diff --git a/embassy-nrf/src/lib.rs b/embassy-nrf/src/lib.rs
index 9093ad919..e3458e2de 100644
--- a/embassy-nrf/src/lib.rs
+++ b/embassy-nrf/src/lib.rs
@@ -354,7 +354,11 @@ unsafe fn uicr_write_masked(address: *mut u32, value: u32, mask: u32) -> WriteRe
     WriteResult::Written
 }
 
-/// Initialize peripherals with the provided configuration. This should only be called once at startup.
+/// Initialize the `embassy-nrf` HAL with the provided configuration.
+///
+/// This returns the peripheral singletons that can be used for creating drivers.
+///
+/// This should only be called once at startup, otherwise it panics.
 pub fn init(config: config::Config) -> Peripherals {
     // Do this first, so that it panics if user is calling `init` a second time
     // before doing anything important.
diff --git a/embassy-stm32/build.rs b/embassy-stm32/build.rs
index bb60d244f..058b8a0fc 100644
--- a/embassy-stm32/build.rs
+++ b/embassy-stm32/build.rs
@@ -672,14 +672,14 @@ fn main() {
         (("lpuart", "RTS"), quote!(crate::usart::RtsPin)),
         (("lpuart", "CK"), quote!(crate::usart::CkPin)),
         (("lpuart", "DE"), quote!(crate::usart::DePin)),
-        (("sai", "SCK_A"), quote!(crate::sai::SckAPin)),
-        (("sai", "SCK_B"), quote!(crate::sai::SckBPin)),
-        (("sai", "FS_A"), quote!(crate::sai::FsAPin)),
-        (("sai", "FS_B"), quote!(crate::sai::FsBPin)),
-        (("sai", "SD_A"), quote!(crate::sai::SdAPin)),
-        (("sai", "SD_B"), quote!(crate::sai::SdBPin)),
-        (("sai", "MCLK_A"), quote!(crate::sai::MclkAPin)),
-        (("sai", "MCLK_B"), quote!(crate::sai::MclkBPin)),
+        (("sai", "SCK_A"), quote!(crate::sai::SckPin<A>)),
+        (("sai", "SCK_B"), quote!(crate::sai::SckPin<B>)),
+        (("sai", "FS_A"), quote!(crate::sai::FsPin<A>)),
+        (("sai", "FS_B"), quote!(crate::sai::FsPin<B>)),
+        (("sai", "SD_A"), quote!(crate::sai::SdPin<A>)),
+        (("sai", "SD_B"), quote!(crate::sai::SdPin<B>)),
+        (("sai", "MCLK_A"), quote!(crate::sai::MclkPin<A>)),
+        (("sai", "MCLK_B"), quote!(crate::sai::MclkPin<B>)),
         (("sai", "WS"), quote!(crate::sai::WsPin)),
         (("spi", "SCK"), quote!(crate::spi::SckPin)),
         (("spi", "MOSI"), quote!(crate::spi::MosiPin)),
@@ -995,8 +995,8 @@ fn main() {
         (("usart", "TX"), quote!(crate::usart::TxDma)),
         (("lpuart", "RX"), quote!(crate::usart::RxDma)),
         (("lpuart", "TX"), quote!(crate::usart::TxDma)),
-        (("sai", "A"), quote!(crate::sai::DmaA)),
-        (("sai", "B"), quote!(crate::sai::DmaB)),
+        (("sai", "A"), quote!(crate::sai::Dma<A>)),
+        (("sai", "B"), quote!(crate::sai::Dma<B>)),
         (("spi", "RX"), quote!(crate::spi::RxDma)),
         (("spi", "TX"), quote!(crate::spi::TxDma)),
         (("i2c", "RX"), quote!(crate::i2c::RxDma)),
diff --git a/embassy-stm32/src/adc/mod.rs b/embassy-stm32/src/adc/mod.rs
index ff523ca3b..e4dd35c34 100644
--- a/embassy-stm32/src/adc/mod.rs
+++ b/embassy-stm32/src/adc/mod.rs
@@ -1,4 +1,5 @@
-//! Analog to Digital (ADC) converter driver.
+//! Analog to Digital Converter (ADC)
+
 #![macro_use]
 #![allow(missing_docs)] // TODO
 
diff --git a/embassy-stm32/src/can/mod.rs b/embassy-stm32/src/can/mod.rs
index 425f9ac2e..915edb3a6 100644
--- a/embassy-stm32/src/can/mod.rs
+++ b/embassy-stm32/src/can/mod.rs
@@ -1,3 +1,4 @@
+//! Controller Area Network (CAN)
 #![macro_use]
 
 #[cfg_attr(can_bxcan, path = "bxcan.rs")]
diff --git a/embassy-stm32/src/crc/mod.rs b/embassy-stm32/src/crc/mod.rs
index 63f7ad9ba..29523b92d 100644
--- a/embassy-stm32/src/crc/mod.rs
+++ b/embassy-stm32/src/crc/mod.rs
@@ -1,3 +1,4 @@
+//! Cyclic Redundancy Check (CRC)
 #[cfg_attr(crc_v1, path = "v1.rs")]
 #[cfg_attr(crc_v2, path = "v2v3.rs")]
 #[cfg_attr(crc_v3, path = "v2v3.rs")]
diff --git a/embassy-stm32/src/dac/mod.rs b/embassy-stm32/src/dac/mod.rs
index 9c670195d..31dedf06e 100644
--- a/embassy-stm32/src/dac/mod.rs
+++ b/embassy-stm32/src/dac/mod.rs
@@ -1,4 +1,4 @@
-//! Provide access to the STM32 digital-to-analog converter (DAC).
+//! Digital to Analog Converter (DAC)
 #![macro_use]
 
 use core::marker::PhantomData;
diff --git a/embassy-stm32/src/dcmi.rs b/embassy-stm32/src/dcmi.rs
index 139d8fd1b..4d02284b2 100644
--- a/embassy-stm32/src/dcmi.rs
+++ b/embassy-stm32/src/dcmi.rs
@@ -1,3 +1,4 @@
+//! Digital Camera Interface (DCMI)
 use core::future::poll_fn;
 use core::marker::PhantomData;
 use core::task::Poll;
diff --git a/embassy-stm32/src/eth/mod.rs b/embassy-stm32/src/eth/mod.rs
index dbf91eedc..448405507 100644
--- a/embassy-stm32/src/eth/mod.rs
+++ b/embassy-stm32/src/eth/mod.rs
@@ -1,3 +1,4 @@
+//! Ethernet (ETH)
 #![macro_use]
 
 #[cfg_attr(any(eth_v1a, eth_v1b, eth_v1c), path = "v1/mod.rs")]
diff --git a/embassy-stm32/src/exti.rs b/embassy-stm32/src/exti.rs
index 371be913e..f83bae3ff 100644
--- a/embassy-stm32/src/exti.rs
+++ b/embassy-stm32/src/exti.rs
@@ -1,3 +1,4 @@
+//! External Interrupts (EXTI)
 use core::convert::Infallible;
 use core::future::Future;
 use core::marker::PhantomData;
diff --git a/embassy-stm32/src/flash/mod.rs b/embassy-stm32/src/flash/mod.rs
index 6b6b4d41c..cbf5c25b2 100644
--- a/embassy-stm32/src/flash/mod.rs
+++ b/embassy-stm32/src/flash/mod.rs
@@ -1,3 +1,4 @@
+//! Flash memory (FLASH)
 use embedded_storage::nor_flash::{NorFlashError, NorFlashErrorKind};
 
