embassy/embassy-stm32/src/rcc/f4.rs

514 lines
14 KiB
Rust

use core::marker::PhantomData;
use embassy_hal_common::into_ref;
use stm32_metapac::rcc::vals::{Mco1, Mco2, Mcopre};
use super::sealed::RccPeripheral;
use crate::gpio::sealed::AFType;
use crate::gpio::Speed;
use crate::pac::rcc::vals::{Hpre, Ppre, Sw};
use crate::pac::{FLASH, PWR, RCC};
use crate::rcc::{set_freqs, Clocks};
use crate::time::Hertz;
use crate::{peripherals, Peripheral};
/// HSI speed
pub const HSI_FREQ: Hertz = Hertz(16_000_000);
/// LSI speed
pub const LSI_FREQ: Hertz = Hertz(32_000);
/// Clocks configuration
#[non_exhaustive]
#[derive(Default)]
pub struct Config {
pub hse: Option<Hertz>,
pub bypass_hse: bool,
pub hclk: Option<Hertz>,
pub sys_ck: Option<Hertz>,
pub pclk1: Option<Hertz>,
pub pclk2: Option<Hertz>,
#[cfg(not(any(stm32f410, stm32f411, stm32f412, stm32f413, stm32f423, stm32f446)))]
pub plli2s: Option<Hertz>,
pub pll48: bool,
}
#[cfg(stm32f410)]
fn setup_i2s_pll(_vco_in: u32, _plli2s: Option<u32>) -> Option<u32> {
None
}
// Not currently implemented, but will be in the future
#[cfg(any(stm32f411, stm32f412, stm32f413, stm32f423, stm32f446))]
fn setup_i2s_pll(_vco_in: u32, _plli2s: Option<u32>) -> Option<u32> {
None
}
#[cfg(not(any(stm32f410, stm32f411, stm32f412, stm32f413, stm32f423, stm32f446)))]
fn setup_i2s_pll(vco_in: u32, plli2s: Option<u32>) -> Option<u32> {
let min_div = 2;
let max_div = 7;
let target = match plli2s {
Some(target) => target,
None => return None,
};
// We loop through the possible divider values to find the best configuration. Looping
// through all possible "N" values would result in more iterations.
let (n, outdiv, output, _error) = (min_div..=max_div)
.filter_map(|outdiv| {
let target_vco_out = match target.checked_mul(outdiv) {
Some(x) => x,
None => return None,
};
let n = (target_vco_out + (vco_in >> 1)) / vco_in;
let vco_out = vco_in * n;
if !(100_000_000..=432_000_000).contains(&vco_out) {
return None;
}
let output = vco_out / outdiv;
let error = (output as i32 - target as i32).unsigned_abs();
Some((n, outdiv, output, error))
})
.min_by_key(|(_, _, _, error)| *error)?;
RCC.plli2scfgr().modify(|w| {
w.set_plli2sn(n as u16);
w.set_plli2sr(outdiv as u8);
});
Some(output)
}
fn setup_pll(pllsrcclk: u32, use_hse: bool, pllsysclk: Option<u32>, plli2s: Option<u32>, pll48clk: bool) -> PllResults {
use crate::pac::rcc::vals::{Pllp, Pllsrc};
let sysclk = pllsysclk.unwrap_or(pllsrcclk);
if pllsysclk.is_none() && !pll48clk {
RCC.pllcfgr().modify(|w| w.set_pllsrc(Pllsrc::from_bits(use_hse as u8)));
return PllResults {
use_pll: false,
pllsysclk: None,
pll48clk: None,
plli2sclk: None,
};
}
// Input divisor from PLL source clock, must result to frequency in
// the range from 1 to 2 MHz
let pllm_min = (pllsrcclk + 1_999_999) / 2_000_000;
let pllm_max = pllsrcclk / 1_000_000;
// Sysclk output divisor must be one of 2, 4, 6 or 8
let sysclk_div = core::cmp::min(8, (432_000_000 / sysclk) & !1);
let target_freq = if pll48clk { 48_000_000 } else { sysclk * sysclk_div };
// Find the lowest pllm value that minimize the difference between
// target frequency and the real vco_out frequency.
