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

1 files changed, 337 insertions, 0 deletions

diff --git a/apps/nshlib/nsh_usbconsole.c b/apps/nshlib/nsh_usbconsole.c
new file mode 100644
index 000000000..800b36413
--- /dev/null
+++ b/apps/nshlib/nsh_usbconsole.c
@@ -0,0 +1,337 @@
+/****************************************************************************
+ * apps/nshlib/nsh_usbconsole.c
+ *
+ *   Copyright (C) 2012-2014 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>
+
+#ifdef CONFIG_CDCACM
+#  include <nuttx/usb/cdcacm.h>
+#endif
+
+#ifdef CONFIG_CDCACM
+#  include <nuttx/usb/pl2303.h>
+#endif
+
+#include "nsh.h"
+#include "nsh_console.h"
+
+#ifdef HAVE_USB_CONSOLE
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+ /****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nsh_configstdio
+ *
+ * Description:
+ *   Configure standard I/O
+ *
+ ****************************************************************************/
+
+static void nsh_configstdio(int fd)
+{
+  /* Make sure the stdin, stdout, and stderr are closed */
+
+  (void)fclose(stdin);
+  (void)fclose(stdout);
+  (void)fclose(stderr);
+
+  /* Dup the fd to create standard fd 0-2 */
+
+  (void)dup2(fd, 0);
+  (void)dup2(fd, 1);
+  (void)dup2(fd, 2);
+
+  /* fdopen to get the stdin, stdout and stderr streams. The following logic depends
+   * on the fact that the library layer will allocate FILEs in order.  And since
+   * we closed stdin, stdout, and stderr above, that is what we should get.
+   *
+   * fd = 0 is stdin  (read-only)
+   * fd = 1 is stdout (write-only, append)
+   * fd = 2 is stderr (write-only, append)
+   */
+
+  (void)fdopen(0, "r");
+  (void)fdopen(1, "a");
+  (void)fdopen(2, "a");
+}
+
+/****************************************************************************
+ * Name: nsh_nullstdio
+ *
+ * Description:
+ *   Use /dev/null for standard I/O
+ *
+ ****************************************************************************/
+
+static int nsh_nullstdio(void)
+{
+  int fd;
+
+  /* Open /dev/null for read/write access */
+
+  fd = open("/dev/null", O_RDWR);
+  if (fd >= 0)
+    {
+      /* Configure standard I/O to use /dev/null */
+
+      nsh_configstdio(fd);
+
+      /* We can close the original file descriptor now (unless it was one of
+       * 0-2)
+       */
+
+      if (fd > 2)
+       {
+          close(fd);
+       }
+
+      return OK;
+    }
+
+  return fd;
+}
+
+/****************************************************************************
+ * Name: nsh_waitusbready
+ *
+ * Description:
+ *   Wait for the USB console device to be ready
+ *
+ ****************************************************************************/
+
+static int nsh_waitusbready(void)
+{
+  char inch;
+  ssize_t nbytes;
+  int nlc;
+  int fd;
+
+  /* Don't start the NSH console until the console device is ready.  Chances
+   * are, we get here with no functional console.  The USB console will not
+   * be available until the device is connected to the host and until the
+   * host-side application opens the connection.
+   */
+
+  /* Open the USB serial device for read/write access */
+
+  do
+    {
+      /* Try to open the console */
+
+      fd = open(CONFIG_NSH_USBCONDEV, O_RDWR);
+      if (fd < 0)
+        {
+          /* ENOTCONN means that the USB device is not yet connected. Anything
+           * else is bad.
+           */
+
+          DEBUGASSERT(errno == ENOTCONN);
+
+          /* Sleep a bit and try again */
+
+          sleep(2);
+        }
+    }
+  while (fd < 0);
+
+  /* Now wait until we successfully read a carriage return a few times.
+   * That is a sure way of know that there is something at the other end of
+   * the USB serial connection that is ready to talk with us.  The user needs
+   * to hit ENTER a few times to get things started.
+   */
+
+  nlc = 0;
+  do
+    {
+      /* Read one byte */
+
+      inch = 0;
+      nbytes = read(fd, &inch, 1);
+
+      /* Is it a carriage return (or maybe a newline)? */
+
+      if (nbytes == 1 && (inch == '\n' || inch == '\r'))
+        {
+          /* Yes.. increment the count */
+
+          nlc++;
+        }
+      else
+        {
+          /* No.. Reset the count.  We need to see 3 in a row to continue. */
+
+          nlc = 0;
+        }
+    }
+  while (nlc < 3);
+
+  /* Configure standard I/O */
+
+  nsh_configstdio(fd);
+
+  /* We can close the original file descriptor now (unless it was one of 0-2) */
+
+  if (fd > 2)
+    {
+      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, or
+ *   special USB console devices.  The USB console requires some special
+ *   operations to handle the cases where the session is lost when the
+ *   USB device is unplugged and restarted when the USB device 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();
+  int ret;
+
+  DEBUGASSERT(pstate);
+
+  /* Initialize any USB tracing options that were requested */
+
+#ifdef CONFIG_NSH_USBDEV_TRACE
+  usbtrace_enable(TRACE_BITSET);
+#endif
+
+  /* Initialize the USB serial driver */
+
+#if defined(CONFIG_PL2303) || defined(CONFIG_CDCACM)
+#ifdef CONFIG_CDCACM
+  ret = cdcacm_initialize(CONFIG_NSH_USBDEV_MINOR, NULL);
+#else
+  ret = usbdev_serialinitialize(CONFIG_NSH_USBDEV_MINOR);
+#endif
+
+  UNUSED(ret); /* Eliminate warning if not used */
+  DEBUGASSERT(ret == OK);
+#endif
+
+  /* Configure to use /dev/null if we do not have a valid console. */
+
+#ifndef CONFIG_DEV_CONSOLE
+  (void)nsh_nullstdio();
+#endif
+
+  /* Execute the one-time start-up script (output may go to /dev/null) */
+
+#ifdef CONFIG_NSH_ROMFSETC
+  (void)nsh_initscript(&pstate->cn_vtbl);
+#endif
+
+  /* Now loop, executing creating a session for each USB connection */
+
+  for (;;)
+    {
+      /* Wait for the USB to be connected to the host and switch
+       * standard I/O to the USB serial device.
+       */
+
+      ret = nsh_waitusbready();
+
+      (void)ret; /* Eliminate warning if not used */
+      DEBUGASSERT(ret == OK);
+
+      /* Execute the session */
+
+      (void)nsh_session(pstate);
+
+      /* Switch to /dev/null because we probably no longer have a
+       * valid console device.
+       */
+
+      (void)nsh_nullstdio();
+    }
+}
+
+#endif /* HAVE_USB_CONSOLE */