Add option USB CDC to be used for Serial (starting USB early)

cores/esp32/USBCDC.h

@@ -0,0 +1,133 @@
+// Copyright 2015-2020 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#pragma once
+
+#include <inttypes.h>
+
+#include "Stream.h"
+#include "esp32-hal.h"
+#if CONFIG_USB_CDC_ENABLED
+
+#include "esp_event.h"
+
+ESP_EVENT_DECLARE_BASE(ARDUINO_USB_CDC_EVENTS);
+
+typedef enum {
+    ARDUINO_USB_CDC_ANY_EVENT = ESP_EVENT_ANY_ID,
+    ARDUINO_USB_CDC_CONNECTED_EVENT = 0,
+    ARDUINO_USB_CDC_DISCONNECTED_EVENT,
+    ARDUINO_USB_CDC_LINE_STATE_EVENT,
+    ARDUINO_USB_CDC_LINE_CODING_EVENT,
+    ARDUINO_USB_CDC_RX_EVENT,
+    ARDUINO_USB_CDC_MAX_EVENT,
+} arduino_usb_cdc_event_t;
+
+typedef union {
+    struct {
+            bool dtr;
+            bool rts;
+    } line_state;
+    struct {
+            uint32_t bit_rate;
+            uint8_t  stop_bits; ///< 0: 1 stop bit - 1: 1.5 stop bits - 2: 2 stop bits
+            uint8_t  parity;    ///< 0: None - 1: Odd - 2: Even - 3: Mark - 4: Space
+            uint8_t  data_bits; ///< can be 5, 6, 7, 8 or 16
+    } line_coding;
+    struct {
+            size_t len;
+    } rx;
+} arduino_usb_cdc_event_data_t;
+
+class USBCDC: public Stream
+{
+public:
+    USBCDC(uint8_t itf=0);
+
+    void onEvent(esp_event_handler_t callback);
+    void onEvent(arduino_usb_cdc_event_t event, esp_event_handler_t callback);
+
+    size_t setRxBufferSize(size_t);
+    void begin(unsigned long baud=0);
+    void end();
+    
+    int available(void);
+    int availableForWrite(void);
+    int peek(void);
+    int read(void);
+    size_t read(uint8_t *buffer, size_t size);
+    size_t write(uint8_t);
+    size_t write(const uint8_t *buffer, size_t size);
+    void flush(void);
+    
+    inline size_t read(char * buffer, size_t size)
+    {
+        return read((uint8_t*) buffer, size);
+    }
+    inline size_t write(const char * buffer, size_t size)
+    {
+        return write((uint8_t*) buffer, size);
+    }
+    inline size_t write(const char * s)
+    {
+        return write((uint8_t*) s, strlen(s));
+    }
+    inline size_t write(unsigned long n)
+    {
+        return write((uint8_t) n);
+    }
+    inline size_t write(long n)
+    {
+        return write((uint8_t) n);
+    }
+    inline size_t write(unsigned int n)
+    {
+        return write((uint8_t) n);
+    }
+    inline size_t write(int n)
+    {
+        return write((uint8_t) n);
+    }
+    uint32_t baudRate();
+    void setDebugOutput(bool);
+    operator bool() const;
+
+    void enableReboot(bool enable);
+    bool rebootEnabled(void);
+
+    //internal methods
+    void _onDFU(void);
+    void _onLineState(bool _dtr, bool _rts);
+    void _onLineCoding(uint32_t _bit_rate, uint8_t _stop_bits, uint8_t _parity, uint8_t _data_bits);
+    void _onRX(void);
+    void _onUnplugged(void);
+    
+protected:
+    uint8_t  itf;
+    uint32_t bit_rate;
+    uint8_t  stop_bits; ///< 0: 1 stop bit - 1: 1.5 stop bits - 2: 2 stop bits
+    uint8_t  parity;    ///< 0: None - 1: Odd - 2: Even - 3: Mark - 4: Space
+    uint8_t  data_bits; ///< can be 5, 6, 7, 8 or 16
+    bool     dtr;
+    bool     rts;
+    bool     connected;
+    bool     reboot_enable;
+    xQueueHandle rx_queue;
+    
+};
+
+#if ARDUINO_SERIAL_PORT //Serial used for USB CDC
+extern USBCDC Serial;
+#endif
+
+#endif /* CONFIG_USB_CDC_ENABLED */