driver?
>
> Can you cleanly attach another PCI driver to those functions?

Yes, they could be attached individually

> You need to use an MFD when there is a single top level addressable block of
> hardware which has multiple functions. Thank of an I2C device, which has a
> single address on the bus, but multiple functions.
> Access to that one address needs to be shared via multiple drivers. The MFD
> framework provides the glue to share access to the hardware.
>
> However, PCI identification and addressing is more flexible. So long as they are
> separate PCI functions, you should be able to load two drivers and not have
> problems. Then you don't need an MFD.

Thank you very much for your comments and time for review.