Add more const-ness to the stream endpoint/pipe functions where possible.
[pub/USBasp.git] / LUFA / Drivers / Peripheral / Serial.h
index 23bbd6a..e7c2fa0 100644 (file)
@@ -1,21 +1,21 @@
 /*
              LUFA Library
-     Copyright (C) Dean Camera, 2010.
-              
+     Copyright (C) Dean Camera, 2011.
+
   dean [at] fourwalledcubicle [dot] com
-      www.fourwalledcubicle.com
+           www.lufa-lib.org
 */
 
 /*
-  Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)
+  Copyright 2011  Dean Camera (dean [at] fourwalledcubicle [dot] com)
 
-  Permission to use, copy, modify, distribute, and sell this 
+  Permission to use, copy, modify, distribute, and sell this
   software and its documentation for any purpose is hereby granted
-  without fee, provided that the above copyright notice appear in 
+  without fee, provided that the above copyright notice appear in
   all copies and that both that the copyright notice and this
-  permission notice and warranty disclaimer appear in supporting 
-  documentation, and that the name of the author not be used in 
-  advertising or publicity pertaining to distribution of the 
+  permission notice and warranty disclaimer appear in supporting
+  documentation, and that the name of the author not be used in
+  advertising or publicity pertaining to distribution of the
   software without specific, written prior permission.
 
   The author disclaim all warranties with regard to this
@@ -33,7 +33,7 @@
  *
  *  Driver for the USART subsystem on supported USB AVRs.
  */
+
 /** \ingroup Group_PeripheralDrivers
  *  @defgroup Group_Serial Serial USART Driver - LUFA/Drivers/Peripheral/Serial.h
  *
  *  The following files must be built with any user project that uses this module:
  *    - LUFA/Drivers/Peripheral/Serial.c <i>(Makefile source module name: LUFA_SRC_SERIAL)</i>
  *
- *  \section Module Description
+ *  \section Sec_ModDescription Module Description
  *  Hardware serial USART driver. This module provides an easy to use driver for
  *  the setup of and transfer of data over the AVR's USART port.
  *
+ *  \section Sec_ExampleUsage Example Usage
+ *  The following snippet is an example of how this module may be used within a typical
+ *  application.
+ *
+ *  \code
+ *      // Initialise the serial USART driver before first use, with 9600 baud (and no double-speed mode)
+ *      Serial_Init(9600, false);
+ *
+ *      // Send a string through the USART
+ *      Serial_TxString("Test String\r\n");
+ *
+ *      // Receive a byte through the USART
+ *      uint8_t DataByte = Serial_RxByte();
+ *  \endcode
+ *
  *  @{
  */
+
 #ifndef __SERIAL_H__
 #define __SERIAL_H__
 
@@ -55,7 +70,8 @@
                #include <avr/io.h>
                #include <avr/pgmspace.h>
                #include <stdbool.h>
-               
+               #include <stdio.h>
+
                #include "../../Common/Common.h"
                #include "../Misc/TerminalCodes.h"
 
                        extern "C" {
                #endif
 
+       /* Private Interface - For use in library only: */
+       #if !defined(__DOXYGEN__)
+               /* External Variables: */
+                       extern FILE USARTSerialStream;
+       
+               /* Function Prototypes: */
+                       int Serial_putchar(char DataByte,
+                                          FILE *Stream);
+                       int Serial_getchar(FILE *Stream);
+                       int Serial_getchar_Blocking(FILE *Stream);
+       #endif
+
        /* Public Interface - May be used in end-application: */
                /* Macros: */
                        /** Macro for calculating the baud value from a given baud rate when the U2X (double speed) bit is
                         *
                         *  \param[in] FlashStringPtr  Pointer to a string located in program space.
                         */
-                       void Serial_TxString_P(const char* FlashStringPtr) ATTR_NON_NULL_PTR_ARG(1);
+                       void Serial_SendString_P(const char* FlashStringPtr) ATTR_NON_NULL_PTR_ARG(1);
 
                        /** Transmits a given string located in SRAM memory through the USART.
                         *
                         *  \param[in] StringPtr  Pointer to a string located in SRAM space.
                         */
-                       void Serial_TxString(const char* StringPtr) ATTR_NON_NULL_PTR_ARG(1);
+                       void Serial_SendString(const char* StringPtr) ATTR_NON_NULL_PTR_ARG(1);
+                       
+                       /** Transmits a given buffer located in SRAM memory through the USART.
+                        *
+                        *  \param[in] Buffer  Pointer to a buffer containing the data to send.
+                        *  \param[in] Length  Length of the data to send, in bytes.
+                        */
+                       void Serial_SendData(const uint8_t* Buffer, uint16_t Length) ATTR_NON_NULL_PTR_ARG(1);
 
                /* Inline Functions: */
-                       /** Initialises the USART, ready for serial data transmission and reception. This initialises the interface to
+                       /** Initializes the USART, ready for serial data transmission and reception. This initializes the interface to
                         *  standard 8-bit, no parity, 1 stop bit settings suitable for most applications.
                         *
                         *  \param[in] BaudRate     Serial baud rate, in bits per second.
                        static inline void Serial_Init(const uint32_t BaudRate,
                                                       const bool DoubleSpeed)
                        {
+                               UBRR1  = (DoubleSpeed ? SERIAL_2X_UBBRVAL(BaudRate) : SERIAL_UBBRVAL(BaudRate));
+
+                               UCSR1C = ((1 << UCSZ11) | (1 << UCSZ10));
                                UCSR1A = (DoubleSpeed ? (1 << U2X1) : 0);
                                UCSR1B = ((1 << TXEN1)  | (1 << RXEN1));
-                               UCSR1C = ((1 << UCSZ11) | (1 << UCSZ10));
-                               
-                               DDRD  |= (1 << 3);      
+
+                               DDRD  |= (1 << 3);
                                PORTD |= (1 << 2);
-                               
-                               UBRR1  = (DoubleSpeed ? SERIAL_2X_UBBRVAL(BaudRate) : SERIAL_UBBRVAL(BaudRate));
                        }
 
