Hi Amit, On Mon, Jun 28, 2021 at 01:55:40PM +0530, Amit Tomer wrote: > Hi, > > > > Do you know the story behind this Ethernet controller? > > > > I just happened to get a board based on the S500 SoC, so I took this > > opportunity to help improving the mainline kernel support, but other > > than that I do not really know much about the hardware history. > > > > > The various > > > receive/transmit descriptor definitions are 99% those defined in > > > drivers/net/ethernet/stmmicro/stmmac/descs.h for the normal descriptor. > > > > That's an interesting observation. I could only assume the vendor did > > not want to reinvent the wheel here, but I cannot say if this is a > > common design scheme or is something specific to STMicroelectronics > > only. > > I am not entirely sure about it but it looks like it *may* only need > to have a glue driver to > connect to DWMAC. >From the RX/TX descriptors perspective, this looks like a Synopsys IP, but the MAC register layout is not similar at all. Thanks to Mani, a request for clarification has been also sent to Actions, but they could not confirm. Hence, at the moment, we do not have clear evidences that it is based on Designware. > For instance, on the U-boot[1] side (S700 is one of 64bit OWL SoC from > actions), we kind of re-uses already > existing DWMAC and provide a glue code, and on the Linux side as well > have some similar implementation (locally). The S700 SoC provides Gigabit ethernet capabilities and I assume the controller is quite different from the 10/100 variant present on S500. As a matter of fact, Actions has confirmed that in the case of S700, the licensing was obtained from a third party IP company, although they were not certain if the provider had previous agreements with Synopsys. Regards, Cristi > Thanks > -Amit. > > [1]: https://source.denx.de/u-boot/u-boot/-/blob/master/drivers/net/dwmac_s700.c
