Merge pull request #2652 from timokroeger/stm32-ucpd

STM32 USB Type-C/USB Power Delivery Interface (UCPD)

1 files changed, 86 insertions, 0 deletions

diff --git a/examples/stm32g4/src/bin/usb_c_pd.rs b/examples/stm32g4/src/bin/usb_c_pd.rs
new file mode 100644
index 000000000..7caea634f
--- /dev/null
+++ b/examples/stm32g4/src/bin/usb_c_pd.rs
@@ -0,0 +1,86 @@
+#![no_std]
+#![no_main]
+
+use defmt::{error, info, Format};
+use embassy_executor::Spawner;
+use embassy_stm32::ucpd::{self, CcPhy, CcPull, CcSel, CcVState, Ucpd};
+use embassy_stm32::{bind_interrupts, peripherals, Config};
+use embassy_time::{with_timeout, Duration};
+use {defmt_rtt as _, panic_probe as _};
+
+bind_interrupts!(struct Irqs {
+    UCPD1 => ucpd::InterruptHandler<peripherals::UCPD1>;
+});
+
+#[derive(Debug, Format)]
+enum CableOrientation {
+    Normal,
+    Flipped,
+    DebugAccessoryMode,
+}
+
+// Returns true when the cable
+async fn wait_attached<T: ucpd::Instance>(cc_phy: &mut CcPhy<'_, T>) -> CableOrientation {
+    loop {
+        let (cc1, cc2) = cc_phy.vstate();
+        if cc1 == CcVState::LOWEST && cc2 == CcVState::LOWEST {
+            // Detached, wait until attached by monitoring the CC lines.
+            cc_phy.wait_for_vstate_change().await;
+            continue;
+        }
+
+        // Attached, wait for CC lines to be stable for tCCDebounce (100..200ms).
+        if with_timeout(Duration::from_millis(100), cc_phy.wait_for_vstate_change())
+            .await
+            .is_ok()
+        {
+            // State has changed, restart detection procedure.
+            continue;
+        };
+
+        // State was stable for the complete debounce period, check orientation.
+        return match (cc1, cc2) {
+            (_, CcVState::LOWEST) => CableOrientation::Normal,  // CC1 connected
+            (CcVState::LOWEST, _) => CableOrientation::Flipped, // CC2 connected
+            _ => CableOrientation::DebugAccessoryMode,          // Both connected (special cable)
+        };
+    }
+}
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let mut config = Config::default();
+    config.enable_ucpd1_dead_battery = true;
+    let p = embassy_stm32::init(config);
+
+    info!("Hello World!");
+
+    let mut ucpd = Ucpd::new(p.UCPD1, Irqs {}, p.PB6, p.PB4);
+    ucpd.cc_phy().set_pull(CcPull::Sink);
+
+    info!("Waiting for USB connection...");
+    let cable_orientation = wait_attached(ucpd.cc_phy()).await;
+    info!("USB cable connected, orientation: {}", cable_orientation);
+
+    let cc_sel = match cable_orientation {
+        CableOrientation::Normal => {
+            info!("Starting PD communication on CC1 pin");
+            CcSel::CC1
+        }
+        CableOrientation::Flipped => {
+            info!("Starting PD communication on CC2 pin");
+            CcSel::CC2
+        }
+        CableOrientation::DebugAccessoryMode => panic!("No PD communication in DAM"),
+    };
+    let (_cc_phy, mut pd_phy) = ucpd.split_pd_phy(p.DMA1_CH1, p.DMA1_CH2, cc_sel);
+
+    loop {
+        // Enough space for the longest non-extended data message.
+        let mut buf = [0_u8; 30];
+        match pd_phy.receive(buf.as_mut()).await {
+            Ok(n) => info!("USB PD RX: {=[u8]:?}", &buf[..n]),
+            Err(e) => error!("USB PD RX: {}", e),
+        }
+    }
+}