X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/85cf2027373cfbe6f6fb257a84a59df0d74f3e1a..9da01ee78b59bcaed0d73e3f77d2f284885bfc76:/Projects/USBtoSerial/USBtoSerial.c diff --git a/Projects/USBtoSerial/USBtoSerial.c b/Projects/USBtoSerial/USBtoSerial.c index c26667df9..fb9ac8770 100644 --- a/Projects/USBtoSerial/USBtoSerial.c +++ b/Projects/USBtoSerial/USBtoSerial.c @@ -1,13 +1,13 @@ /* LUFA Library - Copyright (C) Dean Camera, 2010. + Copyright (C) Dean Camera, 2012. dean [at] fourwalledcubicle [dot] com www.lufa-lib.org */ /* - Copyright 2010 Dean Camera (dean [at] fourwalledcubicle [dot] com) + Copyright 2012 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 @@ -31,16 +31,22 @@ /** \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 @@ -51,21 +57,28 @@ USB_ClassInfo_CDC_Device_t VirtualSerial_CDC_Interface = .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, + .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. */ @@ -73,11 +86,11 @@ int main(void) { 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 (;;) { @@ -90,22 +103,43 @@ int main(void) if (!(ReceivedByte < 0)) 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)) + uint16_t BufferCount = RingBuffer_GetCount(&USARTtoUSB_Buffer); + if ((TIFR0 & (1 << TOV0)) || (BufferCount > (uint8_t)(sizeof(USARTtoUSB_Buffer_Data) * .75))) { - /* Clear flush timer expiry flag */ - TIFR0 |= (1 << TOV0); - - /* Read bytes from the USART receive buffer into the USB IN endpoint */ - while (BufferCount--) - CDC_Device_SendByte(&VirtualSerial_CDC_Interface, RingBuffer_Remove(&USARTtoUSB_Buffer)); + 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()) + { + /* Clear flush timer expiry flag */ + TIFR0 |= (1 << TOV0); + + /* 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(); @@ -152,8 +186,8 @@ void EVENT_USB_Device_ConfigurationChanged(void) 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); }