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- /* Teensyduino Core Library
- * http://www.pjrc.com/teensy/
- * Copyright (c) 2013 PJRC.COM, LLC.
- * Modified by Jacob Alexander 2013-2015
- *
- * Permission is hereby granted, free of charge, to any person obtaining
- * a copy of this software and associated documentation files (the
- * "Software"), to deal in the Software without restriction, including
- * without limitation the rights to use, copy, modify, merge, publish,
- * distribute, sublicense, and/or sell copies of the Software, and to
- * permit persons to whom the Software is furnished to do so, subject to
- * the following conditions:
- *
- * 1. The above copyright notice and this permission notice shall be
- * included in all copies or substantial portions of the Software.
- *
- * 2. If the Software is incorporated into a build system that allows
- * selection among a list of target devices, then similar target
- * devices manufactured by PJRC.COM must be included in the list of
- * target devices and selectable in the same manner.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
- * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
- * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
- * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
- * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
- // ----- Includes -----
-
- // Compiler Includes
- #include <string.h> // For memcpy
-
- // Project Includes
- #include <Lib/OutputLib.h>
-
- // Local Includes
- #include "usb_dev.h"
- #include "usb_serial.h"
-
-
-
- // ----- Defines -----
-
- #define TRANSMIT_FLUSH_TIMEOUT 5 /* in milliseconds */
-
- // Maximum number of transmit packets to queue so we don't starve other endpoints for memory
- #define TX_PACKET_LIMIT 8
-
- // When the PC isn't listening, how long do we wait before discarding data? If this is
- // too short, we risk losing data during the stalls that are common with ordinary desktop
- // software. If it's too long, we stall the user's program when no software is running.
- #define TX_TIMEOUT_MSEC 70
-
- #if F_CPU == 96000000
- #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 596)
- #elif F_CPU == 72000000
- #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 512) // XXX Correct?
- #elif F_CPU == 48000000
- #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 428)
- #elif F_CPU == 24000000
- #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 262)
- #endif
-
-
-
- // ----- Variables -----
-
- // serial port settings (baud rate, control signals, etc) set
- // by the PC. These are ignored, but kept in RAM.
- volatile uint8_t usb_cdc_line_coding[7] = { 0x00, 0xE1, 0x00, 0x00, 0x00, 0x00, 0x08 };
- volatile uint8_t usb_cdc_line_rtsdtr = 0;
- volatile uint8_t usb_cdc_transmit_flush_timer = 0;
-
- static usb_packet_t *rx_packet = NULL;
- static usb_packet_t *tx_packet = NULL;
- static volatile uint8_t tx_noautoflush = 0;
-
- // When we've suffered the transmit timeout, don't wait again until the computer
- // begins accepting data. If no software is running to receive, we'll just discard
- // data as rapidly as Serial.print() can generate it, until there's something to
- // actually receive it.
- static uint8_t transmit_previous_timeout = 0;
-
-
-
- // ----- Functions -----
-
- // get the next character, or -1 if nothing received
- int usb_serial_getchar()
- {
- unsigned int i;
- int c;
-
- if ( !rx_packet )
- {
- if ( !usb_configuration )
- return -1;
- rx_packet = usb_rx( CDC_RX_ENDPOINT );
- if ( !rx_packet )
- return -1;
- }
- i = rx_packet->index;
- c = rx_packet->buf[i++];
- if ( i >= rx_packet->len )
- {
- usb_free( rx_packet );
- rx_packet = NULL;
- }
- else
- {
- rx_packet->index = i;
- }
- return c;
