diff options
Diffstat (limited to 'nuttx/drivers/serial/serial.c')
| -rw-r--r-- | nuttx/drivers/serial/serial.c | 1377 |
1 files changed, 0 insertions, 1377 deletions
diff --git a/nuttx/drivers/serial/serial.c b/nuttx/drivers/serial/serial.c deleted file mode 100644 index 0fed1d6c5..000000000 --- a/nuttx/drivers/serial/serial.c +++ /dev/null @@ -1,1377 +0,0 @@ -/************************************************************************************ - * drivers/serial/serial.c - * - * Copyright (C) 2007-2009, 2011-2013 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 <sys/ioctl.h> -#include <stdint.h> -#include <stdbool.h> -#include <unistd.h> -#include <semaphore.h> -#include <string.h> -#include <fcntl.h> -#include <poll.h> -#include <errno.h> -#include <debug.h> - -#include <nuttx/irq.h> -#include <nuttx/arch.h> -#include <nuttx/fs/fs.h> -#include <nuttx/serial/serial.h> - -/************************************************************************************ - * Definitions - ************************************************************************************/ - -/* The architecture must provide up_putc for this driver */ - -#ifndef CONFIG_ARCH_LOWPUTC -# error "Architecture must provide up_putc() for this driver" -#endif - -#define uart_putc(ch) up_putc(ch) - -#define HALF_SECOND_MSEC 500 -#define HALF_SECOND_USEC 500000L - -/************************************************************************************ - * Private Types - ************************************************************************************/ - -/************************************************************************************ - * Private Function Prototypes - ************************************************************************************/ - -static int uart_open(FAR struct file *filep); -static int uart_close(FAR struct file *filep); -static ssize_t uart_read(FAR struct file *filep, FAR char *buffer, size_t buflen); -static ssize_t uart_write(FAR struct file *filep, FAR const char *buffer, size_t buflen); -static int uart_ioctl(FAR struct file *filep, int cmd, unsigned long arg); -#ifndef CONFIG_DISABLE_POLL -static int uart_poll(FAR struct file *filep, FAR struct pollfd *fds, bool setup); -#endif - -/************************************************************************************ - * Private Variables - ************************************************************************************/ - -static const struct file_operations g_serialops = -{ - uart_open, /* open */ - uart_close, /* close */ - uart_read, /* read */ - uart_write, /* write */ - 0, /* seek */ - uart_ioctl /* ioctl */ -#ifndef CONFIG_DISABLE_POLL - , uart_poll /* poll */ -#endif -}; - -/************************************************************************************ - * Private Functions - ************************************************************************************/ - -/************************************************************************************ - * Name: uart_takesem - ************************************************************************************/ - -static int uart_takesem(FAR sem_t *sem, bool errout) -{ - /* Loop, ignoring interrupts, until we have successfully acquired the semaphore */ - - while (sem_wait(sem) != OK) - { - /* The only case that an error should occur here is if the wait was awakened - * by a signal. - */ - - ASSERT(get_errno() == EINTR); - - /* When the signal is received, should we errout? Or should we just continue - * waiting until we have the semaphore? - */ - - if (errout) - { - return -EINTR; - } - } - - return OK; -} - -/************************************************************************************ - * Name: uart_givesem - ************************************************************************************/ - -#define uart_givesem(sem) (void)sem_post(sem) - -/**************************************************************************** - * Name: