Re: [PATCH v2 2/2] riscv: dts: spacemit: Add cpu scaling for K1 SoC

Anand Moon
2026-04-14T13:25:34Z

Hi Shuwei,

On Fri, 10 Apr 2026 at 13:30, Shuwei Wu <shuwei.wu@mailbox.org> wrote:
>
> Add Operating Performance Points (OPP) tables and CPU clock properties
> for the two clusters in the SpacemiT K1 SoC.
>
> Also assign the CPU power supply (cpu-supply) for the Banana Pi BPI-F3
> board to fully enable CPU DVFS.
>
> Signed-off-by: Shuwei Wu <shuwei.wu@mailbox.org>
>
> ---
> Changes in v2:
> - Add k1-opp.dtsi with OPP tables for both CPU clusters
> - Assign CPU supplies and include OPP table for Banana Pi BPI-F3
> ---
> arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts | 35 +++++++-
> arch/riscv/boot/dts/spacemit/k1-opp.dtsi | 105 ++++++++++++++++++++++++
> arch/riscv/boot/dts/spacemit/k1.dtsi | 8 ++
> 3 files changed, 147 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> index 444c3b1e6f44..3780593f610d 100644
> --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> @@ -5,6 +5,7 @@
>
> #include "k1.dtsi"
> #include "k1-pinctrl.dtsi"
> +#include "k1-opp.dtsi"
>
> / {
> model = "Banana Pi BPI-F3";
> @@ -86,6 +87,38 @@ &combo_phy {
> status = "okay";
> };
>
> +&cpu_0 {
> + cpu-supply = <&buck1_3v45>;
> +};
> +
> +&cpu_1 {
> + cpu-supply = <&buck1_3v45>;
> +};
> +
> +&cpu_2 {
> + cpu-supply = <&buck1_3v45>;
> +};
> +
> +&cpu_3 {
> + cpu-supply = <&buck1_3v45>;
> +};
> +
> +&cpu_4 {
> + cpu-supply = <&buck1_3v45>;
> +};
> +
> +&cpu_5 {
> + cpu-supply = <&buck1_3v45>;
> +};
> +
> +&cpu_6 {
> + cpu-supply = <&buck1_3v45>;
> +};
> +
> +&cpu_7 {
> + cpu-supply = <&buck1_3v45>;
> +};
> +
> &emmc {
> bus-width = <8>;
> mmc-hs400-1_8v;
> @@ -201,7 +234,7 @@ pmic@41 {
> dldoin2-supply = <&buck5>;
>
> regulators {
> - buck1 {
> + buck1_3v45: buck1 {
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <3450000>;
> regulator-ramp-delay = <5000>;
> diff --git a/arch/riscv/boot/dts/spacemit/k1-opp.dtsi b/arch/riscv/boot/dts/spacemit/k1-opp.dtsi
> new file mode 100644
> index 000000000000..768ae390686d
> --- /dev/null
> +++ b/arch/riscv/boot/dts/spacemit/k1-opp.dtsi
> @@ -0,0 +1,105 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +
> +/ {
> + cluster0_opp_table: opp-table-cluster0 {
> + compatible = "operating-points-v2";
> + opp-shared;
> +
> + opp-614400000 {
> + opp-hz = /bits/ 64 <614400000>;
> + opp-microvolt = <950000>;
> + clock-latency-ns = <200000>;
> + };
> +
> + opp-819000000 {
> + opp-hz = /bits/ 64 <819000000>;
> + opp-microvolt = <950000>;
> + clock-latency-ns = <200000>;
> + };
> +
> + opp-1000000000 {
> + opp-hz = /bits/ 64 <1000000000>;
> + opp-microvolt = <950000>;
> + clock-latency-ns = <200000>;
> + };
> +
> + opp-1228800000 {
> + opp-hz = /bits/ 64 <1228800000>;
> + opp-microvolt = <950000>;
> + clock-latency-ns = <200000>;
> + };
> +
> + opp-1600000000 {
> + opp-hz = /bits/ 64 <1600000000>;
> + opp-microvolt = <1050000>;
> + clock-latency-ns = <200000>;
> + };
> + };
> +
> + cluster1_opp_table: opp-table-cluster1 {
> + compatible = "operating-points-v2";
> + opp-shared;
> +
> + opp-614400000 {
> + opp-hz = /bits/ 64 <614400000>;
> + opp-microvolt = <950000>;
> + clock-latency-ns = <200000>;
> + };
> +
> + opp-819000000 {
> + opp-hz = /bits/ 64 <819000000>;
> + opp-microvolt = <950000>;
> + clock-latency-ns = <200000>;
> + };
> +
> + opp-1000000000 {
> + opp-hz = /bits/ 64 <1000000000>;
> + opp-microvolt = <950000>;
> + clock-latency-ns = <200000>;
> + };
> +
> + opp-1228800000 {
> + opp-hz = /bits/ 64 <1228800000>;
> + opp-microvolt = <950000>;
> + clock-latency-ns = <200000>;
> + };
> +
> + opp-1600000000 {
> + opp-hz = /bits/ 64 <1600000000>;
> + opp-microvolt = <1050000>;
> + clock-latency-ns = <200000>;
> + };
> + };
> +};
> +
> +&cpu_0 {
> + operating-points-v2 = <&cluster0_opp_table>;
> +};
> +
> +&cpu_1 {
> + operating-points-v2 = <&cluster0_opp_table>;
> +};
> +
> +&cpu_2 {
> + operating-points-v2 = <&cluster0_opp_table>;
> +};
> +
> +&cpu_3 {
> + operating-points-v2 = <&cluster0_opp_table>;
> +};
> +
> +&cpu_4 {
> + operating-points-v2 = <&cluster1_opp_table>;
> +};
> +
> +&cpu_5 {
> + operating-points-v2 = <&cluster1_opp_table>;
> +};
> +
> +&cpu_6 {
> + operating-points-v2 = <&cluster1_opp_table>;
> +};
> +
> +&cpu_7 {
> + operating-points-v2 = <&cluster1_opp_table>;
> +};
> diff --git a/arch/riscv/boot/dts/spacemit/k1.dtsi b/arch/riscv/boot/dts/spacemit/k1.dtsi
> index 529ec68e9c23..bdd109b81730 100644
> --- a/arch/riscv/boot/dts/spacemit/k1.dtsi
> +++ b/arch/riscv/boot/dts/spacemit/k1.dtsi
> @@ -54,6 +54,7 @@ cpu_0: cpu@0 {
> compatible = "spacemit,x60", "riscv";
> device_type = "cpu";
> reg = <0>;
> + clocks = <&syscon_apmu CLK_CPU_C0_CORE>;
> riscv,isa = "rv64imafdcbv_zicbom_zicbop_zicboz_zicntr_zicond_zicsr_zifencei_zihintpause_zihpm_zfh_zba_zbb_zbc_zbs_zkt_zvfh_zvkt_sscofpmf_sstc_svinval_svnapot_svpbmt";
> riscv,isa-base = "rv64i";
> riscv,isa-extensions = "i", "m", "a", "f", "d", "c", "b", "v", "zicbom",
> @@ -84,6 +85,7 @@ cpu_1: cpu@1 {
> compatible = "spacemit,x60", "riscv";
> device_type = "cpu";
> reg = <1>;
> + clocks = <&syscon_apmu CLK_CPU_C0_CORE>;

