aboutsummaryrefslogtreecommitdiffstats
path: root/plugin_cpuinfo.c
blob: 42a8e751c7d20e79f68505dec261dd25eb79105e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
/* $Id: plugin_cpuinfo.c,v 1.12 2004/06/26 12:05:00 reinelt Exp $
 *
 * plugin for /proc/cpuinfo parsing
 *
 * Copyright 2003 Michael Reinelt <reinelt@eunet.at>
 * Copyright 2004 The LCD4Linux Team <lcd4linux-devel@users.sourceforge.net>
 *
 * 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: plugin_cpuinfo.c,v $
 * Revision 1.12  2004/06/26 12:05:00  reinelt
 *
 * uh-oh... the last CVS log message messed up things a lot...
 *
 * Revision 1.11  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 1.10  2004/06/17 06:23:43  reinelt
 *
 * hash handling rewritten to solve performance issues
 *
 * Revision 1.9  2004/03/11 06:39:59  reinelt
 * big patch from Martin:
 * - reuse filehandles
 * - memory leaks fixed
 * - earlier busy-flag checking with HD44780
 * - reuse memory for strings in RESULT and hash
 * - netdev_fast to wavid time-consuming regex
 *
 * Revision 1.8  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 1.7  2004/01/29 04:40:02  reinelt
 * every .c file includes "config.h" now
 *
 * Revision 1.6  2004/01/21 10:48:17  reinelt
 * hash_age function added
 *
 * Revision 1.5  2004/01/16 11:12:26  reinelt
 * some bugs in plugin_xmms fixed, parsing moved to own function
 * plugin_proc_stat nearly finished
 *
 * Revision 1.4  2004/01/16 07:26:25  reinelt
 * moved various /proc parsing to own functions
 * made some progress with /proc/stat parsing
 *
 * Revision 1.3  2004/01/15 04:29:45  reinelt
 * moved lcd4linux.conf.sample to *.old
 * lcd4linux.conf.sample with new layout
 * new plugins 'loadavg' and 'meminfo'
 * text widget have pre- and postfix
 *
 * Revision 1.2  2004/01/14 11:33:00  reinelt
 * new plugin 'uname' which does what it's called
 * text widget nearly finished
 * first results displayed on MatrixOrbital
 *
 * Revision 1.1  2004/01/13 10:03:01  reinelt
 * new util 'hash' for associative arrays
 * new plugin 'cpuinfo'
 *
 */

/* 
 * exported functions:
 *
 * int plugin_init_cpuinfo (void)
 *  adds functions to access /proc/cpuinfo
 *
 */


#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>

#include "debug.h"
#include "plugin.h"
#include "hash.h"


static HASH CPUinfo;
static FILE *stream = NULL;

static int parse_cpuinfo (void)
{
  int age;
  
  /* reread every second only */
  age = hash_age(&CPUinfo, NULL);
  if (age > 0 && age <= 1000) return 0;
  
  if (stream == NULL) stream = fopen("/proc/cpuinfo", "r");
  if (stream == NULL) {
    error ("fopen(/proc/cpuinfo) failed: %s", strerror(errno));
    return -1;
  }
  rewind(stream);
  while (!feof(stream)) {
    char buffer[256];
    char *c, *key, *val;
    fgets (buffer, sizeof(buffer), stream);
    c = strchr(buffer, ':');
    if (c == NULL) continue;
    key = buffer; val = c+1;
    /* strip leading blanks from key */
    while (isspace(*key)) *key++ = '\0';
    /* strip trailing blanks from key */
    do *c = '\0'; while (isspace(*--c));
    /* strip leading blanks from value */
    while (isspace(*val)) *val++ = '\0';
    /* strip trailing blanks from value */
    for (c = val; *c != '\0'; c++);
    while (isspace(*--c)) *c = '\0';
    
    /* add entry to hash table */
    hash_put (&CPUinfo, key, val);
      
  }
  return 0;
}
  

static void my_cpuinfo (RESULT *result, RESULT *arg1)
{
  char *key, *val;
  
  if (parse_cpuinfo() < 0) {
    SetResult(&result, R_STRING, ""); 
    return;
  }
  
  key = R2S(arg1);
  val = hash_get(&CPUinfo, key, NULL);
  if (val == NULL) val = "";
  
