Get DMA on H7 working, add usart_dma example for H7.

examples/stm32h7/src/bin/usart_dma.rs

@@ -0,0 +1,100 @@
+#![no_std]
+#![no_main]
+#![feature(trait_alias)]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use core::fmt::Write;
+use embassy::executor::Executor;
+use embassy::time::Clock;
+use embassy::util::Forever;
+use embassy_stm32::dma::NoDma;
+use embassy_stm32::usart::{Config, Uart};
+use example_common::*;
+use embassy_traits::uart::Write as _Write;
+
+use hal::prelude::*;
+use stm32h7xx_hal as hal;
+
+use cortex_m_rt::entry;
+use stm32h7::stm32h743 as pac;
+use heapless::String;
+
+#[embassy::task]
+async fn main_task() {
+    let p = embassy_stm32::init(Default::default());
+
+    let config = Config::default();
+    let mut usart = Uart::new(p.UART7, p.PF6, p.PF7, p.DMA1_0, NoDma, config);
+
+    for n in 0u32.. {
+        let mut s: String<128> = String::new();
+        core::write!(&mut s, "Hello DMA World {}!\r\n", n).unwrap();
+
+        usart.write(s.as_bytes()).await.ok();
+
+        info!("wrote DMA");
+    }
+
+}
+
+struct ZeroClock;
+
+impl Clock for ZeroClock {
+    fn now(&self) -> u64 {
+        0
+    }
+}
+
+static EXECUTOR: Forever<Executor> = Forever::new();
+
+#[entry]
+fn main() -> ! {
+    info!("Hello World!");
+
+    let pp = pac::Peripherals::take().unwrap();
+
+    let pwrcfg = pp.PWR.constrain().freeze();
+
+    let rcc = pp.RCC.constrain();
+
+    rcc.sys_ck(96.mhz())
+        .pclk1(48.mhz())
+        .pclk2(48.mhz())
+        .pclk3(48.mhz())
+        .pclk4(48.mhz())
+        .pll1_q_ck(48.mhz())
+        .freeze(pwrcfg, &pp.SYSCFG);
+
+    let pp = unsafe { pac::Peripherals::steal() };
+
+    pp.DBGMCU.cr.modify(|_, w| {
+        w.dbgsleep_d1().set_bit();
+        w.dbgstby_d1().set_bit();
+        w.dbgstop_d1().set_bit();
+        w.d1dbgcken().set_bit();
+        w
+    });
+
+    pp.RCC.ahb4enr.modify(|_, w| {
+        w.gpioaen().set_bit();
+        w.gpioben().set_bit();
+        w.gpiocen().set_bit();
+        w.gpioden().set_bit();
+        w.gpioeen().set_bit();
+        w.gpiofen().set_bit();
+        w
+    });
+
+    unsafe { embassy::time::set_clock(&ZeroClock) };
+
+    let executor = EXECUTOR.put(Executor::new());
+
+    executor.run(|spawner| {
+        unwrap!(spawner.spawn(main_task()));
+    })
+}