esp-rs · bugadani · Nov 15, 2024
diff --git a/esp-hal/CHANGELOG.md b/esp-hal/CHANGELOG.md
@@ -20,7 +20,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
-- DMA channel objects now implement `Peripheral` (#2526)
+- In addition to taking by value, peripheral drivers can now mutably borrow DMA channel objects. (#2526)
 - DMA channel objects are no longer wrapped in `Channel`. The `Channel` drivers are now managed by DMA enabled peripheral drivers. (#2526)
 - The `Dpi` driver and `DpiTransfer` now have a `Mode` type parameter. The driver's asyncness is determined by the asyncness of the `Lcd` used to create it. (#2526)
 - `dma::{Channel, ChannelRx, ChannelTx}::set_priority` for GDMA devices (#2403)
@@ -31,6 +31,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `dma::{Channel, ChannelRx, ChannelTx}::set_priority` for GDMA devices (#2403)
 - `SystemTimer`s `Alarm`s are now type erased (#2576)
 - `TimerGroup` `Timer`s are now type erased (#2581)
+- DMA channels are now available via the `Peripherals` struct, and have been renamed accordingly. (#2545)
 
 ### Fixed
 
@@ -40,6 +41,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - The DMA channel objects no longer have `tx` and `rx` fields. (#2526)
 - `SysTimerAlarms` has been removed, alarms are now part of the `SystemTimer` struct (#2576)
 - `FrozenUnit`, `AnyUnit`, `SpecificUnit`, `SpecificComparator`, `AnyComparator` have been removed from `systimer` (#2576)
+- The `Dma` structure has been removed. (#2545)
 
 ## [0.22.0] - 2024-11-20
 

diff --git a/esp-hal/MIGRATING-0.22.md b/esp-hal/MIGRATING-0.22.md
@@ -2,6 +2,20 @@
 
 ## DMA changes
 
+### Accessing channel objects
+
+DMA channels are now available through the `Peripherals` struct, which is returned
+by `esp_hal::init()`. The channels themselves have been renamed to match other peripheral signletons.
+
+- ESP32-C2, C3, C6, H2 and S3: `channelX -> DMA_CHX`
+- ESP32 and S2: `spiXchannel -> DMA_SPIX`, `i2sXchannel -> DMA_I2SX`
+
+```diff
+-let dma = Dma::new(peripherals.DMA);
+-let channel = dma.channel2;
++let channel = peripherals.DMA_CH2;
+```
+
 ### Configuration changes
 
 - `configure_for_async` and `configure` have been removed

diff --git a/esp-hal/src/dma/gdma.rs b/esp-hal/src/dma/gdma.rs
@@ -20,7 +20,6 @@ use crate::{
     macros::handler,
     peripheral::{Peripheral, PeripheralRef},
     peripherals::Interrupt,
-    system::{self, PeripheralClockControl},
 };
 
 /// An arbitrary GDMA channel
@@ -776,53 +775,10 @@ crate::impl_dma_eligible! {
     }
 }
 