  SetResult(&result, R_STRING, val); 
}


int plugin_init_cpuinfo (void)
{
  hash_create (&CPUinfo);
  AddFunction ("cpuinfo", 1, my_cpuinfo);
  return 0;
}

void plugin_exit_cpuinfo(void) 
{
  if (stream != NULL) {
    fclose (stream);
    stream = NULL;
  }
  hash_destroy(&CPUinfo);
}
iteral.Number.Float */ .highlight .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */ .highlight .mi { color: #0000DD; font-weight: bold } /* Literal.Number.Integer */ .highlight .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */ .highlight .sa { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Affix */ .highlight .sb { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Backtick */ .highlight .sc { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Char */ .highlight .dl { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Delimiter */ .highlight .sd { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Doc */ .highlight .s2 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Double */ .highlight .se { color: #0044dd; background-color: #fff0f0 } /* Literal.String.Escape */ .highlight .sh { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Heredoc */ .highlight .si { color: #3333bb; background-color: #fff0f0 } /* Literal.String.Interpol */ .highlight .sx { color: #22bb22; background-color: #f0fff0 } /* Literal.String.Other */ .highlight .sr { color: #008800; background-color: #fff0ff } /* Literal.String.Regex */ .highlight .s1 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Single */ .highlight .ss { color: #aa6600; background-color: #fff0f0 } /* Literal.String.Symbol */ .highlight .bp { color: #003388 } /* Name.Builtin.Pseudo */ .highlight .fm { color: #0066bb; font-weight: bold } /* Name.Function.Magic */ .highlight .vc { color: #336699 } /* Name.Variable.Class */ .highlight .vg { color: #dd7700 } /* Name.Variable.Global */ .highlight .vi { color: #3333bb } /* Name.Variable.Instance */ .highlight .vm { color: #336699 } /* Name.Variable.Magic */ .highlight .il { color: #0000DD; font-weight: bold } /* Literal.Number.Integer.Long */
/* $Id: HD44780.c,v 1.49 2004/01/09 04:16:06 reinelt Exp $
 *
 * driver for display modules based on the HD44780 chip
 *
 * Copyright 1999-2004 Michael Reinelt <reinelt@eunet.at>
 *
 * Modification for 4-Bit mode
 * Copyright 2003 Martin Hejl (martin@hejl.de)
 *
 * Modification for 2nd controller support
 * Copyright 2003 Jesse Brook Kovach <jkovach@wam.umd.edu>
 *
 * 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: HD44780.c,v $
 * Revision 1.49  2004/01/09 04:16:06  reinelt
 * added 'section' argument to cfg_get(), but NULLed it on all calls by now.
 *
 * Revision 1.48  2004/01/06 22:33:13  reinelt
 * Copyright statements cleaned up
 *
 * Revision 1.47  2003/11/12 05:42:35  reinelt
 * small changes to the 16x4 handling
 *
 * Revision 1.46  2003/10/08 06:48:47  nicowallmeier
 * special handling for 16x4 displays
 *
 * Revision 1.45  2003/10/08 06:45:00  nicowallmeier
 * Support of two displays of the same size
 *
 * Revision 1.44  2003/10/05 17:58:50  reinelt
 * libtool junk; copyright messages cleaned up
 *
 * Revision 1.43  2003/09/29 06:12:56  reinelt
 * changed default HD44780 wiring: unused signals are GND
 *
 * Revision 1.42  2003/09/21 06:43:02  reinelt
 *
 *
 * MatrixOrbital: bidirectional communication
 * HD44780: special handling for 16x1 displays (thanks to Maciej Witkowiak)
 *
 * Revision 1.41  2003/09/13 06:20:39  reinelt
 * HD44780 timings changed; deactivated libtool
 *
 * Revision 1.40  2003/09/11 04:09:52  reinelt
 * minor cleanups
 *
 * Revision 1.39  2003/09/10 03:48:22  reinelt
 * Icons for M50530, new processing scheme (Ticks.Text...)
 *
 * Revision 1.38  2003/09/09 11:47:47  reinelt
 * basic icon support for HD44780
 *
 * Revision 1.37  2003/09/09 06:54:43  reinelt
 * new function 'cfg_number()'
 *
 * Revision 1.36  2003/08/24 05:17:58  reinelt
 * liblcd4linux patch from Patrick Schemitz
 *
 * Revision 1.35  2003/08/22 03:45:08  reinelt
 * bug in parallel port code fixed, more icons stuff
 *
