Re: [PATCH v4 0/2] cpufreq: spacemit: Add cpufreq support for K1 SoC

On Fri, 2026-06-26 at 16:10, 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 <[email protected]>
> ---
> 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/[email protected]
> 
> 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/[email protected]
> 
> 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/[email protected]
> 

Tested on bananapi-F3 and Musebook, works fine.

Tested-by: Milan P. Stanić <[email protected]>

> ---