Merge pull request #240 from lulf/enable-timer-clock

Enable timer clock in RCC on timer start

embassy-macros/src/chip/stm32.rs

@@ -16,7 +16,10 @@ pub fn generate(embassy_prefix: &ModulePrefix, config: syn::Expr) -> TokenStream
             interrupt::take!(TIM2),
         );
         let clock = unsafe { make_static(&mut c) };
-        clock.start_tim2();
+
+        // TODO: Is TIM2 always APB1?
+        let timer_freq = unsafe { #embassy_stm32_path::rcc::get_freqs().apb1_clk };
+        clock.start(timer_freq);
 
         let mut alarm = clock.alarm1();
         unsafe { #embassy_path::time::set_clock(clock) };

embassy-stm32/src/clock.rs

@@ -11,6 +11,7 @@ use embassy::time::{Clock as EmbassyClock, TICKS_PER_SECOND};
 use crate::interrupt::{CriticalSection, Interrupt, Mutex};
 use crate::pac::timer::TimGp16;
 use crate::peripherals;
+use crate::rcc::RccPeripheral;
 use crate::time::Hertz;
 
 // Clock timekeeping works with something we call "periods", which are time intervals
@@ -76,27 +77,12 @@ impl<T: Instance> Clock<T> {
         }
     }
 
-    // TODO: Temporary until clock code generation is in place
-    pub fn start_tim2(&'static self) {
-        cfg_if::cfg_if! {
-            if #[cfg(rcc_l0)] {
-                unsafe {
-                    let rcc = crate::pac::RCC;
-                    rcc.apb1enr()
-                        .modify(|w| w.set_tim2en(true));
-                    rcc.apb1rstr().modify(|w| w.set_tim2rst(true));
-                    rcc.apb1rstr().modify(|w| w.set_tim2rst(false));
-                }
-
-                let timer_freq = unsafe { crate::rcc::get_freqs().apb1_clk };
-                self.start(timer_freq);
-            }
-        }
-    }
-
     pub fn start(&'static self, timer_freq: Hertz) {
         let inner = T::inner();
 
+        T::enable();
+        T::reset();
+
         // NOTE(unsafe) Critical section to use the unsafe methods
         critical_section::with(|_| {
             unsafe {
@@ -359,7 +345,7 @@ pub(crate) mod sealed {
     }
 }
 
-pub trait Instance: sealed::Instance + Sized + 'static {}
+pub trait Instance: sealed::Instance + Sized + RccPeripheral + 'static {}
 
 macro_rules! impl_timer {
     ($inst:ident) => {

stm32-metapac/gen/src/lib.rs

@@ -267,12 +267,23 @@ pub fn gen(options: Options) {
                     _ => {}
                 }
 
-                if let Some(clock) = &p.clock {
                 if let Some(rcc) = &rcc {
+                    let clock_prefix: Option<&str> = if let Some(clock) = &p.clock {
+                        Some(clock)
+                    } else if name.starts_with("TIM") {
+                        // Not all peripherals like timers the clock hint due to insufficient information from
+                        // chip definition. If clock is not specified, the first matching register with the
+                        // expected field will be used.
+                        Some("")
+                    } else {
+                        None
+                    };
+
+                    if let Some(clock_prefix) = clock_prefix {
                         // Workaround for clock registers being split on some chip families. Assume fields are
                         // named after peripheral and look for first field matching and use that register.
-                        let en = find_reg_for_field(&rcc, clock, &format!("{}EN", name));
+                        let en = find_reg_for_field(&rcc, clock_prefix, &format!("{}EN", name));
-                        let rst = find_reg_for_field(&rcc, clock, &format!("{}RST", name));
+                        let rst = find_reg_for_field(&rcc, clock_prefix, &format!("{}RST", name));
 
                         match (en, rst) {
                             (Some((enable_reg, enable_field)), Some((reset_reg, reset_field))) => {