Re: [PATCH v3 11/12] arm64: dts: exynos: gs101: define USI8 with I2C configuration

Sam Protsenko
2024-01-17T16:12:40Z

On Wed, Jan 17, 2024 at 9:08 AM Tudor Ambarus <tudor.ambarus@linaro.org> wrote:
>
>
>
> On 1/16/24 18:03, Sam Protsenko wrote:
> >> USI8 CONFIG register comes with a 0x0 reset value, meaning that USI8
> >> doesn't have a default protocol (I2C, SPI, UART) at reset. Thus the
> >> selection of the protocol is intentionally left for the board dts file.
> >>
> >> Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
> >> ---
> >> v3: reorder usi8 clock order (thanks Andre'!). Did not make any
> >> difference at testing as the usi driver treats the clocks in bulk.
> >> v2:
> >> - identify and use gate clocks instead of dividers
> >> - move cells and pinctrl properties from dts to dtsi
> >> - move IRQ type constant on the previous line
> >>
> >> arch/arm64/boot/dts/exynos/google/gs101.dtsi | 29 ++++++++++++++++++++
> >> 1 file changed, 29 insertions(+)
> >>
> >> diff --git a/arch/arm64/boot/dts/exynos/google/gs101.dtsi b/arch/arm64/boot/dts/exynos/google/gs101.dtsi
> >> index 6aa25cc4676e..f14a24628d04 100644
> >> --- a/arch/arm64/boot/dts/exynos/google/gs101.dtsi
> >> +++ b/arch/arm64/boot/dts/exynos/google/gs101.dtsi
> >> @@ -352,6 +352,35 @@ pinctrl_peric0: pinctrl@10840000 {
> >> interrupts = <GIC_SPI 625 IRQ_TYPE_LEVEL_HIGH 0>;
> >> };
> >>
> >> + usi8: usi@109700c0 {
> >> + compatible = "google,gs101-usi",
> >> + "samsung,exynos850-usi";
> >> + reg = <0x109700c0 0x20>;
> >> + ranges;
> >> + #address-cells = <1>;
> >> + #size-cells = <1>;
> >> + clocks = <&cmu_peric0 CLK_GOUT_PERIC0_CLK_PERIC0_USI8_USI_CLK>,
> >> + <&cmu_peric0 CLK_GOUT_PERIC0_PERIC0_TOP0_IPCLK_7>;
> >> + clock-names = "pclk", "ipclk";
> >> + samsung,sysreg = <&sysreg_peric0 0x101c>;
> > I'd also add samsung,mode for the "default" USI mode here, just to
> > avoid providing it later in the board's dts. But that's a matter of
> > taste I guess.
> >
>
> USI8 CONFIG register comes with a 0x0 reset value, meaning that USI8
> doesn't have a default protocol (I2C, SPI, UART) at reset. Thus the
> selection of the protocol is intentionally left for the board dts file.
>
> I wanted to emphasize that USI8 doesn't have any HW defaults and its
> mode must be chosen by each particular board.
>
> I mentioned the same in the commit message, please tell if you feel it
> needs updating.
>

No, thanks, everything LGTM, I already added my R-b tag above.

> Cheers,
> ta