/*
LUFA Library
- Copyright (C) Dean Camera, 2010.
+ Copyright (C) Dean Camera, 2013.
dean [at] fourwalledcubicle [dot] com
www.lufa-lib.org
*/
/*
- Copyright 2010 Dean Camera (dean [at] fourwalledcubicle [dot] com)
+ Copyright 2013 Dean Camera (dean [at] fourwalledcubicle [dot] com)
Permission to use, copy, modify, distribute, and sell this
software and its documentation for any purpose is hereby granted
advertising or publicity pertaining to distribution of the
software without specific, written prior permission.
- The author disclaim all warranties with regard to this
+ The author disclaims all warranties with regard to this
software, including all implied warranties of merchantability
and fitness. In no event shall the author be liable for any
special, indirect or consequential damages or any damages
/** \file
*
* Main source file for the USBtoSerial project. This file contains the main tasks of
- * the demo and is responsible for the initial application hardware configuration.
+ * the project and is responsible for the initial application hardware configuration.
*/
#include "USBtoSerial.h"
/** Circular buffer to hold data from the host before it is sent to the device via the serial port. */
-RingBuff_t USBtoUSART_Buffer;
+static RingBuffer_t USBtoUSART_Buffer;
+
+/** Underlying data buffer for \ref USBtoUSART_Buffer, where the stored bytes are located. */
+static uint8_t USBtoUSART_Buffer_Data[128];
/** Circular buffer to hold data from the serial port before it is sent to the host. */
-RingBuff_t USARTtoUSB_Buffer;
+static RingBuffer_t USARTtoUSB_Buffer;
+
+/** Underlying data buffer for \ref USARTtoUSB_Buffer, where the stored bytes are located. */
+static uint8_t USARTtoUSB_Buffer_Data[128];
/** LUFA CDC Class driver interface configuration and state information. This structure is
* passed to all CDC Class driver functions, so that multiple instances of the same class
{
.Config =
{
- .ControlInterfaceNumber = 0,
-
- .DataINEndpointNumber = CDC_TX_EPNUM,
- .DataINEndpointSize = CDC_TXRX_EPSIZE,
- .DataINEndpointDoubleBank = false,
-
- .DataOUTEndpointNumber = CDC_RX_EPNUM,
- .DataOUTEndpointSize = CDC_TXRX_EPSIZE,
- .DataOUTEndpointDoubleBank = false,
-
- .NotificationEndpointNumber = CDC_NOTIFICATION_EPNUM,
- .NotificationEndpointSize = CDC_NOTIFICATION_EPSIZE,
- .NotificationEndpointDoubleBank = false,
+ .ControlInterfaceNumber = INTERFACE_ID_CDC_CCI,
+ .DataINEndpoint =
+ {
+ .Address = CDC_TX_EPADDR,
+ .Size = CDC_TXRX_EPSIZE,
+ .Banks = 1,
+ },
+ .DataOUTEndpoint =
+ {
+ .Address = CDC_RX_EPADDR,
+ .Size = CDC_TXRX_EPSIZE,
+ .Banks = 1,
+ },
+ .NotificationEndpoint =
+ {
+ .Address = CDC_NOTIFICATION_EPADDR,
+ .Size = CDC_NOTIFICATION_EPSIZE,
+ .Banks = 1,
+ },
},
};
+
/** Main program entry point. This routine contains the overall program flow, including initial
* setup of all components and the main program loop.
