On Thu, Sep 10, 2020 at 6:25 PM Matthias Brugger <matthias.bgg@xxxxxxxxx> wrote:
>
> Hi,
>
> On 10/09/2020 10:43, Hsin-Yi Wang wrote:
> > Set uart iotype to mmio32 to make earlycon work with stdout-path.
> >
> > Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
> > ---
> > arch/arm64/boot/dts/mediatek/mt8173.dtsi | 8 ++++++++
> > 1 file changed, 8 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/mediatek/mt8173.dtsi b/arch/arm64/boot/dts/mediatek/mt8173.dtsi
> > index 5e046f9d48ce9..ca6ea71f5f435 100644
> > --- a/arch/arm64/boot/dts/mediatek/mt8173.dtsi
> > +++ b/arch/arm64/boot/dts/mediatek/mt8173.dtsi
> > @@ -613,6 +613,8 @@ uart0: serial@11002000 {
> > interrupts = <GIC_SPI 83 IRQ_TYPE_LEVEL_LOW>;
> > clocks = <&pericfg CLK_PERI_UART0_SEL>, <&pericfg CLK_PERI_UART0>;
> > clock-names = "baud", "bus";
> > + reg-io-width = <4>;
>
> Why do we need that, we have
> device->port.iotype = UPIO_MEM32;
> in early_mtk8250_setup(). That should do the job already.
>
>
But if we don't change in dts, we would see
[ 0.000000] earlycon: mtk8250 at MMIO 0x0000000011002000 (options '115200n8')
instead of
[ 0.000000] earlycon: mtk8250 at MMIO32 0x0000000011002000 (options
'115200n8')
Perhaps we should move the pr_info part in earlycon_init() after
match->setup(). Since setup may change iotype. What do you think?
> > + reg-shift = <2>;
>
> Can't we just add
> device->port.regshift = 2;
> to early_mtk8250_setup()? I think that would be a cleaner solution. As the
> serial device is the same for all SoCs, I don't expect any regression here.
>
> CCing Eddie to correct me, if I'm wrong :)
>
> Regards,
> Matthias
>
> > status = "disabled";
> > };
> >
> > @@ -623,6 +625,8 @@ uart1: serial@11003000 {
> > interrupts = <GIC_SPI 84 IRQ_TYPE_LEVEL_LOW>;
> > clocks = <&pericfg CLK_PERI_UART1_SEL>, <&pericfg CLK_PERI_UART1>;
> > clock-names = "baud", "bus";
> > + reg-io-width = <4>;
> > + reg-shift = <2>;
> > status = "disabled";
> > };
> >
> > @@ -633,6 +637,8 @@ uart2: serial@11004000 {
> > interrupts = <GIC_SPI 85 IRQ_TYPE_LEVEL_LOW>;
> > clocks = <&pericfg CLK_PERI_UART2_SEL>, <&pericfg CLK_PERI_UART2>;
> > clock-names = "baud", "bus";
> > + reg-io-width = <4>;
> > + reg-shift = <2>;
> > status = "disabled";
> > };
> >
> > @@ -643,6 +649,8 @@ uart3: serial@11005000 {
> > interrupts = <GIC_SPI 86 IRQ_TYPE_LEVEL_LOW>;
> > clocks = <&pericfg CLK_PERI_UART3_SEL>, <&pericfg CLK_PERI_UART3>;
> > clock-names = "baud", "bus";
> > + reg-io-width = <4>;
> > + reg-shift = <2>;
> > status = "disabled";
> > };
> >
> >
