[PATCH v2 4/6] board: starfive: support Milk-V Mars board

[Minda Chen]

> 
> On 4/1/24 17:28, Aurelien Jarno wrote:
> > On 2024-03-28 17:01, Heinrich Schuchardt wrote:
> >> On 24.03.24 16:00, Aurelien Jarno wrote:
> >>> On 2024-03-21 19:11, Heinrich Schuchardt wrote:
> >>>> The differences between the Milk-V Mars board and the VisionFive 2
> >>>> board are small enough that we can support both using the same U-Boot
> build.
> >>>>
> >>>> * The model and compatible property are taken from proposed Linux
> patches.
> >>>> * The EEPROM is atmel,24c02 according to the vendor U-Boot.
> >>>> * The second Ethernet port is not available.
> >>>
> >>>   From the device tree that have been submitted to the kernel [1] it
> >>> seems another difference is that there is a CD gpio for mmc1.
> >>
> >> Thank you for reviewing.
> >>
> >> On all of Milk-V Mars, VisionFive 2 1.2B, and 1.3A I see GPIO 41
> >> level changing when removing or inserting an SD card using U-Boot
> >> command 'gpio status -a'. So this seems not to be Milk-V specific.
> >>
> >> Could you, please, check.
> >
> > This already have been answered by others, thanks.
> >
> >>>   From the schematics, it also seems that the usb0 port is not in
> >>> peripheral mode, but in host mode. That said on the submitted kernel
> >>> device tree it seems simply disabled.
> >>
> >> All three blue-colored USB 3.0 ports are able to read an SD-card in U-Boot.
> >>
> >> The black port provides 5V but I could not make it work.
> >>
> >> On the schema I found:
> >>
> >> USB20: Do not support OTG mode and AVSS_USB0-AVSS_USB2 attached to
> ground.
> >>
> >> Could you, please, specify which node in the device-tree you want to
> >> disable. I cannot see anything disabled for usb at 10100000 and usb at 0 in
> >> the kernel device-tree.
> >
> > Disclaimer, I have no such board, but I remember people on IRC trying
> > to use the device tree from the VF2 on a Milk-V Mars and getting an
> > error with the USB being in a wrong mode.
> >
> > The difference I have noticed is not a node but the dr_mode property:
> >
> > &usb0 {
> >          dr_mode = "peripheral";
> >          status = "okay";
> > };
> 
> Thanks Aurelien for the explanation.
> 
> The node usb at 10100000 (aka usb0) does not exist in the U-Boot
> VisionFive2 device-tree, yet. There isn't any dr_mode property either.
> 
> We will have to consider this node once we merge the Linux device-tree.
> 
> Best regards
> 
> Heinrich
> 
usb at 10100000 is cadence usb controller. In VF2, dr mode is usb peripheral and 
seldom used in u-boot. So the cadence usb wrapper codes not in uboot upstream.
I don't know the dr mode in milkv 7110 board. But if it its dr mode is host, I think I
need develop cadence usb wrapper code upstream.

Minda 
> >
> > This does not appear on the patches submitted on the Linux side for
> > the MilkV Mars.
> >
> > Aurelien
> >