158 lines
4 KiB
Rust
158 lines
4 KiB
Rust
#![macro_use]
|
|
|
|
use core::future::Future;
|
|
use core::task::Poll;
|
|
use defmt::*;
|
|
use embassy::traits;
|
|
use embassy::util::{AtomicWaker, Unborrow};
|
|
use embassy_extras::unborrow;
|
|
use futures::future::poll_fn;
|
|
use rand_core::{CryptoRng, RngCore};
|
|
|
|
use crate::interrupt;
|
|
use crate::pac;
|
|
|
|
static RNG_WAKER: AtomicWaker = AtomicWaker::new();
|
|
|
|
#[interrupt]
|
|
unsafe fn RNG() {
|
|
let bits = crate::pac::RNG.sr().read();
|
|
if bits.drdy() || bits.seis() || bits.ceis() {
|
|
crate::pac::RNG.cr().write(|reg| reg.set_ie(false));
|
|
RNG_WAKER.wake();
|
|
}
|
|
}
|
|
|
|
pub struct Random<T: Instance> {
|
|
inner: T,
|
|
}
|
|
|
|
impl<T: Instance> Random<T> {
|
|
pub fn new(inner: impl Unborrow<Target = T>) -> Self {
|
|
unborrow!(inner);
|
|
let mut random = Self { inner };
|
|
random.reset();
|
|
random
|
|
}
|
|
|
|
pub fn reset(&mut self) {
|
|
unsafe {
|
|
T::regs().cr().modify(|reg| {
|
|
reg.set_rngen(true);
|
|
reg.set_ie(true);
|
|
});
|
|
T::regs().sr().modify(|reg| {
|
|
reg.set_seis(false);
|
|
reg.set_ceis(false);
|
|
});
|
|
}
|
|
// Reference manual says to discard the first.
|
|
let _ = self.next_u32();
|
|
}
|
|
}
|
|
|
|
impl<T: Instance> RngCore for Random<T> {
|
|
fn next_u32(&mut self) -> u32 {
|
|
loop {
|
|
let bits = unsafe { T::regs().sr().read() };
|
|
if bits.drdy() {
|
|
return unsafe { T::regs().dr().read() };
|
|
}
|
|
}
|
|
}
|
|
|
|
fn next_u64(&mut self) -> u64 {
|
|
let mut rand = self.next_u32() as u64;
|
|
rand |= (self.next_u32() as u64) << 32;
|
|
rand
|
|
}
|
|
|
|
fn fill_bytes(&mut self, dest: &mut [u8]) {
|
|
for chunk in dest.chunks_mut(4) {
|
|
let rand = self.next_u32();
|
|
for (slot, num) in chunk.iter_mut().zip(rand.to_be_bytes().iter()) {
|
|
*slot = *num
|
|
}
|
|
}
|
|
}
|
|
|
|
fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), rand_core::Error> {
|
|
self.fill_bytes(dest);
|
|
Ok(())
|
|
}
|
|
}
|
|
|
|
impl<T: Instance> CryptoRng for Random<T> {}
|
|
|
|
pub enum Error {
|
|
SeedError,
|
|
ClockError,
|
|
}
|
|
|
|
impl<T: Instance> traits::rng::Rng for Random<T> {
|
|
type Error = Error;
|
|
#[rustfmt::skip]
|
|
type RngFuture<'a> where Self: 'a = impl Future<Output=Result<(), Self::Error>>;
|
|
|
|
fn fill_bytes<'a>(&'a mut self, dest: &'a mut [u8]) -> Self::RngFuture<'a> {
|
|
unsafe {
|
|
T::regs().cr().modify(|reg| {
|
|
reg.set_rngen(true);
|
|
});
|
|
}
|
|
async move {
|
|
for chunk in dest.chunks_mut(4) {
|
|
poll_fn(|cx| {
|
|
RNG_WAKER.register(cx.waker());
|
|
unsafe {
|
|
T::regs().cr().modify(|reg| {
|
|
reg.set_ie(true);
|
|
});
|
|
}
|
|
|
|
let bits = unsafe { T::regs().sr().read() };
|
|
|
|
if bits.drdy() {
|
|
Poll::Ready(Ok(()))
|
|
} else if bits.seis() {
|
|
self.reset();
|
|
Poll::Ready(Err(Error::SeedError))
|
|
} else if bits.ceis() {
|
|
self.reset();
|
|
Poll::Ready(Err(Error::ClockError))
|
|
} else {
|
|
Poll::Pending
|
|
}
|
|
})
|
|
.await?;
|
|
let random_bytes = unsafe { T::regs().dr().read() }.to_be_bytes();
|
|
for (dest, src) in chunk.iter_mut().zip(random_bytes.iter()) {
|
|
*dest = *src
|
|
}
|
|
}
|
|
Ok(())
|
|
}
|
|
}
|
|
}
|
|
|
|
pub(crate) mod sealed {
|
|
use super::*;
|
|
|
|
pub trait Instance {
|
|
fn regs() -> pac::rng::Rng;
|
|
}
|
|
}
|
|
|
|
pub trait Instance: sealed::Instance {}
|
|
|
|
macro_rules! impl_rng {
|
|
($inst:ident) => {
|
|
impl crate::rng::sealed::Instance for peripherals::RNG {
|
|
fn regs() -> crate::pac::chip::rng::Rng {
|
|
crate::pac::RNG
|
|
}
|
|
}
|
|
|
|
impl crate::rng::Instance for peripherals::RNG {}
|
|
};
|
|
}
|