uart_pollnotify - ****************************************************************************/ - -#ifndef CONFIG_DISABLE_POLL -static void uart_pollnotify(FAR uart_dev_t *dev, pollevent_t eventset) -{ - int i; - - for (i = 0; i < CONFIG_SERIAL_NPOLLWAITERS; i++) - { - struct pollfd *fds = dev->fds[i]; - if (fds) - { -#ifdef CONFIG_SERIAL_REMOVABLE - fds->revents |= ((fds->events | (POLLERR|POLLHUP)) & eventset); -#else - fds->revents |= (fds->events & eventset); -#endif - if (fds->revents != 0) - { - fvdbg("Report events: %02x\n", fds->revents); - sem_post(fds->sem); - } - } - } -} -#else -# define uart_pollnotify(dev,event) -#endif - -/************************************************************************************ - * Name: uart_putxmitchar - ************************************************************************************/ - -static int uart_putxmitchar(FAR uart_dev_t *dev, int ch) -{ - irqstate_t flags; - int nexthead; - int ret; - - /* Increment to see what the next head pointer will be. We need to use the "next" - * head pointer to determine when the circular buffer would overrun - */ - - nexthead = dev->xmit.head + 1; - if (nexthead >= dev->xmit.size) - { - nexthead = 0; - } - - /* Loop until we are able to add the character to the TX buffer */ - - for (;;) - { - if (nexthead != dev->xmit.tail) - { - dev->xmit.buffer[dev->xmit.head] = ch; - dev->xmit.head = nexthead; - return OK; - } - else - { - /* Inform the interrupt level logic that we are waiting. This and - * the following steps must be atomic. - */ - - flags = irqsave(); - -#ifdef CONFIG_SERIAL_REMOVABLE - /* Check if the removable device is no longer connected while we - * have interrupts off. We do not want the transition to occur - * as a race condition before we begin the wait. - */ - - if (dev->disconnected) - { - irqrestore(flags); - return -ENOTCONN; - } -#endif - /* Wait for some characters to be sent from the buffer with the TX - * interrupt enabled. When the TX interrupt is enabled, uart_xmitchars - * should execute and remove some of the data from the TX buffer. - */ - - dev->xmitwaiting = true; - uart_enabletxint(dev); - ret = uart_takesem(&dev->xmitsem, true); - uart_disabletxint(dev); - irqrestore(flags); - -#ifdef CONFIG_SERIAL_REMOVABLE - /* Check if the removable device was disconnected while we were - * waiting. - */ - - if (dev->disconnected) - { - return -ENOTCONN; - } -#endif - /* Check if we were awakened by signal. */ - - if (ret < 0) - { - /* A signal received while waiting for the xmit buffer to become - * non-full will abort the transfer. - */ - - return -EINTR; - } - } - } - - /* We won't get here. Some compilers may complain that this code is - * unreachable. - */ - - return OK; -} - -/************************************************************************************ - * Name: uart_irqwrite - ************************************************************************************/ - -static inline ssize_t uart_irqwrite(FAR uart_dev_t *dev, FAR const char *buffer, size_t buflen) -{ - ssize_t ret = buflen; - - /* Force each character through the low level interface */ - - for (; buflen; buflen--) - { - int ch = *buffer++; - - /* If this is the console, then we should replace LF with CR-LF */ - - if (ch == '\n') - { - uart_putc('\r'); - } - - /* Output the character, using the low-level direct UART interfaces */ - - uart_putc(ch); - } - - return ret; -} - -/************************************************************************************ - * Name: uart_write - ************************************************************************************/ - -static ssize_t uart_write(FAR struct file *filep, FAR const char *buffer, size_t buflen) -{ - FAR struct inode *inode = filep->f_inode; - FAR uart_dev_t *dev = inode->i_private; - ssize_t nread = buflen; - int ret; - char ch; - - /* We may receive console writes through this path from interrupt