diff options
Diffstat (limited to 'nuttx/graphics/nxconsole/nxcon_kbdin.c')
-rw-r--r-- | nuttx/graphics/nxconsole/nxcon_kbdin.c | 489 |
1 files changed, 489 insertions, 0 deletions
diff --git a/nuttx/graphics/nxconsole/nxcon_kbdin.c b/nuttx/graphics/nxconsole/nxcon_kbdin.c new file mode 100644 index 000000000..f4b116c46 --- /dev/null +++ b/nuttx/graphics/nxconsole/nxcon_kbdin.c @@ -0,0 +1,489 @@ +/**************************************************************************** + * nuttx/graphics/nxconsole/nxcon_kbdin.c + * + * Copyright (C) 2012 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 <fcntl.h> +#include <sched.h> +#include <assert.h> +#include <errno.h> +#include <debug.h> + +#include "nxcon_internal.h" + +#ifdef CONFIG_NXCONSOLE_NXKBDIN + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: nxcon_pollnotify + ****************************************************************************/ + +#ifndef CONFIG_DISABLE_POLL +static void nxcon_pollnotify(FAR struct nxcon_state_s *priv, pollevent_t eventset) +{ + FAR struct pollfd *fds; + irqstate_t flags; + int i; + + /* This function may be called from an interrupt handler */ + + for (i = 0; i < CONFIG_NXCONSOLE_NPOLLWAITERS; i++) + { + flags = irqsave(); + fds = priv->fds[i]; + if (fds) + { + fds->revents |= (fds->events & eventset); + if (fds->revents != 0) + { + sem_post(fds->sem); + } + } + irqrestore(flags); + } +} +#else +# define nxcon_pollnotify(priv,event) +#endif + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: nxcon_read + * + * Description: + * The optional NxConsole read method + * + ****************************************************************************/ + +ssize_t nxcon_read(FAR struct file *filep, FAR char *buffer, size_t len) +{ + FAR struct nxcon_state_s *priv; + ssize_t nread; + char ch; + int ret; + + /* Recover our private state structure */ + + DEBUGASSERT(filep && filep->f_priv); + priv = (FAR struct nxcon_state_s *)filep->f_priv; + + /* Get exclusive access to the driver structure */ + + ret = nxcon_semwait(priv); + if (ret < 0) + { + gdbg("ERROR: nxcon_semwait failed\n"); + return ret; + } + + /* Loop until something is read */ + + for (nread = 0; nread < len; ) + { + /* Get the next byte from the buffer */ + + if (priv->head == priv->tail) + { + /* The circular buffer is empty. Did we read anything? */ + + if (nread > 0) + { + /* Yes.. break out to return what we have. */ + + break; + } + + /* If the driver was opened with O_NONBLOCK option, then don't wait. + * Just return EGAIN. + */ + + if (filep->f_oflags & O_NONBLOCK) + { + nread = -EAGAIN; + break; + } + + /* Otherwise, wait for something to be written to the circular + * buffer. Increment the number of waiters so that the nxcon_write() + * will not that it needs to post the semaphore to wake us up. + */ + + sched_lock(); + priv->nwaiters++; + nxcon_sempost(priv); + + /* We may now be pre-empted! But that should be okay because we + * have already incremented nwaiters. Pre-emption is disabled + * but will be re-enabled while we are waiting. + */ + + ret = sem_wait(&priv->waitsem); + + /* Pre-emption will be disabled when we return. So the decrementing + * nwaiters here is safe. + */ + + priv->nwaiters--; + sched_unlock(); + + /* Did we successfully get the waitsem? */ + + if (ret >= 0) + { + /* Yes... then retake the mutual exclusion semaphore */ + + ret = nxcon_semwait(priv); + } + + /* Was the semaphore wait successful? Did we successful re-take the + * mutual exclusion semaphore? + */ + + if (ret < 0) + { + /* No.. One of the two sem_wait's failed. */ + + int errval = errno; + + gdbg("ERROR: nxcon_semwait failed\n"); + + /* Were we awakened by a signal? Did we read anything before + * we received the signal? + */ + + if (errval != EINTR || nread >= 0) + { + /* Yes.. return the error. */ + + nread = -errval; + } + + /* Break out to return what we have. Note, we can't exactly + * "break" out because whichever error occurred, we do not hold + * the exclusion semaphore. + */ + + goto errout_without_sem; + } + } + else + { + /* The circular buffer is not empty, get the next byte from the + * tail index. + */ + + ch = priv->rxbuffer[priv->tail]; + + /* Increment the tail index and re-enable interrupts */ + + if (++priv->tail >= CONFIG_NXCONSOLE_KBDBUFSIZE) + { + priv->tail = 0; + } + + /* Add the character to the user buffer */ + + buffer[nread] = ch; + nread++; + } + } + + /* Relinquish the mutual exclusion semaphore */ + + nxcon_sempost(priv); + + /* Notify all poll/select waiters that they can write to the FIFO */ + +errout_without_sem: + +#ifndef CONFIG_DISABLE_POLL + if (nread > 0) + { + nxcon_pollnotify(priv, POLLOUT); + } +#endif + + /* Return the number of characters actually read */ + + return nread; +} + +/**************************************************************************** + * Name: nxcon_poll + ****************************************************************************/ + +#ifndef CONFIG_DISABLE_POLL +int nxcon_poll(FAR struct file *filep, FAR struct pollfd *fds, bool setup) +{ + FAR struct inode *inode = filep->f_inode; + FAR struct nxcon_state_s *priv; + pollevent_t eventset; + int ndx; + int ret; + int i; + + /* Some sanity checking */ + + DEBUGASSERT(inode && inode->i_private); + priv = inode->i_private; + + /* Get exclusive access to the driver structure */ + + ret = nxcon_semwait(priv); + if (ret < 0) + { + gdbg("ERROR: nxcon_semwait failed\n"); + return ret; + } + + /* Are we setting up the poll? Or tearing it down? */ + + 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_NXCONSOLE_NPOLLWAITERS; i++) + { + /* Find an available slot */ + + if (!priv->fds[i]) + { + /* Bind the poll structure and this slot */ + + priv->fds[i] = fds; + fds->priv = &priv->fds[i]; + break; + } + } + + if (i >= CONFIG_NXCONSOLE_NPOLLWAITERS) + { + gdbg("ERROR: Too many poll waiters\n"); + + fds->priv = NULL; + ret = -EBUSY; + goto errout; + } + + /* Should immediately notify on any of the requested events? + * This driver is always available for transmission. + */ + + eventset = POLLOUT; + + /* Check if the receive buffer is empty */ + + if (priv->head != priv->tail) + { + eventset |= POLLIN; + } + + if (eventset) + { + nxcon_pollnotify(priv, 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) + { + gdbg("ERROR: No slot\n"); + + ret = -EIO; + goto errout; + } +#endif + + /* Remove all memory of the poll setup */ + + *slot = NULL; + fds->priv = NULL; + } + +errout: + nxcon_sempost(priv); + return ret; +} +#endif + +/**************************************************************************** + * Name: nxcon_kbdin + * + * Description: + * This function should be driven by the window kbdin callback function + * (see nx.h). When the NxConsole is the top window and keyboard input is + * received on the top window, that window callback should be directed to + * this function. This function will buffer the keyboard data and may + * it available to the NxConsole as stdin. + * + * If CONFIG_NXCONSOLE_NXKBDIN is not selected, then the NxConsole will + * receive its input from stdin (/dev/console). This works great but + * cannot be shared between different windows. Chaos will ensue if you + * try to support multiple NxConsole windows without CONFIG_NXCONSOLE_NXKBDIN + * + * Input Parameters: + * handle - A handle previously returned by nx_register, nxtk_register, or + * nxtool_register. + * buffer - The array of characters + * buflen - The number of characters that are available in buffer[] + * + * Returned Value: + * None + * + ****************************************************************************/ + +void nxcon_kbdin(NXCONSOLE handle, FAR const uint8_t *buffer, uint8_t buflen) +{ + FAR struct nxcon_state_s *priv; + ssize_t nwritten; + int nexthead; + char ch; + int ret; + + gvdbg("buflen=%d\n"); + DEBUGASSERT(handle); + + /* Get the reference to the driver structure from the handle */ + + priv = (FAR struct nxcon_state_s *)handle; + + /* Get exclusive access to the driver structure */ + + ret = nxcon_semwait(priv); + if (ret < 0) + { + gdbg("ERROR: nxcon_semwait failed\n"); + return; + } + + /* Loop until all of the bytes have been written. This function may be + * called from an interrupt handler! Semaphores cannot be used! + * + * The write logic only needs to modify the head index. Therefore, + * there is a difference in the way that head and tail are protected: + * tail is protected with a semaphore; tail is protected by disabling + * interrupts. + */ + + for (nwritten = 0; nwritten < buflen; nwritten++) + { + /* Add the next character */ + + ch = buffer[nwritten]; + + /* Calculate the write index AFTER the next byte is add to the ring + * buffer + */ + + nexthead = priv->head + 1; + if (nexthead >= CONFIG_NXCONSOLE_KBDBUFSIZE) + { + nexthead = 0; + } + + /* Would the next write overflow the circular buffer? */ + + if (nexthead == priv->tail) + { + /* Yes... Return an indication that nothing was saved in the buffer. */ + + gdbg("ERROR: Keyboard data overrun\n"); + break; + } + + /* No... copy the byte */ + + priv->rxbuffer[priv->head] = ch; + priv->head = nexthead; + } + + /* Was anything written? */ + + if (nwritten > 0) + { + int i; + + /* Are there threads waiting for read data? */ + + sched_lock(); + for (i = 0; i < priv->nwaiters; i++) + { + /* Yes.. Notify all of the waiting readers that more data is available */ + + sem_post(&priv->waitsem); + } + + /* Notify all poll/select waiters that they can write to the FIFO */ + +#ifndef CONFIG_DISABLE_POLL + nxcon_pollnotify(priv, POLLIN); +#endif + sched_unlock(); + } + + nxcon_sempost(priv); +} + +#endif /* CONFIG_NXCONSOLE_NXKBDIN */ |