[PATCH 2/4] board: add support for Milk-V Mars CM

Tue Apr 30 11:59:52 CEST 2024

On Tue, Apr 30, 2024 at 12:18 AM Heinrich Schuchardt
<heinrich.schuchardt at canonical.com> wrote:
>
> On 30.04.24 00:46, E Shattow wrote:
> > On Sun, Apr 28, 2024 at 9:13 AM Emil Renner Berthing
> > <emil.renner.berthing at canonical.com> wrote:
> >>
> >> Heinrich Schuchardt wrote:
> >>> We already support the VisionFive 2 and the Milk-V Mars board by
> >>> patching the VisionFive 2 device tree. With this patch the same
> >>> is done for the Milk-V Mars CM.
> >>
> >> Hi Heinrich.
> >>
> >> Thanks for the patch. As far as I can tell the Milk-V documentation[1] is
> >> pretty consistent in calling the version without eMMC "Milk-V Mars CM Lite"
> >> and the version with eMMC just "Milk-V Mars CM". So I'd prefer the model,
> >> compatible and filenames suggested below.
> >>
> >> [1]: https://milkv.io/docs/mars/compute-module/introduction#design-philosophy
> >>
> >
> > Are there any actual differences that need representation in the dtb
> > file for downstream OS different from Milk-V Mars to Milk-V Mars CM
> > (or CM Lite)?
> >
> > I did find this vendor repo commit "kernel: dts reconfig sdio0 for
> > SDCard version"
> > https://github.com/milkv-mars/mars-buildroot-sdk/commit/042ea06598995db99ddbbbb252ee439c42b9c1a9
> > but it does not seem necessary in mainline Linux, SD Card is working
> > without changes.
> >
> > It was necessary for U-Boot and the Mars CM Lite with SD Card to apply
> > s/GPIO62/GPIO22/ as in the vendor commit "u-boot: configure sdio0 as
> > mars-cm sdcard version"
> > https://github.com/milkv-mars/mars-buildroot-sdk/commit/880a249518f72ecf1e2947dfeb2c66e5035fce90
>
> This is what is patched in fdt_fixup_marc().

That's the Mars fixup with a conditional for the s/GPIO62/GPIO22/ of
CM Lite;  which Linux seems not to mind either way so long as this was
done at the U-Boot phase, it is functional for eMMC/SD mmc access with
unmodified visionfive2 1.3b dtb (GPIO62 pinmux) from Linux.

It is not clear to me why in vendor U-Boot this is s/GPIO62/GPIO22/
but in vendor Linux kernel this is s/GPIO62/GPIO24/ ? It seems not
needed (in Linux).

>
> >
> > Then also there is some mention about PMIC and renamed i2c reference,
> > already obsolete. That's all, is there more to it? Possibly a dtb for
> > Mars is enough to also be used on Mars CM and Mars Lite?
>
> Looking at the schematics the biggest difference between the Mars and
> the Mars CM (Lite) is on the USB side. The Mars board has USB 3.0 via a
> PCIe lane and a VIA VL805/806 while the Mars CM has USB directly via the
> SoC.
>
> To add USB support for the Mars CM we will need an adapted device-tree.

Mars also needs this direct-to-SoC USB support, as its USB ports are a
mix of VL805 and directly via the SoC. This can be the same for Mars
and Mars CM/Lite.

See this photo from
https://milkv.io/docs/mars/getting-started/bootloader what highlights
this direct SoC USB port of Milk-V Mars:
https://milkv.io/assets/images/mars-usb-port-a-b48fe1ff1003539d42bf5e1dde1725a3.jpg

The over-current errata
https://doc-en.rvspace.org/VisionFive2/DG_USB/JH7110_SDK/usb_overcurrent_debug.html
suggests "please modify the above settings during the U-Boot phase".

