Re: [PATCH 09/13] arm64: dts: exynos: gs101: update USI UART to use peric0 clocks

Sam Protsenko
2023-12-14T15:43:04Z

On Thu, Dec 14, 2023 at 4:53 AM Tudor Ambarus <tudor.ambarus@linaro.org> wrote:
>
> Get rid of the dummy clock and start using the cmu_peric0 clocks
> for the usi_uart and serial_0 nodes.
>
> Tested the serial at 115200, 1000000 and 3000000 baudrates,
> everthing went fine.
>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
> ---
> arch/arm64/boot/dts/exynos/google/gs101.dtsi | 14 ++++----------
> 1 file changed, 4 insertions(+), 10 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/exynos/google/gs101.dtsi b/arch/arm64/boot/dts/exynos/google/gs101.dtsi
> index d0b0ad70c6ba..ffb7b4d89a8c 100644
> --- a/arch/arm64/boot/dts/exynos/google/gs101.dtsi
> +++ b/arch/arm64/boot/dts/exynos/google/gs101.dtsi
> @@ -180,14 +180,6 @@ HERA_CPU_SLEEP: cpu-hera-sleep {
> };
> };
>
> - /* TODO replace with CCF clock */
> - dummy_clk: clock-3 {
> - compatible = "fixed-clock";
> - #clock-cells = <0>;
> - clock-frequency = <12345>;
> - clock-output-names = "pclk";
> - };
> -
> /* ect node is required to be present by bootloader */
> ect {
> };
> @@ -369,7 +361,8 @@ usi_uart: usi@10a000c0 {
> ranges;
> #address-cells = <1>;
> #size-cells = <1>;
> - clocks = <&dummy_clk>, <&dummy_clk>;
> + clocks = <&cmu_peric0 CLK_GOUT_PERIC0_CLK_PERIC0_USI0_UART_CLK>,
> + <&cmu_peric0 CLK_DOUT_PERIC0_USI0_UART>;

Why using DIV clock here? Usually all leaf clocks are GATE clocks (at
least it's so in Exynos850).

> clock-names = "pclk", "ipclk";
> samsung,sysreg = <&sysreg_peric0 0x1020>;
> samsung,mode = <USI_V2_UART>;
> @@ -381,7 +374,8 @@ serial_0: serial@10a00000 {
> reg-io-width = <4>;
> interrupts = <GIC_SPI 634
> IRQ_TYPE_LEVEL_HIGH 0>;
> - clocks = <&dummy_clk 0>, <&dummy_clk 0>;
> + clocks = <&cmu_peric0 CLK_GOUT_PERIC0_CLK_PERIC0_USI0_UART_CLK>,
> + <&cmu_peric0 CLK_DOUT_PERIC0_USI0_UART>;

Ditto.

> clock-names = "uart", "clk_uart_baud0";
> samsung,uart-fifosize = <256>;
> status = "disabled";
> --
> 2.43.0.472.g3155946c3a-goog
>