 #[cfg(flash_f4)]
diff --git a/embassy-stm32/src/fmc.rs b/embassy-stm32/src/fmc.rs
index 23ac82f63..873c8a70c 100644
--- a/embassy-stm32/src/fmc.rs
+++ b/embassy-stm32/src/fmc.rs
@@ -1,3 +1,4 @@
+//! Flexible Memory Controller (FMC) / Flexible Static Memory Controller (FSMC)
 use core::marker::PhantomData;
 
 use embassy_hal_internal::into_ref;
diff --git a/embassy-stm32/src/hrtim/mod.rs b/embassy-stm32/src/hrtim/mod.rs
index 17096d48c..6539326b4 100644
--- a/embassy-stm32/src/hrtim/mod.rs
+++ b/embassy-stm32/src/hrtim/mod.rs
@@ -1,3 +1,5 @@
+//! High Resolution Timer (HRTIM)
+
 mod traits;
 
 use core::marker::PhantomData;
diff --git a/embassy-stm32/src/i2c/mod.rs b/embassy-stm32/src/i2c/mod.rs
index 0af291e9c..9b0b35eca 100644
--- a/embassy-stm32/src/i2c/mod.rs
+++ b/embassy-stm32/src/i2c/mod.rs
@@ -1,3 +1,4 @@
+//! Inter-Integrated-Circuit (I2C)
 #![macro_use]
 
 #[cfg_attr(i2c_v1, path = "v1.rs")]
diff --git a/embassy-stm32/src/i2s.rs b/embassy-stm32/src/i2s.rs
index 372c86db3..1f85c0bc5 100644
--- a/embassy-stm32/src/i2s.rs
+++ b/embassy-stm32/src/i2s.rs
@@ -1,3 +1,4 @@
+//! Inter-IC Sound (I2S)
 use embassy_hal_internal::into_ref;
 
 use crate::gpio::sealed::{AFType, Pin as _};
diff --git a/embassy-stm32/src/lib.rs b/embassy-stm32/src/lib.rs
index 5d9b4e6a0..fd691a732 100644
--- a/embassy-stm32/src/lib.rs
+++ b/embassy-stm32/src/lib.rs
@@ -149,15 +149,33 @@ use crate::interrupt::Priority;
 pub use crate::pac::NVIC_PRIO_BITS;
 use crate::rcc::sealed::RccPeripheral;
 
+/// `embassy-stm32` global configuration.
 #[non_exhaustive]
 pub struct Config {
+    /// RCC config.
     pub rcc: rcc::Config,
+
+    /// Enable debug during sleep.
+    ///
+    /// May incrase power consumption. Defaults to true.
     #[cfg(dbgmcu)]
     pub enable_debug_during_sleep: bool,
+
+    /// BDMA interrupt priority.
+    ///
+    /// Defaults to P0 (highest).
     #[cfg(bdma)]
     pub bdma_interrupt_priority: Priority,
+
+    /// DMA interrupt priority.
+    ///
+    /// Defaults to P0 (highest).
     #[cfg(dma)]
     pub dma_interrupt_priority: Priority,
+
+    /// GPDMA interrupt priority.
+    ///
+    /// Defaults to P0 (highest).
     #[cfg(gpdma)]
     pub gpdma_interrupt_priority: Priority,
 }
@@ -178,7 +196,11 @@ impl Default for Config {
     }
 }
 
-/// Initialize embassy.
+/// Initialize the `embassy-stm32` HAL with the provided configuration.
+///
+/// This returns the peripheral singletons that can be used for creating drivers.
+///
+/// This should only be called once at startup, otherwise it panics.
 pub fn init(config: Config) -> Peripherals {
     critical_section::with(|cs| {
         let p = Peripherals::take_with_cs(cs);
diff --git a/embassy-stm32/src/qspi/mod.rs b/embassy-stm32/src/qspi/mod.rs
index bac91f300..9ea0a726c 100644
--- a/embassy-stm32/src/qspi/mod.rs
+++ b/embassy-stm32/src/qspi/mod.rs
@@ -1,3 +1,5 @@
+//! Quad Serial Peripheral Interface (QSPI)
+
 #![macro_use]
 
 pub mod enums;
diff --git a/embassy-stm32/src/rng.rs b/embassy-stm32/src/rng.rs
index b2196b0d5..6ee89a922 100644
--- a/embassy-stm32/src/rng.rs
+++ b/embassy-stm32/src/rng.rs
@@ -1,3 +1,4 @@
+//! Random Number Generator (RNG)
 #![macro_use]
 
 use core::future::poll_fn;
diff --git a/embassy-stm32/src/rtc/mod.rs b/embassy-stm32/src/rtc/mod.rs
index fa359cdae..11b252139 100644
--- a/embassy-stm32/src/rtc/mod.rs
+++ b/embassy-stm32/src/rtc/mod.rs
@@ -1,4 +1,4 @@
-//! RTC peripheral abstraction
+//! Real Time Clock (RTC)
 mod datetime;
 
 #[cfg(feature = "low-power")]
@@ -163,7 +163,7 @@ impl RtcTimeProvider {
     }
 }
 
-/// RTC Abstraction
+/// RTC driver.
 pub struct Rtc {
     #[cfg(feature = "low-power")]
     stop_time: Mutex<CriticalSectionRawMutex, Cell<Option<RtcInstant>>>,
diff --git a/embassy-stm32/src/sai/mod.rs b/embassy-stm32/src/sai/mod.rs
index 3d7f65996..ef8802184 100644
--- a/embassy-stm32/src/sai/mod.rs
+++ b/embassy-stm32/src/sai/mod.rs
@@ -1,8 +1,11 @@
+//! Serial Audio Interface (SAI)
 #![macro_use]
 
-use embassy_embedded_hal::SetConfig;
+use core::marker::PhantomData;
+
 use embassy_hal_internal::{into_ref, PeripheralRef};
 
+use self::sealed::WhichSubBlock;
 pub use crate::dma::word;
 use crate::dma::{ringbuffer, Channel, ReadableRingBuffer, Request, TransferOptions, WritableRingBuffer};
 use crate::gpio::sealed::{AFType, Pin as _};
@@ -11,48 +14,32 @@ use crate::pac::sai::{vals, Sai as Regs};
 use crate::rcc::RccPeripheral;
 use crate::{peripherals, Peripheral};
 
+/// SAI error
 #[derive(Debug, PartialEq, Eq)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum Error {
+    /// `write` called on a SAI in receive mode.
     NotATransmitter,
+    /// `read` called on a SAI in transmit mode.
     NotAReceiver,
-    OverrunError,
+    /// Overrun
+    Overrun,
 }
 
 impl From<ringbuffer::OverrunError> for Error {
     fn from(_: ringbuffer::OverrunError) -> Self {
-        Self::OverrunError
+        Self::Overrun
     }
 }
 