Based on the Spacemit kernel source, the k1-x_opp_table.dtsi file
defines several additional clocks for the Operating Performance Points
(OPP) table:

clocks = <&ccu CLK_CPU_C0_ACE>, <&ccu CLK_CPU_C1_ACE>, <&ccu CLK_CPU_C0_TCM>,
<&ccu CLK_CCI550>, <&ccu CLK_PLL3>, <&ccu
CLK_CPU_C0_HI>, <&ccu CLK_CPU_C1_HI>;
clock-names = "ace0","ace1","tcm","cci","pll3", "c0hi", "c1hi";

These hardware clocks are also explicitly registered in the APMU clock driver
via the k1_ccu_apmu_hws array, confirming their availability for frequency
and voltage scaling on the K1-X SoC.

static struct clk_hw *k1_ccu_apmu_hws[] = {
[CLK_CCI550] = &cci550_clk.common.hw,
[CLK_CPU_C0_HI] = &cpu_c0_hi_clk.common.hw,
[CLK_CPU_C0_CORE] = &cpu_c0_core_clk.common.hw,
[CLK_CPU_C0_ACE] = &cpu_c0_ace_clk.common.hw,
[CLK_CPU_C0_TCM] = &cpu_c0_tcm_clk.common.hw,
[CLK_CPU_C1_HI] = &cpu_c1_hi_clk.common.hw,
[CLK_CPU_C1_CORE] = &cpu_c1_core_clk.common.hw,
[CLK_CPU_C1_ACE] = &cpu_c1_ace_clk.common.hw,

Yes, it is possible to add these clocks for DVFS to work correctly,
provided they are managed by the appropriate driver and declared in
the Device Tree (DT).

Thanks
-Anand