handlers and - * from debug output in the IDLE task! In these cases, we will need to do things - * a little differently. - */ - - if (up_interrupt_context() || getpid() == 0) - { -#ifdef CONFIG_SERIAL_REMOVABLE - /* If the removable device is no longer connected, refuse to write to - * the device. - */ - - if (dev->disconnected) - { - return -ENOTCONN; - } -#endif - - /* up_putc() will be used to generate the output in a busy-wait loop. - * up_putc() is only available for the console device. - */ - - if (dev->isconsole) - { - irqstate_t flags = irqsave(); - ret = uart_irqwrite(dev, buffer, buflen); - irqrestore(flags); - return ret; - } - else - { - return -EPERM; - } - } - - /* Only one user can access dev->xmit.head at a time */ - - ret = (ssize_t)uart_takesem(&dev->xmit.sem, true); - if (ret < 0) - { - /* A signal received while waiting for access to the xmit.head will - * abort the transfer. - */ - - return ret; - } - -#ifdef CONFIG_SERIAL_REMOVABLE - /* If the removable device is no longer connected, refuse to write to the - * device. This check occurs after taking the xmit.sem because the - * disconnection event might have occurred while we were waiting for - * access to the transmit buffers. - */ - - if (dev->disconnected) - { - uart_givesem(&dev->xmit.sem); - return -ENOTCONN; - } -#endif - - /* Loop while we still have data to copy to the transmit buffer. - * we add data to the head of the buffer; uart_xmitchars takes the - * data from the end of the buffer. - */ - - uart_disabletxint(dev); - for (; buflen; buflen--) - { - ch = *buffer++; - - /* Do output post-processing */ - -#ifdef CONFIG_SERIAL_TERMIOS - - if (dev->tc_oflag & OPOST) - { - - /* Mapping CR to NL? */ - - if ((ch == '\r') && (dev->tc_oflag & OCRNL)) - { - ch = '\n'; - } - - /* Are we interested in newline processing? */ - - if ((ch == '\n') && (dev->tc_oflag & (ONLCR | ONLRET))) - { - ret = uart_putxmitchar(dev, '\r'); - - if (ret != OK) - { - break; - } - } - - /* Specifically not handled: - * - * OXTABS - primarily a full-screen terminal optimisation - * ONOEOT - Unix interoperability hack - * OLCUC - Not specified by Posix - * ONOCR - low-speed interactive optimisation - */ - - } - -#else /* !CONFIG_SERIAL_TERMIOS */ - - /* If this is the console, convert \n -> \r\n */ - - if (dev->isconsole && ch == '\n') - { - ret = uart_putxmitchar(dev, '\r'); - } - -#endif - - /* Put the character into the transmit buffer */ - - ret = uart_putxmitchar(dev, ch); - - if (ret != OK) - { - break; - } - - } - - if (dev->xmit.head != dev->xmit.tail) - { - uart_enabletxint(dev); - } - - uart_givesem(&dev->xmit.sem); - - /* uart_putxmitchar() might return an error under one of two - * conditions: (1) The wait for buffer space might have been - * interrupted by a signal (ret should be -EINTR), or (2) if - * CONFIG_SERIAL_REMOVABLE is defined, then uart_putxmitchar() - * might also return if the serial device was disconnected - * (wtih -ENOTCONN). - */ - - if (ret < 0) - { - /* POSIX requires that we return -1 and errno set if no data was - * transferred. Otherwise, we return the number of bytes in the - * interrupted transfer. - */ - - if (buflen < nread) - { - /* Some data was transferred. Return the number of bytes that were - * successfully transferred. - */ - - nread -= buflen; - } - else - { - /* No data was transferred. Return the negated error. The VFS layer - * will set the errno value appropriately). - */ - - nread = -ret; - } - } - - return nread; -} - -/************************************************************************************ - * Name: uart_read - ************************************************************************************/ - -static ssize_t uart_read(FAR struct file *filep, FAR char *buffer, size_t buflen) -{ - FAR struct inode *inode = filep->f_inode; - FAR uart_dev_t *dev = inode->i_private; - irqstate_t flags; - ssize_t recvd = 0; - int16_t tail; - int ret; - char