Fix up all the newly imported Teensy code

Change-Id: Id051083a16336617add1d5f16fc7b7d78a30a5fe
diff --git a/motors/usb/usb_serial.h b/motors/usb/usb_serial.h
index 8367f05..2512adc 100644
--- a/motors/usb/usb_serial.h
+++ b/motors/usb/usb_serial.h
@@ -31,142 +31,48 @@
 #ifndef USBserial_h_
 #define USBserial_h_
 
-#include "usb_desc.h"
-
-#if (defined(CDC_STATUS_INTERFACE) && defined(CDC_DATA_INTERFACE)) || defined(USB_DISABLED)
+#include "motors/usb/usb_desc.h"
 
 #include <inttypes.h>
 
-#if F_CPU >= 20000000 && !defined(USB_DISABLED)
-
 // C language implementation
 #ifdef __cplusplus
 extern "C" {
 #endif
-int usb_serial_getchar(void);
-int usb_serial_peekchar(void);
-int usb_serial_available(void);
-int usb_serial_read(void *buffer, uint32_t size);
-void usb_serial_flush_input(void);
-int usb_serial_putchar(uint8_t c);
-int usb_serial_write(const void *buffer, uint32_t size);
-int usb_serial_write_buffer_free(void);
-void usb_serial_flush_output(void);
-extern uint32_t usb_cdc_line_coding[2];
-extern volatile uint32_t usb_cdc_line_rtsdtr_millis;
-extern volatile uint32_t systick_millis_count;
-extern volatile uint8_t usb_cdc_line_rtsdtr;
-extern volatile uint8_t usb_cdc_transmit_flush_timer;
-extern volatile uint8_t usb_configuration;
+
+void usb_serial_init(void);
+
+// Reads the next character (if any) and returns it. Returns -1 if no characters
+// are available.
+int usb_serial_getchar(int port);
+
+// Returns the next character (if any) or -1.
+int usb_serial_peekchar(int port);
+
+// Reads as many bytes (up to size) as are available now. Returns 0 immediately
+// if no bytes are available. Returns the number of bytes read.
+int usb_serial_read(int port, void *buffer, uint32_t size);
+
+// Drops any unread input until the most recent packet sent.
+void usb_serial_flush_input(int port);
+
+// Writes data. Returns -1 if it times out or size if it succeeds.
+//
+// NOTE: This does not send immediately. The data is buffered
+int usb_serial_write(int port, const void *buffer, uint32_t size);
+
+// Writes a single character. Returns -1 if it times out or 1 if it succeeds.
+static inline int usb_serial_putchar(int port, uint8_t c) {
+  return usb_serial_write(port, &c, 1);
+}
+
+// Immediately flushes all written data.
+//
+// TODO(Brian): What exactly are the semantics here?
+void usb_serial_flush_output(int port);
+
 #ifdef __cplusplus
 }
 #endif
 
