arm64: dts: renesas: Add CPU capacity-dmips-mhz
Set the capacity-dmips-mhz for R-Car Gen3 SoCs, that is based on
dhrystone. The average in 10 times of dhrystone result as follows:
r8a7795 SoC (A57x4 + A53x4)
CPU max-freq dhrystone
---------------------------------
A57 1500 MHz
11470943 lps/s
A53 1200 MHz
4798583 lps/s
r8a7796 SoC (A57x2 + A53x4)
CPU max-freq dhrystone
---------------------------------
A57 1500 MHz
11463526 lps/s
A53 1200 MHz
4793276 lps/s
Based on above, capacity-dmips-mhz values are calculated as follows:
r8a7795 SoC
A57 : 1024 / (
11470943 / 1500) * (
11470943 / 1500) = 1024
A53 : 1024 / (
11470943 / 1500) * (
4798583 / 1200) = 535
r8a7796 SoC
A57 : 1024 / (
11463526 / 1500) * (
11463526 / 1500) = 1024
A53 : 1024 / (
11463526 / 1500) * (
4793276 / 1200) = 535
However, since each CPUs have different max frequencies, the final
CPU capacities of A53 are scaled by this difference, the values are
as follows.
[r8a7795 SoC]
$ cat /sys/devices/system/cpu/cpu*/cpu_capacity
1024 <---- CPU capacity of A57
1024
1024
1024
428 <---- CPU capacity of A53
428
428
428
[r8a7796 SoC]
$ cat /sys/devices/system/cpu/cpu*/cpu_capacity
1024 <---- CPU capacity of A57
1024
428 <---- CPU capacity of A53
428
428
428
Signed-off-by: Gaku Inami <gaku.inami.xh@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>