Merge #792 #794

792: Add example for using a Signal. r=Dirbaio a=hydra

I didn't find an example, so I created one for the STM32H7.  Code based on the nrf mutex.rs example.

794: Fix F1 compilation by implementig AF pullup r=Dirbaio a=chemicstry

Embassy fails to compile on `STM32F103RET6`, because `set_as_af_pull` function is missing for GPIOv1:

```
error[E0599]: no method named `set_as_af_pull` found for mutable reference `&mut CLK` in the current scope
    --> C:\Users\chemi\.cargo\git\checkouts\embassy-0cff10c9b9902273\46473ae\embassy-stm32\src\sdmmc\mod.rs:1390:21
     |
1390 |             clk_pin.set_as_af_pull(clk_pin.af_num(), AFType::OutputPushPull, Pull::None);
     |                     ^^^^^^^^^^^^^^ method not found in `&mut CLK`
```

GPIOv1 actually supports pullups in AF mode, but only for inputs. The `sdmmc` driver, which was causing compile errors uses pullups for push-pull outputs and this will silently fail. But IMO not adding pullups to sdmmc interface is a hardware design problem, not HAL.

Co-authored-by: Dominic Clifton <me@dominicclifton.name>
Co-authored-by: chemicstry <chemicstry@gmail.com>
Co-authored-by: Dario Nieuwenhuis <dirbaio@dirbaio.net>

ci.sh

@@ -59,6 +59,7 @@ cargo batch  \
     --- build --release --manifest-path embassy-stm32/Cargo.toml --target thumbv6m-none-eabi --features nightly,stm32wl54jc-cm0p,defmt,exti,time-driver-any,embassy/time-tick-32768hz,unstable-traits \
     --- build --release --manifest-path embassy-stm32/Cargo.toml --target thumbv7em-none-eabi --features nightly,stm32wle5ub,defmt,exti,time-driver-any,embassy/time-tick-32768hz,unstable-traits \
     --- build --release --manifest-path embassy-stm32/Cargo.toml --target thumbv7m-none-eabi --features nightly,stm32f107vc,defmt,exti,time-driver-any,embassy/time-tick-32768hz,unstable-traits \
+    --- build --release --manifest-path embassy-stm32/Cargo.toml --target thumbv7m-none-eabi --features nightly,stm32f103re,defmt,exti,time-driver-any,embassy/time-tick-32768hz,unstable-traits \
     --- build --release --manifest-path embassy-boot/nrf/Cargo.toml --target thumbv7em-none-eabi --features embassy-nrf/nrf52840 \
     --- build --release --manifest-path embassy-boot/stm32/Cargo.toml --target thumbv7em-none-eabi --features embassy-stm32/stm32wl55jc-cm4,embassy/time-tick-32768hz \
     --- build --release --manifest-path docs/modules/ROOT/examples/basic/Cargo.toml --target thumbv7em-none-eabi \

embassy-stm32/src/gpio.rs

@@ -424,9 +424,14 @@ pub(crate) mod sealed {
             }
         }
 
+        #[inline]
+        unsafe fn set_as_af(&self, af_num: u8, af_type: AFType) {
+            self.set_as_af_pull(af_num, af_type, Pull::None);
+        }
+
         #[cfg(gpio_v1)]
         #[inline]
-        unsafe fn set_as_af(&self, _af_num: u8, af_type: AFType) {
+        unsafe fn set_as_af_pull(&self, _af_num: u8, af_type: AFType, pull: Pull) {
             // F1 uses the AFIO register for remapping.
             // For now, this is not implemented, so af_num is ignored
             // _af_num should be zero here, since it is not set by stm32-data
@@ -435,9 +440,21 @@ pub(crate) mod sealed {
             let crlh = if n < 8 { 0 } else { 1 };
             match af_type {
                 AFType::Input => {
+                    let cnf = match pull {
+                        Pull::Up => {
+                            r.bsrr().write(|w| w.set_bs(n, true));
+                            vals::CnfIn::PULL
+                        }
+                        Pull::Down => {
+                            r.bsrr().write(|w| w.set_br(n, true));
+                            vals::CnfIn::PULL
+                        }
+                        Pull::None => vals::CnfIn::FLOATING,
+                    };
+
                     r.cr(crlh).modify(|w| {
                         w.set_mode(n % 8, vals::Mode::INPUT);
-                        w.set_cnf_in(n % 8, vals::CnfIn::FLOATING);
+                        w.set_cnf_in(n % 8, cnf);
                     });
                 }
                 AFType::OutputPushPull => {
@@ -455,12 +472,6 @@ pub(crate) mod sealed {
             }
         }
 
-        #[cfg(gpio_v2)]
-        #[inline]
-        unsafe fn set_as_af(&self, af_num: u8, af_type: AFType) {
-            self.set_as_af_pull(af_num, af_type, Pull::None);
-        }
-
         #[cfg(gpio_v2)]
         #[inline]
         unsafe fn set_as_af_pull(&self, af_num: u8, af_type: AFType, pull: Pull) {

examples/stm32h7/src/bin/signal.rs

@@ -0,0 +1,41 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+// global logger
+use defmt::{info, unwrap};
+use defmt_rtt as _;
+
+use panic_probe as _;
+
+use embassy::channel::Signal;
+use embassy::executor::Spawner;
+use embassy::time::{Duration, Timer};
+
+use embassy_stm32::Peripherals;
+
+static SIGNAL: Signal<u32> = Signal::new();
+
+#[embassy::task]
+async fn my_sending_task() {
+    let mut counter: u32 = 0;
+
+    loop {
+        Timer::after(Duration::from_secs(1)).await;
+
+        SIGNAL.signal(counter);
+
+        counter = counter.wrapping_add(1);
+    }
+}
+
+#[embassy::main]
+async fn main(spawner: Spawner, _p: Peripherals) {
+    unwrap!(spawner.spawn(my_sending_task()));
+
+    loop {
+        let received_counter = SIGNAL.wait().await;
+
+        info!("signalled, counter: {}", received_counter);
+    }
+}