Add blocking versions of the CDC Class driver streams, for applications requiring blocking reads.

2 files changed, 31 insertions, 0 deletions

diff --git a/LUFA/Drivers/USB/Class/Device/CDC.c b/LUFA/Drivers/USB/Class/Device/CDC.c
index c86b970a3..aafe48076 100644
--- a/LUFA/Drivers/USB/Class/Device/CDC.c
+++ b/LUFA/Drivers/USB/Class/Device/CDC.c
@@ -240,6 +240,12 @@ void CDC_Device_CreateStream(USB_ClassInfo_CDC_Device_t* CDCInterfaceInfo, FILE*
 	fdev_set_udata(Stream, CDCInterfaceInfo);

 }

 

+void CDC_Device_CreateBlockingStream(USB_ClassInfo_CDC_Device_t* CDCInterfaceInfo, FILE* Stream)

+{

+	*Stream = (FILE)FDEV_SETUP_STREAM(CDC_Device_putchar, CDC_Device_getchar_Blocking, _FDEV_SETUP_RW);

+	fdev_set_udata(Stream, CDCInterfaceInfo);

+}

+

 static int CDC_Device_putchar(char c, FILE* Stream)

 {

 	return CDC_Device_SendByte((USB_ClassInfo_CDC_Device_t*)fdev_get_udata(Stream), c) ? _FDEV_ERR : 0;

@@ -253,4 +259,15 @@ static int CDC_Device_getchar(FILE* Stream)
 	return CDC_Device_ReceiveByte((USB_ClassInfo_CDC_Device_t*)fdev_get_udata(Stream));

 }

 

+static int CDC_Device_getchar_Blocking(FILE* Stream)

+{

+	while (!(CDC_Device_BytesReceived((USB_ClassInfo_CDC_Device_t*)fdev_get_udata(Stream))))

+	{

+		CDC_Device_USBTask((USB_ClassInfo_CDC_Device_t*)fdev_get_udata(Stream));

+		USB_USBTask();

+	}

+

+	return CDC_Device_ReceiveByte((USB_ClassInfo_CDC_Device_t*)fdev_get_udata(Stream));

+}

+

 #endif

diff --git a/LUFA/Drivers/USB/Class/Device/CDC.h b/LUFA/Drivers/USB/Class/Device/CDC.h
index 857d07335..f5a75077b 100644
--- a/LUFA/Drivers/USB/Class/Device/CDC.h
+++ b/LUFA/Drivers/USB/Class/Device/CDC.h
@@ -213,6 +213,11 @@
 			/** Creates a standard characer stream for the given CDC Device instance so that it can be used with all the regular

 			 *  functions in the avr-libc <stdio.h> library that accept a FILE stream as a destination (e.g. fprintf).

 			 *

+			 *  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 getc()) or when the user application will implement its own

+			 *  line buffering.

+			 *

 			 *  \note The created stream can be given as stdout if desired to direct the standard output from all <stdio.h> functions

 			 *        to the given CDC interface.

 			 *

@@ -221,12 +226,21 @@
 			 */

 			void CDC_Device_CreateStream(USB_ClassInfo_CDC_Device_t* CDCInterfaceInfo, FILE* Stream);

 

+			/** Identical to CDC_Device_CreateStream(), except that reads are blocking until the calling stream function terminates

+			 *  the transfer. While blocking, the USB and CDC service tasks are called repeatedly to maintain USB communications.

+			 *

+			 *  \param[in,out] CDCInterfaceInfo  Pointer to a structure containing a CDC Class configuration and state

+			 *  \param[in,out] Stream  Pointer to a FILE structure where the created stream should be placed

+			 */

+			void CDC_Device_CreateBlockingStream(USB_ClassInfo_CDC_Device_t* CDCInterfaceInfo, FILE* Stream);

+

 	/* Private Interface - For use in library only: */

 	#if !defined(__DOXYGEN__)

 		/* Function Prototypes: */

 			#if defined(INCLUDE_FROM_CDC_CLASS_DEVICE_C)

 				static int CDC_Device_putchar(char c, FILE* Stream);

 				static int CDC_Device_getchar(FILE* Stream);

+				static int CDC_Device_getchar_Blocking(FILE* Stream);

 				

 				void CDC_Device_Event_Stub(void);

 				void EVENT_CDC_Device_LineEncodingChanged(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo)