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Support for nanosleep and gettimeofday delay methods added

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This commit is contained in:
cstein
2000-07-25 22:12:21 +00:00
parent 0c07dacfea
commit af99913d34
2 changed files with 81 additions and 3 deletions
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server/drivers/hd44780-winamp.c
+21 -3
View File
@@ -6,6 +6,11 @@
* Copyright (c) 1999 Andrew McMeikan <andrewm@engineer.com>
* modular driver 1999-2000 Benjamin Tse <blt@Comports.com>
*
* Modified July 2000 by Charles Steinkuehler for enhanced
* performance and reduced CPU usage
* - provided required setup time for RS valid to E high
* - 1 uS call to uPause removed as it is unnecessary
*
* The connections are:
* printer port LCD
* D0 (2) D0 (7)
@@ -93,8 +98,21 @@ lcdwinamp_HD44780_senddata (unsigned char displayID, unsigned char flags, unsign
else
dispID = EnMask[displayID - 1];
port_out (lptPort, ch);
port_out (lptPort + 2, (dispID | portControl) ^ OUTMASK);
hd44780_functions->uPause (1);
// 40 nS setup time for RS valid to EN high, so set RS
port_out (lptPort + 2, portControl ^ OUTMASK);
// then set EN high
port_out (lptPort + 2, (dispID | portControl) ^ OUTMASK);
// Output the actual data
port_out (lptPort, ch);
// 80 nS setup from valid data to EN low will be met without any delay
// unless you are running a REALLY FAST ISA bus (like 75 MHZ!)
// 230 nS minimum E high time provided by ISA bus delays as well...
// Set EN low and we're done...
port_out (lptPort + 2, portControl ^ OUTMASK);
// 10 nS data hold time provided by the length of ISA write for EN
}
server/drivers/hd44780.c
+60
View File
@@ -16,10 +16,15 @@
* Modular driver created and generic support for multiple displays added
* Dec 1999, Benjamin Tse <blt@Comports.com>
*
* Modified July 2000 by Charles Steinkuehler to use one of 3 methods for delay
* timing. I/O reads, gettimeofday, and nanosleep. Of the three, nanosleep
* seems to work best, so that's what is set by default.
*
* This file is released under the GNU General Public License. Refer to the
* COPYING file distributed with this package.
*
* Copyright (c) 2000, 1999, 1995 Benjamin Tse <blt@Comports.com>
* 2000, Charles Steinkuehler <cstein@newtek.com>
* 1999 Andrew McMeikan <andrewm@engineer.com>
* 1998 Richard Rognlie <rrognlie@gamerz.net>
* 1997 Matthias Prinke <m.prinke@trashcan.mcnet.de>
@@ -33,6 +38,22 @@
#include <errno.h>
#include <sys/perm.h>
// Uncomment one of the lines below to select your desired delay generation
// mechanism. If both defines are commented, the original I/O read timing
// loop is used. Using DELAY_NANOSLEEP seems to provide the best performance.
//#define DELAY_GETTIMEOFDAY
#define DELAY_NANOSLEEP
#if defined DELAY_GETTIMEOFDAY
#include <sys/time.h>
#include <unistd.h>
// Only one alternate delay method at a time, please ;-)
#undef DELAY_NANOSLEEP
#elif defined DELAY_NANOSLEEP
#include <sched.h>
#include <time.h>
#endif
#include "../../shared/str.h"
#include "lcd.h"
@@ -209,6 +230,18 @@ HD44780_init (lcd_logical_driver * driver, char *args)
} else
fprintf (stderr, "Error mallocing for display sizes list\n");
}
#if defined DELAY_NANOSLEEP
// Change to Round-Robin scheduling for nanosleep
{
// Set priority to 1
struct sched_param param;
param.sched_priority=1;
if (( sched_setscheduler(0, SCHED_RR, &param)) == -1) {
fprintf (stderr, "HD44780_init: failed (%s)\n", strerror (errno));
return -1;
}
}
#endif
// Set up io port correctly, and open it...
if ((ioperm (port, 1, 255)) == -1) {
fprintf (stderr, "HD44780_init: failed (%s)\n", strerror (errno));
@@ -293,10 +326,37 @@ common_init (enum ifWidth ifwidth)
void
uPause (int delayCalls)
{
#if defined DELAY_GETTIMEOFDAY
struct timeval current_time,delay_time,wait_time;
// Get current time first thing
gettimeofday(&current_time,NULL);
// Calculate when delay is over
delay_time.tv_sec = 0;
delay_time.tv_usec = delayCalls;
timeradd(&current_time,&delay_time,&wait_time);
do {
gettimeofday(&current_time,NULL);
} while (timercmp(&current_time,&wait_time,<));
#elif defined DELAY_NANOSLEEP
struct timespec delay,remaining;
delay.tv_sec = 0;
delay.tv_nsec = delayCalls * 1000;
while ( nanosleep(&delay,&remaining) == -1 )
{
delay.tv_sec = remaining.tv_sec;
delay.tv_nsec = remaining.tv_nsec;
}
#else
int i;
for (i = 0; i < delayCalls; ++i)
port_in (port);
//TODO: put in option for nanosleep rather than dummy I/O call
#endif
}
// displayID - ID of display to use (0 = all displays)