 * Revision 1.34  2003/08/19 05:23:55  reinelt
 * HD44780 dual-controller patch from Jesse Brook Kovach
 *
 * Revision 1.33  2003/08/19 04:28:41  reinelt
 * more Icon stuff, minor glitches fixed
 *
 * Revision 1.32  2003/08/16 07:31:35  reinelt
 * double buffering in all drivers
 *
 * Revision 1.31  2003/08/15 07:54:07  reinelt
 * HD44780 4 bit mode implemented
 *
 * Revision 1.30  2003/08/12 05:10:31  reinelt
 * first version of HD44780 4Bit-Mode patch
 *
 * Revision 1.29  2003/07/24 04:48:09  reinelt
 * 'soft clear' needed for virtual rows
 *
 * Revision 1.28  2003/04/07 06:02:58  reinelt
 * further parallel port abstraction
 *
 * Revision 1.27  2003/04/04 06:01:59  reinelt
 * new parallel port abstraction scheme
 *
 * Revision 1.26  2003/02/22 07:53:09  reinelt
 * cfg_get(key,defval)
 *
 * Revision 1.25  2002/08/19 09:11:34  reinelt
 * changed HD44780 to use generic bar functions
 *
 * Revision 1.24  2002/08/19 07:36:29  reinelt
 *
 * finished bar.c, USBLCD is the first driver that uses the generic bar functions
 *
 * Revision 1.23  2002/08/19 04:41:20  reinelt
 * introduced bar.c, moved bar stuff from display.h to bar.h
 *
 * Revision 1.22  2002/08/17 14:14:21  reinelt
 *
 * USBLCD fixes
 *
 * Revision 1.21  2002/04/30 07:20:15  reinelt
 *
 * implemented the new ndelay(nanoseconds) in all parallel port drivers
 *
 * Revision 1.20  2001/09/09 12:26:03  reinelt
 * GPO bug: INIT is _not_ inverted
 *
 * Revision 1.19  2001/03/15 15:49:22  ltoetsch
 * fixed compile HD44780.c, cosmetics
 *
 * Revision 1.18  2001/03/15 09:47:13  reinelt
 *
 * some fixes to ppdef
 * off-by-one bug in processor.c fixed
 *
 * Revision 1.17  2001/03/14 16:47:41  reinelt
 * minor cleanups
 *
 * Revision 1.16  2001/03/14 15:30:53  reinelt
 *
 * make ppdev compatible to earlier kernels
 *
 * Revision 1.15  2001/03/14 15:14:59  reinelt
 * added ppdev parallel port access
 *
 * Revision 1.14  2001/03/12 13:44:58  reinelt
 *
 * new udelay() using Time Stamp Counters
 *
 * Revision 1.13  2001/03/12 12:39:36  reinelt
 *
 * reworked autoconf a lot: drivers may be excluded, #define's went to config.h
 *
 * Revision 1.12  2001/02/14 07:40:16  reinelt
 *
 * first (incomplete) GPO implementation
 *
 * Revision 1.11  2001/02/13 12:43:24  reinelt
 *
 * HD_gpo() was missing
 *
 * Revision 1.10  2001/02/13 09:00:13  reinelt
 *
 * prepared framework for GPO's (general purpose outputs)
 *
 * Revision 1.9  2000/10/20 07:17:07  reinelt
 *
 *
 * corrected a bug in HD_goto()
 * Thanks to Gregor Szaktilla <gregor@szaktilla.de>
 *
 * Revision 1.8  2000/08/10 09:44:09  reinelt
 *
 * new debugging scheme: error(), info(), debug()
 * uses syslog if in daemon mode
 *
 * Revision 1.7  2000/08/09 09:50:29  reinelt
 *
 * opened 0.98 development
 * removed driver-specific signal-handlers
 * added 'quit'-function to driver structure
 * added global signal-handler
 *
 * Revision 1.6  2000/07/31 10:43:44  reinelt
 *
 * some changes to support kernel-2.4 (different layout of various files in /proc)
 *
 * Revision 1.5  2000/07/31 06:46:35  reinelt
 *
 * eliminated some compiler warnings with glibc
 *
 * Revision 1.4  2000/04/15 16:56:52  reinelt
 *
 * moved delay loops to udelay.c
 * renamed -d (debugging) switch to -v (verbose)
 * new switch -d to calibrate delay loop
 * 'Delay' entry for HD44780 back again
 * delay loops will not calibrate automatically, because this will fail with hich CPU load
 *
 * Revision 1.3  2000/04/15 11:13:54  reinelt
 *
 * added '-d' (debugging) switch
 * added several debugging messages
 * removed config entry 'Delay' for HD44780 driver
 * delay loop for HD44780 will be calibrated automatically
 *
 * Revision 1.2  2000/04/13 06:09:52  reinelt
 *
 * added BogoMips() to system.c (not used by now, maybe sometimes we can
 * calibrate our delay loop with this value)
 *
 * added delay loop to HD44780 driver. It seems to be quite fast now. Hopefully
 * no compiler will optimize away the delay loop!
 *
 * Revision 1.1  2000/04/12 08:05:45  reinelt
 *
 * first version of the HD44780 driver
 *
 */

