Hi Geert,
Thanks for the feedback.
> Subject: Re: [PATCH 4/4] arm64: dts: renesas: Add HiHope RZ/G2N main
> board support
>
> Hi Biju,
>
> On Tue, Sep 17, 2019 at 3:12 PM Biju Das <biju.das@xxxxxxxxxxxxxx> wrote:
> > Basic support for the HiHope RZ/G2N main board:
> > - Memory,
> > - Main crystal,
> > - Serial console
> >
> > Signed-off-by: Biju Das <biju.das@xxxxxxxxxxxxxx>
>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
>
> One question below...
>
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/renesas/r8a774b1-hihope-rzg2n.dts
> > @@ -0,0 +1,26 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Device Tree Source for the HiHope RZ/G2N main board
> > + *
> > + * Copyright (C) 2019 Renesas Electronics Corp.
> > + */
> > +
> > +/dts-v1/;
> > +#include "r8a774b1.dtsi"
> > +#include "hihope-common.dtsi"
> > +
> > +/ {
> > + model = "HopeRun HiHope RZ/G2N main board based on r8a774b1";
> > + compatible = "hoperun,hihope-rzg2n", "renesas,r8a774b1";
> > +
> > + memory@48000000 {
> > + device_type = "memory";
> > + /* first 128MB is reserved for secure area. */
> > + reg = <0x0 0x48000000 0x0 0x78000000>;
> > + };
> > +
> > + memory@480000000 {
> > + device_type = "memory";
> > + reg = <0x4 0x80000000 0x0 0x80000000>;
> > + };
> > +};
>
> So both the HiHope RZ/G2M and RZ/G2N boards have 4 GiB of RAM, while
> the latter has a narrower memory bus, so it must be wired differently?
RZ/G2M is LPDDR4-3200 with 32 bits × 2 channels, where as RZ/G2N is LPDDR4-3200 with 32 bits × 1 channel.
RZ/G2M can have split mapping where as RZ/G2N can have only linear mapping.
Regards,
Biju