let pllm = unwrap!((pllm_min..=pllm_max).min_by_key(|pllm| {
let vco_in = pllsrcclk / pllm;
let plln = target_freq / vco_in;
target_freq - vco_in * plln
}));
let vco_in = pllsrcclk / pllm;
assert!((1_000_000..=2_000_000).contains(&vco_in));
// Main scaler, must result in >= 100MHz (>= 192MHz for F401)
// and <= 432MHz, min 50, max 432
let plln = if pll48clk {
// try the different valid pllq according to the valid
// main scaller values, and take the best
let pllq = unwrap!((4..=9).min_by_key(|pllq| {
let plln = 48_000_000 * pllq / vco_in;
let pll48_diff = 48_000_000 - vco_in * plln / pllq;
let sysclk_diff = (sysclk as i32 - (vco_in * plln / sysclk_div) as i32).abs();
(pll48_diff, sysclk_diff)
}));
48_000_000 * pllq / vco_in
} else {
sysclk * sysclk_div / vco_in
};
let pllp = (sysclk_div / 2) - 1;
let pllq = (vco_in * plln + 47_999_999) / 48_000_000;
let real_pll48clk = vco_in * plln / pllq;
RCC.pllcfgr().modify(|w| {
w.set_pllm(pllm as u8);
w.set_plln(plln as u16);
w.set_pllp(Pllp::from_bits(pllp as u8));
w.set_pllq(pllq as u8);
w.set_pllsrc(Pllsrc::from_bits(use_hse as u8));
});
let real_pllsysclk = vco_in * plln / sysclk_div;
PllResults {
use_pll: true,
pllsysclk: Some(real_pllsysclk),
pll48clk: if pll48clk { Some(real_pll48clk) } else { None },
plli2sclk: setup_i2s_pll(vco_in, plli2s),
}
}
pub enum McoClock {
DIV1,
DIV2,
DIV3,
DIV4,
DIV5,
}
impl McoClock {
fn into_raw(&self) -> Mcopre {
match self {
McoClock::DIV1 => Mcopre::DIV1,
McoClock::DIV2 => Mcopre::DIV2,
McoClock::DIV3 => Mcopre::DIV3,
McoClock::DIV4 => Mcopre::DIV4,
McoClock::DIV5 => Mcopre::DIV5,
}
}
}
#[derive(Copy, Clone)]
pub enum Mco1Source {
Hsi,
Lse,
Hse,
Pll,
}
impl Default for Mco1Source {
fn default() -> Self {
Self::Hsi
}
}
pub trait McoSource {
type Raw;
fn into_raw(&self) -> Self::Raw;
}
impl McoSource for Mco1Source {
type Raw = Mco1;
fn into_raw(&self) -> Self::Raw {
match self {
Mco1Source::Hsi => Mco1::HSI,
Mco1Source::Lse => Mco1::LSE,
Mco1Source::Hse => Mco1::HSE,
Mco1Source::Pll => Mco1::PLL,
}
}
}
#[derive(Copy, Clone)]
pub enum Mco2Source {
SysClk,
Plli2s,
Hse,
Pll,
}
impl Default for Mco2Source {
fn default() -> Self {
Self::SysClk
}
}
impl McoSource for Mco2Source {
type Raw = Mco2;
fn into_raw(&self) -> Self::Raw {
match self {
Mco2Source::SysClk => Mco2::SYSCLK,
Mco2Source::Plli2s => Mco2::PLLI2S,
Mco2Source::Hse => Mco2::HSE,
Mco2Source::Pll => Mco2::PLL,
}
}
}
pub(crate) mod sealed {
use stm32_metapac::rcc::vals::Mcopre;
pub trait McoInstance {
type Source;
unsafe fn apply_clock_settings(source: Self::Source, prescaler: Mcopre);
}
}
pub trait McoInstance: sealed::McoInstance + 'static {}
pin_trait!(McoPin, McoInstance);
impl sealed::McoInstance for peripherals::MCO1 {
type Source = Mco1;
unsafe fn apply_clock_settings(source: Self::Source, prescaler: Mcopre) {
RCC.cfgr().modify(|w| {
w.set_mco1(source);
w.set_mco1pre(prescaler);
});
match source {
Mco1::PLL => {
RCC.cr().modify(|w| w.set_pllon(true));
while !RCC.cr().read().pllrdy() {}
}
Mco1::HSI => {
