On 30-11-22, 15:16, Geert Uytterhoeven wrote: > Add operating points for running the Cortex-A55 CPU cores on R-Car S4-8 > at various speeds, up to the maximum supported frequency (1200 MHz). > > R-Car S4-8 has 8 Cortex-A55 cores, grouped in 4 clusters. > CA55 Sub-System 0 (first 2 clusters / CPU cores 0-3) is clocked by Z0φ. > CA55 Sub-System 1 (last 2 clusters / CPU cores 4-7) is clocked by Z1φ. > > As the two sets of clusters are driven by separate clocks, this requires > specifying two separate tables (using the same operating performance > point values), with "opp-shared" to indicate that the CPU cores in each > set share state. > > Based on a patch in the BSP by Tho Vu. > > Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> > --- > To be queued in renesas-devel for v6.3. > > Changes compared to the BSP: > - Use two tables. > > Tested on the Renesas Spider development board by using the CPUfreq > userspace governor, writing the desired CPU clock rate to the CPUfreq > policy's "scaling_setspeed" file in sysfs, verifying the clock rate of > the Z0φ and Z1φ clocks in debugfs, and running the dhrystones benchmark > on the various CPU cores. > > The Linux cpufreq driver creates two policies under > /sys/devices/system/cpu/cpufreq/: "policy0" and "policy4". > > With a single table and "opp-shared", only "policy0" would be created, > and clock Z1φ would never be changed. > With a single table and without "opp-shared", 8 policies would be > created, and the rate of clocks Z0φ and Z1φ would reflect the value for > the last touched CPU core from the corresponding set. > --- > arch/arm64/boot/dts/renesas/r8a779f0.dtsi | 62 +++++++++++++++++++++++ > 1 file changed, 62 insertions(+) Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx> -- viresh
