Skip to content
  • Pi-Cheng Chen's avatar
    cpufreq: mediatek: Add MT8173 cpufreq driver · 1453863f
    Pi-Cheng Chen authored
    
    
    Mediatek MT8173 is an ARMv8 based quad-core (2*Cortex-A53 and
    2*Cortex-A72) SoC with duall clusters. For each cluster, two voltage
    inputs, Vproc and Vsram are supplied by two regulators. For the big
    cluster, two regulators come from different PMICs. In this case, when
    scaling voltage inputs of the cluster, the voltages of two regulator
    inputs need to be controlled by software explicitly under the SoC
    specific limitation:
    
    	100mV < Vsram - Vproc < 200mV
    
    which is called 'voltage tracking' mechanism. And when scaling the
    frequency of cluster clock input, the input MUX need to be parented to
    another "intermediate" stable PLL first and reparented to the original
    PLL once the original PLL is stable at the target frequency. This patch
    implements those mechanisms to enable CPU DVFS support for Mediatek
    MT8173 SoC.
    
    Signed-off-by: default avatarPi-Cheng Chen <pi-cheng.chen@linaro.org>
    Acked-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    1453863f