esp32: Block ADC2 usage simultaneously with radio (#3876)

* block `ADC2` usage simultaneously with radio (esp32)

* implement `Drop` for `ADC2` (esp32)

fmt

format

* multiple fixes

* make functions internal, lint package

* Cleanup

* use `fetch_or` instead

* take it easy

esp-hal/CHANGELOG.md

@@ -22,6 +22,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - PSRAM on ESP32-S2 (#3811)
 - WDT now allows configuring longer timeouts (#3816)
+- `ADC2` now cannot be used simultaneously with `radio` on ESP32 (#3876)
 
 ### Removed
 

esp-hal/src/analog/adc/esp32.rs

@@ -1,10 +1,43 @@
-use core::marker::PhantomData;
+use core::{
+    marker::PhantomData,
+    sync::atomic::{AtomicBool, Ordering},
+};
 
 use super::{AdcConfig, Attenuation};
-use crate::peripherals::{ADC1, ADC2, RTC_IO, SENS};
+use crate::{
+    peripherals::{ADC1, ADC2, RTC_IO, SENS},
+    private::{self},
+};
 
 pub(super) const NUM_ATTENS: usize = 10;
 
+// ADC2 cannot be used with `radio` functionality on `esp32`, this global helps us to track it's
+// state to prevent unexpected behaviour
+static ADC2_IN_USE: AtomicBool = AtomicBool::new(false);
+
+/// ADC Error
+#[derive(Debug)]
+pub enum Error {
+    /// `ADC2` is used together with `radio`.
+    Adc2InUse,
+}
+
+#[doc(hidden)]
+/// Tries to "claim" `ADC2` peripheral and set its status
+pub fn try_claim_adc2(_: private::Internal) -> Result<(), Error> {
+    if ADC2_IN_USE.fetch_or(true, Ordering::Relaxed) {
+        Err(Error::Adc2InUse)
+    } else {
+        Ok(())
+    }
+}
+
+#[doc(hidden)]
+/// Resets `ADC2` usage status to `Unused`
+pub fn release_adc2(_: private::Internal) {
+    ADC2_IN_USE.store(false, Ordering::Relaxed);
+}
+
 /// The sampling/readout resolution of the ADC.
 #[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
@@ -44,6 +77,8 @@ pub trait RegisterAccess {
     fn read_done_sar() -> bool;
 
     fn read_data_sar() -> u16;
+
+    fn instance_number() -> u8;
 }
 
 impl RegisterAccess for ADC1<'_> {
@@ -119,6 +154,10 @@ impl RegisterAccess for ADC1<'_> {
             .meas1_data_sar()
             .bits()
     }
+
+    fn instance_number() -> u8 {
+        1
+    }
 }
 
 impl RegisterAccess for ADC2<'_> {
@@ -194,6 +233,10 @@ impl RegisterAccess for ADC2<'_> {
             .meas2_data_sar()
             .bits()
     }
+
+    fn instance_number() -> u8 {
+        2
+    }
 }
 
 /// Analog-to-Digital Converter peripheral driver.
@@ -210,7 +253,18 @@ where
 {
     /// Configure a given ADC instance using the provided configuration, and
     /// initialize the ADC for use
+    ///
+    /// # Panics
+    ///
+    /// `ADC2` cannot be used simultaneously with `radio` functionalities, otherwise this function
+    /// will panic.
     pub fn new(adc_instance: ADCI, config: AdcConfig<ADCI>) -> Self {
+        if ADCI::instance_number() == 2 && try_claim_adc2(private::Internal).is_err() {
+            panic!(
+                "ADC2 is already in use by Radio. On ESP32, ADC2 cannot be used simultaneously with Wi-Fi or Bluetooth."
+            );
+        }
+
         let sensors = SENS::regs();
 
         // Set reading and sampling resolution
@@ -372,3 +426,9 @@ mod adc_implementation {
         ]
     }
 }
+
+impl Drop for ADC2<'_> {
+    fn drop(&mut self) {
+        release_adc2(private::Internal);
+    }
+}

esp-radio/CHANGELOG.md

@@ -25,7 +25,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Fixed a BLE panic caused by unimplemented functions (#3762)
 - Fixed the BLE stack crashing in certain cases (#3854)
-
+- `ADC2` now cannot be used simultaneously with `radio` on ESP32 (#3876)
 
 ### Removed
 

esp-radio/src/lib.rs

@@ -114,6 +114,8 @@ use common_adapter::chip_specific::phy_mem_init;
 use esp_config::*;
 use esp_hal::{self as hal};
 use esp_radio_preempt_driver as preempt;
+#[cfg(esp32)]
+use hal::analog::adc::{release_adc2, try_claim_adc2};
 use hal::{
     clock::{Clocks, init_radio_clocks},
     time::Rate,
@@ -217,6 +219,10 @@ impl Drop for Controller<'_> {
 
         // This shuts down the task switcher and timer tick interrupt.
         preempt::disable();
+
+        #[cfg(esp32)]
+        // Allow using `ADC2` again
+        release_adc2(unsafe { esp_hal::Internal::conjure() });
     }
 }
 
@@ -224,6 +230,11 @@ impl Drop for Controller<'_> {
 ///
 /// Make sure to **not** call this function while interrupts are disabled.
 pub fn init<'d>() -> Result<Controller<'d>, InitializationError> {
+    #[cfg(esp32)]
+    if try_claim_adc2(unsafe { hal::Internal::conjure() }).is_err() {
+        return Err(InitializationError::Adc2IsUsed);
+    }
+
     if crate::is_interrupts_disabled() {
         return Err(InitializationError::InterruptsDisabled);
     }
@@ -294,6 +305,9 @@ pub enum InitializationError {
     InterruptsDisabled,
     /// The scheduler is not initialized.
     SchedulerNotInitialized,
+    #[cfg(esp32)]
+    // ADC2 cannot be used with `radio` functionality on `esp32`.
+    Adc2IsUsed,
 }
 
 #[cfg(feature = "wifi")]