initial work on mct8316a

flight/src/hardware/raspi/pwm.rs

@@ -0,0 +1,55 @@
+use std::fmt::{Display, Formatter};
+use std::time::Duration;
+use embedded_hal::pwm::{ErrorKind, ErrorType, SetDutyCycle};
+use log::trace;
+use rpi_pal::pwm::Pwm;
+
+const PWM_PERIOD: Duration = Duration::from_micros(1000); // 1kHz
+
+pub struct PwmWrapper {
+    pwm: Pwm
+}
+
+impl PwmWrapper {
+    pub fn new(pwm: Pwm) -> anyhow::Result<Self> {
+        trace!("PwmWrapper::new(pwm: {pwm:?})");
+        pwm.set_period(PWM_PERIOD)?;
+        pwm.enable()?;
+        Ok(Self {
+            pwm
+        })
+    }
+}
+
+#[derive(Debug)]
+pub struct ErrorWrapper(rpi_pal::pwm::Error);
+
+impl embedded_hal::pwm::Error for ErrorWrapper {
+    fn kind(&self) -> ErrorKind {
+        ErrorKind::Other
+    }
+}
+
+impl Display for ErrorWrapper {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+impl std::error::Error for ErrorWrapper {}
+
+impl ErrorType for PwmWrapper {
+    type Error = ErrorWrapper;
+}
+
+impl SetDutyCycle for PwmWrapper {
+    fn max_duty_cycle(&self) -> u16 {
+        trace!("PwmWrapper::max_duty_cycle()");
+        u16::MAX
+    }
+
+    fn set_duty_cycle(&mut self, duty: u16) -> Result<(), Self::Error> {
+        trace!("PwmWrapper::set_duty_cycle(duty: {duty})");
+        self.pwm.set_duty_cycle((duty as f64) / (u16::MAX as f64)).map_err(ErrorWrapper)
+    }
+}