+/// Master/slave mode.
 #[derive(Copy, Clone)]
-pub enum SyncBlock {
-    None,
-    Sai1BlockA,
-    Sai1BlockB,
-    Sai2BlockA,
-    Sai2BlockB,
-}
-
-#[derive(Copy, Clone)]
-pub enum SyncIn {
-    None,
-    ChannelZero,
-    ChannelOne,
-}
-
-#[derive(Copy, Clone)]
+#[allow(missing_docs)]
 pub enum Mode {
     Master,
     Slave,
 }
 
-#[derive(Copy, Clone)]
-pub enum TxRx {
-    Transmitter,
-    Receiver,
-}
-
 impl Mode {
     #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
     const fn mode(&self, tx_rx: TxRx) -> vals::Mode {
@@ -69,7 +56,17 @@ impl Mode {
     }
 }
 
+/// Direction: transmit or receive
 #[derive(Copy, Clone)]
+#[allow(missing_docs)]
+pub enum TxRx {
+    Transmitter,
+    Receiver,
+}
+
+/// Data slot size.
+#[derive(Copy, Clone)]
+#[allow(missing_docs)]
 pub enum SlotSize {
     DataSize,
     /// 16 bit data length on 16 bit wide channel
@@ -80,7 +77,7 @@ pub enum SlotSize {
 
 impl SlotSize {
     #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
-    pub const fn slotsz(&self) -> vals::Slotsz {
+    const fn slotsz(&self) -> vals::Slotsz {
         match self {
             SlotSize::DataSize => vals::Slotsz::DATASIZE,
             SlotSize::Channel16 => vals::Slotsz::BIT16,
@@ -89,7 +86,9 @@ impl SlotSize {
     }
 }
 
+/// Data size.
 #[derive(Copy, Clone)]
+#[allow(missing_docs)]
 pub enum DataSize {
     Data8,
     Data10,
@@ -101,7 +100,7 @@ pub enum DataSize {
 
 impl DataSize {
     #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
-    pub const fn ds(&self) -> vals::Ds {
+    const fn ds(&self) -> vals::Ds {
         match self {
             DataSize::Data8 => vals::Ds::BIT8,
             DataSize::Data10 => vals::Ds::BIT10,
@@ -113,7 +112,9 @@ impl DataSize {
     }
 }
 
+/// FIFO threshold level.
 #[derive(Copy, Clone)]
+#[allow(missing_docs)]
 pub enum FifoThreshold {
     Empty,
     Quarter,
@@ -124,7 +125,7 @@ pub enum FifoThreshold {
 
 impl FifoThreshold {
     #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
-    pub const fn fth(&self) -> vals::Fth {
+    const fn fth(&self) -> vals::Fth {
         match self {
             FifoThreshold::Empty => vals::Fth::EMPTY,
             FifoThreshold::Quarter => vals::Fth::QUARTER1,
@@ -135,38 +136,9 @@ impl FifoThreshold {
     }
 }
 
+/// Output value on mute.
 #[derive(Copy, Clone)]
-pub enum FifoLevel {
-    Empty,
-    FirstQuarter,
-    SecondQuarter,
-    ThirdQuarter,
-    FourthQuarter,
-    Full,
-}
-
-#[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
-impl From<vals::Flvl> for FifoLevel {
-    fn from(flvl: vals::Flvl) -> Self {
-        match flvl {
-            vals::Flvl::EMPTY => FifoLevel::Empty,
-            vals::Flvl::QUARTER1 => FifoLevel::FirstQuarter,
-            vals::Flvl::QUARTER2 => FifoLevel::SecondQuarter,
-            vals::Flvl::QUARTER3 => FifoLevel::ThirdQuarter,
-            vals::Flvl::QUARTER4 => FifoLevel::FourthQuarter,
-            vals::Flvl::FULL => FifoLevel::Full,
-            _ => FifoLevel::Empty,
-        }
-    }
-}
-
-#[derive(Copy, Clone)]
-pub enum MuteDetection {
-    NoMute,
-    Mute,
-}
-
-#[derive(Copy, Clone)]
+#[allow(missing_docs)]
 pub enum MuteValue {
     Zero,
     LastValue,
@@ -174,7 +146,7 @@ pub enum MuteValue {
 
 impl MuteValue {
     #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
-    pub const fn muteval(&self) -> vals::Muteval {
+    const fn muteval(&self) -> vals::Muteval {
         match self {
             MuteValue::Zero => vals::Muteval::SENDZERO,
             MuteValue::LastValue => vals::Muteval::SENDLAST,
@@ -182,13 +154,9 @@ impl MuteValue {
     }
 }
 
+/// Protocol variant to use.
 #[derive(Copy, Clone)]
-pub enum OverUnderStatus {
-    NoError,
-    OverUnderRunDetected,
-}
-
-#[derive(Copy, Clone)]
+#[allow(missing_docs)]
 pub enum Protocol {
     Free,
     Spdif,
@@ -197,7 +165,7 @@ pub enum Protocol {
 
 impl Protocol {
     #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
-    pub const fn prtcfg(&self) -> vals::Prtcfg {
+    const fn prtcfg(&self) -> vals::Prtcfg {
         match self {
             Protocol::Free => vals::Prtcfg::FREE,
             Protocol::Spdif => vals::Prtcfg::SPDIF,
@@ -206,7 +174,9 @@ impl Protocol {
     }
 }
 
+/// Sync input between SAI units/blocks.
 #[derive(Copy, Clone, PartialEq)]
+#[allow(missing_docs)]
 pub enum SyncInput {
     /// Not synced to any other SAI unit.
     None,
@@ -218,7 +188,7 @@ pub enum SyncInput {
 }
 
 impl SyncInput {
-    pub const fn syncen(&self) -> vals::Syncen {
+    const fn syncen(&self) -> vals::Syncen {
         match self {
             SyncInput::None => vals::Syncen::ASYNCHRONOUS,
             SyncInput::Internal => vals::Syncen::INTERNAL,
@@ -228,8 +198,10 @@ impl SyncInput {
     }
 }
 
+/// SAI instance to sync from.
 #[cfg(sai_v4)]
 #[derive(Copy, Clone, PartialEq)]
+#[allow(missing_docs)]
 pub enum SyncInputInstance {
     #[cfg(peri_sai1)]
     Sai1 = 0,
@@ -241,7 +213,9 @@ pub enum SyncInputInstance {
     Sai4 = 3,
 }
 
+/// Channels (stereo or mono).
 #[derive(Copy, Clone, PartialEq)]
+#[allow(missing_docs)]
 pub enum StereoMono {
     Stereo,
     Mono,
@@ -249,7 +223,7 @@ pub enum StereoMono {
 
 impl StereoMono {
     #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
-    pub const fn mono(&self) -> vals::Mono {
+    const fn mono(&self) -> vals::Mono {
         match self {
             StereoMono::Stereo => vals::Mono::STEREO,
             StereoMono::Mono => vals::Mono::MONO,
@@ -257,15 +231,18 @@ impl StereoMono {
     }
 }
 
