/*\r
LUFA Library\r
- Copyright (C) Dean Camera, 2009.\r
+ Copyright (C) Dean Camera, 2010.\r
\r
dean [at] fourwalledcubicle [dot] com\r
www.fourwalledcubicle.com\r
*/\r
\r
/*\r
- Copyright 2009 Dean Camera (dean [at] fourwalledcubicle [dot] com)\r
+ Copyright 2010 Dean Camera (dean [at] fourwalledcubicle [dot] com)\r
\r
Permission to use, copy, modify, distribute, and sell this \r
software and its documentation for any purpose is hereby granted\r
this software.\r
*/\r
\r
+/** \file\r
+ * \brief Device mode driver for the library USB CDC Class driver.\r
+ *\r
+ * Device mode driver for the library USB CDC Class driver.\r
+ *\r
+ * \note This file should not be included directly. It is automatically included as needed by the class driver\r
+ * dispatch header located in LUFA/Drivers/USB/Class/CDC.h.\r
+ */\r
+\r
/** \ingroup Group_USBClassCDC\r
* @defgroup Group_USBClassCDCDevice CDC Class Device Mode Driver\r
*\r
* \section Module Description\r
* Device Mode USB Class driver framework interface, for the CDC USB Class driver.\r
*\r
+ * \note There are several major drawbacks to the CDC-ACM standard USB class, however\r
+ * it is very standardized and thus usually available as a built-in driver on\r
+ * most platforms, and so is a better choice than a proprietary serial class.\r
+ * \r
+ * One major issue with CDC-ACM is that it requires two Interface descriptors,\r
+ * which will upset most hosts when part of a multi-function "Composite" USB\r
+ * device, as each interface will be loaded into a separate driver instance. To\r
+ * conbat this, you should use the "Interface Association Descriptor" addendum to\r
+ * the USB standard which is available on most OSes when creating Composite devices.\r
+ *\r
+ * Another major oversight is that there is no mechanism for the host to notify the\r
+ * device that there is a data sink on the host side ready to accept data. This\r
+ * means that the device may try to send data while the host isn't listening, causing\r
+ * lengthy blocking timeouts in the transmission routines. To combat this, it is\r
+ * recommended that the virtual serial line DTR (Data Terminal Ready) be used where\r
+ * possible to determine if a host application is ready for data.\r
+ *\r
* @{\r
*/\r
\r
extern "C" {\r
#endif\r
\r
+ /* Preprocessor Checks: */\r
+ #if !defined(__INCLUDE_FROM_CDC_DRIVER)\r
+ #error Do not include this file directly. Include LUFA/Drivers/Class/CDC.h instead.\r
+ #endif\r
+ \r
/* Public Interface - May be used in end-application: */\r
/* Type Defines: */\r
- /** Class state structure. An instance of this structure should be made for each CDC interface\r
+ /** \brief CDC Class Device Mode Configuration and State Structure.\r
+ *\r
+ * Class state structure. An instance of this structure should be made for each CDC interface\r
* within the user application, and passed to each of the CDC class driver functions as the\r
* CDCInterfaceInfo parameter. This stores each CDC interface's configuration and state information.\r
*/\r
struct\r
{\r
uint8_t HostToDevice; /**< Control line states from the host to device, as a set of CDC_CONTROL_LINE_OUT_*\r
- * masks.\r
+ * masks. This value is updated each time \ref CDC_Device_USBTask() is called.\r
*/\r
uint8_t DeviceToHost; /**< Control line states from the device to host, as a set of CDC_CONTROL_LINE_IN_*\r
- * masks.\r
+ * masks - to notify the host of changes to these values, call the\r
+ * \ref CDC_Device_SendControlLineStateChange() function.\r
*/\r
- } ControlLineStates;\r
+ } ControlLineStates; /**< Current states of the virtual serial port's control lines between the device and host. */\r
\r
struct\r
{\r
* CDCDevice_LineCodingParity_t enum\r
*/\r
uint8_t DataBits; /**< Bits of data per character of the virtual serial port */\r
- } LineEncoding; \r
+ } LineEncoding; /** Line encoding used in the virtual serial port, for the device's information. This is generally\r
+ * only used if the virtual serial port data is to be reconstructed on a physical UART.\r
+ */ \r
} State; /**< State data for the USB class interface within the device. All elements in this section\r
* are reset to their defaults when the interface is enumerated.\r
