From 0107d3e6e74d96c4ec35d7bfa2cf091ed353cb9f Mon Sep 17 00:00:00 2001
From: Erki <erki@skullnet.me>
Date: Mon, 24 Feb 2025 18:24:30 +0200
Subject: [PATCH] WIP7: Add async serial IO support

---
 Peripherals/Inc/peripherals_hal_st.hpp       | 113 ++++++++++++++++++-
 coro/inc/skullc/coro/peripheral_awaiters.hpp |  39 +++++++
 2 files changed, 151 insertions(+), 1 deletion(-)

diff --git a/Peripherals/Inc/peripherals_hal_st.hpp b/Peripherals/Inc/peripherals_hal_st.hpp
index 8d3a105..20e369d 100644
--- a/Peripherals/Inc/peripherals_hal_st.hpp
+++ b/Peripherals/Inc/peripherals_hal_st.hpp
@@ -31,7 +31,7 @@ template<typename Origin>
 using IsrCallbackFn = void (*)(Origin*);
 
 template<typename Origin, typename Handler, void (Handler::*func)(),
-         typename Tag>
+         typename Tag = decltype([] {})>
 IsrCallbackFn<Origin> createCallback(Handler& h_in)
 {
   static Handler* h = &h_in;
@@ -200,6 +200,104 @@ struct SerialInterfaceAsync
   }
 };
 
+#ifdef SKULLC_WITH_CORO
+template<typename T,
+         HAL_StatusTypeDef (*transmit_)(T*, std::uint8_t* data,
+                                        std::uint16_t data_len),
+         HAL_StatusTypeDef (*receive_)(T*, std::uint8_t* data,
+                                       std::uint16_t data_len)>
+struct SerialInterfaceCoro
+{
+private:
+  void on_rx_complete()
+  {
+    if (rx_awaiter_)
+      rx_awaiter_->set_completed();
+  }
+
+  void on_tx_complete()
+  {
+    if (tx_awaiter_)
+      tx_awaiter_->set_completed();
+  }
+
+  std::optional<skullc::coro::ISRAwaiter> rx_awaiter_ = std::nullopt;
+  std::optional<skullc::coro::ISRAwaiter> tx_awaiter_ = std::nullopt;
+
+public:
+  using underlying_handle_type = T;
+  underlying_handle_type* handle;
+
+  SerialInterfaceCoro() = delete;
+
+  template<typename = decltype([] {})>
+  explicit SerialInterfaceCoro(underlying_handle_type* handle)
+      : handle(handle)
+  {
+    handle->RxCpltCallback = createCallback<T,
+                                            std::decay_t<decltype(*this)>,
+                                            &std::decay_t<decltype(*this)>::on_rx_complete>(*this);
+
+    handle->TxCpltCallback = createCallback<T,
+                                            std::decay_t<decltype(*this)>,
+                                            &std::decay_t<decltype(*this)>::on_tx_complete>(*this);
+  }
+
+  skullc::coro::Task<bool> transmit(std::uint8_t* data, const std::uint32_t data_len)
+  {
+    tx_awaiter_.emplace();
+    const auto status = transmit_(handle, data, data_len);
+    if (status != HAL_StatusTypeDef::HAL_OK)
+      co_return false;
+
+    co_await *tx_awaiter_;
+    tx_awaiter_ = std::nullopt;
+
+    co_return true;
+  }
+
+  template<typename Td, std::size_t N>
+  skullc::coro::Task<bool> transmit(std::array<Td, N>& array)
+  {
+    static_assert(sizeof(Td) == sizeof(std::uint8_t), "Data is not a byte large.");
+
+    return transmit(reinterpret_cast<std::uint8_t*>(array.data()), std::uint32_t(N));
+  }
+
+  skullc::coro::Task<bool> receive(std::uint8_t* data, const std::uint32_t data_len)
+  {
+    rx_awaiter_.emplace();
+    const auto status = receive_(handle, data, data_len);
+    if (status != HAL_StatusTypeDef::HAL_OK)
+      co_return false;
+
+    co_await *rx_awaiter_;
+    rx_awaiter_ = std::nullopt;
+
+    co_return true;
+  }
+
+  template<typename Td, std::size_t N>
+  skullc::coro::Task<bool> receive(std::array<Td, N>& array)
+  {
+    static_assert(sizeof(Td) == sizeof(std::uint8_t), "Data is not a byte large.");
+
+    return receive(reinterpret_cast<std::uint8_t*>(array.data()), std::uint32_t(N));
+  }
+
+  template<std::size_t N>
+  skullc::coro::Task<std::array<std::uint8_t, N>> receive()
+  {
+    std::array<std::uint8_t, N> data;
+    data.fill(0);
+
+    co_await receive(data.data(), std::uint32_t(N));
+
+    co_return data;
+  }
+};
+#endif// SKULLC_WITH_CORO
+
 #ifdef HAL_SPI_MODULE_ENABLED
 
 using SpiInterface =
@@ -296,6 +394,11 @@ inline HAL_StatusTypeDef uartTransmitDma(UART_HandleTypeDef* huart, std::uint8_t
   return HAL_UART_Transmit_DMA(huart, data, size);
 }
 
+inline HAL_StatusTypeDef uartTransmitIt(UART_HandleTypeDef* huart, std::uint8_t* data, const std::uint16_t size)
+{
+  return HAL_UART_Transmit_IT(huart, data, size);
+}
+
 }// namespace _Details
 
 using UartInterface =
@@ -303,6 +406,14 @@ using UartInterface =
 using UartInterfaceDMA =
         SerialInterfaceAsync<UART_HandleTypeDef, _Details::uartTransmitDma,
                              HAL_UART_Receive_DMA>;
+#ifdef SKULLC_WITH_CORO
+using UartInterfaceCoro =
+        SerialInterfaceCoro<UART_HandleTypeDef, _Details::uartTransmitIt,
+                            HAL_UART_Receive_IT>;
+using UartInterfaceCoroDma =
+        SerialInterfaceCoro<UART_HandleTypeDef, _Details::uartTransmitDma,
+                            HAL_UART_Receive_DMA>;
+#endif// SKULLC_WITH_CORO
 
 #endif// HAL_UART_MODULE_ENABLED
 
diff --git a/coro/inc/skullc/coro/peripheral_awaiters.hpp b/coro/inc/skullc/coro/peripheral_awaiters.hpp
index f505d01..f5b7d3f 100644
--- a/coro/inc/skullc/coro/peripheral_awaiters.hpp
+++ b/coro/inc/skullc/coro/peripheral_awaiters.hpp
@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <atomic>
 #include <coroutine>
 #include <optional>
 
@@ -78,4 +79,42 @@ private:
   }
 };
 
+struct ISRAwaiter
+{
+  ISRAwaiter() = default;
+
+  ~ISRAwaiter()
+  {
+    if (continuation)
+      this_coro::scheduler().remove(continuation);
+  }
+
+  bool await_ready()
+  {
+    return isr_completed;
+  }
+
+  void await_suspend(std::coroutine_handle<> h)
+  {
+    continuation = h;
+    suspended = true;
+  }
+
+  auto await_resume()
+  {
+    continuation = {};
+  }
+
+  void set_completed()
+  {
+    isr_completed = true;
+    if (suspended == true)
+      this_coro::scheduler().schedule(continuation, 0);
+  }
+
+  std::coroutine_handle<> continuation;
+  std::atomic<bool> isr_completed = false;
+  std::atomic<bool> suspended = false;
+};
+
 }// namespace skullc::coro