-/// GDMA Peripheral
-///
-/// This offers the available DMA channels.
-pub struct Dma<'d> {
-    _inner: PeripheralRef<'d, crate::peripherals::DMA>,
-    /// Channel 0
-    pub channel0: DmaChannel0,
-    /// Channel 1
-    #[cfg(not(esp32c2))]
-    pub channel1: DmaChannel1,
-    /// Channel 2
-    #[cfg(not(esp32c2))]
-    pub channel2: DmaChannel2,
-    /// Channel 3
-    #[cfg(esp32s3)]
-    pub channel3: DmaChannel3,
-    /// Channel 4
-    #[cfg(esp32s3)]
-    pub channel4: DmaChannel4,
-}
-
-impl<'d> Dma<'d> {
-    /// Create a DMA instance.
-    pub fn new(dma: impl Peripheral<P = crate::peripherals::DMA> + 'd) -> Dma<'d> {
-        crate::into_ref!(dma);
-
-        if PeripheralClockControl::enable(system::Peripheral::Gdma) {
-            PeripheralClockControl::reset(system::Peripheral::Gdma);
-        }
-        dma.misc_conf().modify(|_, w| w.ahbm_rst_inter().set_bit());
-        dma.misc_conf()
-            .modify(|_, w| w.ahbm_rst_inter().clear_bit());
-        dma.misc_conf().modify(|_, w| w.clk_en().set_bit());
-
-        unsafe {
-            Dma {
-                _inner: dma,
-                channel0: DmaChannel0::steal(),
-                #[cfg(not(esp32c2))]
-                channel1: DmaChannel1::steal(),
-                #[cfg(not(esp32c2))]
-                channel2: DmaChannel2::steal(),
-                #[cfg(esp32s3)]
-                channel3: DmaChannel3::steal(),
-                #[cfg(esp32s3)]
-                channel4: DmaChannel4::steal(),
-            }
-        }
-    }
+pub(super) fn init_dma() {
+    let dma = unsafe { crate::soc::peripherals::DMA::steal() };
+    dma.misc_conf().modify(|_, w| w.ahbm_rst_inter().set_bit());
+    dma.misc_conf()
+        .modify(|_, w| w.ahbm_rst_inter().clear_bit());
+    dma.misc_conf().modify(|_, w| w.clk_en().set_bit());
 }
diff --git a/esp-hal/src/dma/mod.rs b/esp-hal/src/dma/mod.rs
@@ -19,10 +19,11 @@
 #![doc = crate::before_snippet!()]
 //! # use esp_hal::dma_buffers;
 //! # use esp_hal::spi::{master::{Config, Spi}, SpiMode};
-//! # use esp_hal::dma::Dma;
-//! let dma = Dma::new(peripherals.DMA);
-#![cfg_attr(any(esp32, esp32s2), doc = "let dma_channel = dma.spi2channel;")]
-#![cfg_attr(not(any(esp32, esp32s2)), doc = "let dma_channel = dma.channel0;")]
+#![cfg_attr(any(esp32, esp32s2), doc = "let dma_channel = peripherals.DMA_SPI2;")]
+#![cfg_attr(
+    not(any(esp32, esp32s2)),
+    doc = "let dma_channel = peripherals.DMA_CH0;"
+)]
 //! let sclk = peripherals.GPIO0;
 //! let miso = peripherals.GPIO2;
 //! let mosi = peripherals.GPIO4;
@@ -40,7 +41,7 @@
 //! .with_mosi(mosi)
 //! .with_miso(miso)
 //! .with_cs(cs)
-//! .with_dma(dma_channel);
+//! .with_dma(peripherals.DMA_SPI2);
 //! # }
 //! ```
 //! 
@@ -70,6 +71,7 @@ use crate::{
     peripheral::{Peripheral, PeripheralRef},
     peripherals::Interrupt,
     soc::is_slice_in_dram,
+    system,
     Async,
     Blocking,
     Cpu,
@@ -1665,7 +1667,7 @@ impl<DEG: DmaChannel> DmaChannelConvert<DEG> for DEG {
 #[cfg_attr(pdma, doc = "")]
 #[cfg_attr(
     pdma,
-    doc = "Note that using mismatching channels (e.g. trying to use `spi2channel` with SPI3) may compile, but will panic in runtime."
+    doc = "Note that using mismatching channels (e.g. trying to use `DMA_SPI2` with SPI3) may compile, but will panic in runtime."
 )]
 #[cfg_attr(pdma, doc = "")]
 /// ## Example
@@ -1679,7 +1681,6 @@ impl<DEG: DmaChannel> DmaChannelConvert<DEG> for DEG {
 /// use esp_hal::dma::DmaChannelFor;
 /// use esp_hal::peripheral::Peripheral;
 /// use esp_hal::Blocking;
-/// use esp_hal::dma::Dma;
 ///
 /// fn configures_spi_dma<'d, S, CH>(
 ///     spi: Spi<'d, Blocking, S>,
@@ -1691,10 +1692,8 @@ impl<DEG: DmaChannel> DmaChannelConvert<DEG> for DEG {
 ///  {
 ///     spi.with_dma(channel)
 /// }
-///
-/// let dma = Dma::new(peripherals.DMA);
-#[cfg_attr(pdma, doc = "let dma_channel = dma.spi2channel;")]
-#[cfg_attr(gdma, doc = "let dma_channel = dma.channel0;")]
+#[cfg_attr(pdma, doc = "let dma_channel = peripherals.DMA_SPI2;")]
+#[cfg_attr(gdma, doc = "let dma_channel = peripherals.DMA_CH0;")]
 #[doc = ""]
 /// let spi = Spi::new_with_config(
 ///     peripherals.SPI2,
@@ -1802,6 +1801,21 @@ pub trait Rx: crate::private::Sealed {
     fn waker(&self) -> &'static crate::asynch::AtomicWaker;
 }
 