+/// Bit order
 #[derive(Copy, Clone)]
 pub enum BitOrder {
+    /// Least significant bit first.
     LsbFirst,
+    /// Most significant bit first.
     MsbFirst,
 }
 
 impl BitOrder {
     #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
-    pub const fn lsbfirst(&self) -> vals::Lsbfirst {
+    const fn lsbfirst(&self) -> vals::Lsbfirst {
         match self {
             BitOrder::LsbFirst => vals::Lsbfirst::LSBFIRST,
             BitOrder::MsbFirst => vals::Lsbfirst::MSBFIRST,
@@ -273,6 +250,7 @@ impl BitOrder {
     }
 }
 
+/// Frame sync offset.
 #[derive(Copy, Clone)]
 pub enum FrameSyncOffset {
     /// This is used in modes other than standard I2S phillips mode
@@ -283,7 +261,7 @@ pub enum FrameSyncOffset {
 
 impl FrameSyncOffset {
     #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
-    pub const fn fsoff(&self) -> vals::Fsoff {
+    const fn fsoff(&self) -> vals::Fsoff {
         match self {
             FrameSyncOffset::OnFirstBit => vals::Fsoff::ONFIRST,
             FrameSyncOffset::BeforeFirstBit => vals::Fsoff::BEFOREFIRST,
@@ -291,15 +269,18 @@ impl FrameSyncOffset {
     }
 }
 
+/// Frame sync polarity
 #[derive(Copy, Clone)]
 pub enum FrameSyncPolarity {
+    /// Sync signal is active low.
     ActiveLow,
+    /// Sync signal is active high
     ActiveHigh,
 }
 
 impl FrameSyncPolarity {
     #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
-    pub const fn fspol(&self) -> vals::Fspol {
+    const fn fspol(&self) -> vals::Fspol {
         match self {
             FrameSyncPolarity::ActiveLow => vals::Fspol::FALLINGEDGE,
             FrameSyncPolarity::ActiveHigh => vals::Fspol::RISINGEDGE,
@@ -307,7 +288,9 @@ impl FrameSyncPolarity {
     }
 }
 
+/// Sync definition.
 #[derive(Copy, Clone)]
+#[allow(missing_docs)]
 pub enum FrameSyncDefinition {
     StartOfFrame,
     ChannelIdentification,
@@ -315,7 +298,7 @@ pub enum FrameSyncDefinition {
 
 impl FrameSyncDefinition {
     #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
-    pub const fn fsdef(&self) -> bool {
+    const fn fsdef(&self) -> bool {
         match self {
             FrameSyncDefinition::StartOfFrame => false,
             FrameSyncDefinition::ChannelIdentification => true,
@@ -323,7 +306,9 @@ impl FrameSyncDefinition {
     }
 }
 
+/// Clock strobe.
 #[derive(Copy, Clone)]
+#[allow(missing_docs)]
 pub enum ClockStrobe {
     Falling,
     Rising,
@@ -331,7 +316,7 @@ pub enum ClockStrobe {
 
 impl ClockStrobe {
     #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
-    pub const fn ckstr(&self) -> vals::Ckstr {
+    const fn ckstr(&self) -> vals::Ckstr {
         match self {
             ClockStrobe::Falling => vals::Ckstr::FALLINGEDGE,
             ClockStrobe::Rising => vals::Ckstr::RISINGEDGE,
@@ -339,7 +324,9 @@ impl ClockStrobe {
     }
 }
 
+/// Complements format for negative samples.
 #[derive(Copy, Clone)]
+#[allow(missing_docs)]
 pub enum ComplementFormat {
     OnesComplement,
     TwosComplement,
@@ -347,7 +334,7 @@ pub enum ComplementFormat {
 
 impl ComplementFormat {
     #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
-    pub const fn cpl(&self) -> vals::Cpl {
+    const fn cpl(&self) -> vals::Cpl {
         match self {
             ComplementFormat::OnesComplement => vals::Cpl::ONESCOMPLEMENT,
             ComplementFormat::TwosComplement => vals::Cpl::TWOSCOMPLEMENT,
@@ -355,7 +342,9 @@ impl ComplementFormat {
     }
 }
 
+/// Companding setting.
 #[derive(Copy, Clone)]
+#[allow(missing_docs)]
 pub enum Companding {
     None,
     MuLaw,
@@ -364,7 +353,7 @@ pub enum Companding {
 
 impl Companding {
     #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
-    pub const fn comp(&self) -> vals::Comp {
+    const fn comp(&self) -> vals::Comp {
         match self {
             Companding::None => vals::Comp::NOCOMPANDING,
             Companding::MuLaw => vals::Comp::MULAW,
@@ -373,7 +362,9 @@ impl Companding {
     }
 }
 
+/// Output drive
 #[derive(Copy, Clone)]
+#[allow(missing_docs)]
 pub enum OutputDrive {
     OnStart,
     Immediately,
@@ -381,7 +372,7 @@ pub enum OutputDrive {
 
 impl OutputDrive {
     #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
-    pub const fn outdriv(&self) -> vals::Outdriv {
+    const fn outdriv(&self) -> vals::Outdriv {
         match self {
             OutputDrive::OnStart => vals::Outdriv::ONSTART,
             OutputDrive::Immediately => vals::Outdriv::IMMEDIATELY,
@@ -389,7 +380,9 @@ impl OutputDrive {
     }
 }
 
+/// Master clock divider.
 #[derive(Copy, Clone, PartialEq)]
+#[allow(missing_docs)]
 pub enum MasterClockDivider {
     MasterClockDisabled,
     Div1,
@@ -412,7 +405,7 @@ pub enum MasterClockDivider {
 
 impl MasterClockDivider {
     #[cfg(any(sai_v1, sai_v2, sai_v3, sai_v4))]
-    pub const fn mckdiv(&self) -> u8 {
+    const fn mckdiv(&self) -> u8 {
         match self {
             MasterClockDivider::MasterClockDisabled => 0,
             MasterClockDivider::Div1 => 0,
@@ -436,6 +429,7 @@ impl MasterClockDivider {
 }
 
 /// [`SAI`] configuration.
+#[allow(missing_docs)]
 #[non_exhaustive]
 #[derive(Copy, Clone)]
 pub struct Config {
@@ -459,7 +453,7 @@ pub struct Config {
     pub clock_strobe: ClockStrobe,
     pub output_drive: OutputDrive,
     pub master_clock_divider: MasterClockDivider,
-    pub is_high_impedenane_on_inactive_slot: bool,
+    pub is_high_impedance_on_inactive_slot: bool,
     pub fifo_threshold: FifoThreshold,
     pub companding: Companding,
     pub complement_format: ComplementFormat,
@@ -490,7 +484,7 @@ impl Default for Config {
             master_clock_divider: MasterClockDivider::MasterClockDisabled,
             clock_strobe: ClockStrobe::Rising,
             output_drive: OutputDrive::Immediately,
-            is_high_impedenane_on_inactive_slot: false,
+            is_high_impedance_on_inactive_slot: false,
             fifo_threshold: FifoThreshold::ThreeQuarters,
             companding: Companding::None,
             complement_format: ComplementFormat::TwosComplement,
@@ -501,23 +495,10 @@ impl Default for Config {
 }
 
 impl Config {
-    pub fn new_i2s() -> Self {
+    /// Create a new config with all default values.
+    pub fn new() -> Self {
         return Default::default();
     }
-
-    pub fn new_msb_first() -> Self {
-        Self {
-            bit_order: BitOrder::MsbFirst,
-            frame_sync_offset: FrameSyncOffset::OnFirstBit,
-            ..Default::default()
-        }
-    }
-}
-
-#[derive(Copy, Clone)]
-enum WhichSubBlock {
-    A = 0,
-    B = 1,
 }
 
 enum RingBuffer<'d, C: Channel, W: word::Word> {
@@ -531,28 +512,6 @@ fn dr<W: word::Word>(w: crate::pac::sai::Sai, sub_block: WhichSubBlock) -> *mut
     ch.dr().as_ptr() as _
 }
 