/* 
 *
 * exported fuctions:
 *
 * struct LCD HD44780[]
 *
 */

#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "debug.h"
#include "cfg.h"
#include "display.h"
#include "bar.h"
#include "icon.h"
#include "parport.h"
#include "udelay.h"

#define XRES 5
#define YRES 8
#define CHARS 8



/* low level communication timings [nanoseconds]
 * as these values differ from spec to spec,
 * we use the worst-case values.
 */

#define T_CYCLE 1000 // Enable cycle time
#define T_PW     450 // Enable pulse width
#define T_AS      60 // Address setup time
#define T_H       40 // Data hold time


/* HD44780 execution timings [microseconds]
 * as these values differ from spec to spec,
 * we use the worst-case values.
 */

#define T_INIT1 4100 // first init sequence:  4.1 msec
#define T_INIT2  100 // second init sequence: 100 usec
#define T_EXEC    80 // normal execution time
#define T_WRCG   120 // CG RAM Write
#define T_CLEAR 1640 // Clear Display


static LCD Lcd;
static int Icons;
static int Bits=0;
static int GPO=0;
static int Controllers = 0;
static int Controller  = 0;

static char *FrameBuffer1=NULL;
static char *FrameBuffer2=NULL;

static unsigned char SIGNAL_RW;
static unsigned char SIGNAL_RS;
static unsigned char SIGNAL_ENABLE;
static unsigned char SIGNAL_ENABLE2;
static unsigned char SIGNAL_GPO;

static void HD_nibble(unsigned char controller, unsigned char nibble)
{
  unsigned char enable;

  // enable signal: 'controller' is a bitmask
  // bit 0 .. send to controller #0
  // bit 1 .. send to controller #1
  // so we can send a byte to both controllers at the same time!
  enable=0;
  if (controller&0x01) enable|=SIGNAL_ENABLE;
  if (controller&0x02) enable|=SIGNAL_ENABLE2;
  
  // clear ENABLE
  // put data on DB1..DB4
  // nibble already contains RS bit!
  parport_data(nibble);

  // Address set-up time
  ndelay(T_AS);
  
  // rise ENABLE
  parport_data(nibble | enable);
  
  // Enable pulse width
  ndelay(T_PW);

  // lower ENABLE
  parport_data(nibble);
}


static void HD_byte (unsigned char controller, unsigned char data, unsigned char RS)
{
  // send high nibble of the data
  HD_nibble (controller, ((data>>4)&0x0f)|RS);

  // Make sure we honour T_CYCLE
  ndelay(T_CYCLE-T_AS-T_PW);

