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| 1 | +//! # Digital I/O |
| 2 | +//! # Note |
| 3 | +//! |
| 4 | +//! Implementation of the Async Embedded HAL I/O functionality. |
| 5 | +//! |
| 6 | +
|
| 7 | +macro_rules! gpio_async { |
| 8 | + ($GPIOX:ident, [ |
| 9 | + $($PXi:ident: ($pxi:ident, $i:expr, $handle:ident),)+ |
| 10 | + ]) => { |
| 11 | + use core::cell::RefCell; |
| 12 | + use core::task::{Poll, Waker}; |
| 13 | + use core::future::poll_fn; |
| 14 | + use critical_section::Mutex; |
| 15 | + use crate::gpio::*; |
| 16 | + use crate::gpio::gpio0::*; |
| 17 | + use e310x::$GPIOX; |
| 18 | + use e310x::interrupt::ExternalInterrupt; |
| 19 | + use embedded_hal::digital::{Error, ErrorKind, ErrorType, InputPin}; |
| 20 | + use embedded_hal_async::digital::Wait; |
| 21 | + |
| 22 | + /// Error type for wait trait. |
| 23 | + #[derive(Debug, Clone, Copy, PartialEq, Eq)] |
| 24 | + pub enum DigitalError { |
| 25 | + /// Error indicating that a wait operation was already in progress. |
| 26 | + AlreadyWaiting, |
| 27 | + /// Other errors. |
| 28 | + Other, |
| 29 | + } |
| 30 | + |
| 31 | + const N_PINS: usize = 32; |
| 32 | + static PIN_WAKERS: Mutex<RefCell<[Option<Waker>; N_PINS]>> = |
| 33 | + Mutex::new(RefCell::new([const{None}; N_PINS])); |
| 34 | + |
| 35 | + impl Error for DigitalError { |
| 36 | + fn kind(&self) -> ErrorKind { |
| 37 | + ErrorKind::Other |
| 38 | + } |
| 39 | + } |
| 40 | + |
| 41 | + /// Interrupt handler for GPIO pins. |
| 42 | + #[inline] |
| 43 | + fn on_irq(pin_n: usize) { |
| 44 | + let gpio_block = unsafe { $GPIOX::steal() }; |
| 45 | + let pin_mask = 1 << pin_n; |
| 46 | + |
| 47 | + // Disable the interrupt for the pin |
| 48 | + unsafe{ |
| 49 | + gpio_block.high_ie().modify(|r, w| w.bits(r.bits() &! pin_mask)); |
| 50 | + gpio_block.low_ie().modify(|r, w| w.bits(r.bits() &! pin_mask)); |
| 51 | + gpio_block.rise_ie().modify(|r, w| w.bits(r.bits() &! pin_mask)); |
| 52 | + gpio_block.fall_ie().modify(|r, w| w.bits(r.bits() &! pin_mask)); |
| 53 | + } |
| 54 | + |
| 55 | + // Wake the pin if possible |
| 56 | + critical_section::with(|cs| { |
| 57 | + let mut pin_wakers = PIN_WAKERS.borrow_ref_mut(cs); |
| 58 | + if let Some(pinwaker) = pin_wakers[pin_n].take() { |
| 59 | + pinwaker.wake(); |
| 60 | + } |
| 61 | + }); |
| 62 | + |
| 63 | + // Clear pending pin interrupts |
| 64 | + unsafe{ |
| 65 | + gpio_block.high_ip().write(|w| w.bits(pin_mask)); |
| 66 | + gpio_block.low_ip().write(|w| w.bits(pin_mask)); |
| 67 | + gpio_block.rise_ip().write(|w| w.bits(pin_mask)); |
| 68 | + gpio_block.fall_ip().write(|w| w.bits(pin_mask)); |
| 69 | + } |
| 70 | + } |
| 71 | + |
| 72 | + /// GPIO |
| 73 | + $( |
| 74 | + impl<MODE> ErrorType for $PXi<Input<MODE>> { |
| 75 | + type Error = DigitalError; |
| 76 | + } |
| 77 | + /// Wait trait implementation |
| 78 | + impl<MODE> Wait for $PXi<Input<MODE>> { |
| 79 | + #[inline] |
| 80 | + async fn wait_for_high(&mut self) -> Result<(), Self::Error> { |
| 81 | + // If the pin is already high, no need to wait. |
| 82 | + if self.is_high().unwrap() { |
| 83 | + return Ok(()); |
| 84 | + } |
| 85 | + |
| 86 | + // Prevent concurrent waiters. |
| 87 | + if critical_section::with(|cs| { |
| 88 | + PIN_WAKERS.borrow_ref(cs)[$i].is_some() |
| 89 | + }){ |
| 90 | + return Err(DigitalError::AlreadyWaiting); |
| 91 | + } |
| 92 | + |