*/\r
void EVENT_CDC_Device_ControLineStateChanged(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo) ATTR_NON_NULL_PTR_ARG(1);\r
\r
/** Sends a given string to the attached USB host, if connected. If a host is not connected when the function is called, the\r
- * string is discarded.\r
+ * string is discarded. Bytes will be queued for transmission to the host until either the endpoint bank becomes full, or the\r
+ * \ref CDC_Device_Flush() function is called to flush the pending data to the host. This allows for multiple bytes to be \r
+ * packed into a single endpoint packet, increasing data throughput.\r
+ *\r
+ * \note This function must only be called when the Device state machine is in the DEVICE_STATE_Configured state or\r
+ * the call will fail.\r
*\r
* \param[in,out] CDCInterfaceInfo Pointer to a structure containing a CDC Class configuration and state\r
* \param[in] Data Pointer to the string to send to the host\r
ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);\r
\r
/** Sends a given byte to the attached USB host, if connected. If a host is not connected when the function is called, the\r
- * byte is discarded.\r
+ * byte is discarded. Bytes will be queued for transmission to the host until either the endpoint bank becomes full, or the\r
+ * \ref CDC_Device_Flush() function is called to flush the pending data to the host. This allows for multiple bytes to be \r
+ * packed into a single endpoint packet, increasing data throughput.\r
+ *\r
+ * \note This function must only be called when the Device state machine is in the DEVICE_STATE_Configured state or\r
+ * the call will fail.\r
*\r
* \param[in,out] CDCInterfaceInfo Pointer to a structure containing a CDC Class configuration and state\r
* \param[in] Data Byte of data to send to the host\r
\r
/** Determines the number of bytes received by the CDC interface from the host, waiting to be read.\r
*\r
+ * \note This function must only be called when the Device state machine is in the DEVICE_STATE_Configured state or\r
+ * the call will fail.\r
+ *\r
* \param[in,out] CDCInterfaceInfo Pointer to a structure containing a CDC Class configuration and state\r
*\r
* \return Total number of buffered bytes received from the host\r
* returns 0. The \ref CDC_Device_BytesReceived() function should be queried before data is received to ensure that no data\r
* underflow occurs.\r
*\r
+ * \note This function must only be called when the Device state machine is in the DEVICE_STATE_Configured state or\r
+ * the call will fail.\r
+ *\r
* \param[in,out] CDCInterfaceInfo Pointer to a structure containing a CDC Class configuration and state\r
*\r
* \return Next received byte from the host, or 0 if no data received\r
\r
/** Flushes any data waiting to be sent, ensuring that the send buffer is cleared.\r
*\r
+ * \note This function must only be called when the Device state machine is in the DEVICE_STATE_Configured state or\r
+ * the call will fail.\r
+ *\r
* \param[in,out] CDCInterfaceInfo Pointer to a structure containing a CDC Class configuration and state\r
*\r
* \return A value from the \ref Endpoint_WaitUntilReady_ErrorCodes_t enum\r
* until they are cleared via a second notification. This should be called each time the CDC class driver's \r
* ControlLineStates.DeviceToHost value is updated to push the new states to the USB host.\r
*\r
+ * \note This function must only be called when the Device state machine is in the DEVICE_STATE_Configured state or\r
+ * the call will fail.\r
+ *\r
* \param[in,out] CDCInterfaceInfo Pointer to a structure containing a CDC Class configuration and state\r
*/\r
void CDC_Device_SendControlLineStateChange(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo) ATTR_NON_NULL_PTR_ARG(1);\r
/* Private Interface - For use in library only: */\r
#if !defined(__DOXYGEN__)\r
/* Function Prototypes: */\r
- #if defined(INCLUDE_FROM_CDC_CLASS_DEVICE_C)\r
+ #if defined(__INCLUDE_FROM_CDC_CLASS_DEVICE_C)\r
static int CDC_Device_putchar(char c, FILE* Stream);\r
static int CDC_Device_getchar(FILE* Stream);\r
static int CDC_Device_getchar_Blocking(FILE* Stream);\r
projects / pub / USBasp.git / blobdiff