  // send low nibble of the data
  HD_nibble(controller, (data&0x0f)|RS);
}


static void HD_command (unsigned char controller, unsigned char cmd, int delay)
{
  unsigned char enable;
   
  if (Bits==8) {
    
    // enable signal: 'controller' is a bitmask
    // bit 0 .. send to controller #0
    // bit 1 .. send to controller #1
    // so we can send a byte to both controllers at the same time!
    enable=0;
    if (controller&0x01) enable|=SIGNAL_ENABLE;
    if (controller&0x02) enable|=SIGNAL_ENABLE2;
    
    // put data on DB1..DB8
    parport_data (cmd);
  
    // clear RW and RS
    parport_control (SIGNAL_RW | SIGNAL_RS, 0);
    
    // Address set-up time
    ndelay(T_AS);

    // send command
    parport_toggle (enable, 1, T_PW);
    
  } else {

    HD_byte (controller, cmd, 0);

  }
  
  // wait for command completion
  udelay(delay);

}


static void HD_write (unsigned char controller, char *string, int len, int delay)
{
  unsigned char enable;

  // sanity check
  if (len<=0) return;

  if (Bits==8) {

    // enable signal: 'controller' is a bitmask
    // bit 0 .. send to controller #0
    // bit 1 .. send to controller #1
    // so we can send a byte to both controllers at the same time!
    enable=0;
    if (controller&0x01) enable|=SIGNAL_ENABLE;
    if (controller&0x02) enable|=SIGNAL_ENABLE2;
    
    // clear RW, set RS
    parport_control (SIGNAL_RW | SIGNAL_RS, SIGNAL_RS);

    // Address set-up time
    ndelay(T_AS);
    
    while (len--) {
      
      // put data on DB1..DB8
      parport_data (*(string++));
      
      // send command
      parport_toggle (enable, 1, T_PW);
      
      // wait for command completion
      udelay(delay);
    }
    
  } else { // 4 bit mode
    
    while (len--) {

      // send data with RS enabled
      HD_byte (controller, *(string++), SIGNAL_RS);
      
      // wait for command completion
      udelay(delay);
    }
  }
}


static void HD_setGPO (int bits)
{
  if (Lcd.gpos>0) {
    
    // put data on DB1..DB8
    parport_data (bits);
    
    // 74HCT573 set-up time
    ndelay(20);
    
    // send data
    // 74HCT573 enable pulse width = 24ns
    parport_toggle (SIGNAL_GPO, 1, 230);
  }
}


static void HD_define_char (int ascii, char *buffer)
{
  // define chars on *both* controllers!
  HD_command (0x03, 0x40|8*ascii, T_EXEC);
  HD_write (0x03, buffer, 8, T_WRCG);
}


int HD_clear (int full)
{

  memset (FrameBuffer1, ' ', Lcd.rows*Lcd.cols*sizeof(char));

  icon_clear();
  bar_clear();

  GPO=0;
  
  if (full) {
    memset (FrameBuffer2, ' ', Lcd.rows*Lcd.cols*sizeof(char));
    HD_command (0x03, 0x01, T_CLEAR); // clear *both* displays
    HD_command (0x03, 0x03, T_CLEAR); // return home
    HD_setGPO (GPO);                  // all GPO's off
  }
  
  return 0;
}


int HD_init (LCD *Self)
{
  int rows=-1, cols=-1, gpos=-1;
  char *s;
  
  s=cfg_get(NULL, "Size", NULL);
  if (s==NULL || *s=='\0') {
    error ("HD44780: no 'Size' entry in %s", cfg_source());
    return -1;
  }
  if (sscanf(s,"%dx%d",&cols,&rows)!=2 || rows<1 || cols<1) {
    error ("HD44780: bad size '%s'",s);
    return -1;
  }
  
  if (cfg_number(NULL, "GPOs", 0, 0, 8, &gpos)<0) return -1;
  info ("HD44780: controlling %d GPO's", gpos);

  if (cfg_number(NULL, "Controllers", 1, 1, 2, &Controllers)<0) return -1;
  info ("wiring: using display with %d controllers", Controllers);
  
  // current controller
  Controller=1;
  
  Self->rows=rows;
  Self->cols=cols;
  Self->gpos=gpos;
  Lcd=*Self;
  
