Re: [PATCH 2/3] arm64: dts: amlogic: t7: Add UART controllers nodes

[Xianwei Zhao]

Hi Ronald,

On 2026/4/15 19:16, Ronald Claveau wrote:
> Add device tree nodes for UART B through F (serial@7a000 to
> serial@82000), completing the UART controller description for the T7
> SoC. Each node includes the peripheral clock.
>
> While at it, move the uart_a node to its correct position in the
> bus address order (0x78000) to comply with the DT requirement that
> nodes be sorted by their reg address. Complete the
> uart_a node with its peripheral clock (CLKID_SYS_UART_A) and the
> associated clock-names, matching the vendor default clock assignment,
> consistent with the other UART nodes.
>
> Signed-off-by: Ronald Claveau<linux-kernel-dev@xxxxxxxx>
> ---
>   arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi | 61 +++++++++++++++++++++++++----
>   1 file changed, 54 insertions(+), 7 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi b/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
> index 531931cc1437c..56b015cfbd6d1 100644
> --- a/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
> +++ b/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
> @@ -577,13 +577,6 @@ gpio_intc: interrupt-controller@4080 {
>                                          <10 11 12 13 14 15 16 17 18 19 20 21>;
>                          };
>
> -                       uart_a: serial@78000 {
> -                               compatible = "amlogic,t7-uart", "amlogic,meson-s4-uart";
> -                               reg = <0x0 0x78000 0x0 0x18>;
> -                               interrupts = <GIC_SPI 168 IRQ_TYPE_EDGE_RISING>;
> -                               status = "disabled";
> -                       };
> -
>                          gp0: clock-controller@8080 {
>                                  compatible = "amlogic,t7-gp0-pll";
>                                  reg = <0x0 0x8080 0x0 0x20>;
> @@ -713,6 +706,60 @@ pwm_ao_cd: pwm@60000 {
>                                  status = "disabled";
>                          };
>
> +                       uart_a: serial@78000 {
> +                               compatible = "amlogic,t7-uart", "amlogic,meson-s4-uart";
> +                               reg = <0x0 0x78000 0x0 0x18>;
> +                               interrupts = <GIC_SPI 168 IRQ_TYPE_EDGE_RISING>;
> +                               clocks = <&xtal>, <&clkc_periphs CLKID_SYS_UART_A>, <&xtal>;
> +                               clock-names = "xtal", "pclk", "baud";

The xtal clock is defined in the board-level DTS file, while it is 
referenced in the DTSI file, which seems a bit unusual.

On other chips, the xtal clock is usually defined directly in the DTSI file.

> +                               status = "disabled";
> +                       };
> +
> +                       uart_b: serial@7a000 {
> +                               compatible = "amlogic,t7-uart", "amlogic,meson-s4-uart";
> +                               reg = <0x0 0x7a000 0x0 0x18>;
> +                               interrupts = <GIC_SPI 169 IRQ_TYPE_EDGE_RISING>;
> +                               clocks = <&xtal>, <&clkc_periphs CLKID_SYS_UART_B>, <&xtal>;
> +                               clock-names = "xtal", "pclk", "baud";
> +                               status = "disabled";
> +                       };
> +
> +                       uart_c: serial@7c000 {
> +                               compatible = "amlogic,t7-uart", "amlogic,meson-s4-uart";
> +                               reg = <0x0 0x7c000 0x0 0x18>;
> +                               interrupts = <GIC_SPI 170 IRQ_TYPE_EDGE_RISING>;
> +                               clocks = <&xtal>, <&clkc_periphs CLKID_SYS_UART_C>, <&xtal>;
> +                               clock-names = "xtal", "pclk", "baud";
> +                               status = "disabled";
> +                       };
> +
> +                       uart_d: serial@7e000 {
> +                               compatible = "amlogic,t7-uart", "amlogic,meson-s4-uart";
> +                               reg = <0x0 0x7e000 0x0 0x18>;
> +                               interrupts = <GIC_SPI 171 IRQ_TYPE_EDGE_RISING>;
> +                               clocks = <&xtal>, <&clkc_periphs CLKID_SYS_UART_D>, <&xtal>;
> +                               clock-names = "xtal", "pclk", "baud";
> +                               status = "disabled";
> +                       };
> +
> +                       uart_e: serial@80000 {
> +                               compatible = "amlogic,t7-uart", "amlogic,meson-s4-uart";
> +                               reg = <0x0 0x80000 0x0 0x18>;
> +                               interrupts = <GIC_SPI 172 IRQ_TYPE_EDGE_RISING>;
> +                               clocks = <&xtal>, <&clkc_periphs CLKID_SYS_UART_E>, <&xtal>;
> +                               clock-names = "xtal", "pclk", "baud";
> +                               status = "disabled";
> +                       };
> +
> +                       uart_f: serial@82000 {
> +                               compatible = "amlogic,t7-uart", "amlogic,meson-s4-uart";
> +                               reg = <0x0 0x82000 0x0 0x18>;
> +                               interrupts = <GIC_SPI 173 IRQ_TYPE_EDGE_RISING>;
> +                               clocks = <&xtal>, <&clkc_periphs CLKID_SYS_UART_F>, <&xtal>;
> +                               clock-names = "xtal", "pclk", "baud";
> +                               status = "disabled";
> +                       };
> +
>                          sd_emmc_a: mmc@88000 {
>                                  compatible = "amlogic,t7-mmc", "amlogic,meson-axg-mmc";
>                                  reg = <0x0 0x88000 0x0 0x800>;