Add SYSCFG wrapper, based on f4xx-hal

Author: Piroro-hs

src/lib.rs

@@ -191,6 +191,7 @@ cfg_if::cfg_if! {
         pub mod rtc;
         pub mod serial;
         pub mod spi;
+        pub mod syscfg;
         pub mod timer;
     }
 }

src/prelude.rs

@@ -6,6 +6,7 @@ pub use crate::flash::FlashExt as _stm32f3xx_hal_flash_FlashExt;
 pub use crate::gpio::GpioExt as _stm32f3xx_hal_gpio_GpioExt;
 pub use crate::hal::prelude::*;
 pub use crate::rcc::RccExt as _stm32f3xx_hal_rcc_RccExt;
+pub use crate::syscfg::SysCfgExt as _stm32f3xx_hal_syscfg_SysCfgExt;
 pub use crate::time::duration::Extensions as _stm32f3xx_hal_time_time_Extensions;
 pub use crate::time::rate::Extensions as _stm32f3xx_hal_time_rate_Extensions;
 #[cfg(feature = "unproven")]

src/syscfg.rs

@@ -0,0 +1,40 @@
+//! System configuration controller
+
+use core::ops::Deref;
+
+use crate::{pac::SYSCFG, rcc::APB2};
+
+/// Extension trait that constrains the `SYSCFG` peripheral
+pub trait SysCfgExt {
+    /// Constrains the `SYSCFG` peripheral so it plays nicely with the other abstractions
+    fn constrain(self, apb2: &mut APB2) -> SysCfg;
+}
+
+impl SysCfgExt for SYSCFG {
+    fn constrain(self, apb2: &mut APB2) -> SysCfg {
+        apb2.enr().modify(|_, w| w.syscfgen().enabled());
+
+        SysCfg(self)
+    }
+}
+
+/// Constrained SYSCFG peripheral
+///
+/// An instance of this struct is acquired by calling the
+/// [`constrain`](SysCfgExt::constrain) function on the
+/// [`SYSCFG`](crate::pac::SYSCFG) struct.
+///
+/// ```
+/// let dp = pac::Peripherals::take().unwrap();
+/// let syscfg = dp.SYSCFG.constrain();
+/// ```
+pub struct SysCfg(SYSCFG);
+
+impl Deref for SysCfg {
+    type Target = SYSCFG;
+
+    #[inline(always)]
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}