From 35068a34ee322d8c4b921954e9610d3ee7389e0c Mon Sep 17 00:00:00 2001
From: folkert van heusden <mail@vanheusden.com>
Date: Wed, 8 May 2024 09:33:05 +0200
Subject: [PATCH] DC11: I/O to "Stream"-device (serial port on Arduino)

---
 dc11.cpp | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++----
 dc11.h   | 22 ++++++++++-----------
 2 files changed, 66 insertions(+), 15 deletions(-)

diff --git a/dc11.cpp b/dc11.cpp
index 97ad1ff..97b0e79 100644
--- a/dc11.cpp
+++ b/dc11.cpp
@@ -1,6 +1,9 @@
 // (C) 2024 by Folkert van Heusden
 // Released under MIT license
 
+#if defined(ESP32)
+#include <Arduino.h>
+#endif
 #if defined(ESP32)
 #include <lwip/sockets.h>
 #include <arpa/inet.h>
@@ -49,6 +52,13 @@ dc11::~dc11()
 	}
 
 	delete [] pfds;
+
+#if defined(ESP32)
+	if (serial_th) {
+		serial_th->join();
+		delete serial_th;
+	}
+#endif
 }
 
 void dc11::trigger_interrupt(const int line_nr, const bool is_tx)
@@ -63,13 +73,15 @@ void dc11::operator()()
 	DOLOG(info, true, "DC11 thread started");
 
 	for(int i=0; i<dc11_n_lines; i++) {
-#if defined(ESP32)
-		if (i == 3)  // uggly hack
-			break;
-#endif
 		// client session
 		pfds[dc11_n_lines + i].fd     = INVALID_SOCKET;
 		pfds[dc11_n_lines + i].events = POLLIN;
+#if defined(ESP32)
+		if (i == 3) {  // prevent accept() on this socket
+			pfds[i].fd = INVALID_SOCKET;
+			continue;
+		}
+#endif
 
 		// listen on port
 		int port = base_port + i + 1;
@@ -188,6 +200,38 @@ void dc11::operator()()
 	}
 }
 
+#if defined(ESP32)
+void dc11::set_serial(Stream *const s)
+{
+	if (serial_th) {
+		DOLOG(info, true, "DC11: serial port already configured");
+		return;
+	}
+
+	this->s = s;
+
+	serial_th = new std::thread(&dc11::serial_handler, this);
+}
+
+void dc11::serial_handler()
+{
+	while(!stop_flag) {
+		yield();
+
+		if (s->available() == 0)
+			continue;
+
+		// 3 is reserved for a serial port
+		recv_buffers[3].push_back(s->read());
+
+		registers[3 * 4 + 0] |= 128;  // DONE: bit 7
+
+		if (is_rx_interrupt_enabled(3))
+			trigger_interrupt(3, false);
+	}
+}
+#endif
+
 void dc11::reset()
 {
 }
@@ -310,6 +354,13 @@ void dc11::write_word(const uint16_t addr, const uint16_t v)
 		else
 			TRACE("DC11: transmit %c on line %d", c, line_nr);
 
+#if defined(ESP32)
+		if (line_nr == 3) {
+			if (s != nullptr)
+				s->write(c);
+			return;
+		}
+#endif
 		SOCKET fd = pfds[dc11_n_lines + line_nr].fd;
 
 		if (fd != INVALID_SOCKET && write(fd, &c, 1) != 1) {
diff --git a/dc11.h b/dc11.h
index 005e39d..b264351 100644
--- a/dc11.h
+++ b/dc11.h
@@ -2,9 +2,6 @@
 // Released under MIT license
 
 #pragma once
-#if defined(ESP32)
-#include <Arduino.h>
-#endif
 #include <atomic>
 #include <condition_variable>
 #include <cstdint>
@@ -27,6 +24,7 @@
 #define DC11_BASE DC11_RCSR
 #define DC11_END  (DC11_BASE + (4 * 4 + 1) * 2)  // 4 interfaces, + 2 to point behind it
 
+class Stream;
 class bus;
 struct pollfd;
 
@@ -36,22 +34,23 @@ constexpr const int dc11_n_lines = 4;
 class dc11
 {
 private:
-	int              base_port        { 1100    };
-	bus             *const b          { nullptr };
-	uint16_t         registers[4 * dc11_n_lines] { 0 };
-	std::atomic_bool stop_flag        { false   };
-	std::thread     *th               { nullptr };
+	int               base_port        { 1100    };
+	bus              *const b          { nullptr };
+	uint16_t          registers[4 * dc11_n_lines] { 0 };
+	std::atomic_bool  stop_flag        { false   };
+	std::thread      *th               { nullptr };
 
 	// not statically allocated because of compiling problems on arduino
 #if defined(_WIN32)
-	WSAPOLLFD        *pfds            { nullptr };
+	WSAPOLLFD        *pfds             { nullptr };
 #else
-	pollfd           *pfds            { nullptr };
+	pollfd           *pfds             { nullptr };
 #endif
 	std::vector<char> recv_buffers[dc11_n_lines];
         std::mutex        input_lock[dc11_n_lines];
 #if defined(ESP32)
-	Stream           *s               { nullptr };
+	Stream           *s                { nullptr };
+	std::thread      *serial_th        { nullptr };
 #endif
 
 	void trigger_interrupt(const int line_nr, const bool is_tx);
@@ -70,6 +69,7 @@ public:
 	void reset();
 #if defined(ESP32)
 	void set_serial(Stream *const s);
+	void serial_handler();
 #endif
 
 	uint8_t  read_byte(const uint16_t addr);