embassy/embassy-stm32/src/rcc/wba.rs
2023-09-16 04:04:45 +02:00

185 lines
4.2 KiB
Rust

use stm32_metapac::rcc::vals::{Pllsrc, Sw};
use crate::pac::{FLASH, RCC};
use crate::rcc::{set_freqs, Clocks};
use crate::time::Hertz;
/// HSI speed
pub const HSI_FREQ: Hertz = Hertz(16_000_000);
/// LSI speed
pub const LSI_FREQ: Hertz = Hertz(32_000);
pub use crate::pac::pwr::vals::Vos as VoltageScale;
pub use crate::pac::rcc::vals::{Hpre as AHBPrescaler, Ppre as APBPrescaler};
#[derive(Copy, Clone)]
pub enum ClockSrc {
HSE(Hertz),
HSI16,
}
#[derive(Clone, Copy, Debug)]
pub enum PllSrc {
HSE(Hertz),
HSI16,
}
impl Into<Pllsrc> for PllSrc {
fn into(self) -> Pllsrc {
match self {
PllSrc::HSE(..) => Pllsrc::HSE32,
PllSrc::HSI16 => Pllsrc::HSI16,
}
}
}
impl Into<Sw> for ClockSrc {
fn into(self) -> Sw {
match self {
ClockSrc::HSE(..) => Sw::HSE32,
ClockSrc::HSI16 => Sw::HSI16,
}
}
}
trait Div {
fn div(&self) -> u8;
}
impl Div for APBPrescaler {
fn div(&self) -> u8 {
match self {
Self::DIV1 => 1,
Self::DIV2 => 2,
Self::DIV4 => 4,
Self::DIV8 => 8,
Self::DIV16 => 16,
_ => unreachable!(),
}
}
}
impl Div for AHBPrescaler {
fn div(&self) -> u8 {
match self {
Self::DIV1 => 1,
Self::DIV2 => 2,
Self::DIV4 => 4,
Self::DIV8 => 8,
Self::DIV16 => 16,
_ => unreachable!(),
}
}
}
#[derive(Copy, Clone)]
pub struct Config {
pub mux: ClockSrc,
pub ahb_pre: AHBPrescaler,
pub apb1_pre: APBPrescaler,
pub apb2_pre: APBPrescaler,
pub apb7_pre: APBPrescaler,
}
impl Default for Config {
fn default() -> Self {
Self {
mux: ClockSrc::HSI16,
ahb_pre: AHBPrescaler::DIV1,
apb1_pre: APBPrescaler::DIV1,
apb2_pre: APBPrescaler::DIV1,
apb7_pre: APBPrescaler::DIV1,
}
}
}
pub(crate) unsafe fn init(config: Config) {
let sys_clk = match config.mux {
ClockSrc::HSE(freq) => {
RCC.cr().write(|w| w.set_hseon(true));
while !RCC.cr().read().hserdy() {}
freq.0
}
ClockSrc::HSI16 => {
RCC.cr().write(|w| w.set_hsion(true));
while !RCC.cr().read().hsirdy() {}
HSI_FREQ.0
}
};
// TODO make configurable
let power_vos = VoltageScale::RANGE1;
// states and programming delay
let wait_states = match power_vos {
VoltageScale::RANGE1 => match sys_clk {
..=32_000_000 => 0,
..=64_000_000 => 1,
..=96_000_000 => 2,
..=100_000_000 => 3,
_ => 4,
},
VoltageScale::RANGE2 => match sys_clk {
..=8_000_000 => 0,
..=16_000_000 => 1,
_ => 2,
},
};
FLASH.acr().modify(|w| {
w.set_latency(wait_states);
});
RCC.cfgr1().modify(|w| {
w.set_sw(config.mux.into());
});
RCC.cfgr2().modify(|w| {
w.set_hpre(config.ahb_pre.into());
w.set_ppre1(config.apb1_pre.into());
w.set_ppre2(config.apb2_pre.into());
});
RCC.cfgr3().modify(|w| {
w.set_ppre7(config.apb7_pre.into());
});
let ahb_freq: u32 = sys_clk / config.ahb_pre.div() as u32;
let (apb1_freq, apb1_tim_freq) = match config.apb1_pre.div() {
1 => (ahb_freq, ahb_freq),
div => {
let freq = ahb_freq / div as u32;
(freq, freq * 2)
}
};
let (apb2_freq, apb2_tim_freq) = match config.apb2_pre.div() {
1 => (ahb_freq, ahb_freq),
div => {
let freq = ahb_freq / div as u32;
(freq, freq * 2)
}
};
let (apb7_freq, _apb7_tim_freq) = match config.apb7_pre.div() {
1 => (ahb_freq, ahb_freq),
div => {
let freq = ahb_freq / div as u32;
(freq, freq * 2)
}
};
set_freqs(Clocks {
sys: Hertz(sys_clk),
ahb1: Hertz(ahb_freq),
ahb2: Hertz(ahb_freq),
ahb4: Hertz(ahb_freq),
apb1: Hertz(apb1_freq),
apb2: Hertz(apb2_freq),
apb7: Hertz(apb7_freq),
apb1_tim: Hertz(apb1_tim_freq),
apb2_tim: Hertz(apb2_tim_freq),
});
}