/**************************************************************************** * graphics/nxterm/nxterm_kbdin.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include "nxterm.h" #ifdef CONFIG_NXTERM_NXKBDIN /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: nxterm_pollnotify ****************************************************************************/ static void nxterm_pollnotify(FAR struct nxterm_state_s *priv, pollevent_t eventset) { irqstate_t flags; int i; /* This function may be called from an interrupt handler */ for (i = 0; i < CONFIG_NXTERM_NPOLLWAITERS; i++) { flags = enter_critical_section(); poll_notify(&priv->fds[i], 1, eventset); leave_critical_section(flags); } } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: nxterm_read * * Description: * The optional NxTerm read method * ****************************************************************************/ ssize_t nxterm_read(FAR struct file *filep, FAR char *buffer, size_t len) { FAR struct nxterm_state_s *priv; ssize_t nread; char ch; int ret; /* Recover our private state structure */ DEBUGASSERT(filep && filep->f_priv); priv = (FAR struct nxterm_state_s *)filep->f_priv; /* Get exclusive access to the driver structure */ ret = nxterm_semwait(priv); if (ret < 0) { gerr("ERROR: nxterm_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 * nxterm_write() will not that it needs to post the semaphore * to wake us up. */ sched_lock(); priv->nwaiters++; nxterm_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 = nxsem_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 = nxterm_semwait(priv); } /* Was the semaphore wait successful? Did we successful re-take the * mutual exclusion semaphore? */ if (ret < 0) { /* No.. One of the two nxterm_semwait's failed. */ gerr("ERROR: nxterm_semwait failed\n"); /* Were we awakened by a signal? Did we read anything before * we received the signal? */ if (ret != -EINTR || nread >= 0) { /* Yes.. return the error. */ nread = ret; } /* 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_NXTERM_KBDBUFSIZE) { priv->tail = 0; } /* Add the character to the user buffer */ buffer[nread] = ch; nread++; } } /* Relinquish the mutual exclusion semaphore */ nxterm_sempost(priv); /* Notify all poll/select waiters that they can write to the FIFO */ errout_without_sem: if (nread > 0) { nxterm_pollnotify(priv, POLLOUT); } /* Return the number of characters actually read */ return nread; } /**************************************************************************** * Name: nxterm_poll ****************************************************************************/ int nxterm_poll(FAR struct file *filep, FAR struct pollfd *fds, bool setup) { FAR struct inode *inode = filep->f_inode; FAR struct nxterm_state_s *priv; pollevent_t eventset; int ret; int i; /* Some sanity checking */ DEBUGASSERT(inode && inode->i_private); priv = inode->i_private; /* Get exclusive access to the driver structure */ ret = nxterm_semwait(priv); if (ret < 0) { gerr("ERROR: nxterm_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_NXTERM_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_NXTERM_NPOLLWAITERS) { gerr("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; } nxterm_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_GRAPHICS if (!slot) { gerr("ERROR: No slot\n"); ret = -EIO; goto errout; } #endif /* Remove all memory of the poll setup */ *slot = NULL; fds->priv = NULL; } errout: nxterm_sempost(priv); return ret; } /**************************************************************************** * Name: nxterm_kbdin * * Description: * This function should be driven by the window kbdin callback function * (see nx.h). When the NxTerm 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 makE * it available to the NxTerm as stdin. * * If CONFIG_NXTERM_NXKBDIN is not selected, then the NxTerm 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 NxTerm windows without CONFIG_NXTERM_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 nxterm_kbdin(NXTERM handle, FAR const uint8_t *buffer, uint8_t buflen) { FAR struct nxterm_state_s *priv; ssize_t nwritten; int nexthead; char ch; int ret; ginfo("buflen=%" PRId8 "\n", buflen); DEBUGASSERT(handle); /* Get the reference to the driver structure from the handle */ priv = (FAR struct nxterm_state_s *)handle; /* Get exclusive access to the driver structure */ ret = nxterm_semwait(priv); if (ret < 0) { gerr("ERROR: nxterm_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_NXTERM_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. */ gerr("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(); /* Notify all poll/select waiters that they can read from the FIFO */ nxterm_pollnotify(priv, POLLIN); for (i = 0; i < priv->nwaiters; i++) { /* Yes.. Notify all of the waiting readers that more data is * available */ nxsem_post(&priv->waitsem); } sched_unlock(); } nxterm_sempost(priv); } #endif /* CONFIG_NXTERM_NXKBDIN */