From d18a919ab9cfa1c07d339dd885d8268ab0abb7e6 Mon Sep 17 00:00:00 2001
From: Dario Nieuwenhuis <dirbaio@dirbaio.net>
Date: Mon, 27 May 2024 00:11:13 +0200
Subject: [PATCH] rp: wait until read matches for PSM accesses.
---
embassy-rp/src/lib.rs | 25 +++++++++++++++++++++----
1 file changed, 21 insertions(+), 4 deletions(-)
diff --git a/embassy-rp/src/lib.rs b/embassy-rp/src/lib.rs
index 4602e66f4..507d42280 100644
--- a/embassy-rp/src/lib.rs
+++ b/embassy-rp/src/lib.rs
@@ -383,25 +383,29 @@ unsafe fn pre_init() {
//
// The PSM order is SIO -> PROC0 -> PROC1.
// So, we have to force-on PROC0 to prevent it from getting reset when resetting SIO.
- pac::PSM.frce_on().write(|w| {
+ pac::PSM.frce_on().write_and_wait(|w| {
w.set_proc0(true);
});
// Then reset SIO and PROC1.
- pac::PSM.frce_off().write(|w| {
+ pac::PSM.frce_off().write_and_wait(|w| {
w.set_sio(true);
w.set_proc1(true);
});
// clear force_off first, force_on second. The other way around would reset PROC0.
- pac::PSM.frce_off().write(|_| {});
- pac::PSM.frce_on().write(|_| {});
+ pac::PSM.frce_off().write_and_wait(|_| {});
+ pac::PSM.frce_on().write_and_wait(|_| {});
}
/// Extension trait for PAC regs, adding atomic xor/bitset/bitclear writes.
+#[allow(unused)]
trait RegExt<T: Copy> {
#[allow(unused)]
fn write_xor<R>(&self, f: impl FnOnce(&mut T) -> R) -> R;
fn write_set<R>(&self, f: impl FnOnce(&mut T) -> R) -> R;
fn write_clear<R>(&self, f: impl FnOnce(&mut T) -> R) -> R;
+ fn write_and_wait<R>(&self, f: impl FnOnce(&mut T) -> R) -> R
+ where
+ T: PartialEq;
}
impl<T: Default + Copy, A: pac::common::Write> RegExt<T> for pac::common::Reg<T, A> {
@@ -434,4 +438,17 @@ impl<T: Default + Copy, A: pac::common::Write> RegExt<T> for pac::common::Reg<T,
}
res
}
+
+ fn write_and_wait<R>(&self, f: impl FnOnce(&mut T) -> R) -> R
+ where
+ T: PartialEq,
+ {
+ let mut val = Default::default();
+ let res = f(&mut val);
+ unsafe {
+ self.as_ptr().write_volatile(val);
+ while self.as_ptr().read_volatile() != val {}
+ }
+ res
+ }
}