*/
{
SetupHardware();
- RingBuffer_InitBuffer(&USBtoUSART_Buffer);
- RingBuffer_InitBuffer(&USARTtoUSB_Buffer);
+ RingBuffer_InitBuffer(&USBtoUSART_Buffer, USBtoUSART_Buffer_Data, sizeof(USBtoUSART_Buffer_Data));
+ RingBuffer_InitBuffer(&USARTtoUSB_Buffer, USARTtoUSB_Buffer_Data, sizeof(USARTtoUSB_Buffer_Data));
LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
- sei();
+ GlobalInterruptEnable();
for (;;)
{
- /* Read bytes from the USB OUT endpoint into the USART transmit buffer */
- int16_t ReceivedByte = CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);
- if (!(ReceivedByte < 0) && !(RingBuffer_IsFull(&USBtoUSART_Buffer)))
- RingBuffer_Insert(&USBtoUSART_Buffer, ReceivedByte);
-
- /* Check if the UART receive buffer flush timer has expired or the buffer is nearly full */
- RingBuff_Count_t BufferCount = RingBuffer_GetCount(&USARTtoUSB_Buffer);
- if ((TIFR0 & (1 << TOV0)) || (BufferCount > 200))
+ /* Only try to read in bytes from the CDC interface if the transmit buffer is not full */
+ if (!(RingBuffer_IsFull(&USBtoUSART_Buffer)))
{
- TIFR0 |= (1 << TOV0);
+ int16_t ReceivedByte = CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);
- /* Read bytes from the USART receive buffer into the USB IN endpoint */
- while (BufferCount--)
- CDC_Device_SendByte(&VirtualSerial_CDC_Interface, RingBuffer_Remove(&USARTtoUSB_Buffer));
+ /* Store received byte into the USART transmit buffer */
+ if (!(ReceivedByte < 0))
+ RingBuffer_Insert(&USBtoUSART_Buffer, ReceivedByte);
+ }
+
+ uint16_t BufferCount = RingBuffer_GetCount(&USARTtoUSB_Buffer);
+ if (BufferCount)
+ {
+ Endpoint_SelectEndpoint(VirtualSerial_CDC_Interface.Config.DataINEndpoint.Address);
+
+ /* Check if a packet is already enqueued to the host - if so, we shouldn't try to send more data
+ * until it completes as there is a chance nothing is listening and a lengthy timeout could occur */
+ if (Endpoint_IsINReady())
+ {
+ /* Never send more than one bank size less one byte to the host at a time, so that we don't block
+ * while a Zero Length Packet (ZLP) to terminate the transfer is sent if the host isn't listening */
+ uint8_t BytesToSend = MIN(BufferCount, (CDC_TXRX_EPSIZE - 1));
+
+ /* Read bytes from the USART receive buffer into the USB IN endpoint */
+ while (BytesToSend--)
+ {
+ /* Try to send the next byte of data to the host, abort if there is an error without dequeuing */
+ if (CDC_Device_SendByte(&VirtualSerial_CDC_Interface,
+ RingBuffer_Peek(&USARTtoUSB_Buffer)) != ENDPOINT_READYWAIT_NoError)
+ {
+ break;
+ }
+
+ /* Dequeue the already sent byte from the buffer now we have confirmed that no transmission error occurred */
+ RingBuffer_Remove(&USARTtoUSB_Buffer);
+ }
+ }
}
/* Load the next byte from the USART transmit buffer into the USART */
if (!(RingBuffer_IsEmpty(&USBtoUSART_Buffer)))
- Serial_TxByte(RingBuffer_Remove(&USBtoUSART_Buffer));
+ Serial_SendByte(RingBuffer_Remove(&USBtoUSART_Buffer));
CDC_Device_USBTask(&VirtualSerial_CDC_Interface);
USB_USBTask();
/** Configures the board hardware and chip peripherals for the demo's functionality. */
void SetupHardware(void)
{
+#if (ARCH == ARCH_AVR8)
/* Disable watchdog if enabled by bootloader/fuses */
MCUSR &= ~(1 << WDRF);
wdt_disable();
/* Disable clock division */
clock_prescale_set(clock_div_1);
+#endif
/* Hardware Initialization */
LEDs_Init();
USB_Init();
-
- /* Start the flush timer so that overflows occur rapidly to push received bytes to the USB interface */
- TCCR0B = (1 << CS02);
}
/** Event handler for the library USB Connection event. */
LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);
}
-/** Event handler for the library USB Unhandled Control Request event. */
-void EVENT_USB_Device_UnhandledControlRequest(void)
+/** Event handler for the library USB Control Request reception event. */
+void EVENT_USB_Device_ControlRequest(void)
{
CDC_Device_ProcessControlRequest(&VirtualSerial_CDC_Interface);
}
projects / pub / USBasp.git / blobdiff