  // Init the framebuffers
  FrameBuffer1 = (char*)malloc(Lcd.cols*Lcd.rows*sizeof(char));
  FrameBuffer2 = (char*)malloc(Lcd.cols*Lcd.rows*sizeof(char));
  if (FrameBuffer1==NULL || FrameBuffer2==NULL) {
    error ("HD44780: framebuffer could not be allocated: malloc() failed");
    return -1;
  }
  
  if (cfg_number(NULL, "Bits", 8, 4, 8, &Bits)<0) return -1;
  if (Bits!=4 && Bits!=8) {
    error ("HD44780: bad Bits '%s' in %s, should be '4' or '8'", s, cfg_source());
    return -1;
  }    
  info ("wiring: using %d bit mode", Bits);
  
  if (Bits==8) {
    if ((SIGNAL_RS      = parport_wire_ctrl ("RS",      "AUTOFD"))==0xff) return -1;
    if ((SIGNAL_RW      = parport_wire_ctrl ("RW",      "GND"   ))==0xff) return -1;
    if ((SIGNAL_ENABLE  = parport_wire_ctrl ("ENABLE",  "STROBE"))==0xff) return -1;
    if ((SIGNAL_ENABLE2 = parport_wire_ctrl ("ENABLE2", "GND"   ))==0xff) return -1;
    if ((SIGNAL_GPO     = parport_wire_ctrl ("GPO",     "GND"   ))==0xff) return -1;
  } else {
    if ((SIGNAL_RS      = parport_wire_data ("RS",      "DB4"))==0xff) return -1;
    if ((SIGNAL_RW      = parport_wire_data ("RW",      "DB5"))==0xff) return -1;
    if ((SIGNAL_ENABLE  = parport_wire_data ("ENABLE",  "DB6"))==0xff) return -1;
    if ((SIGNAL_ENABLE2 = parport_wire_data ("ENABLE2", "GND"))==0xff) return -1;
    if ((SIGNAL_GPO     = parport_wire_data ("GPO",     "GND"))==0xff) return -1;
  }
  
  if (parport_open() != 0) {
    error ("HD44780: could not initialize parallel port!");
    return -1;
  }

  // clear all signals
  if (Bits==8) {
    parport_control (SIGNAL_RS|SIGNAL_RW|SIGNAL_ENABLE|SIGNAL_ENABLE2|SIGNAL_GPO, 0);
  } else {
    parport_data (0);
  }

  // set direction: write
  parport_direction (0);

  // initialize *both* displays
  if (Bits==8) {
    HD_command (0x03, 0x30, T_INIT1); // 8 Bit mode, wait 4.1 ms
    HD_command (0x03, 0x30, T_INIT2); // 8 Bit mode, wait 100 us
    HD_command (0x03, 0x38, T_EXEC);  // 8 Bit mode, 1/16 duty cycle, 5x8 font
  } else {
    HD_nibble(0x03, 0x03); udelay(T_INIT1); // 4 Bit mode, wait 4.1 ms
    HD_nibble(0x03, 0x03); udelay(T_INIT2); // 4 Bit mode, wait 100 us
    HD_nibble(0x03, 0x03); udelay(T_INIT1); // 4 Bit mode, wait 4.1 ms
    HD_nibble(0x03, 0x02); udelay(T_INIT2); // 4 Bit mode, wait 100 us
    HD_command (0x03, 0x28, T_EXEC);	    // 4 Bit mode, 1/16 duty cycle, 5x8 font
  }
  
  HD_command (0x03, 0x08, T_EXEC);  // Display off, cursor off, blink off
  HD_command (0x03, 0x0c, T_CLEAR); // Display on, cursor off, blink off, wait 1.64 ms
  HD_command (0x03, 0x06, T_EXEC);  // curser moves to right, no shift

  if (cfg_number(NULL, "Icons", 0, 0, CHARS, &Icons)<0) return -1;
  if (Icons>0) {
    debug ("reserving %d of %d user-defined characters for icons", Icons, CHARS);
    icon_init(Lcd.rows, Lcd.cols, XRES, YRES, CHARS, Icons, HD_define_char);
    Self->icons=Icons;
    Lcd.icons=Icons;
  }
  
  bar_init(rows, cols, XRES, YRES, CHARS-Icons);
  bar_add_segment(  0,  0,255, 32); // ASCII  32 = blank
  bar_add_segment(255,255,255,255); // ASCII 255 = block
  