-pub struct SubBlock<'d, T: Instance, C: Channel, W: word::Word> {
-    _peri: PeripheralRef<'d, T>,
-    sd: Option<PeripheralRef<'d, AnyPin>>,
-    fs: Option<PeripheralRef<'d, AnyPin>>,
-    sck: Option<PeripheralRef<'d, AnyPin>>,
-    mclk: Option<PeripheralRef<'d, AnyPin>>,
-    ring_buffer: RingBuffer<'d, C, W>,
-    sub_block: WhichSubBlock,
-}
-
-pub struct SubBlockA {}
-pub struct SubBlockB {}
-
-pub struct SubBlockAPeripheral<'d, T>(PeripheralRef<'d, T>);
-pub struct SubBlockBPeripheral<'d, T>(PeripheralRef<'d, T>);
-
-pub struct Sai<'d, T: Instance> {
-    _peri: PeripheralRef<'d, T>,
-    sub_block_a_peri: Option<SubBlockAPeripheral<'d, T>>,
-    sub_block_b_peri: Option<SubBlockBPeripheral<'d, T>>,
-}
-
 // return the type for (sd, sck)
 fn get_af_types(mode: Mode, tx_rx: TxRx) -> (AFType, AFType) {
     (
@@ -591,34 +550,6 @@ fn get_ring_buffer<'d, T: Instance, C: Channel, W: word::Word>(
     }
 }
 
-impl<'d, T: Instance> Sai<'d, T> {
-    pub fn new(peri: impl Peripheral<P = T> + 'd) -> Self {
-        T::enable_and_reset();
-
-        Self {
-            _peri: unsafe { peri.clone_unchecked().into_ref() },
-            sub_block_a_peri: Some(SubBlockAPeripheral(unsafe { peri.clone_unchecked().into_ref() })),
-            sub_block_b_peri: Some(SubBlockBPeripheral(peri.into_ref())),
-        }
-    }
-
-    pub fn take_sub_block_a(self: &mut Self) -> Option<SubBlockAPeripheral<'d, T>> {
-        if self.sub_block_a_peri.is_some() {
-            self.sub_block_a_peri.take()
-        } else {
-            None
-        }
-    }
-
-    pub fn take_sub_block_b(self: &mut Self) -> Option<SubBlockBPeripheral<'d, T>> {
-        if self.sub_block_b_peri.is_some() {
-            self.sub_block_b_peri.take()
-        } else {
-            None
-        }
-    }
-}
-
 fn update_synchronous_config(config: &mut Config) {
     config.mode = Mode::Slave;
     config.sync_output = false;
@@ -636,19 +567,58 @@ fn update_synchronous_config(config: &mut Config) {
     }
 }
 
-impl SubBlockA {
-    pub fn new_asynchronous_with_mclk<'d, T: Instance, C: Channel, W: word::Word>(
-        peri: SubBlockAPeripheral<'d, T>,
-        sck: impl Peripheral<P = impl SckAPin<T>> + 'd,
-        sd: impl Peripheral<P = impl SdAPin<T>> + 'd,
-        fs: impl Peripheral<P = impl FsAPin<T>> + 'd,
-        mclk: impl Peripheral<P = impl MclkAPin<T>> + 'd,
+/// SAI subblock instance.
+pub struct SubBlock<'d, T, S: SubBlockInstance> {
+    peri: PeripheralRef<'d, T>,
+    _phantom: PhantomData<S>,
+}
+
+/// Split the main SAIx peripheral into the two subblocks.
+///
+/// You can then create a [`Sai`] driver for each each half.
+pub fn split_subblocks<'d, T: Instance>(peri: impl Peripheral<P = T> + 'd) -> (SubBlock<'d, T, A>, SubBlock<'d, T, B>) {
+    into_ref!(peri);
+    T::enable_and_reset();
+
+    (
+        SubBlock {
+            peri: unsafe { peri.clone_unchecked() },
+            _phantom: PhantomData,
+        },
+        SubBlock {
+            peri,
+            _phantom: PhantomData,
+        },
+    )
+}
+
+/// SAI sub-block driver.
+pub struct Sai<'d, T: Instance, C: Channel, W: word::Word> {
+    _peri: PeripheralRef<'d, T>,
+    sd: Option<PeripheralRef<'d, AnyPin>>,
+    fs: Option<PeripheralRef<'d, AnyPin>>,
+    sck: Option<PeripheralRef<'d, AnyPin>>,
+    mclk: Option<PeripheralRef<'d, AnyPin>>,
+    ring_buffer: RingBuffer<'d, C, W>,
+    sub_block: WhichSubBlock,
+}
+
+impl<'d, T: Instance, C: Channel, W: word::Word> Sai<'d, T, C, W> {
+    /// Create a new SAI driver in asynchronous mode with MCLK.
+    ///
+    /// You can obtain the [`SubBlock`] with [`split_subblocks`].
+    pub fn new_asynchronous_with_mclk<S: SubBlockInstance>(
+        peri: SubBlock<'d, T, S>,
+        sck: impl Peripheral<P = impl SckPin<T, S>> + 'd,
+        sd: impl Peripheral<P = impl SdPin<T, S>> + 'd,
+        fs: impl Peripheral<P = impl FsPin<T, S>> + 'd,
+        mclk: impl Peripheral<P = impl MclkPin<T, S>> + 'd,
         dma: impl Peripheral<P = C> + 'd,
         dma_buf: &'d mut [W],
         mut config: Config,
-    ) -> SubBlock<'d, T, C, W>
+    ) -> Self
     where
-        C: Channel + DmaA<T>,
+        C: Channel + Dma<T, S>,
     {
         into_ref!(mclk);
 
@@ -664,19 +634,22 @@ impl SubBlockA {
         Self::new_asynchronous(peri, sck, sd, fs, dma, dma_buf, config)
     }
 
