esp-hal/esp-hal-common/src/clocks_ll/esp32s3.rs

use crate::clock::CpuClock;

pub(crate) fn set_cpu_clock(cpu_clock_speed: CpuClock) {
    let system_control = unsafe { &*crate::pac::SYSTEM::PTR };

    unsafe {
        system_control
            .sysclk_conf
            .modify(|_, w| w.soc_clk_sel().bits(1));
        system_control.cpu_per_conf.modify(|_, w| {
            w.pll_freq_sel()
                .set_bit()
                .cpuperiod_sel()
                .bits(match cpu_clock_speed {
                    CpuClock::Clock80MHz => 0,
                    CpuClock::Clock160MHz => 1,
                    CpuClock::Clock240MHz => 2,
                })
        });
    }
}