/* Teensyduino Core Library * http://www.pjrc.com/teensy/ * Copyright (c) 2013 PJRC.COM, LLC. * * 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. */ #include "usb_dev.h" #include "usb_serial.h" #include "core_pins.h" // for yield() //#include "HardwareSerial.h" #include // for memcpy() // defined by usb_dev.h -> usb_desc.h #if defined(CDC_STATUS_INTERFACE) && defined(CDC_DATA_INTERFACE) #if F_CPU >= 20000000 uint32_t usb_cdc_line_coding[2]; volatile uint32_t usb_cdc_line_rtsdtr_millis; 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; #define TRANSMIT_FLUSH_TIMEOUT 5 /* in milliseconds */ // get the next character, or -1 if nothing received int usb_serial_getchar(void) { 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(void) { 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(void) { int count; 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(void) { 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); } } // 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 == 192000000 #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 1280) #elif F_CPU == 180000000 #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 1200) #elif F_CPU == 168000000 #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 1100) #elif F_CPU == 144000000 #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 932) #elif F_CPU == 120000000 #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 764) #elif F_CPU == 96000000 #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 596) #elif F_CPU == 72000000 #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 512) #elif F_CPU == 48000000 #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 428) #elif F_CPU == 24000000 #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 262) #endif // 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; // 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; } int usb_serial_write_buffer_free(void) { uint32_t len; tx_noautoflush = 1; if (!tx_packet) { if (!usb_configuration || usb_tx_packet_count(CDC_TX_ENDPOINT) >= TX_PACKET_LIMIT || (tx_packet = usb_malloc()) == NULL) { tx_noautoflush = 0; return 0; } } len = CDC_TX_SIZE - tx_packet->index; // TODO: Perhaps we need "usb_cdc_transmit_flush_timer = TRANSMIT_FLUSH_TIMEOUT" // added here, so the SOF interrupt can't take away the available buffer // space we just promised the user could write without blocking? // But does this come with other performance downsides? Could it lead to // buffer data never actually transmitting in some usage cases? More // investigation is needed. // https://github.com/PaulStoffregen/cores/issues/10#issuecomment-61514955 tx_noautoflush = 0; return len; } void usb_serial_flush_output(void) { 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(void) { 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; } } } #endif // F_CPU #endif // CDC_STATUS_INTERFACE && CDC_DATA_INTERFACE