RCC.cr().modify(|w| w.set_hsion(true));
while !RCC.cr().read().hsirdy() {}
}
_ => {}
}
}
}
impl McoInstance for peripherals::MCO1 {}
impl sealed::McoInstance for peripherals::MCO2 {
type Source = Mco2;
unsafe fn apply_clock_settings(source: Self::Source, prescaler: Mcopre) {
RCC.cfgr().modify(|w| {
w.set_mco2(source);
w.set_mco2pre(prescaler);
});
match source {
Mco2::PLL => {
RCC.cr().modify(|w| w.set_pllon(true));
while !RCC.cr().read().pllrdy() {}
}
#[cfg(not(stm32f410))]
Mco2::PLLI2S => {
RCC.cr().modify(|w| w.set_plli2son(true));
while !RCC.cr().read().plli2srdy() {}
}
_ => {}
}
}
}
impl McoInstance for peripherals::MCO2 {}
pub struct Mco<'d, T: McoInstance> {
phantom: PhantomData<&'d mut T>,
}
impl<'d, T: McoInstance> Mco<'d, T> {
pub fn new(
_peri: impl Peripheral<P = T> + 'd,
pin: impl Peripheral<P = impl McoPin<T>> + 'd,
source: impl McoSource<Raw = T::Source>,
prescaler: McoClock,
) -> Self {
into_ref!(pin);
critical_section::with(|_| unsafe {
T::apply_clock_settings(source.into_raw(), prescaler.into_raw());
pin.set_as_af(pin.af_num(), AFType::OutputPushPull);
pin.set_speed(Speed::VeryHigh);
});
Self { phantom: PhantomData }
}
}
fn flash_setup(sysclk: u32) {
use crate::pac::flash::vals::Latency;
// Be conservative with voltage ranges
const FLASH_LATENCY_STEP: u32 = 30_000_000;
critical_section::with(|_| {
FLASH
.acr()
.modify(|w| w.set_latency(Latency::from_bits(((sysclk - 1) / FLASH_LATENCY_STEP) as u8)));
});
}
pub(crate) unsafe fn init(config: Config) {
crate::peripherals::PWR::enable();
let pllsrcclk = config.hse.map(|hse| hse.0).unwrap_or(HSI_FREQ.0);
let sysclk = config.sys_ck.map(|sys| sys.0).unwrap_or(pllsrcclk);
let sysclk_on_pll = sysclk != pllsrcclk;
let plls = setup_pll(
pllsrcclk,
config.hse.is_some(),
if sysclk_on_pll { Some(sysclk) } else { None },
#[cfg(not(any(stm32f410, stm32f411, stm32f412, stm32f413, stm32f423, stm32f446)))]
config.plli2s.map(|i2s| i2s.0),
#[cfg(any(stm32f410, stm32f411, stm32f412, stm32f413, stm32f423, stm32f446))]
None,
config.pll48,
);
if config.pll48 {
let freq = unwrap!(plls.pll48clk);
assert!((max::PLL_48_CLK as i32 - freq as i32).abs() <= max::PLL_48_TOLERANCE as i32);
}
let sysclk = if sysclk_on_pll { unwrap!(plls.pllsysclk) } else { sysclk };
// AHB prescaler
let hclk = config.hclk.map(|h| h.0).unwrap_or(sysclk);
let (hpre_bits, hpre_div) = match (sysclk + hclk - 1) / hclk {
0 => unreachable!(),
1 => (Hpre::DIV1, 1),
2 => (Hpre::DIV2, 2),
3..=5 => (Hpre::DIV4, 4),
6..=11 => (Hpre::DIV8, 8),
12..=39 => (Hpre::DIV16, 16),
40..=95 => (Hpre::DIV64, 64),
96..=191 => (Hpre::DIV128, 128),
192..=383 => (Hpre::DIV256, 256),
_ => (Hpre::DIV512, 512),
};
// Calculate real AHB clock
let hclk = sysclk / hpre_div;
let pclk1 = config
.pclk1
.map(|p| p.0)
.unwrap_or_else(|| core::cmp::min(max::PCLK1_MAX, hclk));
let (ppre1_bits, ppre1) = match (hclk + pclk1 - 1) / pclk1 {
0 => unreachable!(),
1 => (0b000, 1),
2 => (0b100, 2),
3..=5 => (0b101, 4),
6..=11 => (0b110, 8),
_ => (0b111, 16),
};