-#define USB_SERIAL_DTR  0x01
-#define USB_SERIAL_RTS  0x02
-
-// C++ interface
-#ifdef __cplusplus
-#include "Stream.h"
-class usb_serial_class : public Stream
-{
-public:
-	constexpr usb_serial_class() {}
-        void begin(long) {
-		uint32_t millis_begin = systick_millis_count;
-		while (!(*this)) {
-			// wait up to 2.5 seconds for Arduino Serial Monitor
-			// Yes, this is a long time, but some Windows systems open
-			// the port very slowly.  This wait allows programs for
-			// Arduino Uno to "just work" (without forcing a reboot when
-			// the port is opened), and when no PC is connected the user's
-			// sketch still gets to run normally after this wait time.
-			if ((uint32_t)(systick_millis_count - millis_begin) > 2500) break;
-		}
-	}
-        void end() { /* TODO: flush output and shut down USB port */ };
-        virtual int available() { return usb_serial_available(); }
-        virtual int read() { return usb_serial_getchar(); }
-        virtual int peek() { return usb_serial_peekchar(); }
-        virtual void flush() { usb_serial_flush_output(); }  // TODO: actually wait for data to leave USB...
-        virtual void clear(void) { usb_serial_flush_input(); }
-        virtual size_t write(uint8_t c) { return usb_serial_putchar(c); }
-        virtual size_t write(const uint8_t *buffer, size_t size) { return usb_serial_write(buffer, size); }
-	size_t write(unsigned long n) { return write((uint8_t)n); }
-	size_t write(long n) { return write((uint8_t)n); }
-	size_t write(unsigned int n) { return write((uint8_t)n); }
-	size_t write(int n) { return write((uint8_t)n); }
-	virtual int availableForWrite() { return usb_serial_write_buffer_free(); }
-	using Print::write;
-        void send_now(void) { usb_serial_flush_output(); }
-        uint32_t baud(void) { return usb_cdc_line_coding[0]; }
-        uint8_t stopbits(void) { uint8_t b = usb_cdc_line_coding[1]; if (!b) b = 1; return b; }
-        uint8_t paritytype(void) { return usb_cdc_line_coding[1] >> 8; } // 0=none, 1=odd, 2=even
-        uint8_t numbits(void) { return usb_cdc_line_coding[1] >> 16; }
-        uint8_t dtr(void) { return (usb_cdc_line_rtsdtr & USB_SERIAL_DTR) ? 1 : 0; }
-        uint8_t rts(void) { return (usb_cdc_line_rtsdtr & USB_SERIAL_RTS) ? 1 : 0; }
-        operator bool() { return usb_configuration &&
-		(usb_cdc_line_rtsdtr & (USB_SERIAL_DTR | USB_SERIAL_RTS)) &&
-		((uint32_t)(systick_millis_count - usb_cdc_line_rtsdtr_millis) >= 25);
-	}
-	size_t readBytes(char *buffer, size_t length) {
-		size_t count=0;
-		unsigned long startMillis = millis();
-		do {
-			count += usb_serial_read(buffer + count, length - count);
-			if (count >= length) return count;
-		} while(millis() - startMillis < _timeout);
-		setReadError();
-		return count;
-	}
-
-};
-extern usb_serial_class Serial;
-extern void serialEvent(void);
-#endif // __cplusplus
-
-
-#else  // F_CPU < 20000000
-
-// Allow Arduino programs using Serial to compile, but Serial will do nothing.
-#ifdef __cplusplus
-#include "Stream.h"
-class usb_serial_class : public Stream
-{
-public:
-	constexpr usb_serial_class() {}
-        void begin(long) { };
-        void end() { };
-        virtual int available() { return 0; }
-        virtual int read() { return -1; }
-        virtual int peek() { return -1; }
-        virtual void flush() { }
-        virtual void clear() { }
-        virtual size_t write(uint8_t c) { return 1; }
-        virtual size_t write(const uint8_t *buffer, size_t size) { return size; }
-	size_t write(unsigned long n) { return 1; }
-	size_t write(long n) { return 1; }
-	size_t write(unsigned int n) { return 1; }
-	size_t write(int n) { return 1; }
-	int availableForWrite() { return 0; }
-	using Print::write;
-        void send_now(void) { }
-        uint32_t baud(void) { return 0; }
-        uint8_t stopbits(void) { return 1; }
-        uint8_t paritytype(void) { return 0; }
-        uint8_t numbits(void) { return 8; }
-        uint8_t dtr(void) { return 1; }
-        uint8_t rts(void) { return 1; }
-        operator bool() { return true; }
-};
-
-extern usb_serial_class Serial;
-extern void serialEvent(void);
-#endif // __cplusplus
-
-
-#endif // F_CPU
-
-#endif // CDC_STATUS_INTERFACE && CDC_DATA_INTERFACE
-
 #endif // USBserial_h_