Re: [PATCH v2 09/10] ARM: dts: r8a7742-iwg21m: Add iWave RZ/G1H Qseven SOM

From: Lad, Prabhakar
Date: Mon May 04 2020 - 10:20:47 EST


Hi Geert,

Thank you for the review.

On Mon, May 4, 2020 at 2:01 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
>
> Hi Prabhakar,
>
> On Sun, May 3, 2020 at 11:48 PM Lad Prabhakar
> <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> wrote:
> > Add support for iWave RZ/G1H Qseven System On Module.
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > Reviewed-by: Marian-Cristian Rotariu <marian-cristian.rotariu.rb@xxxxxxxxxxxxxx>
>
> Thanks for your patch!
>
> > --- /dev/null
> > +++ b/arch/arm/boot/dts/r8a7742-iwg21m.dtsi
> > @@ -0,0 +1,53 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Device Tree Source for the iWave RZ/G1H Qseven SOM
> > + *
> > + * Copyright (C) 2020 Renesas Electronics Corp.
> > + */
> > +
> > +#include "r8a7742.dtsi"
> > +#include <dt-bindings/gpio/gpio.h>
> > +
> > +/ {
> > + compatible = "iwave,g21m", "renesas,r8a7742";
> > +
> > + memory@40000000 {
> > + device_type = "memory";
> > + reg = <0 0x40000000 0 0x40000000>;
> > + };
> > +
> > + memory@200000000 {
> > + device_type = "memory";
> > + reg = <2 0x00000000 0 0x20000000>;
>
> According to the schematics, the second bank is also 1 GiB, so the
> reg length should be 0x40000000.
>
Agreed will fix that.

> > + };
>
> > +&pfc {
> > + mmc1_pins: mmc1 {
> > + groups = "mmc1_data4", "mmc1_ctrl";
> > + function = "mmc1";
> > + };
> > +};
> > +
> > +&mmcif1 {
> > + pinctrl-0 = <&mmc1_pins>;
> > + pinctrl-names = "default";
> > +
> > + vmmc-supply = <&reg_3p3v>;
> > + bus-width = <4>;
> > + non-removable;
> > + status = "okay";
> > +};
>
> The eMMC has an 8-bit data path. Is there any specific reason you use
> bus-width = <4>, and the "mmc1_data4" pin group?
>
MMC1_DATA7 is shared with VI1_CLK, so instead of limiting to only one
device when using 8-bit just switched to 4bit mode so that both the
peripherals can be used.

Cheers,
--Prabhakar

> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds