/****************************************************************************
* 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.
*/
restart:
/* 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;
/* If a read error occurred (nbytes < 0) or an end-of-file was
* encountered (nbytes == 0), then close the driver and start
* over.
*/
if (nbytes <= 0)
{
(void)close(fd);
goto restart;
}
}
}
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 */
