diff options
Diffstat (limited to 'nuttx/drivers/serial/serialirq.c')
-rw-r--r-- | nuttx/drivers/serial/serialirq.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/nuttx/drivers/serial/serialirq.c b/nuttx/drivers/serial/serialirq.c new file mode 100644 index 000000000..fda5b4afb --- /dev/null +++ b/nuttx/drivers/serial/serialirq.c @@ -0,0 +1,186 @@ +/************************************************************************************ + * drivers/serial/serialirq.c + * + * Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ************************************************************************************/ + +/************************************************************************************ + * Included Files + ************************************************************************************/ + +#include <nuttx/config.h> + +#include <sys/types.h> +#include <stdint.h> +#include <semaphore.h> +#include <debug.h> +#include <nuttx/serial/serial.h> + +/************************************************************************************ + * Pre-processor Definitions + ************************************************************************************/ + +/************************************************************************************ + * Private Types + ************************************************************************************/ + +/************************************************************************************ + * Private Function Prototypes + ************************************************************************************/ + +/************************************************************************************ + * Private Variables + ************************************************************************************/ + +/************************************************************************************ + * Private Functions + ************************************************************************************/ + +/************************************************************************************ + * Public Functions + ************************************************************************************/ + +/************************************************************************************ + * Name: uart_xmitchars + * + * Description: + * This function is called from the UART interrupt handler when an interrupt + * is received indicating that there is more space in the transmit FIFO. This + * function will send characters from the tail of the xmit buffer while the driver + * write() logic adds data to the head of the xmit buffer. + * + ************************************************************************************/ + +void uart_xmitchars(FAR uart_dev_t *dev) +{ + uint16_t nbytes = 0; + + /* Send while we still have data & room in the fifo */ + + while (dev->xmit.head != dev->xmit.tail && uart_txready(dev)) + { + /* Send the next byte */ + + uart_send(dev, dev->xmit.buffer[dev->xmit.tail]); + nbytes++; + + /* Increment the tail index */ + + if (++(dev->xmit.tail) >= dev->xmit.size) + { + dev->xmit.tail = 0; + } + } + + /* When all of the characters have been sent from the buffer disable the TX + * interrupt. + */ + + if (dev->xmit.head == dev->xmit.tail) + { + uart_disabletxint(dev); + } + + /* If any bytes were removed from the buffer, inform any waiters there there is + * space available. + */ + + if (nbytes) + { + uart_datasent(dev); + } +} + +/************************************************************************************ + * Name: uart_receivechars + * + * Description: + * This function is called from the UART interrupt handler when an interrupt + * is received indicating that are bytes available in the receive fifo. This + * function will add chars to head of receive buffer. Driver read() logic will + * take characters from the tail of the buffer. + * + ************************************************************************************/ + +void uart_recvchars(FAR uart_dev_t *dev) +{ + unsigned int status; + int nexthead = dev->recv.head + 1; + uint16_t nbytes = 0; + + if (nexthead >= dev->recv.size) + { + nexthead = 0; + } + + /* Loop putting characters into the receive buffer until either there are no + * further characters to available. + */ + + while (uart_rxavailable(dev)) + { + char ch = uart_receive(dev, &status); + + /* If the RX buffer becomes full, then the serial data is discarded. This is + * necessary because on most serial hardware, you must read the data in order + * to clear the RX interrupt. An option on some hardware might be to simply + * disable RX interrupts until the RX buffer becomes non-FULL. However, that + * would probably just cause the overrun to occur in hardware (unless it has + * some large internal buffering). + */ + + if (nexthead != dev->recv.tail) + { + /* Add the character to the buffer */ + + dev->recv.buffer[dev->recv.head] = ch; + nbytes++; + + /* Increment the head index */ + + dev->recv.head = nexthead; + if (++nexthead >= dev->recv.size) + { + nexthead = 0; + } + } + } + + /* If any bytes were added to the buffer, inform any waiters there there is new + * incoming data available. + */ + + if (nbytes) + { + uart_datareceived(dev); + } +} |