Added new PRNT_Host_BytesReceived() and PRNT_Host_ReceiveByte() functions to the Print Host Class driver.

Demos/Host/ClassDriver/PrinterHost/PrinterHost.c

@@ -134,7 +134,7 @@ int main(void)
 			
 				printf_P(PSTR("Sending Test Page (%d bytes)...\r\n"), TestPageLength);
 
-				if (PRNT_Host_SendData(&Printer_PRNT_Interface, &TestPageData, TestPageLength) != PIPE_RWSTREAM_NoError)
+				if (PRNT_Host_SendString(&Printer_PRNT_Interface, &TestPageData, TestPageLength) != PIPE_RWSTREAM_NoError)
 				{
 					puts_P(PSTR("Error Sending Page Data.\r\n"));
 					LEDs_SetAllLEDs(LEDMASK_USB_ERROR);

Demos/Host/LowLevel/PrinterHost/Lib/PrinterCommands.c

@@ -56,11 +56,8 @@ uint8_t Printer_SendData(const void* const PrinterCommands,
 	  return ErrorCode;
 
 	Pipe_ClearOUT();
-	while (!(Pipe_IsOUTReady()))
+	
-	{
+	Pipe_WaitUntilReady();
-		if (USB_HostState == HOST_STATE_Unattached)
-		  return PIPE_RWSTREAM_DeviceDisconnected;
-	}
 	
 	Pipe_Freeze();
 

LUFA/Drivers/USB/Class/Host/Printer.c

@@ -182,9 +182,9 @@ uint8_t PRNT_Host_SoftReset(USB_ClassInfo_PRNT_Host_t* const PRNTInterfaceInfo)
 	return USB_Host_SendControlRequest(NULL);
 }
 
-uint8_t PRNT_Host_SendData(USB_ClassInfo_PRNT_Host_t* const PRNTInterfaceInfo,
+uint8_t PRNT_Host_SendString(USB_ClassInfo_PRNT_Host_t* const PRNTInterfaceInfo,
-                           void* PrinterCommands,
+                             void* Buffer,
-                           const uint16_t CommandSize)
+                             const uint16_t Length)
 {
 	uint8_t ErrorCode;
 
@@ -194,19 +194,70 @@ uint8_t PRNT_Host_SendData(USB_ClassInfo_PRNT_Host_t* const PRNTInterfaceInfo,
 	Pipe_SelectPipe(PRNTInterfaceInfo->Config.DataOUTPipeNumber);
 	Pipe_Unfreeze();
 	
-	if ((ErrorCode = Pipe_Write_Stream_LE(PrinterCommands, CommandSize, NO_STREAM_CALLBACK)) != PIPE_RWSTREAM_NoError)
+	if ((ErrorCode = Pipe_Write_Stream_LE(Buffer, Length, NO_STREAM_CALLBACK)) != PIPE_RWSTREAM_NoError)
 	  return ErrorCode;
 
 	Pipe_ClearOUT();
-	while (!(Pipe_IsOUTReady()))
+	
+	ErrorCode = Pipe_WaitUntilReady();
+	
+	Pipe_Freeze();
+
+	return ErrorCode;
+}
+
+uint16_t PRNT_Host_BytesReceived(USB_ClassInfo_PRNT_Host_t* const PRNTInterfaceInfo)
+{
+	if ((USB_HostState != HOST_STATE_Configured) || !(PRNTInterfaceInfo->State.IsActive))
+	  return 0;
+	
+	Pipe_SelectPipe(PRNTInterfaceInfo->Config.DataINPipeNumber);
+	Pipe_Unfreeze();
+
+	if (Pipe_IsINReceived())
 	{
-		if (USB_HostState == HOST_STATE_Unattached)
+		if (!(Pipe_BytesInPipe()))
-		  return PIPE_RWSTREAM_DeviceDisconnected;
+		{
+			Pipe_ClearIN();
+			Pipe_Freeze();
+			return 0;
+		}
+		else
+		{
+			Pipe_Freeze();
+			return Pipe_BytesInPipe();
+		}
+	}
+	else
+	{
+		Pipe_Freeze();
+		
+		return 0;
+	}
+}
+
+int16_t PRNT_Host_ReceiveByte(USB_ClassInfo_PRNT_Host_t* const PRNTInterfaceInfo)
+{
+	if ((USB_HostState != HOST_STATE_Configured) || !(PRNTInterfaceInfo->State.IsActive))
+	  return PIPE_RWSTREAM_DeviceDisconnected;
+
+	int16_t ReceivedByte = -1;
+
+	Pipe_SelectPipe(PRNTInterfaceInfo->Config.DataINPipeNumber);
+	Pipe_Unfreeze();
+
+	if (Pipe_IsINReceived())
+	{
+		if (Pipe_BytesInPipe())
+		  ReceivedByte = Pipe_Read_Byte();
+
+		if (!(Pipe_BytesInPipe()))
+		  Pipe_ClearIN();
 	}
 	
 	Pipe_Freeze();
 
-	return PIPE_RWSTREAM_NoError;
+	return ReceivedByte;
 }
 
 uint8_t PRNT_Host_GetDeviceID(USB_ClassInfo_PRNT_Host_t* const PRNTInterfaceInfo,

LUFA/Drivers/USB/Class/Host/Printer.h

@@ -167,15 +167,42 @@
 			 *       call will fail.
 			 *
 			 *  \param[in,out] PRNTInterfaceInfo  Pointer to a structure containing a Printer Class host configuration and state.
-			 *  \param[in]     PrinterCommands    Pointer to a buffer containing the raw command stream to send to the printer.
+			 *  \param[in]     Buffer             Pointer to a buffer containing the raw command stream to send to the printer.
-			 *  \param[in]     CommandSize        Size in bytes of the command stream to be sent.
+			 *  \param[in]     Length             Size in bytes of the command stream to be sent.
 			 *
 			 *  \return A value from the \ref Pipe_Stream_RW_ErrorCodes_t enum.
 			 */
-			uint8_t PRNT_Host_SendData(USB_ClassInfo_PRNT_Host_t* const PRNTInterfaceInfo,
+			uint8_t PRNT_Host_SendString(USB_ClassInfo_PRNT_Host_t* const PRNTInterfaceInfo,
-			                           void* PrinterCommands, 
+			                             void* PrinterCommands, 
-			                           const uint16_t CommandSize) ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
+			                             const uint16_t Length) ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 
+			/** Determines the number of bytes received by the printer interface from the device, waiting to be read. This indicates the number
+			 *  of bytes in the IN pipe bank only, and thus the number of calls to \ref PRNT_Host_ReceiveByte() which are guaranteed to succeed
+			 *  immediately. If multiple bytes are to be received, they should be buffered by the user application, as the pipe bank will not be
+			 *  released back to the USB controller until all bytes are read.
+			 *
+			 *  \pre This function must only be called when the Host state machine is in the HOST_STATE_Configured state or the
+			 *       call will fail.
+			 *
+			 *  \param[in,out] PRNTInterfaceInfo  Pointer to a structure containing a Printer Class host configuration and state.
+			 *
+			 *  \return Total number of buffered bytes received from the device.
+			 */
+			uint16_t PRNT_Host_BytesReceived(USB_ClassInfo_PRNT_Host_t* const PRNTInterfaceInfo);			
+			
+			/** Reads a byte of data from the device. If no data is waiting to be read of if a USB device is not connected, the function
+			 *  returns a negative value. The \ref PRNT_Host_BytesReceived() function may be queried in advance to determine how many bytes
+			 *  are currently buffered in the Printer interface's data receive pipe.
+			 *
+			 *  \pre This function must only be called when the Host state machine is in the HOST_STATE_Configured state or the
+			 *       call will fail.
+			 *
+			 *  \param[in,out] PRNTInterfaceInfo  Pointer to a structure containing a Printer Class host configuration and state.
+			 *
+			 *  \return Next received byte from the device, or a negative value if no data received.
+			 */
+			int16_t PRNT_Host_ReceiveByte(USB_ClassInfo_PRNT_Host_t* const PRNTInterfaceInfo);
+			
 			/** Retrieves the attached printer device's ID string, formatted according to IEEE 1284. This string is sent as a
 			 *  Unicode string from the device and is automatically converted to an ASCII encoded C string by this function, thus
 			 *  the maximum reportable string length is two less than the size given (to accommodate the Unicode string length

LUFA/ManPages/ChangeLog.txt

@@ -16,6 +16,7 @@
   *  - Added new USB_Device_GetFrameNumber() and USB_Host_GetFrameNumber() functions to retrieve the current USB frame number
   *  - Added new USB_Host_EnableSOFEvents(), USB_Host_DisableSOFEvents() and EVENT_USB_Host_StartOfFrame() for the user application
   *    handling of USB Start of Frame events while in USB Host mode
+  *  - Added new PRNT_Host_BytesReceived() and PRNT_Host_ReceiveByte() functions to the Print Host Class driver
   *
   *  <b>Changed:</b>
   *  - Removed complicated logic for the Endpoint_ConfigureEndpoint() function to use inlined or function called versions

LUFA/ManPages/MigrationInformation.txt

@@ -23,6 +23,10 @@
  *      now "const void** const DescriptorAddress". Existing applications should update their callback signatures to match this, and
  *      eliminate any casting of descriptor pointers to a non-const pointer.
  *
+ *  <b>Host Mode</b>
+ *    - The PRNT_Host_SendData() function has been renamed to \ref PRNT_Host_SendString(). Existing applications should simply
+ *      replace all references to the obsolete function name with the new function name.
+ *
  * \section Sec_Migration100807 Migrating from 100513 to 100807
  *
  *  <b>Non-USB Library Components</b>