NSH: Add an option to take stdin from a USB keyboard device

1 files changed, 222 insertions, 0 deletions

diff --git a/apps/nshlib/nsh_usbkeyboard.c b/apps/nshlib/nsh_usbkeyboard.c
new file mode 100644
index 000000000..845d56a88
--- /dev/null
+++ b/apps/nshlib/nsh_usbkeyboard.c
@@ -0,0 +1,222 @@
+/****************************************************************************
+ * apps/nshlib/nsh_usbkeyboard.c
+ *
+ *   Copyright (C) 2014 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 <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <assert.h>
+#include <debug.h>
+
+#include "nsh.h"
+#include "nsh_console.h"
+
+#if defined(HAVE_USB_KEYBOARD) && !defined(HAVE_USB_CONSOLE)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+ /****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nsh_wait_usbready
+ *
+ * Description:
+ *   Wait for the USB keyboard device to be ready
+ *
+ ****************************************************************************/
+
+static int nsh_wait_usbready(FAR const char *msg)
+{
+  int fd;
+
+  /* Don't start the NSH console until the keyboard device is ready.  Chances
+   * are, we get here with no functional stdin.  The USB keyboard device will
+   * not be available until the device is connected to the host and enumerated.
+   */
+
+  /* Open the USB keyboard device for read-only access */
+
+  do
+    {
+      /* Try to open the console */
+
+      fd = open(NSH_USBKBD_DEVNAME, O_RDONLY);
+      if (fd < 0)
+        {
+          /* ENOENT means that the USB device is not yet connected and,
+           * hence, has no entry under /dev.  Anything else would be bad.
+           */
+
+          DEBUGASSERT(errno == ENOENT);
+
+          /* Let the user know that we are waiting */
+
+          if (msg)
+            {
+              /* Show the waiting message only one time after the failure
+               * to open the keyboard device.
+               */
+
+              puts(msg);
+              fflush(stdout);
+              msg = NULL;
+            }
+
+          /* Sleep a bit and try again */
+
+          sleep(2);
+        }
+    }
+  while (fd < 0);
+
+  /* Okay.. we have successfully opened a keyboard device
+   *
+   * Close standard fd 0.  Unbeknownst to stdin.
+   * NOTE: This might not be portable behavior!
+   */
+
+  (void)close(0);
+
+  /* Dup the fd to create standard fd 0.  stdin should not know */
+
+  (void)dup2(fd, 0);
+
+  /* Close the keyboard device that we just opened */
+
+  close(fd);
+  return OK;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nsh_consolemain (USB console version)
+ *
+ * Description:
+ *   This interfaces maybe to called or started with task_start to start a
+ *   single an NSH instance that operates on stdin and stdout.  This
+ *   function does not return.
+ *
+ *   This function handles generic /dev/console character devices for output
+ *   but uses a special USB keyboard device for input.  The USB keyboard
+ *   requires some special operations to handle the cases where the session
+ *   input is lost when the USB keyboard is unplugged and restarted when the
+ *   USB keyboard is plugged in again.
+ *
+ * Input Parameters:
+ *   Standard task start-up arguments.  These are not used.  argc may be
+ *   zero and argv may be NULL.
+ *
+ * Returned Values:
+ *   This function does not return nor does it ever exit (unless the user
+ *   executes the NSH exit command).
+ *
+ ****************************************************************************/
+
+int nsh_consolemain(int argc, char *argv[])
+{
+  FAR struct console_stdio_s *pstate = nsh_newconsole();
+  FAR const char *msg;
+  int ret;
+
+  DEBUGASSERT(pstate);
+
+  /* Initialize any USB tracing options that were requested */
+
+#ifdef CONFIG_NSH_USBDEV_TRACE
+  usbtrace_enable(TRACE_BITSET);
+#endif
+
+  /* Execute the one-time start-up script.  Any output will go to /dev/console. */
+
+#ifdef CONFIG_NSH_ROMFSETC
+  (void)nsh_initscript(&pstate->cn_vtbl);
+#endif
+
+  /* Now loop, executing creating a session for each USB connection */
+
+  msg = "Waiting for keyboard to be connected...\n";
+  for (;;)
+    {
+      /* Wait for the USB to be connected to the host and switch
+       * standard I/O to the USB serial device.
+       */
+
+      ret = nsh_wait_usbready(msg);
+
+      (void)ret; /* Eliminate warning if not used */
+      DEBUGASSERT(ret == OK);
+
+      /* Execute the session */
+
+      (void)nsh_session(pstate);
+
+      /* We lost the connection.  Wait for the keyboard to
+       * be re-connected.
+       */
+
+      msg = "Please re-connect the keyboard...\n";
+    }
+}
+
+#endif /* HAVE_USB_KEYBOARD && !HAVE_USB_CONSOLE */