WIP: Fix ADC support for STM32L47x/L48x

Author: ejpcmac

src/adc.rs

@@ -13,6 +13,9 @@ use crate::{
     rcc::{AHB2, CCIPR},
 };
 
+// TODO: Only on STM32L47x/L48x.
+use crate::gpio::AnalogPin;
+
 #[cfg(any(feature = "stm32l4x1", feature = "stm32l4x2", feature = "stm32l4x3",))]
 use pac::ADC as ADC1;
 
@@ -101,7 +104,8 @@ impl ADC {
     }
 }
 
-impl<C> OneShot<ADC, u16, C> for ADC
+// TODO: AnalogPin only on STM32L47x/L48x.
+impl<C: AnalogPin> OneShot<ADC, u16, C> for ADC
 where
     C: Channel,
 {
@@ -126,6 +130,10 @@ where
         // Configure channel
         channel.set_sample_time(&self.inner, self.sample_time);
 
+        // TODO: Only on STM32L47x/L48x.
+        // Connect the pin to the ADC
+        channel.connect_adc();
+
         // Select channel
         self.inner.sqr1.write(|w| {
             // This is sound, as all `Channel` implementations set valid values.
@@ -157,6 +165,10 @@ where
         // Read ADC value
         let val = self.inner.dr.read().bits() as u16;
 
+        // TODO: Only on STM32L47x/L48x.
+        // Disconnect the pin from the ADC
+        channel.disconnect_adc();
+
         // Disable ADC
         self.inner.cr.modify(|_, w| w.addis().set_bit());
 

src/gpio.rs

@@ -132,6 +132,13 @@ pub trait ExtiPin {
     fn check_interrupt(&mut self) -> bool;
 }
 
+// TODO: Only on STM32L47x/L48x.
+/// Analog Pin
+pub trait AnalogPin {
+    fn connect_adc(&mut self);
+    fn disconnect_adc(&mut self);
+}
+
 macro_rules! doc_comment {
     ($x:expr, $($tt:tt)*) => {
         #[doc = $x]
@@ -188,6 +195,9 @@ macro_rules! gpio {
                 PullDown, PullUp, PushPull, State, Speed,
             };
 
+            // TODO: Only on STM32L47x/L48x.
+            use super::AnalogPin;
+
             /// GPIO parts
             pub struct Parts {
                 /// Opaque AFRH register
@@ -732,6 +742,17 @@ macro_rules! gpio {
                     }
                 }
 
+                // TODO: Only on STM32L47x/L48x.
+                impl AnalogPin for $PXi<Analog> {
+                    fn connect_adc(&mut self) {
+                        unsafe { (*$GPIOX::ptr()).ascr.modify(|r, w| w.bits(r.bits() | (1 << $i))); }
+                    }
+
+                    fn disconnect_adc(&mut self) {
+                        unsafe { (*$GPIOX::ptr()).ascr.modify(|r, w| w.bits(r.bits() & !(1 << $i))); }
+                    }
+                }
+
                 impl<MODE> $PXi<MODE> {
                     impl_into_af! {
                         $PXi $AFR $i,