+// NOTE(p4): because the P4 has two different GDMAs, we won't be able to use
+// `GenericPeripheralGuard`.
+cfg_if::cfg_if! {
+    if #[cfg(pdma)] {
+        type PeripheralGuard = system::GenericPeripheralGuard<{ system::Peripheral::Dma as u8}>;
+    } else {
+        type PeripheralGuard = system::GenericPeripheralGuard<{ system::Peripheral::Gdma as u8}>;
+    }
+}
+
+fn create_guard(_ch: &impl RegisterAccess) -> PeripheralGuard {
+    // NOTE(p4): this function will read the channel's DMA peripheral from `_ch`
+    system::GenericPeripheralGuard::new_with(init_dma)
+}
+
 // DMA receive channel
 #[non_exhaustive]
 #[doc(hidden)]
@@ -1812,6 +1826,7 @@ where
 {
     pub(crate) rx_impl: PeripheralRef<'a, CH>,
     pub(crate) _phantom: PhantomData<M>,
+    pub(crate) _guard: PeripheralGuard,
 }
 
 impl<'a, CH> ChannelRx<'a, Blocking, CH>
@@ -1821,6 +1836,9 @@ where
     /// Creates a new RX channel half.
     pub fn new(rx_impl: impl Peripheral<P = CH> + 'a) -> Self {
         crate::into_ref!(rx_impl);
+
+        let _guard = create_guard(&*rx_impl);
+
         #[cfg(gdma)]
         // clear the mem2mem mode to avoid failed DMA if this
         // channel was previously used for a mem2mem transfer.
@@ -1836,6 +1854,7 @@ where
         Self {
             rx_impl,
             _phantom: PhantomData,
+            _guard,
         }
     }
 
@@ -1848,6 +1867,7 @@ where
         ChannelRx {
             rx_impl: self.rx_impl,
             _phantom: PhantomData,
+            _guard: self._guard,
         }
     }
 
@@ -1878,6 +1898,7 @@ where
         ChannelRx {
             rx_impl: self.rx_impl,
             _phantom: PhantomData,
+            _guard: self._guard,
         }
     }
 }
@@ -2095,6 +2116,7 @@ where
 {
     pub(crate) tx_impl: PeripheralRef<'a, CH>,
     pub(crate) _phantom: PhantomData<M>,
+    pub(crate) _guard: PeripheralGuard,
 }
 
 impl<'a, CH> ChannelTx<'a, Blocking, CH>
@@ -2104,6 +2126,9 @@ where
     /// Creates a new TX channel half.
     pub fn new(tx_impl: impl Peripheral<P = CH> + 'a) -> Self {
         crate::into_ref!(tx_impl);
+
+        let _guard = create_guard(&*tx_impl);
+
         if let Some(interrupt) = tx_impl.peripheral_interrupt() {
             for cpu in Cpu::all() {
                 crate::interrupt::disable(cpu, interrupt);
@@ -2113,6 +2138,7 @@ where
         Self {
             tx_impl,
             _phantom: PhantomData,
+            _guard,
         }
     }
 
@@ -2125,6 +2151,7 @@ where
         ChannelTx {
             tx_impl: self.tx_impl,
             _phantom: PhantomData,
+            _guard: self._guard,
         }
     }
 
@@ -2155,6 +2182,7 @@ where
         ChannelTx {
             tx_impl: self.tx_impl,
             _phantom: PhantomData,
+            _guard: self._guard,
         }
     }
 }

diff --git a/esp-hal/src/dma/pdma.rs b/esp-hal/src/dma/pdma.rs
@@ -20,7 +20,6 @@ use crate::{
     macros::handler,
     peripheral::{Peripheral, PeripheralRef},
     peripherals::Interrupt,
-    system::{self, PeripheralClockControl},
 };
 
 type SpiRegisterBlock = crate::peripherals::spi2::RegisterBlock;
@@ -876,52 +875,18 @@ crate::impl_dma_eligible!([I2s0DmaChannel] I2S0 => I2s0);
 #[cfg(i2s1)]
 crate::impl_dma_eligible!([I2s1DmaChannel] I2S1 => I2s1);
 
