From 0b9961584b366e6d3cc83a218c8150800793cb1d Mon Sep 17 00:00:00 2001
From: Ben Gamari <ben@smart-cactus.org>
Date: Tue, 28 Sep 2021 20:29:46 -0400
Subject: [PATCH] stm32/adc: Ensure that clock is enabled

Sadly due to the inconsistency in clocking configuration across devices
we cannot use RccPeripheral.
---
 embassy-stm32/src/adc/v3.rs | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/embassy-stm32/src/adc/v3.rs b/embassy-stm32/src/adc/v3.rs
index 5fa5b9bc..ddf06dea 100644
--- a/embassy-stm32/src/adc/v3.rs
+++ b/embassy-stm32/src/adc/v3.rs
@@ -6,6 +6,17 @@ use embedded_hal::blocking::delay::DelayUs;
 
 pub const VDDA_CALIB_MV: u32 = 3000;
 
+/// Sadly we cannot use `RccPeripheral::enable` since devices are quite inconsistent ADC clock
+/// configuration.
+unsafe fn enable() {
+    #[cfg(rcc_h7)]
+    crate::pac::RCC.apb2enr().modify(|w| w.set_adcen(true));
+    #[cfg(rcc_g0)]
+    crate::pac::RCC.apbenr2().modify(|w| w.set_adcen(true));
+    #[cfg(rcc_l4)]
+    crate::pac::RCC.ahb2enr().modify(|w| w.set_adcen(true));
+}
+
 pub enum Resolution {
     TwelveBit,
     TenBit,
@@ -196,6 +207,7 @@ impl<'d, T: Instance> Adc<'d, T> {
     pub fn new(_peri: impl Unborrow<Target = T> + 'd, delay: &mut impl DelayUs<u32>) -> Self {
         unborrow!(_peri);
         unsafe {
+            enable();
             T::regs().cr().modify(|reg| {
                 #[cfg(not(adc_g0))]
                 reg.set_deeppwd(false);