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add RNG conditioning

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Jan Christoph Bernack 2023-07-01 03:15:39 +02:00 committed by Dario Nieuwenhuis
parent 39c1cc9f00
commit b65406791a
1 changed files with 33 additions and 0 deletions
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33
embassy-stm32/src/rng.rs
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@ -31,6 +31,7 @@ impl<'d, T: Instance> Rng<'d, T> {
random random
} }
#[cfg(rng_v1)]
pub fn reset(&mut self) { pub fn reset(&mut self) {
// rng_v2 locks up on seed error, needs reset // rng_v2 locks up on seed error, needs reset
#[cfg(rng_v2)] #[cfg(rng_v2)]
@ -49,6 +50,38 @@ impl<'d, T: Instance> Rng<'d, T> {
let _ = self.next_u32(); let _ = self.next_u32();
} }
#[cfg(not(rng_v1))]
pub fn reset(&mut self) {
T::regs().cr().modify(|reg| {
reg.set_rngen(false);
reg.set_condrst(true);
// set RNG config "A" according to reference manual
// this has to be written within the same write access as setting the CONDRST bit
reg.set_nistc(pac::rng::vals::Nistc::DEFAULT);
reg.set_rng_config1(pac::rng::vals::RngConfig1::CONFIGA);
reg.set_rng_config2(pac::rng::vals::RngConfig2::CONFIGA_B);
reg.set_rng_config3(pac::rng::vals::RngConfig3::CONFIGA);
reg.set_clkdiv(pac::rng::vals::Clkdiv::NODIV);
});
// wait for CONDRST to be set
while !T::regs().cr().read().condrst() {}
// magic number must be written immediately before every read or write access to HTCR
T::regs().htcr().write(|w| w.set_htcfg(pac::rng::vals::Htcfg::MAGIC));
// write recommended value according to reference manual
// note: HTCR can only be written during conditioning
T::regs()
.htcr()
.write(|w| w.set_htcfg(pac::rng::vals::Htcfg::RECOMMENDED));
// finish conditioning
T::regs().cr().modify(|reg| {
reg.set_rngen(true);
reg.set_condrst(false);
reg.set_ie(true);
});
// wait for CONDRST to be reset
while T::regs().cr().read().condrst() {}
}
pub async fn async_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error> { pub async fn async_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error> {
T::regs().cr().modify(|reg| { T::regs().cr().modify(|reg| {
reg.set_rngen(true); reg.set_rngen(true);