Merge #842

842: WIP: Make unborrow safe to use r=Dirbaio a=GrantM11235

The basic idea is that `Unborrow::unborrow` is now safe to call and returns an `Unborrowed<'a, T>` which impls `Deref` and `DerefMut`

```rust
/// This is essentially a `&mut T`, but it is the size of `T` not the size
/// of a pointer. This is useful if T is a zero sized type.
pub struct Unborrowed<'a, T> {
    inner: T,
    _lifetime: PhantomData<&'a mut T>,
}
```

## Todo

- [x] Update other crates
  - [x] embassy-cortex-m
  - [x] embassy-hal-common
  - [x] embassy-lora
  - [x] embassy-nrf
  - [x] embassy-rp
  - [x] embassy-stm32
- [x] Remove usage of the unsafe `into_inner` method if possible
- [x] Review and amend docs for `Unborrow` and `Unborrowed`

Co-authored-by: Grant Miller <[email protected]>
Co-authored-by: Dario Nieuwenhuis <[email protected]>

1 files changed, 8 insertions, 3 deletions

diff --git a/examples/stm32f4/src/bin/sdmmc.rs b/examples/stm32f4/src/bin/sdmmc.rs
index 665670261..752ad57bf 100644
--- a/examples/stm32f4/src/bin/sdmmc.rs
+++ b/examples/stm32f4/src/bin/sdmmc.rs
@@ -21,12 +21,17 @@ async fn main(_spawner: Spawner, p: Peripherals) -> ! {
 
     let irq = interrupt::take!(SDIO);
 
-    let mut sdmmc = Sdmmc::new(
+    let mut sdmmc = Sdmmc::new_4bit(
         p.SDIO,
-        (p.PC12, p.PD2, p.PC8, p.PC9, p.PC10, p.PC11),
         irq,
-        Default::default(),
         p.DMA2_CH3,
+        p.PC12,
+        p.PD2,
+        p.PC8,
+        p.PC9,
+        p.PC10,
+        p.PC11,
+        Default::default(),
     );
 
     // Should print 400kHz for initialization