                        /** Turns off the USART driver, disabling and returning used hardware to their default configuration. */
-                       static inline void Serial_ShutDown(void)
+                       static inline void Serial_Disable(void)
                        {
-                               UCSR1A = 0;
                                UCSR1B = 0;
+                               UCSR1A = 0;
                                UCSR1C = 0;
-                               
-                               DDRD  &= ~(1 << 3);     
-                               PORTD &= ~(1 << 2);
-                               
+
                                UBRR1  = 0;
+
+                               DDRD  &= ~(1 << 3);
+                               PORTD &= ~(1 << 2);
+                       }
+
+                       /** Creates a standard character stream from the USART so that it can be used with all the regular functions
+                        *  in the avr-libc \c <stdio.h> library that accept a \c FILE stream as a destination (e.g. \c fprintf). The created
+                        *  stream is bidirectional and can be used for both input and output functions.
+                        *
+                        *  Reading data from this stream is non-blocking, i.e. in most instances, complete strings cannot be read in by a single
+                        *  fetch, as the endpoint will not be ready at some point in the transmission, aborting the transfer. However, this may
+                        *  be used when the read data is processed byte-per-bye (via \c getc()) or when the user application will implement its own
+                        *  line buffering.
+                        *
+                        *  \param[in,out] Stream  Pointer to a FILE structure where the created stream should be placed, if \c NULL stdio
+                        *                         and stdin will be configured to use the USART.
+                        *
+                        *  \pre The USART must first be configured via a call to \ref Serial_Init() before the stream is used.
+                        */
+                       static inline void Serial_CreateStream(FILE* Stream)
+                       {
+                               if (!(Stream))
+                               {
+                                       Stream = &USARTSerialStream;
+                                       stdin  = Stream;
+                                       stdout = Stream;
+                               }
+                       
+                               *Stream = (FILE)FDEV_SETUP_STREAM(Serial_putchar, Serial_getchar, _FDEV_SETUP_RW);
+                       }
+
+                       /** Identical to \ref Serial_CreateStream(), except that reads are blocking until the calling stream function terminates
+                        *  the transfer.
+                        *
+                        *  \param[in,out] Stream  Pointer to a FILE structure where the created stream should be placed, if \c NULL stdio
+                        *                         and stdin will be configured to use the USART.
+                        *
+                        *  \pre The USART must first be configured via a call to \ref Serial_Init() before the stream is used.
+                        */
+                       static inline void Serial_CreateBlockingStream(FILE* Stream)
+                       {
+                               if (!(Stream))
+                               {
+                                       Stream = &USARTSerialStream;
+                                       stdin  = Stream;
+                                       stdout = Stream;
+                               }
+
+                               *Stream = (FILE)FDEV_SETUP_STREAM(Serial_putchar, Serial_getchar_Blocking, _FDEV_SETUP_RW);
                        }
 
                        /** Indicates whether a character has been received through the USART.
                         *
-                        *  \return Boolean true if a character has been received, false otherwise.
+                        *  \return Boolean \c true if a character has been received, \c false otherwise.
                         */
                        static inline bool Serial_IsCharReceived(void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE;
                        static inline bool Serial_IsCharReceived(void)
                        {
                                return ((UCSR1A & (1 << RXC1)) ? true : false);
                        }
-                       
+
                        /** Transmits a given byte through the USART.
                         *
                         *  \param[in] DataByte  Byte to transmit through the USART.
                         */
-                       static inline void Serial_TxByte(const char DataByte) ATTR_ALWAYS_INLINE;
-                       static inline void Serial_TxByte(const char DataByte)
+                       static inline void Serial_SendByte(const char DataByte) ATTR_ALWAYS_INLINE;
+                       static inline void Serial_SendByte(const char DataByte)
                        {
                                while (!(UCSR1A & (1 << UDRE1)));
                                UDR1 = DataByte;
                        }
 
-                       /** Receives a byte from the USART.
+                       /** Receives the next byte from the USART.
                         *
-                        *  \return Byte received from the USART.
+                        *  \return Next byte received from the USART, or a negative value if no byte has been received.
                         */
-                       static inline char Serial_RxByte(void) ATTR_ALWAYS_INLINE;
-                       static inline char Serial_RxByte(void)
+                       static inline int16_t Serial_ReceiveByte(void) ATTR_ALWAYS_INLINE;
+                       static inline int16_t Serial_ReceiveByte(void)
                        {
-                               while (!(UCSR1A & (1 << RXC1)));
-                               return UDR1; 
+                               if (!(Serial_IsCharReceived()))
+                                 return -1;
+                               
+                               return UDR1;
                        }
 
        /* Disable C linkage for C++ Compilers: */
                #if defined(__cplusplus)
                        }
                #endif
-               
+
 #endif
 
 /** @} */
+