ch; - - /* Only one user can access dev->recv.tail at a time */ - - ret = uart_takesem(&dev->recv.sem, true); - if (ret < 0) - { - /* A signal received while waiting for access to the recv.tail will avort - * the transfer. After the transfer has started, we are committed and - * signals will be ignored. - */ - - return ret; - } - - /* Loop while we still have data to copy to the receive buffer. - * we add data to the head of the buffer; uart_xmitchars takes the - * data from the end of the buffer. - */ - - while (recvd < buflen) - { -#ifdef CONFIG_SERIAL_REMOVABLE - /* If the removable device is no longer connected, refuse to read any - * further from the device. - */ - - if (dev->disconnected) - { - if (recvd == 0) - { - recvd = -ENOTCONN; - } - - break; - } -#endif - - /* Check if there is more data to return in the circular buffer. - * NOTE: Rx interrupt handling logic may aynchronously increment - * the head index but must not modify the tail index. The tail - * index is only modified in this function. Therefore, no - * special handshaking is required here. - * - * The head and tail pointers are 16-bit values. The only time that - * the following could be unsafe is if the CPU made two non-atomic - * 8-bit accesses to obtain the 16-bit head index. - */ - - tail = dev->recv.tail; - if (dev->recv.head != tail) - { - /* Take the next character from the tail of the buffer */ - - ch = dev->recv.buffer[tail]; - - /* Increment the tail index. Most operations are done using the - * local variable 'tail' so that the final dev->recv.tail update - * is atomic. - */ - - if (++tail >= dev->recv.size) - { - tail = 0; - } - - dev->recv.tail = tail; - -#ifdef CONFIG_SERIAL_TERMIOS - - /* Do input processing if any is enabled */ - - if (dev->tc_iflag & (INLCR | IGNCR | ICRNL)) - { - - /* \n -> \r or \r -> \n translation? */ - - if ((ch == '\n') && (dev->tc_iflag & INLCR)) - { - ch = '\r'; - } - else if ((ch == '\r') && (dev->tc_iflag & ICRNL)) - { - ch = '\n'; - } - - /* discarding \r ? */ - if ((ch == '\r') & (dev->tc_iflag & IGNCR)) - { - continue; - } - - } - - /* Specifically not handled: - * - * All of the local modes; echo, line editing, etc. - * Anything to do with break or parity errors. - * ISTRIP - we should be 8-bit clean. - * IUCLC - Not Posix - * IXON/OXOFF - no xon/xoff flow control. - */ - -#endif - - /* store the received character */ - - *buffer++ = ch; - recvd++; - - } - -#ifdef CONFIG_DEV_SERIAL_FULLBLOCKS - /* No... then we would have to wait to get receive more data. - * If the user has specified the O_NONBLOCK option, then just - * return what we have. - */ - - else if (filep->f_oflags & O_NONBLOCK) - { - /* If nothing was transferred, then return the -EAGAIN - * error (not zero which means end of file). - */ - - if (recvd < 1) - { - recvd = -EAGAIN; - } - - break; - } -#else - /* No... the circular buffer is empty. Have we returned anything - * to the caller? - */ - - else if (recvd > 0) - { - /* Yes.. break out of the loop and return the number of bytes - * received up to the wait condition. - */ - - break; - } - - /* No... then we would have to wait to get receive some data. - * If the user has specified the O_NONBLOCK option, then do not - * wait. - */ - - else if (filep->f_oflags & O_NONBLOCK) - { - /* Break out of the loop returning -EAGAIN */ - - recvd = -EAGAIN; - break; - } -#endif - /* Otherwise we are going to have to wait for data to arrive */ - - else - { - /* Disable Rx interrupts and test again... */ - - uart_disablerxint(dev); - - /* If the Rx ring buffer still empty? Bytes may have been addded - * between the last time that we checked and when we disabled Rx - * interrupts. - */ - - if (dev->recv.head == dev->recv.tail) - { - /* Yes.. the buffer is still empty. Wait for some characters - * to be received into the buffer with the RX interrupt re- - * enabled. All interrupts are disabled briefly to assure - * that the