Don't require &mut for tx-buffer

esp-hal/src/aes/mod.rs

@@ -387,7 +387,7 @@ pub mod dma {
         /// is 32736 bytes.
         pub fn process<'t, TXBUF, RXBUF>(
             &'t mut self,
-            words: &'t mut TXBUF,
+            words: &'t TXBUF,
             read_buffer: &'t mut RXBUF,
             mode: Mode,
             cipher_mode: CipherMode,

esp-hal/src/i2s.rs

@@ -295,7 +295,7 @@ where
     /// transfer
     fn write_dma<'t>(
         &'t mut self,
-        words: &'t mut TXBUF,
+        words: &'t TXBUF,
     ) -> Result<I2sWriteDmaTransfer<'t, 'd, T, CH>, Error>
     where
         TXBUF: ReadBuffer<Word = u8>;
@@ -304,7 +304,7 @@ where
     /// represents the in-progress DMA transfer
     fn write_dma_circular<'t>(
         &'t mut self,
-        words: &'t mut TXBUF,
+        words: &'t TXBUF,
     ) -> Result<I2sWriteDmaTransfer<'t, 'd, T, CH>, Error>
     where
         TXBUF: ReadBuffer<Word = u8>;
@@ -574,7 +574,7 @@ where
 
     fn start_tx_transfer<'t, TXBUF>(
         &'t mut self,
-        words: &'t mut TXBUF,
+        words: &'t TXBUF,
         circular: bool,
     ) -> Result<I2sWriteDmaTransfer<'t, 'd, T, CH>, Error>
     where
@@ -656,7 +656,7 @@ where
 {
     fn write_dma<'t>(
         &'t mut self,
-        words: &'t mut TXBUF,
+        words: &'t TXBUF,
     ) -> Result<I2sWriteDmaTransfer<'t, 'd, T, CH>, Error>
     where
         TXBUF: ReadBuffer<Word = u8>,
@@ -666,7 +666,7 @@ where
 
     fn write_dma_circular<'t>(
         &'t mut self,
-        words: &'t mut TXBUF,
+        words: &'t TXBUF,
     ) -> Result<I2sWriteDmaTransfer<'t, 'd, T, CH>, Error>
     where
         TXBUF: ReadBuffer<Word = u8>,

esp-hal/src/lcd_cam/lcd/i8080.rs

@@ -300,7 +300,7 @@ where
         &'t mut self,
         cmd: impl Into<Command<P::Word>>,
         dummy: u8,
-        data: &mut TXBUF,
+        data: &'t TXBUF,
     ) -> Result<Transfer<'t, 'd, TX, P>, DmaError>
     where
         TXBUF: ReadBuffer<Word = P::Word>,

esp-hal/src/parl_io.rs

@@ -1167,7 +1167,7 @@ where
     /// The maximum amount of data to be sent is 32736 bytes.
     pub fn write_dma<'t, TXBUF>(
         &'t mut self,
-        words: &'t mut TXBUF,
+        words: &'t TXBUF,
     ) -> Result<DmaTransfer<'t, 'd, CH, P, CP>, Error>
     where
         TXBUF: ReadBuffer<Word = u8>,

esp-hal/src/spi/master.rs

@@ -988,7 +988,7 @@ pub mod dma {
         #[cfg_attr(feature = "place-spi-driver-in-ram", ram)]
         pub fn dma_write<'t, TXBUF>(
             &'t mut self,
-            words: &'t mut TXBUF,
+            words: &'t TXBUF,
         ) -> Result<SpiDmaTransfer<'t, 'd, T, C, M>, super::Error>
         where
             TXBUF: ReadBuffer<Word = u8>,
@@ -1035,7 +1035,7 @@ pub mod dma {
         /// 32736 bytes.
         pub fn dma_transfer<'t, TXBUF, RXBUF>(
             &'t mut self,
-            words: &'t mut TXBUF,
+            words: &'t TXBUF,
             read_buffer: &'t mut RXBUF,
         ) -> Result<SpiDmaTransferRxTx<'t, 'd, T, C, M>, super::Error>
         where
@@ -1147,7 +1147,7 @@ pub mod dma {
             cmd: Command,
             address: Address,
             dummy: u8,
-            buffer: &'t mut TXBUF,
+            buffer: &'t TXBUF,
         ) -> Result<SpiDmaTransfer<'t, 'd, T, C, M>, super::Error>
         where
             TXBUF: ReadBuffer<Word = u8>,

