/**************************************************************************** * apps/nshlib/nsh_usbconsole.c * * Copyright (C) 2012-2014 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include #include #ifdef CONFIG_CDCACM # include #endif #ifdef CONFIG_CDCACM # include #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 */