following operations are atomic. - */ - - flags = irqsave(); - -#ifdef CONFIG_SERIAL_REMOVABLE - /* Check if the removable device is no longer connected while - * we have interrupts off. We do not want the transition to - * occur as a race condition before we begin the wait. - */ - - if (dev->disconnected) - { - uart_enablerxint(dev); - irqrestore(flags); - ret = -ENOTCONN; - break; - } -#endif - /* Now wait with the Rx interrupt re-enabled. NuttX will - * automatically re-enable global interrupts when this thread - * goes to sleep. - */ - - dev->recvwaiting = true; - uart_enablerxint(dev); - ret = uart_takesem(&dev->recvsem, true); - irqrestore(flags); - - /* Was a signal received while waiting for data to be - * received? Was a removable device disconnected while - * we were waiting? - */ - -#ifdef CONFIG_SERIAL_REMOVABLE - if (ret < 0 || dev->disconnected) -#else - if (ret < 0) -#endif - { - /* POSIX requires that we return after a signal is received. - * If some bytes were read, we need to return the number of bytes - * read; if no bytes were read, we need to return -1 with the - * errno set correctly. - */ - - if (recvd == 0) - { - /* No bytes were read, return -EINTR (the VFS layer will - * set the errno value appropriately. - */ - -#ifdef CONFIG_SERIAL_REMOVABLE - recvd = dev->disconnected ? -ENOTCONN : -EINTR; -#else - recvd = -EINTR; -#endif - } - - break; - } - } - else - { - /* No... the ring buffer is no longer empty. Just re-enable Rx - * interrupts and accept the new data on the next time through - * the loop. - */ - - uart_enablerxint(dev); - } - } - } - - uart_givesem(&dev->recv.sem); - return recvd; -} - -/************************************************************************************ - * Name: uart_ioctl - ************************************************************************************/ - -static int uart_ioctl(FAR struct file *filep, int cmd, unsigned long arg) -{ - FAR struct inode *inode = filep->f_inode; - FAR uart_dev_t *dev = inode->i_private; - - /* Handle TTY-level IOCTLs here */ - /* Let low-level driver handle the call first */ - - int ret = dev->ops->ioctl(filep, cmd, arg); - - /* - * The device ioctl() handler returns -ENOTTY when it doesn't know - * how to handle the command. Check if we can handle it here. - */ - if (ret == -ENOTTY) - { - switch (cmd) - { - - case FIONREAD: - { - int count; - irqstate_t state = irqsave(); - - /* determine the number of bytes available in the buffer */ - - if (dev->recv.tail <= dev->recv.head) - { - count = dev->recv.head - dev->recv.tail; - } - else - { - count = dev->recv.size - (dev->recv.tail - dev->recv.head); - } - - irqrestore(state); - - *(int *)arg = count; - ret = 0; - - break; - } - - case FIONWRITE: - { - int count; - irqstate_t state = irqsave(); - - /* determine the number of bytes free in the buffer */ - - if (dev->xmit.head < dev->xmit.tail) - { - count = dev->xmit.tail - dev->xmit.head - 1; - } - else - { - count = dev->xmit.size - (dev->xmit.head - dev->xmit.tail) - 1; - } - - irqrestore(state); - - *(int *)arg = count; - ret = 0; - - break; - } - } - } - - /* Append any higher level TTY flags */ - - else if (ret == OK) - { - switch (cmd) - { -#ifdef CONFIG_SERIAL_TERMIOS - case TCGETS: - { - struct termios *termiosp = (struct termios*)arg; - - if (!termiosp) - { - ret = -EINVAL; - break; - } - - /* and update with flags from this layer */ - - termiosp->c_iflag = dev->tc_iflag; - termiosp->c_oflag = dev->tc_oflag; - termiosp->c_lflag = dev->tc_lflag; - } - - break; - - case TCSETS: - { - struct termios *termiosp = (struct termios*)arg; - - if (!termiosp) - { - ret = -EINVAL; - break; - } - - /* update the flags we keep at this layer */ - - dev->tc_iflag = termiosp->c_iflag; - dev->tc_oflag = termiosp->c_oflag; - dev->tc_lflag = termiosp->c_lflag; - } - - break; -#endif - } - } - return ret; -} - -/**************************************************************************** - * Name: uart_poll - ****************************************************************************/ - -#ifndef CONFIG_DISABLE_POLL -int uart_poll(FAR struct file *filep, FAR struct pollfd *fds, bool setup) -{ - FAR struct inode *inode = filep->f_inode; - FAR uart_dev_t *dev = inode->i_private; - pollevent_t eventset; - int ndx; - int ret; - int i; - - /* Some sanity checking */ - -#if CONFIG_DEBUG - if (!dev || !fds) - { - return -ENODEV; - } -#endif - - /* Are we setting up the poll? Or tearing it down? */ - - ret = uart_takesem(&dev->pollsem, true); - if (ret < 0) - { - /* A signal received while waiting for access to the poll data - * will abort the operation. - */ - - return ret; - } - - if (setup) - { - /* This is a request to set up the poll. Find an available - * slot for the poll structure reference - */ - - for (i = 0; i < CONFIG_SERIAL_NPOLLWAITERS; i++) - { - /* Find an available slot */ - - if (!dev->fds[i]) - { - /* Bind the poll structure and this slot */ - - dev->fds[i] = fds; - fds->priv = &dev->fds[i]; - break; - } - } - - if (i >= CONFIG_SERIAL_NPOLLWAITERS) - { - fds->priv = NULL; - ret = -EBUSY; - goto errout; - } - - /* Should we immediately notify on any of the requested events? - * First, check if the xmit buffer is full. - * - * Get exclusive access to the xmit buffer indices. NOTE: that we do not - * let this wait be interrupted by a signal (we probably should, but that - * would be a little awkward). - */ - - eventset = 0; - (void)uart_takesem(&dev->xmit.sem, false); - - ndx = dev->xmit.head + 1; - if (ndx >= dev->xmit.size) - { - ndx = 0; - } - - if (ndx != dev->xmit.tail) - { - eventset |= (fds->events & POLLOUT); - } - - uart_givesem(&dev->xmit.sem); - - /* Check if the receive buffer is empty. - * - * Get exclusive access to the recv buffer indices. NOTE: that we do not - * let this wait be interrupted by a signal (we probably should, but that - * would be a little awkward). - */ - - (void)uart_takesem(&dev->recv.sem, false); - if (dev->recv.head != dev->recv.tail) - { - eventset |= (fds->events & POLLIN); - } - - uart_givesem(&dev->recv.sem); - -#ifdef CONFIG_SERIAL_REMOVABLE - /* Check if a removable device has been disconnected. */ - - if (dev->disconnected) - { - eventset |= (POLLERR|POLLHUP); - } -#endif - - if (eventset) - { - uart_pollnotify(dev, eventset); - } - - } - else if (fds->priv) - { - /* This is a request to tear down the poll. */ - - struct pollfd **slot = (struct pollfd **)fds->priv; - -#ifdef CONFIG_DEBUG - if (!slot) - { - ret = -EIO; - goto errout; - } -#endif - - /* Remove all memory of the poll setup */ - - *slot = NULL; - fds->priv = NULL; - } - -errout: - uart_givesem(&dev->pollsem); - return ret; -} -#endif - -/************************************************************************************ - * Name: uart_close - * - * Description: - * This routine is called when the serial port gets closed. - * It waits for the last remaining data to be sent. - * - ************************************************************************************/ - -static int uart_close(FAR struct file *filep) -{ - FAR struct inode *inode = filep->f_inode; - FAR uart_dev_t *dev = inode->i_private; - irqstate_t flags; - - /* Get exclusive access to the close semaphore (to synchronize open/close operations. - * NOTE: that we do not let this wait be interrupted by a signal. Technically, we - * should, but almost no one every checks the return value from close() so we avoid - * a potential memory leak by ignoring signals in this case. - */ - - (void)uart_takesem(&dev->closesem, false); - if (dev->open_count > 1) - { - dev->open_count--; - uart_givesem(&dev->closesem); - return OK; - } - - /* There are no more references to the port */ - - dev->open_count = 0; - - /* Stop accepting input */ - - uart_disablerxint(dev); - - /* Now we wait for the transmit buffer to clear */ - - while (dev->xmit.head != dev->xmit.tail) - { -#ifndef CONFIG_DISABLE_SIGNALS - usleep(HALF_SECOND_USEC); -#else - up_mdelay(HALF_SECOND_MSEC); -#endif - } - - /* And wait for the TX fifo to drain */ - - while (!uart_txempty(dev)) - { -#ifndef CONFIG_DISABLE_SIGNALS - usleep(HALF_SECOND_USEC); -#else - up_mdelay(HALF_SECOND_MSEC); -#endif - } - - /* Free the IRQ and disable the UART */ - - flags = irqsave(); /* Disable interrupts */ - uart_detach(dev); /* Detach interrupts */ - if (!dev->isconsole) /* Check for the serial console UART */ - { - uart_shutdown(dev); /* Disable the UART */ - } - - irqrestore(flags); - - uart_givesem(&dev->closesem); - return OK; - } - -/************************************************************************************ - * Name: uart_open - * - * Description: - * This routine is called whenever a serial port is opened. - * - ************************************************************************************/ - -static int uart_open(FAR struct file *filep) -{ - struct inode *inode = filep->f_inode; - uart_dev_t *dev = inode->i_private; - uint8_t tmp; - int ret; - - /* If the port is the middle of closing, wait until the close is finished. - * If a signal is received while we are waiting, then return EINTR. - */ - - ret = uart_takesem(&dev->closesem, true); - if (ret < 0) - { - /* A signal received while waiting for the last close operation. */ - - return ret; - } - -#ifdef CONFIG_SERIAL_REMOVABLE - /* If the removable device is no longer connected, refuse to open the - * device. We check this after obtaining the close semaphore because - * we might have been waiting when the device was disconnected. - */ - - if (dev->disconnected) - { - ret = -ENOTCONN; - goto errout_with_sem; - } -#endif - - /* Start up serial port */ - /* Increment the count of references to the device. */ - - tmp = dev->open_count + 1; - if (tmp == 0) - { - /* More than 255 opens; uint8_t overflows to zero */ - - ret = -EMFILE; - goto errout_with_sem; - } - - /* Check if this is the first time that the driver has been opened. */ - - if (tmp == 1) - { - irqstate_t flags = irqsave(); - - /* If this is the console, then the UART has already been initialized. */ - - if (!dev->isconsole) - { - /* Perform one time hardware initialization */ - - ret = uart_setup(dev); - if (ret < 0) - { - irqrestore(flags); - goto errout_with_sem; - } - } - - /* In any event, we do have to configure for interrupt driven mode of - * operation. Attach the hardware IRQ(s). Hmm.. should shutdown() the - * the device in the rare case that uart_attach() fails, tmp==1, and - * this is not the console. - */ - - ret = uart_attach(dev); - if (ret < 0) - { - uart_shutdown(dev); - irqrestore(flags); - goto errout_with_sem; - } - - /* Mark the io buffers empty */ - - dev->xmit.head = 0; - dev->xmit.tail = 0; - dev->recv.head = 0; - dev->recv.tail = 0; - - /* initialise termios state */ - -#ifdef CONFIG_SERIAL_TERMIOS - - dev->tc_iflag = 0; - if (dev->isconsole == true) - { - - /* enable \n -> \r\n translation for the console */ - - dev->tc_oflag = OPOST | ONLCR; - } - else - { - dev->tc_oflag = 0; - } - -#endif - - /* Enable the RX interrupt */ - - uart_enablerxint(dev); - irqrestore(flags); - } - - /* Save the new open count on success */ - - dev->open_count = tmp; - -errout_with_sem: - uart_givesem(&dev->closesem); - return ret; -} - -/************************************************************************************ - * Public Functions - ************************************************************************************/ - -/************************************************************************************ - * Name: uart_register - * - * Description: - * Register serial console and serial ports. - * - ************************************************************************************/ - -int uart_register(FAR const char *path, FAR uart_dev_t *dev) -{ - sem_init(&dev->xmit.sem, 0, 1); - sem_init(&dev->recv.sem, 