esp-hal/src/spi/slave.rs

@@ -398,7 +398,7 @@ pub mod dma {
         /// The write is driven by the SPI master's sclk signal and cs line.
         pub fn dma_write<'t, TXBUF>(
             &'t mut self,
-            words: &'t mut TXBUF,
+            words: &'t TXBUF,
         ) -> Result<SpiDmaTransferTx<'t, 'd, T, C>, Error>
         where
             TXBUF: ReadBuffer<Word = u8>,
@@ -449,7 +449,7 @@ pub mod dma {
         /// line.
         pub fn dma_transfer<'t, TXBUF, RXBUF>(
             &'t mut self,
-            words: &'t mut TXBUF,
+            words: &'t TXBUF,
             read_buffer: &'t mut RXBUF,
         ) -> Result<SpiDmaTransferRxTx<'t, 'd, T, C>, Error>
         where

examples/src/bin/aes_dma.rs

@@ -31,8 +31,7 @@ fn main() -> ! {
     let dma = Dma::new(peripherals.DMA);
     let dma_channel = dma.channel0;
 
-    let (mut tx_buffer, mut tx_descriptors, mut rx_buffer, mut rx_descriptors) =
-        dma_buffers!(16, 16);
+    let (input, mut tx_descriptors, mut output, mut rx_descriptors) = dma_buffers!(16, 16);
 
     let mut aes = Aes::new(peripherals.AES).with_dma(dma_channel.configure(
         false,
@@ -42,13 +41,13 @@ fn main() -> ! {
     ));
 
     let keytext = [1u8, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16];
-    rx_buffer.copy_from_slice(&[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16]);
+    input.copy_from_slice(&[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16]);
 
     let pre_hw_encrypt = cycles();
     let transfer = aes
         .process(
-            &mut rx_buffer,
-            &mut tx_buffer,
+            &input,
+            &mut output,
             Mode::Encryption128,
             CipherMode::Ecb,
             keytext,
@@ -62,15 +61,15 @@ fn main() -> ! {
     );
 
     let mut hw_encrypted = [0u8; 16];
-    (&mut hw_encrypted[..]).copy_from_slice(tx_buffer);
+    (&mut hw_encrypted[..]).copy_from_slice(output);
 
-    rx_buffer.copy_from_slice(tx_buffer);
+    input.copy_from_slice(output);
 
     let pre_hw_decrypt = cycles();
     let transfer = aes
         .process(
-            &mut rx_buffer,
-            &mut tx_buffer,
+            &input,
+            &mut output,
             Mode::Decryption128,
             CipherMode::Ecb,
             keytext,
@@ -84,7 +83,7 @@ fn main() -> ! {
     );
 
     let mut hw_decrypted = [0u8; 16];
-    (&mut hw_decrypted[..]).copy_from_slice(tx_buffer);
+    (&mut hw_decrypted[..]).copy_from_slice(output);
 
     // create an array with aes block size
     let mut block_buf = [0_u8; 16];

examples/src/bin/i2s_sound.rs

@@ -64,7 +64,7 @@ fn main() -> ! {
     #[cfg(not(any(feature = "esp32", feature = "esp32s2")))]
     let dma_channel = dma.channel0;
 
-    let (mut tx_buffer, mut tx_descriptors, _, mut rx_descriptors) = dma_buffers!(32000, 0);
+    let (tx_buffer, mut tx_descriptors, _, mut rx_descriptors) = dma_buffers!(32000, 0);
 
     let i2s = I2s::new(
         peripherals.I2S0,
@@ -102,7 +102,7 @@ fn main() -> ! {
     }
 
     let mut filler = [0u8; 10000];
-    let mut transfer = i2s_tx.write_dma_circular(&mut tx_buffer).unwrap();
+    let mut transfer = i2s_tx.write_dma_circular(&tx_buffer).unwrap();
 
     loop {
         let avail = transfer.available();

examples/src/bin/lcd_i8080.rs

@@ -213,7 +213,7 @@ fn main() -> ! {
     let total_pixels = width as usize * height as usize;
     let total_bytes = total_pixels * 2;
 
-    let mut buffer = tx_buffer;
+    let buffer = tx_buffer;
 
     for color in [RED, BLUE].iter().cycle() {
         let color = color.to_be_bytes();
@@ -223,19 +223,19 @@ fn main() -> ! {
 
         let mut bytes_left_to_write = total_bytes;
 
-        let transfer = i8080.send_dma(0x2C, 0, &mut buffer).unwrap();
+        let transfer = i8080.send_dma(0x2C, 0, &buffer).unwrap();
         transfer.wait().unwrap();
 
         bytes_left_to_write -= buffer.len();
 
         while bytes_left_to_write >= buffer.len() {
-            let transfer = i8080.send_dma(0x3C, 0, &mut buffer).unwrap();
+            let transfer = i8080.send_dma(0x3C, 0, &buffer).unwrap();
             transfer.wait().unwrap();
 
             bytes_left_to_write -= buffer.len();
         }
         if bytes_left_to_write > 0 {
-            let transfer = i8080.send_dma(0x3C, 0, &mut buffer).unwrap();
+            let transfer = i8080.send_dma(0x3C, 0, &buffer).unwrap();
             transfer.wait().unwrap();
         }
 

examples/src/bin/parl_io_tx.rs

@@ -75,15 +75,15 @@ fn main() -> ! {
         )
         .unwrap();
 
-    let mut buffer = tx_buffer;
+    let buffer = tx_buffer;
     for i in 0..buffer.len() {
         buffer[i] = (i % 255) as u8;
     }
 
     let mut delay = Delay::new(&clocks);
 
     loop {
-        let transfer = parl_io_tx.write_dma(&mut buffer).unwrap();
+        let transfer = parl_io_tx.write_dma(&buffer).unwrap();
         transfer.wait().unwrap();
         println!("Transferred {} bytes", buffer.len());
 

examples/src/bin/qspi_flash.rs

@@ -96,8 +96,8 @@ fn main() -> ! {
     let mut delay = Delay::new(&clocks);
 
     // DMA buffer require a static life-time
-    let (mut zero_buf, _, _, _) = dma_buffers!(0);
-    let mut send = tx_buffer;
+    let (zero_buf, _, _, _) = dma_buffers!(0);
+    let send = tx_buffer;
     let mut receive = rx_buffer;
 
     // write enable
@@ -107,7 +107,7 @@ fn main() -> ! {
             Command::Command8(0x06, SpiDataMode::Single),
             Address::None,
             0,
-            &mut zero_buf,
+            &zero_buf,
         )
         .unwrap();
     transfer.wait().unwrap();
@@ -120,7 +120,7 @@ fn main() -> ! {
             Command::Command8(0x20, SpiDataMode::Single),
             Address::Address24(0x000000, SpiDataMode::Single),
             0,
-            &mut zero_buf,
+            &zero_buf,
         )
         .unwrap();
     transfer.wait().unwrap();
@@ -133,7 +133,7 @@ fn main() -> ! {
             Command::Command8(0x06, SpiDataMode::Single),
             Address::None,
             0,
-            &mut zero_buf,
+            &zero_buf,
         )
         .unwrap();
     transfer.wait().unwrap();
@@ -148,7 +148,7 @@ fn main() -> ! {
             Command::Command8(0x32, SpiDataMode::Single),
             Address::Address24(0x000000, SpiDataMode::Single),
             0,
-            &mut send,
+            &send,
         )
         .unwrap();
     transfer.wait().unwrap();