From 556942a6bf0933921f33bfcb0155fbabf33b59c6 Mon Sep 17 00:00:00 2001
From: xoviat <xoviat@users.noreply.github.com>
Date: Sat, 20 Mar 2021 23:51:24 -0500
Subject: [PATCH] stm32f4: implement idle on serial

---
 embassy-stm32f4/Cargo.toml    |  1 +
 embassy-stm32f4/src/serial.rs | 42 +++++++++++++++++++++++++----------
 2 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/embassy-stm32f4/Cargo.toml b/embassy-stm32f4/Cargo.toml
index ae3273d6..c132d7c9 100644
--- a/embassy-stm32f4/Cargo.toml
+++ b/embassy-stm32f4/Cargo.toml
@@ -36,6 +36,7 @@ defmt = { version = "0.2.0", optional = true }
 log = { version = "0.4.11", optional = true }
 cortex-m-rt = "0.6.13"
 cortex-m = "0.7.1"
+futures = { version = "0.3.5", default-features = false, features = ["async-await"] }
 embedded-hal    = { version = "0.2.4" }
 embedded-dma    = { version = "0.1.2" }
 stm32f4xx-hal  = { version = "0.8.3", features = ["rt", "can"], git = "https://github.com/stm32-rs/stm32f4xx-hal.git"}
diff --git a/embassy-stm32f4/src/serial.rs b/embassy-stm32f4/src/serial.rs
index 381e0f5e..bed89288 100644
--- a/embassy-stm32f4/src/serial.rs
+++ b/embassy-stm32f4/src/serial.rs
@@ -7,6 +7,8 @@
 use core::future::Future;
 use core::marker::PhantomData;
 
+use futures::{select_biased, FutureExt};
+
 use embassy::interrupt::Interrupt;
 use embassy::traits::uart::{Error, Uart};
 use embassy::util::InterruptFuture;
@@ -19,7 +21,7 @@ use crate::hal::{
     rcc::Clocks,
     serial,
     serial::config::{Config as SerialConfig, DmaConfig as SerialDmaConfig},
-    serial::{Event as SerialEvent, Pins, Serial as HalSerial},
+    serial::{Event as SerialEvent, Pins},
 };
 use crate::interrupt;
 use crate::pac;
@@ -29,14 +31,14 @@ pub struct Serial<
     USART: PeriAddress<MemSize = u8> + WithInterrupt,
     TSTREAM: Stream + WithInterrupt,
     RSTREAM: Stream + WithInterrupt,
-    CHANNEL: dma::traits::Channel,
+    CHANNEL: Channel,
 > {
     tx_stream: Option<TSTREAM>,
     rx_stream: Option<RSTREAM>,
     usart: Option<USART>,
     tx_int: TSTREAM::Interrupt,
     rx_int: RSTREAM::Interrupt,
-    _usart_int: USART::Interrupt,
+    usart_int: USART::Interrupt,
     channel: PhantomData<CHANNEL>,
 }
 
@@ -68,12 +70,10 @@ where
         PINS: Pins<USART>,
     {
         config.dma = SerialDmaConfig::TxRx;
-        let mut serial = HalSerial::new(usart, pins, config, clocks).unwrap();
 
-        serial.listen(SerialEvent::Idle);
-        //        serial.listen(SerialEvent::Txe);
-
-        let (usart, _) = serial.release();
+        let (usart, _) = serial::Serial::new(usart, pins, config, clocks)
+            .unwrap()
+            .release();
 
         let (tx_stream, rx_stream) = streams;
 
@@ -83,8 +83,8 @@ where
             usart: Some(usart),
             tx_int: tx_int,
             rx_int: rx_int,
-            _usart_int: usart_int,
-            channel: core::marker::PhantomData,
+            usart_int: usart_int,
+            channel: PhantomData,
         }
     }
 }
@@ -127,10 +127,10 @@ where
             let fut = InterruptFuture::new(&mut self.tx_int);
 
             tx_transfer.start(|_usart| {});
-
             fut.await;
 
             let (tx_stream, usart, _buf, _) = tx_transfer.free();
+
             self.tx_stream.replace(tx_stream);
             self.usart.replace(usart);
 
@@ -151,6 +151,15 @@ where
         let usart = self.usart.take().unwrap();
 
         async move {
+            unsafe {
+                /*  __HAL_UART_ENABLE_IT(&uart->UartHandle, UART_IT_IDLE); */
+                (*USART::ptr()).cr1.modify(|_, w| w.idleie().set_bit());
+
+                /* __HAL_UART_CLEAR_IDLEFLAG(&uart->UartHandle); */
+                (*USART::ptr()).sr.read();
+                (*USART::ptr()).dr.read();
+            };
+
             let mut rx_transfer = Transfer::init(
                 rx_stream,
                 usart,
@@ -163,11 +172,20 @@ where
             );
 
             let fut = InterruptFuture::new(&mut self.rx_int);
+            let fut_idle = InterruptFuture::new(&mut self.usart_int);
 
             rx_transfer.start(|_usart| {});
-            fut.await;
+
+            select_biased! {
+                () = fut.fuse() => {},
+                () = fut_idle.fuse() => {},
+            }
 
             let (rx_stream, usart, _, _) = rx_transfer.free();
+
+            unsafe {
+                (*USART::ptr()).cr1.modify(|_, w| w.idleie().clear_bit());
+            }
             self.rx_stream.replace(rx_stream);
             self.usart.replace(usart);