stm32/time: add Cargo features to choose tim2/tim3

embassy-stm32/src/lib.rs

@@ -20,6 +20,7 @@ pub mod time;
 pub mod dma;
 pub mod gpio;
 pub mod rcc;
+#[cfg(feature = "_time-driver")]
 mod time_driver;
 
 // Sometimes-present hardware
@@ -88,6 +89,7 @@ pub fn init(config: Config) -> Peripherals {
         rcc::init(config.rcc);
 
         // must be after rcc init
+        #[cfg(feature = "_time-driver")]
         time_driver::init();
     }
 

embassy-stm32/src/time_driver.rs

@@ -17,8 +17,23 @@ use crate::rcc::sealed::RccPeripheral;
 use self::sealed::Instance as _;
 
 const ALARM_COUNT: usize = 3;
+
+#[cfg(feature = "time-driver-tim2")]
+type T = peripherals::TIM2;
+#[cfg(feature = "time-driver-tim3")]
 type T = peripherals::TIM3;
 
+#[cfg(feature = "time-driver-tim2")]
+#[interrupt]
+fn TIM2() {
+    STATE.on_interrupt()
+}
+#[cfg(feature = "time-driver-tim3")]
+#[interrupt]
+fn TIM3() {
+    STATE.on_interrupt()
+}
+
 // Clock timekeeping works with something we call "periods", which are time intervals
 // of 2^15 ticks. The Clock counter value is 16 bits, so one "overflow cycle" is 2 periods.
 //
@@ -275,11 +290,6 @@ impl Driver for RtcDriver {
     }
 }
 
-#[interrupt]
-fn TIM3() {
-    STATE.on_interrupt()
-}
-
 pub(crate) fn init() {
     STATE.init()
 }