- }
-
- // peek at the next character, or -1 if nothing received
- int usb_serial_peekchar()
- {
- if ( !rx_packet )
- {
- if ( !usb_configuration )
- return -1;
- rx_packet = usb_rx( CDC_RX_ENDPOINT );
- if ( !rx_packet )
- return -1;
- }
- if ( !rx_packet )
- return -1;
- return rx_packet->buf[ rx_packet->index ];
- }
-
- // number of bytes available in the receive buffer
- int usb_serial_available()
- {
- int count = usb_rx_byte_count( CDC_RX_ENDPOINT );
- if ( rx_packet )
- count += rx_packet->len - rx_packet->index;
- return count;
- }
-
- // read a block of bytes to a buffer
- int usb_serial_read( void *buffer, uint32_t size )
- {
- uint8_t *p = (uint8_t *)buffer;
- uint32_t qty, count=0;
-
- while ( size )
- {
- if ( !usb_configuration )
- break;
- if ( !rx_packet )
- {
- rx:
- rx_packet = usb_rx(CDC_RX_ENDPOINT);
- if ( !rx_packet )
- break;
- if ( rx_packet->len == 0 )
- {
- usb_free(rx_packet);
- goto rx;
- }
- }
- qty = rx_packet->len - rx_packet->index;
- if ( qty > size )
- qty = size;
- memcpy( p, rx_packet->buf + rx_packet->index, qty );
- p += qty;
- count += qty;
- size -= qty;
- rx_packet->index += qty;
- if ( rx_packet->index >= rx_packet->len )
- {
- usb_free( rx_packet );
- rx_packet = NULL;
- }
- }
- return count;
- }
-
- // discard any buffered input
- void usb_serial_flush_input()
- {
- usb_packet_t *rx;
-
- if ( !usb_configuration )
- return;
- if ( rx_packet )
- {
- usb_free( rx_packet );
- rx_packet = NULL;
- }
- while (1)
- {
- rx = usb_rx( CDC_RX_ENDPOINT );
- if ( !rx )
- break;
- usb_free( rx );
- }
- }
-
- // transmit a character. 0 returned on success, -1 on error
- int usb_serial_putchar( uint8_t c )
- {
- return usb_serial_write( &c, 1 );
- }
-
- int usb_serial_write( const void *buffer, uint32_t size )
- {
- uint32_t len;
- uint32_t wait_count;
- const uint8_t *src = (const uint8_t *)buffer;
- uint8_t *dest;
-
- tx_noautoflush = 1;
- while ( size > 0 )
- {
- if ( !tx_packet )
- {
- wait_count = 0;
- while ( 1 )
- {
- if ( !usb_configuration )
- {
- tx_noautoflush = 0;
- return -1;
- }
- if ( usb_tx_packet_count( CDC_TX_ENDPOINT ) < TX_PACKET_LIMIT )
- {
- tx_noautoflush = 1;
- tx_packet = usb_malloc();
- if ( tx_packet )
- break;
- tx_noautoflush = 0;
- }
- if ( ++wait_count > TX_TIMEOUT || transmit_previous_timeout )
- {
- transmit_previous_timeout = 1;
- return -1;
- }
- yield();
- }
- }
- transmit_previous_timeout = 0;
- len = CDC_TX_SIZE - tx_packet->index;
- if ( len > size )
- len = size;
- dest = tx_packet->buf + tx_packet->index;
- tx_packet->index += len;
- size -= len;
- while ( len-- > 0 )
- *dest++ = *src++;
- if ( tx_packet->index >= CDC_TX_SIZE )
- {
- tx_packet->len = CDC_TX_SIZE;
- usb_tx( CDC_TX_ENDPOINT, tx_packet );
- tx_packet = NULL;
- }
- usb_cdc_transmit_flush_timer = TRANSMIT_FLUSH_TIMEOUT;
- }
- tx_noautoflush = 0;
- return 0;
- }
-
- void usb_serial_flush_output()
- {
- if ( !usb_configuration )
- return;
- tx_noautoflush = 1;
- if ( tx_packet )
- {
- usb_cdc_transmit_flush_timer = 0;
- tx_packet->len = tx_packet->index;
- usb_tx( CDC_TX_ENDPOINT, tx_packet );
- tx_packet = NULL;
- }
- else
- {
- usb_packet_t *tx = usb_malloc();
- if ( tx )
- {
- usb_cdc_transmit_flush_timer = 0;
- usb_tx( CDC_TX_ENDPOINT, tx );
- }
- else
- {
- usb_cdc_transmit_flush_timer = 1;
- }
- }
- tx_noautoflush = 0;
- }
-
- void usb_serial_flush_callback()
- {
- if ( tx_noautoflush )
- return;
- if ( tx_packet )
- {
- tx_packet->len = tx_packet->index;
- usb_tx( CDC_TX_ENDPOINT, tx_packet );
- tx_packet = NULL;
- } else {
- usb_packet_t *tx = usb_malloc();
- if ( tx )
- {
- usb_tx( CDC_TX_ENDPOINT, tx );
- }
- else
- {
- usb_cdc_transmit_flush_timer = 1;
- }
- }
- }
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