-    pub fn new_asynchronous<'d, T: Instance, C: Channel, W: word::Word>(
-        peri: SubBlockAPeripheral<'d, T>,
-        sck: impl Peripheral<P = impl SckAPin<T>> + 'd,
-        sd: impl Peripheral<P = impl SdAPin<T>> + 'd,
-        fs: impl Peripheral<P = impl FsAPin<T>> + 'd,
+    /// Create a new SAI driver in asynchronous mode without MCLK.
+    ///
+    /// You can obtain the [`SubBlock`] with [`split_subblocks`].
+    pub fn new_asynchronous<S: SubBlockInstance>(
+        peri: SubBlock<'d, T, S>,
+        sck: impl Peripheral<P = impl SckPin<T, S>> + 'd,
+        sd: impl Peripheral<P = impl SdPin<T, S>> + 'd,
+        fs: impl Peripheral<P = impl FsPin<T, S>> + 'd,
         dma: impl Peripheral<P = C> + 'd,
         dma_buf: &'d mut [W],
         config: Config,
-    ) -> SubBlock<'d, T, C, W>
+    ) -> Self
     where
-        C: Channel + DmaA<T>,
+        C: Channel + Dma<T, S>,
     {
-        let peri = peri.0;
+        let peri = peri.peri;
         into_ref!(peri, dma, sck, sd, fs);
 
         let (sd_af_type, ck_af_type) = get_af_types(config.mode, config.tx_rx);
@@ -688,10 +661,10 @@ impl SubBlockA {
         fs.set_as_af(fs.af_num(), ck_af_type);
         fs.set_speed(crate::gpio::Speed::VeryHigh);
 
-        let sub_block = WhichSubBlock::A;
+        let sub_block = S::WHICH;
         let request = dma.request();
 
-        SubBlock::new_inner(
+        Self::new_inner(
             peri,
             sub_block,
             Some(sck.map_into()),
@@ -703,19 +676,22 @@ impl SubBlockA {
         )
     }
 
-    pub fn new_synchronous<'d, T: Instance, C: Channel, W: word::Word>(
-        peri: SubBlockAPeripheral<'d, T>,
-        sd: impl Peripheral<P = impl SdAPin<T>> + 'd,
+    /// Create a new SAI driver in synchronous mode.
+    ///
+    /// You can obtain the [`SubBlock`] with [`split_subblocks`].
+    pub fn new_synchronous<S: SubBlockInstance>(
+        peri: SubBlock<'d, T, S>,
+        sd: impl Peripheral<P = impl SdPin<T, S>> + 'd,
         dma: impl Peripheral<P = C> + 'd,
         dma_buf: &'d mut [W],
         mut config: Config,
-    ) -> SubBlock<'d, T, C, W>
+    ) -> Self
     where
-        C: Channel + DmaA<T>,
+        C: Channel + Dma<T, S>,
     {
         update_synchronous_config(&mut config);
 
-        let peri = peri.0;
+        let peri = peri.peri;
         into_ref!(dma, peri, sd);
 
         let (sd_af_type, _ck_af_type) = get_af_types(config.mode, config.tx_rx);
@@ -723,10 +699,10 @@ impl SubBlockA {
         sd.set_as_af(sd.af_num(), sd_af_type);
         sd.set_speed(crate::gpio::Speed::VeryHigh);
 
-        let sub_block = WhichSubBlock::A;
+        let sub_block = S::WHICH;
         let request = dma.request();
 
-        SubBlock::new_inner(
+        Self::new_inner(
             peri,
             sub_block,
             None,
@@ -737,129 +713,6 @@ impl SubBlockA {
             config,
         )
     }
-}
-
-impl SubBlockB {
-    pub fn new_asynchronous_with_mclk<'d, T: Instance, C: Channel, W: word::Word>(
-        peri: SubBlockBPeripheral<'d, T>,
-        sck: impl Peripheral<P = impl SckBPin<T>> + 'd,
-        sd: impl Peripheral<P = impl SdBPin<T>> + 'd,
-        fs: impl Peripheral<P = impl FsBPin<T>> + 'd,
-        mclk: impl Peripheral<P = impl MclkBPin<T>> + 'd,
-        dma: impl Peripheral<P = C> + 'd,
-        dma_buf: &'d mut [W],
-        mut config: Config,
-    ) -> SubBlock<'d, T, C, W>
-    where
-        C: Channel + DmaB<T>,
-    {
-        into_ref!(mclk);
-
-        let (_sd_af_type, ck_af_type) = get_af_types(config.mode, config.tx_rx);
-
-        mclk.set_as_af(mclk.af_num(), ck_af_type);
-        mclk.set_speed(crate::gpio::Speed::VeryHigh);
-
-        if config.master_clock_divider == MasterClockDivider::MasterClockDisabled {
-            config.master_clock_divider = MasterClockDivider::Div1;
-        }
-
-        Self::new_asynchronous(peri, sck, sd, fs, dma, dma_buf, config)
-    }
-
-    pub fn new_asynchronous<'d, T: Instance, C: Channel, W: word::Word>(
-        peri: SubBlockBPeripheral<'d, T>,
-        sck: impl Peripheral<P = impl SckBPin<T>> + 'd,
-        sd: impl Peripheral<P = impl SdBPin<T>> + 'd,
-        fs: impl Peripheral<P = impl FsBPin<T>> + 'd,
-        dma: impl Peripheral<P = C> + 'd,
-        dma_buf: &'d mut [W],
-        config: Config,
-    ) -> SubBlock<'d, T, C, W>
-    where
-        C: Channel + DmaB<T>,
-    {
-        let peri = peri.0;
-        into_ref!(dma, peri, sck, sd, fs);
-
-        let (sd_af_type, ck_af_type) = get_af_types(config.mode, config.tx_rx);
-
-        sd.set_as_af(sd.af_num(), sd_af_type);
-        sd.set_speed(crate::gpio::Speed::VeryHigh);
-
-        sck.set_as_af(sck.af_num(), ck_af_type);
-        sck.set_speed(crate::gpio::Speed::VeryHigh);
-        fs.set_as_af(fs.af_num(), ck_af_type);
-        fs.set_speed(crate::gpio::Speed::VeryHigh);
-
-        let sub_block = WhichSubBlock::B;
-        let request = dma.request();
-
-        SubBlock::new_inner(
-            peri,
-            sub_block,
-            Some(sck.map_into()),
-            None,
-            Some(sd.map_into()),
-            Some(fs.map_into()),
-            get_ring_buffer::<T, C, W>(dma, dma_buf, request, sub_block, config.tx_rx),
-            config,
-        )
-    }
-
-    pub fn new_synchronous<'d, T: Instance, C: Channel, W: word::Word>(
-        peri: SubBlockBPeripheral<'d, T>,
-        sd: impl Peripheral<P = impl SdBPin<T>> + 'd,
-        dma: impl Peripheral<P = C> + 'd,
-        dma_buf: &'d mut [W],
-        mut config: Config,
-    ) -> SubBlock<'d, T, C, W>
-    where
-        C: Channel + DmaB<T>,
-    {
-        update_synchronous_config(&mut config);
-        let peri = peri.0;
-        into_ref!(dma, peri, sd);
-
-        let (sd_af_type, _ck_af_type) = get_af_types(config.mode, config.tx_rx);
-
-        sd.set_as_af(sd.af_num(), sd_af_type);
-        sd.set_speed(crate::gpio::Speed::VeryHigh);
-
-        let sub_block = WhichSubBlock::B;
-        let request = dma.request();
-
-        SubBlock::new_inner(
-            peri,
-            sub_block,
-            None,
-            None,
-            Some(sd.map_into()),
-            None,
-            get_ring_buffer::<T, C, W>(dma, dma_buf, request, sub_block, config.tx_rx),
-            config,
-        )
-    }
-}
-
-impl<'d, T: Instance, C: Channel, W: word::Word> SubBlock<'d, T, C, W> {
-    pub fn start(self: &mut Self) {
-        match self.ring_buffer {
-            RingBuffer::Writable(ref mut rb) => {
-                rb.start();
-            }
-            RingBuffer::Readable(ref mut rb) => {
-                rb.start();
-            }
-        }
-    }
-
-    fn is_transmitter(ring_buffer: &RingBuffer<C, W>) -> bool {
-        match ring_buffer {
-            RingBuffer::Writable(_) => true,
-            _ => false,
-        }
-    }
 
