Resync new repository with old repo r5166

git-svn-id: http://svn.code.sf.net/p/nuttx/code/trunk@5153 42af7a65-404d-4744-a932-0658087f49c3
2026-10-18 05:43:35 +08:00 · 2012-09-17 18:18:44 +00:00
commit 57623d42eb
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+/****************************************************************************
+ * drivers/dev_null.c
+ *
+ *   Copyright (C) 2008-2009, 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 <sys/types.h>
+#include <stdbool.h>
+#include <string.h>
+#include <poll.h>
+#include <errno.h>
+#include <nuttx/fs/fs.h>
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static ssize_t devzero_read(FAR struct file *, FAR char *, size_t);
+static ssize_t devzero_write(FAR struct file *, FAR const char *, size_t);
+#ifndef CONFIG_DISABLE_POLL
+static int     devzero_poll(FAR struct file *filp, FAR struct pollfd *fds,
+                            bool setup);
+#endif
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static const struct file_operations devzero_fops =
+{
+  0,             /* open */
+  0,             /* close */
+  devzero_read,  /* read */
+  devzero_write, /* write */
+  0,             /* seek */
+  0              /* ioctl */
+#ifndef CONFIG_DISABLE_POLL
+  , devzero_poll /* poll */
+#endif
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: devzero_read
+ ****************************************************************************/
+
+static ssize_t devzero_read(FAR struct file *filp, FAR char *buffer, size_t len)
+{
+  memset(buffer, 0, len);
+  return len;
+}
+
+/****************************************************************************
+ * Name: devzero_write
+ ****************************************************************************/
+
+static ssize_t devzero_write(FAR struct file *filp, FAR const char *buffer, size_t len)
+{
+  return len;
+}
+
+/****************************************************************************
+ * Name: devzero_poll
+ ****************************************************************************/
+
+#ifndef CONFIG_DISABLE_POLL
+static int devzero_poll(FAR struct file *filp, FAR struct pollfd *fds,
+                        bool setup)
+{
+  if (setup)
+    {
+      fds->revents |= (fds->events & (POLLIN|POLLOUT));
+      if (fds->revents != 0)
+        {
+          sem_post(fds->sem);
+        }
+    }
+  return OK;
+}
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: devzero_register
+ *
+ * Description:
+ *   Register /dev/zero
+ *
+ ****************************************************************************/
+
+void devzero_register(void)
+{
+  (void)register_driver("/dev/zero", &devzero_fops, 0666, NULL);
+}