Merge #525

525: Applies the Uarte patch r=huntc a=huntc

Applies the Nordic workaround found in the `Uarte` for the nRF9160 and nRF5340 to the `BufferedUarte`.

Co-authored-by: huntc <[email protected]>

2 files changed, 56 insertions, 57 deletions

diff --git a/embassy-nrf/src/buffered_uarte.rs b/embassy-nrf/src/buffered_uarte.rs
index 5468f6c0b..9b0451c12 100644
--- a/embassy-nrf/src/buffered_uarte.rs
+++ b/embassy-nrf/src/buffered_uarte.rs
@@ -22,7 +22,7 @@ use crate::pac;
 use crate::ppi::{AnyConfigurableChannel, ConfigurableChannel, Event, Ppi, Task};
 use crate::timer::Instance as TimerInstance;
 use crate::timer::{Frequency, Timer};
-use crate::uarte::{Config, Instance as UarteInstance};
+use crate::uarte::{apply_workaround_for_enable_anomaly, Config, Instance as UarteInstance};
 
 // Re-export SVD variants to allow user to directly set values
 pub use pac::uarte0::{baudrate::BAUDRATE_A as Baudrate, config::PARITY_A as Parity};
@@ -132,6 +132,7 @@ impl<'d, U: UarteInstance, T: TimerInstance> BufferedUarte<'d, U, T> {
         irq.pend();
 
         // Enable UARTE instance
+        apply_workaround_for_enable_anomaly(&r);
         r.enable.write(|w| w.enable().enabled());
 
         // BAUDRATE register values are `baudrate * 2^32 / 16000000`
diff --git a/embassy-nrf/src/uarte.rs b/embassy-nrf/src/uarte.rs
index 60e69e032..72dcd41b2 100644
--- a/embassy-nrf/src/uarte.rs
+++ b/embassy-nrf/src/uarte.rs
@@ -116,7 +116,7 @@ impl<'d, T: Instance> Uarte<'d, T> {
         irq.enable();
 
         // Enable
-        Self::apply_workaround_for_enable_anomaly();
+        apply_workaround_for_enable_anomaly(&r);
         r.enable.write(|w| w.enable().enabled());
 
         Self {
@@ -124,61 +124,6 @@ impl<'d, T: Instance> Uarte<'d, T> {
         }
     }
 
-    #[cfg(not(any(feature = "_nrf9160", feature = "nrf5340")))]
-    fn apply_workaround_for_enable_anomaly() {
-        // Do nothing
-    }
-
-    #[cfg(any(feature = "_nrf9160", feature = "nrf5340"))]
-    fn apply_workaround_for_enable_anomaly() {
-        use core::ops::Deref;
-
-        let r = T::regs();
-
-        // Apply workaround for anomalies:
-        // - nRF9160 - anomaly 23
-        // - nRF5340 - anomaly 44
-        let rxenable_reg: *const u32 = ((r.deref() as *const _ as usize) + 0x564) as *const u32;
-        let txenable_reg: *const u32 = ((r.deref() as *const _ as usize) + 0x568) as *const u32;
-
-        // NB Safety: This is taken from Nordic's driver -
-        // https://github.com/NordicSemiconductor/nrfx/blob/master/drivers/src/nrfx_uarte.c#L197
-        if unsafe { core::ptr::read_volatile(txenable_reg) } == 1 {
-            r.tasks_stoptx.write(|w| unsafe { w.bits(1) });
-        }
-
-        // NB Safety: This is taken from Nordic's driver -
-        // https://github.com/NordicSemiconductor/nrfx/blob/master/drivers/src/nrfx_uarte.c#L197
-        if unsafe { core::ptr::read_volatile(rxenable_reg) } == 1 {
-            r.enable.write(|w| w.enable().enabled());
-            r.tasks_stoprx.write(|w| unsafe { w.bits(1) });
-
-            let mut workaround_succeded = false;
-            // The UARTE is able to receive up to four bytes after the STOPRX task has been triggered.
-            // On lowest supported baud rate (1200 baud), with parity bit and two stop bits configured
-            // (resulting in 12 bits per data byte sent), this may take up to 40 ms.
-            for _ in 0..40000 {
-                // NB Safety: This is taken from Nordic's driver -
-                // https://github.com/NordicSemiconductor/nrfx/blob/master/drivers/src/nrfx_uarte.c#L197
-                if unsafe { core::ptr::read_volatile(rxenable_reg) } == 0 {
-                    workaround_succeded = true;
-                    break;
-                } else {
-                    // Need to sleep for 1us here
-                }
-            }
-
-            if !workaround_succeded {
-                panic!("Failed to apply workaround for UART");
-            }
-
-            let errors = r.errorsrc.read().bits();
-            // NB Safety: safe to write back the bits we just read to clear them
-            r.errorsrc.write(|w| unsafe { w.bits(errors) });
-            r.enable.write(|w| w.enable().disabled());
-        }
-    }
-
     fn on_interrupt(_: *mut ()) {
         let r = T::regs();
         let s = T::state();
@@ -330,6 +275,59 @@ impl<'d, T: Instance> Write for Uarte<'d, T> {
     }
 }
 
