Add serialEvent support for USB, UART0, UART1

cores/rp2040/SerialUART.cpp

@@ -22,6 +22,14 @@
 #include <hardware/uart.h>
 #include <hardware/gpio.h>
 
+// SerialEvent functions are weak, so when the user doesn't define them,
+// the linker just sets their address to 0 (which is checked below).
+// The Serialx_available is just a wrapper around Serialx.available(),
+// but we can refer to it weakly so we don't pull in the entire
+// HardwareSerial instance if the user doesn't also refer to it.
+extern void serialEvent1() __attribute__((weak));
+extern void serialEvent2() __attribute__((weak));
+
 bool SerialUART::setPinout(pin_size_t tx, pin_size_t rx) {
     const uint32_t uart_tx[2] = { 0b000010001000000000001000100000, 0b100000000000100010000000000010 };
     const uint32_t uart_rx[2] = { 0b000001000100000000000100010000, 0b010000000000010001000000000001 };
@@ -147,3 +155,14 @@ SerialUART::operator bool() {
 SerialUART Serial1(uart0, 0, 1);
 SerialUART Serial2(uart1, 4, 5);
 
+void arduino::serialEvent1Run(void) {
+    if (serialEvent1 && Serial1.available()) {
+      serialEvent1();
+    }
+}
+
+void arduino::serialEvent2Run(void) {
+    if (serialEvent2 && Serial2.available()) {
+      serialEvent2();
+    }
+}

cores/rp2040/SerialUART.h

@@ -81,4 +81,9 @@ private:
 extern SerialUART Serial1; // HW UART 0
 extern SerialUART Serial2; // HW UART 1
 
+namespace arduino {
+    extern void serialEvent1Run(void) __attribute__((weak));
+    extern void serialEvent2Run(void) __attribute__((weak));
+};
+
 #endif

cores/rp2040/SerialUSB.cpp

@@ -22,18 +22,22 @@
 
 #include <Arduino.h>
 
-
 #include "tusb.h"
 #include "pico/time.h"
 #include "pico/binary_info.h"
-extern "C" {
-    #include "pico/bootrom.h"
-}
+#include "pico/bootrom.h"
 #include "hardware/irq.h"
 #include "pico/mutex.h"
 #include "hardware/watchdog.h"
 #include "pico/unique_id.h"
 
+// SerialEvent functions are weak, so when the user doesn't define them,
+// the linker just sets their address to 0 (which is checked below).
+// The Serialx_available is just a wrapper around Serialx.available(),
+// but we can refer to it weakly so we don't pull in the entire
+// HardwareSerial instance if the user doesn't also refer to it.
+extern void serialEvent() __attribute__((weak));
+
 #define PICO_STDIO_USB_TASK_INTERVAL_US 1000
 #define PICO_STDIO_USB_LOW_PRIORITY_IRQ 31
 
@@ -178,6 +182,10 @@ void SerialUSB::end() {
 }
 
 int SerialUSB::peek() {
+    if (!_running) {
+        return 0;
+    }
+
     uint8_t c;
     uint32_t owner;
     if (!mutex_try_enter(&usb_mutex, &owner)) {
@@ -190,6 +198,10 @@ int SerialUSB::peek() {
 }
 
 int SerialUSB::read() {
+    if (!_running) {
+        return -1;
+    }
+
     uint32_t owner;
     if (!mutex_try_enter(&usb_mutex, &owner)) {
         if (owner == get_core_num()) return -1; // would deadlock otherwise
@@ -203,7 +215,12 @@ int SerialUSB::read() {
     mutex_exit(&usb_mutex);
     return -1;
 }
+
 int SerialUSB::available() {
+    if (!_running) {
+        return 0;
+    }
+
     uint32_t owner;
     if (!mutex_try_enter(&usb_mutex, &owner)) {
         if (owner == get_core_num()) return 0; // would deadlock otherwise
@@ -213,7 +230,12 @@ int SerialUSB::available() {
     mutex_exit(&usb_mutex);
     return ret;
 }
+
 int SerialUSB::availableForWrite() {
+    if (!_running) {
+        return 0;
+    }
+
     uint32_t owner;
     if (!mutex_try_enter(&usb_mutex, &owner)) {
         if (owner == get_core_num()) return 0; // would deadlock otherwise
@@ -223,7 +245,12 @@ int SerialUSB::availableForWrite() {
     mutex_exit(&usb_mutex);
     return ret;
 }
+
 void SerialUSB::flush() {
+    if (!_running) {
+        return;
+    }
+
     uint32_t owner;
     if (!mutex_try_enter(&usb_mutex, &owner)) {
         if (owner == get_core_num()) return; // would deadlock otherwise
@@ -232,10 +259,16 @@ void SerialUSB::flush() {
     tud_cdc_write_flush();
     mutex_exit(&usb_mutex);
 }
+
 size_t SerialUSB::write(uint8_t c) {
     return write(&c, 1);
 }
+
 size_t SerialUSB::write(const uint8_t *buf, size_t length) {
+    if (!_running) {
+        return 0;
+    }
+
     static uint64_t last_avail_time;
     uint32_t owner;
     if (!mutex_try_enter(&usb_mutex, &owner)) {
@@ -270,7 +303,12 @@ size_t SerialUSB::write(const uint8_t *buf, size_t length) {
     mutex_exit(&usb_mutex);
     return i;
 }
+
 SerialUSB::operator bool() {
+    if (!_running) {
+        return false;
+    }
+
     uint32_t owner;
     if (!mutex_try_enter(&usb_mutex, &owner)) {
         if (owner == get_core_num()) return -1; // would deadlock otherwise
@@ -304,5 +342,11 @@ extern "C" void tud_cdc_line_coding_cb(uint8_t itf, cdc_line_coding_t const* p_l
     CheckSerialReset();
 }
 
-
 SerialUSB Serial;
+
+void arduino::serialEventRun(void)
+{
+    if (serialEvent && Serial.available()) {
+      serialEvent();
+    }
+}

cores/rp2040/SerialUSB.h

@@ -72,4 +72,8 @@ private:
 
 extern SerialUSB Serial;
 
+namespace arduino {
+    extern void serialEventRun(void) __attribute__((weak));
+};
+
 #endif

cores/rp2040/main.cpp

@@ -28,6 +28,15 @@ extern "C" int main() {
     setup();
     while (1) {
         loop();
+        if (arduino::serialEventRun) {
+            arduino::serialEventRun();
+        }
+        if (arduino::serialEvent1Run) {
+            arduino::serialEvent1Run();
+        }
+        if (arduino::serialEvent2Run) {
+            arduino::serialEvent2Run();
+        }
     }
     return 0;
 }

libraries/EEPROM/EEPROM.cpp

@@ -22,10 +22,7 @@
 
 #include <Arduino.h>
 #include "EEPROM.h"
-extern "C" {
-// This header is missing the "ifdef cplusplus extern C" bit
 #include <hardware/flash.h>
-}
 #include <hardware/sync.h>
 
 extern "C" uint8_t _EEPROM_start;