let timer_mul1 = if ppre1 == 1 { 1 } else { 2 };
// Calculate real APB1 clock
let pclk1 = hclk / ppre1;
assert!(pclk1 <= max::PCLK1_MAX);
let pclk2 = config
.pclk2
.map(|p| p.0)
.unwrap_or_else(|| core::cmp::min(max::PCLK2_MAX, hclk));
let (ppre2_bits, ppre2) = match (hclk + pclk2 - 1) / pclk2 {
0 => unreachable!(),
1 => (0b000, 1),
2 => (0b100, 2),
3..=5 => (0b101, 4),
6..=11 => (0b110, 8),
_ => (0b111, 16),
};
let timer_mul2 = if ppre2 == 1 { 1 } else { 2 };
// Calculate real APB2 clock
let pclk2 = hclk / ppre2;
assert!(pclk2 <= max::PCLK2_MAX);
flash_setup(sysclk);
if config.hse.is_some() {
RCC.cr().modify(|w| {
w.set_hsebyp(config.bypass_hse);
w.set_hseon(true);
});
while !RCC.cr().read().hserdy() {}
}
if plls.use_pll {
RCC.cr().modify(|w| w.set_pllon(true));
if hclk > max::HCLK_OVERDRIVE_FREQUENCY {
PWR.cr1().modify(|w| w.set_oden(true));
while !PWR.csr1().read().odrdy() {}
PWR.cr1().modify(|w| w.set_odswen(true));
while !PWR.csr1().read().odswrdy() {}
}
while !RCC.cr().read().pllrdy() {}
}
#[cfg(not(stm32f410))]
if plls.plli2sclk.is_some() {
RCC.cr().modify(|w| w.set_plli2son(true));
while !RCC.cr().read().plli2srdy() {}
}
RCC.cfgr().modify(|w| {
w.set_ppre2(Ppre::from_bits(ppre2_bits));
w.set_ppre1(Ppre::from_bits(ppre1_bits));
w.set_hpre(hpre_bits);
});
// Wait for the new prescalers to kick in
// "The clocks are divided with the new prescaler factor from 1 to 16 AHB cycles after write"
cortex_m::asm::delay(16);
RCC.cfgr().modify(|w| {
w.set_sw(if sysclk_on_pll {
Sw::PLL
} else if config.hse.is_some() {
Sw::HSE
} else {
Sw::HSI
})
});
set_freqs(Clocks {
sys: Hertz(sysclk),
apb1: Hertz(pclk1),
apb2: Hertz(pclk2),
apb1_tim: Hertz(pclk1 * timer_mul1),
apb2_tim: Hertz(pclk2 * timer_mul2),
ahb1: Hertz(hclk),
ahb2: Hertz(hclk),
ahb3: Hertz(hclk),
pll48: plls.pll48clk.map(Hertz),
#[cfg(not(stm32f410))]
plli2s: plls.plli2sclk.map(Hertz),
#[cfg(any(stm32f427, stm32f429, stm32f437, stm32f439, stm32f446, stm32f469, stm32f479))]
pllsai: None,
});
}
struct PllResults {
use_pll: bool,
pllsysclk: Option<u32>,
pll48clk: Option<u32>,
#[allow(dead_code)]
plli2sclk: Option<u32>,
}
mod max {
#[cfg(stm32f401)]
pub(crate) const SYSCLK_MAX: u32 = 84_000_000;
#[cfg(any(stm32f405, stm32f407, stm32f415, stm32f417,))]
pub(crate) const SYSCLK_MAX: u32 = 168_000_000;
#[cfg(any(stm32f410, stm32f411, stm32f412, stm32f413, stm32f423,))]
pub(crate) const SYSCLK_MAX: u32 = 100_000_000;
#[cfg(any(stm32f427, stm32f429, stm32f437, stm32f439, stm32f446, stm32f469, stm32f479,))]
pub(crate) const SYSCLK_MAX: u32 = 180_000_000;
pub(crate) const HCLK_OVERDRIVE_FREQUENCY: u32 = 168_000_000;
pub(crate) const PCLK1_MAX: u32 = PCLK2_MAX / 2;
#[cfg(any(stm32f401, stm32f410, stm32f411, stm32f412, stm32f413, stm32f423,))]
pub(crate) const PCLK2_MAX: u32 = SYSCLK_MAX;
#[cfg(not(any(stm32f401, stm32f410, stm32f411, stm32f412, stm32f413, stm32f423,)))]
pub(crate) const PCLK2_MAX: u32 = SYSCLK_MAX / 2;
pub(crate) const PLL_48_CLK: u32 = 48_000_000;
pub(crate) const PLL_48_TOLERANCE: u32 = 120_000;
}