Re: [PATCH v4 0/2] cpufreq: spacemit: Add cpufreq support for K1 SoC
From: Gong Shuai
Date: Sat Jun 27 2026 - 04:40:38 EST
On 6/26/2026 4:10 PM, Shuwei Wu wrote:
This series enables CPU DVFS for the SpacemiT K1 SoC using the generic
cpufreq-dt driver.
K1 has two CPU clock clusters. The two clusters have separate CPU clocks,
so they are represented as two cpufreq policies: policy0 for CPUs 0-3 and
policy4 for CPUs 4-7.
The CPU voltage rail is shared between the clusters. To model this with two
policies, the OPP entries describe voltage ranges instead of a single fixed
voltage, so the shared regulator can keep the rail within a range acceptable
for the active OPP constraints.
Tested on Banana Pi BPI-F3:
~ # cat /sys/devices/system/cpu/online
0-7
~ # ls /sys/devices/system/cpu/cpufreq/
policy0 policy4
~ # cat /sys/devices/system/cpu/cpufreq/policy0/scaling_driver
cpufreq-dt
~ # cat /sys/devices/system/cpu/cpufreq/policy0/affected_cpus
0 1 2 3
~ # cat /sys/devices/system/cpu/cpufreq/policy4/scaling_driver
cpufreq-dt
~ # cat /sys/devices/system/cpu/cpufreq/policy4/affected_cpus
4 5 6 7
Both policies expose the same OPP frequencies:
~ # cat /sys/devices/system/cpu/cpufreq/policy0/scaling_available_frequencies
614400 819000 1000000 1228800 1600000
~ # cat /sys/devices/system/cpu/cpufreq/policy4/scaling_available_frequencies
614400 819000 1000000 1228800 1600000
For each policy, scaling_setspeed was set to each supported OPP and the
workload was pinned to one CPU covered by that policy with taskset.
CPU0 was used for policy0, and CPU4 was used for policy4. The clock rates below
are from /sys/kernel/debug/clk/clk_summary.
policy0 / CPU0:
----------------------------------------------------------
Frequency | cpu_c0_core_clk | Real (s) | User (s)
(kHz) | (Hz) | |
-------------+-------------------+------------+-----------
1,600,000 | 1,600,000,000 | 1.81 | 1.80
1,228,800 | 1,228,800,000 | 2.37 | 2.37
1,000,000 | 1,000,000,000 | 2.89 | 2.89
819,000 | 819,200,000 | 3.56 | 3.55
614,400 | 614,400,000 | 4.71 | 4.71
----------------------------------------------------------
policy4 / CPU4:
----------------------------------------------------------
Frequency | cpu_c1_core_clk | Real (s) | User (s)
(kHz) | (Hz) | |
-------------+-------------------+------------+-----------
1,600,000 | 1,600,000,000 | 1.81 | 1.80
1,228,800 | 1,228,800,000 | 2.36 | 2.36
1,000,000 | 1,000,000,000 | 2.89 | 2.89
819,000 | 819,200,000 | 3.55 | 3.55
614,400 | 614,400,000 | 4.71 | 4.70
----------------------------------------------------------
Signed-off-by: Shuwei Wu <shuwei.wu@xxxxxxxxxxx>
Hi Shuwei,
Thanks for your work.
I have tested this series on the OrangePi RV2 4GB board on top of
next-20260626, with Vincent's patch for OrangePi RV2 applied.