-/// DMA Peripheral
-///
-/// This offers the available DMA channels.
-pub struct Dma<'d> {
-    _inner: PeripheralRef<'d, crate::peripherals::DMA>,
-    /// DMA channel for SPI2
-    pub spi2channel: Spi2DmaChannel,
-    /// DMA channel for SPI3
-    pub spi3channel: Spi3DmaChannel,
-    /// DMA channel for I2S0
-    pub i2s0channel: I2s0DmaChannel,
-    /// DMA channel for I2S1
-    #[cfg(i2s1)]
-    pub i2s1channel: I2s1DmaChannel,
-}
-
-impl<'d> Dma<'d> {
-    /// Create a DMA instance.
-    pub fn new(dma: impl Peripheral<P = crate::peripherals::DMA> + 'd) -> Dma<'d> {
-        if PeripheralClockControl::enable(system::Peripheral::Dma) {
-            PeripheralClockControl::reset(system::Peripheral::Dma);
-        }
-
-        #[cfg(esp32)]
-        {
-            // (only) on ESP32 we need to configure DPORT for the SPI DMA channels
-            // This assignes the DMA channels to the SPI peripherals, which is more
-            // restrictive than necessary but we currently support the same
-            // number of SPI peripherals as SPI DMA channels so it's not a big
-            // deal.
-            let dport = unsafe { &*crate::peripherals::DPORT::PTR };
-            dport.spi_dma_chan_sel().modify(|_, w| unsafe {
-                w.spi2_dma_chan_sel().bits(1).spi3_dma_chan_sel().bits(2)
-            });
-        }
-
-        unsafe {
-            Dma {
-                _inner: dma.into_ref(),
-                spi2channel: Spi2DmaChannel::steal(),
-                spi3channel: Spi3DmaChannel::steal(),
-                i2s0channel: I2s0DmaChannel::steal(),
-                #[cfg(i2s1)]
-                i2s1channel: I2s1DmaChannel::steal(),
-            }
-        }
+pub(super) fn init_dma() {
+    #[cfg(esp32)]
+    {
+        // (only) on ESP32 we need to configure DPORT for the SPI DMA channels
+        // This assignes the DMA channels to the SPI peripherals, which is more
+        // restrictive than necessary but we currently support the same
+        // number of SPI peripherals as SPI DMA channels so it's not a big
+        // deal.
+        let dport = unsafe { crate::peripherals::DPORT::steal() };
+        dport
+            .spi_dma_chan_sel()
+            .modify(|_, w| unsafe { w.spi2_dma_chan_sel().bits(1).spi3_dma_chan_sel().bits(2) });
     }
 }
 

diff --git a/esp-hal/src/i2s/master.rs b/esp-hal/src/i2s/master.rs
@@ -31,10 +31,11 @@
 #![doc = crate::before_snippet!()]
 //! # use esp_hal::i2s::master::{I2s, Standard, DataFormat};
 //! # use esp_hal::dma_buffers;
-//! # use esp_hal::dma::Dma;
-//! let dma = Dma::new(peripherals.DMA);
-#![cfg_attr(any(esp32, esp32s2), doc = "let dma_channel = dma.i2s0channel;")]
-#![cfg_attr(not(any(esp32, esp32s2)), doc = "let dma_channel = dma.channel0;")]
+#![cfg_attr(any(esp32, esp32s2), doc = "let dma_channel = peripherals.DMA_I2S0;")]
+#![cfg_attr(
+    not(any(esp32, esp32s2)),
+    doc = "let dma_channel = peripherals.DMA_CH0;"
+)]
 //! let (mut rx_buffer, rx_descriptors, _, tx_descriptors) =
 //! dma_buffers!(0, 4 * 4092);
 //!

diff --git a/esp-hal/src/lcd_cam/cam.rs b/esp-hal/src/lcd_cam/cam.rs
@@ -19,10 +19,6 @@
 //! # use esp_hal::lcd_cam::{cam::{Camera, RxEightBits}, LcdCam};
 //! # use fugit::RateExtU32;
 //! # use esp_hal::dma_rx_stream_buffer;
-//! # use esp_hal::dma::Dma;
-//!
-//! # let dma = Dma::new(peripherals.DMA);
-//! # let channel = dma.channel0;
 //!
 //! # let dma_buf = dma_rx_stream_buffer!(20 * 1000, 1000);
 //!
@@ -44,7 +40,7 @@
 //! let lcd_cam = LcdCam::new(peripherals.LCD_CAM);
 //! let mut camera = Camera::new(
 //!     lcd_cam.cam,
-//!     channel,
+//!     peripherals.DMA_CH0,
 //!     data_pins,
 //!     20u32.MHz(),
 //! )