From a0db00634af3f3fa212dfe728f2c67e7b872b2f5 Mon Sep 17 00:00:00 2001
From: Ongun Kanat <ongun.kanat@egym.com>
Date: Mon, 15 Sep 2025 11:20:21 +0200
Subject: [PATCH 1/2] Implement Deref and DerefMut for Rcc

Cordoning off access to RCC registers makes implementing certain
software and drivers (e.g. a bootloader for STMF0 cores need SYSCFG)
unnecessarily difficult.

A completely encapsulated RCC renders peripheral enable registers
inaccessible and some drivers (e.g stm32_usbd) opt for using
unsafe raw pointer accesses completely eliminating the safety
and the structure provided by the HAL.

This commit copies an escape hatch from stm32f4xx-hal crate by
implementing Deref and DerefMut for Rcc structure.
The stm32f4xx-hal implementation can be seen at the link below:
https://github.com/stm32-rs/stm32f4xx-hal/blob/0ba01f4fb3f19b0eea40d8ea2403e2e9d4e41609/src/rcc/mod.rs#L56-L67
---
 src/rcc.rs | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/rcc.rs b/src/rcc.rs
index b396ad6..3a38b00 100644
--- a/src/rcc.rs
+++ b/src/rcc.rs
@@ -1,5 +1,6 @@
 use crate::pac::RCC;
 use crate::time::Hertz;
+use core::ops::{Deref, DerefMut};
 
 /// Extension trait that sets up the `RCC` peripheral
 pub trait RccExt {
@@ -45,6 +46,20 @@ pub struct Rcc {
     pub(crate) regs: RCC,
 }
 
+impl Deref for Rcc {
+    type Target = RCC;
+
+    fn deref(&self) -> &Self::Target {
+        &self.regs
+    }
+}
+
+impl DerefMut for Rcc {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.regs
+    }
+}
+
 pub enum HSEBypassMode {
     /// Not bypassed: for crystals
     NotBypassed,

From e57407971ffd1547f3a727d23f0d4da0ae09c286 Mon Sep 17 00:00:00 2001
From: Ongun Kanat <ongun.kanat@egym.com>
Date: Mon, 15 Sep 2025 11:42:23 +0200
Subject: [PATCH 2/2] Add impl Deref and DerefMut for Rcc to CHANGELOG.md

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b392951..e4f6636 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - PWM output on complementary channels only for single channel timers (TIM16 + TIM17)
 - impl embedded_hal_1::spi::SpiBus for SPI
 - impl embedded_hal_1::digital traits for Pins
+- impl core::{Deref, DerefMut} for Rcc
 
 ### Fixed