  HD_clear(1);
  
  return 0;
}


void HD_goto (int row, int col)
{
  int pos;

  // handle multiple displays/controllers
  if (Controllers>1 && row>=Lcd.rows/2) {
    row -= Lcd.rows/2;
    Controller = 2;
  } else {
    Controller = 1;
  }
   
  // 16x1 Displays are organized as 8x2 :-(
  if (Lcd.cols==16 && Lcd.rows==1 && col>7) {
    row++;
    col-=8;
  }
  
  // 16x4 Displays use a slightly different layout
  if (Lcd.cols==16 && Lcd.rows==4) {
    pos=(row%2)*64+(row/2)*16+col;
  } else {  
    pos=(row%2)*64+(row/2)*20+col;
  }
  
  HD_command (Controller, (0x80|pos), T_EXEC);
}


int HD_put (int row, int col, char *text)
{
  char *p=FrameBuffer1+row*Lcd.cols+col;
  char *t=text;
  
  while (*t && col++<=Lcd.cols) {
    *p++=*t++;
  }
  return 0;
}


int HD_bar (int type, int row, int col, int max, int len1, int len2)
{
  return bar_draw (type, row, col, max, len1, len2);
}


int HD_icon (int num, int seq, int row, int col)
{
  return icon_draw (num, seq, row, col);
}


int HD_gpo (int num, int val)
{
  if (num>=Lcd.gpos) 
    return -1;

  if (val) {
    GPO |= 1<<num;     // set bit
  } else {
    GPO &= ~(1<<num);  // clear bit
  }
  return 0;
}


int HD_flush (void)
{
  int row, col, pos1, pos2;
  int c, equal;
  
  bar_process(HD_define_char);

  for (row=0; row<Lcd.rows; row++) {
    for (col=0; col<Lcd.cols; col++) {
      c=bar_peek(row, col);
      if (c==-1) c=icon_peek(row, col);
      if (c!=-1) {
	FrameBuffer1[row*Lcd.cols+col]=(char)c;
      }
    }
    for (col=0; col<Lcd.cols; col++) {
      if (FrameBuffer1[row*Lcd.cols+col]==FrameBuffer2[row*Lcd.cols+col]) continue;
      HD_goto (row, col);
      for (pos1=col++, pos2=pos1, equal=0; col<Lcd.cols; col++) {
	if (FrameBuffer1[row*Lcd.cols+col]==FrameBuffer2[row*Lcd.cols+col]) {
	  // If we find just one equal byte, we don't break, because this 
	  // would require a goto, which takes one byte, too.
	  if (++equal>2) break;
	} else {
	  pos2=col;
	  equal=0;
	}
	// special handling of 16x1 displays
	if (Lcd.rows==1 && Lcd.cols==16 && col==7) {
	  break;
	}
      }
      HD_write (Controller, FrameBuffer1+row*Lcd.cols+pos1, pos2-pos1+1, T_EXEC);
    }
  }

  memcpy (FrameBuffer2, FrameBuffer1, Lcd.rows*Lcd.cols*sizeof(char));

  HD_setGPO(GPO);

  return 0;
}


int HD_quit (void)
{
  info("HD44780: shutting down.");

  if (FrameBuffer1) {
    free(FrameBuffer1);
    FrameBuffer1=NULL;
  }

  if (FrameBuffer2) {
    free(FrameBuffer2);
    FrameBuffer2=NULL;
  }

  return parport_close();
}


LCD HD44780[] = {
  { name: "HD44780",
    rows:  0,
    cols:  0,
    xres:  XRES,
    yres:  YRES,
    bars:  BAR_L | BAR_R | BAR_U | BAR_D | BAR_H2,
    icons: 0,
    gpos:  0,
    init:  HD_init,
    clear: HD_clear,
    put:   HD_put,
    bar:   HD_bar,
    icon:  HD_icon,
    gpo:   HD_gpo,
    flush: HD_flush,
    quit:  HD_quit 
  },
  { NULL }
};