📄 ppdevinit.c
字号:
/*****************************************************************************//* * ppdevinit.c -- Parport access via Linux PPDEV device (init routines). * * Copyright (C) 1998-1999 Thomas Sailer (sailer@ife.ee.ethz.ch) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * Please note that the GPL allows you to use the driver, NOT the radio. * In order to use the radio, you need a license from the communications * authority of your country. * *//*****************************************************************************/#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <unistd.h>#include <sys/ioctl.h>#include <errno.h>#include <string.h>#include <stdlib.h>#include "parport.h"#include "ppdev.h"/* ---------------------------------------------------------------------- */extern int pp_dev_fd;extern int pp_dev_mode;extern const struct parport_ops parport_dev_ops;extern void parport_dev_exit(void);/* ---------------------------------------------------------------------- */int parport_init_ppdev(const char *path){ int datadir = 0; if ((pp_dev_fd = open(path, O_RDWR | O_NONBLOCK)) == -1) { lprintf(0, "Cannot open ppdev device %s (error %s)\n", path, strerror(errno)); return -1; } if (ioctl(pp_dev_fd, PPEXCL, 0)) { lprintf(0, "Cannot set exclusive mode on ppdev device %s (error %s)\n", path, strerror(errno)); goto err; } if (ioctl(pp_dev_fd, PPCLAIM, 0)) { lprintf(0, "Cannot claim ppdev device %s (error %s)\n", path, strerror(errno)); goto err; } pp_dev_mode = IEEE1284_MODE_COMPAT; if (ioctl(pp_dev_fd, PPSETMODE, &pp_dev_mode)) { lprintf(0, "Cannot set mode on ppdev device %s (error %s)\n", path, strerror(errno)); goto err; } if (ioctl(pp_dev_fd, PPDATADIR, &datadir)) { lprintf(0, "Cannot set data direction on ppdev device %s (error %s)\n", path, strerror(errno)); goto err; } if (atexit(parport_dev_exit)) { lprintf(0, "Cannot install atexit handler (error %s)\n", strerror(errno)); goto errrelease; } parport_ops = parport_dev_ops; return 0;errrelease: ioctl(pp_dev_fd, PPRELEASE, 0);err: close(pp_dev_fd); pp_dev_fd = -1; return -1;}
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -