From 652042111c7c058bd56d9847002f166507f492d4 Mon Sep 17 00:00:00 2001
From: Dean Camera <dean@fourwalledcubicle.com>
Date: Thu, 12 Nov 2009 12:47:15 +0000
Subject: [PATCH] Add blocking versions of the CDC Class driver streams, for
applications requiring blocking reads.
---
LUFA/Drivers/USB/Class/Device/CDC.c | 17 +++++++++++++++++
LUFA/Drivers/USB/Class/Device/CDC.h | 14 ++++++++++++++
LUFA/Drivers/USB/Class/Host/CDC.c | 11 +++++++++++
LUFA/Drivers/USB/Class/Host/CDC.h | 9 +++++++++
4 files changed, 51 insertions(+)
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)
diff --git a/LUFA/Drivers/USB/Class/Host/CDC.c b/LUFA/Drivers/USB/Class/Host/CDC.c
index 5467e3df3..fcfa86d79 100644
--- a/LUFA/Drivers/USB/Class/Host/CDC.c
+++ b/LUFA/Drivers/USB/Class/Host/CDC.c
@@ -353,6 +353,17 @@ static int CDC_Host_getchar(FILE* Stream)
return CDC_Host_ReceiveByte((USB_ClassInfo_CDC_Host_t*)fdev_get_udata(Stream));
}
+static int CDC_Host_getchar_Blocking(FILE* Stream)
+{
+ while (!(CDC_Host_BytesReceived((USB_ClassInfo_CDC_Host_t*)fdev_get_udata(Stream))))
+ {
+ CDC_Host_USBTask((USB_ClassInfo_CDC_Host_t*)fdev_get_udata(Stream));
+ USB_USBTask();
+ }
+
+ return CDC_Host_ReceiveByte((USB_ClassInfo_CDC_Host_t*)fdev_get_udata(Stream));
+}
+
void CDC_Host_Event_Stub(void)
{
diff --git a/LUFA/Drivers/USB/Class/Host/CDC.h b/LUFA/Drivers/USB/Class/Host/CDC.h
index 0ee24be48..9b5fb0c2b 100644
--- a/LUFA/Drivers/USB/Class/Host/CDC.h
+++ b/LUFA/Drivers/USB/Class/Host/CDC.h
@@ -219,6 +219,14 @@
*/
void CDC_Host_CreateStream(USB_ClassInfo_CDC_Host_t* CDCInterfaceInfo, FILE* Stream);
+ /** Identical to CDC_Host_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_Host_CreateBlockingStream(USB_ClassInfo_CDC_Host_t* CDCInterfaceInfo, FILE* Stream);
+
/** CDC class driver event for a control line state change on a CDC host interface. This event fires each time the device notifies
* the host of a control line state change (containing the virtual serial control line states, such as DCD) and may be hooked in the
* user program by declaring a handler function with the same name and parameters listed here. The new control line states
@@ -247,6 +255,7 @@
#if defined(INCLUDE_FROM_CDC_CLASS_HOST_C)
static int CDC_Host_putchar(char c, FILE* Stream);
static int CDC_Host_getchar(FILE* Stream);
+ static int CDC_Host_getchar_Blocking(FILE* Stream);
void CDC_Host_Event_Stub(void);
void EVENT_CDC_Host_ControLineStateChanged(USB_ClassInfo_CDC_Host_t* const CDCInterfaceInfo)
--
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