/* $Id: drv_generic_serial.c,v 1.17 2005/05/08 04:32:44 reinelt Exp $ * * generic driver helper for serial and usbserial displays * * Copyright (C) 1999, 2000 Michael Reinelt * Copyright (C) 2004 The LCD4Linux Team * * This file is part of LCD4Linux. * * LCD4Linux 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, or (at your option) * any later version. * * LCD4Linux 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. * * * $Log: drv_generic_serial.c,v $ * Revision 1.17 2005/05/08 04:32:44 reinelt * CodingStyle added and applied * * Revision 1.16 2005/01/18 06:30:23 reinelt * added (C) to all copyright statements * * Revision 1.15 2004/06/26 12:04:59 reinelt * * uh-oh... the last CVS log message messed up things a lot... * * Revision 1.14 2004/06/26 09:27:21 reinelt * * added '-W' to CFLAGS * changed all C++ comments to C ones * cleaned up a lot of signed/unsigned mistakes * * Revision 1.13 2004/06/26 06:12:15 reinelt * * support for Beckmann+Egle Compact Terminals * some mostly cosmetic changes in the MatrixOrbital and USBLCD driver * added debugging to the generic serial driver * fixed a bug in the generic text driver where icons could be drawn outside * the display bounds * * Revision 1.12 2004/06/20 10:09:55 reinelt * * 'const'ified the whole source * * Revision 1.11 2004/06/01 06:45:30 reinelt * * some Fixme's processed * documented some code * * Revision 1.10 2004/05/31 21:05:13 reinelt * * fixed lots of bugs in the Cwlinux driver * do not emit EAGAIN error on the first retry * made plugin_i2c_sensors a bit less 'chatty' * moved init and exit functions to the bottom of plugin_pop3 * * Revision 1.9 2004/05/28 13:51:42 reinelt * * ported driver for Beckmann+Egle Mini-Terminals * added 'flags' parameter to serial_init() * * Revision 1.8 2004/03/03 04:44:16 reinelt * changes (cosmetics?) to the big patch from Martin * hash patch un-applied * * Revision 1.7 2004/03/03 03:47:04 reinelt * big patch from Martin Hejl: * - use qprintf() where appropriate * - save CPU cycles on gettimeofday() * - add quit() functions to free allocated memory * - fixed lots of memory leaks * * Revision 1.6 2004/02/14 11:56:17 reinelt * M50530 driver ported * changed lots of 'char' to 'unsigned char' * * Revision 1.5 2004/02/04 19:10:51 reinelt * Crystalfontz driver nearly finished * * Revision 1.4 2004/02/01 08:05:12 reinelt * Crystalfontz 633 extensions (CRC checking and stuff) * Models table for HD44780 * Noritake VFD BVrightness patch from Bill Paxton * * Revision 1.3 2004/01/29 04:40:02 reinelt * every .c file includes "config.h" now * * Revision 1.2 2004/01/25 05:30:09 reinelt * plugin_netdev for parsing /proc/net/dev added * * Revision 1.1 2004/01/20 14:26:09 reinelt * moved drv_generic to drv_generic_serial * * Revision 1.2 2004/01/20 05:36:59 reinelt * moved text-display-specific stuff to drv_generic_text * moved all the bar stuff from drv_generic_bar to generic_text * * Revision 1.1 2004/01/20 04:51:39 reinelt * moved generic stuff from drv_MatrixOrbital to drv_generic * implemented new-stylish bars which are nearly finished * */ /* * * exported fuctions: * * int drv_generic_serial_open (char *section, char *driver, unsigned int flags) * opens the serial port * * int drv_generic_serial_poll (char *string, int len) * reads from the serial or USB port * without retry * * int drv_generic_serial_read (char *string, int len); * reads from the serial or USB port * with retry * * void drv_generic_serial_write (char *string, int len); * writes to the serial or USB port * * int drv_generic_serial_close (void); * closes the serial port * */ #include "config.h" #include #include #include #include #include #include #include #include #include #include #include #include "debug.h" #include "qprintf.h" #include "cfg.h" #include "drv_generic_serial.h" static char *Section; static char *Driver; static char *Port; static speed_t Speed; static int Device = -1; #define LOCK "/var/lock/LCK..%s" /****************************************/ /*** generic serial/USB communication ***/ /****************************************/ static pid_t drv_generic_serial_lock_port(const char *Port) { char lockfile[256]; char tempfile[256]; char buffer[16]; char *port, *p; int fd, len, pid; if (strncmp(Port, "/dev/", 5) == 0) { port = strdup(Port + 5); } else { port = strdup(Port); } while ((p = strchr(port, '/')) != NULL) { *p = '_'; } qprintf(lockfile, sizeof(lockfile), LOCK, port); qprintf(tempfile, sizeof(tempfile), LOCK, "TMP.XXXXXX"); free(port); if ((fd = mkstemp(tempfile)) == -1) { error("mkstemp(%s) failed: %s", tempfile, strerror(errno)); return -1; } if (fchmod(fd, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH) == -1) { error("fchmod(%s) failed: %s", tempfile, strerror(errno)); close(fd); unlink(tempfile); return -1; } snprintf(buffer, sizeof(buffer), "%10d\n", (int) getpid()); len = strlen(buffer); if (write(fd, buffer, len) != len) { error("write(%s) failed: %s", tempfile, strerror(errno)); close(fd); unlink(tempfile); return -1; } close(fd); while (link(tempfile, lockfile) == -1) { if (errno != EEXIST) { error("link(%s, %s) failed: %s", tempfile, lockfile, strerror(errno)); unlink(tempfile); return -1; } if ((fd = open(lockfile, O_RDONLY)) == -1) { if (errno == ENOENT) continue; /* lockfile disappared */ error("open(%s) failed: %s", lockfile, strerror(errno)); unlink(tempfile); return -1; } len = read(fd, buffer, sizeof(buffer) - 1); if (len < 0) { error("read(%s) failed: %s", lockfile, strerror(errno)); unlink(tempfile); return -1; } buffer[len] = '\0'; if (sscanf(buffer, "%d", &pid) != 1 || pid == 0) { error("scan(%s) failed.", lockfile); unlink(tempfile); return -1; } if (pid == getpid()) { error("%s already locked by us. uh-oh...", lockfile); unlink(tempfile); return 0; } if ((kill(pid, 0) == -1) && errno == ESRCH) { error("removing stale lockfile %s", lockfile); if (unlink(lockfile) == -1 && errno != ENOENT) { error("unlink(%s) failed: %s", lockfile, strerror(errno)); unlink(tempfile); return pid; } continue; } unlink(tempfile); return pid; } unlink(tempfile); return 0; } static pid_t drv_generic_serial_unlock_port(const char *Port) { char lockfile[256]; char *port, *p; if (strncmp(Port, "/dev/", 5) == 0) { port = strdup(Port + 5); } else { port = strdup(Port); } while ((p = strchr(port, '/')) != NULL) { *p = '_'; } qprintf(lockfile, sizeof(lockfile), LOCK, port); unlink(lockfile); free(port); return 0; } int drv_generic_serial_open(const char *section, const char *driver, const unsigned int flags) { int i, fd; pid_t pid; struct termios portset; Section = (char *) section; Driver = (char *) driver; Port = cfg_get(section, "Port", NULL); if (Port == NULL || *Port == '\0') { error("%s: no '%s.Port' entry from %s", Driver, section, cfg_source()); return -1; } if (cfg_number(section, "Speed", 19200, 1200, 115200, &i) < 0) return -1; switch (i) { case 1200: Speed = B1200; break; case 2400: Speed = B2400; break; case 4800: Speed = B4800; break; case 9600: Speed = B9600; break; case 19200: Speed = B19200; break; case 38400: Speed = B38400; break; case 57600: Speed = B57600; break; case 115200: Speed = B115200; break; default: error("%s: unsupported speed '%d' from %s", Driver, i, cfg_source()); return -1; } info("%s: using port '%s' at %d baud", Driver, Port, i); if ((pid = drv_generic_serial_lock_port(Port)) != 0) { if (pid == -1) error("%s: port %s could not be locked", Driver, Port); else error("%s: port %s is locked by process %d", Driver, Port, pid); return -1; } fd = open(Port, O_RDWR | O_NOCTTY | O_NDELAY); if (fd == -1) { error("%s: open(%s) failed: %s", Driver, Port, strerror(errno)); drv_generic_serial_unlock_port(Port); return -1; } if (tcgetattr(fd, &portset) == -1) { error("%s: tcgetattr(%s) failed: %s", Driver, Port, strerror(errno)); drv_generic_serial_unlock_port(Port); return -1; } cfmakeraw(&portset); portset.c_cflag |= flags; cfsetispeed(&portset, Speed); cfsetospeed(&portset, Speed); if (tcsetattr(fd, TCSANOW, &portset) == -1) { error("%s: tcsetattr(%s) failed: %s", Driver, Port, strerror(errno)); drv_generic_serial_unlock_port(Port); return -1; } Device = fd; return Device; } int drv_generic_serial_poll(char *string, const int len) { int ret; if (Device == -1) return -1; ret = read(Device, string, len); if (ret < 0 && errno != EAGAIN) { error("%s: read(%s) failed: %s", Driver, Port, strerror(errno)); } return ret; } int drv_generic_serial_read(char *string, const int len) { int count, run, ret; count = len < 0 ? -len : len; for (run = 0; run < 10; run++) { ret = drv_generic_serial_poll(string, count); if (ret >= 0 || errno != EAGAIN) break; info("%s: read(%s): EAGAIN", Driver, Port); usleep(1000); } if (ret > 0 && ret != count && len > 0) { error("%s: partial read(%s): len=%d ret=%d", Driver, Port, len, ret); } return ret; } void drv_generic_serial_write(const char *string, const int len) { int run, ret; #if 0 int i; for (i = 0; i < len; i++) { int c = string[i]; debug("serial_write: %03d %03o 0x%02x %c", c, c, c, iscntrl(c) ? '*' : c); } #endif if (Device == -1) return; for (run = 0; run < 10; run++) { ret = write(Device, string, len); if (ret >= 0 || errno != EAGAIN) break; if (run > 0) info("%s: write(%s): EAGAIN #%d", Driver, Port, run); usleep(1000); } if (ret < 0) { error("%s: write(%s) failed: %s", Driver, Port, strerror(errno)); } else if (ret != len) { error("%s: partial write(%s): len=%d ret=%d", Driver, Port, len, ret); } return; } int drv_generic_serial_close(void) { info("%s: closing port %s", Driver, Port); close(Device); drv_generic_serial_unlock_port(Port); free(Port); return 0; }