| 93 | + // Clear previous high interrupts for the pin. |
| 94 | + self.clear_interrupt(EventType::High); |
| 95 | + |
| 96 | + // Enable the high interrupt for the pin. |
| 97 | + self.enable_interrupt(EventType::High); |
| 98 | + |
| 99 | + // Await until an interrupt indicates that the pin has transitioned high. |
| 100 | + poll_fn(|cx| { |
| 101 | + if !self.is_interrupt_enabled(EventType::High) { |
| 102 | + Poll::Ready(Ok(())) |
| 103 | + } else { |
| 104 | + critical_section::with(|cs| { |
| 105 | + let mut pinwaker = PIN_WAKERS.borrow_ref_mut(cs); |
| 106 | + pinwaker[$i] = Some(cx.waker().clone()); |
| 107 | + }); |
| 108 | + Poll::Pending |
| 109 | + } |
| 110 | + }).await |
| 111 | + } |
| 112 | + |
| 113 | + #[inline] |
| 114 | + async fn wait_for_low(&mut self) -> Result<(), Self::Error> { |
| 115 | + // If the pin is already low, no need to wait. |
| 116 | + if self.is_low().unwrap() { |
| 117 | + return Ok(()); |
| 118 | + } |
| 119 | + |
| 120 | + // Prevent concurrent waiters. |
| 121 | + if critical_section::with(|cs| { |
| 122 | + PIN_WAKERS.borrow_ref(cs)[$i].is_some() |
| 123 | + }){ |
| 124 | + return Err(DigitalError::AlreadyWaiting); |
| 125 | + } |
| 126 | + |
| 127 | + // Clear previous low interrupts for the pin. |
| 128 | + self.clear_interrupt(EventType::Low); |
| 129 | + |
| 130 | + // Enable the low interrupt for the pin. |
| 131 | + self.enable_interrupt(EventType::Low); |
| 132 | + |
| 133 | + // Await until an interrupt indicates that the pin has transitioned high. |
| 134 | + poll_fn(|cx| { |
| 135 | + if !self.is_interrupt_enabled(EventType::Low) { |
| 136 | + Poll::Ready(Ok(())) |
| 137 | + } else { |
| 138 | + critical_section::with(|cs| { |
| 139 | + let mut pinwaker = PIN_WAKERS.borrow_ref_mut(cs); |
| 140 | + pinwaker[$i] = Some(cx.waker().clone()); |
| 141 | + }); |
| 142 | + Poll::Pending |
| 143 | + } |
| 144 | + }).await |
| 145 | + } |
| 146 | + |
| 147 | + #[inline] |
| 148 | + async fn wait_for_rising_edge(&mut self) -> Result<(), Self::Error> { |
| 149 | + // Prevent concurrent waiters. |
| 150 | + if critical_section::with(|cs| { |
| 151 | + PIN_WAKERS.borrow_ref(cs)[$i].is_some() |
| 152 | + }){ |
| 153 | + return Err(DigitalError::AlreadyWaiting); |
| 154 | + } |
| 155 | + |
| 156 | + // Clear previous rising edge interrupts for the pin. |
| 157 | + self.clear_interrupt(EventType::Rise); |
| 158 | + |
| 159 | + // Enable the rising edge interrupt for the pin. |
| 160 | + self.enable_interrupt(EventType::Rise); |
| 161 | + |
| 162 | + // Await until an interrupt indicates that the pin has transitioned high. |
| 163 | + poll_fn(|cx| { |
| 164 | + if !self.is_interrupt_enabled(EventType::Rise) { |
| 165 | + Poll::Ready(Ok(())) |
| 166 | + } else { |
| 167 | + critical_section::with(|cs| { |
| 168 | + let mut pinwaker = PIN_WAKERS.borrow_ref_mut(cs); |
| 169 | + pinwaker[$i] = Some(cx.waker().clone()); |
| 170 | + }); |
| 171 | + Poll::Pending |
| 172 | + } |
| 173 | + }).await |
| 174 | + } |
| 175 | + |
| 176 | + #[inline] |
| 177 | + async fn wait_for_falling_edge(&mut self) -> Result<(), Self::Error> { |
| 178 | + // Prevent concurrent waiters. |
| 179 | + if critical_section::with(|cs| { |
| 180 | + PIN_WAKERS.borrow_ref(cs)[$i].is_some() |
| 181 | + }){ |
| 182 | + return Err(DigitalError::AlreadyWaiting); |
| 183 | + } |
| 184 | + |
| 185 | + // Clear previous falling edge interrupts for the pin. |
| 186 | + self.clear_interrupt(EventType::Fall); |
| 187 | + |
| 188 | + // Enable the falling edge interrupt for the pin. |
| 189 | + self.enable_interrupt(EventType::Fall); |
| 190 | + |
| 191 | + // Await until an interrupt indicates that the pin has transitioned high. |
| 192 | + poll_fn(|cx| { |
| 193 | + if !self.is_interrupt_enabled(EventType::Fall) { |
| 194 | + Poll::Ready(Ok(())) |
| 195 | + } else { |
| 196 | + critical_section::with(|cs| { |
| 197 | + let mut pinwaker = PIN_WAKERS.borrow_ref_mut(cs); |
| 198 | + pinwaker[$i] = Some(cx.waker().clone()); |
| 199 | + }); |
| 200 | + Poll::Pending |
| 201 | + } |
| 202 | + }).await |
| 203 | + } |
| 204 | + |
| 205 | + #[inline] |
| 206 | + async fn wait_for_any_edge(&mut self) -> Result<(), Self::Error> { |
| 207 | + // Prevent concurrent waiters. |
| 208 | + if critical_section::with(|cs| { |
| 209 | + PIN_WAKERS.borrow_ref(cs)[$i].is_some() |
| 210 | + }){ |
| 211 | + return Err(DigitalError::AlreadyWaiting); |
| 212 | + } |
| 213 | + |
| 214 | + // Clear previous rising and falling edge interrupts for the pin. |
| 215 | + self.clear_interrupt(EventType::BothEdges); |
| 216 | + |
| 217 | + // Enable the rising and falling edge interrupts for the pin. |
| 218 | + self.enable_interrupt(EventType::BothEdges); |
| 219 | + |
| 220 | + // Await until an interrupt indicates that the pin has transitioned high. |
| 221 | + poll_fn(|cx| { |
| 222 | + if !self.is_interrupt_enabled(EventType::BothEdges) { |
| 223 | + Poll::Ready(Ok(())) |
| 224 | + } else { |
| 225 | + critical_section::with(|cs| { |
| 226 | + let mut pinwaker = PIN_WAKERS.borrow_ref_mut(cs); |
| 227 | + pinwaker[$i] = Some(cx.waker().clone()); |
| 228 | + }); |
| 229 | + Poll::Pending |
| 230 | + } |
| 231 | + }).await |
| 232 | + } |
| 233 | + } |
| 234 | + |
| 235 | + /// Pin Interrupt Handler |
| 236 | + #[riscv_rt::external_interrupt(ExternalInterrupt::$handle)] |
| 237 | + fn $pxi() { |
| 238 | + on_irq($i); |
| 239 | + } |
| 240 | + )+ |
| 241 | + } |
| 242 | +} |
| 243 | + |
| 244 | +gpio_async!(Gpio0, [ |
| 245 | + Pin0: (pin0, 0, GPIO0), |
| 246 | + Pin1: (pin1, 1, GPIO1), |
| 247 | + Pin2: (pin2, 2, GPIO2), |
| 248 | + Pin3: (pin3, 3, GPIO3), |
| 249 | + Pin4: (pin4, 4, GPIO4), |
| 250 | + Pin5: (pin5, 5, GPIO5), |
| 251 | + Pin6: (pin6, 6, GPIO6), |
| 252 | + Pin7: (pin7, 7, GPIO7), |
| 253 | + Pin8: (pin8, 8, GPIO8), |
| 254 | + Pin9: (pin9, 9, GPIO9), |
| 255 | + Pin10: (pin10, 10, GPIO10), |
| 256 | + Pin11: (pin11, 11, GPIO11), |
| 257 | + Pin12: (pin12, 12, GPIO12), |
| 258 | + Pin13: (pin13, 13, GPIO13), |
| 259 | + Pin14: (pin14, 14, GPIO14), |
| 260 | + Pin15: (pin15, 15, GPIO15), |
| 261 | + Pin16: (pin16, 16, GPIO16), |
| 262 | + Pin17: (pin17, 17, GPIO17), |
| 263 | + Pin18: (pin18, 18, GPIO18), |
| 264 | + Pin19: (pin19, 19, GPIO19), |
| 265 | + Pin20: (pin20, 20, GPIO20), |
| 266 | + Pin21: (pin21, 21, GPIO21), |
| 267 | + Pin22: (pin22, 22, GPIO22), |
| 268 | + Pin23: (pin23, 23, GPIO23), |
| 269 | + Pin24: (pin24, 24, GPIO24), |
| 270 | + Pin25: (pin25, 25, GPIO25), |
| 271 | + Pin26: (pin26, 26, GPIO26), |
| 272 | + Pin27: (pin27, 27, GPIO27), |
| 273 | + Pin28: (pin28, 28, GPIO28), |
| 274 | + Pin29: (pin29, 29, GPIO29), |
| 275 | + Pin30: (pin30, 30, GPIO30), |
| 276 | + Pin31: (pin31, 31, GPIO31), |
| 277 | +]); |
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