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

From: Aurelien Jarno <aurelien@aurel32.net>
To: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Cc: Minda Chen <minda.chen@starfivetech.com>,
	Rick Chen <rick@andestech.com>, Leo <ycliang@andestech.com>,
	Lukasz Tekieli <tekieli.lukasz@gmail.com>,
	Chanho Park <chanho61.park@samsung.com>,
	Shiji Yang <yangshiji66@outlook.com>,
	Shengyu Qu <wiagn233@outlook.com>,
	Seung-Woo Kim <sw0312.kim@samsung.com>,
	E Shattow <lucent@gmail.com>,
	u-boot@lists.denx.de
Subject: Re: [PATCH v2 4/6] board: starfive: support Milk-V Mars board
Date: Mon, 1 Apr 2024 17:28:28 +0200	[thread overview]
Message-ID: <ZgrSnExL1iTg8nSC@aurel32.net> (raw)
In-Reply-To: <b5af9050-aa50-4445-9de3-4e5f368621b7@canonical.com>

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@10100000 and usb@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";
};

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

Aurelien

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                     http://aurel32.net