use core::convert::TryFrom;
use super::{set_freqs, Clocks};
use crate::pac::flash::vals::Latency;
use crate::pac::rcc::vals::*;
use crate::pac::{FLASH, RCC};
use crate::time::Hertz;
pub const HSI_FREQ: Hertz = Hertz(8_000_000);
#[non_exhaustive]
#[derive(Default)]
pub struct Config {
pub hse: Option<Hertz>,
pub sys_ck: Option<Hertz>,
pub hclk: Option<Hertz>,
pub pclk1: Option<Hertz>,
pub pclk2: Option<Hertz>,
pub adcclk: Option<Hertz>,
pub pllxtpre: bool,
pub ls: super::LsConfig,
}
pub(crate) unsafe fn init(config: Config) {
let pllxtpre_div = if config.pllxtpre { 2 } else { 1 };
let pllsrcclk = config.hse.map(|hse| hse.0 / pllxtpre_div).unwrap_or(HSI_FREQ.0 / 2);
let sysclk = config.sys_ck.map(|sys| sys.0).unwrap_or(pllsrcclk);
let pllmul = sysclk / pllsrcclk;
let (pllmul_bits, real_sysclk) = if pllmul == 1 {
(None, config.hse.map(|hse| hse.0).unwrap_or(HSI_FREQ.0))
} else {
let pllmul = core::cmp::min(core::cmp::max(pllmul, 1), 16);
(Some(pllmul as u8 - 2), pllsrcclk * pllmul)
};
assert!(real_sysclk <= 72_000_000);
let hpre_bits = config
.hclk
.map(|hclk| match real_sysclk / hclk.0 {
0 => unreachable!(),
1 => 0b0111,
2 => 0b1000,
3..=5 => 0b1001,
6..=11 => 0b1010,
12..=39 => 0b1011,
40..=95 => 0b1100,
96..=191 => 0b1101,
192..=383 => 0b1110,
_ => 0b1111,
})
.unwrap_or(0b0111);
let hclk = if hpre_bits >= 0b1100 {
real_sysclk / (1 << (hpre_bits - 0b0110))
} else {
real_sysclk / (1 << (hpre_bits - 0b0111))
};
assert!(hclk <= 72_000_000);
let ppre1_bits = config
.pclk1
.map(|pclk1| match hclk / pclk1.0 {
0 => unreachable!(),
1 => 0b011,
2 => 0b100,
3..=5 => 0b101,
6..=11 => 0b110,
_ => 0b111,
})
.unwrap_or(0b011);
let ppre1 = 1 << (ppre1_bits - 0b011);
let pclk1 = hclk / u32::try_from(ppre1).unwrap();
let timer_mul1 = if ppre1 == 1 { 1 } else { 2 };
assert!(pclk1 <= 36_000_000);
let ppre2_bits = config
.pclk2
.map(|pclk2| match hclk / pclk2.0 {
0 => unreachable!(),
1 => 0b011,
2 => 0b100,
3..=5 => 0b101,
6..=11 => 0b110,
_ => 0b111,
})
.unwrap_or(0b011);
let ppre2 = 1 << (ppre2_bits - 0b011);
let pclk2 = hclk / u32::try_from(ppre2).unwrap();
let timer_mul2 = if ppre2 == 1 { 1 } else { 2 };
assert!(pclk2 <= 72_000_000);
FLASH.acr().write(|w| {
w.set_latency(if real_sysclk <= 24_000_000 {
Latency::WS0
} else if real_sysclk <= 48_000_000 {
Latency::WS1
} else {
Latency::WS2
});
w.set_prftbe(true);
});
#[cfg(not(rcc_f100))]
let (usbpre, _usbclk_valid) = match (config.hse, pllmul_bits, real_sysclk) {
(Some(_), Some(_), 72_000_000) => (false, true),
(Some(_), Some(_), 48_000_000) => (true, true),
_ => (true, false),
};
let apre_bits: u8 = config
.adcclk
.map(|adcclk| match pclk2 / adcclk.0 {
0..=2 => 0b00,
3..=4 => 0b01,
5..=7 => 0b10,
_ => 0b11,
})
.unwrap_or(0b11);
let apre = (apre_bits + 1) << 1;
let adcclk = pclk2 / unwrap!(u32::try_from(apre));
assert!(adcclk <= 14_000_000);
if config.hse.is_some() {
RCC.cr().modify(|w| w.set_hseon(true));
while !RCC.cr().read().hserdy() {}
}
if let Some(pllmul_bits) = pllmul_bits {
let pllctpre_flag: u8 = if config.pllxtpre { 1 } else { 0 };
RCC.cfgr()
.modify(|w| w.set_pllxtpre(Pllxtpre::from_bits(pllctpre_flag)));
RCC.cfgr().modify(|w| {
w.set_pllmul(Pllmul::from_bits(pllmul_bits));
w.set_pllsrc(Pllsrc::from_bits(config.hse.is_some() as u8));
});
RCC.cr().modify(|w| w.set_pllon(true));
while !RCC.cr().read().pllrdy() {}
}
RCC.cfgr().modify(|w| {
w.set_adcpre(Adcpre::from_bits(apre_bits));
w.set_ppre2(Ppre::from_bits(ppre2_bits));
w.set_ppre1(Ppre::from_bits(ppre1_bits));
w.set_hpre(Hpre::from_bits(hpre_bits));
#[cfg(not(rcc_f100))]
w.set_usbpre(Usbpre::from_bits(usbpre as u8));
w.set_sw(if pllmul_bits.is_some() {
Sw::PLL1_P
} else if config.hse.is_some() {
Sw::HSE
} else {
Sw::HSI
});
});
let rtc = config.ls.init();
set_freqs(Clocks {
sys: Hertz(real_sysclk),
pclk1: Hertz(pclk1),
pclk2: Hertz(pclk2),
pclk1_tim: Hertz(pclk1 * timer_mul1),
pclk2_tim: Hertz(pclk2 * timer_mul2),
hclk1: Hertz(hclk),
adc: Some(Hertz(adcclk)),
rtc,
});
}