diff --git a/CHANGELOG.md b/CHANGELOG.md
index 547c2b9..4ab9990 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
## [Unreleased]
+### Added
+
+- Implement `embedded_hal::digital::blocking::IoPin` for `CdevPin` and `SysfsPin`
+
## [v0.4.0-alpha.1] - 2021-09-27
### Changed
diff --git a/src/cdev_pin.rs b/src/cdev_pin.rs
index 5a11fe1..9d91a95 100644
--- a/src/cdev_pin.rs
+++ b/src/cdev_pin.rs
@@ -5,7 +5,7 @@
/// Newtype around [`gpio_cdev::LineHandle`] that implements the `embedded-hal` traits
///
/// [`gpio_cdev::LineHandle`]: https://docs.rs/gpio-cdev/0.5.0/gpio_cdev/struct.LineHandle.html
-pub struct CdevPin(pub gpio_cdev::LineHandle, bool);
+pub struct CdevPin(pub gpio_cdev::LineHandle, gpio_cdev::LineInfo);
impl CdevPin {
/// See [`gpio_cdev::Line::request`][0] for details.
@@ -13,7 +13,43 @@ impl CdevPin {
/// [0]: https://docs.rs/gpio-cdev/0.5.0/gpio_cdev/struct.Line.html#method.request
pub fn new(handle: gpio_cdev::LineHandle) -> Result<Self, gpio_cdev::errors::Error> {
let info = handle.line().info()?;
- Ok(CdevPin(handle, info.is_active_low()))
+ Ok(CdevPin(handle, info))
+ }
+
+ fn get_input_flags(&self) -> gpio_cdev::LineRequestFlags {
+ if self.1.is_active_low() {
+ return gpio_cdev::LineRequestFlags::INPUT | gpio_cdev::LineRequestFlags::ACTIVE_LOW;
+ }
+ gpio_cdev::LineRequestFlags::INPUT
+ }
+
+ fn get_output_flags(&self) -> gpio_cdev::LineRequestFlags {
+ let mut flags = gpio_cdev::LineRequestFlags::OUTPUT;
+ if self.1.is_active_low() {
+ flags.insert(gpio_cdev::LineRequestFlags::ACTIVE_LOW);
+ }
+ if self.1.is_open_drain() {
+ flags.insert(gpio_cdev::LineRequestFlags::OPEN_DRAIN);
+ } else if self.1.is_open_source() {
+ flags.insert(gpio_cdev::LineRequestFlags::OPEN_SOURCE);
+ }
+ return flags;
+ }
+}
+
+/// Converts a pin state to the gpio_cdev compatible numeric value, accounting
+/// for the active_low condition.
+fn state_to_value(state: embedded_hal::digital::PinState, is_active_low: bool) -> u8 {
+ if is_active_low {
+ match state {
+ embedded_hal::digital::PinState::High => 0,
+ embedded_hal::digital::PinState::Low => 1,
+ }
+ } else {
+ match state {
+ embedded_hal::digital::PinState::High => 1,
+ embedded_hal::digital::PinState::Low => 0,
+ }
}
}
@@ -21,19 +57,17 @@ impl embedded_hal::digital::blocking::OutputPin for CdevPin {
type Error = gpio_cdev::errors::Error;
fn set_low(&mut self) -> Result<(), Self::Error> {
- if self.1 {
- self.0.set_value(1)
- } else {
- self.0.set_value(0)
- }
+ self.0.set_value(state_to_value(
+ embedded_hal::digital::PinState::Low,
+ self.1.is_active_low(),
+ ))
}
fn set_high(&mut self) -> Result<(), Self::Error> {
- if self.1 {
- self.0.set_value(0)
- } else {
- self.0.set_value(1)
- }
+ self.0.set_value(state_to_value(
+ embedded_hal::digital::PinState::High,
+ self.1.is_active_low(),
+ ))
}
}
@@ -41,11 +75,12 @@ impl embedded_hal::digital::blocking::InputPin for CdevPin {
type Error = gpio_cdev::errors::Error;
fn is_high(&self) -> Result<bool, Self::Error> {
- if !self.1 {
- self.0.get_value().map(|val| val != 0)
- } else {
- self.0.get_value().map(|val| val == 0)
- }
+ self.0.get_value().map(|val| {
+ val == state_to_value(
+ embedded_hal::digital::PinState::High,
+ self.1.is_active_low(),
+ )
+ })
}
fn is_low(&self) -> Result<bool, Self::Error> {
@@ -53,6 +88,49 @@ impl embedded_hal::digital::blocking::InputPin for CdevPin {
}
}
+impl embedded_hal::digital::blocking::IoPin<CdevPin, CdevPin> for CdevPin {
+ type Error = gpio_cdev::errors::Error;
+
+ fn into_input_pin(self) -> Result<CdevPin, Self::Error> {
+ if self.1.direction() == gpio_cdev::LineDirection::In {
+ return Ok(self);
+ }
+ let line = self.0.line().clone();
+ let input_flags = self.get_input_flags();
+ let consumer = self.1.consumer().unwrap_or("").to_owned();
+
+ // Drop self to free the line before re-requesting it in a new mode.
+ std::mem::drop(self);
+
+ CdevPin::new(line.request(input_flags, 0, &consumer)?)
+ }
+
+ fn into_output_pin(
+ self,
+ state: embedded_hal::digital::PinState,
+ ) -> Result<CdevPin, Self::Error> {
+ if self.1.direction() == gpio_cdev::LineDirection::Out {
+ return Ok(self);
+ }
+
+ let line = self.0.line().clone();
+ let output_flags = self.get_output_flags();
+ let consumer = self.1.consumer().unwrap_or("").to_owned();
+
+ // Drop self to free the line before re-requesting it in a new mode.
+ std::mem::drop(self);
+
+ CdevPin::new(line.request(
+ output_flags,
+ state_to_value(
+ state,
+ output_flags.intersects(gpio_cdev::LineRequestFlags::ACTIVE_LOW),
+ ),
+ &consumer,
+ )?)
+ }
+}
+
impl core::ops::Deref for CdevPin {
type Target = gpio_cdev::LineHandle;
diff --git a/src/sysfs_pin.rs b/src/sysfs_pin.rs
index 3d606ee..f569125 100644
--- a/src/sysfs_pin.rs
+++ b/src/sysfs_pin.rs
@@ -64,6 +64,26 @@ impl embedded_hal::digital::blocking::InputPin for SysfsPin {
}
}
+impl embedded_hal::digital::blocking::IoPin<SysfsPin, SysfsPin> for SysfsPin {
+ type Error = sysfs_gpio::Error;
+
+ fn into_input_pin(self) -> Result<SysfsPin, Self::Error> {
+ self.set_direction(sysfs_gpio::Direction::In)?;
+ Ok(self)
+ }
+
+ fn into_output_pin(
+ self,
+ state: embedded_hal::digital::PinState,
+ ) -> Result<SysfsPin, Self::Error> {
+ self.set_direction(match state {
+ embedded_hal::digital::PinState::High => sysfs_gpio::Direction::High,
+ embedded_hal::digital::PinState::Low => sysfs_gpio::Direction::Low,
+ })?;
+ Ok(self)
+ }
+}
+
impl core::ops::Deref for SysfsPin {
type Target = sysfs_gpio::Pin;