+#[cfg(not(any(feature = "_nrf9160", feature = "nrf5340")))]
+pub(in crate) fn apply_workaround_for_enable_anomaly(_r: &crate::pac::uarte0::RegisterBlock) {
+    // Do nothing
+}
+
+#[cfg(any(feature = "_nrf9160", feature = "nrf5340"))]
+pub(in crate) fn apply_workaround_for_enable_anomaly(r: &crate::pac::uarte0::RegisterBlock) {
+    use core::ops::Deref;
+
+    // Apply workaround for anomalies:
+    // - nRF9160 - anomaly 23
+    // - nRF5340 - anomaly 44
+    let rxenable_reg: *const u32 = ((r.deref() as *const _ as usize) + 0x564) as *const u32;
+    let txenable_reg: *const u32 = ((r.deref() as *const _ as usize) + 0x568) as *const u32;
+
+    // NB Safety: This is taken from Nordic's driver -
+    // https://github.com/NordicSemiconductor/nrfx/blob/master/drivers/src/nrfx_uarte.c#L197
+    if unsafe { core::ptr::read_volatile(txenable_reg) } == 1 {
+        r.tasks_stoptx.write(|w| unsafe { w.bits(1) });
+    }
+
+    // NB Safety: This is taken from Nordic's driver -
+    // https://github.com/NordicSemiconductor/nrfx/blob/master/drivers/src/nrfx_uarte.c#L197
+    if unsafe { core::ptr::read_volatile(rxenable_reg) } == 1 {
+        r.enable.write(|w| w.enable().enabled());
+        r.tasks_stoprx.write(|w| unsafe { w.bits(1) });
+
+        let mut workaround_succeded = false;
+        // The UARTE is able to receive up to four bytes after the STOPRX task has been triggered.
+        // On lowest supported baud rate (1200 baud), with parity bit and two stop bits configured
+        // (resulting in 12 bits per data byte sent), this may take up to 40 ms.
+        for _ in 0..40000 {
+            // NB Safety: This is taken from Nordic's driver -
+            // https://github.com/NordicSemiconductor/nrfx/blob/master/drivers/src/nrfx_uarte.c#L197
+            if unsafe { core::ptr::read_volatile(rxenable_reg) } == 0 {
+                workaround_succeded = true;
+                break;
+            } else {
+                // Need to sleep for 1us here
+            }
+        }
+
+        if !workaround_succeded {
+            panic!("Failed to apply workaround for UART");
+        }
+
+        let errors = r.errorsrc.read().bits();
+        // NB Safety: safe to write back the bits we just read to clear them
+        r.errorsrc.write(|w| unsafe { w.bits(errors) });
+        r.enable.write(|w| w.enable().disabled());
+    }
+}
+
 /// Interface to an UARTE peripheral that uses an additional timer and two PPI channels,
 /// allowing it to implement the ReadUntilIdle trait.
 pub struct UarteWithIdle<'d, U: Instance, T: TimerInstance> {