[PATCH v2] riscv: dts: spacemit: k1-orangepi-rv2: Add cpu scaling

[PATCH v2] riscv: dts: spacemit: k1-orangepi-rv2: Add cpu scaling

[Vincent Legoll]

Enable CPU DVFS on OrangePi RV2

Signed-off-by: Vincent Legoll <vincent.legoll@gmail.com>
---
Tested on a 2GB RAM OrangePi RV2 board, patch applied over
spacemit/for-next + Shuwei Wu's V3 series.

On Void linux (musl libc):

uname -a
Linux opirv2 7.1.0-rc1-00043-gb860bca13be4 #14 SMP PREEMPT Sat Jun 13 
11:02:13 CEST 2026 riscv64 GNU/Linux

awk --version | head -1
GNU Awk 5.3.2, API 4.0

echo userspace > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor

echo 1600000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
time awk 'BEGIN{for(i=0;i<1000000;i++){}}'
real    0m0.300s
user    0m0.299s
sys     0m0.001s

echo 1228800 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
time awk 'BEGIN{for(i=0;i<1000000;i++){}}'
real    0m0.432s
user    0m0.429s
sys     0m0.004s

echo 1000000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
time awk 'BEGIN{for(i=0;i<1000000;i++){}}'
real    0m0.476s
user    0m0.476s
sys     0m0.001s

echo 819000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
time awk 'BEGIN{for(i=0;i<1000000;i++){}}'
real    0m0.582s
user    0m0.581s
sys     0m0.001s

echo 614400 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
time awk 'BEGIN{for(i=0;i<1000000;i++){}}'
real    0m0.778s
user    0m0.773s
sys     0m0.005s

Changes in v2:
- Fix indentation with TABs
Feedback from Yixun Lan (dlan)
- sort includes in alphabetical order
- use b4
- Link to v1: https://patch.msgid.link/f031e13e-d9f5-414a-b90e-a3d5a60b8d05@online.fr
---
 arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts | 35 +++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts b/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
index 7c49bce427f3..2c2542e02d6a 100644
--- a/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
+++ b/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
@@ -7,6 +7,7 @@
 /dts-v1/;
 
 #include "k1.dtsi"
+#include "k1-opp.dtsi"
 #include "k1-pinctrl.dtsi"
 
 / {
@@ -80,6 +81,38 @@ &combo_phy {
 	status = "okay";
 };
 
+&cpu_0 {
+	cpu-supply = <&buck1_0v9>;
+};
+
+&cpu_1 {
+	cpu-supply = <&buck1_0v9>;
+};
+
+&cpu_2 {
+	cpu-supply = <&buck1_0v9>;
+};
+
+&cpu_3 {
+	cpu-supply = <&buck1_0v9>;
+};
+
+&cpu_4 {
+	cpu-supply = <&buck1_0v9>;
+};
+
+&cpu_5 {
+	cpu-supply = <&buck1_0v9>;
+};
+
+&cpu_6 {
+	cpu-supply = <&buck1_0v9>;
+};
+
+&cpu_7 {
+	cpu-supply = <&buck1_0v9>;
+};
+
 &emmc {
 	bus-width = <8>;
 	mmc-hs400-1_8v;
@@ -162,7 +195,7 @@ pmic@41 {
 		dldoin2-supply = <&buck5>;
 
 		regulators {
-			buck1 {
+			buck1_0v9: buck1 {
 				regulator-min-microvolt = <500000>;
 				regulator-max-microvolt = <3450000>;
 				regulator-ramp-delay = <5000>;

---
base-commit: 32cb211965ea0ba0ab8568959f006c7fa10e9f23
change-id: 20260615-k1-cpufreq-orangepi-rv2-5ece985163cd

Best regards,
--  
Vincent Legoll <vincent.legoll@gmail.com>

Re: [PATCH v2] riscv: dts: spacemit: k1-orangepi-rv2: Add cpu scaling

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [High] The `buck1` CPU supply regulator has a dangerously high maximum voltage constraint of 3.45V, risking permanent CPU damage under DVFS.
- [Low] The patch includes `k1-opp.dtsi`, which does not exist in the source tree, leading to a fatal device tree build error.
--

commit 6c23623ea2ead11420af84821e27659f9fd1622e
Author: Vincent Legoll <vincent.legoll@gmail.com>

riscv: dts: spacemit: k1-orangepi-rv2: Add cpu scaling

This commit enables CPU DVFS on the OrangePi RV2 by including an OPP
device tree file and binding the CPU supply to a regulator.

> diff --git a/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts b/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
> index 7c49bce427f30..2c2542e02d6a8 100644
> --- a/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
> +++ b/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
> @@ -7,6 +7,7 @@
>  /dts-v1/;
>  
>  #include "k1.dtsi"
> +#include "k1-opp.dtsi"

[Severity: Low]
Does the k1-opp.dtsi file exist in the source tree? Including a missing file
will cause the device tree compiler to fail with a no such file or directory
error, immediately breaking the build.

>  #include "k1-pinctrl.dtsi"
>  
>  / {

[ ... ]

> @@ -80,6 +81,38 @@ &combo_phy {
>  	status = "okay";
>  };
>  
> +&cpu_0 {
> +	cpu-supply = <&buck1_0v9>;
> +};

[ ... ]

> @@ -162,7 +195,7 @@ pmic@41 {
>  		dldoin2-supply = <&buck5>;
>  
>  		regulators {
> -			buck1 {
> +			buck1_0v9: buck1 {
>  				regulator-min-microvolt = <500000>;
>  				regulator-max-microvolt = <3450000>;

[Severity: High]
Is this maximum voltage constraint safe for the CPU under DVFS? The
regulator allows up to 3.45V, and by actively binding it to the CPU as
cpu-supply in this patch, cpufreq or the regulator framework could request
voltages much higher than the typical ~0.9V core voltage. Could this risk
permanent overvoltage damage to the CPU if an invalid OPP table or userspace
override occurs?

>  				regulator-ramp-delay = <5000>;

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260615-k1-cpufreq-orangepi-rv2-v2-1-237f006e580b@gmail.com?part=1