0, 1); - sem_init(&dev->closesem, 0, 1); - sem_init(&dev->xmitsem, 0, 0); - sem_init(&dev->recvsem, 0, 0); -#ifndef CONFIG_DISABLE_POLL - sem_init(&dev->pollsem, 0, 1); -#endif - - /* Setup termios flags */ - -#ifdef CONFIG_SERIAL_TERMIOS - - if (dev->isconsole == true) - { - - /* enable \n -> \r\n translation for the console as early as possible */ - - dev->tc_oflag = OPOST | ONLCR; - dev->tc_iflag = 0; - } - -#endif - - dbg("Registering %s\n", path); - return register_driver(path, &g_serialops, 0666, dev); -} - -/************************************************************************************ - * Name: uart_datareceived - * - * Description: - * This function is called from uart_recvchars when new serial data is place in - * the driver's circular buffer. This function will wake-up any stalled read() - * operations that are waiting for incoming data. - * - ************************************************************************************/ - -void uart_datareceived(FAR uart_dev_t *dev) -{ - /* Is there a thread waiting for read data? */ - - if (dev->recvwaiting) - { - /* Yes... wake it up */ - - dev->recvwaiting = false; - (void)sem_post(&dev->recvsem); - } - - /* Notify all poll/select waiters that they can read from the recv buffer */ - - uart_pollnotify(dev, POLLIN); - -} - -/************************************************************************************ - * Name: uart_datasent - * - * Description: - * This function is called from uart_xmitchars after serial data has been sent, - * freeing up some space in the driver's circular buffer. This function will - * wake-up any stalled write() operations that was waiting for space to buffer - * outgoing data. - * - ************************************************************************************/ - -void uart_datasent(FAR uart_dev_t *dev) -{ - /* Is there a thread waiting for space in xmit.buffer? */ - - if (dev->xmitwaiting) - { - /* Yes... wake it up */ - - dev->xmitwaiting = false; - (void)sem_post(&dev->xmitsem); - } - - /* Notify all poll/select waiters that they can write to xmit buffer */ - - uart_pollnotify(dev, POLLOUT); -} - -/************************************************************************************ - * Name: uart_connected - * - * Description: - * Serial devices (like USB serial) can be removed. In that case, the "upper - * half" serial driver must be informed that there is no longer a valid serial - * channel associated with the driver. - * - * In this case, the driver will terminate all pending transfers wint ENOTCONN and - * will refuse all further transactions while the "lower half" is disconnected. - * The driver will continue to be registered, but will be in an unusable state. - * - * Conversely, the "upper half" serial driver needs to know when the serial - * device is reconnected so that it can resume normal operations. - * - * Assumptions/Limitations: - * This function may be called from an interrupt handler. - * - ************************************************************************************/ - -#ifdef CONFIG_SERIAL_REMOVABLE -void uart_connected(FAR uart_dev_t *dev, bool connected) -{ - irqstate_t flags; - - /* Is the device disconnected? */ - - flags = irqsave(); - dev->disconnected = !connected; - if (!connected) - { - /* Yes.. wake up all waiting threads. Each thread should detect the - * disconnection and return the ENOTCONN error. - */ - - /* Is there a thread waiting for space in xmit.buffer? */ - - if (dev->xmitwaiting) - { - /* Yes... wake it up */ - - dev->xmitwaiting = false; - (void)sem_post(&dev->xmitsem); - } - - /* Is there a thread waiting for read data? */ - - if (dev->recvwaiting) - { - /* Yes... wake it up */ - - dev->recvwaiting = false; - (void)sem_post(&dev->recvsem); - } - - /* Notify all poll/select waiters that and hangup occurred */ - - uart_pollnotify(dev, (POLLERR|POLLHUP)); - } - - irqrestore(flags); -} -#endif - - - |