Attempt to add read_single_word

imxrt-rs · Dec 15, 2023 · 64ff0c9 · 64ff0c9
1 parent 88a5d60
commit 64ff0c9
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Showing 2 changed files with 49 additions and 9 deletions.
diff --git a/src/common/lpspi/read_part.rs b/src/common/lpspi/read_part.rs
@@ -1,11 +1,13 @@
+use core::num::NonZeroUsize;
+
 use super::{
     ral,
     transfer_actions::{ByteOrder, ReadAction},
     LpspiReadPart,
 };
 
 impl<const N: u8> LpspiReadPart<'_, N> {
-    fn fifo_read_data_available(&self) -> bool {
+    fn fifo_read_data_available(&mut self) -> bool {
         ral::read_reg!(
             ral::lpspi,
             self.data.lpspi.instance(),
@@ -14,7 +16,7 @@ impl<const N: u8> LpspiReadPart<'_, N> {
         )
     }
 
-    async fn wait_for_read_watermark(&self, watermark: u32) {
+    async fn wait_for_read_watermark(&mut self, watermark: u32) {
         self.data
             .lpspi
             .wait_for_rx_watermark(watermark)
@@ -44,14 +46,52 @@ impl<const N: u8> LpspiReadPart<'_, N> {
     ) {
         for action in actions {
             if action.len.get() < 4 {
-                todo!();
-                // self.read_single_word(action.buf, byteorder, action.len)
-                //     .await
+                self.read_single_word(action.buf, byteorder, action.len)
+                    .await
             } else {
                 todo!();
                 // self.read_u32_stream(action.buf, byteorder, action.len)
                 //     .await;
             }
         }
     }
+
+    async fn rx_fifo_read_data(&mut self, num_leftover: usize) -> u32 {
+        self.wait_for_read_data_available(num_leftover).await;
+        ral::read_reg!(ral::lpspi, self.data.lpspi.instance(), RDR)
+    }
+
+    pub async unsafe fn read_single_word(
+        &mut self,
+        data: *mut u8,
+        byteorder: ByteOrder,
+        len: NonZeroUsize,
+    ) {
+        assert!(len.get() < 4);
+
+        let reverse_bytes = match byteorder {
+            ByteOrder::Normal => false,
+            ByteOrder::WordReversed => true,
+            ByteOrder::HalfWordReversed => true,
+        };
+
+        log::info!("Receiving ...");
+        let value = self.rx_fifo_read_data(1).await;
+        log::info!("Read: 0x{:02x}", value);
+        let rx_buffer = value.to_le_bytes();
+
+        let active_buffer = &rx_buffer[(4 - len.get())..];
+        if reverse_bytes {
+            active_buffer
+                .iter()
+                .rev()
+                .enumerate()
+                .for_each(|(pos, val)| data.add(pos).write(*val));
+        } else {
+            active_buffer
+                .iter()
+                .enumerate()
+                .for_each(|(pos, val)| data.add(pos).write(*val));
+        }
+    }
 }
diff --git a/src/common/lpspi/write_part.rs b/src/common/lpspi/write_part.rs
@@ -9,7 +9,7 @@ use super::{
 };
 
 impl<const N: u8> LpspiWritePart<'_, N> {
-    fn fifo_write_space_available(&self) -> bool {
+    fn fifo_write_space_available(&mut self) -> bool {
         ral::read_reg!(
             ral::lpspi,
             self.data.lpspi.instance(),
@@ -18,17 +18,17 @@ impl<const N: u8> LpspiWritePart<'_, N> {
         )
     }
 
-    async fn wait_for_write_watermark(&self) {
+    async fn wait_for_write_watermark(&mut self) {
         self.data.lpspi.wait_for_tx_watermark().await.unwrap();
     }
 
-    async fn wait_for_write_space_available(&self) {
+    async fn wait_for_write_space_available(&mut self) {
         if !self.fifo_write_space_available() {
             self.wait_for_write_watermark().await;
         }
     }
 
-    async fn tx_fifo_enqueue_data(&self, val: u32) {
+    async fn tx_fifo_enqueue_data(&mut self, val: u32) {
         self.wait_for_write_space_available().await;
         ral::write_reg!(ral::lpspi, self.data.lpspi.instance(), TDR, val);
     }