     fn new_inner(
         peri: impl Peripheral<P = T> + 'd,
@@ -929,7 +782,7 @@ impl<'d, T: Instance, C: Channel, W: word::Word> SubBlock<'d, T, C, W> {
                 w.set_cpl(config.complement_format.cpl());
                 w.set_muteval(config.mute_value.muteval());
                 w.set_mutecnt(config.mute_detection_counter.0 as u8);
-                w.set_tris(config.is_high_impedenane_on_inactive_slot);
+                w.set_tris(config.is_high_impedance_on_inactive_slot);
             });
 
             ch.frcr().modify(|w| {
@@ -965,10 +818,31 @@ impl<'d, T: Instance, C: Channel, W: word::Word> SubBlock<'d, T, C, W> {
         }
     }
 
+    /// Start the SAI driver.
+    pub fn start(&mut self) {
+        match self.ring_buffer {
+            RingBuffer::Writable(ref mut rb) => {
+                rb.start();
+            }
+            RingBuffer::Readable(ref mut rb) => {
+                rb.start();
+            }
+        }
+    }
+
+    fn is_transmitter(ring_buffer: &RingBuffer<C, W>) -> bool {
+        match ring_buffer {
+            RingBuffer::Writable(_) => true,
+            _ => false,
+        }
+    }
+
+    /// Reset SAI operation.
     pub fn reset() {
         T::enable_and_reset();
     }
 
+    /// Flush.
     pub fn flush(&mut self) {
         let ch = T::REGS.ch(self.sub_block as usize);
         ch.cr1().modify(|w| w.set_saien(false));
@@ -983,19 +857,18 @@ impl<'d, T: Instance, C: Channel, W: word::Word> SubBlock<'d, T, C, W> {
         ch.cr1().modify(|w| w.set_saien(true));
     }
 
+    /// Enable or disable mute.
     pub fn set_mute(&mut self, value: bool) {
         let ch = T::REGS.ch(self.sub_block as usize);
         ch.cr2().modify(|w| w.set_mute(value));
     }
 
-    #[allow(dead_code)]
-    /// Reconfigures it with the supplied config.
-    fn reconfigure(&mut self, _config: Config) {}
-
-    pub fn get_current_config(&self) -> Config {
-        Config::default()
-    }
-
+    /// Write data to the SAI ringbuffer.
+    ///
+    /// This appends the data to the buffer and returns immediately. The
+    /// data will be transmitted in the background.
+    ///
+    /// If there's no space in the buffer, this waits until there is.
     pub async fn write(&mut self, data: &[W]) -> Result<(), Error> {
         match &mut self.ring_buffer {
             RingBuffer::Writable(buffer) => {
@@ -1006,6 +879,12 @@ impl<'d, T: Instance, C: Channel, W: word::Word> SubBlock<'d, T, C, W> {
         }
     }
 
+    /// Read data from the SAI ringbuffer.
+    ///
+    /// SAI is always receiving data in the background. This function pops already-received
+    /// data from the buffer.
+    ///
+    /// If there's less than `data.len()` data in the buffer, this waits until there is.
     pub async fn read(&mut self, data: &mut [W]) -> Result<(), Error> {
         match &mut self.ring_buffer {
             RingBuffer::Readable(buffer) => {
@@ -1017,7 +896,7 @@ impl<'d, T: Instance, C: Channel, W: word::Word> SubBlock<'d, T, C, W> {
     }
 }
 
-impl<'d, T: Instance, C: Channel, W: word::Word> Drop for SubBlock<'d, T, C, W> {
+impl<'d, T: Instance, C: Channel, W: word::Word> Drop for Sai<'d, T, C, W> {
     fn drop(&mut self) {
         let ch = T::REGS.ch(self.sub_block as usize);
         ch.cr1().modify(|w| w.set_saien(false));
@@ -1034,22 +913,43 @@ pub(crate) mod sealed {
     pub trait Instance {
         const REGS: Regs;
     }
+
+    #[derive(Copy, Clone)]
+    pub enum WhichSubBlock {
+        A = 0,
+        B = 1,
+    }
+
+    pub trait SubBlock {
+        const WHICH: WhichSubBlock;
+    }
 }
 
-pub trait Word: word::Word {}
+/// Sub-block instance trait.
+pub trait SubBlockInstance: sealed::SubBlock {}
 
+/// Sub-block A.
+pub enum A {}
+impl sealed::SubBlock for A {
+    const WHICH: WhichSubBlock = WhichSubBlock::A;
+}
+impl SubBlockInstance for A {}
+
+/// Sub-block B.
+pub enum B {}
+impl sealed::SubBlock for B {
+    const WHICH: WhichSubBlock = WhichSubBlock::B;
+}
+impl SubBlockInstance for B {}
+
+/// SAI instance trait.
 pub trait Instance: Peripheral<P = Self> + sealed::Instance + RccPeripheral {}
-pin_trait!(SckAPin, Instance);
-pin_trait!(SckBPin, Instance);
-pin_trait!(FsAPin, Instance);
-pin_trait!(FsBPin, Instance);
-pin_trait!(SdAPin, Instance);
-pin_trait!(SdBPin, Instance);
-pin_trait!(MclkAPin, Instance);
-pin_trait!(MclkBPin, Instance);
+pin_trait!(SckPin, Instance, SubBlockInstance);
+pin_trait!(FsPin, Instance, SubBlockInstance);
+pin_trait!(SdPin, Instance, SubBlockInstance);
+pin_trait!(MclkPin, Instance, SubBlockInstance);
 
