• Biju Das's avatar
    arm64: dts: renesas: r8a774a1: Add CPU capacity-dmips-mhz · 5f524949
    Biju Das authored
    Set the capacity-dmips-mhz for RZ/G2M(r8a774a1) SoC, that is based on
    dhrystone.
    
    Based on work done by Gaku Inami <gaku.inami.xw@bp.renesas.com> for
    r8a7796 SoC.
    
    The average dhrystone result for 5 iterations is as below:
    
    r8a774a1 SoC (CA57x2 + CA53x4)
      CPU   max-freq   dhrystone
      ---------------------------------
      CA57   1500 MHz  11428571 lps/s
      CA53   1200 MHz   5000000 lps/s
    
    From this, CPU capacity-dmips-mhz for CA57 and CA53 are calculated
    as follows:
    
    r8a774a1 SoC
      CA57 : 1024 / (11428571 / 1500) * (11428571 / 1500) = 1024
      CA53 : 1024 / (11428571 / 1500) * ( 5000000 / 1200) =  560
    
    Since each CPUs have different max frequencies, the final CPU
    capacities of A53 scaled by the above difference is as below
    
    $ cat /sys/devices/system/cpu/cpu*/cpu_capacity
    1024
    1024
    448
    448
    448
    448
    Signed-off-by: default avatarBiju Das <biju.das@bp.renesas.com>
    Signed-off-by: default avatarSimon Horman <horms+renesas@verge.net.au>
    5f524949
r8a774a1.dtsi 68.5 KB