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

From: Samuel Holland

Date: Sun Mar 08 2026 - 13:59:57 EST

Hi Shuwei,

On 2026-03-07 11:17 PM, Shuwei Wu 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@xxxxxxxxxxx>
> ---
> arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts | 34 +++++++++-
> arch/riscv/boot/dts/spacemit/k1.dtsi | 86 +++++++++++++++++++++++++
> 2 files changed, 119 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..b87bf9d51cb1 100644
> --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> @@ -86,6 +86,38 @@ &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 +233,7 @@ 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.dtsi b/arch/riscv/boot/dts/spacemit/k1.dtsi
> index 529ec68e9c23..5c7bb5d85fc0 100644
> --- a/arch/riscv/boot/dts/spacemit/k1.dtsi
> +++ b/arch/riscv/boot/dts/spacemit/k1.dtsi
> @@ -54,6 +54,8 @@ cpu_0: cpu@0 {
> compatible = "spacemit,x60", "riscv";
> device_type = "cpu";
> reg = <0>;
> + clocks = <&syscon_apmu CLK_CPU_C0_CORE>;
> + operating-points-v2 = <&cluster0_opp_table>;
> 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 +86,8 @@ cpu_1: cpu@1 {
> compatible = "spacemit,x60", "riscv";
> device_type = "cpu";
> reg = <1>;
> + clocks = <&syscon_apmu CLK_CPU_C0_CORE>;
> + operating-points-v2 = <&cluster0_opp_table>;
> 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",
> @@ -114,6 +118,8 @@ cpu_2: cpu@2 {
> compatible = "spacemit,x60", "riscv";
> device_type = "cpu";
> reg = <2>;
> + clocks = <&syscon_apmu CLK_CPU_C0_CORE>;
> + operating-points-v2 = <&cluster0_opp_table>;
> 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",
> @@ -144,6 +150,8 @@ cpu_3: cpu@3 {
> compatible = "spacemit,x60", "riscv";
> device_type = "cpu";
> reg = <3>;
> + clocks = <&syscon_apmu CLK_CPU_C0_CORE>;
> + operating-points-v2 = <&cluster0_opp_table>;
> 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",
> @@ -174,6 +182,8 @@ cpu_4: cpu@4 {
> compatible = "spacemit,x60", "riscv";
> device_type = "cpu";
> reg = <4>;
> + clocks = <&syscon_apmu CLK_CPU_C1_CORE>;
> + operating-points-v2 = <&cluster1_opp_table>;
> 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",
> @@ -204,6 +214,8 @@ cpu_5: cpu@5 {
> compatible = "spacemit,x60", "riscv";
> device_type = "cpu";
> reg = <5>;
> + clocks = <&syscon_apmu CLK_CPU_C1_CORE>;
> + operating-points-v2 = <&cluster1_opp_table>;
> 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",
> @@ -234,6 +246,8 @@ cpu_6: cpu@6 {
> compatible = "spacemit,x60", "riscv";
> device_type = "cpu";
> reg = <6>;
> + clocks = <&syscon_apmu CLK_CPU_C1_CORE>;
> + operating-points-v2 = <&cluster1_opp_table>;
> 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",
> @@ -264,6 +278,8 @@ cpu_7: cpu@7 {
> compatible = "spacemit,x60", "riscv";
> device_type = "cpu";
> reg = <7>;
> + clocks = <&syscon_apmu CLK_CPU_C1_CORE>;
> + operating-points-v2 = <&cluster1_opp_table>;
> 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",
> @@ -339,6 +355,76 @@ osc_32k: clock-32k {
> };
> };
>
> + 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>;

What is the initial voltage set by firmware before Linux boots? If it is 1.05V,
this is fine, but if the default is 950mV, then you cannot enable the OPP table
in the SoC .dtsi file. Boards other than the BananaPi F3 are missing the
cpu-supply property, so they won't raise the CPU voltage before switching to the
higher frequency. The usual solution is to put the OPP table (or at least the
OPPs that require a higher voltage) in a separate .dtsi file, and only include
that file from boards that provide the cpu-supply.

Regards,
Samuel