From e237b8034452d1c77f108614f55ae0c46439e4f9 Mon Sep 17 00:00:00 2001
From: Richard Meadows <962920+richardeoin@users.noreply.github.com>
Date: Sun, 18 Oct 2020 23:22:20 +0200
Subject: [PATCH] Experiment with implementing TargetAddress on a HAL structure

As well as the PAC structure.

Also add the option to include an extra layer of
indirection for the target register
---
 src/dma/bdma.rs   |  5 ++++
 src/dma/macros.rs | 58 +++++++++++++++++++++++++++++++++++++++--------
 src/i2c.rs        |  5 ++++
 3 files changed, 58 insertions(+), 10 deletions(-)

diff --git a/src/dma/bdma.rs b/src/dma/bdma.rs
index 074e50633..405ded518 100644
--- a/src/dma/bdma.rs
+++ b/src/dma/bdma.rs
@@ -10,6 +10,7 @@ use super::{
 use core::marker::PhantomData;
 
 use crate::{
+    i2c::I2c,
     pac::{self, BDMA, DMAMUX2},
     rcc::{rec, rec::ResetEnable},
     //serial::{Rx, Tx},
@@ -478,4 +479,8 @@ peripheral_target_address!(
     (pac::SPI6, txdr, u8, M2P, DMAReq::SPI6_TX_DMA),
     (pac::I2C4, rxdr, u8, P2M, DMAReq::I2C4_RX_DMA),
     (pac::I2C4, txdr, u8, M2P, DMAReq::I2C4_TX_DMA),
+    (INNER, I2c<pac::I2C4>, rxdr, u8, P2M, DMAReq::I2C4_RX_DMA),
+    (INNER, I2c<pac::I2C4>, txdr, u8, M2P, DMAReq::I2C4_TX_DMA),
+);
+
 );
diff --git a/src/dma/macros.rs b/src/dma/macros.rs
index 0ebf1d757..dd4a8a8c5 100644
--- a/src/dma/macros.rs
+++ b/src/dma/macros.rs
@@ -3,24 +3,62 @@
 // Convenience macro for implementing target addresses on peripherals
 macro_rules! peripheral_target_address {
     ($(
-        ($peripheral:ty, $register:ident $(($TRBUFF:ident))*, $size:ty,
-         $dir:ty $(, $mux:expr)*)
+        $peripheral:tt
     ),+ $(,)*) => {
         $(
-            unsafe impl TargetAddress<$dir> for &mut $peripheral {
-                #[inline(always)]
-                fn address(&self) -> u32 {
-                    &self.$register as *const _ as u32
-                }
+            peripheral_target_instance!($peripheral);
+        )+
+    };
+}
+macro_rules! peripheral_target_instance {
+    (($peripheral:ty, $register:ident $(($TRBUFF:ident))*, $size:ty,
+      $dir:ty $(, $mux:expr)*)) => {
+        unsafe impl TargetAddress<$dir> for &mut $peripheral {
+            #[inline(always)]
+            fn address(&self) -> u32 {
+                &self.$register as *const _ as u32
+            }
 
-                type MemSize = $size;
+            type MemSize = $size;
+            $(
+                const REQUEST_LINE: Option<u8> = Some($mux as u8);
+            )*
                 $(
-                    const REQUEST_LINE: Option<u8> = Some($mux as u8);
+                    const $TRBUFF: bool = true;
                 )*
+        }
+    };
+
+    ((INNER, $peripheral:ty, $register:ident $(($TRBUFF:ident))*, $size:ty,
+      $dir:ty $(, $mux:expr)*)) => {
+        unsafe impl TargetAddress<$dir> for &mut $peripheral {
+            #[inline(always)]
+            fn address(&self) -> u32 {
+                &self.inner().$register as *const _ as u32
+            }
+
+            type MemSize = $size;
+            $(
+                const REQUEST_LINE: Option<u8> = Some($mux as u8);
+            )*
                 $(
                     const $TRBUFF: bool = true;
                 )*
+        }
+    };
+
+    (($peripheral:ty, $channel:ident.$register:ident, $size:ty,
+      $dir:ty $(, $mux:expr)*)) => {
+        unsafe impl TargetAddress<$dir> for &mut $peripheral {
+            #[inline(always)]
+            fn address(&self) -> u32 {
+                &self.$channel.$register as *const _ as u32
             }
-        )+
+
+            type MemSize = $size;
+            $(
+                const REQUEST_LINE: Option<u8> = Some($mux as u8);
+            )*
+        }
     };
 }
diff --git a/src/i2c.rs b/src/i2c.rs
index 8b303e006..2d8d207b1 100644
--- a/src/i2c.rs
+++ b/src/i2c.rs
@@ -313,6 +313,11 @@ macro_rules! i2c {
                     I2c { i2c }
                 }
 
+                /// Returns a reference to the inner peripheral
+                pub fn inner(&self) -> &$I2CX {
+                    &self.i2c
+                }
+
                 /// Start listening for `event`
                 pub fn listen(&mut self, event: Event) {
                     self.i2c.cr1.modify(|_,w| {