-dma_trait!(DmaA, Instance);
-dma_trait!(DmaB, Instance);
+dma_trait!(Dma, Instance, SubBlockInstance);
 
 foreach_peripheral!(
     (sai, $inst:ident) => {
@@ -1060,13 +960,3 @@ foreach_peripheral!(
         impl Instance for peripherals::$inst {}
     };
 );
-
-impl<'d, T: Instance> SetConfig for Sai<'d, T> {
-    type Config = Config;
-    type ConfigError = ();
-    fn set_config(&mut self, _config: &Self::Config) -> Result<(), ()> {
-        // self.reconfigure(*config);
-
-        Ok(())
-    }
-}
diff --git a/embassy-stm32/src/sdmmc/mod.rs b/embassy-stm32/src/sdmmc/mod.rs
index 27a12062c..6099b9f43 100644
--- a/embassy-stm32/src/sdmmc/mod.rs
+++ b/embassy-stm32/src/sdmmc/mod.rs
@@ -1,3 +1,4 @@
+//! Secure Digital / MultiMedia Card (SDMMC)
 #![macro_use]
 
 use core::default::Default;
diff --git a/embassy-stm32/src/spi/mod.rs b/embassy-stm32/src/spi/mod.rs
index 92599c75e..5a1ad3e91 100644
--- a/embassy-stm32/src/spi/mod.rs
+++ b/embassy-stm32/src/spi/mod.rs
@@ -1,3 +1,4 @@
+//! Serial Peripheral Interface (SPI)
 #![macro_use]
 
 use core::ptr;
diff --git a/embassy-stm32/src/traits.rs b/embassy-stm32/src/traits.rs
index b4166e71a..13f695821 100644
--- a/embassy-stm32/src/traits.rs
+++ b/embassy-stm32/src/traits.rs
@@ -1,18 +1,18 @@
 #![macro_use]
 
 macro_rules! pin_trait {
-    ($signal:ident, $instance:path) => {
+    ($signal:ident, $instance:path $(, $mode:path)?) => {
         #[doc = concat!(stringify!($signal), " pin trait")]
-        pub trait $signal<T: $instance>: crate::gpio::Pin {
-            #[doc = concat!("Get the AF number needed to use this pin as", stringify!($signal))]
+        pub trait $signal<T: $instance $(, M: $mode)?>: crate::gpio::Pin {
+            #[doc = concat!("Get the AF number needed to use this pin as ", stringify!($signal))]
             fn af_num(&self) -> u8;
         }
     };
 }
 
 macro_rules! pin_trait_impl {
-    (crate::$mod:ident::$trait:ident, $instance:ident, $pin:ident, $af:expr) => {
-        impl crate::$mod::$trait<crate::peripherals::$instance> for crate::peripherals::$pin {
+    (crate::$mod:ident::$trait:ident$(<$mode:ident>)?, $instance:ident, $pin:ident, $af:expr) => {
+        impl crate::$mod::$trait<crate::peripherals::$instance $(, crate::$mod::$mode)?> for crate::peripherals::$pin {
             fn af_num(&self) -> u8 {
                 $af
             }
@@ -23,9 +23,9 @@ macro_rules! pin_trait_impl {
 // ====================
 
 macro_rules! dma_trait {
-    ($signal:ident, $instance:path) => {
+    ($signal:ident, $instance:path$(, $mode:path)?) => {
         #[doc = concat!(stringify!($signal), " DMA request trait")]
-        pub trait $signal<T: $instance>: crate::dma::Channel {
+        pub trait $signal<T: $instance $(, M: $mode)?>: crate::dma::Channel {
             #[doc = concat!("Get the DMA request number needed to use this channel as", stringify!($signal))]
             /// Note: in some chips, ST calls this the "channel", and calls channels "streams".
             /// `embassy-stm32` always uses the "channel" and "request number" names.
@@ -37,8 +37,8 @@ macro_rules! dma_trait {
 #[allow(unused)]
 macro_rules! dma_trait_impl {
     // DMAMUX
-    (crate::$mod:ident::$trait:ident, $instance:ident, {dmamux: $dmamux:ident}, $request:expr) => {
-        impl<T> crate::$mod::$trait<crate::peripherals::$instance> for T
+    (crate::$mod:ident::$trait:ident$(<$mode:ident>)?, $instance:ident, {dmamux: $dmamux:ident}, $request:expr) => {
+        impl<T> crate::$mod::$trait<crate::peripherals::$instance $(, crate::$mod::$mode)?> for T
         where
             T: crate::dma::Channel + crate::dma::MuxChannel<Mux = crate::dma::$dmamux>,
         {
@@ -49,8 +49,8 @@ macro_rules! dma_trait_impl {
     };
 
     // DMAMUX
-    (crate::$mod:ident::$trait:ident, $instance:ident, {dma: $dma:ident}, $request:expr) => {
-        impl<T> crate::$mod::$trait<crate::peripherals::$instance> for T
+    (crate::$mod:ident::$trait:ident$(<$mode:ident>)?, $instance:ident, {dma: $dma:ident}, $request:expr) => {
+        impl<T> crate::$mod::$trait<crate::peripherals::$instance $(, crate::$mod::$mode)?> for T
         where
             T: crate::dma::Channel,
         {
@@ -61,8 +61,8 @@ macro_rules! dma_trait_impl {
     };
 
     // DMA/GPDMA, without DMAMUX
-    (crate::$mod:ident::$trait:ident, $instance:ident, {channel: $channel:ident}, $request:expr) => {
-        impl crate::$mod::$trait<crate::peripherals::$instance> for crate::peripherals::$channel {
+    (crate::$mod:ident::$trait:ident$(<$mode:ident>)?, $instance:ident, {channel: $channel:ident}, $request:expr) => {
+        impl crate::$mod::$trait<crate::peripherals::$instance $(, crate::$mod::$mode)?> for crate::peripherals::$channel {
             fn request(&self) -> crate::dma::Request {
                 $request
             }
diff --git a/embassy-stm32/src/uid.rs b/embassy-stm32/src/uid.rs
index 6dcfcb96e..aa13586f8 100644
--- a/embassy-stm32/src/uid.rs
+++ b/embassy-stm32/src/uid.rs
@@ -1,3 +1,5 @@
+//! Unique ID (UID)
+
 /// Get this device's unique 96-bit ID.
 pub fn uid() -> &'static [u8; 12] {
     unsafe { &*crate::pac::UID.uid(0).as_ptr().cast::<[u8; 12]>() }
diff --git a/embassy-stm32/src/usart/mod.rs b/embassy-stm32/src/usart/mod.rs
index dfa1f3a6a..e2e3bd3eb 100644
--- a/embassy-stm32/src/usart/mod.rs
+++ b/embassy-stm32/src/usart/mod.rs
@@ -1,3 +1,4 @@
+//! Universal Synchronous/Asynchronous Receiver Transmitter (USART, UART, LPUART)
 #![macro_use]
 
 use core::future::poll_fn;
diff --git a/embassy-stm32/src/usb_otg/mod.rs b/embassy-stm32/src/usb_otg/mod.rs
index be54a3d10..1abd031dd 100644
--- a/embassy-stm32/src/usb_otg/mod.rs
+++ b/embassy-stm32/src/usb_otg/mod.rs
@@ -1,3 +1,5 @@
+//! USB On The Go (OTG)
+
 use crate::rcc::RccPeripheral;
 use crate::{interrupt, peripherals};
 
diff --git a/embassy-stm32/src/wdg/mod.rs b/embassy-stm32/src/wdg/mod.rs
index c7c2694e0..5751a9ff3 100644
--- a/embassy-stm32/src/wdg/mod.rs
+++ b/embassy-stm32/src/wdg/mod.rs
@@ -1,3 +1,4 @@
+//! Watchdog Timer (IWDG, WWDG)
 use core::marker::PhantomData;
 
 use embassy_hal_internal::{into_ref, Peripheral};