-E

>
> Best regards
>
> Heinrich
> >
> >>> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
> >>> ---
> >>>   board/starfive/visionfive2/spl.c              | 27 ++++++++++++++++++-
> >>>   .../visionfive2/starfive_visionfive2.c        | 11 +++++++-
> >>>   2 files changed, 36 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/board/starfive/visionfive2/spl.c b/board/starfive/visionfive2/spl.c
> >>> index 45848db6d8b..bb0f28d7aad 100644
> >>> --- a/board/starfive/visionfive2/spl.c
> >>> +++ b/board/starfive/visionfive2/spl.c
> >>> @@ -129,6 +129,29 @@ void spl_fdt_fixup_mars(void *fdt)
> >>>        }
> >>>   }
> >>>
> >>> +void spl_fdt_fixup_marc(void *fdt)
> >>> +{
> >>> +     const char *compat;
> >>> +     const char *model;
> >>> +
> >>> +     spl_fdt_fixup_mars(fdt);
> >>> +
> >>> +     if (!get_mmc_size_from_eeprom()) {
> >>> +             int offset;
> >>> +
> >>> +             model = "Milk-V Mars CM SDCard";
> >>
> >> "Milk-V Mars CM Lite"
> >>
> >>> +             compat = "milkv,mars-cm-sdcard\0starfive,jh7110";
> >>
> >> "milkv,mars-cm-lite\0starfive,jh7110"
> >>
> >>> +
> >>> +             offset = fdt_path_offset(fdt, "/soc/pinctrl/mmc0-pins/mmc0-pins-rest");
> >>> +             fdt_setprop_u32(fdt, offset, "pinmux", 0xff130016);
> >>> +     } else {
> >>> +             model = "Milk-V Mars CM eMMC";
> >>
> >> "Milk-V Mars CM"
> >>
> >>> +             compat = "milkv,mars-cm-emmc\0starfive,jh7110";
> >>
> >> "milkv,mars-cm\0starfive,jh7110"
> >>
> >>> +     }
> >>> +     fdt_setprop(fdt, fdt_path_offset(fdt, "/"), "compatible", compat, sizeof(compat));
> >>> +     fdt_setprop_string(fdt, fdt_path_offset(fdt, "/"), "model", model);
> >>> +}
> >>> +
> >>>   void spl_fdt_fixup_version_a(void *fdt)
> >>>   {
> >>>        static const char compat[] = "starfive,visionfive-2-v1.2a\0starfive,jh7110";
> >>> @@ -236,7 +259,9 @@ void spl_perform_fixups(struct spl_image_info *spl_image)
> >>>                pr_err("Can't read EEPROM\n");
> >>>                return;
> >>>        }
> >>> -     if (!strncmp(product_id, "MARS", 4)) {
> >>> +     if (!strncmp(product_id, "MARC", 4)) {
> >>> +             spl_fdt_fixup_marc(spl_image->fdt_addr);
> >>> +     } else if (!strncmp(product_id, "MARS", 4)) {
> >>>                spl_fdt_fixup_mars(spl_image->fdt_addr);
> >>>        } else if (!strncmp(product_id, "VF7110", 6)) {
> >>>                version = get_pcb_revision_from_eeprom();
> >>> diff --git a/board/starfive/visionfive2/starfive_visionfive2.c b/board/starfive/visionfive2/starfive_visionfive2.c
> >>> index a86bca533b2..be6ca85b030 100644
> >>> --- a/board/starfive/visionfive2/starfive_visionfive2.c
> >>> +++ b/board/starfive/visionfive2/starfive_visionfive2.c
> >>> @@ -17,6 +17,10 @@
> >>>   DECLARE_GLOBAL_DATA_PTR;
> >>>   #define JH7110_L2_PREFETCHER_BASE_ADDR               0x2030000
> >>>   #define JH7110_L2_PREFETCHER_HART_OFFSET     0x2000
> >>> +#define FDTFILE_MILK_V_MARC_SD \
> >>> +     "starfive/jh7110-milkv-mars-cm-sdcard.dtb"
> >>
> >> "starfive/jh7110-milkv-mars-cm-lite.dtb"
> >>
> >>> +#define FDTFILE_MILK_V_MARC_MMC \
> >>> +     "starfive/jh7110-milkv-mars-cm-emmc.dtb"
> >>
> >> "starfive/jh7110-milkv-mars-cm.dtb"
> >>
> >>>   #define FDTFILE_MILK_V_MARS \
> >>>        "starfive/jh7110-milkv-mars.dtb"
> >>>   #define FDTFILE_VISIONFIVE2_1_2A \
> >>> @@ -61,7 +65,12 @@ static void set_fdtfile(void)
> >>>                log_err("Can't read EEPROM\n");
> >>>                return;
> >>>        }
> >>> -     if (!strncmp(product_id, "MARS", 4)) {
> >>> +     if (!strncmp(product_id, "MARC", 4)) {
> >>> +             if (get_mmc_size_from_eeprom())
> >>> +                     fdtfile = FDTFILE_MILK_V_MARC_MMC;
> >>> +             else
> >>> +                     fdtfile = FDTFILE_MILK_V_MARC_SD;
> >>> +     } else if (!strncmp(product_id, "MARS", 4)) {
> >>>                fdtfile = FDTFILE_MILK_V_MARS;
> >>>        } else if (!strncmp(product_id, "VF7110", 6)) {
> >>>                version = get_pcb_revision_from_eeprom();
> >>> --
> >>> 2.43.0
> >>>
> >>>
>