# uname -a
Linux orangepi-rv2 7.1.0-next-20260626-00005-g66ef697be46d #1 SMP PREEMPT Sat Jun 27 14:53:02 CST 2026 riscv64 GNU/Linux
# ls /sys/devices/system/cpu/cpufreq/
boost policy0 policy4
# cat /sys/devices/system/cpu/cpufreq/policy*/scaling_driver
cpufreq-dt
cpufreq-dt
# cat /sys/devices/system/cpu/cpufreq/policy0/affected_cpus
0 1 2 3
# cat /sys/devices/system/cpu/cpufreq/policy4/affected_cpus
4 5 6 7
# cat /sys/devices/system/cpu/cpufreq/policy*/scaling_available_frequencies
614400 819000 1000000 1228800 1600000
614400 819000 1000000 1228800 1600000
I used the following test script to verify cpufreq functionality:
```bash
#!/bin/sh
echo userspace > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor
echo userspace > /sys/devices/system/cpu/cpufreq/policy4/scaling_governor
echo "--- same frequency test ---"
for freq in 614400 819000 1000000 1228800 1600000; do
echo $freq > /sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed
echo $freq > /sys/devices/system/cpu/cpufreq/policy4/scaling_setspeed
sleep 1
t=$(taskset -c 0 time -f "%e" dd if=/dev/zero of=/dev/null bs=1M count=1000 2>&1 | tail -1)
echo "$freq kHz: ${t}s"
done
echo "--- mixed frequency test ---"
echo 614400 > /sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed
echo 1600000 > /sys/devices/system/cpu/cpufreq/policy4/scaling_setspeed
sleep 1
t0=$(taskset -c 0 time -f "%e" dd if=/dev/zero of=/dev/null bs=1M count=1000 2>&1 | tail -1)
t4=$(taskset -c 4 time -f "%e" dd if=/dev/zero of=/dev/null bs=1M count=1000 2>&1 | tail -1)
echo "p0=614400 p4=1600000 -> cpu0=${t0}s cpu4=${t4}s"
echo 1600000 > /sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed
echo 614400 > /sys/devices/system/cpu/cpufreq/policy4/scaling_setspeed
sleep 1
t0=$(taskset -c 0 time -f "%e" dd if=/dev/zero of=/dev/null bs=1M count=1000 2>&1 | tail -1)
t4=$(taskset -c 4 time -f "%e" dd if=/dev/zero of=/dev/null bs=1M count=1000 2>&1 | tail -1)
echo "p0=1600000 p4=614400 -> cpu0=${t0}s cpu4=${t4}s"
echo 1000000 > /sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed
echo 1228800 > /sys/devices/system/cpu/cpufreq/policy4/scaling_setspeed
sleep 1
t0=$(taskset -c 0 time -f "%e" dd if=/dev/zero of=/dev/null bs=1M count=1000 2>&1 | tail -1)
t4=$(taskset -c 4 time -f "%e" dd if=/dev/zero of=/dev/null bs=1M count=1000 2>&1 | tail -1)
echo "p0=1000000 p4=1228800 -> cpu0=${t0}s cpu4=${t4}s"
```
Results:
# ./test_cpufreq_userspace.sh
--- same frequency test ---
614400 kHz: 0.90s
819000 kHz: 0.67s
1000000 kHz: 0.55s
1228800 kHz: 0.45s
1600000 kHz: 0.34s
--- mixed frequency test ---
p0=614400 p4=1600000 -> cpu0=0.90s cpu4=0.34s
p0=1600000 p4=614400 -> cpu0=0.34s cpu4=0.90s
p0=1000000 p4=1228800 -> cpu0=0.55s cpu4=0.45s
Tested-by: Gong Shuai <gsh517025@xxxxxxxxx> # OrangePi-RV2
Regards,
Shuai
---
Changes in v4:
- Represent K1 as two cpufreq-dt policies, one per CPU clock cluster
- Use OPP voltage ranges for the shared CPU supply
- Link to v3: https://lore.kernel.org/r/20260612-shadow-deps-v3-0-2f3ba88611ff@xxxxxxxxxxx
Changes in v3:
- Add a K1-specific cpufreq driver for the shared-rail, dual-clock topology
- Use one shared CPU OPP table and one cpufreq policy for all CPUs
- Link to v2: https://lore.kernel.org/r/20260410-shadow-deps-v2-0-4e16b8c0f60e@xxxxxxxxxxx
Changes in v2:
- Move OPP tables to dedicated k1-opp.dtsi
- Enable OPP only on BPI-F3 with cpu-supply present
- Link to v1: https://lore.kernel.org/r/20260308-shadow-deps-v1-0-0ceb5c7c07eb@xxxxxxxxxxx
---
Shuwei Wu (2):
cpufreq: dt-platdev: Add SpacemiT K1 SoC to the allowlist
riscv: dts: spacemit: Add cpu scaling for K1 SoC
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 ++
drivers/cpufreq/cpufreq-dt-platdev.c | 2 +
4 files changed, 149 insertions(+), 1 deletion(-)
---
base-commit: 5164e95565d3fd508ca8a95351323f5716dfb695
change-id: 20260307-shadow-deps-3582a78aa756
prerequisite-patch-id: 154bd4f720ce5065d58b988de8f273207b44572e
prerequisite-message-id: <20260206-spacemit-p1-v4-0-8f695d93811e@xxxxxxxxxxxx>
prerequisite-patch-id: 5da3e75b18291a5540d4f66d7a0600fb8975ef62
prerequisite-patch-id: bcf41917414ecef8cf743095d130f6004c32f6a5
prerequisite-patch-id: cfe3800f8c791ec4c63e070af9628e88e0fc31b9
prerequisite-message-id: <20260305-k1-clk-fix-v1-1-abca85d6e266@xxxxxxxxxxx>
prerequisite-patch-id: 7c7fb9f87dba019ece4c97c45750349a7cd28f3a
Best regards,